CD8+ T cell-based strong selective pressure on multiple simian immunodeficiency virus targets in macaques possessing a protective MHC class I haplotype

2019 ◽  
Vol 512 (2) ◽  
pp. 213-217
Author(s):  
Trang Thi Thu Hau ◽  
Midori Nakamura-Hoshi ◽  
Yoshiaki Kanno ◽  
Takushi Nomura ◽  
Masako Nishizawa ◽  
...  
Keyword(s):  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Mhc Class I ◽  
Selective Pressure ◽  
Cd8 T Cell ◽  
Class I ◽  
Strong Selective Pressure ◽  
Immunodeficiency Virus

scholarly journals Infection with “Escaped” Virus Variants Impairs Control of Simian Immunodeficiency Virus SIVmac239 Replication in Mamu-B*08-Positive Macaques

2009 ◽  
Vol 83 (22) ◽  
pp. 11514-11527 ◽  
Author(s):  
Laura E. Valentine ◽  
John T. Loffredo ◽  
Alex T. Bean ◽  
Enrique J. León ◽  
Caitlin E. MacNair ◽  
...  
Keyword(s):  
T Cell ◽  
Viral Replication ◽  
Simian Immunodeficiency Virus ◽  
Mhc Class I ◽  
T Cell Responses ◽  
Class I ◽  
Wild Type ◽  
Viral Loads ◽  
Cell Responses ◽  
Immunodeficiency Virus

ABSTRACT An understanding of the mechanism(s) by which some individuals spontaneously control human immunodeficiency virus (HIV)/simian immunodeficiency virus replication may aid vaccine design. Approximately 50% of Indian rhesus macaques that express the major histocompatibility complex (MHC) class I allele Mamu-B*08 become elite controllers after infection with simian immunodeficiency virus SIVmac239. Mamu-B*08 has a binding motif that is very similar to that of HLA-B27, a human MHC class I allele associated with the elite control of HIV, suggesting that SIVmac239-infected Mamu-B*08-positive (Mamu-B*08+ ) animals may be a good model for the elite control of HIV. The association with MHC class I alleles implicates CD8+ T cells and/or natural killer cells in the control of viral replication. We therefore introduced point mutations into eight Mamu-B*08-restricted CD8+ T-cell epitopes to investigate the contribution of epitope-specific CD8+ T-cell responses to the development of the control of viral replication. Ten Mamu-B*08 + macaques were infected with this mutant virus, 8X-SIVmac239. We compared immune responses and viral loads of these animals to those of wild-type SIVmac239-infected Mamu-B*08 + macaques. The five most immunodominant Mamu-B*08-restricted CD8+ T-cell responses were barely detectable in 8X-SIVmac239-infected animals. By 48 weeks postinfection, 2 of 10 8X-SIVmac239-infected Mamu-B*08+ animals controlled viral replication to <20,000 viral RNA (vRNA) copy equivalents (eq)/ml plasma, while 10 of 15 wild-type-infected Mamu-B*08+ animals had viral loads of <20,000 vRNA copy eq/ml (P = 0.04). Our results suggest that these epitope-specific CD8+ T-cell responses may play a role in establishing the control of viral replication in Mamu-B*08 + macaques.

scholarly journals Mauritian Cynomolgus Macaques Share Two Exceptionally Common Major Histocompatibility Complex Class I Alleles That Restrict Simian Immunodeficiency Virus-Specific CD8+ T Cells

2009 ◽  
Vol 83 (12) ◽  
pp. 6011-6019 ◽  
Author(s):  
Benjamin J. Burwitz ◽  
Chad J. Pendley ◽  
Justin M. Greene ◽  
Ann M. Detmer ◽  
Jennifer J. Lhost ◽  
...  
Keyword(s):  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Mhc Class I ◽  
Nonhuman Primate ◽  
T Cell Responses ◽  
Class I ◽  
Major Histocompatibility ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Cynomolgus Macaques

