Decreased Langerhans cell responses to IL-36γ: altered innate immunity in patients with recurrent respiratory papillomatosis

Mol Med. 2014 Aug 28;20(1):372-80. doi: 10.2119/molmed.2014.00098.

Abstract

Recurrent respiratory papillomatosis (RRP) is a rare, chronic disease caused by human papillomaviruses (HPVs) types 6 and 11 that is characterized by the polarization of adaptive immune responses that support persistent HPV infection. Respiratory papillomas express elevated mRNA levels of IL-36γ, a proinflammatory cytokine in comparison to autologous clinically normal laryngeal tissues; however there is no evidence of inflammation in these lesions. Consistent with this, respiratory papillomas do not contain TH1-like CD4(+) T-cells or cytotoxic CD8(+) T-cells, but instead contain a predominance of TH2-like and T regulatory cells (Tregs). In addition, papillomas also are infiltrated with immature Langerhans cells (iLCs). In this study, we show that papilloma cells express IL-36γ protein, and that human keratinocytes transduced with HPV11 have reduced IL-36γ secretion. We now provide the first evidence that peripheral blood-derived iLCs respond to IL-36γ by expressing inflammatory cytokines and chemokines. When stimulated with IL-36γ, iLCs from patients with RRP had lower expression levels of the TH2-like chemokine CCL-20 as compared with controls. Patients' iLCs also had decreased steady state levels of CCL-1, which is a proinflammatory chemokine. Moreover, CCL-1 levels in iLCs inversely correlated with the severity of RRP. The combined decrease of TH1- and a TH2-like chemokines by iLCs from patients could have consequences in the priming of IFN-γ expression by CD8(+) T-cells. Taken together, our results suggest that, in RRP, there is a defect in the proinflammatory innate immune responses made by iLCs in response to IL-36γ. The consequence of this defect may lead to persistent HPV infection by failing to support an effective HPV-specific, TH1-like and/or Tc1-like adaptive response, thus resulting in the predominant TH2-like and/or Treg micromilieu present in papillomas.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cells, Cultured
  • Chemokine CCL1 / genetics
  • Chemokine CCL1 / immunology
  • Human papillomavirus 11
  • Humans
  • Immunity, Innate
  • Interleukin-1 / genetics
  • Interleukin-1 / immunology*
  • Interleukin-1beta / genetics
  • Interleukin-1beta / immunology
  • Keratinocytes / immunology
  • Keratinocytes / virology
  • Langerhans Cells / immunology*
  • Larynx / immunology
  • Papillomavirus Infections / immunology*
  • Respiratory Tract Infections / immunology*

Substances

  • CCL1 protein, human
  • Chemokine CCL1
  • IL36G protein, human
  • Interleukin-1
  • Interleukin-1beta

Supplementary concepts

  • Recurrent respiratory papillomatosis