title: Phenotypic analysis of circulating dendritic cells during the second half of human gestation.
abstract: Dendritic cells (DCs) have been characterized as having an immature phenotype in infants when compared with adults; but it is unclear whether the phenotype or function of these populations changes during human intrauterine development. Three-colour flow cytometry was used to phenotype fetal/neonatal circulating DCs during the second half (>20-wk gestation) of pregnancy, (n = 34) and adults (n = 9). DCs were identified from peripheral blood mononuclear cells (PBMCs) or cord blood mononuclear cells (CBMCs) as staining brightly for HLA-DR but negative for T cell, B cell, monocyte, and NK cell lineage markers. The surface molecule of interest was detected in a third colour. During gestation CD34, a marker of immaturity was significantly higher, and CD4, a differentiation marker, was significantly lower than adult levels. The percentage of CD11c+ cells did not differ significantly at any age, although a trend to reduced intensity of expression at earlier stages of gestation was observed. Significantly fewer DCs expressed the IgG receptors CD32 and CD64 at all gestations. The percentage of HLA-DR+/lin- cells expressing CD40 was lowest at 20-23 wks and was always significantly lower on DCs from cord blood vs. adult blood. Similarly, the percentage of CD86+ and CD54+ DCs was significantly lower than adults throughout gestation. Thus, immaturity of cord blood DCs is likely to arise as a consequence of decreased ability to take up antigen (at least via IgG-mediated mechanisms) and reduced provision of co-stimulation.
authors.affiliation: School of Medicine, University of Southampton, Southampton, UK. j.holloway@soton.ac.uk
authors.forename: Judith A
authors.initials: JA
authors.lastname: Holloway
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Thornton
authors.forename: Norma D
authors.initials: ND
authors.lastname: Diaper
authors.forename: David T
authors.initials: DT
authors.lastname: Howe
authors.forename: John O
authors.initials: JO
authors.lastname: Warner
mesh_terms: D037881:Aborted Fetus / Q000276:immunology*; D000328:Adult; D000943:Antigens, Differentiation / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D001773:Blood Cells / Q000166:cytology; D002454:Cell Differentiation / Q000276:immunology; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D005260:Female; D047109:Fetal Development / Q000276:immunology*; D006801:Humans; D007107:Immune System / Q000196:embryology* / Q000276:immunology; D016130:Immunophenotyping; D007231:Infant, Newborn; D011247:Pregnancy; D013997:Time Factors; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D000943:Antigens, Differentiation