immunogének

Immunogens are substances that can elicit an immune response. This response typically involves the production of antibodies or the activation of immune cells, such as T lymphocytes. Not all foreign substances are immunogenic; for a substance to be considered an immunogen, it must be recognized by the immune system as foreign and capable of triggering a specific reaction. Key characteristics of an immunogen include its foreignness to the host, its molecular size (larger molecules are generally more immunogenic), its chemical composition (complex molecules like proteins and polysaccharides are more immunogenic than simple ones), and its dosage and route of administration.

The parts of an immunogen that are specifically recognized by antibodies or T cell receptors are called epitopes. A single immunogen can have multiple epitopes, each potentially triggering a different immune response. The immune system's ability to distinguish between self and non-self is crucial; substances produced by the body itself are typically not immunogenic, and an immune response against self-antigens leads to autoimmune diseases. Immunogens are fundamental to the development of immunity, including natural immunity acquired through infection and adaptive immunity stimulated by vaccines. Understanding immunogens is vital in immunology, vaccinology, and the study of allergic reactions and transplantation rejection.