antigénkötést

Antigénkötés refers to the process by which an antigen binds to a specific antibody or a T-cell receptor. This interaction is fundamental to the adaptive immune system's ability to recognize and respond to foreign invaders, such as bacteria, viruses, and other pathogens. Antigens are typically molecules found on the surface of these invaders, or they can be soluble substances released by them. Antibodies, produced by B-cells, and T-cell receptors, found on T-cells, are proteins that have unique three-dimensional structures capable of recognizing and binding to specific antigenic determinants, also known as epitopes.

The binding is highly specific, akin to a lock and key mechanism. An epitope on the antigen fits into a complementary binding site on the antibody or T-cell receptor. This antigen-antibody or antigen-receptor complex formation triggers a cascade of immune responses. For antibodies, antigénkötés can lead to the neutralization of the pathogen, marking it for destruction by other immune cells, or activating the complement system. For T-cells, antigénkötés, often presented by antigen-presenting cells, signals the T-cell to initiate a targeted immune response, such as killing infected cells or helping to activate other immune cells. The study of antigénkötés is crucial in immunology, diagnostics, and the development of vaccines and therapeutic antibodies.