Submit your comments on this article |
Science & Technology |
Avian Flu May Use White Blood Cells To Infect Internal Organs |
2008-11-10 |
One nasty (and usually fatal) consequence of infection with bird flu (influenza A/H5N1) in humans is that the virus doesn't just infect the lungs but becomes disseminated to many different organs. We know that a bird-like receptor that the virus can use to get into cells is found in several other organs, including the lining of blood vessels and neural tissues. Central nervous system involvement is frequently a hallmark of fatal bird flu cases. The virus probably gets to a lot of other organs, as well. But how? An examination of the blood of a fatal case in a pregnant woman suggests answer -- white blood cells:
What this means is that viral proteins and viral genetic material was found inside the kind of white blood cells (neutrophils) that make up the majority of white cells in our blood and that constitute the vanguard of our innate (non-specific) immune response. The neutrophils are like wandering policemen, engulfing foreign particles, bacteria, viruses and whatnot, and digesting them so they are no longer harmful. In this case it seems they have somehow internalized H5N1 virus, either by their normal "gobbling" process or because they have receptors on their surfaces that allow the virus to enter the cell and infect it. Once inside the neutrophil we don't know if the virus becomes disabled or remains infective. If the former, it may still cause the neutrophil to die, thus imparing the immune response, and if the latter, it may be the way the virus gets around the body, inside a cell and protected by antibodies in the serum. |
Posted by:Anonymoose |