Neutrophil Receptor Response to Bacterial N-formyl Peptides is Similar in Term Newborn Infants and Adults in Contrast to IL-8.
We have previously observed that neutrophils from neonates exhibit different migratory responses to intermediate and end-target chemoattractants compared to adults. The aim of this study was to investigate the effect of the chemoattractants IL-8 (intermediate) and formyl-methionyl-leucyl-phenylalanine (fMLP; end-target) on cell surface receptor expression involved in adhesion, migration and granule release of neutrophils from term newborn infants and adults. Heparinized cord blood from 16 healthy term newborn infants delivered by caesarean section and peripheral blood from 17 healthy adults were incubated with 1 μm IL-8 or 0.1 μm fMLP, previously defined as optimal inducers of neutrophil migration. The leukocytes were labelled with antibodies to cell surface receptors (CD11b, CD15S, CD18, CD35, CD44, CD64, CD65, CD88, CD162, CD181 and CD182). Receptor expression was quantified by flow cytometry analysis. Upregulation of CD11b and downregulation of CD88 and CD182 after stimulation with IL-8 were more pronounced in adults than in neonates (P < 0.05, P < 0.05 and P ≤ 0.001, respectively), whereas fMLP induced changes in receptor expression that were of the same magnitude in neutrophils from neonates as from adults. We observed similar expression of receptors that mediate adhesion, migration, granule activation and phagocytosis induced by fMLP in neutrophils from neonates and adults. In contrast, differences between neonates and adults, induced by IL-8, suggest that the neutrophil response to intermediate chemoattractants might lead to a compromised infectious response in newborn infants.
Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
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Stålhammar
Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
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Sindelar
Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
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Douhan Håkansson
D000293:Adolescent; D000328:Adult; D000368:Aged; D039481:CD11b Antigen / Q000378:metabolism*; D002448:Cell Adhesion; D015550:Cell Degranulation; D002465:Cell Movement; D002478:Cells, Cultured; D006801:Humans; D007231:Infant, Newborn; D016209:Interleukin-8 / Q000276:immunology; D008875:Middle Aged; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000276:immunology; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism*; D010587:Phagocytosis; D044087:Receptor, Anaphylatoxin C5a / Q000378:metabolism*; D023063:Receptors, Interleukin-8B / Q000378:metabolism*; D055815:Young Adult
C488033:C5AR1 protein, human; D039481:CD11b Antigen; C509295:ITGAM protein, human; D016209:Interleukin-8; D044087:Receptor, Anaphylatoxin C5a; D023063:Receptors, Interleukin-8B; D009240:N-Formylmethionine Leucyl-Phenylalanine