Hla-a*0201 T-Cell Epitopes in Severe Acute Respiratory Syndrome (Sars) Coronavirus Nucleocapsid and Spike Proteins

Abstract

The immunogenicity of HLA-A*0201-restricted cytotoxic T lymphocyte (CTL) peptide in severe acute respiratory syndrome coronavirus (SARS-CoV) nuclear capsid (N) and spike (S) proteins was determined by testing the proteins' ability to elicit a specific cellular immune response after immunization of HILA-A2.1 transgenic mice and in vitro vaccination of HLA- A2.1 positive human peripheral blood mononuclearcytes (PBMCs). First, we screened SARS N and S amino acid sequences for allele-specific motif matching those in human HLA-A2.1 MHC-1 molecules. From HILA peptide binding predictions (http://thr.cit.nih.gov/i-nolbio/hia- bitid/),. ten each potential N- and S-specific HLA-A2. 1- binding peptides were synthesized. The high affinity HLA-A2. 1 peptides were validated by T2- cell stabilization assays, with immunogenicity assays revealing peptides N 223-231, N227 -235, and N317-325 to be the first identified H LA, previous reports identified three HLA-A*0201-restricted CTL epi-A* 020 1- restricted CTL epitopes of SARS-CoVN protein. In addition epitopes of S protein (S978-986, S1203-1211, and S 1167-1175), here we found two novel peptides S787-795 and S 1042-1050 as S-specific CTL epitopes. Moreover, our identified N317-325 and S1042-1050 CTL epitopes could induce recall responses when IFN-gamma stimulation of blood CD8(+) T-cells revealed significant difference between normal healthy donors and SARS-recovered patients after those PBMCs were in vitro vaccinated with their cognate antigen. Our results would provide a new insight into the development of therapeutic vaccine in SARS