Neutrophil Gelatinase-Associated Lipocalin Protects from ANCA-Induced GN by Inhibiting T H 17 Immunity

J Am Soc Nephrol. 2020 Jul;31(7):1569-1584. doi: 10.1681/ASN.2019090879. Epub 2020 Jun 2.

Abstract

Background: Neutrophil gelatinase-associated lipocalin (NGAL) is a diagnostic marker of intrinsic kidney injury produced by damaged renal cells and by neutrophils. ANCA-associated vasculitis features necrotizing crescentic GN (NCGN), and ANCA-activated neutrophils contribute to NCGN. Whether NGAL plays a mechanistic role in ANCA-associated vasculitis is unknown.

Methods: We measured NGAL in patients with ANCA-associated vasculitis and mice with anti-myeloperoxidase (anti-MPO) antibody-induced NCGN. We compared kidney histology, neutrophil functions, T cell proliferation and polarization, renal infiltrating cells, and cytokines in wild-type and NGAL-deficient chimeric mice with anti-MPO antibody-induced NCGN. To assess the role of TH17 immunity, we transplanted irradiated MPO-immunized MPO-deficient mice with bone marrow from either wild-type or NGAL-deficient mice; we also transplanted irradiated MPO-immunized MPO/IL-17A double-deficient mice with bone marrow from either IL-17A-deficient or NGAL/IL-17A double-deficient mice.

Results: Mice and patients with active ANCA-associated vasculitis demonstrated strongly increased serum and urinary NGAL levels. ANCA-stimulated neutrophils released NGAL. Mice with NGAL-deficient bone marrow developed worsened MPO-ANCA-induced NCGN. Intrinsic neutrophil functions were similar in NGAL-deficient and wild-type neutrophils, whereas T cell immunity was increased in chimeric mice with NGAL-deficient neutrophils with more renal infiltrating TH17 cells. NGAL-expressing neutrophils and CD3+ T cells were in close proximity in kidney and spleen. CD4+ T cells showed no intrinsic difference in proliferation and polarization in vitro, whereas iron siderophore-loaded NGAL suppressed TH17 polarization. We found significantly attenuated NCGN in IL-17A-deficient chimeras compared with MPO-deficient mice receiving wild-type bone marrow, as well as in NGAL/IL-17A-deficient chimeras compared with NGAL-deficient chimeras.

Conclusions: Our findings support that bone marrow-derived, presumably neutrophil, NGAL protects from ANCA-induced NCGN by downregulating TH17 immunity.

Keywords: ANCA glomerulonephritis; TH17; neutrophil; ngal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Animals
  • Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / metabolism
  • Antibodies, Antineutrophil Cytoplasmic
  • CD28 Antigens / metabolism
  • CD3 Complex / metabolism
  • CD4-Positive T-Lymphocytes / physiology
  • Cell Proliferation
  • Chimera
  • Disease Models, Animal
  • Female
  • Glomerulonephritis / immunology*
  • Glomerulonephritis / metabolism*
  • Glomerulonephritis / pathology
  • Humans
  • Immunity, Cellular
  • Interleukin-17 / genetics
  • Kidney / pathology
  • Lipocalin-2 / genetics*
  • Lipocalin-2 / metabolism*
  • Male
  • Mice
  • Middle Aged
  • Neutrophils / metabolism
  • Peroxidase / immunology
  • Siderophores / metabolism
  • Spleen / pathology
  • Th17 Cells / immunology*

Substances

  • Antibodies, Antineutrophil Cytoplasmic
  • CD28 Antigens
  • CD3 Complex
  • Il17a protein, mouse
  • Interleukin-17
  • LCN2 protein, human
  • Lipocalin-2
  • Siderophores
  • Lcn2 protein, mouse
  • Peroxidase