When a macrophage engulfs a foreign antigen, it phagocytizes it (or breaks it down) using enzymes. The fragments (called epitopes) of the original antigen are transported to the cell surface so that helper T-cells that specifically match the antigen can recognize it. When that happens, the helper-T cells are able to trigger a specific immune response to that exact antigen by stimulating more helper-T cells to be produced and by triggering B-cells to secrete antigen-specific antibodies that mark infected cells for destruction by killer T-cells.
Antigens are displayed on the surface of a macrophage after the digestion of a bacterium.
A macrophage is the type of cell that engulfs an invading pathogen through a process called phagocytosis. After engulfing the pathogen, the macrophage displays fragments of the pathogen's antigens on its cell surface to alert other immune cells to the presence of the invader.
Macrophages ( in the lymph nodes ) act like phagocytes to engulf and digest the pathogen. But they do not fully digest it. They separate out the antigens and incorporate them into a cell surface molecule. This is exposed on the surface of the macrophage, which becomes known as an antigen-presenting cell. Its function is to find the lymphocytes that can neutralise that particular antigen.
presents antigens of an engulfed pathogen in its class II MHC molecules to helper T cells, and releases IL-1
atoms
Blood antigens A and B are located on the surface of red blood cells, while the Rh antigen (Rh factor) is also found on the surface of red blood cells. These antigens determine an individual's blood type.
All cells produce antigens, or cell surface markers. The only question is whether the antigens are self antigens which means they belong in the body or they're foreign antigens which means they are an invading bacteria or virus (or a cancerous cell).
The ABO blood group antigens are located on the surface of red blood cells. These antigens determine an individual's blood type (A, B, AB, or O) and are inherited from their parents. The presence or absence of A and B antigens determines a person's blood type.
Antigens determining blood type are carried on the surface of red blood cells. These antigens are proteins or sugars that can trigger an immune response if they are not recognized by the body's immune system.
Blood type AB has both A and B antigens.
A person's blood type depends on the presence or absence of certain proteins called antigens on the surface of red blood cells. These antigens determine whether a person's blood type is A, B, AB, or O.
Antibodies primarily target extracellular antigens, which are found outside of cells. These antigens can be on the surface of pathogens or released into the extracellular environment. Intracellular antigens, located inside cells, are primarily targeted by T cells of the immune system.