scholarly journals Characteristics of HLA-E Restricted T-Cell Responses and Their Role in Infectious Diseases

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Simone A. Joosten ◽  
Lucy C. Sullivan ◽  
Tom H. M. Ottenhoff

Human HLA-E can, in addition to self-antigens, also present pathogen-derived sequences, which elicit specific T-cell responses. T-cells recognize their antigen presented by HLA-E highly specifically and have unique functional and phenotypical properties. Pathogen specific HLA-E restricted CD8+T-cells are an interesting new player in the field of immunology. Future work should address their exact roles and relative contributions in the immune response against infectious diseases.

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.


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.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1980-1980
Author(s):  
Kimberly Noonan ◽  
Lakshmi Rudraraju ◽  
Anna Ferguson ◽  
Amy Sidorski ◽  
Andrea Casildo ◽  
...  

Abstract Background Prevnar, is a multi-valent conjugate vaccine given to children and adults over 50 for the prevention of Streptococcus pneumonia, otis media and pneumococcal pneumonia. The conjugate in Prevnar is a CRM-197 protein molecule which is a nontoxic recombinant Diphtheria toxin. Prevnar serves as an excellent tool in monitoring overall immune response changes in myeloma patients’ pre and post treatment. Humoral B-cell responses can be measured by antibody responses to the pneumococcal antigens, while T cell responses to CRM-197. Clinical Study We previously conducted a study to determine the efficacy of lenalidomide to augment vaccine specific responses in patients with myeloma. Two cohorts of patients were studied. In cohort A (N=10), the first Prevnar vaccine was given two weeks prior to starting lenalidomide and the second vaccine on day 14 of cycle 2 of lenalidomide. In cohort B (N=7), both Prevnar vaccines were given on lenalidomide (day 14 of cycle 2 and 4). As we previously reported patients in cohort B had an overall better B and T cell response to Prevnar compared to cohort A. These responses were due to an overall change in B and T cell phenotype attained with lenalidomide therapy. Results Prospectively, patients in cohort B also had an unexpected overall increase in disease response and in response duration. In Cohort A only 10% of patients responded to therapy while 60% of patients in Cohort B had a clinical response. The patients with a measurable clinical response had a 5-fold increase in the percentage of tumor specific bone marrow (BM) T cells after two vaccinations with Prevnar whereas the non-responding patients had no increase in tumor specific BM T cells. Parelleling the anti-tumor response, responders showed a 15 fold increase in CRM-197 specific BM T cells after the second vaccination. Patients with no clinical response showed minimal CRM-197 T cell immunity. CRM-197 is a specific inhibitor of HB-EGF; syndecan-1 (CD138) is an HB-EGF co-receptor as well as a marker for myeloma plasma cells. We hypothesized that HB-EGF specific responses produced by vaccination with the Prevnar vaccine, and CRM-197 specifically, may have contributed to the overall increased clinical responses in our clinical trial. Responding patients had a 5-fold increase in HB-EGF specific BM T cells after vaccine 2 while clinical non-responders had no increase in HB-EGF specific BM T cells. T cells specificity for purified HB-EGF correlated with both CRM-197 and tumor specific responses. Finally the myeloma cell lines U266, H929, KMS-11 and KMS-12 co-stained for CD138 and HB-EGF with 47% of CD138+ myeloma cells co-expressing HB-EGF. Conclusions We hypothesize that the CRM-197 moiety of the Prevnar vaccine can prime T cell responses against HB-EGF on plasma cells. This immune response, in turn, weakens the tumor stromal interactions in the tumor microenvironment and potentially enhances the anti-tumor efficacy of immunomodulatory drugs such as lenalidomide. Therefore, Prevnar may possibly serve as a candidate anti-myeloma vaccine. Disclosures: No relevant conflicts of interest to declare.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 21032-21032
Author(s):  
K. N. Heller ◽  
P. G. Steinherz ◽  
C. S. Portlock ◽  
C. Münz

