Jan. 29, 2007 — Severe burns are not only painful, they also put patients at risk of serious infection. Now researchers are using gene therapy to rev up the wound healing process in skin cells, hoping to fight potentially lethal infections.
"The gene we're using is found in humans, but not normally turned on
in the skin," explained Dorothy Supp, a researcher at Cincinnati Shriner's Hospital for Children and the University of Cincinnati. "We transferred it to skin cells in culture increase their
antimicrobial function."
Supp and her team
published the research in the current issue of the Journal of Burn
Care and Research.
The technique could prove especially therapeutic for patients with burns covering
more than half of their bodies.
In these cases, doctors often use
skin cells from the patient to grow more cells in a laboratory.
The new cells are then combined with a sponge-like substance
to make a cultured skin substitute.
The doctor uses the skin substitute as a graft, which the body recognizes as its own. The good news is that the body won't produce an immune response. The bad news is that because the cultured skin
doesn't have blood vessels, it can't respond to oral
antibiotics given to the patient to manage infections.
To get around the problem, doctors usually wrap the wound in
dressings soaked in antimicrobial drugs. But the practice is not a guarantee
against infection and it can contribute to the emergence of
drug-resistant bacteria.
Instead of fighting infection from the outside,
Supp and her team wanted to find a method that worked from the
inside — gene therapy.
They had read about a gene called HBD4, normally found in
other parts of the body, such as the male reproductive tract.
The gene is activated naturally when an
area becomes inflamed or in the presence of microorganisms. When
the gene turns on, it produces a protein that essentially pokes holes
in the cell membrane of the bacteria, killing it.
Supp and her team isolated HBD4 and transferred it to skin
cells. Next, they allowed the cells to divide and
multiply into a larger colony — each new cell containing HBD4.
Lastly, they exposed the genetically engineered cells to bacteria strains
common in hospitals.
