Host Factor Transcriptional Regulation Contributes to Preferential Expression of HIV Type 1 in IL-4–Producing CD4 T Cells

M Zhang, A Clausell, T Robinson, J Yin… - The Journal of …, 2012 - journals.aai.org
M Zhang, A Clausell, T Robinson, J Yin, E Chen, L Johnson, G Weiss, S Sabbaj, RM Lowe…
The Journal of Immunology, 2012journals.aai.org
Abstract HIV type 1 (HIV-1) replicates preferentially in IL-4–producing CD4 T cells for
unclear reasons. We show increased HIV-1 expression is irrespective of viral tropism for
chemokine receptors as previously suggested, but rather transcription of the HIV-1 long
terminal repeat (LTR) is increased in IL-4–producing CD4 T cells. Increased expression of
HIV-1 message is also confirmed in IL-4–producing CD4 T cells from HIV-1–infected
individuals ex vivo. In exploring a transcriptional mechanism, we identify a novel c-maf …
Abstract
HIV type 1 (HIV-1) replicates preferentially in IL-4–producing CD4 T cells for unclear reasons. We show increased HIV-1 expression is irrespective of viral tropism for chemokine receptors as previously suggested, but rather transcription of the HIV-1 long terminal repeat (LTR) is increased in IL-4–producing CD4 T cells. Increased expression of HIV-1 message is also confirmed in IL-4–producing CD4 T cells from HIV-1–infected individuals ex vivo. In exploring a transcriptional mechanism, we identify a novel c-maf (required for IL-4 expression) transcription factor binding site just upstream of the dual NF-κB/NFAT binding sites in the proximal HIV-1 LTR. We demonstrate that c-maf binds this site in vivo and synergistically augments HIV-1 transcription in cooperation with NFAT2 and NF-κB p65, but not NFAT1 or NF-κB p50. Conversely, small interfering RNA inhibition of c-maf reduces HIV-1 transcription in IL-4–producing T cells. Thus, c-maf increases HIV-1 expression in IL-4–producing CD4 T cells by binding the proximal HIV-1 LTR and augmenting HIV-1 transcription in partnership with NFAT2 and NF-κB p65 specifically. This has important implications for selective targeting of transcription factors during HIV-1 infection because, over the course of HIV-1 progression/AIDS, IL-4–producing T cells frequently predominate and substantially contribute to disease pathology.
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