HIV-1 genome-encoded hiv1-mir-H1 impairs cellular responses to infection.

The recent discovery of HIV-1 genome-encoded novel microRNA (miRNA; designated as hiv1-mir-H1) having ability to target selectively and specifically human cellular AATF gene, prompted us to explore the role of this miRNA in the regulation of genes involved in cellular apoptosis, proliferation and nucleic acid-based immune mechanism governed by miRNAs. Such a study revealed that this miRNA-induced knockdown of AATF gene, within normal human blood mononuclear cells, was responsible for the suppression of genes coding for Bcl-2, c-myc, Par-4 and Dicer. Further, hiv1-mir-H1 had the capacity to downregulate expression of cellular miR149 gene recognized to target Vpr gene encoded by HIV-1. Based upon these findings, we propose an "Epigenomic Pathway" through which hiv1-mir-H1 induced AATF gene knockdown within human mononuclear cells initiates their apoptosis.