Pilot Award Recipient: Sergey Iordanskiy, PhD, MS

Proteomics of the Host Proteins Associated with HIV-1 Pre-integration Complexes
March 15, 2011

HIV is capable to infect non-dividing cells and translocate a DNA copy of its RNA genome through the nuclear envelope to the site of integration in the host cell chromatin. This is an essential and vulnerable step of HIV infection which requires participation of a suite of host proteins and other cofactors. Therefore, the nuclear import events represent a promising target for anti-HIV interventions. However, the molecular machinery responsible for intracellular trafficking of the early subviral particles called pre-integration complexes (PICs) has not been fully characterized. Available data indicate that host proteins interacting with the HIV-1 PICs are different in different types of susceptible target cells - T lymphocytes and macrophages. The long-term goal of our studies is to identify the host cell cofactors and pathways which are critical for the successful HIV-1 replication in natural HIV targets. This pilot project represents the first step towards this goal and aims to identify the profiles of host proteins associated with the HIV-1 PICs in the HIV susceptible cells. To attain this objective we will (1) identify the cellular proteins associated with HIV-1 PICs in the T lymphocytes and macrophages using the proteomic approach; and (2) assess expression of PIC-interacting proteins and specificity of their association with HIV-1 PICs in the target cells. A very low abundance of PICs in the cell represents the major challenge for this analysis. We propose to optimize methods of purification of HIV-1 PICs and utilize state of the art molecular techniques for analysis. The high resolution mass spectrometry using the technical base of the new proteomics facility at the Howard University, a proposed part of the DC D-CFAR Basic Science Core, will be utilized for PIC proteomic profiling and subsequent bioinformatic analysis for validation of acquired data. The results of this study will determine the spectra of cell type-specific proteins involved in early stage of HIV-1 infection. Once this study identifies new host proteins associated with PICs, an R21 proposal will be submitted to investigate the mechanism of action of these factors.