CD4 and Sepsis: Sepsis significantly weakened the proliferation and IFN-γ secretion but enhanced the apoptotic level and IL-4 secretion of CD4+CD25− T cells of WT mice and Gulo−/− mice; however, treatment with 200 mg/Kg parenteral Vit C for two times after CLP significantly took a turn for the better and acted on upregulating the proliferative response and IFN-γ secretion as well as downregulating the apoptotic rate and IL-4 secretion.