Insight Into Hiv Cell Structure May Help Fight Aids

An individual human immunodeficiency virus’s attack on an individual cell of the immune system is the act from which flows all the devastation of AIDS.

The invasion begins when a virus attaches to a receptor on the cell’s membrane in a highly specific way. The virus’s envelope then melts into the cell’s membrane, disgorging the HIV genes. This infects the cell.

The details of these events-and what might be done to block them - are among the more intensely studied subjects in AIDS research. Last week, scientists at Massachusetts Institute of Technology’s Whitehead Institute reported new, and potentially useful, insights into the process.

The researchers, led by Peter S. Kim, determined the three-dimensional structure of a crucial part of gp41, a sugar-and-protein molecule that produces the actual fusion of virus and cell. Curiously, fragments of gp41 produced in the laboratory have the property of blocking cell-virus fusion. That fact, combined with the new understanding of gp41’s shape, raises the possibility that a drug might be designed to look like one of those fragments.