Blocking Viruses From Entering Cells

Defensins, first discovered more than 20 years ago, are peptides naturally produced by the immune system to fight off viruses. However, until now, it has not been known just how defensins worked. Now, scientists have found that a specific defensin called retrocyclin-2 (RC2) attaches to carbohydrate-containing proteins in cell membranes.

This process constructs molecular barricades that block attacking viruses from entering and infecting the cell. RC2 stops the virus immediately, preventing it from replicating and spreading throughout the body.

The researchers, from the U.S National Institutes of Health (Bethesda, MD, USA) and the University of California, Los Angeles (USA), utilized human and animal cell lines to demonstrate RC2's protection against the influenza virus. The group's previous studies suggest that RC2 provides great potential as a major compound for new antiviral drugs to combat HIV and herpes, as well. Unlike antibodies, however, defensins are not pathogen-specific. In addition to blocking viruses, RC2 also kills several bacteria that are highly resistant to conventional antibiotics.

The study was published in the September 11, 2005, online issue of the journal Nature Immunology.




Related Links:
National Institutes of Health
University of California, Los Angeles