1
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Reba SM, Li Q, Onwuzulike S, Nagy N, Fletcher S, Parker K, Shaw RJ, Umphred-Wilson K, Shukla S, Harding CV, Boom WH, Rojas RE. TLR2 on CD4+ and CD8+ T cells promotes control of Mycobacterium tuberculosis infection. Eur J Immunol 2024:e2350715. [PMID: 38446066 DOI: 10.1002/eji.202350715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 03/07/2024]
Abstract
Although a role for TLR2 on T cells has been indicated in prior studies, in vivo stimulation of TLR2 on T cells by Mtb and its impact on Mtb infection has not been tested. Furthermore, it is not known if the enhanced susceptibility to Mtb of Tlr2 gene knockout mice is due to its role in macrophages, T cells, or both. To address TLR2 on T cells, we generated Tlr2fl/fl xCd4cre/cre mice, which lack expression of TLR2 on both CD4 and CD8 T cells, to study the in vivo role of TLR2 on T cells after aerosol infection with virulent Mtb. Deletion of TLR2 in CD4+ and CD8+ T cells reduces their ability to be co-stimulated by TLR2 ligands for cytokine production. These include both pro- (IFN-γ, TNF-α) and anti-inflammatory cytokines (IL-10). Deletion of TLR2 in T cells affected control of Mtb in the lungs and spleens of infected mice. This suggests that T-cell co-stimulation by mycobacterial TLR2 ligands in vivo contributes to the control of Mtb infection in the lung and spleen.
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Affiliation(s)
- Scott M Reba
- Department of Medicine, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - Qing Li
- Department of Medicine, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - Sophia Onwuzulike
- Department of Medicine, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - Nancy Nagy
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Shane Fletcher
- Department of Medicine, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - Kyle Parker
- Department of Medicine, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - Rachel J Shaw
- Department of Medicine, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - Katharine Umphred-Wilson
- Department of Medicine, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - Supriya Shukla
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Clifford V Harding
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, USA
| | - W Henry Boom
- Department of Medicine, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
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2
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Mwebaza I, Shaw R, Li Q, Fletcher S, Achkar JM, Harding CV, Carpenter SM, Boom WH. Impact of Mycobacterium tuberculosis Glycolipids on the CD4+ T Cell-Macrophage Immunological Synapse. J Immunol 2023; 211:1385-1396. [PMID: 37695687 PMCID: PMC10579150 DOI: 10.4049/jimmunol.2300107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 08/24/2023] [Indexed: 09/13/2023]
Abstract
Mycobacterium tuberculosis cell-wall glycolipids such as mannosylated lipoarabinomannan (ManLAM) can inhibit murine CD4+ T cells by blocking TCR signaling. This results in suppression of IL-2 production, reduced T cell proliferation, and induction of CD4+ T cell anergy. This study extended these findings to the interaction between primary human CD4+ T cells and macrophages infected by mycobacteria. Exposure of human CD4+ T cells to ManLAM before activation resulted in loss of polyfunctionality, as measured by IL-2, IFN-γ, and TNF-α expression, and reduced CD25 expression. This was not associated with upregulation of inhibitory receptors CTLA-4, PD-1, TIM-3, and Lag-3. By confocal microscopy and imaging flow cytometry, ManLAM exposure reduced conjugate formation between macrophages and CD4+ T cells. ManLAM colocalized to the immunological synapse (IS) and reduced translocation of lymphocyte-specific protein tyrosine kinase (LCK) to the IS. When CD4+ T cells and Mycobacterium bovis BCG-infected monocytes were cocultured, ManLAM colocalized to CD4+ T cells, which formed fewer conjugates with infected monocytes. These results demonstrate that mycobacterial cell-wall glycolipids such as ManLAM can traffic from infected macrophages to disrupt productive IS formation and inhibit CD4+ T cell activation, contributing to immune evasion by M. tuberculosis.
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Affiliation(s)
- Ivan Mwebaza
- Department of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH
| | - Rachel Shaw
- Department of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH
| | - Qing Li
- Department of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH
| | - Shane Fletcher
- Department of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH
| | | | - Clifford V. Harding
- Department of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH
- Department of Pathology, Case Western Reserve University, Cleveland, OH
| | - Stephen M. Carpenter
- Department of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH
- Department of Pathology, Case Western Reserve University, Cleveland, OH
| | - W. Henry Boom
- Department of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH
- Department of Pathology, Case Western Reserve University, Cleveland, OH
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3
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Engelhart MJ, Glowacki RWP, Till JM, Harding CV, Martens EC, Ahern PP. The NQR Complex Regulates the Immunomodulatory Function of Bacteroides thetaiotaomicron. J Immunol 2023; 211:767-781. [PMID: 37486212 PMCID: PMC10527448 DOI: 10.4049/jimmunol.2200892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 06/26/2023] [Indexed: 07/25/2023]
Abstract
The gut microbiome and intestinal immune system are engaged in a dynamic interplay that provides myriad benefits to host health. However, the microbiome can also elicit damaging inflammatory responses, and thus establishing harmonious immune-microbiome interactions is essential to maintain homeostasis. Gut microbes actively coordinate the induction of anti-inflammatory responses that establish these mutualistic interactions. Despite this, the microbial pathways that govern this dialogue remain poorly understood. We investigated the mechanisms through which the gut symbiont Bacteroides thetaiotaomicron exerts its immunomodulatory functions on murine- and human-derived cells. Our data reveal that B. thetaiotaomicron stimulates production of the cytokine IL-10 via secreted factors that are packaged into outer membrane vesicles, in a TLR2- and MyD88-dependent manner. Using a transposon mutagenesis-based screen, we identified a key role for the B. thetaiotaomicron-encoded NADH:ubiquinone oxidoreductase (NQR) complex, which regenerates NAD+ during respiration, in this process. Finally, we found that disruption of NQR reduces the capacity of B. thetaiotaomicron to induce IL-10 by impairing biogenesis of outer membrane vesicles. These data identify a microbial pathway with a previously unappreciated role in gut microbe-mediated immunomodulation that may be targeted to manipulate the capacity of the microbiome to shape host immunity.
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Affiliation(s)
- Morgan J. Engelhart
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Robert W. P. Glowacki
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Jessica M. Till
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Clifford V. Harding
- Department of Pathology, Case Western Reserve University/University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | - Eric C. Martens
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Philip P. Ahern
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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4
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Yoshimoto T, Kittaka M, Doan AAP, Urata R, Prideaux M, Rojas RE, Harding CV, Henry Boom W, Bonewald LF, Greenfield EM, Ueki Y. Osteocytes directly regulate osteolysis via MYD88 signaling in bacterial bone infection. Nat Commun 2022; 13:6648. [PMID: 36333322 PMCID: PMC9636212 DOI: 10.1038/s41467-022-34352-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022] Open
Abstract
The impact of bone cell activation on bacterially-induced osteolysis remains elusive. Here, we show that matrix-embedded osteocytes stimulated with bacterial pathogen-associated molecular patterns (PAMPs) directly drive bone resorption through an MYD88-regulated signaling pathway. Mice lacking MYD88, primarily in osteocytes, protect against osteolysis caused by calvarial injections of bacterial PAMPs and resist alveolar bone resorption induced by oral Porphyromonas gingivalis (Pg) infection. In contrast, mice with targeted MYD88 restoration in osteocytes exhibit osteolysis with inflammatory cell infiltration. In vitro, bacterial PAMPs induce significantly higher expression of the cytokine RANKL in osteocytes than osteoblasts. Mechanistically, activation of the osteocyte MYD88 pathway up-regulates RANKL by increasing binding of the transcription factors CREB and STAT3 to Rankl enhancers and by suppressing K48-ubiquitination of CREB/CREB binding protein and STAT3. Systemic administration of an MYD88 inhibitor prevents jawbone loss in Pg-driven periodontitis. These findings reveal that osteocytes directly regulate inflammatory osteolysis in bone infection, suggesting that MYD88 and downstream RANKL regulators in osteocytes are therapeutic targets for osteolysis in periodontitis and osteomyelitis.
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Affiliation(s)
- Tetsuya Yoshimoto
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202-5126, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Mizuho Kittaka
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202-5126, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Andrew Anh Phuong Doan
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202-5126, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Rina Urata
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202-5126, USA
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Matthew Prideaux
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | | | - Clifford V Harding
- Department of Pathology, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, OH, 44106-4960, USA
| | - W Henry Boom
- Department of Pathology, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, OH, 44106-4960, USA
- Department of Medicine, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, OH, 44106-4960, USA
- Department of Molecular Biology and Microbiology, Case Western Reserve University & University Hospitals Cleveland Medical Center, Cleveland, OH, 44106-4960, USA
| | - Lynda F Bonewald
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Edward M Greenfield
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA
| | - Yasuyoshi Ueki
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN, 46202-5126, USA.
- Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN, 46202-5126, USA.
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5
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Stefaniuk CM, Schlegelmilch J, Meyerson HJ, Harding CV, Maitta RW. Initial assessment of α-synuclein structure in platelets. J Thromb Thrombolysis 2021; 53:950-953. [PMID: 34797472 PMCID: PMC9117560 DOI: 10.1007/s11239-021-02607-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/07/2021] [Indexed: 11/24/2022]
Abstract
Over the last few years data from our group have indicated that α-synuclein is important in development of immune cells as well as potentially erythrocytes and platelets. The latter is important since this protein may work as negative regulator of granule release. Thus, we sought to begin to understand the structure of this protein in platelets. Flow cytometric analysis of this protein using region-specific (N-terminus, central region and C-terminus) monoclonal antibodies was performed. Antibody to the central region gave the strongest shift among all three antibodies, with the C-terminus having intermediate shift and N-terminus minimal shift. Western blotting using the same antibodies showed similar binding of all antibodies to α-synuclein. These results suggest a similar arrangement of this protein in platelets as seen in neurons. Future studies ought to look at the role that each protein region plays in platelets.
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Affiliation(s)
- Catherine M Stefaniuk
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - June Schlegelmilch
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Howard J Meyerson
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Clifford V Harding
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.,Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Robert W Maitta
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH, USA. .,Case Western Reserve University School of Medicine, Cleveland, OH, USA.
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6
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Chaudhary S, Ashok A, McDonald D, Wise AS, Kritikos AE, Rana NA, Harding CV, Singh N. Upregulation of Local Hepcidin Contributes to Iron Accumulation in Alzheimer's Disease Brains. J Alzheimers Dis 2021; 82:1487-1497. [PMID: 34180415 DOI: 10.3233/jad-210221] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Accumulation of iron is a consistent feature of Alzheimer's disease (AD) brains. The underlying cause, however, remains debatable. OBJECTIVE To explore whether local hepcidin synthesized by brain cells contributes to iron accumulation in AD brains. METHODS Brain tissue from the cingulate cortex of 33 cases of AD pre-assigned to Braak stage I-VI, 6 cases of non-dementia, and 15 cases of non-AD dementia were analyzed for transcriptional upregulation of hepcidin by RT-qPCR and RT-PCR. Change in the expression of ferritin, ferroportin (Fpn), microglial activation marker Iba1, IL-6, and TGFβ2 was determined by western blotting. Total tissue iron was determined by colorimetry. RESULTS Significant transcriptional upregulation of hepcidin was observed in Braak stage III-VI relative to Braak stage I and II, non-AD dementia, and non-dementia samples. Ferritin was increased in Braak stage V, and a significant increase in tissue iron was evident in Braak stage III-VI. The expression of Iba1 and IL-6 was also increased in Braak stage III-VI relative to Braak stage I and II and non-AD dementia samples. Amyloid-β plaques were absent in most Braak stage I and II samples, and present in Braak stage III-VI samples with few exceptions. CONCLUSION These observations suggest that upregulation of brain hepcidin is mediated by IL-6, a known transcriptional activator of hepcidin. The consequent downregulation of Fpn on neuronal and other cells results in accumulation of iron in AD brains. The increase in hepcidin is disease-specific, and increases with disease progression, implicating AD-specific pathology in the accumulation of iron.
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Affiliation(s)
- Suman Chaudhary
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Ajay Ashok
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Dallas McDonald
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Aaron S Wise
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Alexander E Kritikos
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Neil A Rana
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Clifford V Harding
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Neena Singh
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
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7
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Groft SG, Suzart V, Nagy N, Boom WH, Harding CV. Tpl2 Signaling Regulates Dendritic Cell Activation and Responding T Cell Differentiation Following Mycobacterium tuberculosis Infection. The Journal of Immunology 2021. [DOI: 10.4049/jimmunol.206.supp.112.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Abstract
Mycobacterium tuberculosis (Mtb) utilizes a number of immune evasion mechanisms in order to persist inside of host antigen-presenting cells. Dendritic cells (DCs) are important in restricting Mtb growth by migrating to draining lymph nodes and activating antigen-specific T cell responses, but the roles of DCs in Mtb infection require further study. This study investigated DC activation and functional outcomes following Mtb H37Ra-driven tumor progression locus 2 (Tpl2) signaling. The role of Tpl2 was interrogated genetically, utilizing bone marrow-derived DCs from Tpl2−/− mice. We assessed cytokine production via ELISA, mRNA levels via qRT-PCR, and expression of cell surface molecules via flow cytometry. In Mtb-treated DCs, genetic depletion of Tpl2 increased production of pro-inflammatory cytokines such as IL-12p40 and IL-6. Loss of Tpl2 in Mtb-treated DCs also led to decreased E-cadherin expression, and increased expression of Icam-1 (Cd54) and Mmp2, which are molecules involved in DC transmigration. Expression of Ccr7 and Ccr4 was also enhanced in Mtb-treated Tpl2−/− DCs, which correlated with improved migration of Tpl2−/− DCs towards CCL19 and CCL21 in vitro (assessed using a trans-well assay). When antigen-specific CD4+ T cells were co-cultured with Mtb-infected DCs, deletion of Tpl2−/− in the DCs resulted in increased T cell production of IFNγ and IL-2, as well as increased Tbet expression, indicative of enhanced Th1 polarization. Together, these data indicate that Mtb-induced Tpl2 signaling suppresses certain aspects of DC activation, leading to blunted Th1 responses against the pathogen.
