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. 2018 Mar 13;22(11):2924-2936.
doi: 10.1016/j.celrep.2018.02.067.

Gasdermin D Exerts Anti-inflammatory Effects by Promoting Neutrophil Death

Hiroto Kambara  1 , Fei Liu  2 , Xiaoyu Zhang  3 , Peng Liu  2 , Besnik Bajrami  4 , Yan Teng  1 , Li Zhao  1 , Shiyi Zhou  1 , Hongbo Yu  5 , Weidong Zhou  6 , Leslie E Silberstein  1 , Tao Cheng  2 , Mingzhe Han  2 , Yuanfu Xu  2 , Hongbo R Luo  7
Affiliations

Gasdermin D Exerts Anti-inflammatory Effects by Promoting Neutrophil Death

Hiroto Kambara et al. Cell Rep. .

Abstract

Gasdermin D (GSDMD) is considered a proinflammatory factor that mediates pyroptosis in macrophages to protect hosts from intracellular bacteria. Here, we reveal that GSDMD deficiency paradoxically augmented host responses to extracellular Escherichia coli, mainly by delaying neutrophil death, which established GSDMD as a negative regulator of innate immunity. In contrast to its activation in macrophages, in which activated inflammatory caspases cleave GSDMD to produce an N-terminal fragment (GSDMD-cNT) to trigger pyroptosis, GSDMD cleavage and activation in neutrophils was caspase independent. It was mediated by a neutrophil-specific serine protease, neutrophil elastase (ELANE), released from cytoplasmic granules into the cytosol in aging neutrophils. ELANE-mediated GSDMD cleavage was upstream of the caspase cleavage site and produced a fully active ELANE-derived NT fragment (GSDMD-eNT) that induced lytic cell death as efficiently as GSDMD-cNT. Thus, GSDMD is pleiotropic, exerting both pro- and anti-inflammatory effects that make it a potential target for antibacterial and anti-inflammatory therapies.

Keywords: GSDMD; host defense; innate immunity; neutrophil death; neutrophil elastase.

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Conflict of interest statement

DECLARATION OF INTERESTS

The authors declare no competing interests.

