Phagocytosis-Associated Functions in Neonatal Monocyte-Derived Macrophages

Abstract

A B S T R A n . 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), a-actinin (102,000) and actin (42,000) could be identified in cells from either source: ~l l phagocytic functions were shown to be perfectly normal in neonatal macrophages when compared with adult cells: random migration, chemotactic response to zymosanactivated serum and formyl-methionyl-leucyl-phenylalanin, ingestion, and killing of Staphylococcus aureus, phagocytosis-associated chemiluminescence, production of oxygen intermediates (superoxide anion, 0;; hydrogenperoxide, H202). Phorbol myristate acetate-stimulated 0;-generation by 1 x lo5 macrophages was 11.8 f 4.7 nmol/h for neonates, and 10.2 f 3.9 for controls; production of H 2 0 2 was 7.6 f 3.5 nmol/h in neonatal macrophages and 6.4 +. In newborns, who suffer an increased susceptibility to serious systemic infections, subnormal phagocyte functions have been described. Neutrophils from neonates showed a decreased deformability (1) and a marked deficiency in movement toward different chemotactic stimuli (2-6). In addition generation of .OH by neonatal neutrophils was shown to be decreased (7). However, neonatal monocytes exhibited basically normal phagocytic functions when compared with adult cells (8). The functions of neonatal macrophages have not been fully explored. Macrophages from newborns synthesize humoral host defense factors such as complement components C2, C4 to a similar extent as phagocytes from adults (9, 10); fibronectin production Received October 12, 1987; accepted April 7, 1988. Correspondence Christian P. Speer, M.D., Universitats-Kinderklinik, RobertKoch-Str. 40, D-3400 Gottingen, Federal Republic of Germany.Supported by Grant Sp 239/2-2 from the Deutsche Forschungsgemeinschaft.2 1 was shown to be decreased in neonatal macrophages (9). Macrophages from newborns who had been activated by interferon-7 effectively killed or inhibited replication of toxoplasma gondii (1 I), presentation of bacterial Ag, and production of interleukin 1 was normal in cord blood monocytes/macrophages (12, 13). However, it has been suggested, that the decreased production of interferon-y by human neonatal cells (13) could be due to a functionally immature macrophage (14). Our study was initiated to examine the principal phagocyte activities of monocyte-derived macrophages in response to inflammation, i.e. chemotaxis, phagocytosis, killing, and generation of oxygen metabolites. Momholonical studies included a detailed analysis of the protein compos~ion of macrophages. MATERIALS AND METHODS Cell separation. Umbilical venous blood was withdrawn fromthe placenta into heparin (1-20 U/ml) immediately after delivery of healthy term newborns who were products of an uncomplicated pregnancy, normal labor, and...

Oxidant-antioxidant balance in alveolar macrophages from newborn rats

“…These results are, at first sight, at variance with the report by SPEER et al [13], who found similar oxygen metabolite production in neonatal and adult monocytederived macrophages in a study involving testing of macrophages after a long incubation period (7 days). However, as demonstrated by NERURKAR et al [14], such a delay is associated with an overall loss in antioxidant enzyme activities in cells.…”

“…Decreased oxidant production by neonatal macrophages has been found in some studies [10][11][12], but not in others [13]. Similarly, studies of AM intracellular antioxidants are contradictory, showing either low SOD activity [14] or high SOD activity [15] immediately after birth.…”

Responsiveness of human monocytes to the commensal bacterium Staphylococcus epidermidis develops late in gestation

“…Phagocytosis and intracellular killing by neonatal monocytes are comparable to those achieved by adult MNCs (25)(26)(27)(28)(29). However, these data are derived from stimulation studies using early-onset sepsis pathogens or latex particles; there are no analogous data on phagocytosis of SE by monocytes in preterm infants.…”

Phagocytic Functions and Tumor Necrosis Factor Secretion of Human Monocytes Exposed to Natural Porcine Surfactant (Curosurf)

“…Monocytes from healthy adult donors were isolated by FicollHypaque density gradient and purified by adherence and a 24-h cultivation in Teflon culture bags at 37°C in 5% C02/95% air (10). The resulting cell preparation contained about 90% monocytes identified by nonspecific esterase stain (Technicon, Terry Town, New Jersey).…”

“…Phagocytosis and bactericidal activity. A modification of the method of Quie and coworkers was used (10). Phagocytosis by monocytes was determined as the decrease in the number of viable extracellular bacteria (S. aureus 502 A) during incubation of bacteria and monocytes in the presence of serum.…”