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Affiliation(s)
- Sarah Grace Groft
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Vinicius Suzart
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Nancy Nagy
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - W Henry Boom
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
- 2Division of Infectious Diseases, Case Western Reserve University, Cleveland, OH
| | - Clifford V Harding
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
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Chung MK, Zidar DA, Bristow MR, Cameron SJ, Chan T, Harding CV, Kwon DH, Singh T, Tilton JC, Tsai EJ, Tucker NR, Barnard J, Loscalzo J. COVID-19 and Cardiovascular Disease: From Bench to Bedside. Circ Res 2021; 128:1214-1236. [PMID: 33856918 PMCID: PMC8048382 DOI: 10.1161/circresaha.121.317997] [Citation(s) in RCA: 191] [Impact Index Per Article: 63.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A pandemic of historic impact, coronavirus disease 2019 (COVID-19) has potential consequences on the cardiovascular health of millions of people who survive infection worldwide. Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), the etiologic agent of COVID-19, can infect the heart, vascular tissues, and circulating cells through ACE2 (angiotensin-converting enzyme 2), the host cell receptor for the viral spike protein. Acute cardiac injury is a common extrapulmonary manifestation of COVID-19 with potential chronic consequences. This update provides a review of the clinical manifestations of cardiovascular involvement, potential direct SARS-CoV-2 and indirect immune response mechanisms impacting the cardiovascular system, and implications for the management of patients after recovery from acute COVID-19 infection.
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Affiliation(s)
- Mina K. Chung
- Cleveland Clinic (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
- Cleveland Clinic Lerner College of Medicine (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
- Case Western Reserve University School of Medicine (M.K.C., D.A.Z., S.J.C., T.C., C.V.H., D.H.K., T.S., J.C.T.), OH
| | - David A. Zidar
- Case Western Reserve University School of Medicine (M.K.C., D.A.Z., S.J.C., T.C., C.V.H., D.H.K., T.S., J.C.T.), OH
- Louis Stokes Cleveland Veterans Affairs Medical Center, OH (D.A.Z.)
| | | | - Scott J. Cameron
- Cleveland Clinic (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
- Cleveland Clinic Lerner College of Medicine (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
- Case Western Reserve University School of Medicine (M.K.C., D.A.Z., S.J.C., T.C., C.V.H., D.H.K., T.S., J.C.T.), OH
| | - Timothy Chan
- Cleveland Clinic (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
- Cleveland Clinic Lerner College of Medicine (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
- Case Western Reserve University School of Medicine (M.K.C., D.A.Z., S.J.C., T.C., C.V.H., D.H.K., T.S., J.C.T.), OH
| | - Clifford V. Harding
- Case Western Reserve University School of Medicine (M.K.C., D.A.Z., S.J.C., T.C., C.V.H., D.H.K., T.S., J.C.T.), OH
| | - Deborah H. Kwon
- Cleveland Clinic (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
- Cleveland Clinic Lerner College of Medicine (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
- Case Western Reserve University School of Medicine (M.K.C., D.A.Z., S.J.C., T.C., C.V.H., D.H.K., T.S., J.C.T.), OH
| | - Tamanna Singh
- Cleveland Clinic (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
- Cleveland Clinic Lerner College of Medicine (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
- Case Western Reserve University School of Medicine (M.K.C., D.A.Z., S.J.C., T.C., C.V.H., D.H.K., T.S., J.C.T.), OH
| | - John C. Tilton
- Case Western Reserve University School of Medicine (M.K.C., D.A.Z., S.J.C., T.C., C.V.H., D.H.K., T.S., J.C.T.), OH
| | - Emily J. Tsai
- Columbia University Vagelos College of Physicians and Surgeons, New York (E.J.T.)
| | - Nathan R. Tucker
- Masonic Medical Research Institute, Utica, NY (N.R.T.)
- Cardiovascular Disease Initiative, Broad Institute of Harvard and MIT, Boston, MA (N.R.T.)
| | - John Barnard
- Cleveland Clinic (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
- Cleveland Clinic Lerner College of Medicine (M.K.C., S.J.C., T.C., D.H.K., T.S., J.B.), OH
| | - Joseph Loscalzo
- Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (J.L.)
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9
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Rosenfeld LE, Chung MK, Harding CV, Spagnolo P, Grunewald J, Appelbaum J, Sauer WH, Culver DA, Joglar JA, Lin BA, Jellis CL, Dickfeld TM, Kwon DH, Miller EJ, Cremer PC, Bogun F, Kron J, Bock A, Mehta D, Leis P, Siontis KC, Kaufman ES, Crawford T, Zimetbaum P, Zishiri ET, Singh JP, Ellenbogen KA, Chrispin J, Quadri S, Vincent LL, Patton KK, Kalbfleish S, Callahan TD, Murgatroyd F, Judson MA, Birnie D, Okada DR, Maulion C, Bhat P, Bellumkonda L, Blankstein R, Cheng RK, Farr MA, Estep JD. Arrhythmias in Cardiac Sarcoidosis Bench to Bedside: A Case-Based Review. Circ Arrhythm Electrophysiol 2021; 14:e009203. [PMID: 33591816 DOI: 10.1161/circep.120.009203] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cardiac sarcoidosis is a component of an often multiorgan granulomatous disease of still uncertain cause. It is being recognized with increasing frequency, mainly as the result of heightened awareness and new diagnostic tests, specifically cardiac magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography scans. The purpose of this case-based review is to highlight the potentially life-saving importance of making the early diagnosis of cardiac sarcoidosis using these new tools and to provide a framework for the optimal care of patients with this disease. We will review disease mechanisms as currently understood, associated arrhythmias including conduction abnormalities, and atrial and ventricular tachyarrhythmias, guideline-directed diagnostic criteria, screening of patients with extracardiac sarcoidosis, and the use of pacemakers and defibrillators in this setting. Treatment options, including those related to heart failure, and those which may help clarify disease mechanisms are included.
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Affiliation(s)
- Lynda E Rosenfeld
- Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, CT (L.E.R., E.J.M., C.M., L.B.)
| | - Mina K Chung
- Cleveland Clinic, OH (M.K.C., D.A.C., C.L.J., D.H.K., P.C.C., A.B., T.D.C., P.B., J.D.E.)
| | - Clifford V Harding
- Department of Pathology, Case Western Reserve University, Cleveland, OH (C.V.H.)
| | - Paolo Spagnolo
- Respiratory Disease Unit, Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padova, Italy (P.S.)
| | | | - Jason Appelbaum
- University of Maryland School of Medicine, Baltimore (J.A., T.-M.D.)
| | - William H Sauer
- Brigham and Women's Hospital (W.H.S., R.B.), Harvard Medical School, Boston, MA
| | - Daniel A Culver
- Cleveland Clinic, OH (M.K.C., D.A.C., C.L.J., D.H.K., P.C.C., A.B., T.D.C., P.B., J.D.E.)
| | - Jose A Joglar
- University of Texas-Southwestern Medical Center, Dallas (J.A.J.)
| | - Ben A Lin
- Keck School of Medicine, University of Southern California, Los Angeles (B.A.L.)
| | - Christine L Jellis
- Cleveland Clinic, OH (M.K.C., D.A.C., C.L.J., D.H.K., P.C.C., A.B., T.D.C., P.B., J.D.E.)
| | | | - Deborah H Kwon
- Cleveland Clinic, OH (M.K.C., D.A.C., C.L.J., D.H.K., P.C.C., A.B., T.D.C., P.B., J.D.E.)
| | - Edward J Miller
- Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, CT (L.E.R., E.J.M., C.M., L.B.)
| | - Paul C Cremer
- Cleveland Clinic, OH (M.K.C., D.A.C., C.L.J., D.H.K., P.C.C., A.B., T.D.C., P.B., J.D.E.)
| | - Frank Bogun
- University of Michigan Medical School, Ann Arbor (F.B., T.C.)
| | - Jordana Kron
- Virginia Commonwealth University School of Medicine, Richmond (J.K., K.A.E.)
| | - Ashley Bock
- Cleveland Clinic, OH (M.K.C., D.A.C., C.L.J., D.H.K., P.C.C., A.B., T.D.C., P.B., J.D.E.)
| | - Davendra Mehta
- Icahn School of Medicine Mount Sinai, New York City, NY (D.M., P.L.)
| | - Paul Leis
- Icahn School of Medicine Mount Sinai, New York City, NY (D.M., P.L.)
| | | | - Elizabeth S Kaufman
- Metro Health Campus, Case Western Reserve University, Cleveland, OH (E.S.K.)
| | - Thomas Crawford
- University of Michigan Medical School, Ann Arbor (F.B., T.C.)
| | - Peter Zimetbaum
- Beth Israel Deaconess Medical Center (P.Z.), Harvard Medical School, Boston, MA
| | - Edwin T Zishiri
- Michigan Heart and Vascular Institute, Ypsilanti, MI (E.T.Z.)
| | - Jagmeet P Singh
- Massachusetts General Hospital (J.P.S.), Harvard Medical School, Boston, MA
| | | | - Jonathan Chrispin
- Johns Hopkins University School of Medicine, Baltimore, MD (J.C., D.R.O.)
| | - Syed Quadri
- George Washington University School of Medicine, Washington DC (S.Q.)
| | - Logan L Vincent
- University of Washington School of Medicine, Seattle (L.L.V., K.K.P., R.K.C.)
| | - Kristen K Patton
- University of Washington School of Medicine, Seattle (L.L.V., K.K.P., R.K.C.)
| | | | - Thomas D Callahan
- Cleveland Clinic, OH (M.K.C., D.A.C., C.L.J., D.H.K., P.C.C., A.B., T.D.C., P.B., J.D.E.)
| | | | | | - David Birnie
- University of Ottawa Heart Institute, ON, Canada (D.B.)
| | - David R Okada
- Johns Hopkins University School of Medicine, Baltimore, MD (J.C., D.R.O.)
| | - Christopher Maulion
- Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, CT (L.E.R., E.J.M., C.M., L.B.)
| | - Pavan Bhat
- Cleveland Clinic, OH (M.K.C., D.A.C., C.L.J., D.H.K., P.C.C., A.B., T.D.C., P.B., J.D.E.)
| | - Lavanya Bellumkonda
- Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, CT (L.E.R., E.J.M., C.M., L.B.)
| | - Ron Blankstein
- Brigham and Women's Hospital (W.H.S., R.B.), Harvard Medical School, Boston, MA
| | - Richard K Cheng
- University of Washington School of Medicine, Seattle (L.L.V., K.K.P., R.K.C.)
| | - Maryjane A Farr
- Columbia University Irving Medical Center, New York City, NY (M.A.F.)
| | - Jerry D Estep
- Cleveland Clinic, OH (M.K.C., D.A.C., C.L.J., D.H.K., P.C.C., A.B., T.D.C., P.B., J.D.E.)
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10
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Lakkireddy DR, Chung MK, Deering TF, Gopinathannair R, Albert CM, Epstein LM, Harding CV, Hurwitz JL, Jeffery CC, Krahn AD, Kusumoto FM, Lampert R, Mansour M, Natale A, Patton KK, Seiler A, Shah MJ, Wang PJ, Russo AM. Guidance for Rebooting Electrophysiology Through the COVID-19 Pandemic From the Heart Rhythm Society and the American Heart Association Electrocardiography and Arrhythmias Committee of the Council on Clinical Cardiology: Endorsed by the American College of Cardiology. JACC Clin Electrophysiol 2020; 6:1053-1066. [PMID: 32819525 PMCID: PMC7291987 DOI: 10.1016/j.jacep.2020.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Coronavirus disease 2019 (COVID-19) has presented substantial challenges to patient care and impacted health care delivery, including cardiac electrophysiology practice throughout the globe. Based upon the undetermined course and regional variability of the pandemic, there is uncertainty as to how and when to resume and deliver electrophysiology services for arrhythmia patients. This joint document from representatives of the Heart Rhythm Society, American Heart Association, and American College of Cardiology seeks to provide guidance for clinicians and institutions reestablishing safe electrophysiological care. To achieve this aim, we address regional and local COVID-19 disease status, the role of viral screening and serologic testing, return-to-work considerations for exposed or infected health care workers, risk stratification and management strategies based on COVID-19 disease burden, institutional preparedness for resumption of elective procedures, patient preparation and communication, prioritization of procedures, and development of outpatient and periprocedural care pathways.
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Affiliation(s)
| | - Mina K Chung
- Heart, Vascular, and Thoracic Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | | | - Rakesh Gopinathannair
- Kansas City Heart Rhythm Institute and Research Foundation, Overland Park, Kansas, USA
| | - Christine M Albert
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | | | | | | | - Courtney C Jeffery
- Kansas City Heart Rhythm Institute and Research Foundation, Overland Park, Kansas, USA
| | - Andrew D Krahn
- University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | - Moussa Mansour
- Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Andrea Natale
- Texas Cardiac Arrhythmia Institute, Austin, Texas, USA
| | | | | | - Maully J Shah
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Paul J Wang
- Stanford University, Palo Alto, California, USA
| | - Andrea M Russo
- Cooper Medical School of Rowan University, Camden, New Jersey, USA
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11
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Chung MK, Karnik S, Saef J, Bergmann C, Barnard J, Lederman MM, Tilton J, Cheng F, Harding CV, Young JB, Mehta N, Cameron SJ, McCrae KR, Schmaier AH, Smith JD, Kalra A, Gebreselassie SK, Thomas G, Hawkins ES, Svensson LG. SARS-CoV-2 and ACE2: The biology and clinical data settling the ARB and ACEI controversy. EBioMedicine 2020; 58:102907. [PMID: 32771682 PMCID: PMC7415847 DOI: 10.1016/j.ebiom.2020.102907] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/20/2020] [Accepted: 07/07/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND SARS-CoV-2 enters cells by binding of its spike protein to angiotensin-converting enzyme 2 (ACE2). Angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) have been reported to increase ACE2 expression in animal models, and worse outcomes are reported in patients with co-morbidities commonly treated with these agents, leading to controversy during the COVID-19 pandemic over whether these drugs might be helpful or harmful. METHODS Animal, in vitro and clinical data relevant to the biology of the renin-angiotensin system (RAS), its interaction with the kallikrein-kinin system (KKS) and SARS-CoV-2, and clinical studies were reviewed. FINDINGS AND INTERPRETATION SARS-CoV-2 hijacks ACE2to invade and damage cells, downregulating ACE2, reducing its protective effects and exacerbating injurious Ang II effects. However, retrospective observational studies do not show higher risk of infection with ACEI or ARB use. Nevertheless, study of the RAS and KKS in the setting of coronaviral infection may yield therapeutic targets.
