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Cappelleri A, Canesi S, Bertola L, Capo V, Zecchillo A, Albano L, Villa A, Scanziani E, Recordati C. Pneumocystis murina lesions in lungs of experimentally infected Cd40l -/- mice. Vet Pathol 2024:3009858241252409. [PMID: 38757523 DOI: 10.1177/03009858241252409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
The Cd40l-/- mouse is a well-established model of X-linked hyper-immunoglobulin M (IgM) syndrome, an immunodeficiency disorder of human beings characterized by the lack of expression of the CD40 ligand (CD40L) on activated T-cells, predisposing to infections with opportunistic pathogens like Pneumocystis jirovecii. The aim of our study was to describe the pulmonary lesions in Cd40l-/- mice experimentally infected with Pneumocystis murina, in comparison with naturally infected severe combined immunodeficient (SCID) mice. Formalin-fixed paraffin-embedded lungs from 26 Cd40l-/-, 11 SCID, and 5 uninfected Cd40l-/- mice were examined by histology and immunohistochemistry for the presence of the pathogen and for leukocyte populations (CD3, CD4, CD45R/B220, CD8a, Iba-1, Ly-6G, CD206, MHC II, and NKp46/NCR1). Infection was confirmed by immunohistochemistry in 18/26 (69%) Cd40l-/- mice and in 11/11 (100%) SCID mice. Fourteen out of 26 (54%) Cd40l-/- mice had interstitial pneumonia. Twenty-three out of 26 (88%) Cd40l-/- mice had peribronchiolar/perivascular lymphoplasmacytic infiltrates, rich in B-cells and Mott cells. Acidophilic macrophage pneumonia was additionally found in 20/26 (77%) Cd40l-/- mice. Only 4/11 (36%) SCID mice had interstitial pneumonia, but no peribronchiolar/perivascular infiltrates or acidophilic macrophage pneumonia were observed in this strain. This study represents the first description of pulmonary histopathological lesions in Cd40l-/- mice infected with P. murina. We speculate that the singular characteristics of the inflammatory infiltrates observed in Cd40l-/- mice could be explained by the specific immune phenotype of the model.
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Affiliation(s)
- Andrea Cappelleri
- Department of Veterinary Medicine and Animal Sciences, University of Milan, Lodi, Italy
- Mouse and Animal Pathology Laboratory (MAPLab), UniMi Foundation, Milan, Italy
| | - Simone Canesi
- Department of Veterinary Medicine and Animal Sciences, University of Milan, Lodi, Italy
- Mouse and Animal Pathology Laboratory (MAPLab), UniMi Foundation, Milan, Italy
| | - Luca Bertola
- Department of Veterinary Medicine and Animal Sciences, University of Milan, Lodi, Italy
- Mouse and Animal Pathology Laboratory (MAPLab), UniMi Foundation, Milan, Italy
| | - Valentina Capo
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
- National Research Council, Institute of Genetic and Biomedical Research, Milan Unit, Italy
| | - Alessandra Zecchillo
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
- National Research Council, Institute of Genetic and Biomedical Research, Milan Unit, Italy
| | - Luisa Albano
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Anna Villa
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), IRCCS San Raffaele Scientific Institute, Milan, Italy
- National Research Council, Institute of Genetic and Biomedical Research, Milan Unit, Italy
| | - Eugenio Scanziani
- Department of Veterinary Medicine and Animal Sciences, University of Milan, Lodi, Italy
- Mouse and Animal Pathology Laboratory (MAPLab), UniMi Foundation, Milan, Italy
| | - Camilla Recordati
- Department of Veterinary Medicine and Animal Sciences, University of Milan, Lodi, Italy
- Mouse and Animal Pathology Laboratory (MAPLab), UniMi Foundation, Milan, Italy
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Cao Y, Chen J, Dong L. Supplementary Role of Immunological Indicators in the Diagnosis and Prognosis of Pneumocystis Pneumonia in Non-HIV Immunocompromised Patients. Infect Drug Resist 2022; 15:4675-4683. [PMID: 36034170 PMCID: PMC9406888 DOI: 10.2147/idr.s372427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/06/2022] [Indexed: 11/23/2022] Open
Abstract
Background Pneumocystis pneumonia (PCP) has a high mortality in HIV-negative immunocompromised patients. The occurrence and development of PCP are believed to be correlated with the level of lymphocytes and their subsets. The aim of this study was to determine if the levels of lymphocyte subpopulations and immunoglobulin are associated with PCP. Methods A total of 74 immunocompromised patients were enrolled in this single-center cohort study. Diagnosis of PCP was based on the relevant pulmonary symptoms and radiological imaging, and the detection of Pneumocystis jirovecii in BAL fluid or biopsy tissue by metagenomic next-generation sequencing (mNGS). All patients were divided into two groups (PCP group and non-PCP group) and the patients in PCP group were then divided into two groupsbased on the outcome of the disease during the hospitalization. Results We observed a significant lower level of IgG (p=0.000) and B lymphocyte counts (p=0.017) in the PCP group comparing to that in the non-PCP group. CD4+ T cell counts, as well as the ratio of CD4+/CD8+ T cells in circulation and BAL fluid were also lower in the PCP group comparing to those in the non-PCP group. Lactate dehydrogenase (LDH) in the PCP group was significantly higher than that in the non-PCP group (p=0.029). In the PCP group, a lower level of total lymphocytes (p=0.004), T cells (p=0.001), CD4+ cells (p=0.001), and CD8+ cells (p=0.007), as well as the proportion of lymphocytes in BAL fluid (p=0.000) were found in deceased patients comparing to those in the survived group. Conclusion Our study revealed an important role of humoral immunity in the infection of Pneumocystis jirovecii. The level of B cells and IgG could be used as a supplement to predict the occurrence of PCP. The level of CD4+ and CD8+ lymphocytes was significantly correlated with the outcome of PCP.
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Affiliation(s)
- Yaoqian Cao
- Department of Respiratory and Critical Care Medicine, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Jiayue Chen
- Department of Respiratory and Critical Care Medicine, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Lixia Dong
- Department of Respiratory and Critical Care Medicine, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
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Proteomic Profiling and Functional Analysis of B Cell-Derived Exosomes upon Pneumocystis Infection. J Immunol Res 2022; 2022:5187166. [PMID: 35465354 PMCID: PMC9023222 DOI: 10.1155/2022/5187166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/30/2022] [Indexed: 12/27/2022] Open
Abstract
Pneumocystis is a life-threatening fungal pathogen that frequently causes fatal pneumonia (PCP) in immunocompromised individuals. Recently, B cells have been reported to play a crucial role in the pathogenesis of PCP through producing antibodies and activating CD4+ T cell response. Exosomes are nanoscale small extracellular vesicles abundant with protein cargo and can mediate immune response during infectious disease. In this study, using tandem mass tag-based quantitative proteomics coupled with bioinformatic analysis, we attempted to characterize exosomes derived from B lymphocytes in response to PCP. Several proteins were verified by parallel reaction monitoring (PRM) analysis. Also, the effects of B cell exosomes on CD4+ T cell response and phagocytic function of macrophages were clarified. Briefly, 1701 proteins were identified from B cell exosomes, and the majority of them were reported in Vesiclepedia. A total of 51 differentially expressed proteins of B cell exosomes were found in response to PCP. They were mainly associated with immune response and transcription regulation. PRM analysis confirmed the significantly changed levels of histone H1.3, vimentin, and tyrosine-protein phosphatase nonreceptor type 6 (PTPN6). Moreover, a functional study revealed the proinflammatory profile of B cell exosomes on CD4+ T cell response in PCP. Taken together, our results suggest the involvement of exosomes derived from B cells in cell-to-cell communication, providing new information on the function of B cells in response to PCP.
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New Insights into Blood Circulating Lymphocytes in Human Pneumocystis Pneumonia. J Fungi (Basel) 2021; 7:jof7080652. [PMID: 34436191 PMCID: PMC8400826 DOI: 10.3390/jof7080652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/30/2021] [Accepted: 08/05/2021] [Indexed: 01/19/2023] Open
Abstract
The host lymphocyte response is decisive in Pneumocystis pneumonia (PCP) pathophysiology but little is known of the specific roles of lymphocyte subpopulations in this fungal infection. Peripheral NK, NKT, B, TCD4+ and TCD8+ subpopulations were compared by immunophenotyping between 20 patients diagnosed with PCP (PCP(+)] and 20 uninfected immunosuppressed patients (PCP(−)). Among PCP(+) subjects, the lymphocyte populations were also compared between surviving and deceased patients. Low B cell count (<40 cells/µL) was more frequent in PCP(+) than in PCP(−) patients (p = 0.03), while there was no difference for the TCD4 count. Among the PCP(+) group, the 7 deceased patients had lower Th1 (p = 0.02) and Tc1 (p = 0.03) populations, higher Th2 response (p = 0.03), higher effector TCD8 (p < 0.01), lower central memory TCD8 (p = 0.04) and reduced NK cells (p = 0.02) compared with the 13 survivors. Th1/Th2 ratio < 17, CD8 Tc1 < 44%, effector TCD8 < 25%, central memory TCD8 < 4%, NK cells < 50 cells/µL and total lymphocytes < 0.75 G/L were associated with a higher risk of mortality (p = 0.003, p = 0.007, p = 0.0007, p = 0.004, p = 0.02 and p = 0.019, respectively). The traditional analysis of TCD4 and TCD8 populations may be insufficient in the context of PCP. It could be completed by using B cells to predict the risk of PCP, and by using lymphocyte subpopulations or total lymphocyte count, which are easy to obtain in all health care facilities, to evaluate PCP prognosis.
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Charpentier E, Ménard S, Marques C, Berry A, Iriart X. Immune Response in Pneumocystis Infections According to the Host Immune System Status. J Fungi (Basel) 2021; 7:jof7080625. [PMID: 34436164 PMCID: PMC8399367 DOI: 10.3390/jof7080625] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 12/12/2022] Open
Abstract
The host immune response is critical in Pneumocystis pneumonia (PCP). Immunocompetent hosts can eliminate the fungus without symptoms, while immunodeficient hosts develop PCP with an unsuitable excessive inflammatory response leading to lung damage. From studies based on rodent models or clinical studies, this review aimed to better understand the pathophysiology of Pneumocystis infection by analysing the role of immune cells, mostly lymphocytes, according to the immune status of the infected host. Hence, this review first describes the immune physiological response in infected immunocompetent hosts that are able to eliminate the fungus. The objective of the second part is to identify the immune elements required for the control of the fungus, focusing on specific immune deficiencies. Finally, the third part concentrates on the effect of the different immune elements in immunocompromised subjects during PCP, to better understand which cells are detrimental, and which, on the contrary, are beneficial once the disease has started. This work highlights that the immune response associated with a favourable outcome of the infection may differ according to the immune status of the host. In the case of immunocompetency, a close communication between B cells and TCD4 within tertiary lymphocyte structures appears critical to activate M2 macrophages without much inflammation. Conversely, in the case of immunodeficiency, a pro-inflammatory response including Th1 CD4, cytotoxic CD8, NK cells, and IFNγ release seems beneficial for M1 macrophage activation, despite the impact of inflammation on lung tissue.
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Affiliation(s)
- Eléna Charpentier
- Department of Parasitology-Mycology, Toulouse University Hospital, 31059 Toulouse, France;
- Infinity, Inserm, CNRS, University of Toulouse III, 31024 Toulouse, France; (S.M.); (C.M.)
