Defective production of anti-inflammatory cytokine, TGF-β by T cell lines of patients with active multiple sclerosis

Activated T lymphocytes play an important role in the pathogenesis of multiple sclerosis (MS). These T cells secrete both pro- and anti- inflammatory cytokines. We have studied the production of these two kinds of cytokines by PBL of patients with MS and compared it with normal controls and other autoimmune diseases (OAD). PBL of 29 patients with MS, 14 patients with OAD, and 14 healthy normal controls were cultured for 5 wk. PBL of MS patients produced more pro-inflammatory cytokines, IL-2, IFN-γ and TNF/lymphotoxin, and less anti-inflammatory cytokine, TGF-β, during wk 2 to 4 in culture than PBL of normal controls. PBL of MS patients also produced more IL-2 and TNF/lymphotoxin than PBL of OAD patients. Decreased TGF-β production by lymphocytes of patients with MS correlated directly with disease activity. MS patients with active disease produced less TGF-β than MS patients with stable disease. The cells producing TGF-β were primarily CD8⁺ T cells and CD45RA⁺T cells. These findings emphasize the complexity of immune response in MS patients and suggest that the increased production of pro-inflammatory cytokines by lymphocytes of patients with MS, combined with the decreased production of TGF-β (anti-inflammatory cytokine), may play an important role in the mechanisms and manifestations of MS.