Systemic Infection of Mice with Listeria monocytogenes to Characterize Host Immune Responses

Listeria monocytogenes is a Gram-positive facultative intracellular bacterium that is widely used to characterize bacterial pathogenesis and host immunity. Here, we describe a set of basic methods and techniques to infect mice with L . monocytogenes , measure bacterial load in tissues, and analyze immune cell subsets responding to infection in the spleen and liver. In addition, a specialized method for immune cell depletion is incorporated within the overall protocol, along with suggestions at various points in the protocol for minimizing experimental variability in mouse infection studies using L . monocytogenes . Finally, we highlight a number of experimental strategies for which L . monocytogenes has facilitated research into host immune responses and bacterial pathogenesis.