HIV's most important portal to infection, a cell surface molecule called CCR5, has been imaged at the atomic level, according to a study by a research team from China and San Diego. Knowledge of the structure can help in designing better HIV drugs.
CCR5 is the most commonly used of two "co-receptors" that strains of HIV, the virus the causes AIDS, used to attach to on immune cells. The other, CXCR4, has already been imaged.
The study was published Thursday in Science. It was performed by team including researchers from UC San Diego and The Scripps Research Institute. It complements another HIV study, published Thursday in the journal Immunology. That study examined how some HIV-positive people generate powerful broadly neutralizing antibodies to the virus.
HIV must bind to two receptors. One is the CD4 receptor, long known to be used by HIV. Researchers later discovered that a co-receptor was also needed.
Some anti-CCR5 drugs exist, but their mechanism of action is unknown. The study found the mechanism in one drug, called maraviroc, by examining it in combination with the CCR5 receptor.
About 10 percent of those European ancestry lack the CCR5 co-receptor on their immune cells. These people are nearly invulnerable to HIV infection. There is some evidence that this mutation is linked to hemorrhagic plague resistance.