Th2biased

Th2biased refers to an immune profile in which T helper 2 (Th2) cells are the predominant CD4+ T cell response to antigen exposure. This bias is characterized by the production of cytokines such as interleukin-4 (IL-4), IL-5, and IL-13, which shape humoral and mucosal immunity and influence eosinophilic inflammation.

Biology and mechanisms: IL-4 and IL13 drive B cell class switching to immunoglobulin E (IgE) and support IgG4 production in humans, while IL-5 promotes eosinophil growth and recruitment. IL-4, IL-13, and the transcription factor GATA3 act as central regulators of Th2 differentiation. Dendritic cells, basophils, and mast cells can contribute to Th2-skewing by providing IL-4 and other signals, and the resulting Th2 response can promote alternative macrophage activation and mucus production. The bias arises from a combination of genetic predisposition, early-life environmental exposures, and the context of antigen presentation.

Clinical relevance: Th2-biased responses are effective against certain parasites and contribute to robust antibody-mediated immunity, but they are central to many allergic diseases, including allergic rhinitis, asthma, and atopic dermatitis, where IgE elevation and eosinophilia are common. Th2 bias can influence responses to vaccines and infections and may be counterbalanced by regulatory T cells and Th1/Th17 pathways.

Measurement and therapy: Research and clinical assessment use cytokine profiles, IgE levels, and eosinophil counts to gauge Th2 bias. Therapeutically, strategies that inhibit IL-4 and IL-13 signaling (for example, IL-4Rα blockers) or target IL-5 are used to ameliorate allergic diseases.