Table 1.

Overview of publications studying the biological function of neutrophil-derived EVs (extracellular vesicles).

	PMN-EV Induction Stimulus	Target	Effect	PMN Purity	PMN Viability	EV Isolation Method	EV Characterization Method	EV Diameter [nm]	EV Storage	Ref.
Unstimulated	Spontaneous release	HMDM	Bacterial killing ↓	? (nuclear morphology analyzed with light microscopy)	95% (Trypan Blue)	DC	FC, EM	50–300	−80 °C	[85]
		PMN, HUVEC, plasma	Anti-inflammatory, PMN ROS production ↓, pro-coagulant	>95%	?	DC + F	FC, DLS, NTA, EM	80–1000	none	[86]
	Apoptosis induction	none	No pro-inflammatory effect	?	n/a	no isolation	FC	?	?	[87]
		Monocytes, HMDM	Mostly anti-inflammatory, but IL-10 production of HMDM ↓	>90% (CD15 FC)	n/a	no isolation	FC	?	−70 °C	[88]
		PMN	ROS production ↓, Leishmania killing ↓	>99.9% (Diff Quik)	n/a	no isolation	FC	?	n/a	[89]
		Th cells	Anti-inflammatory	?	n/a	DC + F	FC, NTA	100–400	?	[90]
		HMDM	Anti-inflammatory	?	n/a	no isolation	FC	?	?	[91]
		PMN, HUVEC, plasma	PMN ROS production delayed, pro-coagulant	>95%	?	DC + F	FC, DLS, NTA, EM	80–1000	none	[86]
Bacterial byproducts	fMLP	HMDM	Anti-inflammatory	?	?	DC + F	?	?	−80 °C	[92]
		MoDC	Anti-inflammatory, anti-phagocytic	?	?	DC + F	FC	?	−80 °C	[93]
		HMDM	Anti-inflammatory	?	?	DC + F	none	?	−80 °C	[94]
		Peritoneal macrophages	Anti-inflammatory	?	?	DC	FC, EM	50–500	?	[95]
		NK cells	Anti-inflammatory	95% or 99% (FC)	?	DC	FC	200–1000	?	[96]
		PMN, systemic	PMN recruitment ↓, PMN-EC interaction ↓	?	?	DC	FC	?	?	[97]
		HUVEC	Pro-inflammatory, TF expression ↑	?	?	F or DC	FC	?	?	[98]
		HUVEC	Pro-inflammatory	?	?	DC + F	FC	?	?	[99]
		Human coronary endothelial cells	Pro-inflammatory, pro-migratory	?	?	DC + dialysis	FC, TRPS—human, NTA—mouse	280 (human), 165 (mouse)	?	[100]
		BMEC	Vascular permeability ↑	?	?	DC	FC, NTA	100–300	?	[101]
		IEC	Delivers pro-inflammatory miR content, genomic instability, impaired wound healing	Human: ?, Mouse: 85–90%	?	DC	EM	?	?	[102]
		PLT	Arachidonic acid transfer to PLT, causing TXA2 release and subsequent pro-inflammatory EC activation	?	?	ExoQuick-TC kit	?	?	?	[103]
		HUVEC	Non-adherent PMN-derived EVs: anti-inflammatory, vasoprotective. Adherent PMN-derived EVs: pro-inflammatory, vasoreactive	?	?	DC	FC	?	−80 °C	[104]
		HMDM	Pro-inflammatory, bacterial killing ↑	>98%	>98%	DC	FC, NTA, EM	100–200	4 °C <24 h	[105]
		HMDM, PMN, systemic	Pro- and anti-inflammatory, bacterial killing ↑, PMN and macrophage ROS production ↑	?	?	DC	FC	2000–3000	−80 °C	[106]
		ECM	Neutrophil elastase-dependent degradation of ECM	?	>95% (Trypan Blue)	DC	FC, NTA, EM	100	−80 °C or fresh	[107]
		IEC	Disruption of epithelial intercellular adhesion, enhanced transepithelial migration	Human: ?, Mouse: 85–90%	?	DC	FC, EM	100–800	?	[108]
		Vascular permeability	Maintaining the integrity of the microvascular barrier	?	?	no isolation	FC	?	?	[109]
		S. aureus	Binding to opsonized bacteria	>98%	>99% before and after stimulation (Trypan Blue)	DC + F	EM	?	?	[110]
	fMLP or fMLP + LatrB	IEC	Inhibition of epithelial wound healing via MPO delivery	Human: ?, Mouse: 85–90%	?	no isolation	FC, EM	600	?	[111]
