LOS ANGELES: American scientists have
created HIV-resistant cells that could one day pave the way for controlling the
virus without using harsh anti-retroviral drugs.
Scientists at the
Keck School of Medicine, at the University of Southern California, used mice to
test the cells that target one of the two "gateway" molecules that the Human
Immunodeficiency Virus (HIV) uses to enter human cells, Meghan Lewit,
spokeswoman for the team of researchers, said.
The researchers
modified blood stem cells to make them resistant to HIV and then transplanted
them into the mice, enabling the rodents to control the infection.
If the approach can be applied to humans, it could enable a
long-term generation of HIV-resistant cells in the body, providing the potential
for the patient's cells to suppress HIV, Lewit said.
"This hybrid
gene and stem cell therapy show that it is possible to create HIV-resistant
immune cells that can eventually win the battle against HIV," Paula Cannon,
principal investigator and associate professor of molecular microbiology and
immunology, was quoted as saying by Xinhua.
"We've done it at the
scale of a mouse, and the challenge now is to see if this can be done at the
scale of a human patient."
"The strategy arose from the observation
that people with a mutation in a gene called CCR5 are naturally resistant to
infection with the most common strains of HIV and do not develop AIDS," Lewit
said.
Researchers used enzymes to knock out the CCR5 gene in human
blood stem cells, and then transplanted the modified stem cells into mice, Lewit
said.
The cells developed into mature cells of the human immune
system, including the T cells that HIV infects. And when they infected the mice
with HIV, the animals were able to maintain normal levels of the human T cells
and suppress HIV.
"By engineering CCR5-deficient stem cells, we may
allow a patient to produce HIV-resistant cells in all of the cell types that the
virus infects, and for long periods of time," Cannon said.
"If
successful, it could one day allow patients to control their HIV without needing
to take anti-retroviral drugs."
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