Differential Response of B Cells to an Immunogen, a Mitogen and a Chemical Carcinogen in a Mouse Model System

BACKGROUND: B cells are specific antibody generating cells which respond to foreign intruders in the circulation. The purpose of this study was to compare the relative immunogenic potentials of three well established agent types viz. an immunogen, a mitogen and a carcinogen, by following B cell responses to their presence in a mouse model system. METHODS: Mice were treated with tetanus toxoid (immunogen), poke weed mitogen (typical mitogen), and benzo-α-pyrene (carcinogen) and generated B cell populations were determined in isolated splenic lymphocytes (splenocytes) by flow cytometry using specific anti-B cell marker antibodies. Flow cytometric estimation of LDL receptor (LDLR) expression, along with associated B cell markers, was also conducted. Kit based estimation of serum IgG, western blotting for LDLR estimation on total splenocytes and spectrometry for cholesterol and serum protein estimation were further undertaken. Student’s T-tests and one way ANOVA followed by the Bonferroni method were employed for statistical analysis. RESULTS: The mitogen was found to better stimulate B cell marker expression than the immunogen, although the latter was more effective at inducing antibody production. The chemical carcinogen benzo-α-pyrene at low concentration acted potentially like a mitogen but almost zero immunity was apparent at a carcinogenic dose, with a low profile for LDLR expression and intracellular cholesterol. CONCLUSION: The findings in our study demonstrate an impact of concentration of BaP on generation of humoral immunity. Probably by immunosuppression through restriction of B-cell populations and associated antibodies, benzo-α-pyrene may exerts carcinogenicity. The level of cholesterol was found to be a pivotal target.