Identification of Novel Respiratory Syncytial Virus CD4 and CD8 T Cell Epitopes in C57BL/6 Mice.

Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infection and hospitalization in infants. It is well established that both CD4 and CD8 T cells are critical for mediating viral clearance but also contribute to the induction of immunopathology following RSV infection. C57BL/6 mice are often used to study T cell responses following RSV infection given the wide variety of genetically modified animals available. To date, few RSV-derived CD4 and CD8 T cell epitopes have been identified in C57BL/6 mice. Using an overlapping peptide library spanning the entire RSV proteome, intracellular cytokine staining for IFN-γ was performed to identify novel CD4 and CD8 T cell epitopes in C57BL/6 mice. We identified two novel CD4 T cell epitopes and three novel CD8 T cell epitopes located within multiple RSV proteins. Additionally, we characterized the newly described T cell epitopes by determining their TCR Vβ expression profiles and MHC restriction. Overall, the novel RSV-derived CD4 and CD8 T cell epitopes identified in C57BL/6 mice will aid in future studies of RSV-specific T cell responses.