scholarly journals Kinetics of CD4+ and CD8+ Memory T-Cell Responses during Hepatitis C Virus Rechallenge of Previously Recovered Chimpanzees

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.

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.


2007 ◽  
Vol 81 (11) ◽  
pp. 5882-5892 ◽  
Author(s):  
Nadia Alatrakchi ◽  
Camilla S. Graham ◽  
Hans J. J. van der Vliet ◽  
Kenneth E. Sherman ◽  
Mark A. Exley ◽  
...  

ABSTRACT Hepatitis C virus (HCV)-specific T-cell responses are rarely detected in peripheral blood, especially in the presence of human immunodeficiency virus (HIV) coinfection. Based on recent evidence that T-regulatory cells may be increased in chronic HCV, we hypothesized that functional blockade of regulatory cells could raise HCV-specific responses and might be differentially regulated in the setting of HIV coinfection. Three groups of subjects were studied: HCV monoinfected, HCV-HIV coinfected, and healthy controls. Frequencies of peripheral T cells specific for peptides derived from HCV core, HIV type 1 p24, and recall antigens were analyzed by gamma interferon (IFN-γ) enzyme-linked immunospot assay. HCV-specific T-cell responses were very weak in groups with HCV and HCV-HIV infections. Addition of blocking antibodies against transforming growth factor β1 (TGF-β1), -2, and -3 and interleukin-10 specifically increased the HCV-specific T-cell responses in both infected groups; however, this increase was attenuated in the group with HCV-HIV coinfection compared to HCV infection alone. No increase in recall antigen- or HIV-specific responses was observed. Flow cytometric sorter analysis demonstrated that regulatory-associated cytokines were produced by HCV-specific CD3+CD8+CD25− cells. Enhancement of the IFN-γ effect was observed for both CD4 and CD8 T cells and was mediated primarily by TGF-β1, -2, and -3 neutralization. In conclusion, blockade of TGF-β secretion could enhance peripheral HCV-specific T-cell responses even in the presence of HIV coinfection.


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.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A469-A469
Author(s):  
Bernard Fox ◽  
Tarsem Moudgil ◽  
Traci Hilton ◽  
Noriko Iwamoto ◽  
Christopher Paustian ◽  
...  

BackgroundOutcomes for recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) are dismal and responses to anti-PD-1 appear best in tumors with PD-1+ T cells in proximity to PD-L1+ cells, arguing that improved outcome is associated with a pre-existing anti-cancer immune response. Based on this, we hypothesize that vaccines which prime and/or expand T cells to a spectrum of antigens overexpressed by HNSCC combined with T cell agonists, like anti-GITR, that provide costimulatory signals will improve the anti-PD-1 response rates. We have developed a cancer vaccine, DPV-001, that contains more than 300 proteins for genes overexpressed by HNSCC, encapsulated in a CLEC9A-targeted microvesicle and containing TLR/NOD agonists and DAMPs. Recently, we reported that combining anti-GITR + vaccine + anti-PD-1 augmented therapeutic efficacy in a preclinical model and now plan a phase 1b trial of this combination in patients with advanced HNSCC.MethodsSera from patients receiving DPV-001 as adjuvant therapy for definitively treated NSCLC, were analyzed for IgG responses to human proteins by MAP bead arrays and results compared to TCGA gene expression data sets for HNSCC. HNSCC cell lines were evaluated by RNASeq and peptides were eluted from HLA, analyzed by mass spectroscopy and correlated against MAP bead arrays and TCGA data sets. Tumor-reactive T cells from a vaccinated patient were enriched and expanded, and used in cytokine release assay (CRA) against autologous NSCLC and partially HLA matched allogeneic HNSCC cell lines.ResultsPatients receiving DPV-001 (N=13) made 147 IgG responses to at least 70 proteins for genes overexpressed by HNSCC. Preliminary evaluation of the HNSCC peptidome against the results of MAP bead array identify antigens that are target of a humoral immune response. Additionally, tumor-reactive T cells from DPV-001 vaccinated patient recognize two partially HLA-matched HNSCC targets, but not a mis-matched target.ConclusionsRecent observations from our lab and others have correlated IgG Ab responses with T cell responses to epitopes of the same protein. Based on the data summarized above, we hypothesize that we have induced T cell responses against a broad spectrum of shared cancer antigens that are common among adenocarcinomas and squamous cell cancers. Our planned clinical trial will vaccinate and boost the induced responses by costimulation with anti-GITR and then sequence in delayed anti-PD-1 to relieve checkpoint inhibition. MAP bead arrays and the peptidome library generated above will be used to assess anti-cancer B and T cell responses.Trial RegistrationNCT04470024Ethics ApprovalThe original clinical trial was approved by the Providence Portland Medical Center IRB, approval # 13-046. The proposed clinical trial has not yet been reviewed by the IRB.


