C1q binds phosphatidylserine and likely acts as a multiligand-bridging molecule in apoptotic cell recognition.

ABSTRACT: Efficient apoptotic cell clearance is critical for maintenance of tissue homeostasis, and to control the immune responses mediated by phagocytes. Little is known about the molecules that contribute "eat me" signals on the apoptotic cell surface. C1q, the recognition unit of the C1 complex of complement, also senses altered structures from self and is a major actor of immune tolerance. HeLa cells were rendered apoptotic by UV-B treatment and a variety of cellular and molecular approaches were used to investigate the nature of the target(s) recognized by C1q. Using surface plasmon resonance, C1q binding was shown to occur at early stages of apoptosis and to involve recognition of a cell membrane component. C1q binding and phosphatidylserine (PS) exposure, as measured by annexin V labeling, p

SUBMITTER: Paidassi H 

PROVIDER: S-EPMC2632962 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature