Protective natural autoantibodies and lupus pathogenesis

Excerpt

Antibodies produced by B lymphocytes provide key functions that help protect against pathogens while recent studies show there can also be roles in maintaining homeostasis. Substantial levels of spontaneously arising IgM antibodies recognize cross-reactive oxidation-associated epitopes, such as phosphorylcholine (PC) on apoptotic cells. One class of these natural antibodies can enhance efficiency of apoptotic clearance by innate immune cells, and also suppress proinflammatory responses. In vivo administration can block the development of the inflammatory autoimmune disease and enhance survival of lupus-prone mice. These inhibitory responses are linked to anti-inflammatory signaling with nuclear localization of MAPK phosphatase-1, a factor known to also mediate glucocorticoid suppression of immune responses. …