ABSTRACT Vaccines that elicit CD8+ T-cell responses are routinely tested for immunogenicity in nonhuman primates before advancement to clinical trials. Unfortunately, the magnitude and specificity of vaccine-elicited T-cell responses are variable in currently utilized nonhuman primate populations, owing to heterogeneity in major histocompatibility (MHC) class I genetics. We recently showed that Mauritian cynomolgus macaques (MCM) have unusually simple MHC genetics, with three common haplotypes encoding a shared pair of MHC class IA alleles, Mafa-A*25 and Mafa-A*29. Based on haplotype frequency, we hypothesized that CD8+ T-cell responses restricted by these MHC class I alleles would be detected in nearly all MCM. We examine here the frequency and functionality of these two alleles, showing that 88% of MCM express Mafa-A*25 and Mafa-A*29 and that animals carrying these alleles mount three newly defined simian immunodeficiency virus-specific CD8+ T-cell responses. The epitopes recognized by each of these responses accumulated substitutions consistent with immunologic escape, suggesting these responses exert antiviral selective pressure. The demonstration that Mafa-A*25 and Mafa-A*29 restrict CD8+ T-cell responses that are shared among nearly all MCM indicates that these animals are an advantageous nonhuman primate model for comparing the immunogenicity of vaccines that elicit CD8+ T-cell responses.

scholarly journals High-throughput identification of MHC class I binding peptides using an ultradense peptide array

2019 ◽  
Author(s):  
Amelia K. Haj ◽  
Meghan E. Breitbach ◽  
David A. Baker ◽  
Mariel S. Mohns ◽  
Gage K. Moreno ◽  
...  
Keyword(s):  
T Cell ◽  
Mhc Class I ◽  
High Throughput ◽  
Vaccine Development ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Class I ◽  
Peptide Array ◽  
Cell Responses ◽  
Immunodeficiency Virus

AbstractRational vaccine development and evaluation requires identifying and measuring the magnitude of epitope-specific CD8 T cell responses. However, conventional CD8 T cell epitope discovery methods are labor-intensive and do not scale well. Here, we accelerate this process by using an ultradense peptide array as a high-throughput tool for screening peptides to identify putative novel epitopes. In a single experiment, we directly assess the binding of four common Indian rhesus macaque MHC class I molecules – Mamu-A1*001, -A1*002, -B*008, and -B*017 – to approximately 61,000 8-mer, 9-mer, and 10-mer peptides derived from the full proteomes of 82 simian immunodeficiency virus (SIV) and simian-human immunodeficiency virus (SHIV) isolates. Many epitope-specific CD8 T cell responses restricted by these four MHC molecules have already been identified in SIVmac239, providing an ideal dataset for validating the array; up to 64% of these known epitopes are found in the top 192 SIVmac239 peptides with the most intense MHC binding signals in our experiment. To assess whether the peptide array identified putative novel CD8 T cell epitopes, we validated the method by IFN-γ ELISPOT assay and found three novel peptides that induced CD8 T cell responses in at least two Mamu-A1*001-positive animals; two of these were validated by ex vivo tetramer staining. This high-throughput identification of peptides that bind class I MHC will enable more efficient CD8 T cell response profiling for vaccine development, particularly for pathogens with complex proteomes where few epitope-specific responses have been defined.

608 Immunodominant listeria epitopes compete with vaccine-directed cd8+ t-cell responses rescued by peptide-MHC stabilizing modifications

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A644-A644
Author(s):  
John Flickinger ◽  
Jagmohan Singh ◽  
Yanki Yarman ◽  
Robert Carlson ◽  
Scott Waldman ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
T Cell ◽  
Cell Line ◽  
Mhc Class I ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Class I ◽  
Peptide Ligand ◽  
Altered Peptide Ligand ◽  
Cell Responses

