primärbackupreaktion

The primary backup reaction, also known as the primary immune response, is the initial reaction of the immune system to an antigen, which is a foreign substance that triggers an immune response. This reaction is characterized by the activation of naive T cells and the production of antibodies. The primary backup reaction is typically slower and less effective than the secondary immune response, which occurs upon subsequent exposure to the same antigen.

During the primary backup reaction, antigen-presenting cells (APCs) such as dendritic cells and macrophages phagocytose the antigen and present antigen fragments on their surface using major histocompatibility complex (MHC) molecules. This process is crucial for activating naive T cells. Naive T cells, which are T cells that have not yet encountered the antigen, are activated when they recognize the antigen-MHC complex. Activated T cells then differentiate into effector T cells, which help eliminate the antigen, and memory T cells, which provide long-term protection against the antigen.

Simultaneously, B cells, which are a type of white blood cell, are activated by the antigen. Activated B cells differentiate into plasma cells, which produce antibodies specific to the antigen. These antibodies can neutralize the antigen, mark it for destruction by other immune cells, or directly kill the antigen. The primary backup reaction is essential for establishing immunity against new pathogens and is the foundation for the development of long-term immunity.