2003 Volume 13 Issue 1 Pages 53-57
T cells specific for minor histocompatibility (H) antigens play a crucial role in immune responses in recipients following HLA-identical stem cell transplantation. Minor H antigen-specific cytotoxic T cell clones have been generated by random cloning followed by extensive characterizations for HLA restriction; thus it was difficult to expect to obtain T cell clones restricted by HLA allele of interest efficiently. Here we report a new approach that permits both direct visualization of T cell response to minor H antigens and cloning of T cells specific for minor H antigens presented by HLA alleles of interest. Panels of Epstein-Barr virus-transformed B lymphoblastoid cell lines (LCL) transduced with each of recipient's HLA alleles were used as stimulators in an enzyme-linked immunospot assay to identify restricting HLA alleles and LCL that possess minor H antigens detectable by T cell fractions in T cell lines generated from stem cell recipients. This method allowed us to select appropriate stimulators for positive selection of T cells specific for minor H antigens presented by HLA of interest using IFN-γcatch method. We have generated four cytotoxic T cell clones restricted by HLA-A24 which is the most common allele in Japanese (~60%) by this HLA-targeted cloning method. This new method could potentially applied to isolate T cell clones that recognize any antigens in the context of specific HLA alleles of interest.
