Final answer:
The immune system distinguishes self-antigens from non-self antigens through a process called immune tolerance where T and B cells learn to recognize and not attack the body's own cells, preventing autoimmune diseases. Non-self antigens, such as those from pathogens, trigger immune responses. Major histocompatibility complex (MHC) molecules assist T cells in this differentiation.
Step-by-step explanation:
How the Immune System Differentiates Self from Non-Self Antigens
The human immune system has the critical role of protecting the body against pathogens. A vital part of this defense system is the ability to differentiate between self-antigens and non-self antigens. This distinction is crucial because it prevents the immune system from attacking the body's own cells, which could lead to autoimmune diseases.
Self-antigens are molecules produced by the body's cells and are typically ignored by the immune system. The cells of the adaptive immune system, such as T and B cells, go through a process during their maturation where they learn to recognize these self-antigens and avoid attacking them. This process of learning is called immune tolerance and is essential for preventing the immune response from being directed against the body's own tissues.
In contrast, non-self antigens, which are often found on the surfaces of pathogens such as viruses and bacteria, trigger an immune response. The immune system generates specific antibodies via B cells or activates T cells that seek out and destroy cells presenting these foreign antigens.