scholarly journals Contribution of Interleukin-12 (IL-12) and the CD28/B7 and CD40/CD40 Ligand Pathways to the Development of a Pathological T-Cell Response in IL-10-Deficient Mice

2002 ◽  
Vol 70 (12) ◽  
pp. 6940-6947 ◽  
Author(s):  
Ulrike Wille ◽  
Eric N. Villegas ◽  
Linden Craig ◽  
Robert Peach ◽  
Christopher A. Hunter

ABSTRACT The ability of interleukin-10 (IL-10) to suppress accessory cell functions required for optimal T-cell activation makes it an important inhibitor of cell-mediated immunity. Thus, after infection with the protozoan parasite Toxoplasma gondii, IL-10 knockout (KO) mice develop a CD4+-T-cell-dependent shock-like reaction with high levels of IL-12 and gamma interferon (IFN-γ) in serum, leading to death of mice during the acute phase of infection. Previous studies from this laboratory have shown that simultaneous blockade of CD28 and CD40 can prevent this lethal reaction by inhibiting the production of IFN-γ. However, the blockade of costimulation did not affect systemic levels of IL-12. To better understand the relationship between IL-12 and the CD28 and CD40 pathways in mediating immune hyperactivity, antagonists of these factors were used to determine their effects on the development of a pathological T-cell response in IL-10 KO mice. Blockade of IL-12 or the CD28/B7 interaction alone did not affect survival; however, the combined blockade of both pathways resulted in decreased production of IFN-γ and the survival of IL-10 KO mice. To assess the role of the two ligands for CD28, B7.1 and B7.2, IL-10 KO mice were treated with αIL-12 plus αB7.1 or αB7.2 or the combination of all three antibodies. These studies revealed that blockade of both B7 molecules is required for decreased production of IFN-γ and survival of infected IL-10 KO mice, suggesting that B7.1 and B7.2 can contribute to the lethal shock-like reaction in IL-10 KO mice. In contrast, neutralization of IL-12 and blockade of the CD40/CD40 ligand (CD40L) interaction in vivo did not alter the production of IFN-γ and only resulted in a small delay in time to death of mice. Together, these data suggest that the CD28/B7 interaction has a central role in the development of a pathological T-cell response in IL-10 KO mice, which is distinct from the role of the CD40/CD40L and IL-12 pathways.

2000 ◽  
Vol 68 (5) ◽  
pp. 2837-2844 ◽  
Author(s):  
Eric N. Villegas ◽  
Ulrike Wille ◽  
Linden Craig ◽  
Peter S. Linsley ◽  
Donna M. Rennick ◽  
...  

ABSTRACT Interleukin-10 (IL-10) is associated with inhibition of cell-mediated immunity and downregulation of the expression of costimulatory molecules required for T-cell activation. When IL-10-deficient (IL-10KO) mice are infected with Toxoplasma gondii, they succumb to a T-cell-mediated shock-like reaction characterized by the overproduction of IL-12 and gamma interferon (IFN-γ) associated with widespread necrosis of the liver. Since costimulation is critical for T-cell activation, we investigated the role of the CD28-B7 and CD40-CD40 ligand (CD40L) interactions in this infection-induced immunopathology. Our studies show that infection of mice with T. gondii resulted in increased expression of B7 and CD40 that was similar in wild-type and IL-10KO mice. In vivo blockade of the CD28-B7 or CD40-CD40L interactions following infection of IL-10KO mice with T. gondii did not affect serum levels of IFN-γ or IL-12, nor did it prevent death in these mice. However, when both pathways were blocked, the IL-10KO mice survived the acute phase of infection and had reduced serum levels of IFN-γ and alanine transaminase as well as decreased expression of inducible nitric oxide synthase in the liver and spleen. Analysis of parasite-specific recall responses from infected IL-10KO mice revealed that blockade of the CD40-CD40L interaction had minimal effects on cytokine production, whereas blockade of the CD28-B7 interaction resulted in decreased production of IFN-γ but not IL-12. Further reduction of IFN-γ production was observed when both costimulatory pathways were blocked. Together, these results demonstrate that the CD28-B7 and CD40-CD40L interactions are involved in the development of infection-induced immunopathology in the absence of IL-10.


