1
|
Fonseca A, Szysz M, Ly HT, Cordeiro C, Sepúlveda N. IgG Antibody Responses to Epstein-Barr Virus in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Their Effective Potential for Disease Diagnosis and Pathological Antigenic Mimicry. MEDICINA (KAUNAS, LITHUANIA) 2024; 60:161. [PMID: 38256421 PMCID: PMC10820613 DOI: 10.3390/medicina60010161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/02/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024]
Abstract
Background and Objectives: The diagnosis and pathology of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) remain under debate. However, there is a growing body of evidence for an autoimmune component in ME/CFS caused by the Epstein-Barr virus (EBV) and other viral infections. Materials and Methods: In this work, we analyzed a large public dataset on the IgG antibodies to 3054 EBV peptides to understand whether these immune responses could help diagnose patients and trigger pathological autoimmunity; we used healthy controls (HCs) as a comparator cohort. Subsequently, we aimed at predicting the disease status of the study participants using a super learner algorithm targeting an accuracy of 85% when splitting data into train and test datasets. Results: When we compared the data of all ME/CFS patients or the data of a subgroup of those patients with non-infectious or unknown disease triggers to the data of the HC, we could not find an antibody-based classifier that would meet the desired accuracy in the test dataset. However, we could identify a 26-antibody classifier that could distinguish ME/CFS patients with an infectious disease trigger from the HCs with 100% and 90% accuracies in the train and test sets, respectively. We finally performed a bioinformatic analysis of the EBV peptides associated with these 26 antibodies. We found no correlation between the importance metric of the selected antibodies in the classifier and the maximal sequence homology between human proteins and each EBV peptide recognized by these antibodies. Conclusions: In conclusion, these 26 antibodies against EBV have an effective potential for disease diagnosis in a subset of patients. However, the peptides associated with these antibodies are less likely to induce autoimmune B-cell responses that could explain the pathogenesis of ME/CFS.
Collapse
Affiliation(s)
- André Fonseca
- Faculty of Sciences and Technology, University of Algarve, 8005-139 Faro, Portugal; (A.F.); (C.C.)
- CEAUL—Centre of Statistics and its Applications, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Mateusz Szysz
- Faculty of Mathematics & Information Science, Warsaw University of Technology, 00-662 Warsaw, Poland; (M.S.); (H.T.L.)
| | - Hoang Thien Ly
- Faculty of Mathematics & Information Science, Warsaw University of Technology, 00-662 Warsaw, Poland; (M.S.); (H.T.L.)
| | - Clara Cordeiro
- Faculty of Sciences and Technology, University of Algarve, 8005-139 Faro, Portugal; (A.F.); (C.C.)
- CEAUL—Centre of Statistics and its Applications, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Nuno Sepúlveda
- CEAUL—Centre of Statistics and its Applications, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
- Faculty of Mathematics & Information Science, Warsaw University of Technology, 00-662 Warsaw, Poland; (M.S.); (H.T.L.)
| |
Collapse
|
2
|
Mukhopadhyay D, Arranz-Solís D, Saeij JPJ. Influence of the Host and Parasite Strain on the Immune Response During Toxoplasma Infection. Front Cell Infect Microbiol 2020; 10:580425. [PMID: 33178630 PMCID: PMC7593385 DOI: 10.3389/fcimb.2020.580425] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/11/2020] [Indexed: 01/02/2023] Open
Abstract
Toxoplasma gondii is an exceptionally successful parasite that infects a very broad host range, including humans, across the globe. The outcome of infection differs remarkably between hosts, ranging from acute death to sterile infection. These differential disease patterns are strongly influenced by both host- and parasite-specific genetic factors. In this review, we discuss how the clinical outcome of toxoplasmosis varies between hosts and the role of different immune genes and parasite virulence factors, with a special emphasis on Toxoplasma-induced ileitis and encephalitis.
Collapse
Affiliation(s)
- Debanjan Mukhopadhyay
- Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - David Arranz-Solís
- Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Jeroen P J Saeij
- Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| |
Collapse
|
3
|
Abstract
Early electron microscopy studies revealed the elaborate cellular features that define the unique adaptations of apicomplexan parasites. Among these were bulbous rhoptry (ROP) organelles and small, dense granules (GRAs), both of which are secreted during invasion of host cells. These early morphological studies were followed by the exploration of the cellular contents of these secretory organelles, revealing them to be comprised of highly divergent protein families with few conserved domains or predicted functions. In parallel, studies on host-pathogen interactions identified many host signaling pathways that were mysteriously altered by infection. It was only with the advent of forward and reverse genetic strategies that the connections between individual parasite effectors and the specific host pathways that they targeted finally became clear. The current repertoire of parasite effectors includes ROP kinases and pseudokinases that are secreted during invasion and that block host immune pathways. Similarly, many secretory GRA proteins alter host gene expression by activating host transcription factors, through modification of chromatin, or by inducing small noncoding RNAs. These effectors highlight novel mechanisms by which T. gondii has learned to harness host signaling to favor intracellular survival and will guide future studies designed to uncover the additional complexity of this intricate host-pathogen interaction.
Collapse
|
4
|
Abstract
Toxoplasmosis is the clinical and pathological consequence of acute infection with the obligate intracellular apicomplexan parasite Toxoplasma gondii. Symptoms result from tissue destruction that accompanies lytic parasite growth. This review updates current understanding of the host cell invasion, parasite replication, and eventual egress that constitute the lytic cycle, as well as the ways T. gondii manipulates host cells to ensure its survival. Since the publication of a previous iteration of this review 15 years ago, important advances have been made in our molecular understanding of parasite growth and mechanisms of host cell egress, and knowledge of the parasite's manipulation of the host has rapidly progressed. Here we cover molecular advances and current conceptual frameworks that include each of these topics, with an eye to what may be known 15 years from now.
