Modulation of major histocompatibility complex class 1 genes in human retinoblastoma cells by interferons.
OBJECTIVE
To examine the mechanism(s) of interferon (IFN) induced expression of major histocompatibility complex (MHC) class 1 molecules on the human retinoblastoma cell line, Y-79.


METHODS
Y-79 cells were incubated in the presence of IFN-alpha, -beta, and -gamma. Y-79 cell expression of MHC class 1 molecules was measured by flow cytometric analysis. HLA-B7 and oncogene transcription were evaluated by Northern blot analysis and nuclear runoff transcription assays.


RESULTS
IFN-gamma increased MHC-class 1 antigen expression and induced a fivefold increase in its transcription rate. Posttranscriptionally, IFN-beta and -gamma increased steady state messenger RNA for the HLA-B7 gene. These effects were not associated with down regulation of N-myc oncogene nuclear transcription. Moreover, dexamethasone did not affect the IFN-gamma induced expression of MHC-class 1 molecules.


CONCLUSIONS
Both transcriptional and posttranscriptional mechanisms are implicated in the modulation of class 1 molecule expression by IFN. In addition, this modulation is not associated with down regulation of N-myc oncogene expression. Spontaneous or IFN-gamma induced MHC class 1 antigen expression in retinoblastoma Y-79 cells is resistant to glucocorticoid hormones.
Barez
S
S
Immunology and Virology Section, National Eye Institute, National Institutes of Health, Bethesda, MD 20892.
Boumpas
D T
DT
Percopo
C M
CM
Anastassiou
E D
ED
Hooks
J J
JJ
Detrick
B
B
D015152:Blotting, Northern; D003907:Dexamethasone / Q000494:pharmacology; D005134:Eye Neoplasms / Q000378:metabolism*; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D005805:Genes, MHC Class I; D015793:HLA-B7 Antigen / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007372:Interferons / Q000494:pharmacology*; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012175:Retinoblastoma / Q000378:metabolism*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D015793:HLA-B7 Antigen; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D003907:Dexamethasone; D007372:Interferons