Abatacept alleviates severe autoimmune symptoms in a patient carrying a de novo variant in CTLA-4

Inhibitory immune receptors presented on regulatory T (Treg) cells provide a critical balance in immune modulation by interacting with ligands expressed in antigen-presenting cells. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) on Treg cells suppresses immune reactions by interacting with CD80 and CD86, which are displayed by antigen-presenting cells, making it a useful target for immune modulation. Haploinsufficiency of CTLA-4 in human or knockout of the gene in mouse leads to immune dysregulation.