- Correspondence: (E.C.); (X.I.)
| | - Sandie Ménard
- Infinity, Inserm, CNRS, University of Toulouse III, 31024 Toulouse, France; (S.M.); (C.M.)
| | - Catherine Marques
- Infinity, Inserm, CNRS, University of Toulouse III, 31024 Toulouse, France; (S.M.); (C.M.)
| | - Antoine Berry
- Department of Parasitology-Mycology, Toulouse University Hospital, 31059 Toulouse, France;
- Infinity, Inserm, CNRS, University of Toulouse III, 31024 Toulouse, France; (S.M.); (C.M.)
| | - Xavier Iriart
- Department of Parasitology-Mycology, Toulouse University Hospital, 31059 Toulouse, France;
- Infinity, Inserm, CNRS, University of Toulouse III, 31024 Toulouse, France; (S.M.); (C.M.)
- Correspondence: (E.C.); (X.I.)
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Guo CJ, Atochina-Vasserman EN, Abramova E, Smith LC, Beers MF, Gow AJ. Surfactant protein-D modulation of pulmonary macrophage phenotype is controlled by S-nitrosylation. Am J Physiol Lung Cell Mol Physiol 2019; 317:L539-L549. [PMID: 31411060 DOI: 10.1152/ajplung.00506.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Surfactant protein-D (SP-D) is a regulator of pulmonary innate immunity whose oligomeric state can be altered through S-nitrosylation to regulate its signaling function in macrophages. Here, we examined how nitrosylation of SP-D alters the phenotypic response of macrophages to stimuli both in vivo and in vitro. Bronchoalveolar lavage (BAL) from C57BL6/J and SP-D-overexpressing (SP-D OE) mice was incubated with RAW264.7 cells ± LPS. LPS induces the expression of the inflammatory genes Il1b and Nos2, which is reduced 10-fold by SP-D OE-BAL. S-nitrosylation of the SP-D OE-BAL (SNO-SP-D OE-BAL) abrogated this inhibition. SNO-SP-D OE-BAL alone induced Il1b and Nos2 expression. PCR array analysis of macrophages incubated with SP-D OE-BAL (±LPS) shows increased expression of repair genes, Ccl20, Cxcl1, and Vcam1, that was accentuated by LPS. LPS increases inflammatory gene expression, Il1a, Nos2, Tnf, and Ptgs2, which was accentuated by SNO-SP-D OE-BAL but inhibited by SP-D OE-BAL. The transcription factor NF-κB was identified as a target for SNO-SP-D by IPA, which was confirmed by Trans-AM ELISA in vitro. In vivo, SP-D overexpression increases the burden of infection in a Pneumocystis model while increasing cellular recruitment. Expression of iNOS and the production of NO metabolites were significantly reduced in SP-D OE mice relative to C57BL6/J. Inflammatory gene expression was increased in infected C57BL6/J mice but decreased in SP-D OE. SP-D oligomeric structure was disrupted in C57BL6/J infected mice but unaltered within SP-D OE. Thus SP-D modulates macrophage phenotype and the balance of multimeric to trimeric SP-D is critical to this regulation.
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Affiliation(s)
- Chang-Jiang Guo
- Environmental and Occupational Health Sciences Institute, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | | | - Elena Abramova
- Environmental and Occupational Health Sciences Institute, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | - Ley Cody Smith
- Environmental and Occupational Health Sciences Institute, Rutgers, The State University of New Jersey, Piscataway, New Jersey
| | - Michael F Beers
- School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Andrew J Gow
- Environmental and Occupational Health Sciences Institute, Rutgers, The State University of New Jersey, Piscataway, New Jersey
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McDermott AJ, Klein BS. Helper T-cell responses and pulmonary fungal infections. Immunology 2018; 155:155-163. [PMID: 29781185 DOI: 10.1111/imm.12953] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/02/2018] [Accepted: 05/11/2018] [Indexed: 12/14/2022] Open
Abstract
The mucosal surface of the respiratory tract encounters microbes, such as fungal particles, with every inhaled breath. When pathogenic fungi breach the physical barrier and innate immune system within the lung to establish an infection, adaptive immunity is engaged, often in the form of helper CD4 T-cell responses. Type 1 responses, characterized by interferon-γ production from CD4 cells, promote clearance of Histoplasma capsulatum and Cryptococcus neoformans infection. Likewise, interleukin-17A (IL-17A) production from Th17 cells promotes immunity to Blastomyces dermatitidis and Coccidioides species infection by recruiting neutrophils. In contrast the development of T helper type 2 responses, characterized by IL-5 production from T cells and eosinophil influx into the lungs, drives allergic bronchopulmonary aspergillosis and poor outcomes during C. neoformans infection. Experimental vaccines against several endemic mycoses, including Histoplasma capsulatum, Coccidioides, Cryptococcus and Blastomyces dermatitidis, induce protective T-cell responses and foreshadow the development of vaccines against pulmonary fungal infections for use in humans. Additionally, recent work using antifungal T cells as immunotherapy to protect immune-compromised patients from opportunist fungal infections also shows great promise. This review covers the role of T-cell responses in driving protection and pathology in response to pulmonary fungal infections, and highlights promising therapeutic applications of antifungal T cells.
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Affiliation(s)
- Andrew J McDermott
- Departments of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Bruce S Klein
- Departments of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,Internal Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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Pulmonary Interleukin-17-Positive Lymphocytes Increase during Pneumocystis murina Infection but Are Not Required for Clearance of Pneumocystis. Infect Immun 2017; 85:IAI.00434-16. [PMID: 28438973 PMCID: PMC5478948 DOI: 10.1128/iai.00434-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 04/14/2017] [Indexed: 12/22/2022] Open
Abstract
Pneumocystis remains an important pathogen of immunosuppressed patients, causing a potentially life-threatening pneumonia. Despite its medical importance, the immune responses required to control infection, including the role of interleukin-17 (IL-17), which is important in controlling other fungal infections, have not been clearly defined. Using flow cytometry and intracellular cytokine staining after stimulation with phorbol myristate acetate and ionomycin, we examined gamma interferon (IFN-γ), IL-4, IL-5, and IL-17 production by lung lymphocytes in immunocompetent C57BL/6 mice over time following infection with Pneumocystismurina We also examined the clearance of Pneumocystis infection in IL-17A-deficient mice. The production of both IFN-γ and IL-17 by pulmonary lymphocytes increased during infection, with maximum production at approximately days 35 to 40, coinciding with peak Pneumocystis levels in the lungs, while minimal changes were seen in IL-4- and IL-5-positive cells. The proportion of cells producing IFN-γ was consistently higher than for cells producing IL-17, with peak levels of ∼25 to 30% of CD3+ T cells for the former compared to ∼15% for the latter. Both CD4+ T cells and γδ T cells produced IL-17. Administration of anti-IFN-γ antibody led to a decrease in IFN-γ-positive cells, and an increase in IL-5-positive cells, but did not impact clearance of Pneumocystis infection. Despite the increases in IL-17 production during infection, IL-17A-deficient mice cleared Pneumocystis infection with kinetics similar to C57BL/6 mice. Thus, while IL-17 production in the lungs is increased during Pneumocystis infection in immunocompetent mice, IL-17A is not required for control of Pneumocystis infection.
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Abstract
Report of the Working Group on Hygiene of the Gesellschaft für Versuchstierkunde–Society for Laboratory Animal Science (GV-SOLAS) GV-SOLAS Working Group on Hygiene: Werner Nicklas (Chairman), Felix R. Homberger, Brunhilde Illgen-Wilcke, Karin Jacobi, Volker Kraft, Ivo Kunstyr, Michael Mähler, Herbert Meyer & Gabi Pohlmeyer-Esch
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10
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Abstract
Pneumocystis carinii pneumonia (PCP) remains a serious infection in the immunocompromised host (in the absence of HIV infection) and presents significant management and diagnostic challenges to ICU physicians. Non-HIV PCP is generally abrupt in onset, and follows a fulminate course with high rates of hospitalization, ICT admission, respiratory failure, and requirement for intubation. Mortality is generally high, especially if mechanical ventilation is required. Non-invasive ventilatory support may be considered, although the rapid progression to respiratory failure often necessitates intubation at the time of presentation. Bronchoscopy is often required to establish the diagnosis, and empirical antimicrobial treatment specifically targeted to P. carinii should be initiated while awaiting confirmation. Adjunctive corticosteroids may accelerate recovery, although their use has not yet been established in non-HIV PCP. For the ICU physicians to diagnose PCP, the non-specific presentation of an acute febrile illness and respiratory distress with diffuse pulmonary infiltrates requires a high clinical index of suspician, familiarity with clinical conditions associated with increased risk for PCP, and a low threshold for bronchoscopy to establish the diagnosis.
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Affiliation(s)
- Geoffrey S. Gilmartin
- Division of Pulmonary and Critical Care, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Henry Koziel
- Division of Pulmonary and Critical Care, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA.,
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Khalife S, Chabé M, Gantois N, Audebert C, Pottier M, Hlais S, Pinçon C, Chassat T, Pierrot C, Khalife J, Aliouat-Denis CM, Aliouat EM. Relationship Between Pneumocystis carinii Burden and the Degree of Host Immunosuppression in an Airborne Transmission Experimental Model. J Eukaryot Microbiol 2015; 63:309-17. [PMID: 26509699 DOI: 10.1111/jeu.12280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 10/18/2015] [Accepted: 10/21/2015] [Indexed: 12/13/2022]
Abstract
To quantitatively assess the risk of contamination by Pneumocystis depending on the degree of immunosuppression (ID) of the exposed rat hosts, we developed an animal model, where rats went through different doses of dexamethasone. Then, natural and aerial transmission of Pneumocystis carinii occurred during cohousing of the rats undergoing gradual ID levels (receivers) with nude rats developing pneumocystosis (seeders). Following contact between receiver and seeder rats, the P. carinii burden of receiver rats was determined by toluidine blue ortho staining and by qPCR targeting the dhfr monocopy gene of this fungus. In this rat model, the level of circulating CD4(+) and CD8(+) T lymphocytes remained significantly stable and different for each dose of dexamethasone tested, thus reaching the goal of a new stable and gradual ID rat model. In addition, an inverse relationship between the P. carinii burden and the level of circulating CD4(+) or CD8(+) T lymphocytes was evidenced. This rat model may be used to study other opportunistic pathogens or even co-infections in a context of gradual ID.
