Armed for destruction: formation, function and trafficking of neutrophil granules
Neutrophils respond nearly instantly to infection, rapidly deploying a potent enzymatic and chemical arsenal immediately upon entering an infected site. This capacity for rapid and potent responses is endowed by stores of antimicrobial proteins contained in readily mobilizable granules. These granules contain the proteins necessary to mediate the recruitment, chemotaxis, antimicrobial function and NET formation of neutrophils. Four granule types exist, and are sequentially deployed as neutrophils enter infected sites. Secretory vesicles are released first, enabling recruitment of neutrophils out of the blood. Next, specific and gelatinase granules are released to enable neutrophil migration and begin the formation of an antimicrobial environment. Finally, azurophilic granules release potent antimicrobial proteins at the site of infection and into phagosomes. The step-wise mobilization of these granules is regulated by calcium signaling, while specific trafficking regulators and membrane fusion complexes ensure the delivery of granules to the correct subcellular site. In this review, we describe neutrophil granules from their formation through to their deployment at the site of infection, focusing on recent developments in our understanding of the signaling pathways and vesicular trafficking mechanisms which mediate neutrophil degranulation.
KeywordsNeutrophil Degranulation Granulopoiesis Calcium GTPase Vesicular traffic
Complement receptor 3
Dedicator of cytokinesis protein 2
GTPase activating protein
Guanine exchange factor
G protein-coupled receptor
Immunoreceptor tyrosine-based activation motif
Neutrophil extracellular trap
Specific granule deficiency
Vesicle-associated membrane protein.
The work in B.H.’s laboratory is supported by an operating grant from the Canadian Institutes for Health Research (MOP-123419), discovery grant #418194 from the Natural Sciences and Engineering Council of Canada, and an Ontario Ministry of Research and Innovation Early Researcher Award. C.Y. is a Vanier Scholar and holds a Canadian Institutes for Health Research MD/PhD Studentship.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Biesemann A, Gorontzi A, Barr F, Gerke V (2017) Rab35 regulates evoked Exocytosis of endothelial Weibel-Palade bodies. J Biol Chem. https://doi.org/10.1074/jbc.M116.773333
- Breton-Gorius J, Mason DY, Buriot D et al (1980) Lactoferrin deficiency as a consequence of a lack of specific granules in neutrophils from a patient with recurrent infections. Detection by immunoperoxidase staining for lactoferrin and cytochemical electron microscopy. Am J Pathol 99:413–428PubMedPubMedCentralGoogle Scholar
- Clemens RA, Chong J, Grimes D et al (2017) STIM1 and STIM2 cooperatively regulate mouse neutrophil store operated calcium entry and cytokine production. Blood. https://doi.org/10.1182/blood-2016-11-751230
- Fällman M, Gullberg M, Hellberg C, Andersson T (1992) Complement receptor-mediated phagocytosis is associated with accumulation of phosphatidylcholine-derived diglyceride in human neutrophils. Involvement of phospholipase D and direct evidence for a positive feedback signal of protein kinase. J Biol Chem 267:2656–2663PubMedGoogle Scholar
- Hossain M, Qadri SM, Xu N et al (2015) Endothelial LSP1 modulates Extravascular Neutrophil Chemotaxis by regulating nonhematopoietic vascular PECAM-1 expression. J Immunol. https://doi.org/10.4049/jimmunol.1402225
