Evaluation of in vitro and in vivo activities of isoantibodies directed against idiotypes and recognition structures for transplantation antigens.

Anti-idiotype sera were prepared by injection of CBA anti-A/JAX serum with or without adjuvant into CBA mice. These sera were tested in allocluster inhibition and passive enhancement-facilitation. While the anti-idiotype sera inhibited allocluster formation, particularly when prepared with complete Freund's adjuvant, they had virtually no effect on enhancement of Sa I grafted in CBA mice except for a marginal prolongation of graft survival in one out of three experiments. Anti-RS serum was prepared by immunizing (CBA X A)F1 mice with CBA thymus or spleen cells. The sera were tested in local graft-versus-host inhibition and passive enhancement. F1 anti-CBA thymus serum inhibited the local graft-versus-host reaction but had no enhancing effect. F1 anti-CBA spleen serum was virtually ineffective in both tests although a slight tendency to graft-versus-host inhibition was noted. The relative contribution of anti-idiotype and/or anti-RS antibodies to transplantation reactions is discussed.