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Affiliation(s)
- Sara Khalife
- Biology and Diversity of Emerging Eukaryotic Pathogens (BDPEE), Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection and Immunity of Lille, F-59000, Lille, France.,Health and Environment Microbiology Laboratory, AZM Center for Research in Biotechnology and its Application, Doctoral School of Sciences and Technology, Lebanese University, Tripoli, Lebanon
| | - Magali Chabé
- Biology and Diversity of Emerging Eukaryotic Pathogens (BDPEE), Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection and Immunity of Lille, F-59000, Lille, France.,Department of Parasitology, Faculty of Pharmacy of Lille, Univ. Lille, F-59000, Lille, France
| | - Nausicaa Gantois
- Biology and Diversity of Emerging Eukaryotic Pathogens (BDPEE), Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection and Immunity of Lille, F-59000, Lille, France
| | | | - Muriel Pottier
- Biology and Diversity of Emerging Eukaryotic Pathogens (BDPEE), Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection and Immunity of Lille, F-59000, Lille, France.,Department of Parasitology, Faculty of Pharmacy of Lille, Univ. Lille, F-59000, Lille, France
| | - Sani Hlais
- Health and Environment Microbiology Laboratory, AZM Center for Research in Biotechnology and its Application, Doctoral School of Sciences and Technology, Lebanese University, Tripoli, Lebanon
| | - Claire Pinçon
- EA2694, Department of Biostatistics, Faculty of Pharmacy of Lille, Univ. Lille, F-59000, Lille, France
| | - Thierry Chassat
- Animal Unit, Pasteur Institute of Lille, F-59000, Lille, France
| | - Christine Pierrot
- Molecular Signaling and the Control of Parasite Growth and Differentiation, Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection and Immunity of Lille, F-59000, Lille, France
| | - Jamal Khalife
- Molecular Signaling and the Control of Parasite Growth and Differentiation, Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection and Immunity of Lille, F-59000, Lille, France
| | - Cécile-Marie Aliouat-Denis
- Biology and Diversity of Emerging Eukaryotic Pathogens (BDPEE), Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection and Immunity of Lille, F-59000, Lille, France.,Department of Parasitology, Faculty of Pharmacy of Lille, Univ. Lille, F-59000, Lille, France
| | - El Moukhtar Aliouat
- Biology and Diversity of Emerging Eukaryotic Pathogens (BDPEE), Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection and Immunity of Lille, F-59000, Lille, France.,Department of Parasitology, Faculty of Pharmacy of Lille, Univ. Lille, F-59000, Lille, France.,Molecular Signaling and the Control of Parasite Growth and Differentiation, Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection and Immunity of Lille, F-59000, Lille, France
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Treatment with Interleukin-7 Restores Host Defense against Pneumocystis in CD4+ T-Lymphocyte-Depleted Mice. Infect Immun 2015; 84:108-19. [PMID: 26483405 DOI: 10.1128/iai.01189-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/10/2015] [Indexed: 12/16/2022] Open
Abstract
Pneumocystis pneumonia (PCP) is a major cause of morbidity and mortality in patients with HIV infection. CD4(+) T lymphocytes are critical for host defense against this infection, but in the absence of CD4(+) T lymphocytes, CD8(+) T lymphocytes may provide limited host defense. The cytokine interleukin-7 (IL-7) functions to enhance lymphocyte proliferation, survival, and recruitment of immune cells to sites of infection. However, there is little known about the role of IL-7 in PCP or its potential use as an immunotherapeutic agent. We hypothesized that treatment with recombinant human IL-7 (rhIL-7) would augment host defense against Pneumocystis and accelerate pathogen clearance in CD4-depleted mice. Control and CD4-depleted mice were infected with Pneumocystis, and rhIL-7 was administered via intraperitoneal injection. Our studies indicate that endogenous murine IL-7 is part of the normal host response to Pneumocystis murina and that administration of rhIL-7 markedly enhanced clearance of Pneumocystis in CD4-depleted mice. Additionally, we observed increased recruitment of CD8(+) T lymphocytes to the lungs and decreased apoptosis of pulmonary CD8(+) T lymphocytes in rhIL-7-treated animals compared to those in untreated mice. The antiapoptotic effect of rhIL-7 was associated with increased levels of Bcl-2 protein in T lymphocytes. rhIL-7 immunotherapy in CD4-depleted mice also increased the number of gamma interferon (IFN-γ)-positive CD8(+) central memory T lymphocytes in the lungs. We conclude that rhIL-7 has a potent therapeutic effect in the treatment of murine Pneumocystis pneumonia in CD4-depleted mice. This therapeutic effect is mediated through enhanced recruitment of CD8(+) T cells and decreased apoptosis of lung T lymphocytes, with a preferential action on central memory CD8(+) T lymphocytes.
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Characterization of a distinct host response profile to Pneumocystis murina asci during clearance of pneumocystis pneumonia. Infect Immun 2013; 81:984-95. [PMID: 23319554 DOI: 10.1128/iai.01181-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Pneumocystis spp. are yeast-like fungi that cause pneumocystis pneumonia (PcP) in immunocompromised individuals and exacerbate chronic lung diseases in immunocompetent individuals. The Pneumocystis life cycle includes trophic forms and asci (cyst forms). The cell walls of Pneumocystis asci contain β-1,3-D-glucan, and treatment of PcP with β-1,3-D-glucan synthase inhibitors, such as anidulafungin, results in depletion of asci, but not trophic forms. The pulmonary host response during immune reconstitution (IR)-mediated clearance of PcP in anidulafungin-treated and untreated mice was characterized to identify ascus-specific responses. During IR, similar numbers of trophic forms were present in the anidulafungin-treated and untreated mice; however, asci were only present in the untreated mice. IR resulted in a significant reduction of trophic forms from the lungs in both groups and asci in the untreated group. The presence of asci in untreated mice correlated with increased β-glucan content in the lungs. The untreated mice mounted immune responses associated with a deleterious host inflammatory response, including increased CD8(+) T cell influx and expression of macrophage inflammatory response markers. A more robust cellular response was also observed in the untreated mice, with increased numbers of macrophages and neutrophils that were associated with greater lung damage. Markers of a Th17 response were also elevated in the untreated mice. These results suggest that the host mounts unique responses to asci and trophic forms. That these 2 life cycle stages provoked distinct host response profiles has significant implications for clearance and interpretation of the host immune responses to PcP.
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Abstract
Although the incidence of Pneumocystis pneumonia (PCP) has decreased since the introduction of combination antiretroviral therapy, it remains an important cause of disease in both HIV-infected and non-HIV-infected immunosuppressed populations. The epidemiology of PCP has shifted over the course of the HIV epidemic both from changes in HIV and PCP treatment and prevention and from changes in critical care medicine. Although less common in non-HIV-infected immunosuppressed patients, PCP is now more frequently seen due to the increasing numbers of organ transplants and development of novel immunotherapies. New diagnostic and treatment modalities are under investigation. The immune response is critical in preventing this disease but also results in lung damage, and future work may offer potential areas for vaccine development or immunomodulatory therapy. Colonization with Pneumocystis is an area of increasing clinical and research interest and may be important in development of lung diseases such as chronic obstructive pulmonary disease. In this review, we discuss current clinical and research topics in the study of Pneumocystis and highlight areas for future research.
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Kasper LH, Buzoni-Gatel D. Some Opportunistic Parasitic Infections in AIDS: Candidiasis, Pneumocystosis, Cryptosporidiosis, Toxoplasmosis. ACTA ACUST UNITED AC 2011; 14:150-6. [PMID: 17040733 DOI: 10.1016/s0169-4758(97)01212-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Almost 80% of patients with AIDS die from infections other than human immunodeficiency virus (HIV). These infections usually occur late in the course of disease when CD4(+) T-cell count has fallen below 200 permm(3) cells per milliliter. Most of these infections are caused by organisms that do not normally afflict healthy individuals and are thus considered to be opportunistic. In this article, Lloyd Kasper and Dominique Buzoni-Gatel review the host-parasite interaction for four important pathogens: Candida albicans and Pneumocystis carinii (usually non-invasive pathogens), Cryptosporidium parvum (invades the cells but remains localized in the gut) and Toxoplasma gondii (penetrates through the gut to cause systemic infection). These organisms, which generally cause limited or even insignificant clinical evidence of infection in the normal host, were chosen because of their high prevalence in AIDS patients and because they exhibit different invasive abilities. The reason why individuals with AIDS are susceptible to this particular group of pathogens is uncertain.
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Affiliation(s)
- L H Kasper
- Departments of Medicine (Neurology) and Microbiology, Dartmouth Medical School, Hanover, NH 03756, USA
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Catherinot E, Lanternier F, Bougnoux ME, Lecuit M, Couderc LJ, Lortholary O. Pneumocystis jirovecii Pneumonia. Infect Dis Clin North Am 2010; 24:107-38. [PMID: 20171548 DOI: 10.1016/j.idc.2009.10.010] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Pneumocystis jirovecii has gained attention during the last decade in the context of the AIDS epidemic and the increasing use of cytotoxic and immunosuppressive therapies. This article summarizes current knowledge on biology, pathophysiology, epidemiology, diagnosis, prevention, and treatment of pulmonary P jirovecii infection, with a particular focus on the evolving pathophysiology and epidemiology. Pneumocystis pneumonia still remains a severe opportunistic infection, associated with a high mortality rate.
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Affiliation(s)
- Emilie Catherinot
- Université Paris Descartes, Service de Maladies Infectieuses et Tropicales, 149 Rue de Sèvres, Centre d'Infectiologie Necker-Pasteur, Hôpital Necker-Enfants Malades, Paris 75015, France
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Atochina-Vasserman EN, Gow AJ, Abramova H, Guo CJ, Tomer Y, Preston AM, Beck JM, Beers MF. Immune reconstitution during Pneumocystis lung infection: disruption of surfactant component expression and function by S-nitrosylation. THE JOURNAL OF IMMUNOLOGY 2009; 182:2277-87. [PMID: 19201882 DOI: 10.4049/jimmunol.0802775] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pneumocystis pneumonia (PCP), the most common opportunistic pulmonary infection associated with HIV infection, is marked by impaired gas exchange and significant hypoxemia. Immune reconstitution disease (IRD) represents a syndrome of paradoxical respiratory failure in patients with active or recently treated PCP subjected to immune reconstitution. To model IRD, C57BL/6 mice were selectively depleted of CD4(+) T cells using mAb GK1.5. Following inoculation with Pneumocystis murina cysts, infection was allowed to progress for 2 wk, GK1.5 was withdrawn, and mice were followed for another 2 or 4 wk. Flow cytometry of spleen cells demonstrated recovery of CD4(+) cells to >65% of nondepleted controls. Lung tissue and bronchoalveolar lavage fluid harvested from IRD mice were analyzed in tandem with samples from CD4-depleted mice that manifested progressive PCP for 6 wks. Despite significantly decreased pathogen burdens, IRD mice had persistent parenchymal lung inflammation, increased bronchoalveolar lavage fluid cellularity, markedly impaired surfactant biophysical function, and decreased amounts of surfactant phospholipid and surfactant protein (SP)-B. Paradoxically, IRD mice also had substantial increases in the lung collectin SP-D, including significant amounts of an S-nitrosylated form. By native PAGE, formation of S-nitrosylated SP-D in vivo resulted in disruption of SP-D multimers. Bronchoalveolar lavage fluid from IRD mice selectively enhanced macrophage chemotaxis in vitro, an effect that was blocked by ascorbate treatment. We conclude that while PCP impairs pulmonary function and produces abnormalities in surfactant components and biophysics, these responses are exacerbated by IRD. This worsening of pulmonary inflammation, in response to persistent Pneumocystis Ags, is mediated by recruitment of effector cells modulated by S-nitrosylated SP-D.
