Objective: To study effect of blockade of costimulatory signal CD(80), CD(86) at the early stage of gestation on the maternal peripheral immuno-tolerance status to paternal antigen and pregnant outcome of murine abortion-prone model.
Methods: The experiments were performed in two groups, using CBA/J x BALB/c matings as the normal pregnancy model and CBA/J x DBA/2 matings as the abortion-prone model. The pregnant CBA/J mice which had mated with DBA/2 or BALB/c male mice respectively were injected intraperitoneally with purified rat isotype IgG or purified rat anti-mouse CD(80), CD(86) mAb at day 4 of gestation (time of implantation). The proliferation response of maternal splenic immuno-competent cells to paternal splenic cells as stimulator was analyzed by one way mixed lymphocyte reaction, and IL-2 production was assayed by ELISA to evaluate the immuno-tolerance of maternal peripheral immuno-competent cells to paternal antigen at day 9 of gestation. The embryo resorption rate was counted at day 14 of gestation.
Results: In the CBA/J x DBA/2 matings, anti-CD(80), CD(86) mAb administered at day 4 of gestation reduced significantly the embryo resorption rate, and induced a significantly lower proliferation response and IL-2 production by maternal splenic immuno-competent cells to paternal antigen compared with rat isotype IgG.
Conclusions: In vivo blockade of costimulatory signal at day 4 of gestation can induce the immuno-tolerance of maternal peripheral immuno-competent cells to paternal antigen, thus leading the embryo resorption rate of the abortion-prone model to that of normal pregnancy model.