Breadth of CD8 T-cell mediated inhibition of replication of diverse HIV-1 transmitted-founder isolates correlates with the breadth of recognition within a comprehensive HIV-1 Gag, Nef, Env and Pol potential T-cell epitope (PTE) peptide set

• Published in: PloS one Vol. 16; no. 11; p. e0260118
• Main Authors: Hayes, Peter, Fernandez, Natalia, Ochsenbauer, Christina, Dalel, Jama, Hare, Jonathan, King, Deborah, Black, Lucas, Streatfield, Claire, Kakarla, Vanaja, Macharia, Gladys, Makinde, Julia, Price, Matt, Hunter, Eric, Gilmour, Jill
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 17.11.2021; Public Library of Science (PLoS)
• Subjects: Adult; Amino acids; Analysis; Antibodies; Antigenic determinants; Antiretroviral drugs; Antiviral drugs; Biology and Life Sciences; CD3 antigen; CD4 antigen; CD8 antigen; CD8-Positive T-Lymphocytes - immunology; Diagnosis; Enzyme-linked immunosorbent assay; Epitopes; Epitopes, T-Lymphocyte - immunology; Female; gag Gene Products, Human Immunodeficiency Virus - immunology; Gag protein; Health aspects; HIV; HIV (Viruses); HIV Infections - immunology; HIV Infections - virology; HIV-1 - immunology; Human immunodeficiency virus; Humans; Immunology; Infections; Laboratories; Lymphocytes T; Male; Medicine and Health Sciences; nef Gene Products, Human Immunodeficiency Virus - immunology; Peptides; Peptides - immunology; Peripheral blood mononuclear cells; Properties; Recognition; Replication; Research and Analysis Methods; Supervision; T cells; Vaccines; Virus Replication - drug effects; γ-Interferon; United States; New York; San Francisco California; California; United Kingdom > UK; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0260118

Full characterisation of functional HIV-1-specific T-cell responses, including identification of recognised epitopes linked with functional antiviral responses, would aid development of effective vaccines but is hampered by HIV-1 sequence diversity. Typical approaches to identify T-cell epitopes utilising extensive peptide sets require subjects’ cell numbers that exceed feasible sample volumes. To address this, CD8 T-cells were polyclonally expanded from PBMC from 13 anti-retroviral naïve subjects living with HIV using CD3/CD4 bi-specific antibody. Assessment of recognition of individual peptides within a set of 1408 HIV-1 Gag, Nef, Pol and Env potential T-cell epitope peptides was achieved by sequential IFNγ ELISpot assays using peptides pooled in 3-D matrices followed by confirmation with single peptides. A Renilla reniformis luciferase viral inhibition assay assessed CD8 T-cell-mediated inhibition of replication of a cross-clade panel of 10 HIV-1 isolates, including 9 transmitted-founder isolates. Polyclonal expansion from one frozen PBMC vial provided sufficient CD8 T-cells for both ELISpot steps in 12 of 13 subjects. A median of 33 peptides in 16 epitope regions were recognised including peptides located in previously characterised HIV-1 epitope-rich regions. There was no significant difference between ELISpot magnitudes for in vitro expanded CD8 T-cells and CD8 T-cells directly isolated from PBMCs. CD8 T-cells from all subjects inhibited a median of 7 HIV-1 isolates (range 4 to 10). The breadth of CD8 T-cell mediated HIV-1 inhibition was significantly positively correlated with CD8 T-cell breadth of peptide recognition. Polyclonal CD8 T-cell expansion allowed identification of HIV-1 isolates inhibited and peptides recognised within a large peptide set spanning the major HIV-1 proteins. This approach overcomes limitations associated with obtaining sufficient cell numbers to fully characterise HIV-1-specific CD8 T-cell responses by different functional readouts within the context of extreme HIV-1 diversity. Such an approach will have useful applications in clinical development for HIV-1 and other diseases.