Analysis of anti-HIV-1 Tat hammerhead ribozyme catalytic activity. (Withdrawn).

The Human Immunodeficiency Virus (HIV-1) is a retrovirus that causes the Acquired Immune Deficiency Syndrome (AIDS). HIV-1 infects CD4+ cells, including T helper lymphocytes, the destruction of which renders the immune system and human body defenseless. AIDS treatments include drug and potential gene therapies. However, gene therapies are potentially curative, whereas drug therapies act by preventing infection of additional cells. In the area of gene therapy, ribozymes have been of particular interest. Ribozymes are small catalytic RNAs that specifically cleave single-stranded RNA targets. Our research includes the use of specifically designed anti-HIV-1 hammerhead ribozymes. These ribozymes are designed to cleave Tat mRNA from the HIV-1 strain NL43. Tat is a small virally encoded protein that is responsible for regulation of viral transcription. Furthermore, Tat interacts directly with its target sequence within the LTR and is therefore critical for viral replication. Anti-tat hammerhead ribozymes and non-catalytic control ribozymes targeted to four Tat mRNA target sequences were cloned into plasmid DNAs. Each ribozyme, along with the Tat substrate, was transcrit ed by in vitro assay. Ribozyme catalytic activity was measured in an in vitro cleavage reaction followed by analysis of the cleavage products by acrylamide gel electrophoresis.

Pamela L. Wall, William H. Jackson
Department of Biology and Geology
University of South Carolina