scholarly journals The Early Kinetics of Cytomegalovirus-Specific CD8+ T-Cell Responses Are Not Affected by Antigen Load or the Absence of Perforin or Gamma Interferon

2008 ◽  
Vol 82 (10) ◽  
pp. 4931-4937 ◽  
Author(s):  
Daniel M. Andrews ◽  
Christopher E. Andoniou ◽  
Peter Fleming ◽  
Mark J. Smyth ◽  
Mariapia A. Degli-Esposti

ABSTRACT Both innate and adaptive immune responses participate in the control of murine cytomegalovirus (mCMV) infection. In some mouse strains, like BALB/c, the control of infection relies on the activities of CD8+ T cells. mCMV-specific CD8+ T-cell responses are unusual in that, even after mCMV has been controlled in the periphery, the numbers of circulating virus-specific CD8+ T cells remain high compared to those observed in other viral infections. To better understand the generation and maintenance of mCMV-specific CD8+ T-cell responses, we evaluated how antigen load and effector molecules, such as perforin (Prf) and gamma interferon (IFN-γ), influence these responses during acute infection in vivo. Viral burden affected the magnitude, but not the early kinetics, of antigen-specific CD8+ T-cell responses. Similarly, the magnitude of virus-specific CD8+ T-cell expansion was affected by Prf and IFN-γ, but contraction of antigen-specific responses occurred normally in both Prf- and IFN-γ-deficient mice. These data indicate that control of mCMV-specific CD8+ T-cell expansion and contraction is more complex than anticipated and, despite the role of Prf or IFN-γ in controlling viral replication, a full program of T-cell expansion and contraction can occur in their absence.

2021 ◽  
pp. annrheumdis-2021-220435
Author(s):  
Theresa Graalmann ◽  
Katharina Borst ◽  
Himanshu Manchanda ◽  
Lea Vaas ◽  
Matthias Bruhn ◽  
...  

ObjectivesThe monoclonal anti-CD20 antibody rituximab is frequently applied in the treatment of lymphoma as well as autoimmune diseases and confers efficient depletion of recirculating B cells. Correspondingly, B cell-depleted patients barely mount de novo antibody responses during infections or vaccinations. Therefore, efficient immune responses of B cell-depleted patients largely depend on protective T cell responses.MethodsCD8+ T cell expansion was studied in rituximab-treated rheumatoid arthritis (RA) patients and B cell-deficient mice on vaccination/infection with different vaccines/pathogens.ResultsRituximab-treated RA patients vaccinated with Influvac showed reduced expansion of influenza-specific CD8+ T cells when compared with healthy controls. Moreover, B cell-deficient JHT mice infected with mouse-adapted Influenza or modified vaccinia virus Ankara showed less vigorous expansion of virus-specific CD8+ T cells than wild type mice. Of note, JHT mice do not have an intrinsic impairment of CD8+ T cell expansion, since infection with vaccinia virus induced similar T cell expansion in JHT and wild type mice. Direct type I interferon receptor signalling of B cells was necessary to induce several chemokines in B cells and to support T cell help by enhancing the expression of MHC-I.ConclusionsDepending on the stimulus, B cells can modulate CD8+ T cell responses. Thus, B cell depletion causes a deficiency of de novo antibody responses and affects the efficacy of cellular response including cytotoxic T cells. The choice of the appropriate vaccine to vaccinate B cell-depleted patients has to be re-evaluated in order to efficiently induce protective CD8+ T cell responses.


2003 ◽  
Vol 77 (8) ◽  
pp. 4781-4793 ◽  
Author(s):  
Michelina Nascimbeni ◽  
Eishiro Mizukoshi ◽  
Markus Bosmann ◽  
Marian E. Major ◽  
Kathleen Mihalik ◽  
...  

ABSTRACT The immunological correlates of hepatitis C virus (HCV)-specific immunity are not well understood. Antibodies to HCV structural proteins do not appear to play a key role in clearance of the virus and do not persist after recovery. Here, we studied the kinetics of the cellular immune responses of three HCV-recovered chimpanzees during rechallenge with increasing doses of homologous HCV. Although HCV envelope antibodies remained undetectable throughout the rechallenge, all animals mounted rapid HCV-specific T-cell responses. The pattern of the cellular immune response in blood and liver correlated with the virological outcome. The animal that most rapidly cleared circulating HCV as determined by nested reverse transcription-PCR (RT-PCR) displayed the most vigorous and sustained response of gamma interferon (IFN-γ)-producing and proliferating CD4+ T cells in the blood. Vigorous CD4+ T-cell proliferation during viremia was followed by an increased frequency and a phenotypic and functional change of the tetramer+ CD8+ T-cell population. The second animal cleared HCV initially with strong peripheral and intrahepatic CD4+ T-cell responses but experienced low-level HCV recrudescence 12 weeks later, when HCV-specific T cells became undetectable. The third animal maintained minute amounts of circulating HCV, detectable only by nested RT-PCR, in the face of a weak IFN-γ+ T-cell response. Collectively, the results suggest protective rather than sterilizing immunity after recovery from hepatitis C. The rate of HCV clearance following reexposure depends on the cellular immune response, the quality and quantity of which may vary among chimpanzees that recovered from HCV infection.