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Affiliation(s)
- Elena N Atochina-Vasserman
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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Critical roles of inflammation and apoptosis in improved survival in a model of hyperoxia-induced acute lung injury in Pneumocystis murina-infected mice. Infect Immun 2009; 77:1053-60. [PMID: 19124601 DOI: 10.1128/iai.00967-08] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pneumocystis infections increase host susceptibility to additional insults that would be tolerated in the absence of infection, such as hyperoxia. In an in vivo model using CD4-depleted mice, we previously demonstrated that Pneumocystis murina pneumonia causes significant mortality following an otherwise nonlethal hyperoxic insult. Infected mice demonstrated increased pulmonary inflammation and alveolar epithelial cell apoptosis compared to controls. To test the mechanisms underlying these observations, we examined expression of components of the Fas-Fas ligand pathway in P. murina-infected mice exposed to hyperoxia. Hyperoxia alone increased expression of Fas on the surface of type II alveolar epithelial cells; conversely, infection with P. murina led to increased lung expression of Fas ligand. We hypothesized that inhibition of inflammatory responses or direct inhibition of alveolar epithelial cell apoptosis would improve survival in P. murina-infected mice exposed to hyperoxia. Mice were depleted of CD4(+) T cells and infected with P. murina and then were exposed to >95% oxygen for 4 days, followed by return to normoxia. Experimental groups received vehicle, dexamethasone, or granulocyte-macrophage colony-stimulating factor (GM-CSF). Compared with the vehicle-treated group, treatment with dexamethasone reduced Fas ligand expression and significantly improved survival. Similarly, treatment with GM-CSF, an agent we have shown protects alveolar epithelial cells against apoptosis, decreased Fas ligand expression and also improved survival. Our results suggest that the dual stresses of P. murina infection and hyperoxia induce lung injury via activation of the Fas-Fas ligand pathway and that corticosteroids and GM-CSF reduce mortality in P. murina-infected mice exposed to hyperoxic stress by inhibition of inflammation and apoptosis.
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Christensen PJ, Preston AM, Ling T, Du M, Fields WB, Curtis JL, Beck JM. Pneumocystis murina infection and cigarette smoke exposure interact to cause increased organism burden, development of airspace enlargement, and pulmonary inflammation in mice. Infect Immun 2008; 76:3481-90. [PMID: 18490462 PMCID: PMC2493196 DOI: 10.1128/iai.00165-08] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 03/08/2008] [Accepted: 05/11/2008] [Indexed: 11/20/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is characterized by the presence of airflow obstruction and lung destruction with airspace enlargement. In addition to cigarette smoking, respiratory pathogens play a role in pathogenesis, but specific organisms are not always identified. Recent reports demonstrate associations between the detection of Pneumocystis jirovecii DNA in lung specimens or respiratory secretions and the presence of emphysema in COPD patients. Additionally, human immunodeficiency virus-infected individuals who smoke cigarettes develop early emphysema, but a role for P. jirovecii in pathogenesis remains speculative. We developed a new experimental model using immunocompetent mice to test the interaction of cigarette smoke exposure and environmentally acquired Pneumocystis murina infection in vivo. We hypothesized that cigarette smoke and P. murina would interact to cause increases in total lung capacity, airspace enlargement, and pulmonary inflammation. We found that exposure to cigarette smoke significantly increases the lung organism burden of P. murina. Pulmonary infection with P. murina, combined with cigarette smoke exposure, results in changes in pulmonary function and airspace enlargement characteristic of pulmonary emphysema. P. murina and cigarette smoke exposure interact to cause increased lung inflammatory cell accumulation. These findings establish a novel animal model system to explore the role of Pneumocystis species in the pathogenesis of COPD.
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Affiliation(s)
- Paul J Christensen
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48105, USA
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Hernandez-Novoa B, Bishop L, Logun C, Munson PJ, Elnekave E, Rangel ZG, Barb J, Danner RL, Kovacs JA. Immune responses to Pneumocystis murina are robust in healthy mice but largely absent in CD40 ligand-deficient mice. J Leukoc Biol 2008; 84:420-30. [PMID: 18467653 DOI: 10.1189/jlb.1207816] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Pneumocystis is a pathogen of immunocompromised hosts but can also infect healthy hosts, in whom infection is rapidly controlled and cleared. Microarray methods were used to examine differential gene expression in the lungs of C57BL/6 and CD40 ligand knockout (CD40L-KO) mice over time following exposure to Pneumocystis murina. Immunocompetent C57BL/6 mice, which control and clear infection efficiently, showed a robust response to infection characterized by the up-regulation of 349 primarily immune response-associated genes. Temporal changes in the expression of these genes identified an early (Week 2), primarily innate response, which waned before the infection was controlled; this was followed by primarily adaptive immune responses that peaked at Week 5, which coincided with clearance of the infection. In conjunction with the latter, there was an increased expression of B cell-associated (Ig) genes at Week 6 that persisted through 11 weeks. In contrast, CD40L-KO mice, which are highly susceptible to developing severe Pneumocystis pneumonia, showed essentially no up-regulation of immune response-associated genes at Days 35-75. Immunohistochemical staining supported these observations by demonstrating an increase in CD4+, CD68+, and CD19+ cells in C57BL/6 but not CD40L-KO mice. Thus, the healthy host demonstrates a robust, biphasic response to infection by Pneumocystis; CD40L is an essential upstream regulator of the adaptive immune responses that efficiently control infection and prevent development of progressive pneumonia.
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Affiliation(s)
- Beatriz Hernandez-Novoa
- Critical Care Medicine Department, National Institutes of Health Clinical Center, NIH, Building 10, Room 2C145, MSC 1662, Bethesda, MD 20892-1662, USA
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Vahid B, Bibbo M, Marik PE. Role of CD8 lymphocytes and neutrophilic alveolitis in Pneumocystis jiroveci pneumonia. ACTA ACUST UNITED AC 2007; 39:612-4. [PMID: 17577827 DOI: 10.1080/00365540601115946] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
We described the characteristics of bronchoalveolar inflammatory cells and their correlation with lung injury in patients with Pneumocystis jiroveci pneumonia. We reviewed all cases of patients with Pneumocystis jiroveci pneumonia in newly diagnosed HIV infected patients admitted to a large metropolitan referral hospital during June 2003 to December 2004. Nine patients (5M, 4F) with Pneumocystis jiroveci pneumonia diagnosed with bronchoscopy and cytological examination of bronchoalveolar lavage (BAL) were identified. There was a positive correlation between peripheral CD8 count and BAL neutrophilia and negative correlation with hypoxemia. Although the number patients in this case series is small, our findings suggest that CD8 cells and alveolar neutrophilic inflammation have a role in lung injury in Pneumocystis jiroveci pneumonia. These findings are consistent with data from animal studies.
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Affiliation(s)
- Bobbak Vahid
- Department of Pulmonary and Critical Care Medicine, Thomas Jefferson University, Philadelphia, USA.
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McKinley L, Logar AJ, McAllister F, Zheng M, Steele C, Kolls JK. Regulatory T cells dampen pulmonary inflammation and lung injury in an animal model of pneumocystis pneumonia. THE JOURNAL OF IMMUNOLOGY 2006; 177:6215-26. [PMID: 17056551 PMCID: PMC3912571 DOI: 10.4049/jimmunol.177.9.6215] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CD4+CD25+FoxP3+ regulatory T cells are decreased in patients infected with HIV and have been shown to be critical in mediating Ag tolerance in the lung. Because a subset of Pneumocystis-infected individuals develop substantial lung injury, which can be modeled in immune reconstituted scid mice, we used mouse models of Pneumocystis carinii to investigate the role of regulatory T cells in opportunistic infection and immune reconstitution. In this study, we show that CD4+CD25+FoxP3+ cells are part of the host response to Pneumocystis in CD4+ T cell-intact mice. Moreover, lung injury and proinflammatory Th1 and Th2 cytokine levels in the bronchoalveolar lavage fluid and lung homogenate were increased following CD4+CD25- immune reconstitution in Pneumocystis-infected SCID mice but not in CD4+CD25+ T cell-reconstituted animals. The ability of CD4+CD25+ T cells to control inflammation and injury during the course of Pneumocystis was confirmed by treatment of wild-type C57BL/6 mice with anti-CD25 mAb. These data show that CD4+CD25+ T cells control pulmonary inflammation and lung injury associated with Pneumocystis infection both in the setting of immune reconstitution as well as new acquisition of infection.
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Affiliation(s)
| | | | | | | | | | - Jay K. Kolls
- Address correspondence and reprint requests to Dr. Jay K. Kolls, Children’s Hospital of Pittsburgh, Suite 3765, 3705 Fifth Avenue, Pittsburgh, PA 15213.
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Gigliotti F, Crow EL, Bhagwat SP, Wright TW. Sensitized CD8+ T cells fail to control organism burden but accelerate the onset of lung injury during Pneumocystis carinii pneumonia. Infect Immun 2006; 74:6310-6. [PMID: 16940142 PMCID: PMC1695514 DOI: 10.1128/iai.00668-06] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
While CD8+ cells have been shown to contribute to lung injury during Pneumocystis carinii pneumonia (PCP), there are conflicting reports concerning the ability of CD8+ cells to kill P. carinii. To address these two issues, we studied the effect of the presence of CD8+ cells in two mouse models of PCP. In the reconstituted SCID mouse model, depletion of CD8+ cells in addition to CD4+ cells after reconstitution did not result in increased numbers of P. carinii cysts compared to the numbers of cysts in mice with only CD4+ cells depleted. This result was observed regardless of whether the mice were reconstituted with naïve or P. carinii-sensitized lymphocytes. In contrast, reconstitution with sensitized lymphocytes resulted in more rapid onset of lung injury that was dependent on the presence of CD8+ cells. The course of organism replication over a 6-week period was also examined in the CD4+-T-cell-depleted and CD4+- and CD8+-T-cell-depleted mouse model of PCP. Again, the organism burdens were identical at all times regardless of whether CD8+ cells were present. Thus, in the absence of CD4+ T cells, CD8+ T cells are a key contributor to the inflammatory lung injury associated with PCP. However, we were unable to demonstrate an in vivo effect of these cells on the course of P. carinii infection.
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Affiliation(s)
- Francis Gigliotti
- Department of Pediatrics, University of Rochester School of Medicine & Dentistry, 601 Elmwood Avenue, Box 690, Rochester, NY 14642, USA.
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Bhagwat SP, Gigliotti F, Xu H, Wright TW. Contribution of T cell subsets to the pathophysiology of Pneumocystis-related immunorestitution disease. Am J Physiol Lung Cell Mol Physiol 2006; 291:L1256-66. [PMID: 16891394 PMCID: PMC4161614 DOI: 10.1152/ajplung.00079.2006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Immune-mediated lung injury is an important component of Pneumocystis pneumonia (PcP)-related immunorestitution disease (IRD). However, the individual contribution of CD4(+) and CD8(+) T cells to the pathophysiology of IRD remains undetermined. Therefore, IRD was modeled in severe combined immunodeficient mice, and specific T cell depletion was used to determine how T cell subsets interact to affect the nature and severity of disease. CD4(+) cells were more abundant than CD8(+) cells during the acute stage of IRD that coincided with impaired pulmonary physiology and organism clearance. Conversely, CD8(+) cells were more abundant during the resolution phase following P. carinii clearance. Depletion of CD4(+) T cells protected mice from the acute pathophysiology of IRD. However, these mice could not clear the infection and developed severe PcP at later time points when a pathological CD8(+) T cell response was observed. In contrast, mice depleted of CD8(+) T cells efficiently cleared the infection but developed more severe disease, an increased frequency of IFN-gamma-producing CD4(+) cells, and a prolonged CD4(+) T cell response than mice with both CD4(+) and CD8(+) cells. These data suggest that CD4(+) T cells mediate the acute respiratory disease associated with IRD. In contrast, CD8(+) T cells contributed to neither lung injury nor organism clearance when CD4(+) cells were present, but instead served to modulate CD4 function. In the absence of CD4(+) cells, CD8(+) T cells produced a nonprotective, pathological immune response. These data suggest that the interplay of CD4(+) and CD8(+) T cells affects the ultimate outcome of PcP-related IRD.