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.


2003 ◽  
Vol 77 (9) ◽  
pp. 5464-5474 ◽  
Author(s):  
Katja Nilges ◽  
Hanni Höhn ◽  
Henryk Pilch ◽  
Claudia Neukirch ◽  
Kirsten Freitag ◽  
...  

ABSTRACT Human papillomavirus type 16 (HPV16) E6 and E7 oncoproteins are required for cellular transformation and represent candidate targets for HPV-specific and major histocompatibility complex class I-restricted CD8+-T-cell responses in patients with cervical cancer. Recent evidence suggests that cross-reactivity represents the inherent nature of the T-cell repertoire. We identified HLA-A2 binding HPV16 E7 variant peptides from human, bacterial, or viral origin which are able to drive CD8+-T-cell responses directed against wild-type HPV16 E7 amino acid 11 to 19/20 (E711-19/20) epitope YMLDLQPET(T) in vitro. CD8+ T cells reacting to the HLA-A2-presented peptide from HPV16 E711-19(20) recognized also the HLA-A2 binding peptide TMLDIQPED (amino acids 52 to 60) from the human coronavirus OC43 NS2 gene product. Establishment of coronavirus NS2-specific, HLA-A2-restricted CD8+-T-cell clones and ex vivo analysis of HPV16 E7 specific T cells obtained by HLA-A2 tetramer-guided sorting from PBL or tumor-infiltrating lymphocytes obtained from patients with cervical cancer showed that cross-reactivity with HPV16 E711-19(20) and coronavirus NS252-60 represents a common feature of this antiviral immune response defined by cytokine production. Zero of 10 patients with carcinoma in situ neoplasia and 3 of 18 patients with cervical cancer showed ≥0.1% HPV16 E7-reactive T cells in CD8+ peripheral blood lymphocytes. In vivo priming with HPV16 was confirmed in patients with cervical cancer or preinvasive HPV16-positive lesions using HLA-A2 tetramer complexes loaded with the E6-derived epitope KLPQLCTEL. In contrast, we could not detect E6-reactive T cells in healthy individuals. These data imply that the measurement of the HPV16 E711-19(20) CD8+-T-cell response may reflect cross-reactivity with a common pathogen and that variant peptides may be employed to drive an effective cellular immune response against HPV.


npj Vaccines ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Stefania Capone ◽  
Anthony Brown ◽  
Felicity Hartnell ◽  
Mariarosaria Del Sorbo ◽  
Cinzia Traboni ◽  
...  