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Affiliation(s)
- Mina K Chung
- Heart, Vascular and Thoracic Institute, United States; Lerner Research Institute, Cleveland Clinic, United States; Cleveland Clinic Lerner College of Medicine, United States; Case Western Reserve University, United States.
| | - Sadashiva Karnik
- Lerner Research Institute, Cleveland Clinic, United States; Cleveland Clinic Lerner College of Medicine, United States; Case Western Reserve University, United States
| | - Joshua Saef
- Heart, Vascular and Thoracic Institute, United States
| | - Cornelia Bergmann
- Lerner Research Institute, Cleveland Clinic, United States; Cleveland Clinic Lerner College of Medicine, United States; Case Western Reserve University, United States
| | - John Barnard
- Lerner Research Institute, Cleveland Clinic, United States
| | - Michael M Lederman
- Case Western Reserve University, United States; University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - John Tilton
- Case Western Reserve University, United States
| | - Feixiong Cheng
- Lerner Research Institute, Cleveland Clinic, United States
| | - Clifford V Harding
- Case Western Reserve University, United States; University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - James B Young
- Heart, Vascular and Thoracic Institute, United States; Cleveland Clinic Lerner College of Medicine, United States; Case Western Reserve University, United States
| | - Neil Mehta
- Cleveland Clinic Lerner College of Medicine, United States; Case Western Reserve University, United States
| | - Scott J Cameron
- Heart, Vascular and Thoracic Institute, United States; Lerner Research Institute, Cleveland Clinic, United States; Cleveland Clinic Lerner College of Medicine, United States
| | - Keith R McCrae
- Lerner Research Institute, Cleveland Clinic, United States; Cleveland Clinic Lerner College of Medicine, United States
| | - Alvin H Schmaier
- Case Western Reserve University, United States; University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - Jonathan D Smith
- Lerner Research Institute, Cleveland Clinic, United States; Cleveland Clinic Lerner College of Medicine, United States; Case Western Reserve University, United States
| | - Ankur Kalra
- Heart, Vascular and Thoracic Institute, United States
| | - Surafel K Gebreselassie
- Cleveland Clinic Lerner College of Medicine, United States; Case Western Reserve University, United States
| | - George Thomas
- Cleveland Clinic Lerner College of Medicine, United States; Case Western Reserve University, United States
| | - Edward S Hawkins
- Cleveland Clinic Lerner College of Medicine, United States; Case Western Reserve University, United States
| | - Lars G Svensson
- Heart, Vascular and Thoracic Institute, United States; Cleveland Clinic Lerner College of Medicine, United States; Case Western Reserve University, United States
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12
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Sekulic M, Harper H, Nezami BG, Shen DL, Sekulic SP, Koeth AT, Harding CV, Gilmore H, Sadri N. Molecular Detection of SARS-CoV-2 Infection in FFPE Samples and Histopathologic Findings in Fatal SARS-CoV-2 Cases. Am J Clin Pathol 2020; 154:190-200. [PMID: 32451533 PMCID: PMC7314275 DOI: 10.1093/ajcp/aqaa091] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES To report methods and findings of 2 autopsies with molecular evaluation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive individuals. METHODS Postmortem examination was completed following Centers for Disease Control and Prevention public guidelines. Numerous formalin-fixed paraffin-embedded (FFPE) tissue types from each case were surveyed for SARS-CoV-2 RNA by quantitative reverse transcription polymerase chain reaction (qRT-PCR). SARS-CoV-2 viral genome was sequenced by next-generation sequencing (NGS) from FFPE lung tissue blocks. RESULTS Postmortem examinations revealed diffuse alveolar damage, while no viral-associated hepatic, cardiac, or renal damage was observed. Viral RNA was detected in lungs, bronchi, lymph nodes, and spleen in both cases using qRT-PCR method. RNA sequencing using NGS in case 1 revealed mutations most consistent with Western European Clade A2a with ORF1a L3606F mutation. CONCLUSIONS SARS-CoV-2 testing and viral sequencing can be performed from FFPE tissue. Detection and sequencing of SARS-CoV-2 in combination with morphological findings from postmortem tissue examination can aid in gaining a better understanding of the virus's pathophysiologic effects on human health.
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Affiliation(s)
- Miroslav Sekulic
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Holly Harper
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Behtash G Nezami
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Daniel L Shen
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Simona Pichler Sekulic
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Aaron T Koeth
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH
| | - Clifford V Harding
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Hannah Gilmore
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Navid Sadri
- Department of Pathology, University Hospitals Cleveland Medical Center, Cleveland, OH
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH
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13
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Lakkireddy DR, Chung MK, Deering TF, Gopinathannair R, Albert CM, Epstein LM, Harding CV, Hurwitz JL, Jeffery CC, Krahn AD, Kusumoto FM, Lampert R, Mansour M, Natale A, Patton KK, Seiler A, Shah MJ, Wang PJ, Russo AM. Guidance for Rebooting Electrophysiology Through the COVID-19 Pandemic From the Heart Rhythm Society and the American Heart Association Electrocardiography and Arrhythmias Committee of the Council on Clinical Cardiology. Circ Arrhythm Electrophysiol 2020; 13:e008999. [PMID: 32530306 PMCID: PMC7368851 DOI: 10.1161/circep.120.008999] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Coronavirus disease 2019 (COVID-19) has presented substantial challenges to patient care and impacted healthcare delivery, including cardiac electrophysiology practice throughout the globe. Based upon the undetermined course and regional variability of the pandemic, there is uncertainty as to how and when to resume and deliver electrophysiology services for patients with arrhythmia. This joint document from representatives of the Heart Rhythm Society, American Heart Association, and American College of Cardiology seeks to provide guidance for clinicians and institutions reestablishing safe electrophysiological care. To achieve this aim, we address regional and local COVID-19 disease status, the role of viral screening and serological testing, return-to-work considerations for exposed or infected health care workers, risk stratification and management strategies based on COVID-19 disease burden, institutional preparedness for resumption of elective procedures, patient preparation and communication, prioritization of procedures, and development of outpatient and periprocedural care pathways.
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Affiliation(s)
- Dhanunjaya R Lakkireddy
- Kansas City Heart Rhythm Institute and Research Foundation, Overland Park (D.R.L., R.G., C.C.J.)
| | - Mina K Chung
- Heart, Vascular, and Thoracic Institute and Lerner Research Institute, Cleveland Clinic, OH (M.K.C.)
| | | | - Rakesh Gopinathannair
- Kansas City Heart Rhythm Institute and Research Foundation, Overland Park (D.R.L., R.G., C.C.J.)
| | - Christine M Albert
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (C.M.A.)
| | | | | | | | - Courtney C Jeffery
- Kansas City Heart Rhythm Institute and Research Foundation, Overland Park (D.R.L., R.G., C.C.J.)
| | - Andrew D Krahn
- University of British Columbia, Vancouver, Canada (A.D.K.)
| | | | | | | | | | | | | | | | | | - Andrea M Russo
- Cooper Medical School of Rowan University, Camden, NJ (A.M.R.)
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14
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Lakkireddy DR, Chung MK, Deering TF, Gopinathannair R, Albert CM, Epstein LM, Harding CV, Hurwitz JL, Jeffery CC, Krahn AD, Kusumoto FM, Lampert R, Mansour M, Natale A, Patton KK, Seiler A, Shah MJ, Wang PJ, Russo AM. Guidance for rebooting electrophysiology through the COVID-19 pandemic from the Heart Rhythm Society and the American Heart Association Electrocardiography and Arrhythmias Committee of the Council on Clinical Cardiology: Endorsed by the American College of Cardiology. Heart Rhythm 2020; 17:e242-e254. [PMID: 32540298 PMCID: PMC7291964 DOI: 10.1016/j.hrthm.2020.06.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 06/09/2020] [Indexed: 01/12/2023]
Abstract
Coronavirus disease 2019 (COVID-19) has presented substantial challenges to patient care and impacted health care delivery, including cardiac electrophysiology practice throughout the globe. Based upon the undetermined course and regional variability of the pandemic, there is uncertainty as to how and when to resume and deliver electrophysiology services for arrhythmia patients. This joint document from representatives of the Heart Rhythm Society, American Heart Association, and American College of Cardiology seeks to provide guidance for clinicians and institutions reestablishing safe electrophysiological care. To achieve this aim, we address regional and local COVID-19 disease status, the role of viral screening and serologic testing, return-to-work considerations for exposed or infected health care workers, risk stratification and management strategies based on COVID-19 disease burden, institutional preparedness for resumption of elective procedures, patient preparation and communication, prioritization of procedures, and development of outpatient and periprocedural care pathways.
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Affiliation(s)
| | - Mina K Chung
- Heart, Vascular, and Thoracic Institute and Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | | | | | - Christine M Albert
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | | | | | | | - Courtney C Jeffery
- Kansas City Heart Rhythm Institute and Research Foundation, Overland Park, Kansas
| | - Andrew D Krahn
- University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | | | | | | | | | - Maully J Shah
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | | | - Andrea M Russo
- Cooper Medical School of Rowan University, Camden, New Jersey
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15
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Groft SG, Nagy N, Shukla S, Harding CV, Boom WH. TLR2-Tpl2-dependent ERK Signaling Drives Opposite IL-12 Regulation in Dendritic Cells and Macrophages. The Journal of Immunology 2020. [DOI: 10.4049/jimmunol.204.supp.226.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
This study investigated responses to TLR2-driven ERK signaling in dendritic cells versus macrophages. TLR2 signaling was induced with Pam3Cys, and the role of ERK signaling was interrogated pharmacologically with a MEK1/2 inhibitor (U0126) or genetically using bone-marrow-derived macrophages or dendritic cells from Tpl2−/− mice. We assessed cytokine production via ELISA and mRNA levels by qRT-PCR. In macrophages, blockade of ERK signaling by pharmacologic or genetic approaches inhibited IL-10 production and increased IL-12p40 production significantly. In dendritic cells, blockade of ERK signaling similarly inhibited IL-10 production but decreased IL-12p40 production, opposite to the effect of ERK signaling blockade in macrophages. This difference in IL-12p40 regulation correlated with differential expression of transcription factors cFos and IRF1, which are known to regulate IL-12. Thus, the impact of ERK signaling in response to TLR2 stimulation differs between macrophages and dendritic cells, potentially regulating their distinctive functions in the immune system. ERK-mediated suppression of IL-12p40 in macrophages may prevent excess inflammation and associated tissue damage following TLR2-stimuation, while ERK-mediated induction of IL-12p40 in dendritic cells may promote priming of Th1 responses. Greater understanding of the role that ERK signaling plays in different immune cell types may inform the development of host-directed therapy for a number of infectious pathogens.
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Affiliation(s)
- Sarah Grace Groft
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Nancy Nagy
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Supriya Shukla
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Clifford V Harding
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - W Henry Boom
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
- 2Division of Infectious Diseases, Case Western Reserve University, Cleveland, OH
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16
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Bashover EM, Stefaniuk CM, Harding CV, Maitta RW. Use of a whole-cell ELISA to detect additional antibodies in setting of suspected heparin-induced thrombocytopenia. Eur J Haematol 2019; 103:99-106. [PMID: 31107976 DOI: 10.1111/ejh.13263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 05/17/2019] [Indexed: 01/13/2023]
Abstract
OBJECTIVES Type II heparin-induced thrombocytopenia (HIT) is mediated by formation of antibodies to platelet factor 4 (PF4)-heparin complexes. We evaluated anti-PF4-heparin-negative samples for the presence of additional anti-platelet and anti-red blood cell (RBC) antibodies using whole-cell platelet/ RBC ELISAs we developed. METHODS Seventy-three samples tested for anti-PF4-heparin by ELISA were included: 62 tested negative, 9 tested positive, and 2 had equivocal results. Plasma specimens from healthy donors were used as controls. RESULTS 100% (9/9) anti-PF4-positive samples had anti-platelet antibodies detected by whole-cell platelet ELISA. 42.2% (27/64) anti-PF4-heparin-negative samples were negative for anti-platelet and anti-RBC antibodies. 32.8% (21/64) negative samples showed reactivity to both platelets and RBC; 12.5% (8/64) negative samples were each reactive with either platelet or RBC ELISA, respectively. Additionally, two samples that tested equivocal by anti-PF4-heparin ELISA had antibodies to both platelets and RBC by whole-cell ELISA. CONCLUSIONS Our study suggests that patients with thrombocytopenia testing negative for anti-PF4-heparin may still harbor antibodies to platelets. However, additional research is needed to determine the significance of these antibodies. Nevertheless, these findings may encourage clinicians to further investigate patients with possible immune-mediated etiologies of thrombocytopenia and anemia.