2007 ◽  
Vol 81 (10) ◽  
pp. 4928-4940 ◽  
Author(s):  
Maya F. Kotturi ◽  
Bjoern Peters ◽  
Fernando Buendia-Laysa ◽  
John Sidney ◽  
Carla Oseroff ◽  
...  

ABSTRACT CD8+ T-cell responses control lymphocytic choriomeningitis virus (LCMV) infection in H-2b mice. Although antigen-specific responses against LCMV infection are well studied, we found that a significant fraction of the CD8+ CD44hi T-cell response to LCMV in H-2b mice was not accounted for by known epitopes. We screened peptides predicted to bind major histocompatibility complex class I and overlapping 15-mer peptides spanning the complete LCMV proteome for gamma interferon (IFN-γ) induction from CD8+ T cells derived from LCMV-infected H-2b mice. We identified 19 novel epitopes. Together with the 9 previously known, these epitopes account for the total CD8+ CD44hi response. Thus, bystander T-cell activation does not contribute appreciably to the CD8+ CD44hi pool. Strikingly, 15 of the 19 new epitopes were derived from the viral L polymerase, which, until now, was not recognized as a target of the cellular response induced by LCMV infection. The L epitopes induced significant levels of in vivo cytotoxicity and conferred protection against LCMV challenge. Interestingly, protection from viral challenge was best correlated with the cytolytic potential of CD8+ T cells, whereas IFN-γ production and peptide avidity appear to play a lesser role. Taken together, these findings illustrate that the LCMV-specific CD8+ T-cell response is more complex than previously appreciated.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2668-2668
Author(s):  
Abdul Tawab ◽  
Yoshiyuki Takahashi ◽  
Childs Richard ◽  
Kurlander J. Roger

Abstract In vitro stimulation of human peripheral blood B cells with recombinant IL-4 and CD40 ligand (CD40L) markedly increases their expression of MHC and costimulatory molecules, thus enhancing antigenic peptide presentation to T cells. Because these cells proliferate extensively in vitro (unlike monocytes or dendritic cells), they represent a promising and convenient reagent for the generation and maintenance of antigen-specific T cells for use in a variety of experimental or therapeutic settings. However, the impact of this type of B cell APC on cytokine production by responder T cells has hitherto not been examined. To address this issue, we stimulated normal human T cells with either allogeneic B cells (generated in vitro) or with MNCs obtained from the same donor. After 7 days, T cells were washed and re-challenged with the same APCs. The resulting alloreactive cytokine response was measured using quantitative ELISPOT methods and expressed as the frequencies of IFN-γ, IL-4, and IL-5 producing cells per thousand responder cells added. B cell- and MNC-primed cell lines both produced vigorous lymphokine responses, but B cell-stimulated T cells consistently produced more IL-5 spots (mean of 265 vs. 98/1000 responders, p<0.002) and fewer IFN-γ spots (163 vs 386/1000 cells, p<0.005) than MNC-stimulated cells. Further, the ratio of IFN-γ to IL-5 spots was almost ten-fold lower in B cell-stimulated cultures compared to MNC-induced cultures (0.67 vs. 5.2, p<0.001). ELISPOT studies assessing the ratio of IFN-γ to IL-4 spots and ELISA assays comparing IFN-γ and IL-5 levels from culture supernatants demonstrated the same pattern of marked type 2 skewing by B cells. This pattern was unaffected by the presence of anti-IL-4 antibody suggesting type 2 skewing was not mediated by IL-4. Cytokine skewing produced by B cells or MNC could be partially reversed by swapping MNC and B cells during re-stimulation on day 7, but this plasticity was markedly reduced after 3 (weekly) cycles of B cell or MNC re-stimulation in vitro. Type 2 skewing by B cells was enhanced when monocytes were removed from responder T cell populations by either depleting CD14+ positive cells or by positive selection of T cells prior to stimulation. In contrast, type 2 polarization could be prevented using recombinant IL-12. Not all cells of B-cell origin share the same propensity to type 2 skewing observed with IL-4/CD40L-stimulated B cells; under identical conditions, EBV-transformed B cells stimulated alloimmune T cells to produce a strong type 1 cytokine response comparable to that produced by MNCs. In summary, IL-4/CD40L-stimulated B cells strongly promote a type 2 T cell response during primary alloimmune challenge; this skewing can become fixed after repeated B cell stimulation. Investigators using these cells as APC should be aware of this potential phenomenon, particularly during primary T cell responses. It is also important to consider the factors described above that may exacerbate or ameliorate this effect.


