antigen - Definition & Meaning

any foreign substance in the body that can trigger a response from the immune systemany foreign substance in the body that can trigger a response from the immune system

An antigen is a foreign substance that triggers an immune response in the human body. It can be a molecule, such as a protein or a carbohydrate, that is recognized as non-self by the immune system. Antigens are often found on the surface of pathogens, such as bacteria or viruses, but can also be present on allergens or cells from transplanted organs. When the immune system encounters an antigen, it initiates an immune response to eliminate or neutralize it. This response involves the production of antibodies, activation of immune cells, and the development of immune memory. Antigens are crucial for the body's ability to distinguish between self and non-self and play a vital role in immune defense and disease recognition.An antigen is a foreign substance that triggers an immune response in the human body. It can be a molecule, such as a protein or a carbohydrate, that is recognized as non-self by the immune system. Antigens are often found on the surface of pathogens, such as bacteria or viruses, but can also be present on allergens or cells from transplanted organs. When the immune system encounters an antigen, it initiates an immune response to eliminate or neutralize it. This response involves the production of antibodies, activation of immune cells, and the development of immune memory. Antigens are crucial for the body's ability to distinguish between self and non-self and play a vital role in immune defense and disease recognition.

例句

The vaccine introduces a harmless antigen to stimulate immunity.
疫苗引入一种无害的抗原以刺激免疫力。
The blood test detects the presence of an antigen to diagnose infections.
血液检测检测抗原的存在以诊断感染。
Allergies occur when the immune system overreacts to a harmless antigen.
过敏发生在免疫系统对无害的抗原过度反应时。