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Biomedical subjects

A Dolei

Publications and source records attributed to A Dolei.

At least 55 records · Page 3Linked to original sources
PubMed1983

Human interferon-gamma enhances the expression of class I and class II major histocompatibility complex products in neoplastic cells more effectively than interferon-alpha and interferon-beta.

Human interferon-gamma was more effective than interferon-beta or -alpha in stimulating production of immunoassociated antigens; HLA-A, -B, and -C; and beta(2)-microglobulin in human M14 and Namalva cells. The comparison was made on the basis of antiviral units, and the stimulation could be abolished by treatment of the interferon-gamma preparation with pH 2 or anti-interferon-gamma serum.

Animals↗
PubMed1983

Differential effects of gamma interferon on expression of HLA class II molecules controlled by the DR and DC loci.

Interferon-gamma affected the expression of the products of the immunoassociated antigen complex by a differential modulation of DR- and DC-locus-controlled molecules. In melanoma M14 cells treated with interferon-gamma, levels of DR molecules were increased two- to threefold, whereas levels of DC molecules were increased six- to sevenfold. Similar effects were induced on the two allelic products of each locus.

Cell Line↗
PubMed1980

Interferon effects on Friend leukaemia cells. I. EXpression of virus and erythroid markers in untreated and dimethyl sulphoxide-treated cells.

The effects of low doses (40 to 1000 units/ml) of mouse interferon (IF) on the expression of Friend leukaemia virus (FLV) and globin genes in Friend leukaemia cells (FLC) have been examined. IF blocks production of extracellular virus, but virus antigens accumulate in the cytoplasm. In cells treated with IF at the time of seeding, there is a reduction in the amount of RNA specified by the lymphatic leukaemia virus (LLV) component of FLV; with the same IF dose there is a small but definite stimulation of haemoglobin and globin mRNA synthesis. The effects of IF on LLV gene expression are even more pronounced in dimethyl sulphoxide (DMSO)-stimulated LFC. No correlation was found between LLV gene expression and the appearance of erythroid markers.

Antigens, Viral↗
PubMed1979

Nuclear RNA sequences coding for alpha and beta globins in erythroid cells: evidence for multiple intermediate molecules.

The poly (A)-containing nuclear RNA from dimethylsulfoxide-induced Friend leukemia cells was fractionated by acrylamide gel electrophoresis in denaturing conditions and analyzed for alpha and beta globin RNA sequences. The results indicate that nuclear RNA contains one species of large-size RNA (0.6 X 10(6) daltons), which is the putative precursor for beta globin mRNA only. In addition, it was shown by electrophoretic analysis that the complex of RNA molecules not resolved by sucrose gradient centrifugation (11S) comprises sequences of decreasing size (0.34, 0.28, and 0.26 X 10(6) daltons), which might be the precursors of alpha and beta globin mRNA.

Erythrocytes↗
PubMed1977

Inhibition of transcription and translation of globin messenger RNA in dimethyl sulfoxide-stimulated Friend erythroleukemic cells treated with interferon.

The addition of appropriate doses of interferon (IF) to cultures of Friend erythroleukemic cells inhibits dimethyl sulfoxide (Me2SO)-stimulated erythroid differentiation. In this study, the synthesis of heme, hemoglobin, and globin mRNA in Me2SO-stimulated cultures, with or without IF added, was compared. Although the hemoglobin content in Me2SO+IF-treated cultures was reduced 6- to 9-fold compared to that of cultures treated with Me2SO alone, there was less than a 2-fold decrease in the amount of heme accumulated. Globin mRNA, although unchanged in size or base sequence, was reduced in content in the Me2SO+IF cultures. The level of reduction of globin mRNA was insufficient to account for the lack of globin synthesis. Thus, it appears that IF may operate on two levels--one involving the transcription of globin mRNA and the other involving its translation.

Animals↗
PubMed1977

Low-molecular-weight peptide inhibits RNA synthesis in human leukemic and phytohemagglutinin-stimulated leukocytes and globin mRNA transcription in differentiating Friend cells.

The RNA synthesis of human leukemic leukocytes and phytohemagglutinin-stimulated lymphocytes is markedly reduced by administration of a low-molecular-weight nonhistone peptide factor from calf thymus. Treatment with the factor strongly inhibits hemoglobin production and globin mRNA transcription in dimethyl sulfoxide-stimulated Friend cells without appreciably modifying the rate of cell growth. Evidence for specificity of these effects is provided by the lack of action of the factor on both growth rate and RNA synthesis of a number of nondifferentiating cell lines from various animal species. After removal of the compound, both human lymphocytes and Friend cells can be stimulated by phytohemagglutinin and by dimethyl sulfoxide, respectively, ruling out any toxic effect.

Animals↗
PubMedDate not supplied

Anti-interferon-gamma antibodies in sera from HIV infected patients.

High serum levels of antibodies to interferon-gamma (IFN-gamma) have been found in patients infected with human immunodeficiency virus (HIV). A radioimmunoassay (RIA) with a recombinant IFN-gamma protein or an affinity purified IFN-gamma preparation as antigens, was developed to detect the specific anti-IFN-gamma antibodies. Reactivity of sera to IFN-gamma was confirmed by Western blot analysis. These antibodies, however, do not seem to recognize the active site of the molecule, since they do not neutralize the antiviral IFN-gamma activity in a biological assay. These results enforce the hypothesis of the role of autoimmunization during the course of the disease.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Recombinant interferon alpha-2 modulates hairy cell phenotype "in vitro".

The "in vitro" effect of IFN-alpha on the phenotypic profile of atypical cells from 5 hairy cell leukemia patients was investigated in a 72 hr culture assay. Cytochemical investigations revealed a dramatic decrease in the cytoplasmic content of acid phosphatase and tartrate resistant acid phosphatase in the absence of any apparent morphological modification. Flow cytometry showed that IFN-alpha markedly reduced the density of surface Ig without modifying the original isotype pattern. The expression of the receptor for the Fc fragment of IgG was also reduced. The class II MHC antigen recognized by the monoclonal antibody 12 remained essentially unchanged. Hairy cells were negative for OKT10 and PCA-1 and remained so after IFN-alpha incubation. Present data indicate that IFN-alpha is able to consistently and selectively affect membrane and cytoplasmic features of hairy cells in a short term period. The possibility is envisaged that these changes may be related to the therapeutic efficacy of IFN-alpha.

Adult↗