Protein Able to Block AIDS Virus Produced

Scientists said Thursday they have developed a protein that can latch onto the AIDS virus, leaving it unable to infect human cells--at least in the test tube.

Scientists from Genentech Inc., of South San Francisco, and Harvard Medical School reported their findings about the substance, called “soluble CD4,” in the journal Science.

The soluble CD4 was produced through genetic engineering and is a modified version of a molecule found on the surface of human cells. It is the molecule or “receptor” that first receives the AIDS virus as it attacks important cells of the immune system.

Beaten in Announcement

The researchers were beaten in the announcement of their discovery by scientists at Smith Kline & French Laboratories of Philadelphia, who announced Wednesday they had made the same finding.

The Smith Kline announcement, however, was made in a newspaper, not a scientific journal.

The Genentech-Harvard group independently used genetic engineering techniques to work with a version of the human gene responsible for production of part of a protein called “CD4” present on the surface of human T-lymphocyte cells.

These white blood cells play an essential role in the body’s immune defenses and are the primary target of the AIDS virus as it spreads in an AIDS victim’s body. When a large proportion of these cells has been killed by the AIDS virus, the person is no longer able to fight off the opportunistic infections that ultimately kill most AIDS victims.