HLA-A2 peptides are targets of HLA-A2-restricted cytotoxic T cells.

2003 AUG 6 - (NewsRx.com & NewsRx.net) -- Naturally occurring peptides associated with HLA-A2 in ovarian cancer cell lines were identified by mass spectrometry and determined to be targets of HLA-A2-restricted cytotoxic T cells.

According to a study from an international team of researchers, "Identifying naturally occurring peptides bound to HLA class I molecules recognized by HLA-restricted cytotoxic T lymphocytes (CTL) is both relevant and central to the development of effective immunotherapeutic strategies against cancer. Several cancer-related genes have been reported for ovarian cancer, but very few are known to be naturally processed T cell epitopes. In the present study we used mass spectrometry to identify 16 novel HLA-A2-bound peptides from HLA-A2+ ovarian cancer cell lines."

"All 16 peptides are derived from source proteins with diverse functions and marked homology to known proteins found in public databases," said Venkatesh Ramakrishna at Medarex, Inc., in the United States and collaborators in the United States, Sweden, and Italy. "Synthetic peptide analogues of identified sequences were found to stabilize HLA-A2.1, albeit with varying affinities. The peptides were found to be antigenic in that a primary CD8+ CTL response could be elicited from normal donor blood."

"The CTL generated were not only peptide specific, but failed to recognize targets pulsed with control peptides," stated Ramakrishna and associates. "In addition, recognition of shared HLA-A2-restricted epitopes by these CTL is ...