IL-17 family cytokines and the expanding diversity of effector T cell lineages.
Since its conception two decades ago, the Th1-Th2 paradigm has provided a framework for understanding T cell biology and the interplay of innate and adaptive immunity. Naive T cells differentiate into effector T cells with enhanced functional potential for orchestrating pathogen clearance largely under the guidance of cytokines produced by cells of the innate immune system that have been activated by recognition of those pathogens. This secondary education of post-thymic T cells provides a mechanism for appropriately matching adaptive immunity to frontline cues of the innate immune system. Owing in part to the rapid identification of novel cytokines of the IL-17 and IL-12 families using database searches, the factors that specify differentiation of a new effector T cell lineage-Th17-have now been identified, providing a new arm of adaptive immunity and presenting a unifying model that can explain many heretofore confusing aspects of immune regulation, immune pathogenesis, and host defense.
Weaver
Casey T
CT
Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA. cweaver@uab.edu
Hatton
Robin D
RD
Mangan
Paul R
PR
Harrington
Laurie E
LE
D000818:Animals; D002454:Cell Differentiation / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D018664:Interleukin-12 / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D020381:Interleukin-17 / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology
D020381:Interleukin-17; D018664:Interleukin-12