IMMUNOLOGIC CHARACTERIZATION OF MHC RECOMBINANT SWINE

Abstract

Two intra-MHC recombinant haplotypes have been examined to document the nature of the recombination and to generate MHC-specific alloantisera. Cells from progeny of recombinant pigs have been compared by mixed lymphocyte reaction, by complement-dependent cytotoxicity with standard alloantisera, and by sodium dodecyl sulfate polyacrylamide gel electrophoretic (SDS-PAGE) analysis of immune precipitates of radio-labeled extracts. The results demonstrate that both recombinant haplotypes, f and g, have inherited the SLA-A,B loci of the c haplotype and the SLA-D loci of the d haplotype, and that no differences between the two recombinant chromosomes are detectable. Class specific anti-SLA-A,B and anti-SLA-DR sera were produced in or against the g haplotype. In terms of cytotoxicity and SDS-PAGE these sera exhibited the expected reactivities, except that the high-titered anti-SLA-DR sera gave an unexpectedly high percentage of lysis of swine peripheral blood lymphocytes. That cells other than pig B cells were being lysed by the anti-SLA-DR sera was confirmed by analyses of subpopulations of peripheral blood lymphocytes. Approximately 50% of nylon nonadherent T cells were specifically lysed by allo-anti-Ia sera. Similar lysis of T cells was found with crossreactive mouse anti-Ia sera. Thus, unlike other species in which Ia antigens are expressed on T cells at low levels and are difficult to detect, the SLA-D region products are readily detectable on swine peripheral blood T lymphocytes.