- Johnson JL, Monfregola J, Napolitano G et al (2012) Vesicular trafficking through cortical actin during exocytosis is regulated by the Rab27a effector JFC1/Slp1 and the RhoA-GTPase-activating protein gem-interacting protein. Mol Biol Cell 23:1902–1916. https://doi.org/10.1091/mbc.E11-12-1001 PubMedPubMedCentralCrossRefGoogle Scholar
- Johnson JL, Ramadass M, He J et al (2016b) Identification of Neutrophil Exocytosis inhibitors (Nexinhibs), small molecule inhibitors of Neutrophil Exocytosis and inflammation: DRUGGABILITY OF THE SMALL GTPase Rab27a. J Biol Chem 291:25965–25982. https://doi.org/10.1074/jbc.M116.741884 PubMedPubMedCentralCrossRefGoogle Scholar
- Khanna-Gupta A, Zibello T, Sun H et al (2003) Chromatin immunoprecipitation (ChIP) studies indicate a role for CCAAT enhancer binding proteins alpha and epsilon (C/EBP alpha and C/EBP epsilon ) and CDP/cut in myeloid maturation-induced lactoferrin gene expression. Blood 101:3460–3468. https://doi.org/10.1182/blood-2002-09-2767 PubMedCrossRefGoogle Scholar
- Kjeldsen L, Bainton DF, Sengeløv H, Borregaard N (1993) Structural and functional heterogeneity among peroxidase-negative granules in human neutrophils: identification of a distinct gelatinase-containing granule subset by combined immunocytochemistry and subcellular fractionation. Blood 82:3183–3191PubMedGoogle Scholar
- Kudo M, Brem MS, Canfield WM (2006) Mucolipidosis II (I-cell disease) and mucolipidosis IIIA (classical pseudo-hurler polydystrophy) are caused by mutations in the GlcNAc-phosphotransferase alpha / beta -subunits precursor gene. Am J Hum Genet 78:451–463. https://doi.org/10.1086/500849 PubMedPubMedCentralCrossRefGoogle Scholar
- Kumar TS, Scott JX, Raghupathy P, Moses PD (2005) Mucolipidosis II (I - cell disease). J Postgrad Med 51:232–233Google Scholar
- Maher RJ, Cao D, Boxer LA, Petty HR (1993) Simultaneous calcium-dependent delivery of neutrophil lactoferrin and reactive oxygen metabolites to erythrocyte targets: evidence supporting granule-dependent triggering of superoxide deposition. J Cell Physiol 156:226–234. https://doi.org/10.1002/jcp.1041560203 PubMedCrossRefGoogle Scholar
- Mollinedo F, Martín-Martín B, Calafat J et al (2003) Role of vesicle-associated membrane protein-2, through Q-soluble N-ethylmaleimide-sensitive factor attachment protein receptor/R-soluble N-ethylmaleimide-sensitive factor attachment protein receptor interaction, in the exocytosis of specific and tertiary. J Immunol 170:1034–1042PubMedCrossRefGoogle Scholar
- Numata A, Shimoda K, Kamezaki K et al (2005) Signal transducers and activators of transcription 3 augments the transcriptional activity of CCAAT/enhancer-binding protein alpha in granulocyte colony-stimulating factor signaling pathway. J Biol Chem 280:12621–12629. https://doi.org/10.1074/jbc.M408442200 PubMedCrossRefGoogle Scholar
- Rørvig S, Østergaard O, Heegaard NHH, Borregaard N (2013) Proteome profiling of human neutrophil granule subsets, secretory vesicles, and cell membrane: correlation with transcriptome profiling of neutrophil precursors. J Leukoc Biol 94:711–721. https://doi.org/10.1189/jlb.1212619 PubMedCrossRefGoogle Scholar
- Suzaki E, Kobayashi H, Kodama Y et al (1997) Video-rate dynamics of exocytotic events associated with phagocytosis in neutrophils. Cell Motil Cytoskeleton 38:215–228. https://doi.org/10.1002/(SICI)1097-0169(1997)38:3<215::AID-CM1>3.0.CO;2-4 PubMedCrossRefGoogle Scholar
- Wilson NK, Timms RT, Kinston SJ et al (2010) Gfi1 expression is controlled by five distinct regulatory regions spread over 100 kilobases, with Scl/Tal1, Gata2, PU.1, erg, Meis1, and Runx1 acting as upstream regulators in early hematopoietic cells. Mol Cell Biol 30:3853–3863. https://doi.org/10.1128/MCB.00032-10 PubMedPubMedCentralCrossRefGoogle Scholar