| Abstract: | The present study investigates some of the immunogenetic bases for tolerance of anti-allo-delayed type hypersensitivity (DTH) responses as induced by pre-inoculating allogeneic cells via portal venous (p.v.) route. BALB/c mice were injected with totally allogeneic C57BL/6 or H-2 incompatible BALB.B spleen cells via p.v. route. These mice not only failed to exhibit anti-H-2b DTH responses, but also abrogated the potential to generate H-2b-specific DTH responses as induced by the subsequent immunization with H-2b spleen cells via subcutaneous (s.c.) route. The p.v. presensitization with allogeneic spleen cells differing at either class I or class II of major histocompatibility complex (MHC) resulted in the tolerance induction of DTH responses to the respective allogeneic class I or class II MHC antigens. Moreover, the p.v. administration of the class I-positive allogeneic cell fraction depleted of class II-positive component into recipients differing at both class I and class II was capable of inducing anti-class I DTH tolerance. These results indicate that anti-allo-class I or class II DTH tolerance can be induced independently and that the existence of class II antigens on p.v.-presensitized cells is not necessarily required for the tolerance induction of anti-allo-class I DTH response. |
