Welcome to the PGA TOUR career site! When most people think of the PGA TOUR, they envision famous golfers, exciting tournaments, and the TOURâs generous support of more than 3,000 charities. We are all of these things, but thereâs much more to the PGA TOUR than meets the eye.
An antigen is a substance that enters the body and stimulates the production of an antibody to fight what the immune system perceives as an invader. Antigens can be toxins, bacteria, foreign blood cells and the cells of transplanted organs. Other antigens, called autoantigens, or self-antigens, are usually normal proteins in the body that are targeted by the immune system of lupus patients as foreign bodies. 1  In other words, normal tolerance of these autoantigens has been lost in lupus patients, mainly to genetic and environmental factors.
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shape protein produced by plasma cells that is used by the immune system to identify and neutralize pathogens such as bacteria and viruses. The antibody recognizes a unique molecule of the harmful agent, called an antigen, via the variable region.his region is known as the hypervariable region. Each of these variants can bind to a different antigen. This enormous diversity of antibody paratopes on the antigen-binding fragments allows the immune system to recognize an equally wide variety of antigens.