Objective: To study the relationship between antigen presentation ability of spleen macrophage and maternal Th2>Th1 immune bias in Balb/c mice during late pregnancy.
Methods: Balb/c mice during late gestation were adopted in our study, and mice of same species in estrus were used as control. With antigen stimulation, the spleen macrophages of Balb/c mice were pulsed as antigen presentation cells (APC). T cells sensitized previously by pulsed macrophage (1 degree APC) were cultured in mixture with macrophage pulsed by same antigen (2 degrees APC). An antigen special lymphocyte transformation test in vitro was used to evaluate the antigen presentation ability of spleen macrophage from mice of late gestation, and a flow cytometry method was used to measured the ration of CD4, CD8, IL-10 and IFN-gamma positive cell in T cells which had being induced to proliferate.
Results: When spleen macrophage from mice during late gestation was used as 1 degree APC, the proliferation of sensitized T cell induced by macrophage from late pregnancy mice used as 2 degree APC was no more intense than that from estrous mice (P > 0.05). When spleen macrophage from mice in oestrus was used as 1 degree APC, the proliferation of sensitized T cell induced by macrophage from late pregnancy mice as 2 degrees APC was lower intense than that from estrous mice (P < 0.05). The type of 1 degree APC did not affect the ratio of IL-10 positive T cell, and macrophage from late pregnancy mice could induce more IL-10 positive T cell than that from estrous mice when they were used as 2 degrees APC (P < 0.05). The type of 1 degree or 2 degrees APC did not affect the ratio of IFN-gamma positive T cell.
Conclusion: The spleen macrophage from mice during late gestation is not an effective APC, but can induce maternal Th2 type of immune and maintain the Th1 type immune at a lower stage during pregnancy, which means it may has some important role in pregnancy.