HIV-1 Transcription Inhibition Using Small RNA-Binding Molecules

Abstract

HIV-1 is a retrovirus that integrates its genetic code into an infected host cell’s DNA. HIV-1 replication occurs in cells with a key mechanism known as the Tat-TAR interaction. Tat, the HIV-1 transactivator protein, interacts with the transactivation response element (TAR), an element of viral RNA, to incite the engagement of an essential protein called transcription elongation factor-b (P-TEFb). This process allows transcription of the viral genome to begin. The most effective treatment for HIV-1 infection, known as combination antiretroviral therapy (cART), currently contains no means of inhibition for this transcription mechanism, thus presenting a gap in HIV-1 antiviral treatment. This study tests two small molecules that have previously demonstrated the ability to bind to HIV-1 TAR RNA and showed successful inhibition of viral protein expression. We used a biotinylation pull-down assay to test the disruption of Tat from TAR RNA interaction using these TAR-binding molecules, and we also used a chromatin immunoprecipitation (ChIP) assay to determine whether treatment with TAR-binding molecules affected occupancy of transcription factors on HIV-1 long terminal repeat (LTR) DNA, which is the initiation site for viral transcription.

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