Collapse
Affiliation(s)
- Ira J Blader
- Department of Microbiology and Immunology, University at Buffalo, Buffalo, New York 14127;
| | - Bradley I Coleman
- Department of Biology, Boston College, Chestnut Hill, Massachusetts 02467; , ,
| | - Chun-Ti Chen
- Department of Biology, Boston College, Chestnut Hill, Massachusetts 02467; , ,
| | - Marc-Jan Gubbels
- Department of Biology, Boston College, Chestnut Hill, Massachusetts 02467; , ,
| |
Collapse
|
5
|
Abstract
PURPOSE OF REVIEW Ischemia and reperfusion injuries occur in multiple clinical settings and contribute to organ dysfunction/failures. Despite the innate inflammatory immune nature, T cells that are critically involved in the pathogenesis of ischemia reperfusion injury (IRI), include not only CD4+ T cells, but also CD8+ and γδT cells. This review focuses on questions of how putative Ag-specific T cells are involved, which include whether they function in an Ag-dependent manner; how they function, cytokine-mediated or costimulatory molecule-mediated mechanisms; and whether different T-cell subsets, Th1, Th17, regulatory T cell (Treg), are all involved and play distinctive roles? RECENT FINDINGS Specific T-cell populations, such as effector memory CD4 T cells, promote inflammatory immune activation by ischemia reperfusion independent of their adaptive properties, that is Ag-independently. They function by secreting cytokines and expressing costimulatory molecules to either promote or inhibit innate immune activation, or facilitate tissue repair/homeostasis, as exemplified by Th1, Th17 or Th2, Treg cells, respectively. SUMMARY T-cell-targeted therapies need to be refined with strategies to maximally eliminate the proinflammatory but spare the anti-inflammatory/immune regulatory properties of T cells, for future clinical application to ameliorate IRI.
Collapse
|
6
|
The protein kinase double-stranded RNA-dependent (PKR) enhances protection against disease cause by a non-viral pathogen. PLoS Pathog 2013; 9:e1003557. [PMID: 23990781 PMCID: PMC3749959 DOI: 10.1371/journal.ppat.1003557] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 07/01/2013] [Indexed: 01/08/2023] Open
Abstract
PKR is well characterized for its function in antiviral immunity. Using Toxoplasma gondii, we examined if PKR promotes resistance to disease caused by a non-viral pathogen. PKR(-/-) mice infected with T. gondii exhibited higher parasite load and worsened histopathology in the eye and brain compared to wild-type controls. Susceptibility to toxoplasmosis was not due to defective expression of IFN-γ, TNF-α, NOS2 or IL-6 in the retina and brain, differences in IL-10 expression in these organs or to impaired induction of T. gondii-reactive T cells. While macrophages/microglia with defective PKR signaling exhibited unimpaired anti-T. gondii activity in response to IFN-γ/TNF-α, these cells were unable to kill the parasite in response to CD40 stimulation. The TRAF6 binding site of CD40, but not the TRAF2,3 binding sites, was required for PKR phosphorylation in response to CD40 ligation in macrophages. TRAF6 co-immunoprecipitated with PKR upon CD40 ligation. TRAF6-PKR interaction appeared to be indirect, since TRAF6 co-immunoprecipitated with TRAF2 and TRAF2 co-immunoprecipitated with PKR, and deficiency of TRAF2 inhibited TRAF6-PKR co-immunoprecipitation as well as PKR phosphorylation induced by CD40 ligation. PKR was required for stimulation of autophagy, accumulation the autophagy molecule LC3 around the parasite, vacuole-lysosomal fusion and killing of T. gondii in CD40-activated macrophages and microglia. Thus, our findings identified PKR as a mediator of anti-microbial activity and promoter of protection against disease caused by a non-viral pathogen, revealed that PKR is activated by CD40 via TRAF6 and TRAF2, and positioned PKR as a link between CD40-TRAF signaling and stimulation of the autophagy pathway.
Collapse
|
7
|
CD40 induces anti-Toxoplasma gondii activity in nonhematopoietic cells dependent on autophagy proteins. Infect Immun 2013; 81:2002-11. [PMID: 23509150 DOI: 10.1128/iai.01145-12] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Toxoplasma gondii infects both hematopoietic and nonhematopoietic cells and can cause cerebral and ocular toxoplasmosis, as a result of either congenital or postnatally acquired infections. Host protection likely acts at both cellular levels to control the parasite. CD40 is a key factor for protection against cerebral and ocular toxoplasmosis. We determined if CD40 induces anti-T. gondii activity at the level of nonhematopoietic cells. Engagement of CD40 on various endothelial cells including human microvascular brain endothelial cells, human umbilical vein endothelial cells, and a mouse endothelial cell line as well as human and mouse retinal pigment epithelial cells resulted in killing of T. gondii. CD40 stimulation increased expression of the autophagy proteins Beclin 1 and LC3 II, enhanced autophagy flux, and led to recruitment of LC3 around the parasite. The late endosomal/lysosomal marker LAMP-1 accumulated around the parasite in CD40-stimulated cells. This was accompanied by killing of T. gondii dependent on lysosomal enzymes. Accumulation of LAMP-1 and killing of T. gondii were dependent on the autophagy proteins Beclin 1 and Atg7. Together, these studies revealed that CD40 induces toxoplasmacidal activity in various nonhematopoietic cells dependent on proteins of the autophagy machinery.
