Today is World AIDS Day, and a good reminder of how far treatment of the disease has come. Back in the 1980s an AIDS diagnosis was equated with a death sentence. The following decades saw an advent in medications that prolonged the life span of patients stricken with the disease. Now scientists have used genetic engineering to develop red blood cells resistant to HIV, the virus that causes the disease. It’s a bold new approach ultimately aimed at finding a cure for AIDS.
As of yet scientists don’t know if this new approach will prove to be a cure, or even an effective treatment. What the research does show, however, is that a cure seems feasible.
Using a patient’s own blood to create immunity.Nearly four years ago in Berlin there was an astonishing case of an AIDS patient who seemed to recover after receiving donor blood cells from an individual who had a natural immunity to HIV. Researchers are hoping to see similar immunity using a patient’s own blood cells.
“For the first time, people are beginning to think about a cure as a real possibility,” said Dr. John Zaia, an expert in gene therapy. “Even if the new approach doesn’t get rid of HIV completely, it may repair patients’ immune systems so that they can control the virus and not need AIDS medicines.” This would be considered a “functional” cure.
A milestone in gene therapy. This is the first time researchers have permanently deleted a human gene and then reentered the altered cells back into patients. There have been other gene therapy attempts but they consisted up adding another gene or trying to restrict the activity of one. Neither of these attempts worked against the HIV virus.
There are some people who have a natural resistance to HIV, but they are rare. In the Berlin case, the HIV-resistant person donated blood stem cells to an American man who lived in Berlin and who was suffering from both leukemia and HIV. The red blood cell transplant cured both problems. However, finding suitable donors for everyone living with HIV is impossible, plus transplants are medically risky.
Scientists realized that if a patient’s own red blood cells could be used to delete the gene in question and create HIV resistance, then finding a cure could be a possibility. There is a biotechnology company in California capable of cutting DNA at precise locations and deleting the gene. In a new study, six men with HIV underwent such a gene snipping procedure. Three months later five of the six had as much as three times the number of modified cells as expected. As much as 6% of their T-cells appeared to be resistant to HIV.
While it may be overstated to suggest that these results indicate a cure, it is encouraging news for AIDS patients and their loved ones. And it is a huge step in the field of genetics.
