ScienceDaily: — Researchers at the Institut Pasteur and CNRS have shown for the first time that certain viruses are capable of forming complex biofilm-like assemblies, similar to bacterial biofilms. These extracellular infectious structures may protect viruses from the immune system and enable them to spread efficiently from cell to cell. "Viral biofilms" would appear to be a major mechanism of propagation for certain viruses. They are therefore emerging as new and particularly attractive therapeutic targets.
The HTLV-1 virus (human T-cell leukemia virus type 1) was the first human retrovirus to be isolated, in 1980, three years prior to the discovery of HIV, the retrovirus that causes AIDS.
It infects 15 to 20 million people worldwide and causes various diseases, ranging from adult T-cell leukemia/lymphoma to forms of neuromyelopathy (tropical spastic paraparesis) or other chronic inflammatory syndromes, such as infectious dermatitis, uveitis and myositis. The dissemination of HTLV-1 was known to require infected cells and cell-cell contacts, but the transmission mechanism itself was still a mystery.
In the biofilm -- an effective protective and adhesive barrier -- HTLV-1 is far more easily transmitted than in its free, isolated state. By removing the viral biofilm from the surface of the infected cells, researchers achieved an 80% reduction in infection rates, thus underlining the importance of this transmission mode for HTLV-1.
In bacteria, the existence of biofilms has been known for many years. They form the dental plaque on the enamel surface of teeth and ... Read more>>