scholarly journals Early Induction of Interleukin-10 Limits Antigen-Specific CD4+T Cell Expansion, Function, and Secondary Recall Responses during Persistent Phagosomal Infection

2014 ◽  
Vol 82 (10) ◽  
pp. 4092-4103 ◽  
Author(s):  
Abinav Kumar Singh ◽  
Nagaraja R. Thirumalapura

ABSTRACTDiverse pathogens have evolved to survive and replicate in the endosomes or phagosomes of the host cells and establish persistent infection. Ehrlichiae are Gram-negative, intracellular bacteria that are transmitted by ticks. Ehrlichiae reside in the endosomes of the host phagocytic or endothelial cells and establish persistent infection in their vertebrate reservoir hosts. CD4+T cells play a critical role in protection against phagosomal infections. In the present study, we investigated the expansion, maintenance, and functional status of antigen-specific CD4+T cells during persistentEhrlichia murisinfection in wild-type and interleukin-10 (IL-10)-deficient mice. Our study indicated that early induction of IL-10 led to reduced inflammatory responses and impaired bacterial clearance during persistentEhrlichiainfection. Notably, we demonstrated that the functional production of gamma interferon (IFN-γ) by antigen-specific CD4+T cells maintained during a persistent phagosomal infection progressively deteriorates. The functional loss of IFN-γ production by antigen-specific CD4+T cells was reversed in the absence of IL-10. Furthermore, we demonstrated that transient blockade of IL-10 receptor during the T cell priming phase early in infection was sufficient to enhance the magnitude and the functional capacity of antigen-specific effector and memory CD4+T cells, which translated into an enhanced recall response. Our findings provide new insights into the functional status of antigen-specific CD4+T cells maintained during persistent phagosomal infection. The study supports the concept that a better understanding of the factors that influence the priming and differentiation of CD4+T cells may provide a basis to induce a protective immune response against persistent infections.

Blood ◽  
2012 ◽  
Vol 119 (1) ◽  
pp. 127-136 ◽  
Author(s):  
Min Chen ◽  
Kumar Felix ◽  
Jin Wang

AbstractAfter stimulation of antigen-specific T cells, dendritic cell (DCs) are susceptible to killing by these activated T cells that involve perforin and Fas-dependent mechanisms. Fas-dependent DC apoptosis has been shown to limit DC accumulation and prevent the development of autoimmunity. However, a role for perforin in the maintenance of DC homeostasis for immune regulation remains to be determined. Here we show that perforin deficiency in mice, together with the deletion of Fas in DCs (perforin−/−DC-Fas−/−), led to DC accumulation, uncontrolled T-cell activation, and IFN-γ production by CD8+ T cells, resulting in the development of lethal hemophagocytic lymphohistiocytosis. Consistently, adoptive transfer of Fas−/− DCs induced over-activation and IFN-γ production in perforin−/− CD8+ T cells. Neutralization of IFN-γ prevented the spreading of inflammatory responses to different cell types and protected the survival of perforin−/−DC-Fas−/− mice. Our data suggest that perforin and Fas synergize in the maintenance of DC homeostasis to limit T cell activation, and prevent the initiation of an inflammatory cascade.


2013 ◽  
Vol 82 (2) ◽  
pp. 903-913 ◽  
Author(s):  
Chiung-Yu Hung ◽  
Natalia Castro-Lopez ◽  
Garry T. Cole

ABSTRACTHigh concentrations of lung tissue-associated interleukin-10 (IL-10), an anti-inflammatory and immunosuppressive cytokine, correlate with susceptibility of mice toCoccidioidesspp. infection. In this study, we found that macrophages, dendritic cells, neutrophils, and both CD8+and CD4+T cells recruited toCoccidioides posadasii-infected lungs of nonvaccinated and vaccinated mice contributed to the production of IL-10. The major IL-10-producing leukocytes were CD8+T cells, neutrophils, and macrophages in lungs of nonvaccinated mice, while both Foxp3+and Foxp3−subsets of IL-10+CD4+T cells were significantly elevated in vaccinated mice. Profiles of the recruited leukocytes in lungs revealed that only CD4+T cells were significantly increased inIL-10−/−knockout mice compared to their wild-type counterparts. Furthermore,ex vivorecall assays showed that CD4+T cells isolated from vaccinatedIL-10−/−mice compared to vaccinated wild-type mice produced significantly higher amounts of IL-2, gamma interferon (IFN-γ), IL-4, IL-6, and IL-17A in the presence of a coccidioidal antigen, indicating that IL-10 suppresses Th1, Th2, and Th17 immunity toCoccidioidesinfection. Analysis of absolute numbers of CD44+CD62L−CD4+T effector memory T cells (TEM) and IFN-γ- and IL-17A-producing CD4+T cells in the lungs ofCoccidioides-infected mice correlated with better fungal clearance in nonvaccinatedIL-10−/−mice than in nonvaccinated wild-type mice. Our results suggest that IL-10 suppresses CD4+T-cell immunity in nonvaccinated mice duringCoccidioidesinfection but does not impede the development of a memory response nor exacerbate immunopathology of vaccinated mice over at least a 4-month period after the last immunization.


