Clonal analysis of restriction antigens for human TNP-specific cytotoxic T lymphocytes

Previous studies of populations of human TNP-specific cytotoxic T lymphocytes have shown a preference for HLA-matched, TNP-modified targets. However, substantial killing of modified targets mismatched for serologically defined HLA antigens is also observed. The present report concerns oligoclonal and monoclonal populations of TNP-specific cytotoxic lymphocytes from a single donor whose lymphocytes were primed in vitro to TNP-modified autologous lymphocytes and frozen in aliquots. Conditions for the expansion of precursors of cytotoxic cells to sufficient numbers for assay are described. Expansion required IL 2-containing supernatants and stimulator or feeder lymphocytes in great excess; PHA, present in the IL 2-containing supernatants, was not required. TNP modification of the stimulators in secondary cultures was not required but appeared to enhance activity. Oligoclonal populations showed marked preference for TNP-modified targets sharing any of 3 of the 4 HLA-A and -B antigens of the donor (Aw24, B8, Bw44) when compared with targets sharing only the 4th antigen (A1) or no antigens. Monoclonal TNP-specific populations showed marked preference for certain TNP-modified targets when tested against a panel, but the pattern often did not correspond with the serologically defined HLA-A and -B antigens. The data suggest that most or all TNP-specific cytotoxic clones are restricted in their killing patterns by determinants associated closely with but not necessarily identical to the serologically defined HLA-A and -B antigens.