Abstract Simian adenoviral and modified vaccinia Ankara (MVA) viral vectors used in heterologous prime-boost strategies are potent inducers of T cells against encoded antigens and are in advanced testing as vaccine carriers for a wide range of infectious agents and cancers. It is unclear if these responses can be further enhanced or sustained with reboosting strategies. Furthermore, despite the challenges involved in MVA manufacture dose de-escalation has not been performed in humans. In this study, healthy volunteers received chimpanzee-derived adenovirus-3 and MVA vaccines encoding the non-structural region of hepatitis C virus (ChAd3-NSmut/MVA-NSmut) 8 weeks apart. Volunteers were then reboosted with a second round of ChAd3-NSmut/MVA-NSmut or MVA-NSmut vaccines 8 weeks or 1-year later. We also determined the capacity of reduced doses of MVA-NSmut to boost ChAd3-NSmut primed T cells. Reboosting was safe, with no enhanced reactogenicity. Reboosting after an 8-week interval led to minimal re-expansion of transgene-specific T cells. However, after a longer interval, T cell responses expanded efficiently and memory responses were enhanced. The 8-week interval regimen induced a higher percentage of terminally differentiated and effector memory T cells. Reboosting with MVA-NSmut alone was as effective as with ChAd3-NSmut/MVA-NSmut. A ten-fold lower dose of MVA (2 × 107pfu) induced high-magnitude, sustained, broad, and functional Hepatitis C virus (HCV)-specific T cell responses, equivalent to standard doses (2 × 108 pfu). Overall, we show that following Ad/MVA prime-boost vaccination reboosting is most effective after a prolonged interval and is productive with MVA alone. Importantly, we also show that a ten-fold lower dose of MVA is as potent in humans as the standard dose.


Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 126
Author(s):  
Lilin Lai ◽  
Nadine Rouphael ◽  
Yongxian Xu ◽  
Amy C. Sherman ◽  
Srilatha Edupuganti ◽  
...  

The cellular immune responses elicited by an investigational vaccine against an emergent variant of influenza (H3N2v) are not fully understood. Twenty-five subjects, enrolled in an investigational influenza A/H3N2v vaccine study, who received two doses of vaccine 21 days apart, were included in a sub-study of cellular immune responses. H3N2v-specific plasmablasts were determined by ELISpot 8 days after each vaccine dose and H3N2v specific CD4+ T cells were quantified by intracellular cytokine and CD154 (CD40 ligand) staining before vaccination, 8 and 21 days after each vaccine dose. Results: 95% (19/20) and 96% (24/25) subjects had pre-existing H3N2v specific memory B, and T cell responses, respectively. Plasmablast responses at Day 8 after the first vaccine administration were detected against contemporary H3N2 strains and correlated with hemagglutination inhibition HAI (IgG: p = 0.018; IgA: p < 0.001) and Neut (IgG: p = 0.038; IgA: p = 0.021) titers and with memory B cell frequency at baseline (IgA: r = 0.76, p < 0.001; IgG: r = 0.74, p = 0.0001). The CD4+ T cells at Days 8 and 21 expanded after prime vaccination and this expansion correlated strongly with early post-vaccination HAI and Neut titers (p ≤ 0.002). In an adult population, the rapid serological response observed after initial H3N2v vaccination correlates with post-vaccination plasmablasts and CD4+ T cell responses.


2008 ◽  
Vol 82 (15) ◽  
pp. 7567-7577 ◽  
Author(s):  
Joana Caetano ◽  
António Martinho ◽  
Artur Paiva ◽  
Beatriz Pais ◽  
Cristina Valente ◽  
...  

ABSTRACT CD8 T cells play a major role in antiviral immune responses. Their importance for progression to chronic hepatitis C and response to treatment are still unclear. To address these issues, hepatitis C virus (HCV)-specific CD8 T-cell responses were monitored, at the single-cell level, using HLA class I pentamers specific for HCV core and HCV NS3 epitopes, in 23 chronically infected patients during treatment with pegylated alpha interferon and ribavirin. Patients who presented a sustained-response to therapy had stronger HCV-specific CD8 T-cell responses at all time points studied. Moreover, there were clear differences in the phenotypes of these cells during therapy: in responder patients, terminally differentiated effector cells increased more rapidly, and their frequency was always higher than in nonresponder patients. Sustained-responder patients also showed a higher frequency of HCV-specific CD8 T cells producing cytotoxic factors. Overall, a late and inefficient differentiation process of HCV-specific CD8 T cells might be associated with lack of response to treatment. A better knowledge of the mechanisms underlying this impairment may be important for the development of new therapeutic strategies to maintain, restore, or increase CD8 T-cell effectiveness in chronic HCV infection.


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