Effect of dimethyl sulfoxide on humoral immune responses to acetylcholine receptors in the rat

The effects of dimethyl sulfoxide (DMSO) on the humoral immune responses to acetylcholine receptors (AChR) were studied in rats with experimental autoimmune myasthenia gravis. DMSO was administered during primary, ongoing, and secondary phases of the immune response to AChR. Anti-AChR antibody titers were measured to determine the effect of the treatment. DMSO had pronounced effects on the humoral immune response, which differed depending on the stage of the response and the strength of antigenic stimulation. When given during an ongoing immune response, DMSO suppressed anti-AChR antibody levels by an average of 53-76%. This effect was similar whether DMSO was given by oral, rectal, or intraperitoneal routes. DMSO treatment also suppressed the anti-AChR antibody response to a weak primary antigenic stimulus to a similar extent. In contrast, when administered during a secondary or a strong primary immunization, DMSO enhanced the anti-AChR antibody response 1.7- to 2.8-fold. These results show that DMSO may either enhance or suppress humoral immune responses. Further studies will be required to analyze the cellular mechanisms underlying the actions of DMSO.