TY - JOUR
T1 - Semaphorin 4D inhibits neutrophil activation and is involved in the pathogenesis of neutrophil-mediated autoimmune vasculitis
AU - Nishide, Masayuki
AU - Nojima, Satoshi
AU - Ito, Daisuke
AU - Takamatsu, Hyota
AU - Koyama, Shohei
AU - Kang, Sujin
AU - Kimura, Tetsuya
AU - Morimoto, Keiko
AU - Hosokawa, Takashi
AU - Hayama, Yoshitomo
AU - Kinehara, Yuhei
AU - Kato, Yasuhiro
AU - Nakatani, Takeshi
AU - Nakanishi, Yoshimitsu
AU - Tsuda, Takeshi
AU - Park, Jeong Hoon
AU - Hirano, Toru
AU - Shima, Yoshihito
AU - Narazaki, Masashi
AU - Morii, Eiichi
AU - Kumanogoh, Atsushi
N1 - Funding Information:
This work was supported by research grants from AMED-CREST and AMED (to AK); COI stream and SRIP grants from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan (to AK); from the Ministry of Health, Labour and Welfare of Japan (to AK); from MEXT/JSPS KAKENHI Grant Number 15612282 (to SN) and from the Takeda Science Foundation (to SN) and the Ube Industries Foundation (to SN).
Publisher Copyright:
© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
PY - 2017/8/1
Y1 - 2017/8/1
N2 - Objectives Inappropriate activation of neutrophils plays a pathological role in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The aim of this study was to investigate the functions of semaphorin 4D (SEMA4D) in regulation of neutrophil activation, and its involvement in AAV pathogenesis. Methods Serum levels of soluble SEMA4D were evaluated by ELISA. Blood cell-surface expression of membrane SEMA4D was evaluated by flow cytometry. To determine the functional interactions between neutrophil membrane SEMA4D and endothelial plexin B2, wild-type and SEMA4D -/- mice neutrophils were cultured with an endothelial cell line (MS1) stained with SYTOX green, and subjected to neutrophil extracellular trap (NET) formation assays. The efficacy of treating human neutrophils with recombinant plexin B2 was assessed by measuring the kinetic oxidative burst and NET formation assays. Results Serum levels of soluble SEMA4D were elevated in patients with AAV and correlated with disease activity scores. Cell-surface expression of SEMA4D was downregulated in neutrophils from patients with AAV, a consequence of proteolytic cleavage of membrane SEMA4D. Soluble SEMA4D exerted pro-inflammatory effects on endothelial cells. Membranous SEMA4D on neutrophils bound to plexin B2 on endothelial cells, and this interaction decreased NET formation. Recombinant plexin B2 suppressed neutrophil Rac1 activation through SEMA4D's intracellular domain, and inhibited pathogen-induced or ANCA-induced oxidative burst and NET formation. Conclusions Neutrophil surface SEMA4D functions as a negative regulator of neutrophil activation. Proteolytic cleavage of SEMA4D as observed in patients with AAV may amplify neutrophil-mediated inflammatory responses. SEMA4D is a promising biomarker and potential therapeutic target for AAV.
AB - Objectives Inappropriate activation of neutrophils plays a pathological role in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The aim of this study was to investigate the functions of semaphorin 4D (SEMA4D) in regulation of neutrophil activation, and its involvement in AAV pathogenesis. Methods Serum levels of soluble SEMA4D were evaluated by ELISA. Blood cell-surface expression of membrane SEMA4D was evaluated by flow cytometry. To determine the functional interactions between neutrophil membrane SEMA4D and endothelial plexin B2, wild-type and SEMA4D -/- mice neutrophils were cultured with an endothelial cell line (MS1) stained with SYTOX green, and subjected to neutrophil extracellular trap (NET) formation assays. The efficacy of treating human neutrophils with recombinant plexin B2 was assessed by measuring the kinetic oxidative burst and NET formation assays. Results Serum levels of soluble SEMA4D were elevated in patients with AAV and correlated with disease activity scores. Cell-surface expression of SEMA4D was downregulated in neutrophils from patients with AAV, a consequence of proteolytic cleavage of membrane SEMA4D. Soluble SEMA4D exerted pro-inflammatory effects on endothelial cells. Membranous SEMA4D on neutrophils bound to plexin B2 on endothelial cells, and this interaction decreased NET formation. Recombinant plexin B2 suppressed neutrophil Rac1 activation through SEMA4D's intracellular domain, and inhibited pathogen-induced or ANCA-induced oxidative burst and NET formation. Conclusions Neutrophil surface SEMA4D functions as a negative regulator of neutrophil activation. Proteolytic cleavage of SEMA4D as observed in patients with AAV may amplify neutrophil-mediated inflammatory responses. SEMA4D is a promising biomarker and potential therapeutic target for AAV.
KW - Autoimmune Diseases
KW - Granulomatosis with polyangiitis
KW - Inflammation
KW - Systemic vasculitis
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U2 - 10.1136/annrheumdis-2016-210706
DO - 10.1136/annrheumdis-2016-210706
M3 - Article
C2 - 28416516
AN - SCOPUS:85024393684
SN - 0003-4967
VL - 76
SP - 1440
EP - 1448
JO - Annals of the rheumatic diseases
JF - Annals of the rheumatic diseases
IS - 8
ER -