Collapse
|
8
|
Egan CE, Cohen SB, Denkers EY. Insights into inflammatory bowel disease using Toxoplasma gondii as an infectious trigger. Immunol Cell Biol 2011; 90:668-75. [PMID: 22064707 DOI: 10.1038/icb.2011.93] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Oral infection of certain inbred mouse strains with the protozoan Toxoplasma gondii triggers inflammatory pathology resembling lesions seen during human inflammatory bowel disease, in particular Crohn's disease (CD). Damage triggered by the parasite is largely localized to the distal portion of the small intestine, and as such is one of only a few models for ileal inflammation. This is important because ileal involvement is a characteristic of CD in over two-thirds of patients. The disease induced by Toxoplasma is mediated by Th1 cells and the cytokines tumor necrosis factor-α and interferon-γ. Inflammation is dependent upon IL-23, also identified by genome-wide association studies as a risk factor in CD. Development of lesions is concomitant with emergence of E. coli that display enhanced adhesion to the intestinal epithelium and subepithelial translocation. Furthermore, depletion of gut flora renders mice resistant to Toxoplasma-triggered ileitis. Recent findings suggest complex CCR2-dependent interactions between lamina propria T cells and intraepithelial lymphocytes in fueling proinflammatory pathology in the intestine. The advantage of the Toxoplasma model is that disease develops rapidly (within 7-10 days of infection) and can be induced in immunodeficient mice by adoptive transfer of mucosal T cells from infected donors. We propose that Toxoplasma acts as a trigger setting into motion a series of events culminating in loss of tolerance in the intestine and emergence of pathogenic T cell effectors. The Toxoplasma trigger model is providing new leaps in our understanding of immunity in the intestine.
Collapse
Affiliation(s)
- Charlotte E Egan
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | | | | |
Collapse
|
9
|
Kolodziej H. Antimicrobial, Antiviral and Immunomodulatory Activity Studies of Pelargonium sidoides (EPs ® 7630) in the Context of Health Promotion. Pharmaceuticals (Basel) 2011; 4:1295-1314. [PMID: 27721327 PMCID: PMC4060126 DOI: 10.3390/ph4101295] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 09/20/2011] [Accepted: 09/29/2011] [Indexed: 11/20/2022] Open
Abstract
Pelargonium species contribute significantly to the health care of a large population in the Southern African region, as part of a long-standing medical system intimately linked to traditional healing practices. Most notably, extracts of the roots of P. sidoides have commonly been applied for the treatment of dysentery and diarrhoea but only occasionally for respiratory complaints. Clinical trials have shown that a modern aqueous-ethanolic formulation of P. sidoides extracts (EPs® 7630) is an efficacious treatment for disorders of the respiratory tract, for example bronchitis and sinusitis. It should be noted that EPs® 7630 is the most widely investigated extract and therefore is the focus of this review. In order to provide a rationale for its therapeutic activity extracts have been evaluated for antibacterial activity and for their effects on non-specific immune functions. Only moderate direct antibacterial capabilities against a spectrum of bacteria, including Mycobacteria strains, have been noted. In contrast, a large body of in vitro studies has provided convincing evidence for an anti-infective principle associated with activation of the non-specific immune system. Interestingly, significant inhibition of interaction between bacteria and host cells, a key to the pathogenesis of respiratory tract infections, has emerged from recent studies. In addition, antiviral effects have been demonstrated, including inhibition of the replication of respiratory viruses and the enzymes haemagglutinin and neuraminidase. Besides, an increase of cilliary beat frequency of respiratory cells may contribute to the beneficial effects of P. sidoides extracts. This example provides a compelling argument for continuing the exploration of Nature and traditional medical systems as a source of therapeutically useful herbal medicines.
Collapse
Affiliation(s)
- Herbert Kolodziej
- Institute of Pharmacy, Pharmaceutical Biology, Freie Universität Berlin, Koenigin-Luise-Str. 2+4, Berlin 14195, Germany.
| |
Collapse
|
10
|
Portillo JAC, Okenka G, Reed E, Subauste A, Van Grol J, Gentil K, Komatsu M, Tanaka K, Landreth G, Levine B, Subauste CS. The CD40-autophagy pathway is needed for host protection despite IFN-Γ-dependent immunity and CD40 induces autophagy via control of P21 levels. PLoS One 2010; 5:e14472. [PMID: 21217818 PMCID: PMC3013095 DOI: 10.1371/journal.pone.0014472] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Accepted: 12/03/2010] [Indexed: 02/02/2023] Open
Abstract
Autophagy degrades pathogens in vitro. The autophagy gene Atg5 has been reported to be required for IFN-γ-dependent host protection in vivo. However, these protective effects occur independently of autophagosome formation. Thus, the in vivo role of classic autophagy in protection conferred by adaptive immunity and how adaptive immunity triggers autophagy are incompletely understood. Employing biochemical, genetic and morphological studies, we found that CD40 upregulates the autophagy molecule Beclin 1 in microglia and triggers killing of Toxoplasma gondii dependent on the autophagy machinery. Infected CD40(-/-) mice failed to upregulate Beclin 1 in microglia/macrophages in vivo. Autophagy-deficient Beclin 1(+/-) mice, mice with deficiency of the autophagy protein Atg7 targeted to microglia/macrophages as well as CD40(-/-) mice exhibited impaired killing of T. gondii and were susceptible to cerebral and ocular toxoplasmosis. Susceptibility to toxoplasmosis occurred despite upregulation of IFN-γ, TNF-α and NOS2, preservation of IFN-γ-induced microglia/macrophage anti-T. gondii activity and the generation of anti-T. gondii T cell immunity. CD40 upregulated Beclin 1 and triggered killing of T. gondii by decreasing protein levels of p21, a molecule that degrades Beclin 1. These studies identified CD40-p21-Beclin 1 as a pathway by which adaptive immunity stimulates autophagy. In addition, they support that autophagy is a mechanism through which CD40-dependent immunity mediates in vivo protection and that the CD40-autophagic machinery is needed for host resistance despite IFN-γ.