2007 ◽  
Vol 81 (12) ◽  
pp. 6502-6512 ◽  
Author(s):  
Anju Singh ◽  
Marcel Wüthrich ◽  
Bruce Klein ◽  
M. Suresh

ABSTRACT Despite the well-recognized importance of CD4 T-cell help in the induction of antibody production and cytotoxic-T-lymphocyte responses, the regulation of CD4 T-cell responses is not well understood. Using mice deficient for TNF receptor I (TNFR I) and/or TNFR II, we show that TNFR I and TNFR II play redundant roles in down regulating the expansion of CD4 T cells during an acute infection of mice with lymphocytic choriomeningitis virus (LCMV). Adoptive transfer experiments using T-cell-receptor transgenic CD4 T cells and studies with mixed bone marrow chimeras indicated that indirect effects and not direct effects on T cells mediated the suppressive function of TNF on CD4 T-cell expansion during the primary response. Further studies to characterize the indirect effects of TNF suggested a role for TNFRs in LCMV-induced deletion of CD11chi dendritic cells in the spleen, which might be a mechanism to limit the duration of antigenic stimulation and CD4 T-cell expansion. Consequent to enhanced primary expansion, there was a substantial increase in the number of LCMV-specific memory CD4 T cells in the spleens of mice deficient for both TNFR I and TNFR II. In summary, our findings suggest that TNFRs down regulate CD4 T-cell responses during an acute LCMV infection by a non-T-cell autonomous mechanism.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 594-594
Author(s):  
Ronjon Chakraverty ◽  
Jennifer Buchli ◽  
Guiling Zhao ◽  
Megan Sykes

Abstract Donor leucocyte infusions (DLI) given to established mixed chimeras (MC) can eliminate normal and malignant hematopoietic cells without causing graft-versus-host disease (GVHD). DLI given immediately following lethal irradiation lead to severe GVHD. We examined the proliferation, expansion, differentiation and survival of GVH-reactive T cells following delayed DLI and compared the outcomes to those observed when identical DLI were administered early following lethal irradiation (TBI). MC recipients were prepared by TBI of BALB/c mice and reconstitution with mixed BALB/c and CD45.2 C57BL/6 (B6) T-cell depleted bone marrow (TCD BM). 10 weeks later, we transferred 1 x 107 CD45.1 B6 and 5 x 106 2C transgenic (tg) splenocytes. CD8+ T cells from 2C tg mice bear TCR specific for recipient class I MHC Ld. Polyclonal DLI-derived CD4+/CD8+ T cell responses were monitored by gating on CD45.1+ events and clonal 2C CD8+ T cell responses tracked using a clonotypic marker. For comparison, identical DLI together with TCD BM was administered to freshly irradiated BALB/c or B6 CD45.2 syngeneic recipients. MC recipients of delayed DLI developed a GVH reaction, as indicated by increases in donor chimerism, but no GVHD. In contrast, allogeneic recipients receiving DLI immediately following TBI developed lethal GVHD (median survival 32d vs. >100d post-delayed DLI, p<0.0001). By day 6, donor CD4+/CD8+ T cells had undergone almost equivalent proliferation as monitored by CFSE-dilution in MC and TBI allogeneic recipients. However, the kinetics and distribution of donor T cell expansion were distinct. Following delayed DLI, marked expansion of donor CD4+ cells (peak day 10) preceded expansion of CD8+ cells (peak day 13) in the spleen, with less accumulation in the lymph nodes, BM, liver and lung, and no accumulation in the gut. Histology revealed transient, mild lymphocytic infiltrates within the lung/liver but no evidence of colitis. In contrast, the kinetics of donor CD4+/CD8+ T cell expansion were more rapid in freshly irradiated recipients with CD4+/CD8+ responses peaking on day 4–7. The distribution was also different with major increases in donor CD4+/CD8+ numbers in the gut but less accumulation in the spleen. Histology confirmed severe colitis. The kinetics of proliferation, expansion and distribution of tg 2C CD8+ T cells showed a similar pattern to the polyclonal donor CD8+ T cell population. Following delayed DLI, 2C CD8+ T cells acquired a memory/activation phenotype (CD44hi, CD45RBlo, CD62Llo, CD49d+, CD27+) with similar kinetics to those observed in TBI mice developing GVHD. Despite the marked differences in trafficking to the gut, 2C CD8+ T cells in both groups of allogeneic recipients expressed equivalent levels of the gut homing receptor, α4β7. However, we also observed important differences: 1) IL-2Rαexpression was absent on 2C CD8+ T cells following delayed DLI, but was expressed at high levels (>50% by day +3) in freshly irradiated DLI recipients; 2) 2C CD8+ T cells showed greater reductions in expression of IL-7Rαfollowing delayed DLI; and 3) high rates of 2C CD8+ T cell apoptosis, as indicated by annexin V staining, were observed following delayed DLI with absolute numbers up to 6-fold greater than in TBI recipients. Thus, in contrast to responses in freshly irradiated mice that develop GVHD, GVH reactions induced by delayed DLI are characterized by delayed kinetics, a distinct distribution, marked apoptosis and reduced expression of cytokine receptors important for CD8+ T-cell survival.


