There are cells in mucosal surfaces responsible for initiating the response when injure starts. They behave like gossip reporters when something wrong happens. When there is exposure to antigens, for instance, these cells engulf the substance an run away to present most of the constituents of the original antigen to the army of natural defenders.
A network of alarms
These cells have been originally called Langerhan Cells. According to Tsoumakidou M and cols. (Am J Resp Crit Care Med 2008. 177:1180-1186) this group of cells are the Dendritic Cells. Dendritic Cells include three subsets: type 1 myeloid, type 2 myeloid, and plasmocitoid. Their origin is not at the lungs, however it is still under debate.
The migratory informers/spies
Those cells are relocated to the lungs by the circulating blood. Once in the lungs, dendritic cells settle down and wait for signals of danger like fish in submarine caves.
Thy are activated when find an antigen, which is engulfed and immediately drained from the area where it was caught. Dendritic Cells migrate to the lymph nodes and during the new relocation the mature expresing in their surface new markers like their uniform abandoning their camouflage and carrying some amounts of antigen.
Once in the lymph nodes, dendritic cells may induce tolerance or T-cell and B-cell responses which depends on how harmfull the antigen is.
Cigarette smoking and Dendritic Cells
How much are our gossip journalists (officially dendritic cells) involved in the reaction to cigarette smoke has not been clarified completely.
In the article by Tsoumakidou, they present a list of effects due to cigarette smoke on dendritic cells. Some studies have demosntrated that exposure to nicotine, cigarette smoke extract, as well as to lung secretions alter their functionality leading to a disarray in the orchestra conducting function.
Other studies have shown that dendritic cell’s function is also altered in experimental mice models of emphysema.
Hypothesis Tsoumakidou of dendritic cellsinvolvement in COPD
Then, the hypothesis of Tsoumakidou is that the long term exposure of dendritic cells to cigarette smoke may be related to the disorder seen in patients with COPD. This situation is manifested through repeated exacerbations, as well as local infections, and the exaggerated inflammatory response seen in this “progressive chronic disease“.
Cigarette Smoking doesn’t help in this life
Although there’s more light in the understansding of COPD, there’s no doubt on the complexity of the cellular environment of this condition and how cigarette smoke really doesn’t help to make it better.