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Affiliation(s)
- Eva M Bashover
- Department of Pathology, Case Western Reserve University School of Medicine, University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | - Catherine M Stefaniuk
- Department of Pathology, Case Western Reserve University School of Medicine, University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | - Clifford V Harding
- Department of Pathology, Case Western Reserve University School of Medicine, University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | - Robert W Maitta
- Department of Pathology, Case Western Reserve University School of Medicine, University Hospitals Cleveland Medical Center, Cleveland, Ohio
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17
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Groft SG, Nagy N, Shukla S, Sweet D, Boom WH, Harding CV. Outcomes of ERK Signaling Differ in Macrophages and Dendritic Cells. The Journal of Immunology 2019. [DOI: 10.4049/jimmunol.202.supp.64.24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Stimulation of dendritic cells and macrophages by pathogen-related products activates a variety of immune responses. Pathogen-induced cell signaling and associated outcome research is abundant in macrophages, but minimal in dendritic cells. We investigated the role of ERK signaling in the induction of cytokines such as IL-12p40 and IL-10 following activation by Pam3Cys or Mycobacterium tuberculosis (Mtb) H37Ra. ERK ablation was accomplished pharmacologically with MERK1/2 inhibitor U0126 or genetically by using cells from Tpl2−/− mice (TPL2 connects TLR to ERK). We utilized western blotting to examine ERK activation, ELISA to assess cytokine production, and qRT-PCR to investigate mRNA levels. In macrophages, blockade of ERK signaling inhibited IL-10 production and increased IL-12p40 production (6–10 fold increase in IL-12p40 mRNA and 3–4 fold increase in protein). In dendritic cells, ERK blockade similarly inhibited IL-10 production, but produced a very different change in IL-12p40 expression: ERK blockade decreased IL-12p40 production (2-fold decrease in IL-12p40 mRNA and protein). This result suggests that the impact of ERK signaling in response to these stimuli differs between macrophages and dendritic cells for a subset of ERK-regulated genes. ERK-mediated suppression of IL-12p40 in macrophages may prevent excess inflammation and associated tissue damage, while ERK-mediated induction of IL-12p40 in dendritic cells may promote priming of Th1 responses. Future studies will examine other genes and proteins involved in infection responses. Greater understanding of the role that ERK signaling plays in different cell types may inform the development of host-directed therapy for infections such as tuberculosis.
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Affiliation(s)
- Sarah Grace Groft
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Nancy Nagy
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Supriya Shukla
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - David Sweet
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - W Henry Boom
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
- 2Division of Infectious Diseases, Case Western Reserve University, Cleveland, OH
| | - Clifford V Harding
- 1Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio
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18
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Chen L, Feng Z, Yue H, Bazdar D, Mbonye U, Zender C, Harding CV, Bruggeman L, Karn J, Sieg SF, Wang B, Jin G. Exosomes derived from HIV-1-infected cells promote growth and progression of cancer via HIV TAR RNA. Nat Commun 2018; 9:4585. [PMID: 30389917 PMCID: PMC6214989 DOI: 10.1038/s41467-018-07006-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 10/08/2018] [Indexed: 12/17/2022] Open
Abstract
People living with HIV/AIDS on antiretroviral therapy have increased risk of non-AIDS-defining cancers (NADCs). However, the underlying mechanism for development and progression of certain NADCs remains obscure. Here we show that exosomes released from HIV-infected T cells and those purified from blood of HIV-positive patients stimulate proliferation, migration and invasion of oral/oropharyngeal and lung cancer cells. The HIV transactivation response (TAR) element RNA in HIV-infected T-cell exosomes is responsible for promoting cancer cell proliferation and inducing expression of proto-oncogenes and Toll-like receptor 3 (TLR3)-inducible genes. These effects depend on the loop/bulge region of the molecule. HIV-infected T-cell exosomes rapidly enter recipient cells through epidermal growth factor receptor (EGFR) and stimulate ERK1/2 phosphorylation via the EGFR/TLR3 axis. Thus, our findings indicate that TAR RNA-containing exosomes from HIV-infected T cells promote growth and progression of particular NADCs through activation of the ERK cascade in an EGFR/TLR3-dependent manner. HIV patients have an increased risk of developing non-AIDS-defining cancers but the molecular mechanisms underlying this predisposition are unclear. Here the authors show that exosomes secreted by HIV-infected T cells or isolated from the blood of HIV-positive patients, stimulate oncogenic properties of cancer cells through the activation of ERK1/2 signaling pathway.
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Affiliation(s)
- Lechuang Chen
- Department of Biological Sciences, Case Western Reserve University School of Dental Medicine, Cleveland, OH, 44106, USA
| | - Zhimin Feng
- Department of Biological Sciences, Case Western Reserve University School of Dental Medicine, Cleveland, OH, 44106, USA
| | - Hong Yue
- Department of Biological Sciences, Case Western Reserve University School of Dental Medicine, Cleveland, OH, 44106, USA.,Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, 25701, USA
| | - Douglas Bazdar
- Department of Medicine, Division of Infectious Diseases and HIV Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Uri Mbonye
- Department of Molecular Biology & Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Chad Zender
- Department of Otolaryngology/ENT Institute, Case Western Reserve University School of Medicine and University Hospitals Cleveland Medical Center, Cleveland, OH, 44106, USA.,Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Clifford V Harding
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA.,Department of Pathology, Case Western Reserve University School of Medicine and University Hospitals Cleveland Medical Center, Cleveland, OH, 44106, USA.,Center for AIDS Research, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, OH, 44106, USA
| | - Leslie Bruggeman
- Center for AIDS Research, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, OH, 44106, USA.,Department of Inflammation and Immunity, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, 44195, USA
| | - Jonathan Karn
- Department of Molecular Biology & Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.,Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA.,Center for AIDS Research, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, OH, 44106, USA
| | - Scott F Sieg
- Department of Medicine, Division of Infectious Diseases and HIV Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.,Center for AIDS Research, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, OH, 44106, USA
| | - Bingcheng Wang
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA.,Department of Medicine, Pharmacology and Oncology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Ge Jin
- Department of Biological Sciences, Case Western Reserve University School of Dental Medicine, Cleveland, OH, 44106, USA. .,Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, 44106, USA. .,Center for AIDS Research, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, OH, 44106, USA.
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19
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Stefaniuk CM, Hong H, Harding CV, Maitta RW. α-Synuclein concentration increases over time in plasma supernatant of single donor platelets. Eur J Haematol 2018; 101:10.1111/ejh.13152. [PMID: 30055066 PMCID: PMC6349522 DOI: 10.1111/ejh.13152] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 07/24/2018] [Indexed: 01/09/2023]
Abstract
OBJECTIVES In platelets, α-synuclein is important in calcium-dependent granule release. Notably, cells release α-synuclein in setting of cell damage or death. Therefore, we investigated α-synuclein levels in plasma of single donor platelet (SDP) units during storage. METHODS Aliquots were obtained from same SDP units for 7 days from day of donation. Additionally, randomly sampled SDP units at same storage time points were also assayed by enzyme-linked immunosorbent assay. RESULTS α-Synuclein in SDP plasma increased continuously over time at each assayed time point. Significant increases were measured on day 3 (11.7 ± 9.6 ng/mL, P = 0.025), day 5 (15.3 ± 5.9 ng/mL, P = 0.002), and highest on day 7 (23.7 ± 5.6 ng/mL, P < 0.0001) compared to day 0 (1.1 ± 0.8 ng/mL). Similar significant results were obtained in randomly sampled SDP units at same corresponding time points. Flow cytometry showed that platelets had strong expression of α-synuclein and lacked expression of other synucleins. CONCLUSIONS Increases of α-synuclein during SDP storage is a steady and continuous process that increases with time. Our findings indicate that α-synuclein may represent a biomarker of platelet biological state during storage. Further research will be needed to determine how α-synuclein increases correlate with platelets' function.
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Affiliation(s)
- Catherine M. Stefaniuk
- University Hospitals Cleveland Medical Center and Case Western Reserve University School of Medicine, Cleveland, OH
| | - Hong Hong
- University Hospitals Cleveland Medical Center and Case Western Reserve University School of Medicine, Cleveland, OH
| | - Clifford V. Harding
- University Hospitals Cleveland Medical Center and Case Western Reserve University School of Medicine, Cleveland, OH
| | - Robert W. Maitta
- University Hospitals Cleveland Medical Center and Case Western Reserve University School of Medicine, Cleveland, OH
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20
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Harding CV, Akabas MH, Andersen OS. In Reply to Sun et al. Acad Med 2018; 93:150-151. [PMID: 29377855 DOI: 10.1097/acm.0000000000002036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Clifford V Harding
- Joseph R. Kahn Professor, chair of pathology, and director, Medical Scientist Training Program, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio; e-mail: ; ORCID: http://orcid.org/0000-0002-6333-162X. Professor of physiology and biophysics and director, Medical Scientist Training Program, Albert Einstein College of Medicine, Bronx, New York; ORCID: http://orcid.org/0000-0001-8781-7846. Professor of physiology and biophysics, Weill Cornell Medical College, and director, Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, New York; ORCID: http://orcid.org/0000-0002-3026-6710
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21
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Karim AF, Sande OJ, Tomechko SE, Ding X, Li M, Maxwell S, Ewing RM, Harding CV, Rojas RE, Chance MR, Boom WH. Proteomics and Network Analyses Reveal Inhibition of Akt-mTOR Signaling in CD4 + T Cells by Mycobacterium tuberculosis Mannose-Capped Lipoarabinomannan. Proteomics 2017; 17:1700233. [PMID: 28994205 PMCID: PMC5725663 DOI: 10.1002/pmic.201700233] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 09/13/2017] [Indexed: 11/10/2022]
Abstract
Mycobacterium tuberculosis (Mtb) cell wall glycolipid mannose-capped lipoarabinomannan (ManLAM) inhibits CD4+ T-cell activation by inhibiting proximal T-cell receptor (TCR) signaling when activated by anti-CD3. To understand the impact of ManLAM on CD4+ T-cell function when both the TCR-CD3 complex and major costimulator CD28 are engaged, we performed label-free quantitative MS and network analysis. Mixed-effect model analysis of peptide intensity identified 149 unique peptides representing 131 proteins that were differentially regulated by ManLAM in anti-CD3- and anti-CD28-activated CD4+ T cells. Crosstalker, a novel network analysis tool identified dysregulated translation, TCA cycle, and RNA metabolism network modules. PCNA, Akt, mTOR, and UBC were found to be bridge node proteins connecting these modules of dysregulated proteins. Altered PCNA expression and cell cycle analysis showed arrest at the G2M phase. Western blot confirmed that ManLAM inhibited Akt and mTOR phosphorylation, and decreased expression of deubiquitinating enzymes Usp9x and Otub1. Decreased NF-κB phosphorylation suggested interference with CD28 signaling through inhibition of the Usp9x-Akt-mTOR pathway. Thus, ManLAM induced global changes in the CD4+ T-cell proteome by affecting Akt-mTOR signaling, resulting in broad functional impairment of CD4+ T-cell activation beyond inhibition of proximal TCR-CD3 signaling.
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Affiliation(s)
- Ahmad F. Karim
- Department of MedicineUniversity Hospitals Cleveland Medical CenterCase Western Reserve UniversityClevelandOHUSA
- Department of Molecular Biology & MicrobiologyCase Western Reserve UniversityClevelandOHUSA
| | - Obondo J. Sande
- Department of MedicineUniversity Hospitals Cleveland Medical CenterCase Western Reserve UniversityClevelandOHUSA
| | - Sara E. Tomechko
- Center for Proteomics & BioinformaticsCase Western Reserve UniversityClevelandOHUSA
| | - Xuedong Ding
- Department of MedicineUniversity Hospitals Cleveland Medical CenterCase Western Reserve UniversityClevelandOHUSA
| | - Ming Li
- Center for Proteomics & BioinformaticsCase Western Reserve UniversityClevelandOHUSA
| | - Sean Maxwell
- Center for Proteomics & BioinformaticsCase Western Reserve UniversityClevelandOHUSA
| | - Rob M. Ewing
- Centre for Biological SciencesUniversity of SouthamptonSouthamptonUK
| | - Clifford V. Harding
- Department of Molecular Biology & MicrobiologyCase Western Reserve UniversityClevelandOHUSA
- Department of PathologyUniversity Hospitals Cleveland Medical CenterCase Western Reserve UniversityClevelandOHUSA
| | - Roxana E. Rojas
- Department of Molecular Biology & MicrobiologyCase Western Reserve UniversityClevelandOHUSA
| | - Mark R. Chance
- Center for Proteomics & BioinformaticsCase Western Reserve UniversityClevelandOHUSA
- Department of NutritionSchool of MedicineCase Western Reserve UniversityClevelandOHUSA
| | - W. Henry Boom
- Department of MedicineUniversity Hospitals Cleveland Medical CenterCase Western Reserve UniversityClevelandOHUSA
- Department of Molecular Biology & MicrobiologyCase Western Reserve UniversityClevelandOHUSA
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22
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Abstract
Physician-scientists are needed to continue the great pace of recent biomedical research and translate scientific findings to clinical applications. MD-PhD programs represent one approach to train physician-scientists. MD-PhD training started in the 1950s and expanded greatly with the Medical Scientist Training Program (MSTP), launched in 1964 by the National Institute of General Medical Sciences (NIGMS) at the National Institutes of Health. MD-PhD training has been influenced by substantial changes in medical education, science, and clinical fields since its inception. In 2014, NIGMS held a 50th Anniversary MSTP Symposium highlighting the program and assessing its outcomes. In 2016, there were over 90 active MD-PhD programs in the United States, of which 45 were MSTP supported, with a total of 988 trainee slots. Over 10,000 students have received MSTP support since 1964. The authors present data for the demographic characteristics and outcomes for 9,683 MSTP trainees from 1975-2014. The integration of MD and PhD training has allowed trainees to develop a rigorous foundation in research in concert with clinical training. MSTP graduates have had relative success in obtaining research grants and have become prominent leaders in many biomedical research fields. Many challenges remain, however, including the need to maintain rigorous scientific components in evolving medical curricula, to enhance research-oriented residency and fellowship opportunities in a widening scope of fields targeted by MSTP graduates, to achieve greater racial diversity and gender balance in the physician-scientist workforce, and to sustain subsequent research activities of physician-scientists.
