Functional and phenotypic analysis of T lymphocytes cloned from the skin of patients with systemic sclerosis

Activated T lymphocytes often accumulate in the lower dermis of patients with systemic sclerosis (scleroderma) and may play a role in the development of dermal fibrosis. We propagated and cloned these cells directly from skin biopsies in four of eight cases of early, untreated systemic sclerosis with diffuse scleroderma. The cloning frequency estimates were f = 0.20 and f = 0.48 for T cells derived from the skin of two patients versus f = 0.68 and f = 0.96 for autologous blood T lymphocytes. All but one of 24 skin-derived scleroderma clones were CD4+. Clonal analyses performed with CD4+ clones from patients and normal controls showed that all but one skin-derived clones synthesized either interferon-gamma (60%), glycosaminoglycan-stimulatory factor (26%) or both (9%) when induced in vitro by a mitogen, concanavalin A, but not by autologous dermal fibroblasts. In contrast, blood-derived clones had a different functional phenotype. All skin-derived clones produced tumour necrosis factor-alpha. Our results demonstrate that T lymphocytes obtained from the skin of patients with systemic sclerosis synthesized cytokines which could modulate functions of human dermal fibroblasts.