BackgroundThe Gram-positive bacterium Listeria monocytogenes (Lm) is a promising vector for cancer immunotherapy due to its ability to directly infect antigen-presenting cells, induce potent CD8+ T-cell immunity, and remodel immunosuppressive tumor microenvironments.1 Recent clinical trials have demonstrated safety and immunogenicity of Lm-based cancer vaccines in lung, cervical, pancreatic, and other cancers. In colorectal cancer, the transmembrane receptor guanylyl cyclase C (GUCY2C) is an emerging target for immunotherapy.2 Here, we examined the immunogenicity of a recombinant strain of Listeria monocytogenes secreting GUCY2C (Lm-GUCY2C). Surprisingly, Lm-GUCY2C vaccination induced robust Lm-specific CD8+ T-cell immunity but failed to prime GUCY2C-specific CD8+ T-cell responses. These studies explore the hypothesis that immunodominant Lm antigens suppress primary immunity to subdominant GUCY2C epitopes in Lm-GUCY2CMethodsLm-GUCY2C expresses the extracellular domain of mouse GUCY2C23-429 downstream of an ActA promoter integrated into the genome of the live, attenuated delta actA delta inlB Lm strain. Altered peptide ligands were designed based on NetMHCpan 4.0 peptide-MHC binding algorithms and similarly cloned into Lm. Peptide-MHC class I complex stability was quantified by FACS-based surface peptide-MHC dissociation on the TAP-deficient cell line, RMA-S H-2Kd.3In vivo efficacy studies employed IFNγ-ELISpot quantification of T-cell responses and tumor challenge studies with the CT26 colorectal cancer cell line. Adenovirus expressing GUCY2C was used as a positive control.2 4ResultsLm-GUCY2C vaccination of BALB/c mice generated Lm-specific CD8+ T-cell responses but an absence of GUCY2C-specific immunity. Peptide-MHC stability studies revealed poor stability of the dominant GUCY2C254-262 epitope complexed with H-2Kd compared to H-2Kd-restricted Lm epitopes derived from the LLO and p60 Lm antigens. Mutation of the GUCY2C254-262 peptide at critical anchoring residues for binding H-2Kd revealed that the altered peptide ligand with an F255Y mutation significantly improved the stability of the GUCY2C254-262-H-2Kd complex. Similarly, vaccination of mice with recombinant Lm-GUCY2C expressing the altered peptide ligand (Lm-GUCY2CF255Y) restored GUCY2C immunogenicity and antitumor immunity.ConclusionsImmunodominant Lm antigens may interfere with immune responses directed to the vaccine target antigen GUCY2C by competing with GUCY2C epitope for MHC class I binding and presentation. Moreover, use of a substituted GUCY2C -peptide ligand with enhanced peptide-MHC class I stability restored GUCY2C-specific immunity in the context of Lm-GUCY2C, an approach that can be translated to patients. Importantly, these studies also suggest that ongoing Lm-based vaccine development programs targeting a variety of antigens in other cancer types may be similarly limited by the immunodominance of Lm epitopes.AcknowledgementsThe authors thank Dr. Peter Lauer for providing the pPL2 integration vector used in cloning Lm-GUCY2C and Dr. Sean Murphy for providing the RMA-S H-2Kd cell line.Ethics ApprovalStudies were approved by the Thomas Jefferson University IACUC (Protocol # 01956).ReferencesFlickinger JC, Rodeck U, Snook AE. Listeria monocytogenes as a Vector for Cancer Immunotherapy: Current Understanding and Progress. Vaccines (Basel) 2018;6. doi:10.3390/vaccines6030048.Snook AE, Baybutt TR, Xiang B, Abraham TS, Flickinger JC, Hyslop T, et al. Split tolerance permits safe Ad5-GUCY2C-PADRE vaccine-induced T-cell responses in colon cancer patients. J Immunother Cancer 2019;7:104. doi:10.1186/s40425-019-0576-2.Müllbacher A, Lobigs M, Kos FJ, Langman R. Alloreactive cytotoxic T-cell function, peptide nonspecific. Scand J Immunol 1999;49:563–9.Flickinger J. JC, Singh J, Carlson R, Leong E, Baybutt T, Barton J, et al. Chimeric Ad5.F35 vector evades anti-adenovirus serotype 5 neutralization opposing GUCY2C-targeted antitumor immunity. J Immunother Cancer 2020.

Natural CD8 + T-cell responses against MHC class I epitopes of the HER-2/ neu oncoprotein in patients with epithelial tumors

2003 ◽  
Vol 52 (12) ◽  
pp. 771-779 ◽  
Author(s):  
Panagiota A. Sotiropoulou ◽  
Sonia A. Perez ◽  
Volfgang Voelter ◽  
Hartmut Echner ◽  
Ioannis Missitzis ◽  
...  
Keyword(s):  
T Cell ◽  
Mhc Class I ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Class I ◽  
Cell Responses ◽  
Epithelial Tumors ◽  
Her 2
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