Collapse
Affiliation(s)
- Jose-Andres C. Portillo
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Genevieve Okenka
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Erin Reed
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Angela Subauste
- Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan, United States of America
| | - Jennifer Van Grol
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Katrin Gentil
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Masaaki Komatsu
- Laboratory for Frontier Science, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Keiji Tanaka
- Laboratory for Frontier Science, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Gary Landreth
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Beth Levine
- Department of Internal Medicine, Department of Microbiology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Carlos S. Subauste
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- * E-mail:
| |
Collapse
|
11
|
Van Grol J, Subauste C, Andrade RM, Fujinaga K, Nelson J, Subauste CS. HIV-1 inhibits autophagy in bystander macrophage/monocytic cells through Src-Akt and STAT3. PLoS One 2010; 5:e11733. [PMID: 20661303 PMCID: PMC2908694 DOI: 10.1371/journal.pone.0011733] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Accepted: 06/16/2010] [Indexed: 11/18/2022] Open
Abstract
Autophagy is a homeostatic mechanism of lysosomal degradation. Defective autophagy has been linked to various disorders such as impaired control of pathogens and neurodegeneration. Autophagy is regulated by a complex array of signaling pathways that act upstream of autophagy proteins. Little is known about the role of altered regulatory signaling in disorders associated with defective autophagy. In particular, it is not known if pathogens inhibit autophagy by modulation of upstream regulatory pathways. Cells infected with HIV-1 blocked rapamycin-induced autophagy and CD40-induced autophagic killing of Toxoplasma gondii in bystander (non-HIV-1 infected) macrophage/monocytic cells. Blockade of autophagy was dependent on Src-Akt and STAT3 triggered by HIV-1 Tat and IL-10. Neutralization of the upstream receptors VEGFR, beta-integrin or CXCR4, as well as of HIV-1 Tat or IL-10 restored autophagy in macrophage/monocytic cells exposed to HIV-1-infected cells. Defective autophagic killing of T. gondii was detected in monocyte-derived macrophages from a subset of HIV-1(+) patients. This defect was also reverted by neutralization of Tat or IL-10. These studies revealed that a pathogen can impair autophagy in non-infected cells by activating counter-regulatory pathways. The fact that pharmacologic manipulation of cell signaling restored autophagy in cells exposed to HIV-1-infected cells raises the possibility of therapeutic manipulation of cell signaling to restore autophagy in HIV-1 infection.
Collapse
Affiliation(s)
- Jennifer Van Grol
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Cecilia Subauste
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Rosa M. Andrade
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Koh Fujinaga
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Julie Nelson
- Center for AIDS Research, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Carlos S. Subauste
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- * E-mail:
| |
Collapse
|
12
|
Subauste CS. CD40, autophagy and Toxoplasma gondii. Mem Inst Oswaldo Cruz 2010; 104:267-72. [PMID: 19430652 DOI: 10.1590/s0074-02762009000200020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Accepted: 12/03/2008] [Indexed: 01/10/2023] Open
Abstract
Toxoplasma gondii represents a pathogen that survives within host cells by preventing the endosomal-lysosomal compartments from fusing with the parasitophorous vacuoles. The dogma had been that the non-fusogenic nature of these vacuoles is irreversible. Recent studies revealed that this dogma is not correct. Cell-mediated immunity through CD40 re-routes the parasitophorous vacuoles to the lysosomal compartment by a process called autophagy. Autophagosome formation around the parasitophorous vacuole results in killing of the T. gondii. CD40-induced autophagy likely contributes to resistance against T. gondii particularly in neural tissue.
Collapse
Affiliation(s)
- Carlos S Subauste
- Department of Pathology, Division of Infectious Diseases and HIV Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
| |
Collapse
|
13
|
Abstract
A decisive outcome during host-pathogen interaction is governed by whether pathogen-containing vacuoles fuse with lysosomes. Fusion with lysosomes typically kills microbes. Toxoplasma gondii represents a classical example of an intracellular pathogen that survives within host cells by preventing the endosomal-lysosomal compartments from fusing with the vacuoles that contain the pathogen. Thus, T. gondii provides an excellent model to determine if the immune system can target a pathogen for lysosomal degradation. CD40, a major regulator of cell-mediated immunity, activates macrophages to kill T. gondii through a process that requires recruitment of autophagosomes around the parasitophorous vacuole, leading to lysosomal degradation of the parasite. These studies demonstrate that cell-mediated immunity can activate autophagy to kill a pathogen. CD40-induced autophagy likely contributes to resistance against T. gondii, particularly in neural tissues, the main sites affected by this pathogen.
