The Gut’s Mucosal Immune System
Peculiar fact-of-the-day, the name “epithelia” was coined by Frederik Ruysch from the Greek “epi” (on top) and thēlē (nipple) based on features he discovered in lip tissue.
Epithelium is the type of tissue that lines many surfaces of the body, including the skin, blood vessels, respiratory tract, and the gastrointestinal tract. In the gut, this layer of closely-fitted cells, comprising several different types, provide a physical barrier and a variety of secreted substances. Some of these cells, like Paneth cells, release antimicrobial proteins that act against pathogenic microbes. Others, called goblet cells, secrete proteins called mucins, that form the mucosal layer lining the gut.
The mucosal immune system (yes, we finally got there), comprises the biochemical and cellular components that work to protect the gut epithelium (and other mucosal epithelia, like that in the lungs) from direct contact with bacteria. Like the peripheral lymph nodes and spleen that protect the tissues and blood, the mucosal immune system contains T-cell receptors, B-cell-derived antibodies, and other key components of the adaptive and innate immune systems.
Tune in in a few weeks for the next #gutscience by #SmartHerbals instalment about (among other topics) the critical role our microbial passengers play in keeping the mucosal immune system running!
#sciencefacts #colonhealth #SmartBiotech
sources: Bevins CL and Salzman NH. (2011) Nature Review Microbiology 9:356–368. Bischoff, SC. (2011) BMC Medicine 9: 24. MacCord, K. (2012) Embryo Project Encyclopedia. McGhee JR and Fujihashi K. (2012) PLoS Biology 10: e1001397.
Image adapted from Adobe Stock - SciePro
Bonus content
For the word nerds – “immune” has the same Latin root (munus) as “mean” (synonymous with “humble”), arriving at “service” by way of “common”. Quite a roundabout way to get to the idea of someone being exempt from service (probably taxes) and from there to protected from disease!