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Affiliation(s)
- Samir P. Bhagwat
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642
| | - Francis Gigliotti
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue Rochester, NY 14642
| | - Haodong Xu
- Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642
| | - Terry W. Wright
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue Rochester, NY 14642
- Corresponding Author: Terry W. Wright, Ph.D., Department of Pediatrics, P.O. Box 850, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave., Rochester, NY 14642., TEL: (585) 275-4246, FAX: (585) 756-7780,
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Zhang C, Wang SH, Lasbury ME, Tschang D, Liao CP, Durant PJ, Lee CH. Toll-like receptor 2 mediates alveolar macrophage response to Pneumocystis murina. Infect Immun 2006; 74:1857-64. [PMID: 16495560 PMCID: PMC1418649 DOI: 10.1128/iai.74.3.1857-1864.2006] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The innate immune response to Pneumocystis infection is not well understood. In this study, normal C57BL/6 mouse alveolar macrophages were found to respond to Pneumocystis murina organisms through Toll-like receptor 2 (TLR2), leading to the nuclear translocation of NF-kappaB and the production of proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha) and chemokine macrophage inflammatory protein 2 (MIP-2). P. murina stimulation of normal alveolar macrophages from C57BL/6 mice resulted in increased TLR2 transcription but not increased TLR4 transcription. In gain-of-function studies with HEK293 cells expressing TLR2 or TLR4, only TLR2 was found to stimulate an NF-kappaB response to P. murina. TNF-alpha and MIP-2 production in response to P. murina by mouse alveolar macrophages was inhibited by a monoclonal antibody that specifically blocked the ligand-binding ability of TLR2. Alveolar macrophages from TLR2 knockout (TLR2-/-) mice showed little increase in TNF-alpha and MIP-2 mRNA levels upon P. murina stimulation. An in vivo study showed that TLR2-/- mice challenged with P. murina had reduced cytokine responses. These results indicate that TLR2 plays a major role in the innate immune response to P. murina.
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Affiliation(s)
- Chen Zhang
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 1120 South Drive, Fesler Hall Rm. 419, Indianapolis, IN 46202, USA
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Lasbury ME, Durant PJ, Ray CA, Tschang D, Schwendener R, Lee CH. Suppression of alveolar macrophage apoptosis prolongs survival of rats and mice with pneumocystis pneumonia. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2006; 176:6443-53. [PMID: 16709801 DOI: 10.4049/jimmunol.176.11.6443] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The number of alveolar macrophages is decreased in patients or animals with Pneumocystis pneumonia (Pcp). This loss of alveolar macrophages is in part due to apoptosis caused by Pneumocystis infection. The mechanism of apoptosis induction is unknown. Cell-free bronchoalveolar lavage fluids from Pneumocystis-infected rats or mice have the ability to induce apoptosis in normal alveolar macrophages. To characterize the mechanisms by which apoptosis proceeds in alveolar macrophages during Pcp, specific caspase inhibitors are tested for their ability to suppress the apoptosis. In vitro induction of apoptosis can be inhibited by the caspase-9 inhibitor (Z-LEHD-FMK) but not by the inhibitor to caspase-8 or -10. The caspase-9 inhibitor can also inhibit apoptosis of alveolar macrophages in vivo when it is intranasally instilled into dexamethasone-immunosuppressed, Pneumocystis-infected rats or L3T4 cell-depleted, Pneumocystis-infected mice. The number of alveolar macrophages rebounds in caspase-9 inhibitor-treated Pcp animals. Phagocytic activity of alveolar macrophages in treated animals is also recovered, and organism burden in these animals is reduced. Administration of caspase-9 inhibitor also clears the exudate that normally fills the alveoli during Pcp and decreases lung inflammation. Furthermore, caspase-9-treated Pcp animals survive for the entire 70-day period of the study, whereas nontreated Pcp animals die 40-60 days after initiation of infection. Depletion of recovered alveolar macrophages by intranasal administration of clodronate-containing liposomes in caspase-9 inhibitor-treated animals abrogates the effects of the inhibitor. Together, these results indicate that immunomodulation of the host response may be an alternative to current treatments for Pcp.
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Affiliation(s)
- Mark E Lasbury
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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Linke M, Ashbaugh A, Demland J, Koch J, Tanaka R, Walzer P. Resolution of Pneumocystis murina infection following withdrawal of corticosteroid induced immunosuppression. Microb Pathog 2006; 40:15-22. [PMID: 16321497 DOI: 10.1016/j.micpath.2005.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Revised: 10/09/2005] [Accepted: 10/09/2005] [Indexed: 11/24/2022]
Abstract
The host response during resolution of Pneumocystis murina infection following withdrawal of Dexamethasone (Dex) induced immunosuppression was analyzed. Mice were inoculated with P. murina and treated with Dex for 4 weeks. Treatment was stopped and mice were sacrificed at d1, d7, and d14. Control mice were treated in the same manner, but were inoculated with nonviable P. murina. P. murina was actively cleared from the lungs following withdrawal of Dex treatment. No P. murina was detected in control mice. Significantly more neutrophils, lymphocytes, macrophages, and eosinophils were recovered from the lungs of mice that had been infected with P. murina than from control mice at d7, but only neutrophils remained significantly elevated at d14. Significantly more CD4+ and CD8+ T cells were purified from the lungs of mice that had been infected with P. murina mice at d7 and d14. Cytokine levels were measured in lung lavage fluid by ELISA. TNF-alpha, IFN-gamma, IL-1, and IL-6 levels were higher in mice that had been inoculated with P. murina at all three time points. TNF-alpha and IL-1 levels did not change significantly following withdrawal of Dex treatment. Low levels of IL 6 were detected at d1, but increased significantly by d7 and d14. IFN-gamma levels peaked at d14. Chemokine message levels were measured in lung tissue by ribonuclease protection assay. MIP-1beta and IP-10 message increased between d1 and d7 and then decreased by d14. RANTES message levels increased from d1 to d7 and remained elevated at d14. Withdrawal of Dex induced immunosuppression from P. murina infected mice resulted in activation of many arms of the host response that lead to resolution of the infection.
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Affiliation(s)
- Michael Linke
- Department of Veterans Affairs Medical Center, Research Service, Cincinnati, OH 45220, USA.
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30
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Rose CM, Kimzey SL, Green JM. The host response of CD28-deficient mice to Pneumocystis infection. Microb Pathog 2006; 40:23-8. [PMID: 16324820 DOI: 10.1016/j.micpath.2005.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2005] [Revised: 10/06/2005] [Accepted: 10/06/2005] [Indexed: 11/28/2022]
Abstract
Pneumocystis infection leads to a life threatening pneumonia in susceptible individuals. While depletion or dysfunction of CD4+T cells is a key determinant of susceptibility to Pneumocystis, the host response that leads to resolution of infection or lung injury is less well understood. We had previously shown that mice deficient in the T cell costimulatory molecule CD28 are susceptible to infection with Pneumocystis. A detailed analysis revealed that they clear Pneumocystis with delayed kinetics. This is associated with an influx of naïve CD8+ T cells. Depletion of CD8+ T cells did not alter organism burden, suggesting these cells are not responsible for clearance. Analysis of the cytokine milieu demonstrated a consistent increase in mRNA for IL-10 and IFN-gamma in the CD28-deficient mice. These data suggest that CD28 function in important in the efficiency of the host response to Pneumocystis pneumonia.
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Affiliation(s)
- Christine M Rose
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St Louis, MO 63110, USA
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31
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McAllister F, Steele C, Zheng M, Shellito JE, Kolls JK. In vitro effector activity of Pneumocystis murina-specific T-cytotoxic-1 CD8+ T cells: role of granulocyte-macrophage colony-stimulating factor. Infect Immun 2005; 73:7450-7. [PMID: 16239546 PMCID: PMC1273863 DOI: 10.1128/iai.73.11.7450-7457.2005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus (HIV)-related opportunistic infections continue to occur in patients who are newly diagnosed with HIV infection, those in the early course of highly active antiretroviral therapy or nonadherent to HIV care, and other immunosuppressed individuals. One of the most common opportunistic infections in these patients is Pneumocystis pneumonia. CD8+ T cells are recruited to the lung after P. carinii infection and have been associated with both lung injury and host defense. This variability may be due to subpopulations of CD8+ T cells recruited to the lung. We have previously shown using adoptive transfer studies that in vivo-generated T-cytotoxic-1 (Tc1) CD8+ T cells, defined by the secretion of gamma interferon (IFN-gamma), have effector activity against Pneumocystis spp. in vitro as well as in vivo. To better understand the mechanisms of these effects, we generated, expanded, and tested Tc1 and Tc2 CD8+ T cells specific for P. murina ex vivo. Tc1-polarized CD8+ T cells secreted higher levels of IFN-gamma and granulocyte-macrophage colony-stimulating factor (GM-CSF) and lower levels of interleukin-4 (IL-4), IL-5, IL-10, and IL-13 than Tc2 CD8+ T cells when stimulated with P. murina antigen. Moreover, Tc1 CD8+ T cells demonstrated enhanced effector activity in a macrophage-mediated killing assay which was independent of cell contact. The augmentation in macrophage-mediated P. murina killing was significantly abrogated when GM-CSF was neutralized in the Tc1 CD8+ T cells. These data support the possibility that antigen-specific GM-CSF secretion is critical for effector activity of P. murina-specific Tc1 CD8+ T cells in vitro.
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MESH Headings
- Animals
- Cell Polarity
- Cells, Cultured
- Culture Media, Conditioned/pharmacology
- Dose-Response Relationship, Drug
- Granulocyte-Macrophage Colony-Stimulating Factor/pharmacology
- Granulocyte-Macrophage Colony-Stimulating Factor/physiology
- Interferon-gamma/metabolism
- Macrophages, Alveolar/drug effects
- Macrophages, Alveolar/immunology
- Macrophages, Peritoneal/drug effects
- Macrophages, Peritoneal/immunology
- Male
- Mice
- Mice, Inbred BALB C
- Pneumocystis/immunology
- Spleen/cytology
- T-Lymphocytes, Cytotoxic/drug effects
- T-Lymphocytes, Cytotoxic/immunology
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Affiliation(s)
- Florencia McAllister
- Children's Hospital of Pittsburgh, Department of Pediatrics, Suite 3765, 3705 Fifth Ave., Pittsburgh, PA 15213, USA
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32
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Lindell DM, Moore TA, McDonald RA, Toews GB, Huffnagle GB. Generation of antifungal effector CD8+ T cells in the absence of CD4+ T cells during Cryptococcus neoformans infection. THE JOURNAL OF IMMUNOLOGY 2005; 174:7920-8. [PMID: 15944298 DOI: 10.4049/jimmunol.174.12.7920] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Immunity to the opportunistic fungus Cryptococcus neoformans is dependent on cell-mediated immunity. Individuals with defects in cellular immunity, CD4(+) T cells in particular, are susceptible to infection with this pathogen. In host defense against a number of pathogens, CD8(+) T cell responses are dependent upon CD4(+) T cell help. The goal of these studies was to determine whether CD4(+) T cells are required for the generation of antifungal CD8(+) T cell effectors during pulmonary C. neoformans infection. Using a murine intratracheal infection model, our results demonstrated that CD4(+) T cells were not required for the expansion and trafficking of CD8(+) T cells to the site of infection. CD4(+) T cells were also not required for the generation of IFN-gamma-producing CD8(+) T cell effectors in the lungs. In CD4(-) mice, depletion of CD8(+) T cells resulted in increased intracellular infection of pulmonary macrophages by C. neoformans, increasing the pulmonary burden of the infection. Neutralization of IFN-gamma in CD4(-)CD8(+) mice similarly increased macrophage infection by C. neoformans, thereby blocking the protection provided by CD8(+) T cells. Altogether, these data support the hypothesis that effector CD8(+) T cell function is independent of CD4(+) T cells and that IFN-gamma production from CD8(+) T cells plays a role in controlling C. neoformans by limiting survival of C. neoformans within macrophages.