2007 ◽  
Vol 76 (3) ◽  
pp. 1179-1185 ◽  
Author(s):  
Stacie Reckling ◽  
Senad Divanovic ◽  
Christopher L. Karp ◽  
Sara Wojciechowski ◽  
Yasmine Belkaid ◽  
...  

ABSTRACT Following the peak of the T-cell response, most of the activated effector T cells die by apoptosis driven by the proapoptotic Bcl-2 family member Bim (Bcl-2-interacting mediator of death). Whether the absence of Bim-mediated T-cell apoptosis can affect protective immunity remains unclear. Here, we used a mouse model of Leishmania major infection, in which parasite persistence and protective immunity are controlled by an equilibrium reached between parasite-specific gamma interferon (IFN-γ)-producing effector T cells and interleukin-10 (IL-10)-producing CD4+ CD25+ T regulatory cells. To further understand the role of Bim-mediated apoptosis in persistent infection and protective immunity, we infected Bim −/− mice with L. major. We found that the initial parasite growth and lesion development were similar in Bim −/− and wild-type mice after primary L. major infection. However, at later times after infection, Bim −/− mice had significantly increased L. major-specific CD4+ T-cell responses and were resistant to persistent infection. Interestingly, despite their resistance to primary L. major infection, Bim −/− mice displayed significantly enhanced protection against challenge with L. major. Increased resistance to challenge in Bim −/− mice was associated with a significant increase in the number of L. major-specific IFN-γ-producing CD4+ T cells and a lack of IL-10 production at the challenge site. Taken together, these data suggest that Bim limits protective immunity and that the absence of Bim allows the host to bypass antigen persistence for maintenance of immunity against reinfection.


2019 ◽  
Vol 87 (6) ◽  
Author(s):  
Hui Lin ◽  
Conghui He ◽  
John J. Koprivsek ◽  
Jianlin Chen ◽  
Zhiguang Zhou ◽  
...  

ABSTRACTThe genital tract pathogenChlamydia trachomatisis frequently detected in the gastrointestinal tract, but the host immunity that regulates chlamydial colonization in the gut remains unclear. In aChlamydia muridarum-C57 mouse model, chlamydial organisms are cleared from the genital tract in ∼4 weeks, but the genital organisms can spread to the gastrointestinal tract. We found that the gastrointestinal chlamydial organisms were cleared from the small intestine by day 28, paralleling their infection course in the genital tract, but persisted in the large intestine for long periods. Mice deficient in α/β T cells or CD4+T cells but not CD8+T cells showed chlamydial persistence in the small intestine, indicating a critical role for CD4+T cells in clearingChlamydiafrom the small intestine. The CD4+T cell-dependent clearance is likely mediated by gamma interferon (IFN-γ), since mice deficient in IFN-γ but not interleukin 22 (IL-22) signaling pathways rescued chlamydial colonization in the small intestine. Furthermore, exogenous IFN-γ was sufficient for clearingChlamydiafrom the small intestine but not the large intestine. Mice deficient in developingChlamydia-specific Th1 immunity showed chlamydial persistence in the small intestine. Finally, IFN-γ-producing CD4+but not CD8+T cells from immunized donor mice were sufficient for eliminatingChlamydiafrom the small intestine but not the large intestine of recipient mice. Thus, we have demonstrated a critical role for Th1 immunity in clearingChlamydiafrom the small intestine but not the large intestine, indicating that chlamydial colonization in different regions of the gastrointestinal tract is regulated by distinct immune mechanisms.


2017 ◽  
Vol 85 (6) ◽  
Author(s):  
Carla Claser ◽  
J. Brian De Souza ◽  
Samuel G. Thorburn ◽  
Georges Emile Grau ◽  
Eleanor M. Riley ◽  
...  

