AUGUSTA, Ga. The future of organ transplantation could include microscopic beads that create "designer" immune cells to help patients tolerate their new organ, Medical College of Georgia researchers say.
"It's absolutely natural," says Dr. Anatolij Horuzsko, reproductive immunologist at the MCG Center for Molecular Chaperone/Radiobiology and Cancer Virology, who has used the approach successfully in mice with skin grafts.
The degradable microparticles deliver the most powerful known form of HLA-G, a natural suppressor of the immune response, straight to dendritic cells, which typically show the immune system what to attack. The microparticles are given right after a transplant, just as dendritic cells are giving the immune system a heads up to get busy attacking the new organ.
Microparticle therapy likely would be needed for just a few weeks, until the dendritic cells have learned instead to ignore it, Dr. Horuzsko says. "It's like a calming effect and once tolerance is established, we don't need it any more."
His lab reported its success with this delivery method in mice with skin grafts last month in Human Immunology. When researchers compared the success of HLA-G microparticles with the dendritic cell marker to those without a marker, those with were much more efficient at getting where needed and acting, he says. Those without direction likely were consumed by garbage eaters called macrophages.
Unlike current anti-rejection drugs that generally suppress the immune system leaving patients vulnerable to infections, cancer and more HLA-G offers specific "tolerance." Fetuses, which also use the compound to escape rejection by the mother's immune system, are good examples of the specific tolerance HLA-G affords, Dr. Horuzsko says.
"We want to create in kidney transplant patients, the same tolerance to the new kidney." Within five years, HLA-G microparticles could be doing just that, Dr. Horuzsko says. He
|Contact: Toni Baker|
Medical College of Georgia