Allele-specific long-distance regulation dictates IL-32 isoform switching and mediates susceptibility to HIV-1

作者:Palstra Robert Jan*; de Crignis Elisa; Roling Michael D; van Staveren Thomas; Kan Tsung Wai; van Ijcken Wilfred; Mueller Yvonne M; Katsikis Peter D; Mahmoudi Tokameh*
来源:Science Advances, 2018, 4(2): e1701729.
DOI:10.1126/sciadv.1701729

摘要

We integrated data obtained from HIV-1 genome-wide association studies with T cell-derived epigenome data and found that the noncoding intergenic variant rs4349147, which is statistically associated with HIV-1 acquisition, is located in a CD4(+) T cell-specific deoxyribonuclease I hypersensitive region, suggesting regulatory potential for this variant. Deletion of the rs4349147 element in Jurkat cells strongly reduced expression of interleukin-32 (IL-32), approximately 10-kb upstream, and chromosome conformation capture assays identified a chromatin loop between rs4349147 and the IL-32 promoter validating its function as a long-distance enhancer. We generated single rs4349147-A or rs4349147-G allele clones and demonstrated that IL-32 enhancer activity and interaction with the IL-32 promoter are strongly allele dependent; rs4349147 -/A cells display reduced IL-32 expression and altered chromatin conformation as compared to rs4349147 G/- cells. Moreover, RNA sequencing demonstrated that rs4349147 G/- cells express a lower relative ratio of IL-32 alpha to non-a isoforms than rs4349147 -/A cells and display increased expression of lymphocyte activation factors rendering them more prone to infection with HIV-1. In agreement, in primary CD4(+) T cells, both treatment with recombinant IL-32 gamma (rIL-32 gamma) but not rIL-32 alpha, and exogenous lentiviral overexpression of IL-32 gamma or IL-32 beta but not IL-32 alpha resulted in a proinflammatory T cell cytokine environment concomitant with increased susceptibility to HIV infection. Our data demonstrate that rs4349147-G promotes transcription of non-IL-32 alpha isoforms, generating a proinflammatory environment more conducive to HIV infection. This study provides a mechanistic link between a HIV-associated noncoding DNA variant and the expression of different IL-32 isoforms that display discrete anti-HIV properties.

  • 出版日期2018-2