Prior to studying the lymphatic system today, I admittedly knew very little about immunity. Although I knew it helped to prevent sickness and illness and fought against pathogens, I knew very little about how it was able to do these things. While we learned many things about the system for this week, I personally found the concept of self-recognition and self-tolerance in relation to autoimmunity to be quite fascinating.
When considering one's body, you'd naturally think that each and every part of it is built to support you; to support your living. That's why learning that one's own cells (T cells, to be exact) and immune system can work against the body and attack your own cellular tissues was both surprising and a little scary. Of course, body parts can and do malfunction throughout your life, but I'd never thought about the possibility of your own body actively hurting you.
In simple terms, your body's T-cells are usually able to recognize your own MHC proteins (self-recognition) and do not react to peptide fragments from your own proteins (self-tolerance). So while T-cells normally produce antibodies to help create "killer cells" (cells that attack specific antigens/foreign bodies), T-cells would be "programmed" to avoid attacking your own body's cells. However, the malfunctioning of this trait causes autoimmunity, wherein the immune system fails in self-recognizing and/or self-tolerating, thus attacking the body's own tissues.
One example of this would be diabetes, which I hadn't known to be an autoimmune disease. Here, T cells attack pancreatic cells that produce insulin. Diabetes is a condition wherein the body doesn't make enough insulin in comparison to the amount of blood sugar in your bloodstream, causing sugar levels to stay high and later causing serious health issues. I personally find this to be very important in my life as my family does have a history of diabetes, and I've always been warned about it ever since I was young. Knowing about how autoimmune diseases such as this work and how they can manifest may help me in trying to prevent them through healthier lifestyles, as well as possibly recognizing the signs of illness if I or other family members were to contract it in the future.