Primary Immune Response in Swiss Mice Injected at Birth with a Single Dose of 7,12-Dymethylbenz [α] anthracene

Abstract

The primary immune response of 7,12-dimethylbenz[α] anthracene (DMBA) newborn treated outbred Swiss mice and untreated control animals of the same strain was determined at 10, 20, 30, 50, 75, 100, 150 and 200 days of age, according to the agar plaque technique of Jerne et al. The number of spleen antibody plaque forming cells (APFC) as well as the number of nucleated spleen cells was measured at time of sacrifice. The tumors observed in the treated groups were subcutaneous sarcomas and fibrosarcomas at the site of injection, and malignant lymphomas usually of the poor differentiated-cell type, either limited to the thymus or with extrathymic diffusion; in some instances animals with both subcutaneous tumors and malignant lymphomas were found. The number of APFC per spleen was constantly and markedly lower in the DMBA treated animals than in the control animals. Among the tumor bearing animals minimum numbers of APFC were recorded for the malignant lymphomas. According to the data of the present study and of previously reported observations, the possible relationship between immunodepression after DMBA treatment at birth and tumor development following the carcinogen injection is discussed.