Treating Congenital Problems With Gene Therapy In Utero Believed Possible.

2001 OCT 18 - (NewsRx.com & NewsRx.net) -- by Sonia Nichols, senior medical writer - Scientists believe birth defects detected while a fetus is in utero could be treated with therapies incorporating transduced stem cells administered before birth or shortly thereafter.

However, first, researchers must optimize stem cell transduction. A team at the University of California at San Francisco recently reported their experiences with retroviral transduction using stem cells obtained from the livers of fetuses. Their results suggest that with the right culture conditions, transduced cells remain a viable method for delivering gene therapies targeting birth defects.

Stem cells obtained from the livers of midtrimester fetuses were first sorted and isolated, according to T. Ohkubo and colleagues. Next, "A murine retroviral vector with a truncated human low-affinity nerve growth factor receptor (Delta NGFR) gene was used to transduce the candidate stem cells," researchers said.

Transduction procedures and culture conditions were then change in order to assess environmental influence. Some cells were transduced immediately following isolation, whereas others were allowed to grow and then transduced at 4 days postisolation. In addition, investigators supplemented the culture medium with a variety of growth factors and assessed the influence of centrifugation on the transduced cells, which they expanded for up to 21 days.

"Efficient transduction of candidate stem cells, at an average rate of 46%, was achieved after 3 days of culture with a single exposure to virus," Ohkubo noted. Further exposure after 3 days ...