NIAID Researchers Identify Second Fusion Cofactor for HIV

06/14/96 14:48 IEDIATEL FAX SERVICE->SCIENCE (FREELANCE)/JON COHEN 881
JUN-14-1996 17:28 NIAID 301 402 0120 P.02
Office of
SNIAID Comunications
National institute of Allergy and infectious Diseases * National Institutes of Health
EMBARGOED FOR RELEASE Greg Folkers
Wednesday, June 19, 1996 [phone]
4:00 p.m. Eastern Time [email protected]
NIAID Researchers Identify Second Fusion Cofactor for HIV
Researchers from two collaborating laboratories at the National Institute of Allergy and
Infectious Diseases (NIAID) have found that the strains of HIV most often transmitted from
person-to-person require a cell surface molecule called CC CKR5, in addition to the primary
receptor, the CD4 molecule, in order to fuse with the membranes of immune system cells.
Fusion is an integral step in the process whereby HIV enters cells.
The current report, from the laboratories of Edward A. Berger, Ph.D., and Philip M.
Murphy, M.D., will appear in the June 28, 1996 Science. The paper complements a recent
NIAID study that identified another fusion cofactor -- fusin -- used by other strains of HIV for
entry into immune cells (see Science May 10, 1996). "These and related studies show the
rapid progress that can be made with a continuing investment in basic research," says
Department of Health and Human Services Secretary Donna E. Shalala. "The science is
moving rapidly, providing potential new targets for the development of drugs and other
interventions."
The editors of Science have moved the embargo date and time of the current paper
forward, to Wednesday. June 19 at 4:00 p.m. ET, to coincide with the publication of two related
papers by independent groups in the June 20 Nature.
In their experiments, the NIAID investigators found that "macrophage-tropic" isolates of

HIV-1 fused readily with cells that have both CD4 and CC CKRS on their surfaces, whereas the
same viral isolates failed to fuse with cells expressing only CD4. Macrophage-tropic isolates of
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