2002 ◽  
Vol 76 (9) ◽  
pp. 4251-4259 ◽  
Author(s):  
Fernando Rodriguez ◽  
Stephanie Harkins ◽  
Mark K. Slifka ◽  
J. Lindsay Whitton

ABSTRACT The phenomenon whereby the host immune system responds to only a few of the many possible epitopes in a foreign protein is termed immunodominance. Immunodominance occurs not only during microbial infection but also following vaccination, and clarification of the underlying mechanism may permit the rational design of vaccines which can circumvent immunodominance, thereby inducing responses to all epitopes, dominant and subdominant. Here, we show that immunodominance affects DNA vaccines and that the effects can be avoided by the simple expedient of epitope separation. DNA vaccines encoding isolated dominant and subdominant epitopes induce equivalent responses, confirming a previous demonstration that coexpression of dominant and subdominant epitopes on the same antigen-presenting cell (APC) is central to immunodominance. We conclude that multiepitope DNA vaccines should comprise a cocktail of plasmids, each with its own epitope, to allow maximal epitope dispersal among APCs. In addition, we demonstrate that subdominant responses are actively suppressed by dominant CD8+ T-cell responses and that gamma interferon (IFN-γ) is required for this suppression. Furthermore, priming of CD8+ T cells to a single dominant epitope results in strong suppression of responses to other normally dominant epitopes in immunocompetent mice, in effect rendering these epitopes subdominant; however, responses to these epitopes are increased 6- to 20-fold in mice lacking IFN-γ. We suggest that, in agreement with our previous observations, IFN-γ secretion by CD8+ T cells is highly localized, and we propose that its immunosuppressive effect is focused on the APC with which the dominant CD8+ T cell is in contact.


1999 ◽  
Vol 67 (11) ◽  
pp. 5604-5614 ◽  
Author(s):  
Yupin Charoenvit ◽  
Victoria Fallarme Majam ◽  
Giampietro Corradin ◽  
John B. Sacci ◽  
Ruobing Wang ◽  
...  

ABSTRACT Most work on protective immunity against the pre-erythrocytic stages of malaria has focused on induction of antibodies that prevent sporozoite invasion of hepatocytes, and CD8+ T-cell responses that eliminate infected hepatocytes. We recently reported that immunization of A/J mice with an 18-amino-acid synthetic linear peptide from Plasmodium yoelii sporozoite surface protein 2 (SSP2) in TiterMax adjuvant induces sterile protection that is dependent on CD4+ T cells and gamma interferon (IFN-γ). We now report that immunization of inbred A/J mice and outbred CD1 mice with each of two linear synthetic peptides from the 17-kDa P. yoelii hepatocyte erythrocyte protein (HEP17) in the same adjuvant also induces protection against sporozoite challenge that is dependent on CD4+ T cells and IFN-γ. The SSP2 peptide and the two HEP17 peptides are recognized by B cells as well as T cells, and the protection induced by these peptides appears to be directed against the infected hepatocytes. In contrast to the peptide-induced protection, immunization of eight different strains of mice with radiation-attenuated sporozoites induces protection that is absolutely dependent on CD8+ T cells. Data represented here demonstrate that CD4+ T-cell-dependent protection can be induced by immunization with linear synthetic peptides. These studies therefore provide the foundation for an approach to pre-erythrocytic-stage malaria vaccine development, based on the induction of protective CD4+ T-cell responses, which will complement efforts to induce protective antibody and CD8+T-cell responses.


2021 ◽  
Author(s):  
Kyla D Omilusik ◽  
Marija S Nadjsombati ◽  
Tomomi M Yoshida ◽  
Laura A Shaw ◽  
John Goulding ◽  
...  