2000 ◽  
Vol 68 (3) ◽  
pp. 1312-1318 ◽  
Author(s):  
Gaby Reichmann ◽  
William Walker ◽  
Eric N. Villegas ◽  
Linden Craig ◽  
Guifang Cai ◽  
...  

ABSTRACT Since the CD40/CD40 ligand (CD40L) interaction is involved in the regulation of macrophage production of interleukin 12 (IL-12) and T-cell production of gamma interferon (IFN-γ), effector cell functions associated with resistance to Toxoplasma gondii, the role of CD40L in immunity to this parasite was assessed. Infection of C57BL/6 mice with T. gondii results in an upregulation of CD40 expression on accessory cell populations at local sites of infection as well as in lymphoid tissues. Splenocytes from C57BL/6 mice infected with T. gondii for 5 days produced high levels of IL-12 and IFN-γ when stimulated with toxoplasma lysate antigen, and blocking CD40L did not significantly alter the production of IFN-γ or IL-12 by these cells. Similar results were observed with splenocytes and mononuclear cells isolated from the brains of chronically infected mice. Interestingly, although CD40L−/− mice infected withT. gondii produced less IL-12 than wild-type mice, they produced comparable levels of IFN-γ but succumbed to toxoplasmic encephalitis 4 to 5 weeks after infection. The inability of CD40L−/− mice to control parasite replication in the brain correlated with the ability of soluble CD40L, in combination with IFN-γ, to activate macrophages in vitro to control replication ofT. gondii. Together, these results identify an important role for the CD40/CD40L interaction in resistance to T. gondii. However, this interaction may be more important in the control of parasite replication in the brain rather than the generation of protective T-cell responses during toxoplasmosis.


2013 ◽  
Vol 93 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Dalia E. Gaddis ◽  
Craig L. Maynard ◽  
Casey T. Weaver ◽  
Suzanne M. Michalek ◽  
Jannet Katz
Keyword(s):  
T Cell ◽  

1999 ◽  
Vol 67 (11) ◽  
pp. 5747-5754 ◽  
Author(s):  
Irene S. Leal ◽  
Birgitte Smedegård ◽  
Peter Andersen ◽  
Rui Appelberg

ABSTRACT We examined the role of cytokines in the development of gamma interferon (IFN-γ)-secreting protective T cells following immunization with a culture filtrate subunit vaccine againstMycobacterium tuberculosis containing the adjuvant dimethyldioctadecylammonium bromide (DDA). Depletion of either interleukin-6 (IL-6) or IL-12 with specific neutralizing antibodies during vaccination reduced the priming of T cells for antigen-specific proliferation and IFN-γ secretion. Such reduction was also observed in IL-6 gene-disrupted mice as compared to wild-type animals. IL-6 was found to play a role in the initial differentiation of Th1 cells but not in their expansion. The defect found after IL-6 depletion or in IL-6-knockout mice was compensated by the inclusion of recombinant mouse IL-12 in the vaccine. The induction of protective immunity against an intravenous or an aerosol challenge with live, virulentM. tuberculosis was markedly reduced by neutralizing either IL-6 or IL-12 during immunization with the vaccine. Likewise, the effects of IL-6 neutralization were partially reversed by including IL-12 in the vaccine. Our data point to an important role of IL-6 and IL-12 in the generation of cell-mediated immunity to tuberculosis.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 100-100
Author(s):  
Ryan Jajosky ◽  
Connie Arthur ◽  
Jerry Allen ◽  
Megan Fuller ◽  
Patricia E Zerra ◽  
...  

