Subject: Scientists Clone a Protein That Seems to Stop Spread of AIDS Virus
Date: Published: 12/18/87 86 lines
Source:  WALL STREET JOURNAL. Copyright Dow Jones & Co. Inc. 

    Genentech Scientists Clone a Protein
    That Seems to Stop Spread of AIDS Virus
    ---
    By Marilyn Chase
    Staff Reporter of The Wall Street Journal

    SOUTH SAN FRANCISCO, Calif. -- Scientists at Genentech
 Inc. said they cloned a natural protein that in the test tube
 appears to block infection by the virus that causes acquired
 immune deficiency syndrome, or AIDS. 
    The protein, called CD4, was produced in
 genetically-engineered mammalian cells and tested with the
 virus in cell culture, where it "virtually abolished the
 growth of HIV-1," the AIDS virus, scientists said.
    The work by Genentech research scientist Daniel J. Capon
 and colleagues is slated for publication today in the journal
 Science.  Other authors of the paper include Genentech
 scientists Douglas H. Smith, Scot A. Marsters, and Timothy
 Gregory in collaboration with Jerome E. Groopman and Randal
 A. Byrn of New England Deaconess Hospital in Boston.
    The substance still faces months to years of animal and
 human testing before any potential benefits to AIDS patients
 can be ascertained.  The Science paper is the first major
 scientific report on what is expected to be an important
 avenue of research into AIDS therapy.
    In its natural form, the protein normally is found on the
 outside of T4 cells, white blood cells that are key sentries
 of the immune system.  These cells are selectively targeted
 and killed by the fatal virus.  When the virus seeks out its
 targets, a protein on its outer coat binds to CD4 protein on
 the T4 cells -- a key step in infection.
    Scientists hope that injecting the synthetic CD4 molecules
 would flood the body with "false targets" to divert the virus
 and keep it from infecting whole healthy T4 cells.
    Genentech research scientist Daniel Capon said he believes
 CD4 works in several ways:  by blocking direct infection by
 free-floating virus; by preventing the formation of giant
 cells that foment cell-to-cell spread and mass cell death;
 and by preventing the immune system's turning against healthy
 T4 cells which aren't infected but have merely brushed up
 against the virus's outer coat and "look" infected.
    Still, he cautioned:  "I don't think this is going to be a
 cure.  It may contain the virus."  One problem scientists
 haven't solved is how to reach the virus as it lies latent
 inside infected cells.
    Genentech is one of several laboratories now developing
 CD4, along with researchers at SmithKline Beckman Corp.,
 Biogen, and Harvard University.  Earlier this week, SmithKline
 announced it was working on the substance as well.
    Richard Axel, a professor of biochemistry at Columbia
 University who is working with the SmithKline group,
 cautioned:  "We know too little about the patho-physiology of
 this disease to be overconfident.  I don't want to introduce
 false hopes."  He said his group and several others plan to
 publish their findings in the British journal Nature in about
 two weeks.
    Other investigators in the field of AIDS therapy voiced
 controlled optimism.  "I think it's a very interesting
 concept," said Samuel Broder, director of clinical oncology
 at the National Cancer Institute, a unit of the National
 Institutes of Health.  Dr. Broder, whose lab first discovered
 the efficacy of Burroughs-Wellcome Co. 's AZT, said he
 confirmed the test-tube activity of Genentech's CD4 as well.
    "What we're seeing here is the development of potential
 experimental agents based on what we know about the life
 cycle of the virus.  That's the kind of translation from
 laboratory to clinic that we need to encourage," Dr. Broder
 said.
    However, he and other scientists cautioned that because
 CD4 has a role in normal activities of the immune system,
 doctors will need to test the synthetic molecule for toxic
 effects -- namely any upset in immune function.  So far,
 however, test-tube studies don't suggest CD4 has great toxic
 potential.
    In national over-the-counter trading yesterday, Genentech
 shares closed at $37, down $1.50.

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