Mapping of CD8 T cell epitopes in human respiratory syncytial virus L Protein

Abstract

Objectives: Since it has been reported that in humans there is a relationship between human respiratory syncytial virus (hRSV)-specific cytotoxic T lymphocytes and symptom reduction, and that the polymerase (structural L protein) is highly conserved among different strains, this work aimed to identify the CD8 T cell epitopes H-2d restricted within the L sequence for immunization purposes. Methods: We screened the hRSV strain A2 L protein sequence using two independent algorithms, SYFPEITHI and PRED/ BALB/c, to predict CD8 T cell epitopes. The selected peptides were synthesized and used to immunize BALB/c mice for the evaluation of T cell response. The production of IFN-γ from splenocytes of hRSV-infected animals stimulated by these peptides was assayed by ELISPOT. Results: Nine peptides showing the best binding scores to the BALB/c MHC-I molecules (H-2Kd, Ld and Dd) were selected. Sequence homology analysis showed that these sequences are conserved among different hRSV strains. Two of these peptides induced significant IFN-γ production by ex vivo-stimulated T cells. Conclusions: Our results indicate that the hRSV L protein contains H-2d-restricted epitopes. © 2014 S. Karger AG, Basel.