CD4 and infection: To more directly and rigorously interrogate the long-term consequences of sepsis on memory CD4 T cells, we used a protocol where an endogenous, Ag-specific memory CD4 T cell population was generated by infection with attenuated Listeria monocytogenes engineered to express the I-Ab-restricted peptide 2W1S (Lm-2W1S) 30 days before performing sham/CLP surgery (Figure 1A).