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Affiliation(s)
- Clifford V Harding
- C.V. Harding is Joseph R. Kahn Professor, chair of pathology, and director, Medical Scientist Training Program, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio. M.H. Akabas is professor of physiology and biophysics, and director, Medical Scientist Training Program, Albert Einstein College of Medicine, Bronx, New York. O.S. Andersen is professor of physiology and biophysics, Weill Cornell Medical College, and director, Weill Cornell/Rockefeller/Sloan Kettering Tri-institutional MD-PhD Program, New York, New York
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23
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Mazahery C, Chirieleison S, Shukla S, Onwuzulike S, Jain M, Boom WH, Abbott DW, Harding CV. Macrophage Krüppel-like factor 4 regulates response to Mycobacterium tuberculosis infection. The Journal of Immunology 2017. [DOI: 10.4049/jimmunol.198.supp.148.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Krüppel-like factor 4 (KLF4) is a transcription factor that polarizes macrophages towards an anti-inflammatory (M2) phenotype, which suggests that it may regulate immune responses to Mycobacterium tuberculosis (Mtb), as immune evasion by Mtb may be due to an overabundance of anti-inflammatory mediators in response to infection. We hypothesize that myeloid KLF4 is permissive of immune evasion by Mtb, causing decreased control of Mtb infection. There are no prior in vivo data on the role of KLF4 in infection. Using mice with myeloid-specific knockout of KLF4 (LysMCre/CreKLF4fl/fl, abbreviated Mye-KO) we observed decreased Mtb CFU in macrophage cultures in vitro and in lungs of Mye-KO mice early in infection (day 14) relative to wild-type controls. However, these experiments also revealed complexities to the KLF4-Mtb relationship. Despite their improved control of early infection, at later time points Mye-KO mice developed worsened clinical disease features, such as wasting, which suggests that the loss of KLF4 results in pathologic immune state. In addition, we found discrepancy between KLF4 RNA and protein expression during Mtb infection, suggesting that KLF4 is regulated at a posttranslational level during infection. We are designing an in vitro system in which to study the molecular mechanisms of KLF4 regulation and activity in macrophages. Our data indicate that KLF4 plays an important role is regulating immune responses to Mtb with the potential to both diminish host defense mechanisms and repress host-damaging immune mechanisms.
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24
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Athman JJ, Sande OJ, Groft SG, Reba SM, Nagy N, Wearsch PA, Richardson ET, Rojas R, Boom WH, Shukla S, Harding CV. Mycobacterium tuberculosis Membrane Vesicles Inhibit T Cell Activation. J Immunol 2017; 198:2028-2037. [PMID: 28122965 DOI: 10.4049/jimmunol.1601199] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 12/22/2016] [Indexed: 12/31/2022]
Abstract
Mycobacterium tuberculosis utilizes multiple mechanisms to evade host immune responses, and inhibition of effector CD4+ T cell responses by M. tuberculosis may contribute to immune evasion. TCR signaling is inhibited by M. tuberculosis cell envelope lipoglycans, such as lipoarabinomannan and lipomannan, but a mechanism for lipoglycans to traffic from M. tuberculosis within infected macrophages to reach T cells is unknown. In these studies, we found that membrane vesicles produced by M. tuberculosis and released from infected macrophages inhibited the activation of CD4+ T cells, as indicated by reduced production of IL-2 and reduced T cell proliferation. Flow cytometry and Western blot demonstrated that lipoglycans from M. tuberculosis-derived bacterial vesicles (BVs) are transferred to T cells, where they inhibit T cell responses. Stimulation of CD4+ T cells in the presence of BVs induced expression of GRAIL, a marker of T cell anergy; upon restimulation, these T cells showed reduced ability to proliferate, confirming a state of T cell anergy. Furthermore, lipoarabinomannan was associated with T cells after their incubation with infected macrophages in vitro and when T cells were isolated from lungs of M. tuberculosis-infected mice, confirming the occurrence of lipoarabinomannan trafficking to T cells in vivo. These studies demonstrate a novel mechanism for the direct regulation of CD4+ T cells by M. tuberculosis lipoglycans conveyed by BVs that are produced by M. tuberculosis and released from infected macrophages. These lipoglycans are transferred to T cells to inhibit T cell responses, providing a mechanism that may promote immune evasion.
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Affiliation(s)
- Jaffre J Athman
- Department of Pathology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106
| | - Obondo J Sande
- Department of Pathology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106.,Department of Molecular Biology and Microbiology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106
| | - Sarah G Groft
- Department of Pathology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106
| | - Scott M Reba
- Department of Molecular Biology and Microbiology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106
| | - Nancy Nagy
- Department of Pathology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106
| | - Pamela A Wearsch
- Department of Pathology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106
| | - Edward T Richardson
- Department of Pathology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106.,Medical Scientist Training Program, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106
| | - Roxana Rojas
- Department of Molecular Biology and Microbiology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106.,Center for AIDS Research, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106; and
| | - W Henry Boom
- Department of Molecular Biology and Microbiology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106.,Center for AIDS Research, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106; and.,Division of Infectious Diseases and HIV Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106
| | - Supriya Shukla
- Department of Pathology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106
| | - Clifford V Harding
- Department of Pathology, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106; .,Center for AIDS Research, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106; and.,Division of Infectious Diseases and HIV Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, OH 44106
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25
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Abstract
Exosomes and other extracellular microvesicles (ExMVs) have important functions in intercellular communication and regulation. During the course of infection, these vesicles can convey pathogen molecules that serve as antigens or agonists of innate immune receptors to induce host defense and immunity, or that serve as regulators of host defense and mediators of immune evasion. These molecules may include proteins, nucleic acids, lipids, and carbohydrates. Pathogen molecules may be disseminated by incorporation into vesicles that are created and shed by host cells, or they may be incorporated into vesicles shed from microbial cells. Involvement of ExMVs in the induction of immunity and host defense is widespread among many pathogens, whereas their involvement in immune evasion mechanisms is prominent among pathogens that establish chronic infection and is found in some that cause acute infection. Because of their immunogenicity and enrichment of pathogen molecules, exosomes may also have potential in vaccine preparations and as diagnostic markers. Additionally, the ability of exosomes to deliver molecules to recipient cells raises the possibility of their use for drug/therapy delivery. Thus, ExMVs play a major role in the pathogenesis of infection and provide exciting potential for the development of novel diagnostic and therapeutic approaches.
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26
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Sande OJ, Karim AF, Li Q, Ding X, Harding CV, Rojas RE, Boom WH. Mannose-Capped Lipoarabinomannan from Mycobacterium tuberculosis Induces CD4+ T Cell Anergy via GRAIL. J Immunol 2015; 196:691-702. [PMID: 26667170 DOI: 10.4049/jimmunol.1500710] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 11/06/2015] [Indexed: 01/20/2023]
Abstract
Mycobacterium tuberculosis cell wall glycolipid, lipoarabinomannan, can inhibit CD4(+) T cell activation by downregulating the phosphorylation of key proximal TCR signaling molecules: Lck, CD3ζ, ZAP70, and LAT. Inhibition of proximal TCR signaling can result in T cell anergy, in which T cells are inactivated following an Ag encounter, yet remain viable and hyporesponsive. We tested whether mannose-capped lipoarabinomannan (LAM)-induced inhibition of CD4(+) T cell activation resulted in CD4(+) T cell anergy. The presence of LAM during primary stimulation of P25 TCR-transgenic murine CD4(+) T cells with M. tuberculosis Ag85B peptide resulted in decreased proliferation and IL-2 production. P25 TCR-transgenic CD4(+) T cells primed in the presence of LAM also exhibited decreased response upon restimulation with Ag85B. The T cell anergic state persisted after the removal of LAM. Hyporesponsiveness to restimulation was not due to apoptosis, generation of Foxp3-positive regulatory T cells, or inhibitory cytokines. Acquisition of the anergic phenotype correlated with upregulation of gene related to anergy in lymphocytes (GRAIL) protein in CD4(+) T cells. Inhibition of human CD4(+) T cell activation by LAM also was associated with increased GRAIL expression. Small interfering RNA-mediated knockdown of GRAIL before LAM treatment abrogated LAM-induced hyporesponsiveness. In addition, exogenous IL-2 reversed defective proliferation by downregulating GRAIL expression. These results demonstrate that LAM upregulates GRAIL to induce anergy in Ag-reactive CD4(+) T cells. Induction of CD4(+) T cell anergy by LAM may represent one mechanism by which M. tuberculosis evades T cell recognition.
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Affiliation(s)
- Obondo J Sande
- Tuberculosis Research Unit, Department of Medicine, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, OH 44106; Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH 44106; and Department of Pathology, Case Western Reserve University, Cleveland, OH 44106
| | - Ahmad F Karim
- Tuberculosis Research Unit, Department of Medicine, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, OH 44106; Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH 44106; and
| | - Qing Li
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH 44106; and
| | - Xuedong Ding
- Tuberculosis Research Unit, Department of Medicine, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, OH 44106; Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH 44106; and
| | - Clifford V Harding
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106
| | - Roxana E Rojas
- Tuberculosis Research Unit, Department of Medicine, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, OH 44106; Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH 44106; and
| | - W Henry Boom
- Tuberculosis Research Unit, Department of Medicine, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, OH 44106; Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH 44106; and Department of Pathology, Case Western Reserve University, Cleveland, OH 44106
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27
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Richardson ET, Shukla S, Nagy N, Boom WH, Beck RC, Zhou L, Landreth GE, Harding CV. ERK Signaling Is Essential for Macrophage Development. PLoS One 2015; 10:e0140064. [PMID: 26445168 PMCID: PMC4596867 DOI: 10.1371/journal.pone.0140064] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 09/20/2015] [Indexed: 11/25/2022] Open
Abstract
Macrophages depend on colony stimulating factor 1 (also known as M-CSF) for their growth and differentiation, but the requirements for intracellular signals that lead to macrophage differentiation and function remain unclear. M-CSF is known to activate ERK1 and ERK2, but the importance of this signaling pathway in macrophage development is unknown. In these studies, we characterized a novel model of Erk1-/-Erk2flox/floxLyz2Cre/Cre mice in which the ERK2 isoform is deleted from macrophages in the background of global ERK1 deficiency. Cultures of M-CSF-stimulated bone marrow precursors from these mice yielded reduced numbers of macrophages. Whereas macrophages developing from M-CSF-stimulated bone marrow of Erk2flox/floxLyz2Cre/Cre mice showed essentially complete loss of ERK2 expression, the reduced number of macrophages that develop from Erk1-/-Erk2flox/floxLyz2Cre/Cre bone marrow show retention of ERK2 expression, indicating selective outgrowth of a small proportion of precursors in which Cre-mediated deletion failed to occur. The bone marrow of Erk1-/-Erk2flox/floxLyz2Cre/Cre mice was enriched for CD11b+ myeloid cells, CD11bhi Gr-1hi neutrophils, Lin- c-Kit+ Sca–1+ hematopoietic stem cells, and Lin- c-Kit+ CD34+ CD16/32+ granulocyte-macrophage progenitors. Culture of bone marrow Lin- cells under myeloid-stimulating conditions yielded reduced numbers of monocytes. Collectively, these data indicate that the defect in production of macrophages is not due to a reduced number of progenitors, but rather due to reduced ability of progenitors to proliferate and produce macrophages in response to M-CSF-triggered ERK signaling. Macrophages from Erk1-/-Erk2flox/floxLyz2Cre/Cre bone marrow showed reduced induction of M-CSF-regulated genes that depend on the ERK pathway for their expression. These data demonstrate that ERK1/ERK2 play a critical role in driving M-CSF-dependent proliferation of bone marrow progenitors for production of macrophages.
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Affiliation(s)
- Edward T. Richardson
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Medical Scientist Training Program, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Supriya Shukla
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Nancy Nagy
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - W. Henry Boom
- Division of Infectious Diseases and HIV Medicine, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Rose C. Beck
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Lan Zhou
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Gary E. Landreth
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Clifford V. Harding
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Division of Infectious Diseases and HIV Medicine, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- * E-mail:
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28
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Athman JJ, Wang Y, McDonald DJ, Boom WH, Harding CV, Wearsch PA. Bacterial Membrane Vesicles Mediate the Release of Mycobacterium tuberculosis Lipoglycans and Lipoproteins from Infected Macrophages. J Immunol 2015; 195:1044-53. [PMID: 26109643 DOI: 10.4049/jimmunol.1402894] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 05/24/2015] [Indexed: 12/21/2022]
Abstract
Mycobacterium tuberculosis is an intracellular pathogen that infects lung macrophages and releases microbial factors that regulate host defense. M. tuberculosis lipoproteins and lipoglycans block phagosome maturation, inhibit class II MHC Ag presentation, and modulate TLR2-dependent cytokine production, but the mechanisms for their release during infection are poorly defined. Furthermore, these molecules are thought to be incorporated into host membranes and released from infected macrophages within exosomes, 40-150-nm extracellular vesicles that derive from multivesicular endosomes. However, our studies revealed that extracellular vesicles released from infected macrophages include two distinct, largely nonoverlapping populations: one containing host cell markers of exosomes (CD9, CD63) and the other containing M. tuberculosis molecules (lipoglycans, lipoproteins). These vesicle populations are similar in size but have distinct densities, as determined by separation on sucrose gradients. Release of lipoglycans and lipoproteins from infected macrophages was dependent on bacterial viability, implicating active bacterial mechanisms in their secretion. Consistent with recent reports of extracellular vesicle production by bacteria (including M. tuberculosis), we propose that bacterial membrane vesicles are secreted by M. tuberculosis within infected macrophages and subsequently are released into the extracellular environment. Furthermore, extracellular vesicles released from M. tuberculosis-infected cells activate TLR2 and induce cytokine responses by uninfected macrophages. We demonstrate that these activities derive from the bacterial membrane vesicles rather than exosomes. Our findings suggest that bacterial membrane vesicles are the primary means by which M. tuberculosis exports lipoglycans and lipoproteins to impair effector functions of infected macrophages and circulate bacterial components beyond the site of infection to regulate immune responses by uninfected cells.