21032 Background: Epstein-Barr virus (EBV) asymptomatically establishes persistent infections in more than 90% of the adult population. However, due to effective immune control, only a minority of infected carriers develops spontaneous EBV-associated lymphomas. Since EBV nuclear antigen-1 (EBNA1) is the only protein expressed in all proliferating EBV infected cells we hypothesize that EBNA1 specific immune response is critical in preventing EBV-positive lymphomas. Methods: After informed consent, peripheral blood from healthy volunteers and lymphoma patients (prior to therapy- no evidence of cytopenia) were stimulated (ex vivo) with overlapping peptides covering the immunogenic EBNA1 (aa400–641) sequence. Frequency of EBNA1-specific T-cells were assessed by intracellular cytokine staining and flow cytometric proliferation assays. Cytokine pattern, surface marker phenotype and functional reactivity against EBV specific and control antigens were analyzed. Results: Patient and volunteer immune responses to control antigens and other viruses were assessed and statistically indistinguishable. EBNA1 specific CD4+ T cell responses were detected among 18 of 20 healthy carriers, and among 10 of 16 patients with EBV-negative lymphoma (relative to healthy volunteers p=0.145 via paired student T test). None of the patients with EBV-positive lymphomas (n=8) had a detectable EBNA1-specific CD4+ T-cell response (p<0.003 relative to healthy volunteers and patients with EBV-negative lymphomas). Conclusions: Healthy volunteers and patients with EBV-negative lymphoma have statistically similar EBNA1-specific CD4+ T cell responses. Although patients with EBV-positive lymphoma have intact immune responses to common viruses and antigens, they selectively lack an EBNA1-specific CD4+ T cell response. An intact EBNA1 specific immune response among patients with EBV-negaitve lymphoma implies that lymphoma is not a cause of a selective immune deficiency. On the contrary, these findings suggest that EBNA1-specific CD4+ T cells are critical in the prevention of EBV mediated lymphomas, and a defect in EBNA1 specific immunity may leave EBV carriers suseptible to EBV-positive lymphomas. EBNA1- specific CD4+ T cell function may be a new target for therapies of EBV-associated malignancies. No significant financial relationships to disclose.


2020 ◽  
Author(s):  
Gaëlle Breton ◽  
Pilar Mendoza ◽  
Thomas Hagglof ◽  
Thiago Y. Oliveira ◽  
Dennis Schaefer-Babajew ◽  
...  

AbstractSARS-CoV-2 is responsible for an ongoing pandemic that affected millions of individuals around the globe. To gain further understanding of the immune response in recovered individuals we measured T cell responses in paired samples obtained an average of 1.3 and 6.1 months after infection from 41 individuals. The data indicate that recovered individuals show persistent polyfunctional SARS-CoV-2 antigen specific memory that could contribute to rapid recall responses. In addition, recovered individuals show enduring immune alterations in relative numbers of CD4+ and CD8+ T cells, expression of activation/exhaustion markers, and cell division.SummaryWe show that SARS-CoV-2 infection elicits broadly reactive and highly functional memory T cell responses that persist 6 months after infection. In addition, recovered individuals show enduring immune alterations in CD4+ and CD8+ T cells compartments.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 3008-3008
Author(s):  
C. L. Slingluff ◽  
G. R. Petroni ◽  
W. C. Olson ◽  
M. E. Smolkin ◽  
M. I. Ross ◽  
...  

3008 Background: GM-CSF administered locally with vaccines can augment T-cell responses in animal models. Human experience with GM-CSF has mostly occurred in uncontrolled or nonrandomized trials. Thus, a multicenter prospective randomized phase II trial was performed to determine whether local administration of GM-CSF augments immunogenicity of a multipeptide vaccine administered in an emulsion with an incomplete Freund's adjuvant (IFA). A second component of the trial was designed to assess whether the vaccine administered in two sites is more immunogenic than in a single site. Methods: 121 eligible and evaluable patients with resected stage IIB-IV melanoma were administered a sequence of multipeptide vaccines, each consisting of 12 MHC Class I-restricted melanoma peptides (12MP) to stimulate CD8+ T cells, plus an HLA-DR restricted tetanus helper peptide to stimulate CD4+ T cells. Peptides were emulsified with IFA, with or without GM-CSF. T cell responses were assessed by IFN-gamma ELIspot assay and tetramer analysis, weekly x 8. Clinical outcome was evaluated for all patients. Results: Vaccination was well-tolerated, and each peptide was immunogenic. Overall CD8+ T-cell response rates to the 12MP (days 1–50), for patients vaccinated with or without GM-CSF were 43% and 75%, respectively (p < 0.001), and response magnitude was almost twice as high in patients without GM-CSF. Class I MHC tetramer analyses corroborated the functional data. There was also a greater CD4+ T-cell response to the tetanus helper peptide without GM-CSF than with it (95% and 77%, respectively, p = 0.005). There was no significant difference in immune response rates by the number of vaccine sites. For the entire patient group, 3-year overall and disease-free survival estimates [95% CI] were 76% [67, 83%] and 52% [43, 61%], respectively. There have been too few events to assess differences in clinical outcome by study arm. Conclusions: High immune response rates were achieved with this multipeptide vaccine, but CD8+ and CD4+ T-cell responses appear to be partially suppressed with addition of GM-CSF. These data challenge the value of local GM-CSF as a vaccine adjuvant in humans. [Table: see text]


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.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A513-A513
Author(s):  
Martin Steinbuck ◽  
Peter DeMuth ◽  
Lochana Seenappa ◽  
Christopher Haqq ◽  
Aniela Jakubowski ◽  
...  

