Abstract
Apoptotic-cell clearance is dependent on several macrophage surface molecules, including CD14. Phosphatidylserine (PS) becomes externalised
during apoptosis and participates in the clearance process through its
ability to bind to a novel receptor, PS-R. CD14 has the proven ability
to bind phospholipids and may function as an alternative receptor for
the externallsed PS of apoptotic cells. Here we demonstrate that CD14
does not function preferentially as a PS receptor in apoptotic-cell
clearance. Compared with phosphatidylcholine and
phosphatidylethanolamine, PS was the least active phospholipid binding
to human monocyte-derived macrophages and showed no specificity for
soluble or membrane-anchored CD14. Significantly, PS-containing
liposomes a e to inhibit CD14-dependent uptake of apoptotic cells by
macrophages. PS exposure was, however, found to be insufficient for
either CD14-dependent or CD14-independent apoptotic-cell uptake by
phagocytes. The additional features that enable apoptotic-cell
clearance are derived from mechanisms that can be divorced temporally
from those responsible for the morphological features of apoptosis.
Original language | English |
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Pages (from-to) | 371-382 |
Number of pages | 12 |
Journal | Cell Death and Differentiation |
Volume | 10 |
Issue number | 3 |
DOIs | |
Publication status | Published - Mar 2003 |
Keywords
- monocytes/macrophages
- CD14
- apoptosis
- inflammation
- phagocytosis
- phosphaticlylserine