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Affiliation(s)
- Jaffre J Athman
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH
| | - Ying Wang
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH
| | - David J McDonald
- Department of Molecular Biology and Microbiology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH; Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH; and
| | - W Henry Boom
- Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH; and Division of Infectious Diseases, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH
| | - Clifford V Harding
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH; Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH; and
| | - Pamela A Wearsch
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH; Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH; and
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Nguyen TP, Bazdar DA, Mudd JC, Lederman MM, Harding CV, Hardy GA, Sieg SF. Interferon-α inhibits CD4 T cell responses to interleukin-7 and interleukin-2 and selectively interferes with Akt signaling. J Leukoc Biol 2015; 97:1139-46. [PMID: 25784743 DOI: 10.1189/jlb.4a0714-345rr] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 02/21/2015] [Indexed: 11/24/2022] Open
Abstract
Persistent type I IFN production occurs during chronic viral infections, such as HIV disease. As type I IFNs have antiproliferative activity, it is possible that chronic exposure to these cytokines could adversely affect T cell homeostasis. We investigated the capacity of IFN-α to impair T cell proliferation induced by the homeostatic cytokine, IL-7, or another common γ-chain cytokine, IL-2, in cells from healthy human donors. We found that IL-7- or IL-2-induced proliferation of CD4(+) T cells was partially inhibited in the presence of IFN-α. The CD4(+) T cells that were exposed to IFN-α also displayed attenuated induction of IL-2 and CD40L following TCR stimulation. Analyses of signaling pathways indicated that IL-7 and IL-2 induced a delayed and sustained P-Akt signal that lasted for several days and was partially inhibited by IFN-α. In contrast, IL-7-induced P-STAT5 was not affected by IFN-α. Furthermore, IFN-α had no detectable effect on P-Akt that was induced by the chemokine SDF-1. Both inhibitors of P-Akt and P-STAT5 blocked IL-7-induced T cell proliferation, confirming that both signaling pathways are important for IL-7-induced T cell proliferation. These results demonstrate that IFN-α can selectively inhibit cytokine-induced P-Akt as a potential mechanism to disrupt homeostasis of T lymphocytes.
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Affiliation(s)
- Thao P Nguyen
- Departments of *Medicine, Division of Infectious Diseases and HIV Medicine, and Pathology, Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Doug A Bazdar
- Departments of *Medicine, Division of Infectious Diseases and HIV Medicine, and Pathology, Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Joseph C Mudd
- Departments of *Medicine, Division of Infectious Diseases and HIV Medicine, and Pathology, Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Michael M Lederman
- Departments of *Medicine, Division of Infectious Diseases and HIV Medicine, and Pathology, Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Clifford V Harding
- Departments of *Medicine, Division of Infectious Diseases and HIV Medicine, and Pathology, Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Gareth A Hardy
- Departments of *Medicine, Division of Infectious Diseases and HIV Medicine, and Pathology, Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Scott F Sieg
- Departments of *Medicine, Division of Infectious Diseases and HIV Medicine, and Pathology, Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
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Shukla S, Richardson ET, Athman JJ, Shi L, Wearsch PA, McDonald D, Banaei N, Boom WH, Jackson M, Harding CV. Mycobacterium tuberculosis lipoprotein LprG binds lipoarabinomannan and determines its cell envelope localization to control phagolysosomal fusion. PLoS Pathog 2014; 10:e1004471. [PMID: 25356793 PMCID: PMC4214796 DOI: 10.1371/journal.ppat.1004471] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 09/14/2014] [Indexed: 01/17/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) virulence is decreased by genetic deletion of the lipoprotein LprG, but the function of LprG remains unclear. We report that LprG expressed in Mtb binds to lipoglycans, such as lipoarabinomannan (LAM), that mediate Mtb immune evasion. Lipoglycan binding to LprG was dependent on both insertion of lipoglycan acyl chains into a hydrophobic pocket on LprG and a novel contribution of lipoglycan polysaccharide components outside of this pocket. An lprG null mutant (Mtb ΔlprG) had lower levels of surface-exposed LAM, revealing a novel role for LprG in determining the distribution of components in the Mtb cell envelope. Furthermore, this mutant failed to inhibit phagosome-lysosome fusion, an immune evasion strategy mediated by LAM. We propose that LprG binding to LAM facilitates its transfer from the plasma membrane into the cell envelope, increasing surface-exposed LAM, enhancing cell envelope integrity, allowing inhibition of phagosome-lysosome fusion and enhancing Mtb survival in macrophages. The causative agent of tuberculosis, Mycobacterium tuberculosis (Mtb), persists in phagosomes inside infected macrophages. Mtb expresses lipoarabinomannan (LAM), which inhibits fusion of phagosomes with lysosomes as a means for Mtb to evade host defense. LAM is present in the cell envelope, which surrounds Mtb and interfaces with the host, but its localization remains unclear. We show that LprG, an Mtb lipoprotein, binds LAM and controls its distribution in the cell envelope. A mutant strain of Mtb that lacks LprG has less LAM at the surface of the cell envelope. This decreases LAM-mediated inhibition of phagosome-lysosome fusion, thereby impairing an immune evasion mechanism. We propose that LprG facilitates transfer of LAM from the plasma membrane into the cell envelope, enhancing its interaction with the host and ability to regulate host defense. Our results reveal mechanisms that determine bacterial cell envelope function and influence host-pathogen interactions and pathogen evasion of host defense.
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Affiliation(s)
- Supriya Shukla
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Edward T. Richardson
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Jaffre J. Athman
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Libin Shi
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Pamela A. Wearsch
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - David McDonald
- Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Department of Molecular Biology and Microbiology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Niaz Banaei
- Department of Pathology, Stanford University School of Medicine, Palo Alto, California, United States of America
| | - W. Henry Boom
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Division of Infectious Diseases, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Mary Jackson
- Department of Pathology, Stanford University School of Medicine, Palo Alto, California, United States of America
| | - Clifford V. Harding
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Division of Infectious Diseases, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- * E-mail:
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31
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Xiao W, Shameli A, Harding CV, Meyerson HJ, Maitta RW. Late stages of hematopoiesis and B cell lymphopoiesis are regulated by α-synuclein, a key player in Parkinson's disease. Immunobiology 2014; 219:836-44. [PMID: 25092570 DOI: 10.1016/j.imbio.2014.07.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 06/26/2014] [Accepted: 07/15/2014] [Indexed: 11/16/2022]
Abstract
α-Synuclein plays a crucial role in Parkinson's disease and dementias defined as synucleinopathies. α-Synuclein is expressed in hematopoietic and immune cells, but its functions in hematopoiesis and immune responses are unknown. We utilized α-synuclein(-/-) (KO) mice to investigate its role in hematopoiesis and B cell lymphopoiesis. We demonstrated hematologic abnormalities including mild anemia, smaller platelets, lymphopenia but relatively normal early hematopoiesis in KO mice compared to wild-type (WT) as measured in hematopoietic stem cells and progenitors of the different cell lineages. However, the absolute number of B220(+)IgM(+) B cells in bone marrow was reduced by 4-fold in KO mice (WT: 104±23×10(5) vs. KO: 27±5×10(5)). B cells were also reduced in KO spleens associated with effacement of splenic and lymph node architecture. KO mice showed reduced total serum IgG but no abnormality in serum IgM was noted. When KO mice were challenged with a T cell-dependent antigen, production of antigen specific IgG1 and IgG2b was abolished, but antigen specific IgM was not different from WT mice. Our study shows hematologic abnormalities including anemia and smaller platelets, reduced B cell lymphopoiesis and defects in IgG production in the absence of α-synuclein. This is the first report to show an important role of α-synuclein late in hematopoiesis, B cell lymphopoiesis and adaptive immune response.
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Affiliation(s)
- Wenbin Xiao
- Department of Pathology, University Hospitals Case Medical Center, Cleveland, OH, United States; Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Afshin Shameli
- Department of Pathology, University Hospitals Case Medical Center, Cleveland, OH, United States; Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Clifford V Harding
- Department of Pathology, University Hospitals Case Medical Center, Cleveland, OH, United States; Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Howard J Meyerson
- Department of Pathology, University Hospitals Case Medical Center, Cleveland, OH, United States; Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Robert W Maitta
- Department of Pathology, University Hospitals Case Medical Center, Cleveland, OH, United States; Case Western Reserve University School of Medicine, Cleveland, OH, United States.
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Reba SM, Li Q, Onwuzulike S, Ding X, Karim AF, Hernandez Y, Fulton SA, Harding CV, Lancioni CL, Nagy N, Rodriguez ME, Wearsch PA, Rojas RE. TLR2 engagement on CD4(+) T cells enhances effector functions and protective responses to Mycobacterium tuberculosis. Eur J Immunol 2014; 44:1410-21. [PMID: 24497180 PMCID: PMC4112943 DOI: 10.1002/eji.201344100] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 12/19/2013] [Accepted: 01/31/2014] [Indexed: 11/08/2022]
Abstract
We have previously demonstrated that mycobacterial lipoproteins engage TLR2 on human CD4(+) T cells and upregulate TCR-triggered IFN-γ secretion and cell proliferation in vitro. Here we examined the role of CD4(+) T-cell-expressed TLR2 in Mycobacterium tuberculosis (MTB) Ag-specific T-cell priming and in protection against MTB infection in vivo. Like their human counterparts, mouse CD4(+) T cells express TLR2 and respond to TLR2 costimulation in vitro. This Th1-like response was observed in the context of both polyclonal and Ag-specific TCR stimulation. To evaluate the role of T-cell TLR2 in priming of CD4(+) T cells in vivo, naive MTB Ag85B-specific TCR transgenic CD4(+) T cells (P25 TCR-Tg) were adoptively transferred into Tlr2(-/-) recipient C57BL/6 mice that were then immunized with Ag85B and with or without TLR2 ligand Pam3 Cys-SKKKK. TLR2 engagement during priming resulted in increased numbers of IFN-γ-secreting P25 TCR-Tg T cells 1 week after immunization. P25 TCR-Tg T cells stimulated in vitro via TCR and TLR2 conferred more protection than T cells stimulated via TCR alone when adoptively transferred before MTB infection. Our findings indicate that TLR2 engagement on CD4(+) T cells increases MTB Ag-specific responses and may contribute to protection against MTB infection.
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Affiliation(s)
- Scott M Reba
- Department of Medicine, Case Western Reserve University,
University Hospitals, Cleveland, OH, USA
| | - Qing Li
- Department of Medicine, Case Western Reserve University,
University Hospitals, Cleveland, OH, USA
| | - Sophia Onwuzulike
- Department of Medicine, Case Western Reserve University,
University Hospitals, Cleveland, OH, USA
| | - Xuedong Ding
- Department of Medicine, Case Western Reserve University,
University Hospitals, Cleveland, OH, USA
| | - Ahmad F Karim
- Department of Medicine, Case Western Reserve University,
University Hospitals, Cleveland, OH, USA
| | - Yeritza Hernandez
- Department of Medicine, Case Western Reserve University,
University Hospitals, Cleveland, OH, USA
| | - Scott A Fulton
- Department of Medicine, Case Western Reserve University,
University Hospitals, Cleveland, OH, USA
| | - Clifford V Harding
- Pathology Department, Case Western Reserve University, University
Hospitals, Cleveland, OH, USA
- Center for AIDS Research (CFAR), Case Western Reserve University,
University Hospitals, Cleveland, OH, USA
| | - Christina L Lancioni
- Department of Pediatrics, Oregon Health and Science University,
Portland, OR, USA
| | - Nancy Nagy
- Pathology Department, Case Western Reserve University, University
Hospitals, Cleveland, OH, USA
| | - Myriam E Rodriguez
- Department of Medicine, Case Western Reserve University,
University Hospitals, Cleveland, OH, USA
| | - Pamela A Wearsch
- Pathology Department, Case Western Reserve University, University
Hospitals, Cleveland, OH, USA
| | - Roxana E Rojas
- Department of Medicine, Case Western Reserve University,
University Hospitals, Cleveland, OH, USA
- Center for AIDS Research (CFAR), Case Western Reserve University,
University Hospitals, Cleveland, OH, USA
- Department of Molecular Biology and Microbiology, Case Western
Reserve University, University Hospitals, Cleveland, OH, USA
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33
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Yu M, Zhou H, Zhao J, Xiao N, Roychowdhury S, Schmitt D, Hu B, Ransohoff RM, Harding CV, Hise AG, Hazen SL, DeFranco AL, Fox PL, Morton RE, Dicorleto PE, Febbraio M, Nagy LE, Smith JD, Wang JA, Li X. MyD88-dependent interplay between myeloid and endothelial cells in the initiation and progression of obesity-associated inflammatory diseases. ACTA ACUST UNITED AC 2014; 211:887-907. [PMID: 24752299 PMCID: PMC4010914 DOI: 10.1084/jem.20131314] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
MyD88-dependent GM-CSF production by endothelial cells plays a role in the initiation of obesity-associated inflammation by promoting adipose macrophage recruitment and M1-like polarization. Low-grade systemic inflammation is often associated with metabolic syndrome, which plays a critical role in the development of the obesity-associated inflammatory diseases, including insulin resistance and atherosclerosis. Here, we investigate how Toll-like receptor–MyD88 signaling in myeloid and endothelial cells coordinately participates in the initiation and progression of high fat diet–induced systemic inflammation and metabolic inflammatory diseases. MyD88 deficiency in myeloid cells inhibits macrophage recruitment to adipose tissue and their switch to an M1-like phenotype. This is accompanied by substantially reduced diet-induced systemic inflammation, insulin resistance, and atherosclerosis. MyD88 deficiency in endothelial cells results in a moderate reduction in diet-induced adipose macrophage infiltration and M1 polarization, selective insulin sensitivity in adipose tissue, and amelioration of spontaneous atherosclerosis. Both in vivo and ex vivo studies suggest that MyD88-dependent GM-CSF production from the endothelial cells might play a critical role in the initiation of obesity-associated inflammation and development of atherosclerosis by priming the monocytes in the adipose and arterial tissues to differentiate into M1-like inflammatory macrophages. Collectively, these results implicate a critical MyD88-dependent interplay between myeloid and endothelial cells in the initiation and progression of obesity-associated inflammatory diseases.
