GENETIC CONTROL OF THE IMMUNE RESPONSE : THE EFFECT OF GRAFT-VERSUS-HOST REACTION ON THE ANTIBODY RESPONSE TO POLY-L(TYR,GLU)-POLY-D,L-ALA--POLY-L-LYS IN NONRESPONDER MICE

The transfer of parental (H-2(k/k)) nonresponder lymphoid cells into heterozygous (H-2(k/q)) nonresponder recipients at the time of primary challenge with aqueous poly-L(Tyr,Glu)-poly-D,L-Ala-poly-L-Lys [(T,G)-A--L] elicited the production of both IgM and IgG anti-(T,G)-A--L antibody. Normally, the production of IgG anti-(T,G)-A--L antibody is restricted to strains possessing the responder Ir-1 allele. The timing and intensity of the graft-versus-host (GVH) reaction required for this effect were found to be critical. Injection of H-2(k/k) cells into H-2(k/q) recipients 1 wk before antigen challenge did not elicit IgG anti-(T,G)-A--L antibody production, and markedly suppressed IgM anti-(T,G)-A--L antibody production. The transfer of alloimmune (H-2(q)-primed) H-2(k/k) cells at the time of antigen challenge was also associated with no IgG and little IgM anti-(T,G)-A--L antibody production. These data are consistent with the model that nonresponder thymus-derived lymphocytes (T cells) activated in a GVH reaction can substitute for (T,G)-A--L-reactive T cells to induce a shift from IgM to IgG anti-(T,G)-A--L antibody production.