Women's Health Research Day 2006

GENE THERAPY AGAINST HSV INFECTION.

Liu, Jia; Bloom, David, Ph.D; Tuli, Sonal, MD; Schultz, Gregory, Ph.D; Ghivizzani, Steve, Ph.D; Lewin, Alfred, Ph.D; Molecular Genetics and Microbiology, University of Florida.

Herpes Simplex Virus type 2 (HSV-2) causes genital infection with significant morbidity particularly in women, while HSV-1 is responsible for orofacial and ocular infection. HSV-2 infection accounts for higher risk of HIV transmission and cervical cancer in women and HSV-1 ocular infection is the most common cause of corneal blindness in the U.S. HSV-2 seroprevalence is higher among women (25.9%) than men (17.8%) of the United States population. If present trends in America continue, researchers estimate that 49% of women aged 15 to 39 will be infected with HSV-2 versus 39% of males aged 15 to 39 by 2025. It is the repeated infection from reactivation of the virus that causes series of diseases. Currently there is no viable cure to recurrent HSV infection. We designed an oligonucleotide therapy using ribozyme/siRNA to eliminate HSV infection which is the origin of disease pathogenesis.
Methods: Ribozymes and siRNAs were designed targeting mRNAs of HSV essential genes. Transfection of siRNA was conducted before infection of wtHSV-2 virus in HeLa cells. And ribozymes were studied in vitro for their catalytic activities and the ones with better parameters were chosen for cell and animal tests. Adenovirus packaged ribozymes were tested against wtHSV-1 in RS cells and a chemical protected ribozyme was tested in a rabbit ocular infection model.
Results:  siRNA transfection significantly reduced HSV-2 viral yield by 70% at 2 days post-infection. And an Adenovirus packaged ribozyme inhibited HSV-1 viral replication by 83% at 1 day post-infection and the effect maintained for 6 days with 98% reduction of viral yield in RS cells. This effect was caused by ribozyme degradation of target mRNA indicated in RT-real-time PCR. Ribozyme significant protected animals from ocular lesion by HSV-1 infection.
Discussion: Ribozyme/siRNA significantly eliminated HSV replication not only in cell culture but in animals. This shed the light for a future therapy against herpes diseases.

Sponsor: NIH Grant EY05587, NIH Grant AI48633