Human and murine CD3 deficiencies provide insight into the essential and re
dundant roles of CD3 proteins in T-cell development and immature T-cell fun
ction. Mature T-cell lines derived from a patient with CD3 gamma deficiency
suggest that CD3 gamma participates in the induction of interleukin-2 (IL-
2) and that the T-cell receptor (TCR)-CD3 complex is biochemically differen
t in T-helper and Tc cells when CD3 gamma is lacking.