OBJECTIVE: To investigate the alloimmunogenicity of liver specific antigen and its effects on allolymphocytes.
METHODS: Liver specific antigen isolated from inbred F344 rats was used as immunogen to immunize inbred Lew rats through different immunization pathways such as low-dose long-term hind footpad, high-dose portal vein and thymus immunization. Western blotting, DNA fragments gel electrophoresis, mixed lymphocyte culture (MLC) and mixed lymphocyte hepatocyte culture (MLHC) were employed to analyze the immune state after immunization.
RESULTS: At the time point of sampling, different degree of specific low immunoresponses appeared in all immunized groups as well as cyclophosphamide (CY) treated group. Compared with group Ⅰ, other groups expressed caspase-3 significantly as detected by using Western blotting. DNA fragment gel electrophoresis of splenocytes showed lymphocyte apoptosis. Compared with the group Ⅰ, MLC of the experimental groups showed no significant changes except that of the group Ⅴ, whereas MLHC decreased markedly (P<0.05).
CONCLUSIONS: Liver specific antigen not only has alloimmunogenicity to induce alloimmunoreaction but induce antigen specific low immunoresponses and antigen specific lymphocyte apoptosis by high-dose or low-dose long-term immunization. It may be an important transplantation antigen that may lead to a novel way to liver transplantation immunotolerance.