ABSTRACT The resolution of malaria infection is dependent on a balance between proinflammatory and regulatory immune responses. While early effector T cell responses are required for limiting parasitemia, these responses need to be switched off by regulatory mechanisms in a timely manner to avoid immune-mediated tissue damage. Interleukin-10 receptor (IL-10R) signaling is considered to be a vital component of regulatory responses, although its role in host resistance to severe immune pathology during acute malaria infections is not fully understood. In this study, we have determined the contribution of IL-10R signaling to the regulation of immune responses during Plasmodium berghei ANKA-induced experimental cerebral malaria (ECM). We show that antibody-mediated blockade of the IL-10R during P. berghei ANKA infection in ECM-resistant BALB/c mice leads to amplified T cell activation, higher serum gamma interferon (IFN-γ) concentrations, enhanced intravascular accumulation of both parasitized red blood cells and CD8+ T cells to the brain, and an increased incidence of ECM. Importantly, the pathogenic effects of IL-10R blockade during P. berghei ANKA infection were reversible by depletion of T cells and neutralization of IFN-γ. Our findings underscore the importance of IL-10R signaling in preventing T-cell- and cytokine-mediated pathology during potentially lethal malaria infections.


2017 ◽  
Vol 85 (8) ◽  
Author(s):  
Lucia Trotta ◽  
Kathleen Weigt ◽  
Katina Schinnerling ◽  
Anika Geelhaar-Karsch ◽  
Gerrit Oelkers ◽  
...  

ABSTRACT Classical Whipple's disease (CWD) is characterized by the lack of specific Th1 response toward Tropheryma whipplei in genetically predisposed individuals. The cofactor GrpE of heat shock protein 70 (Hsp70) from T. whipplei was previously identified as a B-cell antigen. We tested the capacity of Hsp70 and GrpE to elicit specific proinflammatory T-cell responses. Peripheral mononuclear cells from CWD patients and healthy donors were stimulated with T. whipplei lysate or recombinant GrpE or Hsp70 before levels of CD40L, CD69, perforin, granzyme B, CD107a, and gamma interferon (IFN-γ) were determined in T cells by flow cytometry. Upon stimulation with total bacterial lysate or recombinant GrpE or Hsp70 of T. whipplei, the proportions of activated effector CD4+ T cells, determined as CD40L+ IFN-γ+, were significantly lower in patients with CWD than in healthy controls; CD8+ T cells of untreated CWD patients revealed an enhanced activation toward unspecific stimulation and T. whipplei-specific degranulation, although CD69+ IFN-γ+ CD8+ T cells were reduced upon stimulation with T. whipplei lysate and recombinant T. whipplei-derived proteins. Hsp70 and its cofactor GrpE are immunogenic in healthy individuals, eliciting effective responses against T. whipplei to control bacterial spreading. The lack of specific T-cell responses against these T. whipplei-derived proteins may contribute to the pathogenesis of CWD.


2020 ◽  
Vol 88 (11) ◽  
Author(s):  
Emily M. Siebers ◽  
Elizabeth S. Liedhegner ◽  
Michael W. Lawlor ◽  
Ronald F. Schell ◽  
Dean T. Nardelli

ABSTRACT The symptoms of Lyme disease are caused by inflammation induced by species of the Borrelia burgdorferi sensu lato complex. The various presentations of Lyme disease in the population suggest that differences exist in the intensity and regulation of the host response to the spirochete. Previous work has described correlations between the presence of regulatory T cells and recovery from Lyme arthritis. However, the effects of Foxp3-expressing CD4+ T cells existing prior to, and during, B. burgdorferi infection have not been well characterized. Here, we used C57BL/6 “depletion of regulatory T cell” mice to assess the effects these cells have on the arthritis-resistant phenotype characteristic of this mouse strain. We showed that depletion of regulatory T cells prior to infection with B. burgdorferi resulted in sustained swelling, as well as histopathological changes, of the tibiotarsal joints that were not observed in infected control mice. Additionally, in vitro stimulation of splenocytes from these regulatory T cell-depleted mice resulted in increases in gamma interferon and interleukin-17 production and decreases in interleukin-10 production that were not evident among splenocytes of infected mice in which Treg cells were not depleted. Depletion of regulatory T cells at various times after infection also induced rapid joint swelling. Collectively, these findings provide evidence that regulatory T cells existing at the time of, and possibly after, B. burgdorferi infection may play an important role in limiting the development of arthritis.


2001 ◽  
Vol 69 (10) ◽  
pp. 6064-6073 ◽  
Author(s):  
Cinzia Retini ◽  
Thomas R. Kozel ◽  
Donatella Pietrella ◽  
Claudia Monari ◽  
Francesco Bistoni ◽  
...  

