Production of a glycosaminoglycan stimulatory factor by cloned human t lymphocytes activated in vitro

Abstract

Supernatants of mitogen‐activated mononuclear cells contain a factor which stimulates, up to fifteenfold, the synthesis of glycosaminoglycan (GAG) by cultured normal dermal fibroblasts. To demonstrate that the GAG stimulatory factor is a product of T lymphocytes, we cloned normal peripheral blood T lymphocytes that were activated in mixed lymphocyte culture. Selected alloreactive T cell clones were expanded in the presence of original stimulator cells and T cell growth factor. Only supernatants of the clones that were reactivated with irradiated stimulators (allogeneic peripheral blood lymphocytes of B cell lines) were capable of increasing, 3–7‐fold, the GAG synthesis by dermal fibroblasts. The production of GAG stimulatory activity by alloreactive T cells was restricted by HLA‐DR allorecognition. Alloactivated T cell clones produced more GAG stimulatory activity on a per cell basis than did concanavalin A‐activated mononuclear cells. These results show that cloned, activated T lymphocytes are capable of releasing soluble factors that modulate GAG synthesis by normal dermal fibroblasts.