As of 2007, 33 million people were infected with HIV internationally, according to AVERT, an international HIV and AIDS charity. For decades, researchers around the globe have been working to alleviate this annually growing number of people infected with the disease.
Today, Penn researchers are working on innovative ways of preventing and coping with HIV, a lentivirus - a virus with a long incubation period - that commonly leads to AIDS.
David Weiner, a professor in the Department of Pathology and Laboratory Medicine, is helping to develop PENNVAX, a new DNA vaccine for HIV, which is currently undergoing clinical trials at Penn as well as Drexel University.
Traditionally, vaccines are either "live" - more immunologically effective - or "dead." Live vaccines produce antibodies, stimulate cytotoxic T-cells (CTLs) - white blood cells that kill infected somatic or tumor cells - and induce lifelong immunity, while "dead" vaccines only form antibodies, rendering them less effective and giving them the potential to fade over time, Weiner explained.
However, dead vaccines, in their inability to change over time, are safer, he added.
DNA vaccines are a relatively new concept which use pure genetic material that has been engineered and inserted into an individual's cells. These cells are altered at a molecular level to produce antibodies and CTLs, creating a response almost equal to that of a live vaccine but with the safety of a dead one.
They are considered safer because they are "non-live, non-replicating and nonspreading," Weiner said.
"The most important thing right now is it appears to be very safe," he said, though his long-term goal is to make this vaccine produce the same immunogenic response as a live virus.
There is a possibility that if the DNA vaccine works against HIV, the same technology may be extrapolated to use against some kinds of cancer.
Meanwhile, other researchers on campus along with Adaptimmune, a company that uses T-cell therapy to treat cancer and infectious diseases, are experimenting with another way to control HIV with gene therapy.
In gene therapy, cells are removed from a body and genetically engineered to have a better ability to recognize HIV, which should allow the cells to be more effective in fighting the virus, Pathology and Laboratory Medicine professor Jim Riley said.
"The hope is that the cells that are put in will kill the infected cells, and then the patient will be able to control their virus in the absence of an anti-retroviral," he explained.
Gene therapy will be tested first for people who are already infected with HIV.
"Once you're infected with HIV, it is very hard to actually get rid of it," said Pathology professor Carl June, who is working with Riley. "But what you can do is prevent it from dividing and replicating."