Background: Exposure to red blood cell (RBC) alloantigens during pregnancy or transfusion can lead to the development of alloantibodies and result in transfusion-related complications, including hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. However, the factors that regulate RBC alloimmunization remain incompletely understood. Several studies suggest that alterations in factors that regulate RBC clearance may impact RBC uptake and antigen presentation, directly influencing the likelihood of RBC alloimmunization. To test this, we directly examined the potential role of CD47, a master regulator of RBC removal previously shown to be altered during RBC senescence and cold storage. To accomplish this, we crossed transgenic mice that express the model HOD antigen (a fusion protein consisting of hen egg lysozyme fused to ovalbumin and human Duffy b) with CD47 knock out (KO) mice to generate HOD RBC donors with wild type, heterozygous or homozygous KO levels of CD47 and used these donors to define the impact of CD47 on antibody formation following RBC transfusion. Methods: HOD transgenic mice expressing the HOD antigen exclusively on RBCs were crossed with CD47-/- mice to produce HOD CD47+/- or HOD CD47-/- mice. HOD and CD47 levels were assessed by flow cytometric analysis using anti-HOD and anti-CD47 antibodies. HOD CD47+/+, HOD CD47+/- or HOD CD47-/- RBCs were transfused into C57BL6 recipients, followed by serum collection on days 14 and 28 post transfusion and evaluation of anti-HOD antibodies by flow cytometry crossmatch. To determine the CD4 T cell response to transfusion, TCR transgenics specific to ovalbumin (OTII) were labeled with CFSE, followed by adoptive transfer, transfusion of HOD CD47+/+, HOD CD47+/- or HOD CD47-/- RBCs and evaluation of T cell proliferation, activation and cytokine secretion. Cellular removal of HOD RBCs was determined by flow cytometric examination of CFSE-labeled HOD RBCs. Finally, antigen levels on HOD RBCs was determined by staining cells with anti-HEL antibodies followed by flow cytometric examination. All three groups were subjected to one-way ANOVA analysis with a p value &lt;0.05 considered significant. Results: While HOD CD47+/+ RBCs expressed levels of CD47 comparable to WT RBCs, HOD CD47+/- RBCs exhibited significantly reduced CD47 levels (nearly half that observed on WT HOD RBCs) and HOD CD47-/-RBCs failed to express any detectable CD47 (p &lt; 0.0001). Following transfusion, HOD CD47+/- and HOD CD47-/- RBCs produced significantly higher levels of IgG anti-HOD antibodies than HOD CD47+/+ RBCs on days 14 and 28 post-transfusion (p &lt; 0.001). However, while HOD CD47-/- RBCs displayed increased clearance consistent with the possible enhancement of a CD4 T cell response (p &lt; 0.0001), HOD CD47+/- RBCs failed to exhibit any different in clearance when compared to HOD CD47+/+ RBCs overtime. To examine the potential impact of differences in HOD RBC clearance on CD4 T cell activation, OTII T cell proliferation was evaluated. While HOD CD47-/- RBC transfusion resulted in significantly increased 33D1+ dendritic cell uptake, OTII proliferation, activation and cytokine secretion (p &lt; 0.05), no difference in 33D1+ dendritic cell uptake or T cell response was observed following HOD CD47+/+ RBC or HOD CD47+/- RBC transfusion. Instead, HOD CD47+/- RBCs exhibited enhanced antigen removal, while also displaying an increased ability to activate HEL specific B cells when compared to HOD CD47+/+ or HOD CD47-/- RBC transfusion. Conclusions: These results demonstrate that alterations in CD47, which occur during normal RBC senescence and cold storage, directly influence RBC alloimmunization through different mechanisms depending on the extent of CD47 loss. While complete loss of CD47 results in enhanced RBC clearance, antigen presentation and CD4 T cell activation, reductions in CD47 to half WT levels failed to impact RBC clearance or T cell activation, but instead enhanced antigen specific B cell activation. These results demonstrate that even partial loss of CD47 is capable of significantly enhancing alloantibody formation completely independent of its role in regulating RBC clearance. In doing so, these findings provide novel insight into the role of CD47 as a key regulator of RBC alloimmunization. Disclosures Stowell: Grifols: Honoraria.


