INFLUENCE OF DIFFERENT B-COMPLEX RECOMBINANTS ON THE OUTCOME OF ROUS SARCOMAS IN CHICKENS

Seven major histocompatibility (B) complex recombinants were evaluated for anti-Rous sarcoma response. In experiment 1, the B(R5)(F21-G19) r ecombinant haplotype both homozygous and in heterozygous combinations with B19 and B21 haplotypes were compared to B19/B19 and B21/B21 chick ens to determine the relative influence of the B(F) versus B(G) chromo somal segments on regression of Rous sarcoma virus-induced tumours. In experiment 2, six recombinant haplotypes B(R1)(F24-G23), B(R2)(F2-G23 ), B(R3)(F2-G23), B(R4)(F2-G23), B(R6)(F21-G23) and B(R8)(F2-G2a,23) p resent in chickens heterozygous for normal haplotypes B19, B23 or B26 were compared for anti-sarcoma response. A total of 1328 chickens were blood typed for B alloantigens at 17 days of age, inoculated in the w ingweb with Rous sarcoma virus at 6 weeks and monitored for anti-tumou r immune response over a 10-week period. Genotypes which shared the sa me B(F) haplotype, but differed in their B(G) regions, had similar ant i-tumour responses, implicating the B(F) but not the B(G) region in tu mour regression. Chickens carrying B(F2) or B(F21) had a strong anti-t umour response, while B(F24) conferred a weaker response, regardless o f the accompanying normal haplotype.