Vpx of SIV modulates expression of innate immune target genes by inhibition of NF-κB activation

ABSTRACT: Background: In contrast to HIV-1, lentiviruses of the HIV-2/SIVmac/SIVsmm lineage are capable of efficient replication in myeloid cells due to the presence of their accessory protein Vpx. Vpx has been shown to induce degradation of the dNTP triphosphohydrolase SAMHD1, which is a cellular restriction factor of lentiviral replication. Furthermore, Vpx is important for nuclear import of the viral pre-integration complex. To identify further functions of Vpx, we have analyzed the effect of Vpx on cellular gene expression in monocytes. Therefore, we performed whole genome microarray analysis of unstimulated primary human monocytes treated with SIV–based virus-like particles containing Vpx (VLP+Vpx) or lacking Vpx (VLP). Results: Comparison of the gene expression profiles of human monocytes treated with VLP+Vpx and VLP revealed that Vpx down-regulates various genes involved in innate immunity, in particular genes that are known to be regulated by the transcription factor NF-κB. Subsequent analysis of p65 nuclear translocation revealed that Vpx inhibits the VLP-induced activation of NF-κB. Counteraction of NF-κB was also obtained using Vpx mutants lacking the capacity to induce SAMHD1 degradation. Conclusions: Independent of its capacity to induce degradation of SAMHD1, Vpx is involved in regulation of cellular gene expression. In particular, Vpx is able to modulate innate immune responses through down-regulation of TLR-induced NF-κB activation. This points to a significant role of Vpx in the pathogenicity of SIV, as the lower pathogenicity of SIV compared to HIV-1 has been associated to lower innate immunity responses.

ORGANISM(S): Homo sapiens

PROVIDER: GSE48542 | GEO | 2014/06/28

SECONDARY ACCESSION(S): PRJNA210512

REPOSITORIES: GEO