Scavenger receptors as regulators of natural antibody responses and B cell activation in autoimmunity

Innate immune activation is crucial in defense against invading pathogens, including recognition by pattern recognition receptors, such as scavenger receptors. The scavenger receptor family was originally defined by their ability to bind oxidized LDL and thus the majority of research on this set of receptors has been done in association with cardiovascular disease. However, these receptors also bind an array of other modified self and foreign ligands and have for this reason the ability to regulate the immune response, including B cell activation. In this respect, increasing evidence suggests that these receptors are involved in autoimmunity and might provide a link between autoimmune disease and atherosclerosis. In this review, we will summarize how scavenger receptors can regulate activation of B cells both through their expression on this cell type but also by functions mediated by expression on cells interacting with B cells. Recent evidence of scavenger receptor function reveals how the transition from natural and polyreactive antibody responses towards potentially pathogenic B cell activation occurs. This translates to a new role for scavenger receptors in atherosclerosis and autoimmune disease, such as systemic lupus erythematosus.