Figures

Figure 1
Figure 1. GSDMD-Deficient Mice Display Augmented Bactericidal Activity
(A) E. coli clearance in inflamed peritoneal cavities. Live bacteria were quantified as total colony-forming units (CFU) in peritoneal lavage fluid (PLF). (B) Total CFUs in the indicated organs and peripheral blood 36 hr after E. coli challenge.
Figure 2
Figure 2. The Augmented Host Antibacterial Response in GSDMD-Deficient Mice Is the Result of Enhanced Neutrophil Accumulation
(A) In vitro phagocytosis assay. More than 200 neutrophils were counted in each group. (B) In vitro killing of E. coli by bone marrow neutrophils. In vitro bacterial killing capabilities were reflected by the decrease in CFUs. Intracellular bactericidal activity of neutrophils was assessed by treating samples with kanamycin to kill extracellular bacteria. (C) Phagocytosis of E. coli bioparticles by peripheral blood neutrophils. Results are the means (±SDs) of three independent experiments. (D) In vitro killing of E. coli by peripheral blood neutrophils. Results are the means (±SDs) of three independent experiments. (E) Total peritoneal cell and peritoneal neutrophil numbers in E. coli-challenged mice. Data shown at each time point are means ± SDs of four mice. (F) Chemokine and cytokine levels in peritoneal cavity. Results are the means (±SDs) of three independent experiments. *p < 0.05 versus WT.
Figure 3
Figure 3. Delayed Neutrophil Death Elevates Neutrophil Accumulation and Enhances the Host Defense Response in GSDMD-Deficient Mice
(A) Neutrophil recruitment during sterile inflammation. At the indicated times, TG-challenged mice were killed and peritoneal lavage fluid collected for FACS. Shown are representative FACS plots depicting recruited peritoneal neutrophils. (B) Total neutrophil content in the lavage fluid was calculated based on FACS analysis. Data shown at each time point are means ± SDs of three mice. (C) Neutrophil death during E. coli-induced peritonitis. Peritoneal cells were collected 48 hr after E. coli injection and then analyzed by FACS. Shown are representative FACS plots depicting dying peritoneal neutrophils (P2). See also Figures S2D and S2E. (D) The percentage of dying neutrophils in the lavage fluid was calculated based on FACS analysis. Data shown at each time point are means ± SDs of three mice. (E) Death of in vitro cultured WT and GSDMD-deficient bone marrow neutrophils. Shown are the percentage and absolute number of healthy neutrophils in the culture at time points indicated. Data shown are means ± SDs of three mice. See also Figures S3A–S3D. (F) Death of in vitro cultured WT and GSDMD-deficient peripheral blood neutrophils. All of the values represent means ± SDs of three separate experiments. (G) Death of in vitro cultured WT and GSDMD-deficient bone marrow neutrophils in the presence of E. coli. Bone marrow neutrophils were cultured with E. coli (1:5 ratio) for 2 hr. Data shown are means ± SDs of three mice. (H) Death of in vitro cultured WT and GSDMD-deficient peripheral blood neutrophils in the presence of E. coli. Data shown are means ± SDs of three mice. (I) In vivo death of adoptively transferred neutrophils. (J) The ratios of adoptively transferred WT and GSDMD-deficient neutrophils. The input control was normalized to 1, and the results shown are the ratios at 15 hr after the adoptive transfer. All of the values represent means ± SDs. *p < 0.05 versus WT.
Figure 4
Figure 4. The Cleavage and Activation of GSDMD in Neutrophils Is Mediated by ELANE in a Caspase-Independent Manner
(A) GSDMD is highly expressed in neutrophils. GSDMD in human neutrophils and monocyte-derived macrophages (MDMs) was detected by western blotting with anti-GSDMD antibody. The purity of highly purified neutrophils (HPNs) was confirmed by Wright-Giemsa staining of cytospin samples. (B) GSDMD expression in undifferentiated and differentiated HL60 cells. (C) Cleavage of human GSDMD (hGSDMD) by human neutrophil lysate. FLAG-hGSDMD was overexpressed in HEK293T cells. Cell lysates containing recombinant FLAG-hGSDMD were incubated with human neutrophil lysate for the times indicated. The positions of the full-length (FL-GSDMD) and ELANE-cleaved N-terminal hGSDMD (hGSDMD-NT) are indicated. (D) Cleavage of mouse GSDMD (mGSDMD) by mouse neutrophil lysate. FLAG-mGSDMD was overexpressed in HEK293T cells and was incubated with mouse neutrophil lysate for the times indicated. (E) hGSDMD cleavage by human neutrophil lysate was mediated by serine proteases. The cleavage of FLAG-hGSDMD by caspase-1 or human neutrophil lysate was conducted as described in Figure 4C in the presence of indicated inhibitors. (F) The cleavage of mGSDMD by mouse neutrophil lysate in the presence of caspase or serine protease inhibitor. (G) The cleavage of hGSDMD by serine proteases. FLAG-hGSDMD was overexpressed in HEK293T cells. Cell lysates containing recombinant FLAG-hGSDMD were incubated with human recombinant caspase 1 (100 units), PR3 (2 μg), ELANE (2 μg), or cathepsin G (2 μg) at 37°C for 30 min in a 6-well plate. The positions of the FL- and ELANE-cleaved hGSDMD are indicated. (H) The cleavage of hGSDMD by human neutrophil lysate in the presence of the indicated number of ELANE-specific inhibitors. (I) The cleavage of mGSDMD by mouse ELANE. FLAG-mGSDMD was overexpressed in HEK293T cells and incubated with the indicated proteases. ELANE enzymatic activity was determined using an ELANE-specific substrate following the manufacturer’s protocol. (J) The cleavage of mGSDMD by ELANE-deficient neutrophil lysate. Disruption of ELANE was confirmed by western blotting with ELANE antibody. (K) The cleavage of mGSDMD by caspase-1/11-deficient neutrophil lysate. (L) Total peritoneal cell and peritoneal neutrophil numbers in E. coli-challenged WT and caspase-1/11-deficient mice. Total neutrophil content in the lavage fluid was calculated by FACS analysis. Data shown at each time point are means ± SDs of four mice. NS, not significant; p > 0.05 versus WT.
Figure 5
Figure 5. Lysosomal Membrane Permeabilization Induces ELANE Release into the Cytosol and the Subsequent GSDMD Cleavage
(A) Neutrophil lysosomal membrane permeabilization (LMP) was assessed using the acridine orange (AO) uptake assay after 24 hr of culture. Shown are representative images and FACS plots of three independent experiments. (B) E. coli-induced LMP. Mouse or human neutrophils were cultured with opsonized E. coli (1:5 ratio) for 30 min. Cells containing ≥5 granules and cells containing <5 granules are calculated. Shown are representative images of three independent experiments. (C) PR3 and ELANE protein expression in whole-cell lysates (WCL) and the cytosolic fraction of fresh and aging neutrophils. Shown are representative blots of three independent experiments. (D) PR3 and ELANE protein expression in neutrophils treated with E. coli. Human and mouse neutrophils were cultured with opsonized E. coli (1:5 ratio) for 60 min. Shown are representative blots of three independent experiments. (E) Spontaneous neutrophil death in the presence of ELANE, caspase-1/4/5-specific inhibitors, or all of these. Human primary neutrophils were isolated and cultured in the presence of ELANE-specific inhibitor sivelestat (1 μg/mL), caspase-1/4/5-specific inhibitor z-WEHD-fmk (10 μM), or all of these for 26 hr. All of the values represent means ± SDs. (F) E. coli-induced neutrophil death in the presence of ELANE inhibitor. Human neutrophils were cultured with opsonized E. coli (1:5 ratio) in the presence of sivelestat (1 μg/mL) for 60 min. All of the values represent means ± SDs of three experiments. (G) In vitro killing of E. coli by aged human neutrophils. Human primary neutrophils were isolated and cultured in the presence of ELANE-specific inhibitor sivelestat (1 μg/mL) for 26 hr. The cultured aged neutrophils were then incubated with E. coli for 1 hr. In vitro bacterial killing capabilities were reflected by the decrease in CFU after indicated incubation periods. All of the values represent means ± SDs of three experiments. *p < 0.05 versus control.
Figure 6
Figure 6. ELANE Cleaves GSDMD Upstream of the Caspase Cleavage Site
(A) Schematic ofGSDMD cleavage by ELANE and the strategy for identifying the cleavage site by mass spectrometry (MS). (B) Recombinant human His-SUMO-GSDMD was incubated with ELANE or human neutrophil lysates at 37°C for 30 min and subjected to SDS-PAGE followed by colloidal blue staining. The FL and ELANE-cleaved GSDMD-NT fragment were trypsin digested and analyzed by MS. (C) Trypsin-digested peptides derived from the FL (blue lines) and ELANE-cleaved (red lines) GSDMD are underlined. The putative ELANE cleavage sites are highlighted. (D) The cleavage of hGSDMD deletion mutants by ELANE. The FLAG-tagged hGSDMD deletion mutants were overexpressed in HEK293T cells. ELANE-mediated hGSDMD cleavage was carried out and analyzed as described in Figure 4C. (E) The cleavage of hGSDMD point mutants by ELANE. Results are representative of four independent experiments. (F) MS analysis of the ELANE cleavage site in hGSDMD was conducted using AspN-digested samples. Top, mass spectrum of oxidized AspN-peptide generated through the cleavage. Bottom, MS/MS spectrum of the corresponding peptide showing the fragment ions detected and used for protein identification. (G) MS analysis identifies C268 as the ELANE cleavage site in hGSDMD. AspN-digested peptides derived from the FL (blue lines) and ELANE-cleaved (red lines) GSDMD are underlined. (H) ELANE- and caspase-1-cleaved hGSDMD at different sites.
Figure 7
Figure 7. ELANE Cleaves GSDMD to Generate a Smaller but still Biologically Active GSDMD-eNT Fragment
(A) Expression of FLAG-tagged FL, ELANE-cleaved (hGSDMD-eNT or 1–268), and caspase-cleaved (hGSDMD-cNT or 1–275) human GSDMD in HEK293T cells. The cells were lysed 24 hr post-transfection. (B) GSDMD protein oligomerization. The cells expressing the indicated hGSDMD protein were lysed with lysis buffer with or without disuccinimidyl suberate crosslinking reagent (1 mg/mL) and incubated at room temperature for 30 min. The reaction was quenched by 0.1 M Tris, pH 7.4. (C) Subcellular localization of recombinant hGSDMD in 293T cells. Shown are representative images of three independent experiments. (D) Cell morphology of transfected cells was observed by bright field microscopy 24 hr post-transfection (see also Movies S1, S2, S3, and S4). PI staining was conducted to assess cell death. Shown are representative images of three independent experiments. (E) Cytotoxicity was measured using a lactate dehydrogenase (LDH) cytotoxicity assay. All of the values represent means ± SDs of three independent experiments.
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References

