Supplemental zinc restores antibody formation in cultures of aged spleen cells.

The in vitro production of antibody to T-dependent antigens is depressed as a function of age. The addition of supplemental zinc to cultures of cells from young adult, middle-aged, and immunodepressed-aged mice enhances antibody production. The responses of young mice are enhanced 30 to 40%, but the responses in cultures from aged mice are increased 5- to 12-fold and the maximum response achieved is often equivalent to that of young, fully competent mice. The addition of zinc at varying times during the culture period suggests that zinc affects early events in the activation of antibody-forming cells.