Since the outbreak of the new coronavirus pneumonia, the country has attached great importance to this epidemic prevention war, which is related to the lives and health of the people across the country, and organized a group of experienced infectious disease prevention and control experts to develop new coronavirus nucleic acid detection, antigen detection and other methods. I believe everyone is very familiar with nucleic acid testing, but what is antigen testing? To understand this problem, we must first understand what an antigen is.
Antigens refer to all substances that can activate and induce immune responses. They usually refer to substances that can be recognized and combined by specific antigen receptors (TCR or BCR) on the surface of T and B lymphocytes, activating T and B cell proliferation and differentiation, and producing immune response effects. Products (specific lymphocytes or antibodies) and combine with effector products to exert adaptive immune response effects. Theoretically, antigens can be all foreign and self-derived substances in nature, but the antigens usually recognized by the body's immune cells are proteins, including polysaccharides, lipids, and nucleic acids.
Not all foreign or self-substances are antigens. Substances with two important properties: immunogenicity and immunoreactivity are antigens. Immunogenicity refers to the ability of an antigen to be recognized and combined with specific antigen receptors (TCR or BCR) on the surface of T and B cells, inducing the body to produce an adaptive immune response; immunoreactivity refers to the antigen and the immune response effector substances it induces. (activated T/B cells or antibodies) specific binding ability.
The immune response induced by the antigen has antigen specificity, that is, the antigen stimulates the body to produce an adaptive immune response and its binding to the response effect product shows specificity. A specific antigen can only stimulate the body to produce activated T/B directed against that antigen. cells or antibodies, and can only specifically bind to the lymphocytes or antibodies. The specific binding characteristics of specific antigens to specific T cells or specific antibodies are the molecular basis of current immunological detection, diagnosis and treatment technologies.
T and B cells recognize antigens with high specificity through the specific antigen receptors (TCR/BCR) on their surfaces; the binding of T cells activated by antigens and the effector products of activated B cells, antibodies, to antigens is also highly specific. The molecular basis of the above two specificities depends on the antigenic epitopes contained in the antigen molecules, also known as antigenic determinants.
The novel coronavirus antigen test adopts a double-antibody sandwich method, which uses two antigen-specific antibodies to recognize and bind different epitopes of a target antigen. It can not only greatly reduce the chance of cross-reaction, but also has the characteristics of fast, accurate diagnosis, equipment and The advantage of low personnel requirements.
Not only does our country lead the world in new coronavirus detection methods, but the new coronavirus vaccine is also unique. For the health of ourselves and those around us, each of us should actively respond to the country’s call and get vaccinated against the new coronavirus in a timely manner!