BackgroundThe SARS-CoV-2 pandemic’s public health, economic, and social impacts mandate urgent development of effective vaccines to contain or eradicate infection. To that end, we evaluated a novel amphiphile (AMP) vaccine adjuvant, AMP-CpG, composed of diacyl lipid-modified CpG, admixed with the SARS-CoV-2 Spike-2 receptor binding domain (Spike RBD) protein for immunization (ELI 005) in two mouse models. AMP immunogens are efficiently delivered to lymph nodes, where innate and adaptive immune responses are generated.MethodsFemale, 6 to 8-week-old C57BL/6J and BALB/c mice and 37-week-old C57BL/6J mice received two or more doses of benchmark (alum or CpG) or AMP-modified vaccines, comprised of Spike RBD protein and AMP-CpG adjuvant, subcutaneously injected into the tail base in two-week intervals. Antigen was dose spared to determine if AMP-CpG would maintain the immune response. Cellular immune responses were determined via ELISpot analysis of IFNγ production by splenocytes, intracellular cytokine staining of peripheral blood and lung-resident T-cells, and flowcytometric bead array analysis of Th1/2/17 cytokines. Humoral immune responses were determined via blood serum ELISAs to determine sera antibody binding titers, and pseudoviral neutralization assays for comparison to human convalescent serum.ResultsCompared to alum, AMP immunization induced 29-fold higher antigen-specific T cells which produced multiple Th1 cytokines and trafficked into lung parenchyma. Antibody responses favored Th1 isotypes (IgG2bc, IgG3) and potently neutralized Spike-2-ACE2 receptor binding, with titers >100-fold higher than the natural immune response from convalescent COVID-19 patients; responses were maintained despite 10-fold dose-reduction in Spike antigen. Both cellular and humoral immune responses were preserved in aged mice.ConclusionsELI-005 exhibits the qualities of an optimal SARS-CoV-2 vaccine, which should (1) induce robust and durable CD8+ and CD4+ T cell responses, (2) elicit high magnitude neutralizing antibodies, (3) produce Th1 bias in the elicited antibody and T cell responses, (4) potentially expand pre-existing cross-reactive T cells, (5) enable dose-sparing of required immunogens to improve the speed and cost of broad vaccination campaigns, and (6) be efficacious in elderly populations. These advantages merit clinical translation to SARS-CoV-2 and other protein subunit vaccines.


2011 ◽  
Vol 61 (3) ◽  
pp. 385-396 ◽  
Author(s):  
Bianca Altvater ◽  
Sibylle Pscherer ◽  
Silke Landmeier ◽  
Sareetha Kailayangiri ◽  
Barbara Savoldo ◽  
...  

Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1862
Author(s):  
Alena Reguzova ◽  
Nico Fischer ◽  
Melanie Müller ◽  
Ferdinand Salomon ◽  
Thomas Jaenisch ◽  
...  

Although dengue virus (DENV) affects almost half of the world’s population there are neither preventive treatments nor any long-lasting and protective vaccines available at this time. The complexity of the protective immune response to DENV is still not fully understood. The most advanced vaccine candidates focus specifically on humoral immune responses and the production of virus-neutralizing antibodies. However, results from several recent studies have revealed the protective role of T cells in the immune response to DENV. Hence, in this study, we generated a novel and potent DENV vaccine candidate based on an Orf virus (ORFV, genus Parapoxvirus) vector platform engineered to encode five highly conserved or cross-reactive DENV human leukocyte antigen (HLA)-A*02- or HLA-B*07-restricted epitopes as minigenes (ORFV-DENV). We showed that ORFV-DENV facilitates the in vitro priming of CD8+ T cells from healthy blood donors based on responses to each of the encoded immunogenic peptides. Moreover, we demonstrated that peripheral blood mononuclear cells isolated from clinically confirmed DENV-positive donors stimulated with ORFV-DENV generate cytotoxic T cell responses to at least three of the expressed DENV peptides. Finally, we showed that ORFV-DENV could activate CD8+ T cells isolated from donors who had recovered from Zika virus (ZIKV) infection. ZIKV belongs to the same virus family (Flaviviridae) and has epitope sequences that are homologous to those of DENV. We found that highly conserved HLA-B*07-restricted ZIKV and DENV epitopes induced functional CD8+ T cell responses in PBMCs isolated from confirmed ZIKV-positive donors. In summary, this proof-of-concept study characterizes a promising new ORFV D1701-VrV-based DENV vaccine candidate that induces broad and functional epitope-specific CD8+ T cell responses.


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