单选题
A newly published AIDS study could open another
front in the battle against HIV infection by showing that gene therapy can be
used to stop infected cells from spreading the deadly virus, researchers
said. In a test-tube experiment believed to be the first of its
kind, researchers based at Children's Hospital of Philadelphia were able to
block the operation of the "tat" gene that allows HIV to spread throughout the
body from infected cells. Up to now, genetic AIDS research has
concentrated on finding ways to help healthy cells withstand the ravages of the
HIV virus that infects an estimated 16,000 new victims a day, mainly in the
developing world. But by working with human cells already
infected with HIV, the team was able to reduce the tat gene's virus-replicating
functions by 80 percent to 90 percent, according to findings published in the
journal Gene Therapy. That, researchers said, raises the
possibility of a new gene therapy approach capable of supplementing the current
drug-based treatment known as highly active antiretroviral therapy, or HAART,
which is used to stop HIV infection from becoming full-blown AIDS.
In recent studies, HAART has proved to be a costly drug regimen that
poses serious side effects for HIV patients while delivering questionable
results. "This is proof of the concept that HIV replication
could be inhibited by a genetic approach, though we're not at 100 percent yet,"
said Dr. Stuart Starr, a study coauthor and chief of immunologic infectious
diseases at Children's Hospital. "Everyone thinks of an
antiviral approach, or an immunologic approach (to HIV). This adds another
option into the equation that could become more important as other options prove
not to be totally successful." Key to the study was an
artificially produced "antitat" gene provided by the Washingtonbased Research
Institute for Genetic and Human Therapy. Children's Hospital
researchers used a mouse retrovirus to deliver the antitat gene into
HIV-infected U-1 and ACH-2 cells, which were developed in the lab from the
tissues of living HIV patients. They found that when the
antitat protein combined with the tat gene, it successfully inhibited the gene's
operation without disturbing healthy cells or causing toxic
side-effects. The study, funded by a private foundation, also
found that the introduction of the antitat gene prolonged the survival of
immune-system cells called CD4+T lymphocytes. Starr said
researchers have entered preliminary discussions with a New England-based
primate center, where animal experiments could be carried out on infected
macaque monkeys. If animal experiments proved successful, the
Children's Hospital team would hope to have a gene therapy treatment ready for
human clinical trials in three to four years.
单选题
What is the passage mainly about?
A. AIDS study raises hopes for gene therapy treatment.
B. A new killer of HIV virus.
C. Research on gene therapy.
D. Gene therapy proves to be the ultimate solution to HIV
infection.