Article

Regulation of Cytokine Secretion in Human CD127(+) LTi-like Innate Lymphoid Cells by Toll-like Receptor 2

Department of Immunology, Genentech, South San Francisco, CA 94080, USA.
Immunity (Impact Factor: 19.75). 11/2010; 33(5):752-64. DOI: 10.1016/j.immuni.2010.10.012
Source: PubMed

ABSTRACT Lymphoid tissue inducer cells are members of an emerging family of innate lymphoid cells (ILC). Although these cells were originally reported to produce cytokines such as interleukin-17 (IL-17) and IL-22, we demonstrate here that human CD127(+)RORC(+) and CD56(+)CD127(+) LTi-like ILC also express IL-2, IL-5, and IL-13 after activation with physiologic stimuli such as common γ-chain cytokines, Toll-like receptor (TLR) 2 ligands, or IL-23. Whereas TLR2 signaling induced IL-5, IL-13, and IL-22 expression in a nuclear factor κB (NF-κB)-dependent manner, IL-23 costimulation induced only IL-22 production. CD127(+) LTi-like ILC displayed clonal heterogeneity for IL-13 and IL-5 production, suggesting in vivo polarization. Finally, we identified a role for autocrine IL-2 signaling in mediating the effects of TLR2 stimulation on CD56(+)CD127(+) and CD127(+) LTi-like ILC. These results indicate that human LTi-like ILC can directly sense bacterial components and unravel a previously unrecognized functional heterogeneity among this important population of innate lymphoid cells.

2 Followers
 · 
141 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Innate lymphoid cells (ILCs) are an emerging family of innate hematopoietic cells producing inflammatory cytokines and involved in the pathogenesis of several immune-mediated diseases. The aim of this study was to characterize the tissue distribution of ILCs in celiac disease (CD), a gluten-driven enteropathy, and analyze their role in gut tissue damage. ILC subpopulations were analyzed in lamina propria mononuclear cells (LPMCs) isolated from duodenal biopsies of CD patients and healthy controls (CTR) and jejunal specimens of patients undergoing gastro-intestinal bypass by flow cytometry. Cytokines and Toll-like receptors (TLR) were assessed in ILCs either freshly isolated or following incubation of control LPMC with peptidoglycan, poly I:C, or CpG, the agonists of TLR2, TLR3, or TLR9 respectively, by flow cytometry. The role of ILCs in gut tissue damage was evaluated in a mouse model of poly I:C-driven small intestine atrophy. Although the percentage of total ILCs did not differ between CD patients and CTR, ILCs producing TNF-α and IFN-γ were more abundant in CD mucosa compared to controls. ILCs expressed TLR2, TLR3 and TLR9 but neither TLR7 nor TLR4. Stimulation of LPMC with poly I:C but not PGN or CpG increased TNF-α and IFN-γ in ILCs. RAG1-deficient mice given poly I:C exhibited increased frequency of TNF-α but not IFN-γ/IL17A-producing ILCs in the gut and depletion of ILCs prevented the poly I:C-driven intestinal damage. Our data indicate that CD-related inflammation is marked by accumulation of ILCs producing TNF-α and IFN-γ in the mucosa. Moreover, ILCs express TLR3 and are functionally able to respond to poly I:C with increased synthesis of TNF-α thus contributing to small intestinal atrophy.
    PLoS ONE 05/2015; 10(5):e0126291. DOI:10.1371/journal.pone.0126291 · 3.53 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Innate lymphoid cells (ILCs) are identified as novel population of hematopoietic cells which protect the body by coordinating the innate immune response against a wide range of threats including infections, tissue damages and homeostatic disturbances. ILCs, particularly ILC2 cells, are found throughout the body including the brain. ILCs are morphologically similar to lymphocytes, express and release high levels of T-helper (Th)1, Th2 and Th17 cytokines but do not express classical cell-surface markers that are associated with other immune cell lineages. Three types of ILCs (ILC1, 2 & 3) have been reported depending upon the cytokines produced. ILC1 cells encompass natural killer (NK) cells and interferon (IFN)- releasing cells; ILC2 cells release the Th2 cytokines, IL-5, IL-9 and IL-13 in response to IL-25 and IL-33; and ILC3 cells which release IL-17 and IL-22. ILC2 cells have been implicated in mucosal reactions occurring in animal models of allergic asthma and virus-induced lung disorders resulting in the regulation of airway remodeling and tissue homeostasis. There is evidence for increased ILC2 cell numbers in allergic responses in man but little is known about the role of ILCs in chronic obstructive pulmonary disease (COPD). Further understanding of the characteristics of ILCs such as their origin, location and phenotypes and function would help to clarify the role of these cells in the pathogenesis of various lung diseases. In this review we will focus on the role of ILC2 cells and consider their origin, function, location and possible role in the pathogenesis of the chronic inflammatory disorders such as asthma and COPD.