Limmunologie

Limmunologie is the study of the immune system and its functions, disorders, and responses. The immune system protects organisms from infection, injury, and malignant transformation through two arms: innate immunity, which provides immediate but non-specific defense, and adaptive immunity, which targets specific pathogens and forms immunological memory. Key players include leukocytes such as macrophages, neutrophils, dendritic cells, B cells, and T cells; antibodies; and signaling molecules called cytokines. Immune responses are coordinated by lymphoid organs, including bone marrow, thymus, spleen, lymph nodes, and mucosal-associated lymphoid tissue.

Recognition of pathogens involves pattern recognition receptors that detect conserved molecular patterns, leading to phagocytosis, antigen presentation, and the activation of T and B cells. Clonal selection expands cells specific to an encountered antigen, producing antibodies and cytotoxic or helper functions. Tolerance mechanisms prevent reactivity against self, while dysregulation can lead to autoimmunity, allergy, or immunodeficiency.

Techniques in limmunologie include flow cytometry, enzyme-linked immunosorbent assays, polymerase chain reaction, sequencing, and imaging; animal models and human clinical studies test hypotheses and therapies. In recent decades, immunology has driven vaccine development, autoimmune disease treatment, and immunotherapies such as checkpoint inhibitors and chimeric antigen receptor (CAR) T cell therapy.

Geopolitical and ethical aspects include animal use, access to vaccines, and equitable distribution of immunotherapies. The field continues to evolve with systems biology and bioinformatics approaches, enabling precision immunology and personalized vaccines. Historical milestones include Jenner’s vaccination work, Metchnikoff’s phagocytosis concept, Ehrlich’s side-chain theory, and Kohler and Milstein’s monoclonal antibodies.