Interleukin-17 Is Required for T Helper 1 Cell Immunity and Host Resistance to the Intracellular Pathogen Francisella tularensis

Academic Article


  • The importance of T helper type 1 (Th1) cell immunity in host resistance to the intracellular bacterium Francisella tularensis is well established. However, the relative roles of interleukin (IL)-12-Th1 and IL-23-Th17 cell responses in immunity to F. tularensis have not been studied. The IL-23-Th17 cell pathway is critical for protective immunity against extracellular bacterial infections. In contrast, the IL-23-Th17 cell pathway is dispensable for protection against intracellular pathogens such as Mycobacteria. Here we show that the IL-23-Th17 pathway regulates the IL-12-Th1 cell pathway and was required for protective immunity against F.tularensis live vaccine strain. We show that IL-17A, but not IL-17F or IL-22, induced IL-12 production in dendritic cells and mediated Th1 responses. Furthermore, we show that IL-17A also induced IL-12 and interferon-γ production in macrophages and mediated bacterial killing. Together, these findings illustrate a biological function for IL-17A in regulating IL-12-Th1 cell immunity and host responses to an intracellular pathogen. © 2009 Elsevier Inc. All rights reserved.
  • Published In

  • Immunity  Journal
  • Digital Object Identifier (doi)

    Author List

  • Lin Y; Ritchea S; Logar A; Slight S; Messmer M; Rangel-Moreno J; Guglani L; Alcorn JF; Strawbridge H; Park SM
  • Start Page

  • 799
  • End Page

  • 810
  • Volume

  • 31
  • Issue

  • 5