Immunreceptorer

Immunreceptorer are molecules found on the surface of or inside immune cells that play a crucial role in recognizing and responding to foreign substances. These substances, known as antigens, can be parts of pathogens like bacteria and viruses, or even abnormal cells such as cancer cells. When an immunreceptor encounters its specific antigen, it triggers a cascade of signals within the immune cell, leading to a coordinated immune response.

There are two main types of immunreceptors: B cell receptors (BCRs) and T cell receptors (TCRs). BCRs are found on B lymphocytes and are responsible for recognizing intact antigens. Upon activation by an antigen, B cells differentiate into plasma cells that produce antibodies, which are soluble proteins that neutralize or mark pathogens for destruction. TCRs are found on T lymphocytes and recognize antigen fragments presented by other cells. There are different types of T cells, including helper T cells that coordinate the immune response and cytotoxic T cells that directly kill infected or cancerous cells.

Beyond BCRs and TCRs, the immune system utilizes a broad array of other immunreceptors. Pattern recognition receptors (PRRs), for instance, are critical for innate immunity. They recognize conserved molecular patterns found on broad classes of microbes, initiating a rapid, non-specific defense. Immune responses are highly regulated, and immunreceptors are also involved in dampening or terminating immune reactions to prevent excessive damage to host tissues. The intricate interplay of these various immunreceptors ensures an effective and precisely controlled defense against a vast array of threats.