Scientists from the National Cancer Institute have discovered a protein found in sea coral that could potentially be used as a barrier for HIV (human immunodeficiency virus) transmission in sexual lubricants and gels.
If harnessed correctly, the protein would block HIV without also making the virus resistant to other HIV drugs, a common challenge in developing new treatment methods. The protein, found while screening thousands of natural product extracts in an NCI biological repository, was first discovered in the sea off the north coast of Australia. NCI researchers believe the proteins are ideal for inclusion in HIV-microbicides.
"It's always thrilling when you find a brand-new protein that nobody else has ever seen before,” said senior investigator Dr. Barry O'Keefe, according to Medical News Today. “And the fact that this protein appears to block HIV infection — and to do it in a completely new way — makes this truly exciting."
O’Keefe and his colleagues presented their findings at the Experimental Biology 2014 meeting in San Diego on April 29. The proteins derive from feathery coral, in the class called cnidarin. Though the specific mechanism is still unknown, researchers speculate the coral’s protein bind to the virus and prevent it from fusing to the membrane of the T cell. Without this contact, the virus can’t infect a host’s immune system, as T cells play a direct role in regulating the body’s immunity.
The protein behaves in a way that is "completely different from what we've seen with other proteins,” explained co-investigator Dr. Koreen Ramessar, an NCI research fellow. “So we think the cnidarin proteins have a unique mechanism of action." What the team doesn’t want to do, however, is mine the earth’s coral for protein development. Future research depends upon harvesting the protein in a lab, so it can be produced without stripping the planet’s natural supplies.
In this, O’Keefe credits the NCI repository for its contribution to the breakthrough, calling it a “national treasure” where "you never know what you might find."
Prior research into HIV prevention has yielded some noteworthy findings. Among those is the 2013 discovery that an intravaginal ring called TDF-IVR (tenofovir disoproxil fumarate intravaginal ring) can deliver a smaller dose of the antiretroviral drug tenofovir but at 1,000 times the quantity. Users keep the ring in place for up to 30 days, with transmission occurring at key times thanks to the polymer used to construct the ring.
"After 10 years of work, we have created an intravaginal ring that can prevent against multiple HIV exposures over an extended period of time, with consistent prevention levels throughout the menstrual cycle," Patrick Kiser, an expert in intravaginal drug delivery originally from the University of Utah, where the research was conducted, said in a statement.
Both treatment options are set to stabilize, and ultimately reduce, the number of people living with HIV/AIDS worldwide, which currently sits at 9.7 million. Of those, currently 3.5 million people take tenofovir orally as HIV therapy.