Attacking HIV Through Protective Capsule

HIV infection may be able to be blocked by attacking the protective capsule of the virus called the capsid, according to a recent study.

Published on December 15, 2014, in Proceedings of the National Academy of Sciences, the study examined the vital role played by the capsid, which surrounds the HIV-1 genome. To release its disease-causing contents at the right time and place, the capsid must disassemble when the virus enters the cell.

“It’s still a matter of debate at what point the capsid falls apart in HIV-1 infection of cells,” senior author Dmitri Ivanov, PhD, said in a press release.

The study indicates how HIV inhibitor PF74 and the host protein CPSF6 bind to the capsid surface in a small pocket to block it from disassembling. As a result of this process, the viral information is kept inside. “We think that this process can be targeted for therapeutic purposes in HIV-1 infections,” Dr. Ivanov said.

The researchers utilized X-ray crystallography in order to examine the 3-dimensional structure of the CPSF6 protein that binds to the capsid.

“Seeing molecules in 3-D is illuminating; it tells us something about their function,” Dr. Ivanov said. “We now know how PF74 and CPSF6 interact with the adjacent building blocks of the HIV-1 capsid, thus stabilizing the entire capsid structure. It tells us that these molecules bind to the capsid before disassembly, blocking viral replication.”