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 (Withdrawn).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