T-cells and B-cells in systemic sclerosis

Area of Science:

• Immunology
• Rheumatology
• Fibrosis Research

Background:

• Systemic sclerosis (SSc) is a fibrotic disease marked by fibroblast activation, collagen deposition, small vessel vasculopathy, and immune system dysregulation.
• Genetic factors play a minor role, with environmental triggers suspected in SSc pathogenesis.
• Early SSc manifestations include autoantibodies, skin lymphocytic infiltrates, and small vessel damage preceding significant fibrosis.

Purpose of the Study:

• To elucidate the roles of T cells and B cells in the pathogenesis of Systemic Sclerosis.
• To explore the mechanisms by which immune cells contribute to fibrosis and vasculopathy in SSc.
• To evaluate the potential of immune-targeted therapies for SSc.

Main Methods:

• Analysis of T cell populations and cytokine profiles (TH2, TH17) in SSc lesions.
• Investigation of B cell contributions, including autoantibody production and cytokine signaling.
• Review of experimental models demonstrating T cell-mediated fibrosis and vasculopathy.
• Examination of the effects of TGFβ and environmental factors on SSc-like pathology.

Main Results:

• T cells, via cytokines like IL-4, IL-13, and IL-17, promote fibrosis and vasculopathy.
• Persistent oligoclonality in skin T cells suggests antigen-driven activation, though specific antigens remain unidentified.
• B cells contribute to SSc through autoantibodies and cytokines, activating endothelial cells and fibroblasts toward a profibrotic phenotype.
• Experimental models show T cell-induced fibrosis and vasculopathy, and TGFβ can induce fibrointimal proliferation.

Conclusions:

• T cells and B cells are key drivers of fibrosis and vasculopathy in Systemic Sclerosis.
• Immune cell activation, autoantibodies, and cytokine signaling are central to SSc pathogenesis.
• Therapies targeting T cells and B cells demonstrate promising potential for treating SSc.