Last week I wrote about a recent paper showing that in some cases influenza viruses can escape from the lungs of an infected person; here, it makes it's way to the local lymph nodes by infecting your lung's sentinal immune cells, the dendritic cells. In this instance, this mechanism is probably being used by our own body's as a defence: by capturing influenza virus in the lung we can kick start our immune system by handing it directly to T and B cells within the lymph nodes. But it can also have deadly implication, especially considering that possibly every virus will have some run in with a dendritic cell during an infection.
**for a great discussion of what goes on inside lymph nodes during the induction of an immune response, see last weeks This Week in Virology**
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| Complicated diagram of the role of dendritic cells in the immune response. On the left, DC's grab antigen (for example a virus) and thus move into nearby lymph nodes. Here they present antigen to T cells ( or B cells). These cells leave the lymph nodes to hunt down their specific antigenic target (shown on the right here whether the T cells move into infected tissues. What DC's can also do is carry infectious viruses into the lymph nodes where they are free to replicate inside the dense population of T and B cells. http://www.biken.osaka-u.ac.jp/COE/eng/project/images/fig-hirata-jpg.jpg |