T cell receptor

A T cell receptor is a protein found on the surface of immune cells called T cells that acts like a molecular lock and key, allowing these cells to recognize and bind to specific invaders like viruses or bacteria. When a T cell receptor successfully matches with pieces of a pathogen displayed by other immune cells, it triggers the T cell to spring into action, either destroying infected cells or coordinating the immune response. Think of it as the immune system's way of checking ID badges to make sure it's attacking the right target and not accidentally harming the body's own healthy cells.