THALIDOMIDE SUPPRESSES T-CELL AND B-CELL RESPONSES TO MYELIN ANTIGEN IN EXPERIMENTAL ALLERGIC NEURITIS

The effects of thalidomide and, for reference, dexamethasone on T- and B-cell functions were assayed in vitro in Lewis rats with experimenta l allergic neuritis induced by active immunization with bovine periphe ral nerve myelin (BPM) and complete Freund's adjuvant. Thalidomide and dexamethasone at the concentration ranges 10(-5)-10(-7) g/ml and 4 x 10(-5)-4 x 10(-9) g/ml, respectively, both inhibited phytohemagglutini n (PHA)- and BPM-induced T-cell proliferation as well as levels of PHA - and BPM-reactive interferon (IFN)-gamma-secreting cells, reflecting the suppression of Th1-like cells. The effect of dexamethasone was mos t pronounced on PHA-induced T-cell proliferation and IFN-gamma secreti on, whereas the effect of thalidomide was most pronounced on BPM-induc ed T-cell proliferation and IFN-gamma secretion. Thalidomide reduced t he B-cell responses to both BPM and Mycobacterium tuberculosis purifie d protein derivative, but to a lesser extent than dexamethasone. The i n vitro design described could be useful to evaluate compounds with pu tative immunomodulatory activities. The inhibitory effects of thalidom ide on autoantigen-induced Th1-cell functions may warrant the use of t his substance in T-cell-mediated autoimmune diseases.