Massa PT, Wu H. Interferon regulatory factor element and interferon regulatory factor 1 in the induction of major histocompatibility complex class I genes in neural cells.
J Interferon Cytokine Res 1995;
15:799-810. [PMID:
8536108 DOI:
10.1089/jir.1995.15.799]
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Abstract
The role of the MHC-IRF-E and interferon regulatory factor 1 (IRF-1) in the regulation of MHC class I genes in astrocytes was analyzed. Transcriptional activation of MHC class I genes after treatment of astrocytes with various inducers occurred over a period of hours and correlated with cell surface expression. Functional analysis of the MHC class I gene promoter region confirmed that induction was controlled by a restricted region of 88 base pairs containing two well-defined inducible enhancers, the MHC-CRE and the MHC-IRF-E. Further analysis showed that potential MHC-CRE enhancer activity was silent. Therefore, the MHC-IRF-E, rather than the MHC-CRE, appeared responsible for enhancement of the MHC class I gene and was supported by three findings: (1) site-directed mutation of the MHC-IRF-E-abrogated induction, (2) promoter constructs containing IRF-Es as the sole enhancers were highly inducible in astrocytes, and (3) the expression of transcription factor IRF-1, which acts through the MHC-IRF-E to induce MHC class I genes, was induced to high levels in parallel with that of MHC class I induction. The induction of the IRF-1 gene correlated with the prior induction of the gamma-activated factor (GAF) or NF-kappa B, depending on the inducer, indicating that both gamma activation sites (GAS) and kappa B sites in the IRF-1 promoter are important.(ABSTRACT TRUNCATED AT 250 WORDS)
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