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Affiliation(s)
- Dennis M Lindell
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
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33
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Meissner NN, Swain S, Tighe M, Harmsen A, Harmsen A. Role of type I IFNs in pulmonary complications of Pneumocystis murina infection. THE JOURNAL OF IMMUNOLOGY 2005; 174:5462-71. [PMID: 15843544 DOI: 10.4049/jimmunol.174.9.5462] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Despite the advent of highly active antiretroviral therapy, pulmonary complications in AIDS are a common clinical problem. Pneumocystis jiroveci infection causes a life-threatening pneumonia, especially in individuals with CD4 T cell deficiencies as occurs in AIDS. Although Pneumocystis sp. is an extracellular fungal pathogen, CD8 T cells are the predominant lymphocyte recruited to the lung in CD4-deficient humans and mice during Pneumocystis pneumonia, and we have found that these CD8 T cells are responsible for subsequent lung damage in CD4 T cell-depleted mice. Comparing CD4 T cell-depleted IFN-alpha receptor knockout (KO) mice to wild-type mice, we found that this CD8 T cell recruitment and lung damage is type I IFN (IFN-alphabeta) dependent. However, in both CD4 competent, wild-type and IFN-alpha receptor (IFNAR) KO mice, Pneumocystis infection leads to an eosinophilic granulocyte influx with bronchial epithelial changes as seen in asthma. This response is delayed in IFNAR KO mice, as is pathogen clearance. Although the inflammation is transient in wild-type animals and resolves upon Pneumocystis clearance, it is more severe and persists through day 35 postinfection in IFNAR KO mice, leading to fibrosis. In addition, IFNAR KO, but not wild-type, mice mount a Pneumocystis-specific IgE response, an indicator of allergic sensitization. Thus, in the absence of IFNAR signaling and CD4 T cells, Pneumocystis-mediated lung damage does not occur, whereas in CD4-competent animals, the absence of IFNAR signaling results in an exacerbated Th2 response, asthma-like symptoms, and fibrosis. Therefore, both CD4 T cell- and type I IFN-mediated mechanisms can determine pulmonary complications from Pneumocystis infection.
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MESH Headings
- Allergens/immunology
- Animals
- Antigens, Fungal/immunology
- CD4-Positive T-Lymphocytes/cytology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/pathology
- Immunoglobulin E/biosynthesis
- Interferon-alpha/metabolism
- Interferon-alpha/physiology
- Interferon-beta/physiology
- Lung/immunology
- Lung/microbiology
- Lung/pathology
- Lymphocyte Depletion
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, SCID
- Pneumocystis/immunology
- Pneumonia, Pneumocystis/genetics
- Pneumonia, Pneumocystis/immunology
- Pneumonia, Pneumocystis/pathology
- Pulmonary Eosinophilia/immunology
- Pulmonary Eosinophilia/microbiology
- Pulmonary Eosinophilia/pathology
- Receptor, Interferon alpha-beta
- Receptors, Interferon/deficiency
- Receptors, Interferon/genetics
- Receptors, Interferon/physiology
- Signal Transduction/genetics
- Signal Transduction/immunology
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Affiliation(s)
- Nicole N Meissner
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, MT 59717, USA.
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Swain SD, Wright TW, Degel PM, Gigliotti F, Harmsen AG. Neither neutrophils nor reactive oxygen species contribute to tissue damage during Pneumocystis pneumonia in mice. Infect Immun 2004; 72:5722-32. [PMID: 15385471 PMCID: PMC517543 DOI: 10.1128/iai.72.10.5722-5732.2004] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neutrophils are implicated in the damage of lung tissue in many disease states, including infectious diseases and environmental insults. These effects may be due to oxidative or nonoxidative functions of the neutrophil or both. We examined the role of neutrophils in pulmonary damage during infection with the opportunistic fungal pathogen Pneumocystis sp. in four mouse models of neutrophil dysfunction. These were (i) a knockout of the gp91(phox) component of NADPH oxidase, in which reactive oxygen species (ROS) production is greatly reduced; (ii) a double knockout of gp91(phox) and inducible nitric oxide synthase, in which ROS and nitric oxide production is greatly decreased; (iii) a knockout of the chemokine receptor CXCR2, in which accumulation of intra-alveolar neutrophils is severely diminished; and (iv) antibody depletion of circulating neutrophils in wild-type mice with the monoclonal antibody RB6. Surprisingly, in each case, indicators of pulmonary damage (respiratory rates, arterial oxygen partial pressures, and intra-alveolar albumin concentrations) were the same in knockout mice and comparable wild-type mice. Therefore, whereas neutrophils are a valid correlative marker of lung damage during Pneumocystis infection, neither neutrophils nor ROS appear to be the causative agent of tissue damage. We also show that there is no difference in Pneumocystis burdens between wild-type and knockout mice, which supports the idea that neutrophils do not have a major role in the clearance of this organism.
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Affiliation(s)
- Steve D Swain
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana 59717, USA.
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35
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Atochina EN, Beck JM, Preston AM, Haczku A, Tomer Y, Scanlon ST, Fusaro T, Casey J, Hawgood S, Gow AJ, Beers MF. Enhanced lung injury and delayed clearance of Pneumocystis carinii in surfactant protein A-deficient mice: attenuation of cytokine responses and reactive oxygen-nitrogen species. Infect Immun 2004; 72:6002-11. [PMID: 15385504 PMCID: PMC517574 DOI: 10.1128/iai.72.10.6002-6011.2004] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Surfactant protein A (SP-A), a member of the collectin family, selectively binds to Pneumocystis carinii and mediates interactions between pathogen and host alveolar macrophages in vitro. To test the hypothesis that mice lacking SP-A have delayed clearance of Pneumocystis organisms and enhanced lung injury, wild-type C57BL/6 (WT) and SP-A-deficient mice (SP-A(-/-)) with or without selective CD4(+)-T-cell depletion were intratracheally inoculated with Pneumocystis organisms. Four weeks later, CD4-depleted SP-A-deficient mice had developed a more severe Pneumocystis infection than CD4-depleted WT (P. carinii pneumonia [PCP] scores of 3 versus 2, respectively). Whereas all non-CD4-depleted WT mice were free of PCP, intact SP-A(-/-) mice also had evidence of increased organism burden. Pneumocystis infection in SP-A-deficient mice was associated histologically with enhanced peribronchial and/or perivascular cellularity (score of 4 versus 2, SP-A(-/-) versus C57BL/6 mice, respectively) and a corresponding increase in bronchoalveolar lavage (BAL) cell counts. Increases in SP-D content, gamma interferon, interleukin-4, interleukin-5, and tumor necrosis factor alpha in BAL fluid occurred but were attenuated in PCP-infected SP-A(-/-) mice compared to WT mice. There were increases in total BAL NO levels in both infected groups, but nitrite levels were higher in SP-A(-/-) mice, indicating a reduction in production of higher oxides of nitrogen that was also reflected in lower levels of 3-nitrotyrosine staining in the SP-A(-/-) group. We conclude that despite increases in inflammatory cells, SP-A-deficient mice infected with P. carinii exhibit an enhanced susceptibility to the organism and attenuated production of proinflammatory cytokines and reactive oxygen-nitrogen species. These data support the concept that SP-A is a local effector molecule in the lung host defense against P. carinii in vivo.
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Affiliation(s)
- Elena N. Atochina
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, Division of Neonatology, University of California at San Francisco, San Francisco, California
| | - James M. Beck
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, Division of Neonatology, University of California at San Francisco, San Francisco, California
| | - Angela M. Preston
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, Division of Neonatology, University of California at San Francisco, San Francisco, California
| | - Angela Haczku
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, Division of Neonatology, University of California at San Francisco, San Francisco, California
| | - Yaniv Tomer
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, Division of Neonatology, University of California at San Francisco, San Francisco, California
| | - Seth T. Scanlon
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, Division of Neonatology, University of California at San Francisco, San Francisco, California
| | - Trevor Fusaro
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, Division of Neonatology, University of California at San Francisco, San Francisco, California
| | - John Casey
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, Division of Neonatology, University of California at San Francisco, San Francisco, California
| | - Samuel Hawgood
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, Division of Neonatology, University of California at San Francisco, San Francisco, California
| | - Andrew J. Gow
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, Division of Neonatology, University of California at San Francisco, San Francisco, California
| | - Michael F. Beers
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pennsylvania School of Medicine, Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School and Veterans Affairs Medical Center, Ann Arbor, Michigan, Division of Neonatology, University of California at San Francisco, San Francisco, California
- Corresponding author. Mailing address: Pulmonary and Critical Care Division, University of Pennsylvania School of Medicine, 807 BRB II/III Bldg., 421 Curie Blvd., Philadelphia, PA 19104. Phone: (215) 898-9106. Fax: (215) 573-4469. E-mail:
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36
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McAllister F, Mc Allister F, Steele C, Zheng M, Young E, Shellito JE, Marrero L, Kolls JK. T cytotoxic-1 CD8+ T cells are effector cells against pneumocystis in mice. THE JOURNAL OF IMMUNOLOGY 2004; 172:1132-8. [PMID: 14707088 DOI: 10.4049/jimmunol.172.2.1132] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Host defenses are profoundly compromised in HIV-infected hosts due to progressive depletion of CD4+ T lymphocytes. A hallmark of HIV infection is Pneumocystis carinii (PC) pneumonia. Recently, CD8+ T cells, which are recruited to the lung in large numbers in response to PC infection, have been associated with some level of host defense as well as contributing to lung injury in BALB/c mice. In this study, we show that CD8+ T cells that have a T cytotoxic-1 response to PC in BALB/c mice, as determined by secretion of IFN-gamma, have in vitro killing activity against PC and effect clearance of the organism in adoptive transfer studies. Moreover, non-T cytotoxic-1 CD8+ T cells lacked in vitro effector activity and contributed to lung injury upon adoptive transfer. This dichotomous response in CD8+ T cell response may in part explain the clinical heterogeneity in the severity of PC pneumonia.
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MESH Headings
- Adenoviridae/genetics
- Animals
- CD4-Positive T-Lymphocytes/cytology
- Chemokine CXCL10
- Chemokine CXCL9
- Chemokines, CXC/biosynthesis
- Cytotoxicity Tests, Immunologic
- Cytotoxicity, Immunologic
- Genetic Vectors
- Intercellular Signaling Peptides and Proteins/biosynthesis
- Interferon-gamma/administration & dosage
- Interferon-gamma/genetics
- Interferon-gamma/pharmacokinetics
- Lung/cytology
- Lung/immunology
- Lung/microbiology
- Lymphocyte Depletion
- Male
- Mice
- Mice, Inbred BALB C
- Mice, SCID
- Neutrophil Infiltration/genetics
- Neutrophil Infiltration/immunology
- Pneumocystis carinii/growth & development
- Pneumocystis carinii/immunology
- Pneumonia, Pneumocystis/immunology
- Pneumonia, Pneumocystis/microbiology
- Pneumonia, Pneumocystis/pathology
- Pneumonia, Pneumocystis/virology
- Receptors, CXCR3
- Receptors, Chemokine/biosynthesis
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/microbiology
- T-Lymphocyte Subsets/virology
- T-Lymphocytes, Regulatory/cytology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/microbiology
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Affiliation(s)
- Florencia McAllister
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh, 3705 Fifth Avenue, Pittsburgh, PA 15213, USA
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37
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Kolls JK. HIV immunology and new therapies. Pediatr Pulmonol Suppl 2004; 26:59-61. [PMID: 15029598 DOI: 10.1002/ppul.70052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Jay K Kolls
- Department of Pediatrics, Division of Pediatric Pulmonology, Children's Hospital of Pittsburgh, Suite 3765, 3705 Fifth Ave, Pittsburgh, PA 15143, USA.
