Increases in the numbers of immunoglobulin-secreting cells in lymph nodes responding to sperm and other stimuli: possible relationship to immunosuppression.

It has been reported that, in early pregnancy in mice, there is an increase in the number of immunoglobulin-secreting cells in the lymph nodes which drain the uterus. This paper describes the results of further investigations provoked by interest in these early changes. Increases in the numbers of immunoglobulin-secreting cells were observed in syngeneically, but scarcely or not at all in allogeneically, mated mice. Increases were not observed in surgically sterilized female mice inseminated by normal males. However, subcutaneous injection of sperm provoked massive increases in the numbers of immunoglobulin-secreting cells in the lymph nodes draining the injection site. The changes were compared with those provoked by the injection of spleen cells and LPS. The results are discussed in relation to the nature of the interactions provoking the increases in the number of immunoglobulin-secreting cells and their possible relationship to immunosuppression, and the relative immunological unresponsiveness which the female shows to the challenge of inseminated sperm.