immunological

Immunological refers to the immune system and the study of its functions, responses, and disorders in health and disease.

The immune system comprises innate and adaptive components. Innate immunity provides immediate, non-specific defense through barriers and cells such as macrophages, dendritic cells, neutrophils, and natural killer cells. Adaptive immunity is targeted and specific, driven by B lymphocytes that produce antibodies and T lymphocytes that execute cellular responses. Humoral immunity involves antibodies circulating in body fluids, while cellular immunity relies on T cells to recognize antigens presented by MHC molecules on antigen-presenting cells.

Recognition of antigens is mediated by receptors on lymphocytes; clonal selection expands specific cells, creating immunological memory that enhances future responses to the same pathogen. Immunological tolerance prevents reactions against self, reducing autoimmunity.

Dysregulation can lead to immunological disorders, including autoimmune diseases, allergies, and immunodeficiencies. Vaccination exploits immunological memory to confer protection. Transplantation and graft rejection involve immunological recognition of foreign MHC molecules, influencing compatibility and the need for immunosuppressive strategies.

In research and clinical testing, immunology relies on assays such as ELISA, flow cytometry, and immunohistochemistry, as well as antibodies and vaccines, to diagnose disease, monitor immune status, and study immune mechanisms. The field intersects with infectious disease, oncology, rheumatology, and vaccinology, guiding both basic science and therapeutic approaches.