Quantitative differences in immune responses during the various stages of the estrous cycle in female BALB/c mice

In this study the authors wish to report that during the stages of the estrous cycle there is a significant modulation of the immune capacity of splenic lymphocytes from BALB/c female mice in response to T and B cell mitogens and to antigenic challenge with sheep erythrocytes. Of interest is the striking parallelism between immune reactivity, as discerned by us, and the previously reported biphasic changes in pregnenolone levels during the estrous cycle.