IL-17 Induction by ArtinM is Due to Stimulation of IL-23 and IL-1 Release and/or Interaction with CD3 in CD4+ T Cells

PLoS One. 2016 Feb 22;11(2):e0149721. doi: 10.1371/journal.pone.0149721. eCollection 2016.

Abstract

ArtinM is a D-mannose-binding lectin extracted from the seeds of Artocarpus heterophyllus that interacts with TLR2 N-glycans and activates antigen-presenting cells (APCs), as manifested by IL-12 production. In vivo ArtinM administration induces Th1 immunity and confers protection against infection with several intracellular pathogens. In the murine model of Candida albicans infection, it was verified that, in addition to Th1, ArtinM induces Th17 immunity manifested by high IL-17 levels in the treated animals. Herein, we investigated the mechanisms accounting for the ArtinM-induced IL-17 production. We found that ArtinM stimulates the IL-17 production by spleen cells in BALB/c or C57BL/6 mice, a response that was significantly reduced in the absence of IL-23, MyD88, or IL-1R. Furthermore, we showed that ArtinM directly induced the IL-23 mRNA expression and the IL-1 production by macrophages. Consistently, in cell suspensions depleted of macrophages, the IL-17 production stimulated by ArtinM was reduced by 53% and the exogenous IL-23 acted synergistically with ArtinM in promoting IL-17 production by spleen cell suspensions. We verified that the absence of IL-23, IL-1R, or MyD88 inhibited, but did not block, the IL-17 production by ArtinM-stimulated spleen cells. Therefore, we investigated whether ArtinM exerts a direct effect on CD4+ T cells in promoting IL-17 production. Indeed, spleen cell suspensions depleted of CD4+ T cells responded to ArtinM with very low levels of IL-17 release. Likewise, isolated CD4+ T cells under ArtinM stimulus augmented the expression of TGF-β mRNA and released high levels of IL-17. Considering the observed synergism between IL-23 and ArtinM, we used cells from IL-23 KO mice to assess the direct effect of lectin on CD4+ T cells. We verified that ArtinM increased the IL-17 production significantly, a response that was inhibited when the CD4+ T cells were pre-incubated with anti-CD3 antibody. In conclusion, ArtinM stimulates the production of IL-17 by CD4+ T cells in two major ways: (I) through the induction of IL-23 and IL-1 by APCs and (II) through the direct interaction with CD3 on the CD4+ T cells. This study contributes to elucidation of mechanisms accounting for the property of ArtinM in inducing Th17 immunity and opens new perspectives in designing strategies for modulating immunity by using carbohydrate recognition agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Artocarpus / chemistry*
  • CD3 Complex / genetics
  • CD3 Complex / immunology*
  • Candida albicans / immunology
  • Candidiasis / drug therapy
  • Candidiasis / genetics
  • Candidiasis / immunology
  • Interleukin-1 / genetics
  • Interleukin-1 / immunology*
  • Interleukin-17 / genetics
  • Interleukin-17 / immunology*
  • Interleukin-23 / genetics
  • Interleukin-23 / immunology*
  • Mannose-Binding Lectin* / chemistry
  • Mannose-Binding Lectin* / pharmacology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Knockout
  • Myeloid Differentiation Factor 88 / genetics
  • Myeloid Differentiation Factor 88 / immunology
  • Plant Lectins* / chemistry
  • Plant Lectins* / pharmacology
  • Receptors, Interleukin-1 / genetics
  • Receptors, Interleukin-1 / immunology
  • Th1 Cells / immunology
  • Th17 Cells / immunology*

Substances

  • CD3 Complex
  • Interleukin-1
  • Interleukin-17
  • Interleukin-23
  • Mannose-Binding Lectin
  • Myd88 protein, mouse
  • Myeloid Differentiation Factor 88
  • Plant Lectins
  • Receptors, Interleukin-1

Grants and funding

This research was financially supported by Fundação de Amparo a Pesquisa do Estado de São Paulo (grant numbers 2006/60642-2, 2007/558879-7, 2010/51763-6, 2012/12950-0, 2012/09611-0 and 2013/04088-0), Conselho Nacional de Desenvolvimento Científico e Tecnológico (475357/2013-2), Financiadora de Estudos e Projetos (0110045900), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior and Fundação de Apoio ao Ensino, Pesquisa e Assistência do Hospital das Clínicas da Faculdade deMedicina de Ribeirão Preto.