title: Stimulation of HLA-A,B,C by IFN-alpha. The derivation of Molt 4 variants and the differential expression of HLA-A,B,C subsets.
abstract: Spontaneous mutants with altered HLA-A,B,C response to interferon-alpha (IFN-alpha) were isolated from the human thymus leukemia cell line Molt 4. Using fluorescein isothiocyanate (FITC)-conjugated W6/32 (a monoclonal antibody to HLA-A,B,C) and the fluorescence-activated cell sorter, the cells with highest and lowest fluorescence after 24-48 h of IFN-alpha treatment were selected and expanded. After several cycles of selection, mutant clones with low (greater than 10% of wild-type) and high (three times better) response were obtained. A similar protocol was employed to derive high responder mutants with the monoclonal antibody YT76, which recognises a subset of HLA strongly induced by IFN-alpha. Stable clones were derived for which YT-HLA induction was 7-fold that of Molt 4 cells and for which HLA induction occurred at 100-fold lower concentrations of IFN-alpha. The high response phenotype of the mutants was not accompanied by a significant increase in the constitutive level of expression of HLA-A,B,C (in the absence of IFN). The increase in the level of HLA-A,B,C expression after IFN-alpha treatment is mostly accounted for by the increase in the expression of a subset of HLA molecules, detected by the monoclonal antibody YT76 including HLA-B molecules.
mesh_terms: D002460:Cell Line; D005796:Genes / Q000187:drug effects*; D014644:Genetic Variation; D006680:HLA Antigens / Q000235:genetics*; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology*; D007700:Kinetics; D007945:Leukemia, Lymphoid / Q000276:immunology; D009154:Mutation; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D006680:HLA Antigens; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens; D007370:Interferon Type I; D012333:RNA, Messenger