T-helper 2-polarized immune response (Th2 response)

The T-helper 2 (Th2)-polarized immune response is a specialized arm of the adaptive immune system, primarily orchestrated by CD4+ T cells that have differentiated into the Th2 lineage under the influence of the master transcription factor GATA3. This response is characterized by the secretion of a signature set of "Type 2" cytokines, including IL-4, IL-5, and IL-13, which are critical for coordinating defenses against extracellular parasites like helminths and facilitating humoral immunity via B-cell antibody class switching to IgE. While physiologically protective in the context of parasitic infections, an overactive or dysregulated Th2 response is the fundamental driver of atopic and allergic diseases, such as asthma, atopic dermatitis, and allergic rhinitis. In these pathological states, the Th2 milieu promotes chronic inflammation marked by eosinophil recruitment, mucus hypersecretion, and airway or skin hyperresponsiveness. Consequently, the Th2 pathway has become a major focus of pharmaceutical development, with numerous monoclonal antibodies designed to neutralize its key cytokines or block their respective receptors. By inhibiting these specific molecular nodes, therapeutic agents can effectively resolve the systemic and local inflammation characteristic of Th2-high disease endotypes. However, modulating this response requires careful monitoring for potential adverse effects, such as increased susceptibility to certain parasitic infections and specific localized reactions like conjunctivitis.

Other names

Type 2 immune responseTh2-mediated immunityType 2 inflammationHumoral immune response

Inhibition of Type 2 cytokines (including IL-4, IL-5, IL-13, and IL-31) or their corresponding receptors (IL-4Rα, IL-5Rα, and IL-31RA) to suppress the inflammatory cascade, reduce eosinophil recruitment, and prevent IgE-mediated hypersensitivity.