1997 ◽  
Vol 185 (7) ◽  
pp. 1327-1336 ◽  
Author(s):  
Yan Wu ◽  
Yong Guo ◽  
Andy Huang ◽  
Pan Zheng ◽  
Yang Liu

T cell costimulation, particularly by the B7 family members B7-1 and B7-2, plays a critical role in regulating T cell–mediated immunity. Two molecules on T cells, CD28 and CTLA-4, are known to bind to B7. It has been suggested that CD28–B7 interaction promotes T cell response, whereas B7–CTLA-4 interaction downregulates T cell clonal expansion. However, the proposed responses of individual receptors to B7 have not been verified directly. Here, we report that B7-1 promotes clonal expansion of CD28-deficient T cells, and that the CD28-independent costimulatory activity is mediated by CTLA-4, as it is completely blocked by intact and Fab of anti–CTLA-4 mAb. In addition, a mutant B7-1 molecule, B7W88 &gt;A, which has lost binding to CD28 but retained significant CTLA-4 binding activity, promotes T cell clonal expansion. Furthermore, while presence of CD28 enhances T cell response to B7-1, such response is also completely blocked by anti–CTLA-4 mAb. Taken together, our results demonstrate that B7–CTLA-4 interaction promotes T cell clonal expansion, and that optimal T cell response to B7 is achieved when both CD28 and CTLA-4 interact with B7. These results establish an important function of CTLA-4 in promoting T cell activation, and suggest an alternative interpretation of the function of CTLA-4 in T cell activation.


2002 ◽  
Vol 195 (11) ◽  
pp. 1463-1470 ◽  
Author(s):  
Imtiaz A. Khan ◽  
Magali Moretto ◽  
Xiao-qing Wei ◽  
Martha Williams ◽  
Joseph D. Schwartzman ◽  
...  

Interferon (IFN)-γ–producing CD8+ T cells are important for the successful resolution of the obligate intracellular parasite Toxoplasma gondii by preventing the reactivation or controlling a repeat infection. Previous reports from our laboratory have shown that exogenous interleukin (IL)-15 treatment augments the CD8+ T cell response against the parasite. However, the role of endogenous IL-15 in the proliferation of activated/memory CD8+ T cells during toxoplasma or any other infection is unknown. In this study, we treated T. gondii immune mice with soluble IL-15 receptor α (sIL-15Rα) to block the host endogenous IL-15. The treatment markedly reduced the ability of the immune animals to control a lethal infection. CD8+ T cell activities in the sIL-15Rα–administered mice were severely reduced as determined by IFN-γ release and target cell lysis assays. The loss of CD8+ T cell immunity due to sIL-15Rα treatment was further demonstrated by adoptive transfer experiments. Naive recipients transferred with CD44hi activated/memory CD8+ T cells and treated with sIL-15Rα failed to resist a lethal T. gondii infection. Moreover, sIL-15Rα treatment of the recipients blocked the ability of donor CD44hi activated/memory CD8+ T cells to replicate in response to T. gondii challenge. To our knowledge, this is the first demonstration of the important role of host IL-15 in the development of antigen-specific memory CD8+ T cells against an intracellular infection.


Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1716
Author(s):  
Anwesha Kar ◽  
Shikhar Mehrotra ◽  
Shilpak Chatterjee

Activation and subsequent differentiation of T cells following antigenic stimulation are triggered by highly coordinated signaling events that lead to instilling cells with a discrete metabolic and transcriptional feature. Compelling studies indicate that intracellular nicotinamide adenine dinucleotide (NAD+) levels have profound influence on diverse signaling and metabolic pathways of T cells, and hence dictate their functional fate. CD38, a major mammalian NAD+ glycohydrolase (NADase), expresses on T cells following activation and appears to be an essential modulator of intracellular NAD+ levels. The enzymatic activity of CD38 in the process of generating the second messenger cADPR utilizes intracellular NAD+, and thus limits its availability to different NAD+ consuming enzymes (PARP, ART, and sirtuins) inside the cells. The present review discusses how the CD38-NAD+ axis affects T cell activation and differentiation through interfering with their signaling and metabolic processes. We also describe the pivotal role of the CD38-NAD+ axis in influencing the chromatin remodeling and rewiring T cell response. Overall, this review emphasizes the crucial contribution of the CD38−NAD+ axis in altering T cell response in various pathophysiological conditions.


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