[34] Streptococcal cell wall-induced arthritis in rats

Intraperitoneal administration of sonicated cell walls prepared from group A streptococci induces an acute inflammation in the hind paws of inbred female Lewis rats. Mechanistic studies with this cell-wall model have shown that the chronic arthritis is a T-cell-dependent lesion. Thus, athymic inbred Lewis rats develop the acute inflammatory lesion when they are treated with cell walls. However, these athymic rats do not develop the chronic lesion unless they are treated with spleen cells derived from euthymic littermates. These observations indicate that the acute arthritis induced by cell walls is a T-cell-independent lesion and the chronic disease is T-cell dependent. Rheumatoid arthritis is a complicated immunologic disease, and the lesion induced in rats by streptococcal cell walls is, at best, merely a model of the human lesion. Although several similarities exist between the cell-wall model and the human disease, additional studies are required before it is concluded that this model is an exact counterpart of rheumatoid arthritis. Streptococci can induce infections of the throat, and it is possible that the organisms can induce other lesions. Therefore, care should be taken when growing and processing streptococci cells and cell walls.