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Affiliation(s)
- Minjia Yu
- Department of Immunology, 2 Department of Cellular and Molecular Medicine, 3 Department of Pathobiology, 4 Department of Molecular Cardiology, Cleveland Clinic, Cleveland, OH 44195
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Funderburg NT, Stubblefield Park SR, Sung HC, Hardy G, Clagett B, Ignatz-Hoover J, Harding CV, Fu P, Katz JA, Lederman MM, Levine AD. Circulating CD4(+) and CD8(+) T cells are activated in inflammatory bowel disease and are associated with plasma markers of inflammation. Immunology 2013; 140:87-97. [PMID: 23600521 DOI: 10.1111/imm.12114] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2012] [Revised: 03/19/2013] [Accepted: 04/11/2013] [Indexed: 12/13/2022] Open
Abstract
Inflammatory bowel disease (IBD) is characterized by damage to the gut mucosa and systemic inflammation. We sought to evaluate the role of chronic inflammation on circulating T-cell activation in human subjects with Crohn's disease and ulcerative colitis. We studied 54 patients with IBD and 28 healthy controls. T-cell activation and cycling were assessed in whole blood samples by flow cytometry. Levels of lipopolysaccharide (LPS) were measured in serum by Limulus amoebocyte lysate assay, and plasma levels of inflammatory markers and LPS-binding proteins were measured by ELISA. The proportions of circulating CD4(+) and CD8(+) T lymphocytes in cycle (Ki67(+) ) are increased in patients with IBD compared with these proportions in controls. CD8(+) T cells from patients with IBD are also enriched for cells that expressed CD38 and HLA-DR, and proportions of these cells are related to plasma levels of interleukin-6 and C-reactive protein in these patients. Intracellular interleukin-2 and interferon-γ levels were elevated in resting and polyclonally activated CD4(+) and CD8(+) T cells in patients with IBD when compared with levels from healthy controls. Surprisingly, we did not find increased levels of LPS in the serum of patients with IBD. We did, however, find a signature of recent microbial translocation, as levels of LPS-binding protein are increased in the plasma of patients with IBD compared with plasma levels in healthy controls; LPS-binding protein levels are also directly related to proportions of CD38 HLA-DR-expressing CD4(+) and CD8(+) T cells. Local damage to the gastrointestinal tract in IBD may result in systemic inflammation and T-cell activation.
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Affiliation(s)
- Nicholas T Funderburg
- Department of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH 44106-4952, USA
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Gabrilovich MI, Walrath J, van Lunteren J, Nethery D, Seifu M, Kern JA, Harding CV, Tuscano L, Lee H, Williams SD, Mackay W, Tomashefski JF, Silver RF. Disordered Toll-like receptor 2 responses in the pathogenesis of pulmonary sarcoidosis. Clin Exp Immunol 2013; 173:512-22. [PMID: 23668840 DOI: 10.1111/cei.12138] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2013] [Indexed: 11/28/2022] Open
Abstract
In this study, we hypothesized that the granulomatous disorder sarcoidosis is not caused by a single pathogen, but rather results from abnormal responses of Toll-like receptors (TLRs) to conserved bacterial elements. Unsorted bronchoalveolar lavage (BAL) cells from patients with suspected pulmonary sarcoidosis and healthy non-smoking control subjects were stimulated with representative ligands of TLR-2 (in both TLR-2/1 and TLR-2/6 heterodimers) and TLR-4. Responses were determined by assessing resulting production of tumour necrosis factor (TNF)-α and interleukin (IL)-6. BAL cells from patients in whom sarcoidosis was confirmed displayed increased cytokine responses to the TLR-2/1 ligand 19-kDa lipoprotein of Mycobacterium tuberculosis (LpqH) and decreased responses to the TLR-2/6 agonist fibroblast stimulating ligand-1 (FSL)-1. Subsequently, we evaluated the impact of TLR-2 gene deletion in a recently described murine model of T helper type 1 (Th1)-associated lung disease induced by heat-killed Propionibacterium acnes. As quantified by blinded scoring of lung pathology, P. acnes-induced granulomatous pulmonary inflammation was markedly attenuated in TLR-2(-/-) mice compared to wild-type C57BL/6 animals. The findings support a potential role for disordered TLR-2 responses in the pathogenesis of pulmonary sarcoidosis.
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Affiliation(s)
- M I Gabrilovich
- Division of Pulmonary, Critical Care and Sleep Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106-4941, USA
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Abstract
Exosomes are extracellular membrane vesicles whose biogenesis by exocytosis of multivesicular endosomes was discovered in 1983. Since their discovery 30 years ago, it has become clear that exosomes contribute to many aspects of physiology and disease, including intercellular communication. We discuss the initial experiments that led to the discovery of exosomes and highlight some of the exciting current directions in the field.
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Affiliation(s)
- Clifford V Harding
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, OH 44106, USA
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Hardy GAD, Sieg S, Rodriguez B, Anthony D, Asaad R, Jiang W, Mudd J, Schacker T, Funderburg NT, Pilch-Cooper HA, Debernardo R, Rabin RL, Lederman MM, Harding CV. Interferon-α is the primary plasma type-I IFN in HIV-1 infection and correlates with immune activation and disease markers. PLoS One 2013; 8:e56527. [PMID: 23437155 PMCID: PMC3577907 DOI: 10.1371/journal.pone.0056527] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 01/10/2013] [Indexed: 11/25/2022] Open
Abstract
Type-I interferon (IFN-I) has been increasingly implicated in HIV-1 pathogenesis. Various studies have shown elevated IFN-I and an IFN-I-induced gene and protein expression signature in HIV-1 infection, yet the elevated IFN-I species has not been conclusively identified, its source remains obscure and its role in driving HIV-1 pathogenesis is controversial. We assessed IFN-I species in plasma by ELISAs and bioassay, and we investigated potential sources of IFN-I in blood and lymph node tissue by qRT-PCR. Furthermore, we measured the effect of therapeutic administration of IFNα in HCV-infected subjects to model the effect of IFNα on chronic immune activation. IFN-I bioactivity was significantly increased in plasma of untreated HIV-1-infected subjects relative to uninfected subjects (p = 0.012), and IFNα was the predominant IFN-I subtype correlating with IFN-I bioactivity (r = 0.658, p<0.001). IFNα was not detectable in plasma of subjects receiving anti-retroviral therapy. Elevated expression of IFNα mRNA was limited to lymph node tissue cells, suggesting that peripheral blood leukocytes are not a major source of IFNα in untreated chronic HIV-1 infection. Plasma IFN-I levels correlated inversely with CD4 T cell count (p = 0.003) and positively with levels of plasma HIV-1 RNA and CD38 expression on CD8 T cells (p = 0.009). In hepatitis C virus-infected subjects, treatment with IFN-I and ribavirin increased expression of CD38 on CD8 T cells (p = 0.003). These studies identify IFNα derived from lymph nodes, rather than blood leukocytes, as a possible source of the IFN-I signature that contributes to immune activation in HIV-1 infection.
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Affiliation(s)
- Gareth A. D. Hardy
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Scott Sieg
- Department of Medicine, Division of Infectious Diseases, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Benigno Rodriguez
- Department of Medicine, Division of Infectious Diseases, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Donald Anthony
- Department of Medicine, Division of Infectious Diseases, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Cleveland Veterans’ Administration Medical Center, Cleveland, Ohio, United States of America
| | - Robert Asaad
- Department of Medicine, Division of Infectious Diseases, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Wei Jiang
- Department of Medicine, Division of Infectious Diseases, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Joseph Mudd
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Department of Medicine, Division of Infectious Diseases, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Timothy Schacker
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Nicholas T. Funderburg
- Department of Medicine, Division of Infectious Diseases, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Heather A. Pilch-Cooper
- Department of Medicine, Division of Infectious Diseases, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Robert Debernardo
- Department of Obstetrics & Gynecology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Ronald L. Rabin
- Laboratory of Immunobiochemistry, Center for Biologics Evaluation and Research, United States Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Michael M. Lederman
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Department of Medicine, Division of Infectious Diseases, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
| | - Clifford V. Harding
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Department of Medicine, Division of Infectious Diseases, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- Center for AIDS Research, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, United States of America
- * E-mail:
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Simmons DP, Wearsch PA, Canaday DH, Meyerson HJ, Liu YC, Wang Y, Boom WH, Harding CV. Type I IFN drives a distinctive dendritic cell maturation phenotype that allows continued class II MHC synthesis and antigen processing. J Immunol 2012; 188:3116-26. [PMID: 22371391 DOI: 10.4049/jimmunol.1101313] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Microbial molecules or cytokines can stimulate dendritic cell (DC) maturation, which involves DC migration to lymph nodes and enhanced presentation of Ag to launch T cell responses. Microbial TLR agonists are the most studied inducers of DC maturation, but type I IFN (IFN-I) also promotes DC maturation. In response to TLR stimulation, DC maturation involves a burst of Ag processing with enhanced expression of peptide-class II MHC complexes and costimulator molecules. Subsequently, class II MHC (MHC-II) synthesis and expression in intracellular vacuolar compartments is inhibited, decreasing Ag processing function. This limits presentation to a cohort of Ags kinetically associated with the maturation stimulus and excludes presentation of Ags subsequently experienced by the DC. In contrast, our studies show that IFN-I enhances DC expression of MHC-II and costimulatory molecules without a concomitant inhibition of subsequent MHC-II synthesis and Ag processing. Expression of mRNA for MHC-II and the transcription factor CIITA is inhibited in DCs treated with TLR agonists but maintained in cells treated with IFN-I. After stimulation with IFN-I, MHC-II expression is increased on the plasma membrane but is also maintained in intracellular vacuolar compartments, consistent with sustained Ag processing function. These findings suggest that IFN-I drives a distinctive DC maturation program that enhances Ag presentation to T cells without a shutdown of Ag processing, allowing continued sampling of Ags for presentation.
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Affiliation(s)
- Daimon P Simmons
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH 44106, USA
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40
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Conry SJ, Meng Q, Hardy G, Yonkers NL, Sugalski JM, Hirsch A, Davitkov P, Compan A, Falck-Ytter Y, Blanton RE, Rodriguez B, Harding CV, Anthony DD. Genetically associated CD16(+)56(-) natural killer cell interferon (IFN)-αR expression regulates signaling and is implicated in IFN-α-induced hepatitis C virus decline. J Infect Dis 2012; 205:1131-41. [PMID: 22351942 DOI: 10.1093/infdis/jis027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Natural killer (NK) cells likely contribute to outcome of acute hepatitis C virus (HCV) infection and interferon (IFN)-induced control of chronic HCV infection. We previously observed IFN-αR and NKp30 expression associated with IFN-α-dependent NK cell activity. METHODS Here, we examined CD16(+)56(-), CD16(+)56(+), and CD16(-)56(+) NK cell subset IFN-αR and NKp30 expression in relation to magnitude of HCV genotype 1 decrease during pegylated IFN-α plus ribavirin therapy. RESULTS We observed greater baseline IFN-αR and NKp30 expression on CD16(+)56(+) and CD16(-)56(+) NK subsets in HCV-infected patients than in healthy control subjects. Baseline CD16(+)56(-) NK IFN-αR expression was associated with IFN-α-induced pSTAT1, and both were associated with magnitude of HCV decrease during pegylated IFN-α plus ribavirin therapy. Baseline CD16(+)56(-) NK IFN-αR expression was associated with race and interleukin 28B genotype, negatively associated with aspartate aminotransferase-to platelet ratio index, and positively associated with increase in NKp30 expression after in vivo IFN-α exposure. Finally, in vitro IFN-α2a-activated NK cytolysis of HCV-infected target cells was in part dependent on NKp30, and CD16(+)56(-) NK cell IFN-αR expression correlated with cytolytic activity. CONCLUSIONS IFN-αR expression on CD16(+)56(-) NK cells during chronic HCV infection may in part be genetically determined, and level of expression regulates IFN-α signaling, which in turn may contribute to control of HCV infection.
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Affiliation(s)
- Sara J Conry
- Department of Medicine, Division of Infectious Diseases, University Hospital Case Medical Center, Case Western Reserve University, Cleveland, Ohio 44106, USA
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41
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Liu YC, Simmons DP, Li X, Abbott DW, Boom WH, Harding CV. TLR2 signaling depletes IRAK1 and inhibits induction of type I IFN by TLR7/9. J Immunol 2012; 188:1019-26. [PMID: 22227568 DOI: 10.4049/jimmunol.1102181] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pathogens may signal through multiple TLRs with synergistic or antagonistic effects on the induction of cytokines, including type I IFN (IFN-I). IFN-I is typically induced by TLR9, but not TLR2. Moreover, we previously reported that TLR2 signaling by Mycobacterium tuberculosis or other TLR2 agonists inhibited TLR9 induction of IFN-I and IFN-I-dependent MHC-I Ag cross processing. The current studies revealed that lipopeptide-induced TLR2 signaling inhibited induction of first-wave IFN-α and IFN-β mRNA by TLR9, whereas induction of second-wave IFN-I mRNA was not inhibited. TLR2 also inhibited induction of IFN-I by TLR7, another MyD88-dependent IFN-I-inducing receptor, but did not inhibit IFN-I induction by TLR3 or TLR4 (both Toll/IL-1R domain-containing adapter-inducing IFN-β dependent, MyD88 independent). The inhibitory effect of TLR2 was not dependent on new protein synthesis or intercellular signaling. IL-1R-associated kinase 1 (IRAK1) was depleted rapidly (within 10 min) by TLR2 agonist, but not until later (e.g., 2 h) by TLR9 agonist. Because IRAK1 is required for TLR7/9-induced IFN-I production, we propose that TLR2 signaling induces rapid depletion of IRAK1, which impairs IFN-I induction by TLR7/9. This novel mechanism, whereby TLR2 inhibits IFN-I induction by TLR7/9, may shape immune responses to microbes that express ligands for both TLR2 and TLR7/TLR9, or responses to bacteria/virus coinfection.
