Ontogeny of B lymphocyte function. VI. Ontogeny of thymus cell capacity to facilitate the functional maturation of B lymphocytes.

The differentiation of the B cell population from fetal mice to produce a normal, adult-like, heterogeneous reponse, with respect to antibody affinity, has been shown to require (or to be facilitated by) thymus cells. The maturation of the thymus cell population to be capable of facilitating this differentiation of the B cell population was studied. It was found that the thymus cell population acquires the capacity fo facilitate (or induce) this maturation of the B cell population between seven and ten days after birth. Thus, the normal maturation of the B cell population to give a response which is heterogeneous with respect to affinity, appears to be controlled by the maturation of thymus function.