Reports for NATAP

AIDS Vaccine 2001 Conference

September 6, 2001 Philadelphia, PA

New HIV Treatment And Vaccine Candidates Identified

WESTPORT, Mar 06 (Reuters Health) - A naturally occurring modification to the HIV-1 coreceptor CCR5, which inhibits viral binding to the cell surface, has been identified by researchers at Progenics Pharmaceuticals, Inc. This finding "may have broad implications for the design and development of drugs that target CCR5," according to a statement issued by the Tarrytown, New York-based company.

When the researchers examined the in vitro effects of synthetic CCR5 peptides, which were modified by adding sulfate groups to specific amino acids of CCR5, they found that HIV-1 binding to CCR5 was blocked.

"These new findings pinpoint the CCR5 structures that HIV recognizes during infection of target cells," according to Dr. Tatjana Dragic of Albert Einstein College of Medicine in New York City. "The discovery is important both for our understanding of AIDS pathogenesis and for the design and development of CCR5-targeted fusion inhibitors," Dr. Dragic told participants at the Keystone Symposium on Cell Biology of Virus Entry, Replication and Pathogenesis in Taos, New Mexico.

These data and those from previous studies "significantly enhance our technology base in the CCR5 fusion area," Ronald J. Prentki, President of Progenics, said. "The findings are important for our existing CCR5 antibody and small-molecule drug programs, and may ultimately lead to the development of an important new class of HIV fusion inhibitors."

Elsewhere, researchers at Cel-Sci Corporation announced that they have identified a novel HIV vaccine candidate. The HIV vaccine would be used to stimulate an immune response in HIV-infected patients who are also on antiretroviral therapy, officials at the Vienna, Virginia, company explained.

The new HIV vaccine candidate was developed using Cel-Sci's T-cell modulation platform technology, Ligand Epitope Antigen Presentation System (L.E.A.P.S.), in combination with an HIV epitope located at the core of the virus.

"This epitope represents a region of HIV that is less subject to mutation, thereby hopefully reducing or eliminating the virus' chance to escape control by the immune system through mutation," according to Dr. Daniel Zimmerman, Senior Vice President of Research at Cel-Sci. "This epitope is an improved version of Cel-Sci's HGP-30 epitope that has already been tested in about 100 volunteers, mostly as a preventive vaccine."

The researchers hope to create a vaccine that induces "a strong cellular immune response against HIV similar to that seen in 'long-term non-progressors' who...have maintained a disease-free status for many years, even without treatment."

The website for the Vaccine Conference is:
http://www.AIDSvaccine2001.org