ABSTRACT
This chapter summarizes investigations of a potential specific biologic suppressive mechanism for arthritis, collagen-specific T suppressor cells, and the biologic molecules these T cells elaborate. Summarized are the initial studies from this laboratory that showed mice chronically suppressed for collagen-induced arthritis contained specific T suppressor cell populations in their lymphoid tissues. Cytokines with immunoregulating activity have been observed from both clonal and polyclonal populations of cells. Although antigen-specific cytokines have been noted to suppress antibody synthesis, other nonspecific suppressor factors downregulate inflammation through the inhibition of production of interleukin-2 (IL-2), and still others such as lymphocyte-derived chemotactic factor, fibroblast inhibitory factor, and fibroblast activating factor, modulate connective tissue cell (fibroblast) function. In 1984, it was reported that 100 molecules were known that could mediate some aspect of the inflammatory process, and about 50 of those molecules were cytokines. Impaired IL-2 production and response have been observed in several animal models of autoimmune rheumatoid disease.
