B cell and peptide based immunotherapy vaccine for Respiratory Syncytial Virus (RSV) infection (52.16)

Abstract

Abstract RSV is the most important pathogen for lower respiratory tract illness (LRI) in infants. There is no vaccine in use. As elicitation of antigen-specific CD8 T cell plays an important role in immune protection against many viruses, we sought to induce robust RSV-specific CD8 T cell immune responses. Ex vivo-activated B cells are an abundant source of antigen-presenting cells for immunotherapy. In the present study, we applied a novel approach using a combination of ex vivo-activated B cell prime and peptide boost to develop RSV vaccine, named as B-TriVax. TriVax uses a synthetic peptide representing a dominant RSV CD8 T cell epitope (M2 82-90), a toll-like receptor agonist (Poly-IC), and a costimulatory anti-CD40 antibody to generate large numbers of RSV-specific T cells. We primed BALB/c mice with M282-90-pulsed CD19+ B cells and boosted with TriVax at different time points after priming. We generated >20% M282-90-specific systemic CD8 T immune responses. Currently, we are investigating M282-90-specific CD8 T cell mediated vaccine efficacy in a RSV challenge model.