Complement receptors bind effector protein fragments that are produced in response to antigen-antibody complexes or damage-associated molecules.
[1] Complement receptor activation contributes to the regulation of inflammation, leukocyte extravasation, and phagocytosis; it also contributes to the adaptive immune response.
[4] White blood cells, particularly monocytes and macrophages, express complement receptors on their surface.
[1] Complement receptor (CR) 1, 3, and 4 function as opsonins which stimulate phagocytosis, whereas CR2 is expressed only on B cells as a co-receptor.
Red blood cells (RBCs) also express CR1, which enables RBCs to carry complement-bound antigen-antibody complexes to the liver and spleen for degradation.