Can Viruses Form Biofilms and Scar Tissue?
There has been a lot of recent research about bacteria’s ability to form protective biofilm shields and cysts. Seeing how and why bacteria forms these colonies, it seems very sensible that chronic virus diseases may also take advantage of biofilm protection.
However, the virus / biofilm connection have not been very well researched yet. One difficulty is that this type of virus research usually requires an electron microscope that many facilities can’t afford. Another is simply that biofilms are a relatively new area of research and interest hasn’t focused on the virus aspect yet.
However, any chronic viral condition, such as HIV, Herpes (Shingles), and Hepatitis, are worth considering – especially if the condition produces inflammation!
The most often referred to study is one by researchers at the Institut Pasteur and CNRS. It showed, for the first time, that certain viruses appear to be capable of forming complex biofilm-like assemblies – similar to bacterial biofilms! These extracellular biofilm structures may protect viruses from the immune system and enable them to spread efficiently from cell to cell.(1)
They maintain that “viral biofilms” would appear to be a major mechanism of propagation for certain viruses. Viruse biofilms 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. 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 recent finding that the human T-cell leukemia virus type 1 (HTLV-1) encases itself in a carbohydrate-rich adhesive extracellular “cocoon” (a type of biofilm). This enables its efficient and protected transfer between cells and unveiled a new infectious entity and a novel mechanism of viral transmission.
These HTLV-1 structures are observed at the surface of T cells from HTLV-1-infected patients and are said to be reminiscent of bacterial biofilms. In fact, it is proposed that, similar to bacterial biofilms, viral biofilms could represent “viral communities” (would that be worth calling a “viral-film” vs bio-film???). These have enhanced infectious capacity and improved spread compared with ‘free’ viral particles, and might constitute a key reservoir for chronic infections.(2)
An Epstein-Barr Example
An example of viral biofilm possibilities also happened when Dr. Jose Montoya, an infectious disease specialist at Stanford University, released preliminary findings. They were a double-blind placebo-controlled antiviral trial of Valcyte for a subset of patients displaying high antibody levels to human Herpes Epstein-Barr HHV-6 and EBV virus.
“Causes of many chronic diseases
are unknown and chronic viral infection
is one of the most suspected candidates!”
This was from Dr. Kondo, who spent 20 years trying to identify the latent protein responsible for chronic CNS disease and mood disorders. Healthy patients showed no evidence of this protein. HHV-6 and/or Epstein Barr Virus can cause Chronic Fatigue Syndrome and treating biofilms may be part of the answer.(3)
The mechanism underlying the inhibition of biofilms by GV is unknown. However, in addition to host immune status, candida might be one example of this symbiosis of biofilms and viurses.(4) Candida biofilms, of course, are resistant to commonly used antifungals. This can provide a protective hiding place for something like HIV and is believed to be a key determinant of this disease.(5)
Link to more Biofilm Information.
1. Maria-Isabel Thoulouze and Andrés Alcover. Institut Pasteur, Department of Immunology, Paris, France. 2 CNRS-URA-1961, F-75724.
2. Trends Microbiol. 2011 Jun;19(6):257-62. doi: 10.1016/j.tim.2011.03.002. Epub 2011 Mar 31.
3. Biofilms and Chronic Infections. JAMA June 11, 2008. P 2682-3 and Science 2000; 289:1754-1757.
4. Tirwomwe J. F., Rwenyonyi C. M., Muwazi L. M., Besigye B., Mboli F. 2007. Oral manifestations of HIV/AIDS in clients attending TASO clinics in Uganda. Clin. Oral Invest. 11:289–292.
5. Traboulsi R. S., Mukherjee P. K., Ghannoum M. A.. 2008. In vitro activity of inexpensive topical alternatives against Candida species isolated from the oral cavity of HIV-infected patients. Int. J. Antimicrob. Agents 31:272–276.
Also: Thompson G. R. III, et al. 2010. Oropharyngeal candidiasis in the era of antiretroviral therapy. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 109:488–495.