Lymphocyte subsets and mitogen induced proliferation in adjuvant arthritis. Part I. Migration and function of the peripheral T lymphocytes.

Adjuvant arthritis (AA) was used as an animal model of rheumatoid arthritis in this study. Seventy 10-week-old inbred female rats of both Long-Evans rats (LE, high responder of adjuvant arthritis) and Sprague-Dawley rats (SD, low responder of adjuvant arthritis) were inoculated with adjuvant. Using monoclonal antibodies, we demonstrated that redistribution, migration, or an imbalance of T lymphocytes rather than the change of total T cells are involved in the pathogenesis of AA. After the adjuvant injection, the lymphocytic proliferative responses of LE and SD rats to phytohemagglutin (PHA) had no significant difference, whereas the response of LE rats to concanavalin A (ConA) was significantly lower than that of SD rats. In addition, a highly significant positive correlation was found between the absolute numbers of helper T cells and the lymphocytic proliferative response to PHA, and between absolute numbers of suppressor T cells and the lymphocytic proliferative response to Con A. We postulated high responder strain LE would have a defect in suppressor T lymphocytes leading to severe arthritis, while in low responder strain SD, adjuvant-activated suppressor T lymphocytes might reduce the severity of arthritis.