immunreakciója

Immunreakciója, the immune response of a biological organism, is a complex physiological process that protects the body from harmful pathogens such as bacteria, viruses, fungi, and parasites. It is initiated when the immune system recognizes a foreign antigen, a specific molecular structure present on the pathogen's surface. The response can be classified into two main categories: innate and adaptive immunity. Innate immunity provides the first line of defense through physical barriers, phagocytic cells such as macrophages and neutrophils, natural killer cells, and the complement system. Adaptive immunity is slower to develop but highly specific; it involves T lymphocytes and B lymphocytes. T cells either directly kill infected cells or help coordinate the immune response, while B cells produce antibodies that bind to antigens, neutralize toxins, and facilitate phagocytosis. The adaptive response also generates memory cells, enabling a faster and stronger reaction upon subsequent exposures to the same pathogen. In some cases, immunreakciója can become dysregulated, leading to allergic reactions, autoimmunity, or immunodeficiency. Understanding the mechanisms of the immune response is essential for diagnosing infections, developing vaccines, and designing targeted immunotherapies.