Peptides generated by proteasome-catalyzed splicing of noncontiguous amino acid sequences have been shown to constitute a source of nontemplated human leukocyte antigen class I (HLA-I) epitopes, but their role in pathogen-specific immunity remains unknown. CD8+ T cells are key mediators of HIV type 1 (HIV-1) control, and identification of novel epitopes to enhance targeting of infected cells is a priority for prophylactic and therapeutic strategies. To explore the contribution of proteasome-catalyzed peptide splicing (PCPS) to HIV-1 epitope generation, we developed a broadly applicable mass spectrometry-based discovery workflow that we employed to identify spliced HLA-I-bound peptides on HIV-infected cells. We demonstrate that HIV-1-derived spliced peptides comprise a relatively minor component of the HLA-I-bound viral immunopeptidome. Although spliced HIV-1 peptides may elicit CD8+ T cell responses relatively infrequently during infection, CD8+ T cells primed by partially overlapping contiguous epitopes in HIV-infected individuals were able to cross-recognize spliced viral peptides, suggesting a potential role for PCPS in restricting HIV-1 escape pathways. Vaccine-mediated priming of responses to spliced HIV-1 epitopes could thus provide a novel means of exploiting epitope targets typically underutilized during natural infection.
Journal article
2019-12-01T00:00:00+00:00
116
24748 - 24759
11
Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7FZ, United Kingdom; wayne.paes@ndm.ox.ac.uk nicola.ternette@ndm.ox.ac.uk persephone.borrow@ndm.ox.ac.uk.
CD8-Positive T-Lymphocytes, Cell Line, Humans, HIV-1, HIV Infections, Proteasome Endopeptidase Complex, Peptides, Viral Proteins, RNA, Viral, AIDS Vaccines, Histocompatibility Antigens Class I, Antigens, Viral, Epitopes, T-Lymphocyte, Cohort Studies, Cross Reactions, Cross-Priming, RNA Splicing, Immune Evasion, Datasets as Topic, RNA-Seq