Title/Topic:	FRENCH SCIENTISTS FIND ``KEY'' USED BY AIDS VIRUS
Source:   	RTw  10/25/93 5:29 PM 
Author:	Jeffrey Herwatt
Date:	06:38 PM Today

               
  Copied without permission from the Washington Post  ( 10/25/93 )

    By Claire Rosemberg
     PARIS, Oct 26 (Reuter) - French scientists who discovered how the AIDS 
virus penetrates body cells have made a major breakthrough opening the way to a 
possible vaccine, Luc Montagnier, the discoverer of the deadly virus said on 
Tuesday.
     "This is a very important step," Montagnier said on the Antenne-2 
television network. "It explains how the virus can enter once it has hooked 
upon another receptor."
     "This will lead to other applications as regards treatment and a vaccine. 
The vaccine could be of universal value," he said.
     Scientists from France's Pasteur Institute said on Monday they had found a 
new molecule which helps the HIV virus infect human cells.
     Dr Ara Hovanessian, head of Pasteur's department of virology and cellular 
immunology, said his research team had isolated a co-receptor, labelled CD 26, 
which works along with the known receptor CD4 in allowing the Human 
Immunodeficiency Virus (HIV) to invade a healthy cell.
     While CD4 allows HIV to hook on to cells, CD26, a protease also called 
dipeptidyl peptidase IV, acts as a door allowing the virus to penetrate the 
cell.
     "We have identified this door," Hovanessian said. "Like all doors it has a 
lock. The virus therefore uses a key to open the lock to enable it to penetrate 
cells."
     "If we manage to develop vaccines against these keys," he told Antenne-2, 
"we will have vaccines against different types and sub-types of the infection."
     A team has already begun experimenting on mice, medical sources said.
     The institute said in a statement the discovery of CD26's major role in 
the mechanism allowing the virus to penetrate and infect cells "opens new 
prospects in the research of therapeutic agents and vaccines" in the fight 
against Acquired Immune Deficiency Syndrome.
     Until the Pasteur discovery, CD4, discovered in 1984, was the only 
receptor known to AIDS researchers. But scientists had suspected for several 
years that another co-receptor existed.
     One of the most stubborn obstacles to producing an effective AIDS vaccine 
has been the unknown number of strains of HIV.
     Until now, a vaccine that stimulated anti-bodies against all strains of 
the virus to protect against AIDS appeared to be the only option.