Autoimmunity as a target for chimeric immune receptor therapy: A new vision to therapeutic potential.

Chimeric immune receptors (CIRs) are functionally pleiotropic because they are artificially expressed on diverse cell types, which gives specificity to their function to anergize, kill, or protect cognate target cells. CIRs consist of chimeric antigen receptors (CARs) and B-cell antibody receptor (BAR) or chimeric autoantibody receptors (CAARs). Approval of CAR-T cell therapy by the Food and Drug Administration (FDA) has encouraged investigators to search for autoimmune therapies that are CIR-based. Both T effector cells, particularly CD8+, and T CD4+ regulatory cells (Tregs) can be engineered through CIR expression. Recently, natural killer cells have been included to increase efficiency. Unwanted antibody producer B cells are effectively prevented by CAAR-T cells, B-cell antibody receptor (BAR)-T CD8+, and BAR-Treg, which represents an advantage in antibody-mediated diseases such as pemphigus vulgaris (PV) and hemophilia A. Although CAAR and BAR-T cells may have curative benefits for autoantibody-mediated immune diseases, verification of long-term efficacy and safety are a priority before clinical use. Effective CIR-T cell therapy largely depends on the reliability and stability of the receptor. Based on CIR functionality, factors that explicitly determine effectiveness of the treatment should be considered. These factors include antigen/autoantibody specificity, single chain variable fragment (scFv) affinity, and autoantibody masking. Herein, we review the current evidence of CIR therapy with a focus on their therapeutic potential for autoimmune diseases and their challenges.