T and B Immunodepression during 7,12-Dimethylbenz(α) Anthracene (DMBA) Carcinogenesis in Mice

Abstract

Certain chemical carcinogens administered to animals either at birth or later in life induce a marked and long-lasting reduction of both humoral and cellular T-dependent immune responses (1–7). Both responses are thymus-dependent, requiring either cooperation (8) or direction action of T lymphocytes (9). Recent reports indicate the existence of antigens inducing humoral antibody formation independent of thymus cell action (10). The present experiment was undertaken to study a B lymphocyte immune response in DMBA-treated mice. For comparison, a T-dependent humoralresponse was also studied using the same model. Moreover, in view of the fact that changes in normal rate of cellular proliferation in lymphoid tissues could be an important phenomenon during the early phases of carcinogenesis (11), we concomitantly studied the rate of cellular proliferation in central and peripheral lymphoid tissues of mice treated with DMBA at birth.