Primed lymphocyte testing in pigs: conditions for the generation of primed cells and their response characteristics.

Pig peripheral blood lymphocytes, typed for LD antigens by negative reactions to homozygous cells in primary MLRs and for SD antigens by complement-mediated lymphocytotoxicity, were sensitised in vitro against X-irradiated lymphocytes. These "primed" cells were rechallenged with lymphocytes possessing a range of LD and SD phenotypes and were found to respond by rapid proliferation specifically to LD antigens of the type expressed by the original stimulating cell, but not to SD antigens. Third party LD antigens, not expressed by the original sensitising cell, or by the responder, caused a significant proliferation, but primed cells could be rendered operationally monospecific by reducing the number of responding cells until the third party reaction became negligible. Conditions for the generation and testing of these primed pig cells are described here.