CD4 and Sepsis: Can mature into Th1, Th2, or Th17 cell subsets depending on the type of cytokine stimulation from APC, CD20 interaction, etiologic pathogen and other factors. Th1 cells produce more pro-inflammatory cytokines, associated with pathogen eradication. Th2 cells produce more anti-inflammatory cytokines, leading to anergy and “immunoparalysis” in sepsis Adaptive immunity Express CD4, CD3, CD5, CD28, CD45, CD154