Collapse
|
14
|
Jongert E, Lemiere A, Van Ginderachter J, De Craeye S, Huygen K, D'Souza S. Functional characterization of in vivo effector CD4(+) and CD8(+) T cell responses in acute Toxoplasmosis: an interplay of IFN-gamma and cytolytic T cells. Vaccine 2010; 28:2556-64. [PMID: 20117266 DOI: 10.1016/j.vaccine.2010.01.031] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2009] [Revised: 12/26/2009] [Accepted: 01/16/2010] [Indexed: 01/05/2023]
Abstract
Development of prophylactic vaccines against Toxoplasma gondii is based on the observation that latently infected subjects are protected against secondary infection during pregnancy. Cocktail DNA vaccines have been shown to provide high resistance to parasite challenge, and latently infected mice are protected against acute disease. In order to characterize the associated Th1 cellular immune responses in vivo, we used H2-K(k) bone marrow macrophage cell lines constitutively expressing T. gondii GRA1, GRA7 or ROP2 antigens, for the in vivo characterization of antigen-specific T cells in an antigenic challenge model, and as target cells in an in vivo CTL assay. In latently infected C3H/HeN mice, CD4(+) and CD8(+) T cells were recruited to the peritoneal cavity after i.p. challenge with these syngeneic cell lines. GRA1 and GRA7-specific T cells from infected mice were IFN-gamma(+) FasL(-) CD107(-). No IFN-gamma or lytic markers were observed against ROP2. In cocktail DNA vaccinated C3H/HeN mice, the response was restricted to GRA1-specific CD8(+) IFN-gamma(-) FasL(-) CD107(+) T cells. Target cells expressing GRA1 and GRA7, but not ROP2, were efficiently killed in an in vivo CTL assay in latently infected mice, while in DNA vaccinated mice only lysis of GRA1 expressing target cells was observed. Both forms of immunization, DNA vaccination and latent infection, completely protected mice against acute Toxoplasmosis. The results obtained in this work suggest that distinct in vivo cytolytic effector mechanisms are at work in DNA vaccinated and latently infected mice, but both converge to protect against acute toxoplasmosis.
Collapse
Affiliation(s)
- Erik Jongert
- Laboratory for Toxoplasmosis, Pasteur Institute of Brussels, Brussels, Belgium.
| | | | | | | | | | | |
Collapse
|
15
|
Shen X, Wang Y, Gao F, Ren F, Busuttil RW, Kupiec-Weglinski JW, Zhai Y. CD4 T cells promote tissue inflammation via CD40 signaling without de novo activation in a murine model of liver ischemia/reperfusion injury. Hepatology 2009; 50:1537-46. [PMID: 19670423 PMCID: PMC2805281 DOI: 10.1002/hep.23153] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
UNLABELLED Although the role of CD4 T cells in tissue inflammation and organ injury resulting from ischemia and reperfusion injury (IRI) has been well documented, it remains unclear how CD4 T cells are activated and function in the absence of a specific antigen (Ag). We used a murine liver warm IRI model to determine first whether de novo Ag-specific CD4 T cell activation was required and then what its functional mechanism was. The critical role of CD4 T cells in liver immune activation against ischemia and reperfusion (IR) was confirmed in CD4 knockout mice and CD4 depleted wild-type mice. Interestingly, the inhibition of CD4 T cell activation without target cell depletion failed to protect livers against IRI, and this suggested that T cells function in liver IRI without Ag-specific de novo activation. To dissect the T cell functional mechanism, we found that CD154 blockade, but not interferon gamma (IFN-gamma) neutralization, inhibited local immune activation and protected livers from IRI. Furthermore, agonist anti-CD40 antibodies restored liver IRI in otherwise protected CD4-deficient hosts. Finally, fluorescence-activated cell sorting analysis of liver CD4 T cells revealed the selective infiltration of effector cells, which constitutively expressed a higher level of CD154 in comparison with their peripheral counterparts. IR triggered a significant liver increase in CD40 expression but not CD154 expression, and macrophages responded to toll-like receptor 4 and type I IFN stimulation to up-regulate CD40 expression. CONCLUSION These novel findings provide evidence that CD4 T cells function in liver IRI via CD154 without de novo Ag-specific activation, and innate immunity-induced CD40 up-regulation may trigger the engagement of CD154-CD40 to facilitate tissue inflammation and injury.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Yuan Zhai
- Address correspondence to: Yuan Zhai, MD, PhD. Dumont-UCLA Transplant Center 77-120 CHS, 10833 Le Conte Ave, Los Angeles, CA 90095. Phone: (310) 825-9426; Fax: (310) 267-2367;
| |
Collapse
|
16
|
Abstract
The interaction between CD40 and CD154 regulates many aspects of cellular and humoral immunity. The CD40-CD154 pathway is important for resistance against a variety of parasites. Studies done with these pathogens have provided important insight into the various mechanisms by which this pathway enhances host protection, mechanisms by which pathogens subvert CD40 signaling, conditions in which the CD40-CD154 pathway promotes disease and on modulation of this pathway for immunotherapy.
