title: HLA class II induction by interferon-gamma in K562 variant cell line: inhibition by serum lipid.
abstract: The induction of class II antigen (Ag) by interferon-gamma (IFN-gamma) in variants of the K562 cell line has been examined in this study. Following incubation of K562A cells with IFN-gamma, surface expression of HLA-DR molecules was demonstrated by indirect immunofluorescence, confirmed by immunoblotting, and HLA-DR3 Ag specificity identified. HLA-DP and HLA-DRW52 Ag were co-expressed, but no HLA-DQ expression occurred. A variant of this line, designated K1A, spontaneously developed resistance to IFN-gamma induction of class II Ag, but continued to express class I Ag. In a third K562 variant, designated K562B, no class II gene products could be induced. Northern blot analysis indicated that mRNA levels correlated with surface class I and II Ag expression in all of the K562 cell lines. Resistance to IFN-gamma inducible class II Ag expression in K1A cells did not involve changes in IFN-gamma receptor affinity or number but was shown to be due to an inhibitory effect of serum lipid. These results indicate that cells derived from a common parental line may differ in susceptibility to a regulatory mechanism affecting IFN-gamma inducible class II Ag expression.
authors.affiliation: Department of Medicine, University of Cape Town Medical School, Republic of South Africa.
authors.forename: S R
authors.initials: SR
authors.lastname: Ress
authors.forename: J
authors.initials: J
authors.lastname: Rousseau
authors.forename: B
authors.initials: B
authors.lastname: Ratanjee
authors.forename: K
authors.initials: K
authors.lastname: Eidne
authors.forename: R P
authors.initials: RP
authors.lastname: Millar
authors.forename: M
authors.initials: M
authors.lastname: Keraan
mesh_terms: D015152:Blotting, Northern; D002460:Cell Line; D006681:HLA-D Antigens / Q000096:biosynthesis*; D006682:HLA-DP Antigens / Q000096:biosynthesis; D006684:HLA-DR Antigens / Q000096:biosynthesis; D059810:HLA-DR Serological Subtypes; D015803:HLA-DR3 Antigen / Q000096:biosynthesis; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000276:immunology; D008055:Lipids / Q000097:blood / Q000502:physiology
chemical_list: D006681:HLA-D Antigens; D006682:HLA-DP Antigens; D006684:HLA-DR Antigens; D059810:HLA-DR Serological Subtypes; D015803:HLA-DR3 Antigen; C051104:HLA-DR52 antigen; D015395:Histocompatibility Antigens Class I; D008055:Lipids; D007371:Interferon-gamma