| Abstract: | PROBLEM: Murine pregnancy is characterized by transient thymic atrophy and splenomegaly. Although some reports on the thymus are available, little is known about the role of the spleen. In the present study, sequential changes in the spleen have been evaluated during murine syngeneic pregnancy. METHOD OF STUDY: Formation of germinal centers (GCs), immunoglobulin positive (Ig+) cells and interleukin (IL)-2, IL-4, and IL-6 were immunolocalized in the spleen during pregnancy and compared with a control group of virgin mice. RESULTS: Initiation of T-cell dependent B-cell response with the induction of peanut agglutinin (PNA+) GCs correlated with decrease in IL-2 and maintenance of IL-4 and IL-6 on day-1 pregnancy followed by an increase in Ig+ cells. CONCLUSION: The immune response observed in the syngeneically pregnant mother is not directed to paternal major histocompatibility complex antigens. Present studies demonstrate for the first time the role of the spleen in initiating a T-cell dependent B-cell response with a shift of systemic immune response from T helper 1 to T helper 2 type. |