Collapse
Affiliation(s)
- Carlos S Subauste
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, 11100 Euclid Avenue, Cleveland, OH 44106, USA.
| |
Collapse
|
17
|
cIAP1-dependent TRAF2 degradation regulates the differentiation of monocytes into macrophages and their response to CD40 ligand. Blood 2008; 113:175-85. [PMID: 18827186 DOI: 10.1182/blood-2008-02-137919] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Peripheral blood monocytes are plastic cells that migrate to tissues and differentiate into various cell types, including macrophages, dendritic cells, and osteoclasts. We have described the migration of cellular inhibitor of apoptosis protein 1 (cIAP1), a member of the IAP family of proteins, from the nucleus to the Golgi apparatus in monocytes undergoing differentiation into macrophages. Here we show that, once in the cytoplasm, cIAP1 is involved in the degradation of the adaptor protein tumor necrosis factor receptor-associated factor 2 (TRAF2) by the proteosomal machinery. Inhibition of cIAP1 prevents the decrease in TRAF2 expression that characterizes macrophage formation. We demonstrate that TRAF2 is initially required for macrophage differentiation as its silencing prevents Ikappa-Balpha degradation, nuclear factor-kappaB (NF-kappaB) p65 nuclear translocation, and the differentiation process. Then, we show that cIAP1-mediated degradation of TRAF2 allows the differentiation process to progress. This degradation is required for the macrophages to be fully functional as TRAF2 overexpression in differentiated cells decreases the c-Jun N-terminal kinase-mediated synthesis and the secretion of proinflammatory cytokines, such as interleukin-8 and monocyte chemoattractant protein 1 (MCP-1) in response to CD40 ligand. We conclude that TRAF2 expression and subsequent degradation are required for the differentiation of monocytes into fully functional macrophages.
Collapse
|
18
|
Jones LA, Anthony JP, Henriquez FL, Lyons RE, Nickdel MB, Carter KC, Alexander J, Roberts CW. Toll-like receptor-4-mediated macrophage activation is differentially regulated by progesterone via the glucocorticoid and progesterone receptors. Immunology 2008; 125:59-69. [PMID: 18373668 DOI: 10.1111/j.1365-2567.2008.02820.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Macrophage function has been demonstrated to be subject to modulation by progesterone. However, as this steroid hormone can act through the glucocorticoid receptor as well as the progesterone receptor, the mechanism of action has not been precisely characterized. To determine the mode of action, we compared the ability of progesterone, norgestrel (a synthetic progesterone-receptor-specific agonist) and dexamethasone (a synthetic glucocorticoid receptor agonist) to modulate macrophage function following stimulation of the Toll-like receptor-4 (TLR-4) ligand lipopolysaccharide (LPS). The results demonstrate that following stimulation of TLR-4 with LPS and cotreatment with either progesterone or dexamethasone, but not norgestrel, there is a significant reduction in nitric oxide (NO) production, indicating that this progesterone-mediated effect is through ligation of the glucocorticoid receptor. In contrast, LPS-induced interleukin-12 (IL-12) production could be downregulated by all three steroids, indicating that ligation by progesterone of either the glucocorticoid or the progesterone receptors or both could mediate this effect. While progesterone downmodulated NO-mediated killing of Leishmania donovani by activated macrophages in vitro, most probably via the glucocorticoid receptor, it had little effect on Toxoplasma gondii growth in these cells. This would suggest that progesterone-mediated increased susceptibility to T. gondii during pregnancy is more likely to be related to the ability of the hormone to downregulate IL-12 production and a type-1 response utilizing the progesterone as well as the glucocorticoid receptors.
Collapse
Affiliation(s)
- Leigh A Jones
- Strathclyde Institute for Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Leal FE, Cavazzana CL, de Andrade HF, Galisteo AJ, de Mendonça JS, Kallas EG. Toxoplasma gondii pneumonia in immunocompetent subjects: case report and review. Clin Infect Dis 2007; 44:e62-6. [PMID: 17304443 DOI: 10.1086/511871] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Accepted: 12/12/2006] [Indexed: 11/03/2022] Open
Abstract
Pulmonary toxoplasmosis is rare in immunocompetent subjects. Here, we describe a 41-year-old previously healthy male patient who presented to the emergency department of a hospital with a life-threatening case of pneumonia due to Toxoplasma gondii infection, which responded to specific therapy. Clinical and image-based findings overlap with those for atypical pneumonias, and toxoplasmosis should be considered in the differential diagnosis--especially if immunoglobulin M-specific antibodies are detected.
Collapse
Affiliation(s)
- Fabio Eudes Leal
- Hospital do Servidor Publico Estadual de São Paulo, São Paulo, SP, Brazil
| | | | | | | | | | | |
Collapse
|
20
|
Abstract
Primary immunodeficiencies are important disorders because they typically cause severe illness in affected patients. In addition, these diseases provide a unique glimpse at the underpinnings of the immune system in humans. Susceptibility to infections, including those caused by parasites, is a hallmark of these immune defects. Understanding the association between primary immunodeficiencies and parasitic infections will likely improve our grasp on the mechanisms of defense against these pathogens.
Collapse
Affiliation(s)
- C S Subauste
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0560, USA.
| |
Collapse
|
21
|
Buzoni-Gatel D, Werts C. Toxoplasma gondii and subversion of the immune system. Trends Parasitol 2006; 22:448-52. [PMID: 16904378 DOI: 10.1016/j.pt.2006.08.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 07/12/2006] [Accepted: 08/01/2006] [Indexed: 11/26/2022]
Abstract
Toxoplasma gondii is an intracellular obligate parasite that enters the host via the gastrointestinal tract. The parasite is able to evade or subvert the immune response of its host via various mechanisms. Here, we discuss a recent in vitro study by Eric Denkers and colleagues that focused on the modulation of gene transcription of host macrophages stimulated by lipopolysaccharide (LPS) following infection with T. gondii. The parasite was able to block the response of macrophages to LPS, a major immunostimulatory component of Gram negative bacteria, thus possibly avoiding the hyperinflammatory response of the host to gut microflora, among which Gram negative bacteria are abundant.
