The primary function of the immune system is to protect the organism from invading pathogens. In response to pathogen invasion, multiple signaling pathways are activated in immune cells, leading to diverse immune defense mechanisms. Chief among these pathways is the activation of MAPKs, which are crucial for transcriptional and nontranscriptional responses of the immune system. Here we describe protocols to study the roles of MAPKs in T lymphocytes, a cell type central for immune regulation. Specifically, we describe flow cytometry-based assays to analyze the roles of MAPKs in the development, homeostasis, proliferation, and apoptosis of murine T cells. We also describe methods to examine the activation of MAPKs in T cells.
