Impact of single nucleotide sequence configurations in stably integrated HIV-1 LTRs on gene expression, under basal and activating cellular phenotypes

Human immunodeficiency virus type 1 (HIV-1) gene expression is driven by the long terminal repeat (LTR), which has a variety of binding sites for the interaction with multiple viral and host factors, including members of the CCAAT/enhancer binding protein (C/EBP) and Sp transcription factor families...

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Published in:Journal of neurovirology 2007-01, Vol.13, p.123-123
Main Authors: Shah, S, Alexaki, A, Kilareski, E M, Nonnemacher, M R, Wigdahl, B
Format: Article
Language:English
Subjects:
Human immunodeficiency virus 1
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Summary:Human immunodeficiency virus type 1 (HIV-1) gene expression is driven by the long terminal repeat (LTR), which has a variety of binding sites for the interaction with multiple viral and host factors, including members of the CCAAT/enhancer binding protein (C/EBP) and Sp transcription factor families. Previous studies have identified specific nucleotide sequence configurations within C/EBP site I and Sp site III (3T, C-to-T change at position 3 of the binding site, and 5T, C-to-T change at position 5 of the binding site, respectively) which correlate with increased severity of HIV-1 disease and HIV-1-associated dementia. To begin exploring the LTR phenotype, associated with these genotypic changes, from an integrated chromatin-based microenvironment, a series of stably transfected cell lines have been developed utilizing bone marrow progenitor, T, and monocytic cell lines (TF-1, Jurkat, and U-937, respectively). Macrophage-, T cell-, and dual-tropic LTRs were coupled to the gene encoding green fluorescent protein (GFP) and polyclonal HIV-1 LTR-GFP stable cell lines were developed and examined under basal, and chemical or cytokine activation, as well as in the presence of Tat. The results demonstrate that the cell type and LTR backbone have a significant effect on the expression profiles. In addition, TF-1 cells the 3T/5T-containing LTR is associated with a lower expressing phenotype, however it can be induced to similar levels as the parental LTR, following stimulation and/or in the presence of Tat. Current studies are underway to examine the integration pattern and proviral DNA level utilizing uncloned and cloned HIV-1 LTR-GFP stably expressing cell lines.
ISSN:1355-0284