Reverse vaccinology

A major drawback in vaccine development in animal health is the fact that antigenic peptides presented by MHC class I (in pigs SLA-I) have not been fully characterized, hampering the rational design of vaccines. Identification and characterization of B- and T-cell epitopes (also known as antigens) for a given pathogen has proved crucial for understanding the basic mechanisms of immunological protection and for the rational design of effective vaccines. Protective immunity is usually mediated by B lymphocytes, CD8+/CD4+ T lymphocytes or both. Recognition of epitopes by lymphocytes from different species and individuals is restricted by the major histocompatibility complex (MHC) molecules – named swine leukocyte antigen (SLA) in pigs- which is responsible for foreign antigen presentation. In the case of viral infections, classical SLA class I (SLA-I) molecules act as molecular cradles that present endogenous and foreign peptides or epitopes to cytotoxic CD8+T cells (CTL) at the cell surface of healthy and infected cells. Thus, they provide the immune system with a mechanism for interrogating the viral proteome from the outside of infected cells. Our team and in collaboration with other international groups have applied reverse vaccinology to identify cross-reacting MHC class I T-cell epitopes from two different Swine Influenza virus (SwIV) H1N1 lineages in pigs presented by SLA-1*0702.