Immune reaction

An immune reaction, also known as an immune response, is the coordinated physiological process by which an organism recognizes and defends itself against foreign pathogens, toxic substances, or malignant cells. It is not a single molecular target but a multi-layered biological phenomenon involving innate and adaptive systems, comprising various cell types like T cells, B cells, and macrophages, as well as molecular mediators such as cytokines and antibodies [3, 4, 6]. While critical for host defense, dysregulated immune reactions are central to the pathogenesis of diverse conditions, including chronic inflammation, autoimmune disorders, and hypersensitivity reactions [2, 7, 9]. In drug development, 'immune reaction' serves as an umbrella term for a wide range of therapeutic interventions that modulate specific components of the response, such as checkpoint inhibitors for oncology or biologics for autoimmune disease [5, 14, 18]. Because it represents a global biological outcome rather than a discrete protein or receptor, it is classified as a biological process rather than a specific therapeutic target.

Other names

Immune responseImmunological reactionHost defense responseAntigen-antibody reaction

Immunomodulation, including immunosuppression to reduce harmful reactions or immunostimulation to enhance defense mechanisms against pathogens and tumors.