title: T-cells and B-cells in systemic sclerosis.
abstract: Systemic sclerosis (SSc) is characterized by activation of fibroblasts with extensive deposition of collagen, by small vessel vasculopathy with fibrointimal proliferation, and activation of the immune system, with hyper-γ- globulinaemia and autoantibodies. Twin studies have shown that genetic factors play a minor role in SSc development. Serum autoantibodies and skin lymphocytic infiltrates and small vessel damage occur very early before the appearance of skin fibrosis. T cells can cause fibrosis and vasculopathy through cell-cell contact and cytokines. They produce TH2 cytokines (IL-4, IL13) and TH17 cytokines (IL-17), which are profibrotic. TH2 cells in experimental models also induce pulmonary arterial hypertension. Genetically engineered TGFβ expression in pig arteries causes fibrointimal proliferation. T cells in skin lesions exhibit oligoclonality that persists over time, which indicates an antigen-driven T cell activation, but the antigen(s) responsible are not known. There are known environmental factors that can elicit an immune response and cause a SSc-like disease. T cells also provide help for B cells. B cells can contribute to fibrosis and vasculopathy through cytokines and autoantibodies. Autoantibodies can activate endothelial cells and fibroblasts to a profibrotic phenotype. Finally, treatments directed against T cells and B cells show promising effects in SSc.
authors.forename: Lazaros
authors.initials: L
authors.lastname: I Sakkas
authors.affiliation: Department of Rheumatology,Thessaly University General Hospital, Biopolis, Larissa 41 110, Greece.
authors.forename: Chris
authors.initials: C
authors.lastname: D Platsoucas