BioWorld International Correspondent

PARIS - Euroscreen SA signed a licensing agreement with Pfizer Inc. that gives Pfizer access to the Belgian company's patent rights covering CCR5, a specific G protein-coupled receptor. Financial terms of the deal were not disclosed.

Pfizer, of New York, is one of a number of pharmaceutical companies exploring the potential of the CCR5 receptor as a key target for anti-HIV therapies. CCR5 is a chemokine receptor that is found on the surface of T cells and plays a central role in the mechanism by which HIV binds to and enters white blood cells.

The CCR protein binds chemokines (naturally produced small molecules), which act as chemical attractants to recruit immune cells to sites of inflammation. However, in the process of HIV infection, CCR5 acts as a crucial co-receptor to CD4 (the primary docking site of the virus) to allow HIV not just to bind to T cells but also to fuse with the cell membrane. Fusion of HIV to the T-cell membrane enables the viral genetic material to enter the cell and integrate with the host's genome, but that process does not occur in people who express the delta-32 CCR5 gene.

Brussels-based Euroscreen's patent is the first to establish a direct role of the CCR5 receptor in HIV infection. The company is specialized in research into GPCRs, cell membrane proteins that are known to be potential therapeutic targets in many disease areas. Using its high-throughput AequoScreen cellular assay platform to identify new activators (or ligands) of GPCRs that have therapeutic potential, it produces recombinant cell lines and membrane preparations, as well as providing screening and cloning services.

The company is building a patented portfolio of GPCR targets and drug leads for licensing to the biopharmaceutical industry, and has concluded licensing or collaboration agreements with several companies.