for opsonins (C3b and C4b). Also many of the nonimmunological activators have
receptors for these opsonins. Opsonin fragments bind to their receptors and act to
facilitate adherence and phagocytosis of the target cell.
The function of the chemotactic factor (C5a) is to induce and direct the migration
and accumulation of phagocytic cells at the site of the immune reaction.
End of Lesson 2