title: Expression of HLA class I and II (DR, DP and DQ) determinants in fetal and postnatal salivary glands.
abstract: Fetal (n = 20) and postnatal (n = 40) parotid glands were examined by two-colour immunohistochemistry combining monoclonal and polyclonal antibody reagents to study the expression of HLA class I and II (DR, DP, and DQ), CD45 and CD3. The epithelium lacked class II during fetal life, whereas class I determinants appeared in some acini and most major ducts. Fetal vessels were positive for both class I and class II (mainly DR), suggesting constitutive expression. Some class II-positive (DR greater than DP greater than DQ) histiocytic cells, scattered CD45+ leucocytes, and very few CD3+ T cells were present in the fetal stroma. The epithelium remained DR-negative the first few weeks after birth, but brisk expression was seen subsequently. DP and DQ remained virtually negative in the epithelium throughout the first year. A slight postnatal increase of class II expression (DR greater than DP greater than DQ), along with an apparent decrease in class I, was observed in the endothelium. The number of class II-positive histiocytic cells, CD45+ leucocytes and CD3+ T cells, as well as the proportion of presumably activated (DR+) T cells, increased a few weeks after birth. The local immune system hence seemed to be stimulated by extrinsic factors, but the overall number of T cells nevertheless remained small. Stimuli other than T cell-derived lymphokines, therefore, probably explained the brisk postnatal epithelial DR induction.
authors.affiliation: Laboratory for Immunohistochemistry and Immunopathology (LIIPAT), Medical Faculty, National Hospital, Rikshospitalet, Oslo, Norway.
authors.forename: P S
authors.initials: PS
authors.lastname: Thrane
authors.forename: T S
authors.initials: TS
authors.lastname: Halstensen
authors.forename: T O
authors.initials: TO
authors.lastname: Rognum
authors.forename: P
authors.initials: P
authors.lastname: Brandtzaeg
mesh_terms: D015703:Antigens, CD / Q000032:analysis; D005260:Female; D005333:Fetus / Q000276:immunology*; D006684:HLA-DR Antigens / Q000032:analysis; D006649:Histocompatibility Antigens / Q000032:analysis; D015395:Histocompatibility Antigens Class I / Q000032:analysis*; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007371:Interferon-gamma / Q000494:pharmacology; D017493:Leukocyte Common Antigens; D008297:Male; D011247:Pregnancy; D012469:Salivary Glands / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D015703:Antigens, CD; D006684:HLA-DR Antigens; D006649:Histocompatibility Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D017493:Leukocyte Common Antigens