Intracellular immunization against SIVmac utilizing a hairpin ribozyme

Area of Science:

• Molecular Biology
• Virology
• Gene Therapy

Background:

• The 3' LTR region of SIVmac238 is a conserved target site.
• Simian immunodeficiency virus (SIV) and human immunodeficiency virus type 2 (HIV-2) share conserved sequences.
• Ribozymes offer a potential gene-silencing mechanism against viral infections.

Purpose of the Study:

• To develop and evaluate a hairpin ribozyme for targeting SIV and HIV-2.
• To assess the ribozyme's efficacy in conferring resistance to viral infection.
• To determine the ribozyme's impact on proviral DNA levels.

Main Methods:

• Cloning a hairpin ribozyme targeting the SIV 3' LTR into a retroviral vector.
• Transducing hybrid human B-/T-cell lines (CEM/174) with the construct.
• Selecting for G418 resistance to establish stable cell lines expressing the ribozyme.

Main Results:

• Stable expression of the 9456 ribozyme conferred long-term resistance to pathogenic SIV and two HIV-2 strains.
• The ribozyme effectively reduced the proviral DNA burden in infected cells.
• Cells expressing the ribozyme showed significant protection against SIV/HIV-2 infection.

Conclusions:

• Hairpin ribozymes targeting conserved viral sequences are effective against SIV and HIV-2.
• Ribozyme gene therapy shows promise for controlling SIV/HIV-2 replication.
• This study represents a significant step towards evaluating ribozyme gene therapy in primate models.