Effects of Chemicals on the Immune Response

Abstract

We have tested the effects of various environmental chemicals on proliferation of murine antigen-primed lymphocytes and their secretion of cytokines. Lymph node (LN) cells from mice immunized with bovine αsl -casein were incubated with this antigen in the presence of β-benzene hexachloride (β-BHC), p,p′-dichlorodiphenyldichloroethylene (p,p,p′-DDE), p-nitrophenyl 2, 4, 6-trichlorophenyl ether (CNP), D-α-aminobenzylpenicillin (Amp), and o-acetylcitric acid tributyl ester (ATBC), and tested for proliferation and secretion of interleukin (IL-) 2, IL-4, IL-10 and interferon γ. The results of the proliferation assays indicated that more than 20 ppm of CNP and DDE strongly inhibited the proliferation of LN T cells. All of the chemicals tested affected cytokine secretion by LN cells in response to antigen. The effects of these chemicals on cytokine secretion varied depending upon the cytokine examined and were independent of the inhibitory effect on cell proliferation. These results suggest that costimulation of T lymphocytes with certain environmental chemicals can modulate the antigen-specific cytokine responses of these cells, even at concentrations which are considered to have no toxicity and no inhibitory effect on the proliferative response of T cells.