T(H)2 heterogeneity: Does function follow form?
T(H)2 immune responses are required for the 2 fundamental pathological processes characteristic of allergic disease: IgE-mediated hypersensitivity and eosinophilic inflammation. The 3 established T(H)2 cytokines, IL-4, IL-5, and IL-13, each play a nonredundant role in allergic disease pathology. The recent explosion of T(H) subpopulations combined with the wide availability of polychromatic cytokine staining has facilitated the discovery of T(H)2 lineage heterogeneity. In this article we review T(H)2 heterogeneity and ask the following question: At what point do these subpopulations graduate from in vitro curiosities to immunologically robust therapeutic targets? We propose criteria to establish a T-cell subset as a biologically relevant entity and address the evidence to support these T(H)2 subpopulations having a unique function or specific contribution to allergic pathology or host defense.
Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-1881, USA. cprussin@niaid.nih.gov
Calman
C
Prussin
Yuzhi
Y
Yin
Bhaskar
B
Upadhyaya
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology; D019070:Cell Lineage; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis / Q000276:immunology*; D007249:Inflammation; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
D015415:Biomarkers; D016207:Cytokines