Victory in the war on AIDS may be closer than ever before. Researchers have found a source for a chemical that may hold the key to ending the disease once and for all. A protein newly discovered in a kind of coral seems to have the ability to stop HIV from being infectious, meaning it can not only be incorporated into the treatment of people who are already HIV-positive, it can also help prevent the transmission of the virus, even without barrier protection.
Coral are often associated with coral reefs. The animals are invertebrates, and live in colonies; individual animals, called polyps, gather together with thousands of identical siblings. The most common and best known types form the exoskeletons that are the reefs. After decades or even centuries of growth—the coral reproduce by cloning, as well as sexually by releasing spores—these reefs can grow to enormous size. Other coral, known as soft coral, are lacy and flexible rather than stony, waving along with the current. Almost all coral get nutrients from a symbiotic relationship with algae that live among them.
Researchers identified the proteins, called cnidarin, while looking at specimens of feathery coral—a type of soft coral—collected near Australia. They then isolated and purified cnidarin and tested it against laboratory strains of HIV. The proteins were soon determined to be capable of blocking HIV at concentrations of a billionth of a gram. HIV transmission starts with the virus attaching itself to a type of immune cell known as the T-cell. Cnidarin blocked this attachment, defeating the virus. Uniquely the proteins bind to the virus, preventing it from getting into the T cell. This may help avoid the drug resistance that is the bane of HIV research; because its mechanism of action is unlike anything that has been seen before, it does not appear to contribute to resistance.
The next step, say researchers, is to find ways to produce more of the protein without over-harvesting the coral itself. They need to produce more cnidarin not only to meet demand if it does prove to be viable, but to determine if there are any side effects if there are any other illnesses against which the protein might prove useful, and to gain a more precise understanding of how it works, with an eye towards replicating the effect.