Figure 7.

Model for pregnant immune system affected by P4/COR in vivo. Left panel; Regulation of immune condition by P4/COR in the humanized mouse model (NOG-hIL-4-Tg). P4 treatment maintains CD62L expression on T cells and contributes to T cell accumulation in the spleen. In contrast, COR does not maintain the CD62L expression, and the T cell activation and migration in the periphery cannot be suppressed. Right panel; Regulation of immune condition by P4/COR in human pregnancy. A high P4 environment in the placenta maintains non-reactive T cells but kills fetus-reactive T cells. The naïve T cells are stored in the peripheral lymphoid tissues such as the spleen and lymph node. However, after the delivery, P4 concentration drastically decreases, and the stored naïve T cells migrate into the periphery, protecting the mother from infectious disease.