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38
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Thullen TD, Ashbaugh AD, Daly KR, Linke MJ, Steele PE, Walzer PD. Sensitized splenocytes result in deleterious cytokine cascade and hyperinflammatory response in rats with Pneumocystis pneumonia despite the presence of corticosteroids. Infect Immun 2004; 72:757-65. [PMID: 14742518 PMCID: PMC321630 DOI: 10.1128/iai.72.2.757-765.2004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The immune response to the opportunistic pulmonary pathogen Pneumocystis can have beneficial and harmful effects on the host despite the presence of corticosteroids. We hypothesized that this deleterious hyperinflammatory response is associated with exaggerated cytokine production. The adoptive transfer of at least 10(7) immune splenocytes reduced the cyst count in rats with corticosteroid-induced pneumocystosis. About 18% of these rats developed clinical illness, an increased lung weight/body weight (LW/BW) ratio, and elevated levels of interleukin 1alpha (IL-1alpha), IL-1beta, IL-6, tumor necrosis factor alpha, IL-5, IL-10, and gamma interferon in the lungs. This hyperinflammatory reaction was not observed in rats that remained clinically well or in control rats. Thus, in this model, corticosteroids have little effect on the cytokine cascade or other adverse effects of the host immune response to Pneumocystis.
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39
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Wright TW, Pryhuber GS, Chess PR, Wang Z, Notter RH, Gigliotti F. TNF Receptor Signaling Contributes to Chemokine Secretion, Inflammation, and Respiratory Deficits duringPneumocystisPneumonia. THE JOURNAL OF IMMUNOLOGY 2004; 172:2511-21. [PMID: 14764724 DOI: 10.4049/jimmunol.172.4.2511] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD8(+) T cells contribute to the pathophysiology of Pneumocystis pneumonia (PcP) in a murine model of AIDS-related disease. The present studies were undertaken to more precisely define the mechanisms by which these immune cells mediate the inflammatory response that leads to lung injury. Experimental mice were depleted of either CD4(+) T cells or both CD4(+) and CD8(+) T cells and then infected with Pneumocystis: The CD4(+)-depleted mice had significantly greater pulmonary TNF-alpha levels than mice depleted of both CD4(+) and CD8(+) T cells. Elevated TNF-alpha levels were associated with increased lung concentrations of the chemokines RANTES, monocyte chemoattractant protein 1, macrophage-inflammatory protein 2, and cytokine-induced neutrophil chemoattractant. To determine whether TNFR signaling was involved in the CD8(+) T cell-dependent chemokine response, TNFRI- and II-deficient mice were CD4(+) depleted and infected with Pneumocystis: TNFR-deficient mice had significantly reduced pulmonary RANTES, monocyte chemoattractant protein 1, macrophage-inflammatory protein 2, and cytokine-induced neutrophil chemoattractant responses, reduced inflammatory cell recruitment to the alveoli, and reduced histological evidence of PcP-related alveolitis as compared with infected wild-type mice. Diminished pulmonary inflammation correlated with improved surfactant activity and improved pulmonary function in the TNFR-deficient mice. These data indicate that TNFR signaling is required for maximal CD8(+) T cell-dependent pulmonary inflammation and lung injury during PcP and also demonstrate that CD8(+) T cells can use TNFR signaling pathways to respond to an extracellular fungal pathogen.
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MESH Headings
- Animals
- Bronchoalveolar Lavage Fluid/chemistry
- Bronchoalveolar Lavage Fluid/cytology
- Bronchoalveolar Lavage Fluid/immunology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/pathology
- Cell Movement/immunology
- Chemokines/biosynthesis
- Chemokines/metabolism
- Dose-Response Relationship, Immunologic
- Female
- Inflammation Mediators/physiology
- Lung/blood supply
- Lung/immunology
- Lung/pathology
- Lung/physiopathology
- Lung Compliance
- Mice
- Mice, SCID
- Mice, Transgenic
- Pneumonia, Pneumocystis/genetics
- Pneumonia, Pneumocystis/immunology
- Pneumonia, Pneumocystis/pathology
- Pneumonia, Pneumocystis/physiopathology
- Pulmonary Surfactants/metabolism
- Receptors, Tumor Necrosis Factor/deficiency
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/physiology
- Respiratory Function Tests
- Signal Transduction/genetics
- Signal Transduction/immunology
- Tumor Necrosis Factor-alpha/biosynthesis
- Tumor Necrosis Factor-alpha/physiology
- Up-Regulation/genetics
- Up-Regulation/immunology
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Affiliation(s)
- Terry W Wright
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
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40
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Abstract
Pneumocystis jiroveci (P. carinii) is an opportunistic pathogen that has gained particular prominence since the onset of the AIDS epidemic. Among several important advances in diagnosis and management, appropriately targeting chemoprophylaxis to HIV-infected patients at high clinical risk for P. jiroveci pneumonia and the introduction of effective combination anti-retroviral therapy (including highly active antiretroviral therapy [HAART]) have contributed to the reduced incidence of P. jiroveci pneumonia. Despite the success of these clinical interventions, P. jiroveci pneumonia remains the most common opportunistic pneumonia and the most common life-threatening infectious complication in HIV-infected patients. Trimethoprim/sulfamethoxazole (cotrimoxazole) remains the first-line agent for effective therapy and chemoprophylaxis, and corticosteroids represent an important adjunctive agent in the treatment of moderate-to-severe P. jiroveci pneumonia. However, problems of chemoprophylaxis and treatment failures, high rates of adverse drug reactions and drug intolerance to first-line antimicrobials, high rates of relapse or recurrence with second-line agents, and newer concerns about the development of P. jiroveci drug resistance represent formidable challenges to the management and treatment of AIDS-related P. jiroveci pneumonia. With the expanding global problem of HIV infection, the intolerance or unavailability of HAART to many individuals and limited access to healthcare for HIV-infected patients, P. jiroveci pneumonia will remain a major worldwide problem in the HIV-infected population. New drugs under development as anti-Pneumocystis agents such as echinocandins and pneumocandins, which inhibit beta-glucan synthesis, or sordarins, which inhibit fungal protein synthesis, show promise as effective agents. Continued basic research into the biology and genetics of P. jiroveci and host defense response to P. jiroveci will allow the development of newer antimicrobials and immunomodulatory therapeutic agents to more effectively treat life-threatening pneumonia caused by this organism.
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Affiliation(s)
- Naimish Patel
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, 330 Brookline Avenue, Boston, MA 02115, USA
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41
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Thullen TD, Ashbaugh AD, Daly KR, Linke MJ, Steele PE, Walzer PD. New rat model of Pneumocystis pneumonia induced by anti-CD4(+) T-lymphocyte antibodies. Infect Immun 2003; 71:6292-7. [PMID: 14573648 PMCID: PMC219604 DOI: 10.1128/iai.71.11.6292-6297.2003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The CD4(+) T lymphocyte plays a central role in host defense against Pneumocystis pneumonia but has received only limited attention in rats. CD4(+) T-cell-depleting (OX-38) and nondepleting (W3/25) monoclonal antibodies, which recognize an identical or adjacent epitope, were administered for up to 14 weeks to Lewis rats that had been exposed to PNEUMOCYSTIS: While OX-38 produced a greater decrease in circulating CD4(+) cells than W3/25, both antibody treatments resulted in similar effects on the health of the rats and the levels of Pneumocystis pneumonia, which were milder than those found with corticosteroids. W3/25 also did not enhance the severity of Pneumocystis pneumonia achieved with corticosteroids alone. We conclude that CD4(+) cell function is more important than CD4(+) cell number in host defense against Pneumocystis in the rat and that this new model permits study of opportunistic infections in the rat without the confounding effects of corticosteroids.
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Affiliation(s)
- Timothy D Thullen
- Veterans Affairs Medical Center, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45220, USA
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42
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Swain SD, Lee SJ, Nussenzweig MC, Harmsen AG. Absence of the macrophage mannose receptor in mice does not increase susceptibility to Pneumocystis carinii infection in vivo. Infect Immun 2003; 71:6213-21. [PMID: 14573639 PMCID: PMC219593 DOI: 10.1128/iai.71.11.6213-6221.2003] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Host defense against the opportunistic pathogen Pneumocystis carinii requires functional interactions of many cell types. Alveolar macrophages are presumed to be a vital host cell in the clearance of P. carinii, and the mechanisms of this interaction have come under scrutiny. The macrophage mannose receptor is believed to play an important role as a receptor involved in the binding and phagocytosis of P. carinii. Although there is in vitro evidence for this interaction, the in vivo role of this receptor in P. carinii clearance in unclear. Using a mouse model in which the mannose receptor has been deleted, we found that the absence of this receptor is not sufficient to allow infection by P. carinii in otherwise immunocompetent mice. Furthermore, when mice were rendered susceptible to P. carinii by CD4(+) depletion, mannose receptor knockout mice (MR-KO) had pathogen loads equal to those of wild-type mice. However, the MR-KO mice exhibited a greater influx of phagocytes into the alveoli during infection. This was accompanied by increased pulmonary pathology in the MR-KO mice, as well as greater accumulation of glycoproteins in the alveoli (glycoproteins, including harmful hydrolytic enzymes, are normally cleared by the mannose receptor). We also found that the surface expression of the mannose receptor is not downregulated during P. carinii infection in wild-type mice. Our findings suggest that while the macrophage mannose receptor may be important in the recognition of P. carinii, in vivo, this mechanism may be redundant, and the absence of this receptor may be compensated for.
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Affiliation(s)
- Steve D Swain
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana 59717, USA.
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43
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Beck JM, Preston AM, Wilcoxen SE, Morris SB, White ES, Paine R. Pneumocystis pneumonia increases the susceptibility of mice to sublethal hyperoxia. Infect Immun 2003; 71:5970-8. [PMID: 14500517 PMCID: PMC201097 DOI: 10.1128/iai.71.10.5970-5978.2003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Patients with Pneumocystis pneumonia often develop respiratory failure after entry into medical care, and one mechanism for this deterioration may be increased alveolar epithelial cell injury. In vitro, we previously demonstrated that Pneumocystis is not cytotoxic for alveolar epithelial cells. In vivo, however, infection with Pneumocystis could increase susceptibility to injury by stressors that, alone, would be sublethal. We examined transient exposure to hyperoxia as a prototypical stress that does cause mortality in normal mice. Mice were depleted of CD4+ T cells and inoculated intratracheally with Pneumocystis. Control mice were depleted of CD4+ T cells but did not receive Pneumocystis. After 4 weeks, mice were maintained in normoxia, were exposed to hyperoxia for 4 days, or were exposed to hyperoxia for 4 days followed by return to normoxia. CD4-depleted mice with Pneumocystis pneumonia demonstrated significant mortality after transient exposure to hyperoxia, while all uninfected control mice survived this stress. We determined that organism burdens were not different. However, infected mice exposed to hyperoxia and then returned to normoxia demonstrated significant increases in inflammatory cell accumulation and lung cell apoptosis. We conclude that Pneumocystis pneumonia leads to increased mortality following a normally sublethal hyperoxic insult, accompanied by alveolar epithelial cell injury and increased pulmonary inflammation.
