Phagocytosis-Associated Functions in Neonatal Monocyte-Derived Macrophages

Abstract

ABSTRACT: Using a Teflon culture system we analyzed different aspects of cell maturation and phagocytic activities in neonatal monocyte-derived macrophages. Morphological and cytochemical characteristics as well as the protein composition of neonatal macrophages were identical with those of adult controls; actin binding protein (265,000 Da), myosin (210,000), α-actinin (102,000) and actin (42,000) could be identified in cells from either source. All phagocytic functions were shown to be perfectly normal in neonatal macrophages when compared with adult cells: random migration, chemotactic response to zymosan-activated serum and formyl-methionyl-leucyl-phenylal-anin, ingestion, and killing of Staphylococcus aureus, phagocytosis-associated chemiluminescence, production of oxygen intermediates (superoxide anion, O-2; hydrogen-peroxide, H2O2). Phorbol myristate acetate-stimulated O-2 -generation by 1 X 105 macrophages was 11.8 ± 4.7 nmol/h for neonates, and 10.2 ± 3.9 for controls; production of H2O2 was 7.6 ± 3.5 nmol/h in neonatal macrophages and 6.4 ± 2.8 in adult controls. It is unlikely, then, that the increased susceptibility of human neonates to systemic bacterial infections can be related to an abnormality in the essential phagocyte functions of macrophages.

Author information

Correspondence to Christian P Speer.

Rights and permissions

Reprints and Permissions

About this article

Further reading