HLA-DR+ leukocytes acquire CD1 antigens in embryonic and fetal human skin and contain functional antigen-presenting cells.
Adequate numbers and functional maturity are needed for leukocytes to exhibit a protective role in host defense. During intrauterine life, the skin immune system has to acquire these prerequisites to protect the newborn from infection in the hostile external environment after birth. We investigated the quantitative, phenotypic, and functional development of skin leukocytes and analyzed the factors controlling their proliferation and trafficking during skin development. We show that CD45(+) leukocytes are scattered in embryonic human skin and that their numbers continuously increase as the developing skin generates an environment that promotes proliferation of skin resident leukocytes as well as the influx of leukocytes from the circulation. We also found that CD45(+)HLA-DR(high)CD1c(+) dendritic cells (DCs) are already present in the epidermis and dermis at 9 wk estimated gestational age (EGA) and that transforming growth factor beta1 production precedes Langerin and CD1a expression on CD45(+)CD1c(+) Langerhans cell (LC) precursors. Functionally, embryonic antigen-presenting cells (APCs) are able to phagocytose antigen, to up-regulate costimulatory molecules upon culture, and to efficiently stimulate T cells in a mixed lymphocyte reaction. Collectively, our data provide insight into skin DC biology and the mechanisms through which skin DCs presumably populate the skin during development.
Schuster
Christopher
C
Department of Dermatology, DIAID, 1090 Vienna, Austria.
Vaculik
Christine
C
Fiala
Christian
C
Meindl
Simone
S
Brandt
Oliver
O
Imhof
Martin
M
Stingl
Georg
G
Eppel
Wolfgang
W
Elbe-Bürger
Adelheid
A
D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology*; D015703:Antigens, CD / Q000378:metabolism; D018949:Antigens, CD1 / Q000378:metabolism*; D049109:Cell Proliferation; D017077:Culture Media, Conditioned / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D020405:Dermis / Q000166:cytology; D004622:Embryo, Mammalian / Q000166:cytology / Q000196:embryology / Q000276:immunology; D000078404:Epidermal Cells; D004926:Escherichia coli / Q000276:immunology; D006023:Glycoproteins / Q000378:metabolism; D006684:HLA-DR Antigens / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D019394:Ki-67 Antigen / Q000378:metabolism; D007801:Langerhans Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D037181:Lectins, C-Type / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000378:metabolism; D007962:Leukocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D007959:Lymphocyte Culture Test, Mixed; D037241:Mannose-Binding Lectins / Q000378:metabolism; D010587:Phagocytosis / Q000276:immunology; D012867:Skin / Q000166:cytology / Q000196:embryology / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
D015703:Antigens, CD; D018949:Antigens, CD1; C437944:CD1C protein, human; C419393:CD1a antigen; C121916:CD207 protein, human; D017077:Culture Media, Conditioned; D016207:Cytokines; D006023:Glycoproteins; D006684:HLA-DR Antigens; D019394:Ki-67 Antigen; D037181:Lectins, C-Type; D037241:Mannose-Binding Lectins; D053773:Transforming Growth Factor beta1; D017493:Leukocyte Common Antigens; C516769:PTPRC protein, human