ABSTRACT We previously demonstrated that the principal component of capsular material of Cryptococcus neoformans, glucuronoxylomannan (GXM), induces interleukin-10 (IL-10) secretion from human monocytes. Here we report that encapsulation of the yeast with GXM is able to down-regulate interleukin-12 (IL-12) production by monocytes that would normally occur in the absence of encapsulation. This phenomenon appeared to be the result of inhibition of the phagocytic process by encapsulation with GXM as well as of negative signals such as IL-10 secretion produced by interaction of GXM with leukocytes. Decreased secretion of IL-12 correlated with decreased release of gamma interferon (IFN-γ) from T cells, suggesting a role for encapsulation with GXM in hindering a T helper type 1 (Th1) response. This is supported by the ability of encapsulation with GXM to limit increased expression of B7-1 costimulatory molecules that otherwise might limit IL-10 secretion. Endogenous IL-10 played a critical role in modulatory activity associated with encapsulation with GXM. Blocking IL-10 with monoclonal antibody to IL-10 resulted in increased (i) IL-12 secretion, (ii) IFN-γ release from T cells, and (iii) killing of C. neoformans by monocytes. These results suggest that encapsulation with GXM limits development of a protective Th1-type response, an inhibitory process in which IL-10 plays a critical role. Scavengers of GXM and/or IL-10 could be useful in a protective Th1-type response in patients with cryptococcosis.


2017 ◽  
Vol 24 (11) ◽  
Author(s):  
Ahreum Kim ◽  
Yun-Gyoung Hur ◽  
Sunwha Gu ◽  
Sang-Nae Cho

ABSTRACT The aim of this study was to evaluate the protective efficacy of MTBK_24820, a complete form of PPE39 protein derived from a predominant Beijing/K strain of Mycobacterium tuberculosis in South Korea. Mice were immunized with MTKB_24820, M. bovis Bacilli Calmette-Guérin (BCG), or adjuvant prior to a high-dosed Beijing/K strain aerosol infection. After 4 and 9 weeks, bacterial loads were determined and histopathologic and immunologic features in the lungs and spleens of the M. tuberculosis-infected mice were analyzed. Putative immunogenic T-cell epitopes were examined using synthetic overlapping peptides. Successful immunization of MTBK_24820 in mice was confirmed by increased IgG responses (P < 0.05) and recalled gamma interferon (IFN-γ), interleukin-2 (IL-2), IL-6, and IL-17 responses (P < 0.05 or P < 0.01) to MTBK_24820. After challenge with the Beijing/K strain, an approximately 0.5 to 1.0 log10 reduction in CFU in lungs and fewer lung inflammation lesions were observed in MTBK_24820-immunized mice compared to those for control mice. Moreover, MTBK_24820 immunization elicited significantly higher numbers of CD4+ T cells producing protective cytokines, such as IFN-γ and IL-17, in lungs and spleens (P < 0.01) and CD4+ multifunctional T cells producing IFN-γ, tumor necrosis factor alpha (TNF-α), and/or IL-17 (P < 0.01) than in control mice, suggesting protection comparable to that of BCG against the hypervirulent Beijing/K strain. The dominant immunogenic T-cell epitopes that induced IFN-γ production were at the N terminus (amino acids 85 to 102 and 217 to 234). Its vaccine potential, along with protective immune responses in vivo, may be informative for vaccine development, particularly in regions where the M. tuberculosis Beijing/K-strain is frequently isolated from TB patients.


Blood ◽  
1997 ◽  
Vol 90 (11) ◽  
pp. 4513-4521 ◽  
Author(s):  
Dieter Körholz ◽  
Ursula Banning ◽  
Halvard Bönig ◽  
Markus Grewe ◽  
Marion Schneider ◽  
...  

Abstract Interleukin-15 (IL-15) is a potent T-cell stimulating factor, which has recently been used for pre-clinical in vivo immunotherapy. Here, the IL-15 effect on CD3-stimulated peripheral human T cells was investigated. IL-15 induced a significant T-cell proliferation and upregulated CD25 expression. IL-15 significantly enhanced T-cell production of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and IL-10. Between 10- and 100-fold greater concentrations of IL-15 were necessary to reach a biological effect equivalent to that of IL-2. Blockade of IL-2 binding to the high-affinity IL-2 receptor did not affect the IL-15 effects, suggesting that IL-15 did not act by inducing endogenous IL-2. Exogenously administered IL-10 significantly reduced the IL-15 and IL-2–mediated IFN-γ and TNF-α production, whereas T-cell proliferation and CD25 expression were not affected. The inhibitory effects of exogenously administered IL-10 on T-cell cytokine production appeared indirect, and are likely secondary to decreased IL-12 production by accessory cells. Inhibition of endogenous IL-10 binding to the IL-10 receptor significantly increased IFN-γ and TNF-α release from T cells. These data suggest that endogenous IL-10 can regulate activated T-cell production of IFN-γ and TNF-α via a paracrine negative feedback loop. The observations of this study could be of relevance for the therapeutic use of IL-15 in vivo.


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