摘要: While the effects of cytokines on T helper 1 (Th1)/Th2 differentiation are well documented, it is less clear why a dichotomy effector cytokine production would initiate from antigen-specific lymphocytes. Nevertheless, in defined experimental systems, interaction between T-cell receptor (TCR), peptide and major histocompatibility complex (MHC) can determine Th1/Th2 dominance. Here, Joseph Murray discusses how TCR affinity ligand density might interface with innate forces selection CD4+ functions.