Collapse
|
22
|
Andrade RM, Wessendarp M, Gubbels MJ, Striepen B, Subauste CS. CD40 induces macrophage anti-Toxoplasma gondii activity by triggering autophagy-dependent fusion of pathogen-containing vacuoles and lysosomes. J Clin Invest 2006; 116:2366-77. [PMID: 16955139 PMCID: PMC1555650 DOI: 10.1172/jci28796] [Citation(s) in RCA: 232] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Accepted: 06/27/2006] [Indexed: 12/21/2022] Open
Abstract
Many intracellular pathogens, including Toxoplasma gondii, survive within macrophages by residing in vacuoles that avoid fusion with lysosomes. It is important to determine whether cell-mediated immunity can trigger macrophage antimicrobial activity by rerouting these vacuoles to lysosomes. We report that CD40 stimulation of human and mouse macrophages infected with T. gondii resulted in fusion of parasitophorous vacuoles and late endosomes/lysosomes. Vacuole/lysosome fusion took place even when CD40 was ligated after the formation of parasitophorous vacuoles. Genetic and pharmacological approaches that impaired phosphoinositide-3-class 3 (PIK3C3), Rab7, vacuolar ATPase, and lysosomal enzymes revealed that vacuole/lysosome fusion mediated antimicrobial activity induced by CD40. Ligation of CD40 caused colocalization of parasitophorous vacuoles and LC3, a marker of autophagy, which is a process that controls lysosomal degradation. Vacuole/lysosome fusion and antimicrobial activity were shown to be dependent on autophagy. Thus, cell-mediated immunity through CD40 stimulation can reroute an intracellular pathogen to the lysosomal compartment, resulting in macrophage antimicrobial activity.
Collapse
Affiliation(s)
- Rosa M. Andrade
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Matthew Wessendarp
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Marc-Jan Gubbels
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Boris Striepen
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Carlos S. Subauste
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| |
Collapse
|
23
|
Subauste CS, Wessendarp M. CD40 restrains in vivo growth of Toxoplasma gondii independently of gamma interferon. Infect Immun 2006; 74:1573-9. [PMID: 16495528 PMCID: PMC1418638 DOI: 10.1128/iai.74.3.1573-1579.2006] [Citation(s) in RCA: 32] [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
CD40-CD154 interaction is pivotal for resistance against numerous pathogens. However, it is not known if this pathway can also enhance in vivo resistance in gamma interferon (IFN-gamma)-deficient hosts. This is an important question because patients and mice with defects in type 1 cytokine response can control a variety of pathogens. While blockade of endogenous CD154 resulted in a remarkable increase in parasite load in IFN-gamma-/- mice infected with Toxoplasma gondii, in vivo administration of a stimulatory anti-CD40 monoclonal antibody markedly reduced parasite load. This latter effect took place even in T-cell-depleted mice and was accompanied by induction of macrophage toxoplasmacidal activity. CD40 stimulation restricted T. gondii replication independently of STAT1, p47 GTPases, and nitric oxide. In vivo CD40 ligation enhanced tumor necrosis factor alpha (TNF-alpha) production by T. gondii-infected macrophages. In addition, CD40 stimulation required the presence of TNF receptor 2 to reduce parasite load in vivo. These results suggest that CD40-CD154 interaction regulates IFN-gamma-independent mechanisms of host protection through induction of macrophage antimicrobial activity and modulation of TNF-alpha signaling.
Collapse
Affiliation(s)
- Carlos S Subauste
- Department of Internal Medicine, University of Cincinnati College of Medicine, P.O. Box 670560, Cincinnati, OH 45267-0560, USA.
| | | |
Collapse
|
24
|
Danese S, Sans M, Scaldaferri F, Sgambato A, Rutella S, Cittadini A, Piqué JM, Panes J, Katz JA, Gasbarrini A, Fiocchi C. TNF-alpha blockade down-regulates the CD40/CD40L pathway in the mucosal microcirculation: a novel anti-inflammatory mechanism of infliximab in Crohn's disease. THE JOURNAL OF IMMUNOLOGY 2006; 176:2617-24. [PMID: 16456024 DOI: 10.4049/jimmunol.176.4.2617] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The CD40/CD40 ligand (CD40L) pathway is involved in Crohn's disease (CD) pathogenesis. In the patients' circulation, soluble CD40L (sCD40L) levels are elevated and surface CD40L is increased in platelets and T cells, whereas in the intestine CD40 is overexpressed in the microvasculature and CD40L in platelets and T cells. The therapeutic effects of infliximab in CD are attributed to its systemic anti-TNF-alpha action, but because TNF-alpha modulates both CD40 and CD40L, we investigated whether infliximab affects the CD40/CD40L pathway in the intestine. Eighteen CD patients were evaluated before and after infliximab therapy. Plasma sCD40L was measured by ELISA and platelet and peripheral blood T cell (PBT) CD40L expression by flow cytometry. Microvascular CD40 and VCAM-1 expression were assessed in mucosal biopsies by immunohistochemistry and by flow cytometry in human intestinal microvascular endothelial cells (HIMEC). Cell cultures were performed in the presence and absence of infliximab. Infliximab treatment significantly reduced plasma sCD40L levels and eliminated CD40 and VCAM-1 from mucosal microvessels. In vitro infliximab prevented TNF-alpha-induced CD40 and VCAM-1 expression by HIMEC, and reduced PBT, but not platelet, surface CD40L expression and sCD40L release. In addition, infliximab decreased T cell-induced VCAM-1 expression in HIMEC by down-regulating CD40L in T cells and promoting T cells apoptosis. These findings point to a novel mechanism of action of infliximab, i.e., the disruption of CD40/CD40L-dependent cognate interactions between intestinal microvessels and T cells. Thus, in addition to neutralizing TNF-alpha and inducing T cell death, the therapeutic effects of infliximab in CD appear to be also mediated by inhibition of vascular inflammation in the gut.
