Human rhinovirus-specific CD8 T cell responses target conserved and unusual epitopes

Abstract

Human Rhinovirus (HRV) is a major cause of common cold, bronchiolitis, and exacerbations of chronic pulmonary diseases such as asthma. CD8 T cell responses likely play an important role in the control of HRV infection but, surprisingly, HRV-specific CD8 T cell epitopes remain yet to be identified. Here, we approached the discovery and characterization of conserved HRV-specific CD8 T cell epitopes from species A (HRV A) and C (HRV C), the most frequent subtypes in the clinics of various pulmonary diseases. We found IFNγ-ELISPOT positive responses to 23 conserved HRV-specific peptides on peripheral blood mononuclear cells (PBMCs) from 14 HLA I typed subjects. Peptide-specific IFNγ production by CD8 T cells and binding to the relevant HLA I were confirmed for six HRV A-specific and three HRV C-specific CD8 T cell epitopes. In addition, we validated A*02:01-restricted epitopes by DimerX staining and found out that these peptides mediated cytotoxicity. All these A*02:01-restricted epitopes were 9-mers but, interestingly, we also identified and validated an unusually long 16-mer epitope peptide restricted by A*02:01, HRVC1791-1806 (GLEPLDLNTSAGFPYV). HRV-specific CD8 T cell epitopes describe here are expected to elicit CD8 T cell responses in up to 87% of the population and could be key for developing an HRV vaccine.