Zinc Finger Protein Designed to Target 2-LTR Junctions Interferes with HIV Integration

• Main Authors: Tayapiwatana C., Sakkhachornphop S., Barbas Iii CF., Keawvichit R., Wongworapat K.
• Format: Article
• Language: English
• Published: 2014
• Online Access: http://www.ncbi.nlm.nih.gov/pubmed/3502482; http://cmuir.cmu.ac.th/handle/6653943832/799
• Institution: Chiang Mai University

Integration of the human immunodeficiency virus type 1 (HIV-1) genome into the host chromosome is a vital step in the HIV life cycle. The highly conserved cytosine-adenine (CA) dinucleotide sequence immediately upstream of the cleavage site is crucial for integrase (IN) activity. As this viral enzyme has an important role early in the HIV-1 replication cycle, interference with the IN substrate has become an attractive strategy for therapeutic intervention. Recently, we demonstrated that a designed zinc finger protein (ZFP) fused to green fluorescent protein (GFP) targets the 2-long terminal repeat circle junctions of HIV-1 DNA with nanomolar affinity. We report now that 2LTRZFP-GFP stably transduced into 293T cells interfered with the expression of vesicular stomatitis virus glycoprotein (VSV-G)-pseudotyped lentiviral red fluorescent protein (RFP), as shown by the suppression of RFP expression. We also used a third-generation lentiviral vector and pCEP4 expression vector to deliver the 2LTRZFP-GFP transgene into human T-lymphocytic cells, and a stable cell line for long-term expression studies was selected for HIV-1 challenge. HIV-1 integration and replication were inhibited as measured by Alu-gag real-time PCR and p24 antigen assay, In addition, the molecular activity of 2LTRZFP-GFP was evaluated in peripheral blood mononuclear cells (PBMCs). The results were confirmed with Alu-gag real-time PCR for integration interferences. We address that the expression of 2LTRZFP-GFP limited viral integration upon intracellular immunisation, and it has potential for use in HIV gene therapy in the future.