The Effect of Endogenous Ligands of the Aryl Hydrocarbon Receptor on Antibody Expression in a Human B-Cell Model

Small changes in antibody expression have broad impacts on human health and disease. An environmental toxicant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces profound immune suppression in animal models in an aryl hydrocarbon receptor (AhR)-mediated fashion. In a human Burkitt\u27s lymphoma cell line (CL-01), TCDD inhibited IgG secretion and differentially impacted Ig heavy chain expression. In addition to TCDD, the AhR has several endogenous, dietary, and bacterial ligands such as 6-formylindolo[3,2-b]carbazole (FICZ) and indole, which are present within the human body at varied concentrations (0.30 mM- 6.64 mM). Both FICZ (100 nM) and indole (100 µM) significantly reduced IgG secretion. Overall antibody secretion is less sensitive to endogenous ligands of the AhR than TCDD, which inhibits IgG secretion in the nM concentration range. However, antibody secretion is inhibited by FICZ, suggesting a biological role of the AhR in antibody expression