A Body's Soldier
The body’s immune system is an extremely complex organization of various reactions which help to keep us healthy. Part of this system is a group of antibodies called immunoglobulins. These immunoglobulins have the job of recognizing antigens (invaders) and binding to them to aid in neutralization, or destruction. These invaders can be bacteria, viruses, fungi, or any microorganism that causes disease, mild or severe. There are five types of heavy chain immunoglobulins (IgM, IgG, IgA, IgD, IgE) and each of them cover different territories of the body and get called into action at different times for various reasons. One form of IgA called, secretory immunoglobulin A (SIgA), is found in the mucosal areas of the body and is the second most abundant immunoglobulin in our system. These mucosal areas include the gastrointestinal regions, the respiratory tract, and the genitourinary regions. It’s important that we have a defense system in mucosal areas because this mucus covers epithelial tissue (external and internal body surfaces) which acts as our first line of defense against pathogens.
Low IgA, or IgA deficiency, is reported as common and generally does not cause many health problems. However, high levels of IgA can cause many health issues including destruction of healthy tissues. This usually results in autoimmune disease, which is a disease where the immune system reacts to fight an intruder, but no intruder exists. These antibodies then attack healthy cells of the body by mistake. These high levels of IgA can be found in inflammatory diseases such as rheumatoid arthritis, celiac disease, inflammatory bowel disease (IBD), Sjogrens syndrome and many more. It is still unknown why this happens, but these conditions are thought to be genetic.
SIgA is dimeric (two identical molecules combined) in its structure. The two y-shaped IgA molecules bind to form an elongated, x-shaped SIgA molecule. The IgA molecules are bound with the help of a J-chain (joining chain) and the dimeric IgA molecule becomes SIgA with the addition of the secretory component (SC) molecule, which is pictured as the dark line wrapping around the SIgA molecule. The SC is what keeps the SIgA stuck in the mucosal areas so that it can go to work and do its job.
Dedicated to the strong women in my family who suffer from inflammatory autoimmune diseases.
https://doi.org/10.3389/fimmu.2019.00553
Abstract
Immunoglobulins have the job of recognizing antigens (invaders) and binding to them to aid in neutralization, or destruction. These invaders can be bacteria, viruses, fungi, or any microorganism that causes disease, mild or severe. One form of IgA called, secretory immunoglobulin A (SIgA), is found in the mucosal areas of the body and is the second most abundant immunoglobulin in our system. These mucosal areas include the gastrointestinal regions, the respiratory tract, and the genitourinary regions. High levels of IgA without pathogens present can cause many health issues including destruction of healthy tissues. This usually results in autoimmune disease.
A Body's Soldier
Immunoglobulins have the job of recognizing antigens (invaders) and binding to them to aid in neutralization, or destruction. These invaders can be bacteria, viruses, fungi, or any microorganism that causes disease, mild or severe. One form of IgA called, secretory immunoglobulin A (SIgA), is found in the mucosal areas of the body and is the second most abundant immunoglobulin in our system. These mucosal areas include the gastrointestinal regions, the respiratory tract, and the genitourinary regions. High levels of IgA without pathogens present can cause many health issues including destruction of healthy tissues. This usually results in autoimmune disease.