HLA-A2 Subtype Distribution Among Beijing Chinese And Its Effect On CTL Response In Vitro To P53 Protein Based Synthetic Peptide Vaccine

The distribution profile of HLA-A2 genotype and its 17 subtypes among the health Beijing Chinese has been analyzed by PCR-Sequence Specific Primer(PCR-SSP) technique. Among 200 samples, there are 55 cases of HLA-A2 genotype. Among 55 A2 types, 20 were subtyped to A201, 12 to A207, 5 to A210,4 to A203, 3 to A212, 2to A206 , A209 , A213 and A217, 1 to A204 , A208 and A211. The distribution is disperse and relatively unique. To evaluate whether the presentation of P53 based antigenic peptides selected on binding affinity could regularly induce A2 subtype restricted CTL response by the antigen presenting cell (APC), and whether different subtypes may exert profound influence on such CTL response, the mixed peptide loaded APCs and autologous lymphocytes culture systems from human cord blood were set up, which were restricted by HLA-A201 and HLA-A207, the two major subtypes of Beijing Chinese. The antigenic peptides used were P53 149-157, P53 264-272 and HBVc18-27 which were derived from P53 protein and HBV core antigen respectively, and known to bind A201 molecule by peptide binding assay. Dendritic cells (DCs), the APC, were grown in vitro with GM-CSF plus IL-4 and showed enhanced expression of class I and II molecules following subsequent addition of TNF-α. It was shown that A201 restricted CTL responses specific to all three antigenic peptides were readily induced from autologous PBMC by...