title: Postnatal maturation of total cell content and up-regulated surface expression of Mac-1 (CD11b/CD18) in polymorphonuclear leukocytes of human infants.
abstract: Markedly deficient expression of membrane-activated complex 1 (Mac-1; CD11b/CD18) by polymorphonuclear neutrophils (PMN) of human neonates compared with adults is well documented. To define postnatal maturation of Mac-1 expression of PMN, lysates of PMN from 21 infants, aged 1-14 months, and concurrent adult controls were assayed by ELISA for total cell content of Mac-1 and LFA-1 (CD11a/CD18), and LFA-1 content was within the normal adult range at all ages tested. Mac-1 content was approximately 50% of adult levels for infants 1-2 months of age and steadily increased to reach normal adult levels by 11-12 months of age. For a separate group of 25 infants, aged 0.5-11 months, measurement of surface expression of Mac-1 and LFA-1 on activated PMN by immunofluorescence flow cytometry yielded results that were similar to those obtained by ELISA.
authors.affiliation: Department of Pediatrics, Case Western University, Cleveland, Ohio, USA.
authors.forename: Shawn W
authors.initials: SW
authors.lastname: Storm
authors.forename: M Michele
authors.initials: MM
authors.lastname: Mariscalco
authors.forename: Michael F
authors.initials: MF
authors.lastname: Tosi
mesh_terms: D000328:Adult; D000375:Aging / Q000276:immunology; D002462:Cell Membrane / Q000276:immunology*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016177:Macrophage-1 Antigen / Q000235:genetics*; D009504:Neutrophils / Q000276:immunology*; D015854:Up-Regulation
chemical_list: D016177:Macrophage-1 Antigen