Failure of "thymus factor" to restore transplantation immunity in athymic mice.

Implantation of cell impermeable Millipore chambers containing thymuses from normal newborn donors into athymic mice does not confer on them the capability to reject allogeneic skin grafts. The same deficiency is manifested when skin grafted female nude mice are pregnant of foetuses with normal thymuses. These data are thus in sharp contrast to those previously reported for thymic factors reconstituting neonatally thymectomized mice.