title: Control of Ia antigen expression on phagocytic cells of the thymic reticulum by interferon-gamma and prostaglandins.
abstract: Phagocytic cells of the thymic reticulum (P-TR) spawned in the microenvironment of primary thymic stroma cultures express class II antigens on their membranes. We can show that Ia-antigen expression is regulated by the local secretion of interferon-gamma (IFN-gamma): (a) early primary culture supernatants contain IFN as tested by a cytopathogenic inhibition test after concentration of IFN activity; (b) the addition of a specific anti-IFN-gamma antiserum to primary cultures reduces Ia expression on P-TR suggesting that IFN-gamma produced in situ is implicated in Ia expression; (c) the percentage of Ia+ cells declines as primary cultures age. This phenomenon parallels the disappearance of thymocytes which are the supposed candidate for IFN-gamma secretion. (d) When isolated from their stromal environment and replated in secondary cultures, P-TR lose their membrane Ia antigen which can be re-expressed in the presence of recombinant IFN-gamma, but not IFN-alpha/beta. The decline of Ia expression on P-TR during the aging of primary cultures may be delayed by the inhibition of prostaglandin secretion.
authors.forename: M
authors.initials: M
authors.lastname: Papiernik
authors.forename: H
authors.initials: H
authors.lastname: Dombret
authors.forename: S
authors.initials: S
authors.lastname: Stefanos
authors.forename: J
authors.initials: J
authors.lastname: Wietzerbin
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D002469:Cell Separation; D002478:Cells, Cultured; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D000949:Histocompatibility Antigens Class II / Q000032:analysis* / Q000235:genetics; D007371:Interferon-gamma / Q000494:pharmacology*; D051379:Mice; D008811:Mice, Inbred DBA; D010586:Phagocytes / Q000276:immunology*; D011453:Prostaglandins / Q000096:biosynthesis / Q000494:pharmacology*; D011961:Receptors, Fc / Q000032:analysis; D013950:Thymus Gland / Q000166:cytology* / Q000276:immunology / Q000378:metabolism
chemical_list: D000949:Histocompatibility Antigens Class II; D011453:Prostaglandins; D011961:Receptors, Fc; D007371:Interferon-gamma