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Affiliation(s)
- James M Beck
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School Medical Service, Department of Veterans Affairs Medical Center, 2215 Fuller Road, Ann Arbor, MI 48105, USA.
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44
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Beck JM, Blackmon MB, Rose CM, Kimzey SL, Preston AM, Green JM. T cell costimulatory molecule function determines susceptibility to infection with Pneumocystis carinii in mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:1969-77. [PMID: 12902500 DOI: 10.4049/jimmunol.171.4.1969] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Loss of T cell number and function during HIV infection or secondary to pharmacologic immunosuppression renders individuals susceptible to opportunistic infections, including Pneumocystis carinii pneumonia. Because costimulatory receptors are critical for optimal T cell function, we hypothesized that these proteins would regulate susceptibility to opportunistic infections. We found that despite normal T cell numbers, mice deficient in the costimulatory molecules CD2 and CD28 spontaneously developed P. carinii pneumonia. In experiments using intratracheal injection of P. carinii organisms to induce infection, the loss of CD28 alone was sufficient to render mice susceptible to acute infection; however, the organism was eventually cleared. Examination of inflammatory responses to P. carinii revealed that mice deficient in both CD2 and CD28 accumulated CD8(+) T cells in their lungs in response to infection and demonstrated markedly reduced specific Ab titers. Analysis of cytokine profiles suggested that regulation of IL-10 and IL-15 may be important elements of the response to this pathogen. Thus, costimulatory molecule function is critical in determining the initial susceptibility to infection with P. carinii. Analysis of immunologic responses in these mice may provide important insights into the defects that render individuals susceptible to opportunistic infection, and provide opportunities for novel immunologically based therapies.
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Affiliation(s)
- James M Beck
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
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45
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Patil SP, Board KF, Lebedeva IP, Norris KA. Immune Responses to Pneumocystis Colonization and Infection in a Simian Model of AIDS. J Eukaryot Microbiol 2003; 50 Suppl:661-2. [PMID: 14736208 DOI: 10.1111/j.1550-7408.2003.tb00675.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Sangita P Patil
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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46
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Baumgartner R, Durant PJ, van Gessel Y, Chattopadhyay S, Beswick RL, Tadaki DK, Lasbury ME, Lee CH, Perrin PJ, Lee KP. Evidence for the requirement of T cell costimulation in the pathogenesis of natural Pneumocystis carinii pulmonary infection. Microb Pathog 2002; 33:193-201. [PMID: 12473434 DOI: 10.1006/mpat.2002.0528] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pneumocystis carinii pneumonia (PCP) is a frequent and serious opportunistic infection in immunocompromized patients. Although the pathogenesis of PCP-mediated lung injury is poorly understood, a central involvement of host inflammatory responses has been implicated. We have found that while the loss of specific T cell costimulatory signals increases susceptibility to the spontaneous pneumocystis infection, PCP-induced pulmonary injury (and subsequent morbidity and mortality) involves other intact costimulatory pathways. Mice that are genetically deficient for the costimulatory receptor CD154 (CD154 knockout (ko) mice) spontaneously developed PCP, consistent with the increased susceptibility of X-linked hyper IgM syndrome patients (caused by CD154 gene mutations) to P. carinii infection. In these mice PCP was manifested by progressive weight loss, dyspnea and death. In contrast, CD154 ko mice also genetically lacking ICAM1 (CD154 koxICAM1 ko) or CD28 (CD154 koxCD28 ko) costimulatory receptors had later onset of weight loss and significantly prolonged survival. Although onset of infection and age-matched P. carinii organism burden were equivalent, the CD154 single knockout mice had evidence of greater pulmonary inflammation vs. the double ko's. These findings suggest that costimulation-dependent T cell-mediated inflammation plays an important role in both susceptibility to and pathogenesis of PCP, and may identify potential molecular targets for novel immunomodulatory treatment approaches.
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47
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Steele C, Zheng M, Young E, Marrero L, Shellito JE, Kolls JK. Increased host resistance against Pneumocystis carinii pneumonia in gammadelta T-cell-deficient mice: protective role of gamma interferon and CD8(+) T cells. Infect Immun 2002; 70:5208-15. [PMID: 12183572 PMCID: PMC128275 DOI: 10.1128/iai.70.9.5208-5215.2002] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although a clear relationship between alphabeta T-cell receptor-positive (alphabeta-TCR(+)) CD4(+) T cells and susceptibility to Pneumocystis carinii infection exists, the role of other T-cell subsets is less clearly defined. Previous studies have shown that gammadelta-TCR(+) T cells infiltrate into the lung during P. carinii pneumonia. Therefore, the present study examined the role of gammadelta-TCR(+) T cells in host defense against P. carinii pneumonia. C57BL/6 (control) and B6.129P2-Tcrd(tm1Mom) (gammadelta-TCR(+) T-cell-deficient) mice were inoculated intratracheally with P. carinii. At specific time points, mice were sacrificed and analyzed for P. carinii burden, T-cell subsets, and cytokine levels in lung tissue. Analysis of P. carinii burden showed a more rapid and complete resolution of infection in gammadelta-TCR(+) T-cell-deficient mice than in C57BL/6 controls. This augmented resolution was associated with elevated gamma interferon (IFN-gamma) levels in bronchoalveolar lavage fluid predominantly produced by CD8(+) T cells, as well as an increased recruitment of CD8(+) T cells in general. In separate experiments, neutralization of IFN-gamma or depletion of CD8(+) T cells early during infection abolished the augmented resolution previously observed in gammadelta-TCR(+) T-cell-deficient mice. These results show that the presence of gammadelta-TCR(+) T cells modulates host susceptibility to P. carinii pneumonia through interactions with pulmonary CD8(+) T cells and tissue production of IFN-gamma.
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Affiliation(s)
- Chad Steele
- Section of Pulmonary and Critical Care and Gene Therapy Program, School of Medicine, Louisiana State University Health Sciences Center, New Orleans 70112, USA
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Croix DA, Board K, Capuano S, Murphey-Corb M, Haidaris CG, Flynn JL, Reinhart T, Norris KA. Alterations in T lymphocyte profiles of bronchoalveolar lavage fluid from SIV- and Pneumocystis carinii-coinfected rhesus macaques. AIDS Res Hum Retroviruses 2002; 18:391-401. [PMID: 11897041 DOI: 10.1089/088922202753519179] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The goal of this study was to examine SIV- and Pneumocystis carinii-coinfected rhesus macaques as a model of P. carinii infection in HIV-seropositive humans. The influence of P. carinii infection on the cellular composition of bronchoalveolar lavage (BAL) fluid from SIV-infected and normal rhesus macaques was examined by flow cytometric analysis and polymerase chain reaction (PCR). BAL fluid from SIV- and P. carinii coinfected macaques showed a substantial T lymphocyte influx composed of more than 90% CD8+ T cells. These results are in contrast to BAL fluid from SIV-infected macaques with no detectable P. carinii-specific PCR product, where CD4+ T cells were present in significant numbers and the CD8+ T cell population was less than 70% of total CD3+ lymphocytes. We observed no significant differences in peripheral blood CD4+ or CD8+ T cell levels in the SIV-infected animals, regardless of P. carinii status, indicating that the CD8+ T cell infiltration in the lungs of the P. carinii-positive animals was likely the result of P. carinii infection. These results demonstrate that although peripheral blood CD4+ T cell levels are predictive of susceptibility to P. carinii infection in this model, the levels are not reflective of the T cell profile in the lung during SIV and P. carinii coinfection. The SIV- and P. carinii-coinfected macaques showed a spectrum of lung disease severity that was histologically similar to human P. carinii pneumonia (PCP). Interestingly, even mild P. carinii infection was sufficient to alter the normal CD4+/CD8+ T cell profiles in the lungs of SIV-infected rhesus macaques. These results are similar to immunologic findings in human AIDS-associated PCP and support the usefulness of this model in the study of immune responses to P. carinii.
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Affiliation(s)
- Denise A Croix
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
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49
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Beck JM, Rosen MJ, Peavy HH. Pulmonary complications of HIV infection. Report of the Fourth NHLBI Workshop. Am J Respir Crit Care Med 2001; 164:2120-6. [PMID: 11739145 DOI: 10.1164/ajrccm.164.11.2102047] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
MESH Headings
- AIDS-Related Opportunistic Infections/epidemiology
- AIDS-Related Opportunistic Infections/virology
- Adult
- Antiretroviral Therapy, Highly Active
- Child
- HIV Infections/complications
- HIV Infections/drug therapy
- HIV Infections/epidemiology
- HIV Infections/immunology
- Humans
- Incidence
- Lung Diseases/epidemiology
- Lung Diseases/virology
- Lung Diseases, Fungal/epidemiology
- Lung Diseases, Fungal/virology
- Lung Neoplasms/epidemiology
- Lung Neoplasms/virology
- Pneumonia, Bacterial/epidemiology
- Pneumonia, Bacterial/virology
- Pneumonia, Pneumocystis/epidemiology
- Pneumonia, Pneumocystis/virology
- Pneumonia, Viral/epidemiology
- Pneumonia, Viral/virology
- Pulmonary Disease, Chronic Obstructive/epidemiology
- Pulmonary Disease, Chronic Obstructive/virology
- Tuberculosis, Pulmonary/epidemiology
- Tuberculosis, Pulmonary/virology
- United States/epidemiology
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Affiliation(s)
- J M Beck
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, and Veterans Affairs Medical Center, Ann Arbor, Michigan 48105-2300, USA. jamebeck@umich
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50
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Fishman JA. Prevention of infection caused by Pneumocystis carinii in transplant recipients. Clin Infect Dis 2001; 33:1397-405. [PMID: 11565082 DOI: 10.1086/323129] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2001] [Revised: 06/05/2001] [Indexed: 11/04/2022] Open
Abstract
Pneumocystis carinii remains an important pathogen in patients who undergo solid-organ and hematopoietic transplantation. Infection results from reactivation of latent infection and via de novo acquisition of infection from environmental sources. The risk of infection depends on the intensity and duration of immunosuppression and underlying immune deficits. The risk is greatest after lung transplants, in individuals with invasive cytomegalovirus disease, during intensive immunosuppression for allograft rejection, and during periods of neutropenia. Prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMZ) prevents many opportunistic infections, including infection with P. carinii, Toxoplasma gondii, and community-acquired respiratory, gastrointestinal, and urinary tract pathogens. Intolerance of TMP-SMZ is common; desensitization is useful less often in transplant patients than in patients with AIDS. Alternative agents provide a narrower spectrum of protection than does TMP-SMZ and less adequate protection against Pneumocystis species. Clinically, the diagnosis of breakthrough Pneumocystis pneumonia often requires invasive procedures. Strategies for the prevention of Pneumocystis infection must be individualized on the basis of a stratification of risk for each patient.
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Affiliation(s)
- J A Fishman
- Infectious Disease Division and Transplantation Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
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