AbstractT cells are essential mediators of the immune responses against infectious diseases and provide long-lived protection from reinfection. The differentiation of naive T cells to effector T cells and subsequent differentiation and persistence of memory T cell populations in response to infection is a highly regulated process. E protein transcription factors and their inhibitors, Id proteins, are important regulators of both CD4+ and CD8+ T cell responses; however, their regulation at the protein level has not been explored. Recently, the deubiquitinase USP1 was shown to stabilize Id2 and modulate cellular differentiation in osteosarcomas. Here, we investigated a role for Usp1 in posttranslational control of Id2 and Id3 in T cells. We show that Usp1 was upregulated in T cells following activation in vitro or following infection in vivo, and the extent of Usp1 expression correlated with the degree of T cell expansion. Usp1 directly interacted with Id2 and Id3 following T cell activation. However, Usp1-deficiency did not impact Id protein abundance in effector T cells or alter effector CD8+ T cell expansion or differentiation following a primary infection. Usp1 deficiency did result in a gradual loss of memory cells over time and impaired accumulation and altered differentiation following a secondary infection. Together, these results identify Usp1 as a player in modulating recall responses at the protein level and highlight differences in regulation of T cell responses between primary and subsequent infection encounters. Finally, our observations reveal that differential regulation of Id2/3 proteins between immune vs non-immune cell types.


2009 ◽  
Vol 77 (5) ◽  
pp. 1894-1903 ◽  
Author(s):  
Jodie S. Haring ◽  
John T. Harty

ABSTRACT Proinflammatory cytokines, such as gamma interferon (IFN-γ), impact aspects of T-cell responses after infection, including expansion, contraction, and memory formation. Interleukin-18 (IL-18) functions as a proinflammatory cytokine by stimulating the production of IFN-γ from multiple cell types and accentuating the development of Th1 CD4 T-cell responses. Focused microarray analyses revealed upregulation of IL-18 and IL-18 receptor genes in CD8 T cells during the contraction phase. Based on these findings we investigated if and how signaling through the IL-18 receptor influences the development and kinetics of antigen (Ag)-specific CD8 and CD4 T-cell responses following infection. IL-18Rα−/− and IL-18−/− mice developed frequencies and total numbers of Ag-specific CD8 T cells after Listeria monocytogenes infection that were similar to those of wild-type C57BL/6 mice. The kinetics of expansion, contraction, and memory CD8 T-cell maintenance were also similar. When IL-18Rα deficiency was isolated to Ag-specific CD8 T cells, the kinetics of the expansion and contraction phases were also normal. These basic findings were confirmed by examining the response to vaccinia virus infection. In contrast, the expansion of Ag-specific CD4 T cells was slightly curtailed by the absence of IL-18Rα; however, contraction and the maintenance of memory were not altered. Importantly, both memory Ag-specific CD8 and CD4 T cells generated in the absence of IL-18Rα expanded appropriately after secondary antigen exposure and were protective, indicating that signaling through the IL-18 receptor is not required for normal T-cell response kinetics and survival of immunized mice challenged with a lethal L. monocytogenes infection.


2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Pritesh Desai ◽  
Vikas Tahiliani ◽  
Georges Abboud ◽  
Jessica Stanfield ◽  
Shahram Salek-Ardakani

ABSTRACTRespiratory infection with vaccinia virus (VacV) elicits robust CD8+T cell responses that play an important role in host resistance. In the lung, VacV encounters multiple tissue-resident antigen-presenting cell (APC) populations, but which cell plays a dominant role in priming of virus-specific CD8+effector T cell responses remains poorly defined. We used Batf3−/−mice to investigate the impact of CD103+and CD8α+dendritic cell (DC) deficiency on anti-VacV CD8+T cell responses. We found that Batf3−/−mice were more susceptible to VacV infection, exhibiting profound weight loss, which correlated with impaired accumulation of gamma interferon (IFN-γ)-producing CD8+T cells in the lungs. This was largely due to defective priming since early in the response, antigen-specific CD8+T cells in the draining lymph nodes of Batf3−/−mice expressed significantly reduced levels of Ki67, CD25, and T-bet. These results underscore a specific role for Batf3-dependent DCs in regulating priming and expansion of effector CD8+T cells necessary for host resistance against acute respiratory VacV infection.IMPORTANCEDuring respiratory infection with vaccinia virus (VacV), a member ofPoxviridaefamily, CD8+T cells play important role in resolving the primary infection. Effector CD8+T cells clear the virus by accumulating in the infected lungs in large numbers and secreting molecules such as IFN-γ that kill virally infected cells. However, precise cell types that regulate the generation of effector CD8+T cells in the lungs are not well defined. Dendritic cells (DCs) are a heterogeneous population of immune cells that are recognized as key initiators and regulators of T-cell-mediated immunity. In this study, we reveal that a specific subset of DCs that are dependent on the transcription factor Batf3 for their development regulate the magnitude of CD8+T cell effector responses in the lungs, thereby providing protection during pulmonary VacV infection.


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.


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