Cellular and humoral immunity after allogeneic renal transplantation in the rat. V. Appearance of anti-idiotypic antibody and its relationship to cellular immunity after treatment with donor spleen cells and alloantibody.

Enhancement of LBN F1 renal allograft survival in Lewis (L) rats is achieved by injecting the recipient i.v. with donor antigen (LBN F1 spleen cells) 1 day before transplantation and antidonor antibody (L anti-BN alloantiserum) at the time of transplantation. Treatment with this combination of antigen and antibody also induces the recipient to make L anti-(L anti-BN) anti-idiotypic antibody that reaches peak titers within 10 days. The degree of graft enhancement achieved was increased greatly by delaying transplantation until the peak of the anti-idiotypic antibody response 10 days after treatment with antigen and antibody. Two in vitro assays for cellular immunity (51Cr release and microcytotoxicity) failed to demonstrate antidonor activity in spleen cells from recipients for which transplantation had been delayed 10 days. The close correlation of enhancement, absence of cellular immunity in vitro, and the kinetics of the anti-idiotypic antibody response suggest that anti-idiotypic antibody may prevent either sensitization and generation of effector T lymphocytes or the destructive potential of sensitized cells.