Macrophage Surface Expression of Annexins I and II in the Phagocytosis of Apoptotic Lymphocytes

• DOI: 10.1091/mbc.e03-09-0670
• Publication Date: 2004-04-06T00:45:04Z
• Authors: Xiaoxuan Fan; Stephen Krahling; Douglas Smith; Patrick Williamson; Robert A. Schlegel
• Keywords: Jurkat cells; Annexin A5

When cells undergo apoptosis, or programmed cell death, they expose phosphatidylserine (PS) on their surface. Macrophages that efficiently phagocytose apoptotic also express PS surface, although at a lower level. The exposed both is required for phagocytosis, because uptake inhibited by masking either with annexin V, PS-binding protein. inhibition not additive, suggesting the molecules two participate in common process. We asked whether this dual requirement reflects bridging of target and macrophage bivalent, annexins. Monoclonal antibodies (mAbs) against annexins I II stained variety live phagocytes. Apoptotic Jurkat T lymphocytes human peripheral lymphocytes, but thymocytes, were anti-annexin II. Phagocytosis targets was mAbs to II, pretreatment macrophages same mAbs. Pretreatment thymocytes had no effect, whereas pretreating removing EGTA inhibitory. Annexin vectorial, bound macrophages, serve as ligand receptor promoting phagocytosis.