[Regulation mechanisms of the activity of T lymphocytes : applications to infective and tumoral pathology. II. -- BCG and immuno-stimulation (author's transl)].

The inhibition of activated T cells by products of the humoral immune response is almost abolished in mice previously infected by BCG. As a result, these mice develop very high levels of DTH in response to doses of SRBC which cause complete suppression in normal mice. This systemic effect of BCG is dose, strain and time dependent and lasts for about three weeks. Its main effect is to inhibition of T cells by the products of the humoral. BCG infected mice develop increased levels of DTH associated with augmented antibody production, in contrast to the T cell potentiating effects of CY, which depend on a diminished production of antibodies. Since BCG and CY act in different ways, their effects are additive. Very remarkable levels of DTH are achieved when they are used in combination, in normal mice. These two agents together can also restore cell mediated immunity completely, but a further antigenic stimulus is needed to reestablish DTH in mice blocked by an humoral immune response or by a long period of continuous exposure to antigen. Some clinical T cell depressions are discussed in view of the humoral suppression, and the possible use of BCG to restore some functions of the T cell activity.