RAT ERYTHROCYTES ELICIT ANTIBODY-FORMATION AGAINST RT1.A REGION-DETERMINED ANTIGENS IN ALLOGENEIC RECIPIENTS

Abstract

Highly purified erythrocytes of inbred LEW (RT11) rats (LEW-E) elicited antibody responses in inbred BN (RT1n) rats. I.v. infusion of 1 .times. 108 LEW-E elicited IgM hemagglutinins and after 1 further infusion of LEW-E IgG hemagglutinins were raised. These hemagglutinins were mainly directed to RT1.A region-determined classical transplantation antigens, but a weak response to non-RT1 minor histocompatibility antigens was obtained. In the reciprocal combination erythrocytes of BN and LEW.1N rats, which carry the RT1n haplotype on the LEW strain genetic background, infused into LEW rats yielded strong IgM hemagglutinin responses to RT1.A antigens only but failed to elicit IgG antibody. Infusion of LEW.1N rats with LEW-E elicited only weak IgM hemagglutinin responses. RT1.A antigens evidently are immunogenic for they elicit IgM alloantibody responses. IgG hemagglutinin responses to LEW-E may depend on the presence of minor histocompatibility antigens in conjunction with RT1.A antigens on LEW-E or alternatively on control by Ir-genes located outside the RT1 complex.