T cell activation

T-cell activation is a critical process in the immune response. It begins when a specific type of white blood cell, called a T-cell, encounters an antigen, which is a foreign substance like a virus or bacteria. This encounter typically occurs in the lymph nodes. The T-cell binds to the antigen presented by another immune cell, known as an antigen-presenting cell. This interaction, along with additional signals, triggers the T-cell to become active. Once activated, T-cells can multiply and help eliminate the invader by attacking infected cells or coordinating other immune responses.