Tissue-specific chimeric antigen receptor modified regulatory T cells for the therapy of hepatic inflammation

Autoimmune hepatitis (AIH) is a chronic inflammatory autoimmune disease of the liver. It involves a T-cell mediated autoimmune response against liver autoantigens, which leads to a loss of tolerance. AIH requires Lifelong immunosuppressive therapy, but this does not lead to a cure for AIH. For this reason, new therapeutic options are needed. One therapeutic approach is cell therapy with regulatory T cells (Treg). The aim of this cell therapy is the restoration of immunotolerance between regulatory and effector T cells. The genetic modification of Tregs with chimeric antigen receptors (CAR) can induce immunological tolerance specifically in inflamed tissue and thus serve as a possible therapy against immune mediated diseases. The CARs contain a tissue-specific single chain fragment (scFv), which ensures enrichment in inflamed liver tissue. To generate liver-specific CAR Tregs, highly specific scFvs were isolated by phage display. These scFvs were tested for specific binding of murine as well as human protein. Different second generation CAR constructs were engineered with these scFvs, which contain two intracellular signaling domains linked to a transmembrane domain. Downstream activation is triggered by specific binding of the scFvs to the target protein. The functionality of the CARs is tested in an NFAT-GFP reporter T cell line. This assay showed that the CARs specifically recognize the antigen without any autoreactivity. As proof of concept studies, the CAR Tregs were tested in disease relevant mouse models of AIH with a focus on stability, migration and effectiveness. In conclusion liver-specific Tregs are a promising therapeutic option for AIH.

Publication History

Article published online:
23 January 2024