Col-Treg

Col-Treg is a personalized, antigen-specific T cell immunotherapy consisting of autologous collagen type II–specific regulatory T lymphocytes (Tr1-like Tregs) developed for the treatment of autoimmune diseases affecting collagen-rich tissues, particularly autoimmune uveitis and potentially rheumatoid arthritis. These ex vivo–expanded CD4+ regulatory T cells recognize collagen type II and exert potent bystander immunosuppressive effects via high interleukin-10 production, IL-13 secretion, and contact-independent suppression of effector T cells, while expressing activation and regulatory markers such as GITR, CD39, granzyme B and CTLA-4 and lacking constitutive high FoxP3/CD25 expression characteristic of thymic Tregs.[1][5][7] Preclinical studies demonstrated that adoptive transfer of Col-Treg clones in collagen-induced and collagen antibody–induced arthritis models reduces arthritis incidence and severity, decreases collagen type II–specific antibody titers (notably IgG2a), and protects joint structure, supporting its development by TxCell as a first-in-class, autologous collagen II–specific Treg cell therapy for severe, therapy-refractory autoimmune uveitis and other joint inflammatory diseases.[1][5][7]