Th1Th2
Th1Th2 refers to the two major CD4+ T helper cell lineages, Th1 and Th2, and the balance between them. Th1 cells promote cell-mediated immunity to intracellular pathogens through cytokines like IFN-γ and IL-2; their differentiation is driven by IL-12 produced by dendritic cells and IFN-γ, with T-bet as the master transcription factor. Th2 cells support humoral immunity and defense against extracellular parasites, primarily via IL-4, IL-5, and IL-13; GATA-3 governs their differentiation. Each subset activates distinct effector pathways: Th1 activates macrophages; Th2 supports B cell activation and antibody production, including IgE class switching.
The Th1/Th2 paradigm also describes cross-regulation: cytokines from one lineage inhibit the development or function of
In research and clinical contexts, Th1/Th2 polarization remains a foundational concept for understanding adaptive immunity, vaccine