Coral reefs are raising hope in the global fight against the spread of AIDS and HIV. They may provide a tool for blocking the virus.
Researchers have found a new class of proteins in coral reefs that can block the HIV virus from penetrating T-cells. The discovery is creating excitement and raising hopes that it can be used to develop a way to stop the spread. For example, there is a hope that the protein can be used in sexual lubricants or gels that will act as a barrier against HIV, eliminating the need to rely on condoms.
The proteins found in the coral reefs off Australia’s northern coast is called cnidarins. The researchers honed in on the protein while screening thousands of natural product extracts in a bio-repository maintained by the National Cancer Institute.
The senior investigator, Barry O’Keefe, Ph.D., who is the Molecular Targets Lab deputy chief in the cancer research center at the National Cancer Institute, acknowledged how thrilling it was to find a new protein that had not been seen before. He added that finding that the protein from coral reefs actually seems to block HIV infection makes its truly exciting, while raising hope of a way to fight HIV and AIDS infections.
The scientists discovered the cnidarins while screening for proteins, which have been an understudied component of the extract repository. The National Cancer Institute maintains a collection of specimens gathered from around the world and available to researchers across the U.S.
The research team identified the cnidarin proteins and purified them. They then tested the proteins’ activity against HIV laboratory strains. They found that the proteins were astonishingly effective at blocking HIV at concentrations of a billionth of a gram. They prevented the first step in HIV transmission, where the virus enters the T-cell type of immune cell.
The study showed the cnidarins would bind to the virus, thereby preventing it from fusing with the T-cell membrane, according to team member Koreen Ramessar, Ph.D., a postdoctoral research fellow at the National Cancer Institute. The reaction was completely different from what the group saw with other proteins, “so we think the cnidarin proteins have a unique mechanism of action,” she noted. Ramessar presented the findings during the annual Experimental Biology 2014 meeting yesterday in San Diego.
Given the limited coral supply, the researchers acknowledge that their next step will be developing methods for generating cnidarins in large quantities. They need an adequate supply of the protein to test further and identify potential side effects and test the protein against other viruses to see if it protects against them too. “Making more of it is a big key,” said O’Keefe. To avoid stripping the ocean of coral in an effort to harvest the protein, he noted that their primary focus now have to be finding ways to produce more so they can proceed with preclinical testing.
O’Keefe called the repository of natural product extracts a national treasure. He noted that scientists using it never know what they might find. With the excitement over the progress in the HIV/AIDS fight, O’Keefe raised the hope that discoveries like this coral reefs protein “will encourage more investigators to use this resource to identify (other) extracts with activity against infectious disease.”
By Dyanne Weiss