    1. Adkison AM, Raptis SZ, Kelley DG, Pham CT. Dipeptidyl peptidase I activates neutrophil-derived serine proteases and regulates the development of acute experimental arthritis. J Clin Invest. 2002;109:363–371. - PMC - PubMed
    1. Aglietti RA, Estevez A, Gupta A, Ramirez MG, Liu PS, Kayagaki N, Ciferri C, Dixit VM, Dueber EC. GsdmD p30 elicited by caspase-11 during pyroptosis forms pores in membranes. Proc Natl Acad Sci USA. 2016;113:7858–7863. - PMC - PubMed
    1. Bakele M, Joos M, Burdi S, Allgaier N, Pöschel S, Fehrenbacher B, Schaller M, Marcos V, Kümmerle-Deschner J, Rieber N, et al. Localization and functionality of the inflammasome in neutrophils. J Biol Chem. 2014;289:5320–5329. - PMC - PubMed
    1. Belaaouaj A, McCarthy R, Baumann M, Gao Z, Ley TJ, Abraham SN, Shapiro SD. Mice lacking neutrophil elastase reveal impaired host defense against gram negative bacterial sepsis. Nat Med. 1998;4:615–618. - PubMed
    1. Belaaouaj A, Kim KS, Shapiro SD. Degradation of outer membrane protein A in Escherichia coli killing by neutrophil elastase. Science. 2000;289:1185–1188. - PubMed

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