Abstract

NETs constitute a network of DNA and proteins released by neutrophils in response to infectious and immunologic triggers. NET proteins are recognized as autoantigens in ANCA vasculitis; limited knowledge is available in other autoimmune pathologies. The composition of NETs produced ex vivo by resting and Phorbol-myristate acetate (PMA) stimulated neutrophils was analyzed by high-throughput Fusion Orbitrap technology in 16 patients with Systemic Lupus Erythematosus/Lupus nephritis (9 SLE/7 LN) and in 11 controls. Seven-hundred proteins were characterized and specific fingerprints discriminated LN from SLE. We focused on methyl-oxidized αenolase (methionine sulfoxide 93) that was markedly increased in NETs from LN and was localized in NET filaments in tight connection and outlying DNA. The isotype of anti-αenolase antibodies was IgG2 in LN and IgG4 in other autoimmune glomerulonephritis (Membranous Nephropathy, MN); serum anti-αenolase IgG2 were higher in LN than in SLE and absent in MN. The same IgG2 antibodies recognized 5 epitopes of the protein one containing methionine sulphoxide 93. In conclusion, specific NET protein fingerprints characterize different subsets of SLE; methyl-oxidized αenolase is over-expressed in LN. Circulating anti-αenolase IgG2 recognize the oxidized epitope and are high in serum of LN patients. Post-translational modified NET proteins contribute to autoimmunity in patients with LN.

Details

Title
Neutrophil Extracellular Traps protein composition is specific for patients with Lupus nephritis and includes methyl-oxidized αenolase (methionine sulfoxide 93)
Author
Bruschi Maurizio 1 ; Petretto, Andrea 2 ; Santucci, Laura 1 ; Vaglio Augusto 3 ; Pratesi Federico 4 ; Migliorini, Paola 4 ; Bertelli, Roberta 1 ; Lavarello Chiara 2 ; Bartolucci Martina 2 ; Candiano Giovanni 1 ; Prunotto Marco 5   VIAFID ORCID Logo  ; Ghiggeri Gian Marco 6 

1  Laboratory of Molecular Nephrology, IRCCS Istituto Giannina Gaslini, Genoa, Italy (GRID:grid.419504.d) (ISNI:0000 0004 1760 0109) 
2  Core Facilities-Proteomics Laboratory, IRCCS Istituto Giannina Gaslini, Genoa, Italy (GRID:grid.419504.d) (ISNI:0000 0004 1760 0109) 
3  University of Firenze, and Meyer Children’s Hospital, Department of Biomedical Experimental and Clinical Sciences “Mario Serio”, Firenze, Italy (GRID:grid.8404.8) (ISNI:0000 0004 1757 2304) 
4  University of Pisa, Department of Clinical and Experimental Medicine, Clinical Immunology Unit, Pisa, Italy (GRID:grid.5395.a) (ISNI:0000 0004 1757 3729) 
5  University of Geneva, School of Pharmaceutical Sciences, Geneva, Switzerland (GRID:grid.8591.5) (ISNI:0000 0001 2322 4988) 
6  Laboratory of Molecular Nephrology, IRCCS Istituto Giannina Gaslini, Genoa, Italy (GRID:grid.419504.d) (ISNI:0000 0004 1760 0109); Division of Nephrology, Dialysis, and Transplantation, Scientific Institute for Research and Health Care (IRCCS), IRCCS Istituto Giannina Gaslini, Genoa, Italy (GRID:grid.419504.d) (ISNI:0000 0004 1760 0109) 
Publication year
2019
Publication date
2019
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41598-019-44379-w
ProQuest document ID
2231410655
Copyright
© The Author(s) 2019. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.