Answer: Antibodies are produced by the immune system to neutralize foreign substances (antigens) that enter the body, including antigens found on red blood cells (RBCs). When the body encounters an antigen for the first time, it takes some time for the immune system to respond and produce specific antibodies. This process is known as the primary immune response.
Here's how the primary immune response works:
Recognition of antigens: The immune system recognizes antigens on the surface of RBCs as foreign and triggers an immune response.
Activation of immune cells: Immune cells, such as B-cells, are activated and begin to produce and secrete antibodies that specifically target the antigens on RBCs.
Clonal expansion: The activated B-cells multiply and differentiate into plasma cells that produce large amounts of antibodies.
Antibody production: The plasma cells produce and secrete antibodies, also known as immunoglobulins, that have a specific shape and structure that allows them to bind to the antigens on RBCs.
Destruction of antigens: The antibodies bind to the antigens on RBCs and mark them for destruction by other immune cells.
In subsequent exposures to the same antigens, the immune system is able to respond more quickly, producing a secondary immune response that is much faster and more effective in neutralizing the antigens. This is why, after a person is exposed to a pathogen for the first time, they are typically immune to it for a certain period of time.
In conclusion, a person produces antibodies against the antigens found on their RBCs through a process of activation and clonal expansion of immune cells, leading to the production and secretion of specific antibodies.