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Affiliation(s)
- Yi C Liu
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH 44106, USA
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42
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Mahon RN, Sande OJ, Rojas RE, Levine AD, Harding CV, Boom WH. Mycobacterium tuberculosis ManLAM inhibits T-cell-receptor signaling by interference with ZAP-70, Lck and LAT phosphorylation. Cell Immunol 2012; 275:98-105. [PMID: 22507872 PMCID: PMC3352599 DOI: 10.1016/j.cellimm.2012.02.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 02/09/2012] [Accepted: 02/10/2012] [Indexed: 11/18/2022]
Abstract
Immune evasion is required for Mycobacterium tuberculosis to survive in the face of robust CD4(+) T cell responses. We have shown previously that M. tuberculosis cell wall glycolipids, including mannose capped lipoarabinomannan (ManLAM), directly inhibit polyclonal murine CD4(+) T cell activation by blocking ZAP-70 phosphorylation. We extended these studies to antigen-specific murine CD4(+) T cells and primary human T cells and found that ManLAM inhibited them as well. Lck and LAT phosphorylation also were inhibited by ManLAM without affecting their localization to lipid rafts. Inhibition of proximal TCR signaling was temperature sensitive, suggesting that ManLAM insertion into T cell membranes was required. Thus, M. tuberculosis ManLAM inhibits antigen-specific CD4(+) T cell activation by interfering with very early events in TCR signaling through ManLAM's insertion in T cell membranes.
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Affiliation(s)
- Robert N Mahon
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, OH 44106, United States.
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43
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Li Q, Ding X, Thomas JJ, Harding CV, Pecora ND, Ziady AG, Shank S, Boom WH, Lancioni CL, Rojas RE. Rv2468c, a novel Mycobacterium tuberculosis protein that costimulates human CD4+ T cells through VLA-5. J Leukoc Biol 2011; 91:311-20. [PMID: 22158781 DOI: 10.1189/jlb.0711364] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Mtb regulates many aspects of the host immune response, including CD4+ T lymphocyte responses that are essential for protective immunity to Mtb, and Mtb effects on the immune system are paradoxical, having the capacity to inhibit (immune evasion) and to activate (adjuvant effect) immune cells. Mtb regulates CD4+ T cells indirectly (e.g., by manipulation of APC function) and directly, via integrins and TLRs expressed on T cells. We now report that previously uncharacterized Mtb protein Rv2468c/MT2543 can directly regulate human CD4+ T cell activation by delivering costimulatory signals. When combined with TCR stimulation (e.g., anti-CD3), Rv2468c functioned as a direct costimulator for CD4+ T cells, inducing IFN-γ secretion and T cell proliferation. Studies with blocking antibodies and soluble RGD motifs demonstrated that Rv2468c engaged integrin VLA-5 (α5β1) on CD4+ T cells through its FN-like RGD motif. Costimulation by Rv2468c induced phosphorylation of FAKs and Pyk2. These results reveal that by expressing molecules that mimic host protein motifs, Mtb can directly engage receptors on CD4+ T cells and regulate their function. Rv2468c-induced costimulation of CD4+ T cells could have implications for TB immune pathogenesis and Mtb adjuvant effect.
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Affiliation(s)
- Qing Li
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
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44
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Jiang W, Lederman MM, Harding CV, Sieg SF. Presentation of soluble antigens to CD8+ T cells by CpG oligodeoxynucleotide-primed human naive B cells. J Immunol 2011; 186:2080-6. [PMID: 21239717 DOI: 10.4049/jimmunol.1001869] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Naive B lymphocytes are generally thought to be poor APCs, and there is limited knowledge of their role in activation of CD8(+) T cells. In this article, we demonstrate that class I MHC Ag presentation by human naive B cells is enhanced by TLR9 agonists. Purified naive B cells were cultured with or without a TLR9 agonist (CpG oligodeoxynucleotide [ODN] 2006) for 2 d and then assessed for phenotype, endocytic activity, and their ability to induce CD8(+) T cell responses to soluble Ags. CpG ODN enhanced expression of class I MHC and the costimulatory molecule CD86 and increased endocytic activity as determined by uptake of dextran beads. Pretreatment of naive B cells with CpG ODN also enabled presentation of tetanus toxoid to CD8(+) T cells, resulting in CD8(+) T cell cytokine production and granzyme B secretion and proliferation. Likewise, CpG-activated naive B cells showed enhanced ability to cross-present CMV Ag to autologous CD8(+) T cells, resulting in proliferation of CMV-specific CD8(+) T cells. Although resting naive B cells are poor APCs, they can be activated by TLR9 agonists to serve as potent APCs for class I MHC-restricted T cell responses. This novel activity of naive B cells could be exploited for vaccine design.
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Affiliation(s)
- Wei Jiang
- Division of Infectious Diseases and HIV Medicine, Case Western Reserve University, University Hospitals/Case Medical Center, Cleveland, OH 44106, USA.
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45
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Drage MG, Tsai HC, Pecora ND, Cheng TY, Arida AR, Shukla S, Rojas RE, Seshadri C, Moody DB, Boom WH, Sacchettini JC, Harding CV. Mycobacterium tuberculosis lipoprotein LprG (Rv1411c) binds triacylated glycolipid agonists of Toll-like receptor 2. Nat Struct Mol Biol 2010; 17:1088-95. [PMID: 20694006 PMCID: PMC2933325 DOI: 10.1038/nsmb.1869] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2010] [Accepted: 06/11/2010] [Indexed: 11/09/2022]
Abstract
Knockout of lprG results in decreased virulence of Mycobacterium tuberculosis (Mtb) in mice. Mtb lipoprotein LprG has TLR2 agonist activity, thought to be dependent on its N-terminal triacylation. Surprisingly, here we find that non-acylated LprG retains TLR2 activity. Moreover, we show LprG association with triacylated glycolipid TLR2 agonists lipoarabinomannan, lipomannan and phosphatidylinositol mannosides (which share core structures). Binding of triacylated species was specific to LprG (not LprA) and increased LprG TLR2 agonist activity; conversely, association of glycolipids with LprG enhanced their recognition by TLR2. The crystal structure of LprG in complex with phosphatidylinositol mannoside revealed a hydrophobic pocket that accommodates the three alkyl chains of the ligand. In conclusion, we demonstrate a glycolipid binding function of LprG that enhances recognition of triacylated Mtb glycolipids by TLR2 and may affect glycolipid assembly or transport for bacterial cell wall biogenesis.
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Affiliation(s)
- Michael G Drage
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio, USA
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46
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Simmons DP, Canaday DH, Liu Y, Li Q, Huang A, Boom WH, Harding CV. Mycobacterium tuberculosis and TLR2 agonists inhibit induction of type I IFN and class I MHC antigen cross processing by TLR9. J Immunol 2010; 185:2405-15. [PMID: 20660347 DOI: 10.4049/jimmunol.0904005] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dendritic cells (DCs) cross process exogenous Ags and present them by class I MHC (MHC-I) molecules to CD8(+) T cells specific for Ags from viruses and bacteria such as Mycobacterium tuberculosis. Unmethylated CpG DNA signals through TLR9 to induce type I IFN (IFN-alpha/beta), which enhances MHC-I Ag cross processing, but lipoproteins that signal through TLR2 do not induce IFN-alpha/beta. In these studies we observed that M. tuberculosis, which expresses agonists of both TLR9 and TLR2, did not induce production of IFN-alpha/beta or cross processing by murine DCs. Furthermore, M. tuberculosis and TLR2 agonists inhibited induction of IFN-alpha/beta and DC cross processing by CpG DNA. Exogenous IFN-alpha/beta effectively enhanced cross processing of M. bovis bacillus Calmette-Guérin expressing OVA, bypassing the inhibition of induction of endogenous IFN-alpha/beta. In addition, inhibition of TLR9-induced cross processing of M. bovis bacillus Calmette-Guérin expressing OVA could be circumvented by pretreating cells with CpG DNA to induce IFN-alpha/beta and MHC-I cross processing before inhibitory mycobacterial TLR2 agonists were present. Inhibition of the response to one TLR by another may affect the ultimate response to pathogens like M. tuberculosis that express agonists of multiple TLRs, including TLR2 and TLR9. This mechanism may contribute to immune evasion and explain why IFN-alpha/beta provides little contribution to host immunity to M. tuberculosis. However, downregulation of certain TLR responses may benefit the host by preventing detrimental excessive inflammation that may occur in the presence of persistent infection.
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Affiliation(s)
- Daimon P Simmons
- Department of Pathology, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, OH 44106, USA
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47
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Shin DM, Yuk JM, Lee HM, Lee SH, Son JW, Harding CV, Kim JM, Modlin RL, Jo EK. Mycobacterial lipoprotein activates autophagy via TLR2/1/CD14 and a functional vitamin D receptor signalling. Cell Microbiol 2010; 12:1648-65. [PMID: 20560977 DOI: 10.1111/j.1462-5822.2010.01497.x] [Citation(s) in RCA: 194] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In human monocytes, Toll-like receptor (TLR) 2/1 activation leads to vitamin D3-dependent antimycobacterial activities, but the molecular mechanisms by which TLR2/1 stimulation induces antimicrobial activities against mycobacteria remain unclear. Here we show that TLR2/1/CD14 stimulation by mycobacterial lipoprotein LpqH can robustly activate antibacterial autophagy through vitamin D receptor signalling activation and cathelicidin induction. We found that CCAAT/enhancer-binding protein (C/EBP)-β-dependent induction of 25-hydroxycholecalciferol-1α-hydroxylase (Cyp27b1) hydroxylase was critical for LpqH-induced cathelicidin expression and autophagy. In addition, increases in intracellular calcium following AMP-activated protein kinase (AMPK) activation played a crucial role in LpqH-induced autophagy. Moreover, AMPK-dependent p38 mitogen-activated protein kinase (MAPK) activation was required for LpqH-induced Cyp27b1 expression and autophagy activation. Collectively, these data suggest that TLR2/1/CD14-Ca(2+) -AMPK-p38 MAPK pathways contribute to C/EBP-β-dependent expression of Cyp27b1 and cathelicidin, which played an essential role in LpqH-induced autophagy. Furthermore, these results establish a previously uncharacterized signalling pathway of antimycobacterial host defence through a functional link of TLR2/1/CD14-dependent sensing to the induction of autophagy.
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Affiliation(s)
- Dong-Min Shin
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon, Korea
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48
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Liu YC, Gray RC, Hardy GAD, Kuchtey J, Abbott DW, Emancipator SN, Harding CV. CpG-B oligodeoxynucleotides inhibit TLR-dependent and -independent induction of type I IFN in dendritic cells. J Immunol 2010; 184:3367-76. [PMID: 20181884 DOI: 10.4049/jimmunol.0903079] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
CpG oligodeoxynucleotides (ODNs) signal through TLR9 to induce type I IFN (IFN-alphabeta) in dendritic cells (DCs). CpG-A ODNs are more efficacious than CpG-B ODNs for induction of IFN-alphabeta. Because IFN-alphabeta may contribute to autoimmunity, it is important to identify mechanisms to inhibit induction of IFN-alphabeta. In our studies, CpG-B ODN inhibited induction of IFN-alphabeta by CpG-A ODN, whereas induction of TNF-alpha and IL-12p40 by CpG-A ODN was not affected. CpG-B inhibition of IFN-alphabeta was observed in FLT3 ligand-induced murine DCs, purified murine myeloid DCs, plasmacytoid DCs, and human PBMCs. CpG-B ODN inhibited induction of IFN-alphabeta by agonists of multiple receptors, including MyD88-dependent TLRs (CpG-A ODN signaling via TLR9, or R837 or Sendai virus signaling via TLR7) and MyD88-independent receptors (polyinosinic:polycytidylic acid signaling via TLR3 or ds break-DNA signaling via a cytosolic pathway). CpG-B ODN did not inhibit the IFN-alphabeta positive feedback loop second-wave IFN-alphabeta, because IFN-alphabeta-induced expression of IFN-alphabeta was unaffected, and CpG-B inhibition of IFN-alphabeta was manifested in IFN-alphabetaR(-/-) DCs, which lack the positive feedback mechanism. Rather, CpG-B ODN inhibited early TLR-induced first wave IFN-alpha4 and IFN-beta. Chromatin immunoprecipitation revealed that association of IFN regulatory factor 1 with the IFN-alpha4 and IFN-beta promoters was induced by CpG-A ODN but not CpG-B ODN. Moreover, CpG-A-induced association of IFN regulatory factor 1 with these promoters was inhibited by CpG-B ODN. Our studies demonstrate a novel mechanism of transcriptional regulation of first-wave IFN-alphabeta that selectively inhibits induction of IFN-alphabeta downstream of multiple receptors and may provide targets for future therapeutic inhibition of IFN-alphabeta expression in vivo.
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Affiliation(s)
- Yi C Liu
- Department of Pathology, Case Western Reserve University, University Hospitals Case Medical Center, Cleveland, OH 44106, USA
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49
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Abstract
The first issue in selecting a system for antigen-presentation experiments is to define the appropriate type of antigen-presenting cell (APC) to study. For some experiments, crude preparations such as splenocytes or peripheral blood mononuclear cells (PBMCs) may suffice to provide APC function for stimulating T cells. This unit develops approaches for preparation of more defined APC populations, including dendritic cells (DCs), macrophages, and B lymphocytes, the three types of "professional" APC. Each of these cell types exists in different stages of differentiation, maturation, and activation, or in some cases different lineages. For example, dendritic cells may be divided into subsets, including myeloid DCs (mDCs) and plasmacytoid DCs (pDCs). Each APC type has an important antigen-presentation function, although they contribute to different aspects of the immune response. Therefore, selection of an APC type for study must include consideration of the stage or aspect of immune response that is to be modeled in the experiment.
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Abstract
Antigen processing and presentation experiments can be done with a wide variety of antigen-presenting cells (APCs). Most experiments will use one of the "professional" APC types: dendritic cells (DCs), macrophages, and B lymphocytes. Other types of cells may be used for antigen presentation in some circumstances. Each type of professional APC has an important antigen-presentation function, but the different APC types contribute to different aspects of the immune response. Therefore, selection of an APC type for study must include consideration of the stage or aspect of immune response that is to be modeled in the experiment. An important technical distinction for some types of experiments is whether the APCs are adherent or nonadherent, since this dictates the procedures that must be used to wash the cells as the medium is changed.
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