Immunohistochemical Study on Changes of the T- and B-Cell Population in Uterus Draining Lymph Nodes of Mouse during Preqnancy

Abstract

The following experiment was performed to investigate changes of immune status in the uterus draining lymph nodes of pregnant ICR mice. The experimental animals were divided by duration of pregnancy as follows; Group I, virgin control; Group II, pregnancy 2nd day; Group III, pregnancy 5th day; Group IV, pregnancy 8th day; Group V, pregnancy 14th day; Group VI, pregnancy 19th day. The objective of this study was to focus on the changes in both B and T-cell systems. To note changes in the B-cell system, the nunber and distribution pattern of activated B cells were observed, the number of IgM and IgG positive plasma cells was counted" and the distribution pattern of surface IgM and IgG positive cells was observed. For changes in the T cell system, the distribution pattern of L3T4 positive and Lyt-2 positive cells was observed. Histochemical staining for activated B cells by means of membrane alkaline phosphatase activity (mAP) and immunohistochemical staining, such as avidin-biotin-peroxidase complex (ABC) and alkaline phosphatase-anti-alkaline phosphatase (APAAP) techniques for T cell and other B-cell systems were carried out. L3T4 positive cells in the deep cortex and IgM- and IgG-positive plasma cells in the medulla were significantly increased near the term. Lyt-2 positive cells were increased in the medullary cord or corticomedullary junction on the 5th day of pregnancy. The results obtained from the above experiment suggest that the conceptus evokes the immune responses locally as well as systemically and that immune responses against the conceptus involve changes in both the B cell and T cell systems, and especially the the T-cell system in early pregnancy and the B-cell system in late pregnancy may be operating.