Collapse
Affiliation(s)
- Silvio Danese
- Department of Internal Medicine, Catholic University, Rome, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Andrade RM, Wessendarp M, Portillo JAC, Yang JQ, Gomez FJ, Durbin JE, Bishop GA, Subauste CS. TNF receptor-associated factor 6-dependent CD40 signaling primes macrophages to acquire antimicrobial activity in response to TNF-alpha. THE JOURNAL OF IMMUNOLOGY 2005; 175:6014-21. [PMID: 16237096 DOI: 10.4049/jimmunol.175.9.6014] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IFN-gamma is considered an essential stimulus that allows macrophages to acquire activity against intracellular pathogens in response to a second signal such as TNF-alpha. However, protection against important pathogens can take place in the absence of IFN-gamma through mechanisms that are still dependent on TNF-alpha. Engagement of CD40 modulates antimicrobial activity in macrophages. However, it is not known whether CD40 can replace IFN-gamma as priming signal for induction of this response. We show that CD40 primes mouse macrophages to acquire antimicrobial activity in response to TNF-alpha. The effect of CD40 was not caused by modulation of IL-10 and TGF-beta production or TNFR expression and did not require IFN-alphabeta signaling. Induction of antimicrobial activity required cooperation between TNFR-associated factor 6-dependent CD40 signaling and TNFR2. These results support a paradigm where TNFR-associated factor 6 signaling downstream of CD40 alters the pattern of response of macrophages to TNF-alpha leading to induction of antimicrobial activity.
Collapse
Affiliation(s)
- Rosa M Andrade
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Andrade RM, Portillo JAC, Wessendarp M, Subauste CS. CD40 signaling in macrophages induces activity against an intracellular pathogen independently of gamma interferon and reactive nitrogen intermediates. Infect Immun 2005; 73:3115-23. [PMID: 15845519 PMCID: PMC1087328 DOI: 10.1128/iai.73.5.3115-3123.2005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Gamma interferon (IFN-gamma) is the major inducer of classical activation of macrophages. Classically activated mouse macrophages acquire antimicrobial activity that is largely dependent on the production of reactive nitrogen intermediates. However, protection against important intracellular pathogens can take place in the absence of IFN-gamma and nitric oxide synthase 2 (NOS2). Using Toxoplasma gondii as a model, we investigated if CD40 signaling generates mouse macrophages with effector function against an intracellular pathogen despite the absence of priming with IFN-gamma and lack of production of reactive nitrogen intermediates. CD40-stimulated macrophages acquired anti-T. gondii activity that was not inhibited by a neutralizing anti-IFN-gamma monoclonal antibody but was ablated by the neutralization of tumor necrosis factor alpha (TNF-alpha). Moreover, while the induction of anti-T. gondii activity in response to CD40 stimulation was unimpaired in macrophages from IFN-gamma(-/-) mice, macrophages from TNF receptor 1/2(-/-) mice failed to respond to CD40 engagement. In contrast to IFN-gamma-lipopolysaccharide, CD40 stimulation did not induce NOS2 expression and did not trigger production of reactive nitrogen intermediates. Neither N(G)-monomethyl-l-arginine nor diphenyleneiodonium chloride affected the induction of anti-T. gondii activity in response to CD40. Finally, macrophages from NOS2(-/-) mice acquired anti-T. gondii activity in response to CD40 stimulation that was similar to that of macrophages from wild-type mice. These results demonstrate that CD40 induces the antimicrobial activity of macrophages against an intracellular pathogen despite the lack of two central features of classically activated macrophages: priming with IFN-gamma and production of reactive nitrogen intermediates.
Collapse
Affiliation(s)
- Rosa M Andrade
- Department of Internal Medicine, University of Cincinnati College of Medicine, P.O. Box 670560, Cincinnati, OH 45267-0560, USA
| | | | | | | |
Collapse
|
27
|
Ghoneum M, Matsuura M. Augmentation of macrophage phagocytosis by modified arabinoxylan rice bran (MGN-3/biobran). Int J Immunopathol Pharmacol 2005; 17:283-92. [PMID: 15461862 DOI: 10.1177/039463200401700308] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
MGN-3/Biobran, modified arabinoxylan rice bran, has been shown to be a potent biological response modifier (BRM) as manifested by stimulation of different arms of the immune system such as NK, T and B cells; however, its effect on macrophages has not yet been studied. The effects of MGN-3 on macrophage function was examined in vitro using 3 models: human macrophage cell line U937, murine macrophage cell line RAW264.7, and murine peritoneal macrophages (P-M phi). Treatment with MGN-3 resulted in an increase in the percentages of attachment and phagocytosis of yeast by macrophages. The effect depends on the type of macrophage and the dose of MGN-3 applied. Macrophages also demonstrated enhancement in their spreading ability, post treatment with MGN-3. Results also showed that MGN-3, in a dose dependent manner (1, 10,100 microg/ml), significantly induced high levels of production of cytokines: TNF-alpha; and IL-6. In addition, MGN-3 significantly increased nitric oxide (NO) production. This data demonstrates that MGN-3 is a potent inducer of phagocytic function by macrophage, and suggests that MGN-3 is a useful agent for fighting microbial infection.
Collapse
Affiliation(s)
- M Ghoneum
- Department of Otolaryngology, Drew University of Medicine and Science, Los Angeles, CA 90059, USA
| | | |
Collapse
|