Infection with Listeria monocytogenes as a probe for placental immunological function.

This chapter will describe the use of infection with Listeria monocytogenes, a Gram-positive intracellular bacterium, to study immunological responses in the placenta. This bacterium is chosen because it has a predilection for replication in the placenta. As such, it is a significant pathogen for pregnant women, being a major cause of fetal mortality and morbidity if appropriate public health precautions are not observed. Furthermore, this bacterium has been a major tool for studying innate immune responses and their transition to an acquired one, characterized by a Th1-type response. Details are given for the culture and maintenance of bacteria stocks, infection of mice, and analysis of the resultant infection. Such studies have revealed a unique pattern of immune responses in the placenta that, through the methods described, should reveal the strategies that the placenta uses to eradicate pathogens while not rejecting allogenic fetuses.