Mechanism of Action of Autoantibodies Penetrating Brain Tissue.
Autoantibodies that bind to cell surface proteins on glial cells or neuronal cells can induce complement-mediated cytotoxicity (CDC), which results in the formation of the membrane attack complex (MAC) (A). By contrast, antibody-dependent cell-mediated cytotoxicity (ADCC) is induced by Fc receptor-bearing effector cells that can lyse antibody-coated target cells (B). CDC and ADCC can result in cell death. Antibodies can interfere with the crosstalk of receptor signaling by acting as agonistic, antagonistic, or co-agonistic antibodies (C). Antibodies can cause receptor internalization following binding of their cell surface antigen, which leads to altered antigen density on the cell surface (D). Some brain-reactive antibodies will have no functional effect (E).