Bystander Effect Seen After Vector Administration.(Brief Article)

2001 OCT 10 - (NewsRx.com & NewsRx.net) --

by Sonia Nichols, senior medical writer - Gene therapies containing herpes simplex enzymes might be useful for immunizing patients against the formation of new tumors, according to scientists working in the U.S.

A team led by researchers at the National Human Genome Research Institute of Bethesda, Maryland, has reported gene therapy vectors expressing herpes simplex thymidine kinase (HSVtk) tend to boost some parts of the immune system, essentially preventing the formation of new tumors as well as killing existing tumors.

"We have observed the development of cytotoxic T lymphocyte (CTL) populations and long-lasting antitumor immunity following treatment of subcutaneous tumors with an adenoviral vector expressing HSVtk (AV.TK) and ganciclovir (GCV) in rat glioma model," explained T. Okada and colleagues of Japan's Jichi Medical School and the U.S. genome investigation facility.

Investigators believe these vectors somehow stimulate important response cells of the immune system. In a manner similar to vaccination, the recipient of HSVtk gene therapy becomes immunized against the formation of additional tumors, while at the same time existing tumors are destroyed. Although these effects have been observed in animal models, similar effects ...