French Discover How AIDS Virus Enters Cells

French researchers said Monday they have discovered the gateway through which the AIDS virus penetrates and infects blood cells, a discovery that could lead to development of a vaccine to lock the virus out.

The Pasteur Institute team said it has discovered a “co-receptor” molecule, named CD26, used by all strains of the AIDS virus to gain entry.

AIDS researchers have known for several years that the human immunodeficiency virus latches onto a receptor molecule called CD4 on the surface of some blood cells.

“But we didn’t know how the virus got inside the cell to contaminate it,” said Dr. Ara Hovanessian, who headed the Pasteur research team. “Now we know that both the CD4 and the CD26 are necessary for the virus to penetrate and infect the cell,” Hovanessian said.

The CD26 structure was identified several years ago, but its function remained a mystery.

“In viral infections, the CD4 serves as the contact point for viral particles, while CD26 serves as the main door,” said a statement from the Pasteur Institute.

The group’s findings were to be presented today at an AIDS conference outside Paris.

AIDS researcher Robert Gallo of the National Institutes of Health in Bethesda, Md., said the findings appeared to be a “very exciting, very stimulating step” in AIDS research.

Pasteur Institute scientists say the discovery of a second receptor provides another avenue of research in developing a vaccine.

“The AIDS virus has always managed to have the key to open the CD4 receptor lock. We hope to be able to develop drugs capable of jamming the CD26 lock so that the AIDS key will no longer fit,” Hovanessian said.

Since every strain of the AIDS virus uses CD26 to infect cells, “we’re hoping to develop a universal vaccine,” he said.