	GM-CSF + (?) fMLP	PMN	Pro-inflammatory	?	?	DC + F	FC, EM	50–120 (purified from 50–500)	?	[112]
	fMLP + LPS	PMN, HMDM	ROS production ↑	?	?	DC	FC	?	?	[113]
	LPS	P1EC, artery rings	Pro-inflammatory, oxidative stress ↑, TF expression ↑	n/a (splenocytes)	?	DC	TRPS	200–500	?	[114]
		Airway smooth muscle cells	Proliferation	99.5% (Cytospin slide + Protocol Hema 3 staining)	97.75% (ADAM cell counter)	Size-exclusion chromatography	DLS, EM	30–80	−80 °C	[115]
		PLT	Platelet activation and co-aggregation with PMN, delivery of PAF receptor	?	?	DC	none	?	?	[116]
		PLT	Platelet activation	?	?	DC + F	FC	<1000	−80 °C	[117]
Endogenous pro-inflammatory mediators	TNFα	HDMD, joints, macrophage-FLS co-culture system	Anti-inflammatory	?	?	DC	FC, NTA	70–400	?	[118]
		IEC	Delivers pro-inflammatory miR content, genomic instability, impaired wound healing	Human: ?, Mouse: 85–90%	?	DC	EM	?	?	[108]
		Embryonic kidney cells	Transfer of kinin B1-receptors, calcium influx	?	?	DC	FC, EM	150	−80 °C	[119]
	IFN-γ	IEC	Delivers pro-inflammatory miR content, genomic instability, impaired wound healing	Human: ?, Mouse: 85–90%	?	DC	EM	?	?	[108]
		PMN, HUVEC	Mainly pro-inflammatory and pro-migratory, but reduced increase in EC permeability upon LPS treatment	n/a (stimulation in whole blood)	n/a (stimulation in whole blood)	? (DC)	FC	?	?	[120]
	GM-CSF	PMN, HUVEC	Mainly pro-inflammatory and pro-migratory, EC ROS production ↑, but reduced increase in EC permeability upon LPS treatment	n/a (stimulation in whole blood)	n/a (stimulation in whole blood)	? (DC)	FC	?	?	[120]
	C5a	HMDM	Anti-inflammatory	?	?	DC + F	none	?	−80 °C	[94]
		NK	Anti-inflammatory	95% or 99% (FC)	?	DC	FC	200–1000	?	[96]
		PMN, whole blood	Pro-inflammatory, ROS production ↑, MPO release ↑	?	?	DC	FC	300–1000	−80 °C	[121]
	PAF	PMN, systemic	PMN recruitment ↓, PMN-EC interaction ↓	?	?	DC	FC	?	?	[97]
		PLT	Platelet activation	?	?	DC + F	FC	<1000	−80 °C	[117]
	IL-8	NK	Anti-inflammatory	95% or 99% (FC)	?	DC	FC	200–1000	?	[96]
	CXCL-2	Vascular permeability	Maintaining the integrity of the microvascular barrier	?	?	no isolation	FC	?	?	[109]
Pathogens	M. tuberculosis	HMDM	Bacterial killing ↓	?, but nuclear morphology analyzed with light microscopy	95% (Trypan Blue)	DC	FC, EM	50–300	−80 °C	[85]
	M. tuberculosis	HMDM	Pro-inflammatory, ROS production ↑, autophagy ↑, bacterial killing ↑	>98%	>98%	DC	FC, NTA, EM	100–700	4 °C <24h	[105]
	Ops. A. fumigatus	A. fumigatus	Antifungal effect	>95%	>98%	DC + F	FC, NTA, EM	?	−80 °C or fresh	[122]
	P. aeruginosa	P. aeruginosa	Antibacterial effect	?	?	no isolation	none	?	?	[123]
	Ops. S. aureus	Ops. and non-ops. S. aureus, E. coli	Binding to bacteria, antibacterial effect	>95%	80–85% (EB)	DC + F	FC, DLS, EM	100, 200–800	?	[124]
	Ops. zymosan	S. aureus, E. coli	Antibacterial effect	>95%	?	DC + F	FC	?	?	[125]
		PMN, HUVEC, plasma	Pro-inflammatory, PMN ROS production ↑	>95%	?	DC + F	FC, DLS, NTA, EM	80–1000	none	[86]
Pharmacological stimuli	PMA	MoDC	Anti-inflammatory, Th2 polarization	?	?	DC	FC, DLS	50–600	−80 °C	[126]
		HMDM	Pro-inflammatory	>98%	>98%	DC	FC, NTA, EM	100–300	4 °C <24 h	[105]
		IEC	Inhibition of epithelial wound healing via MPO delivery	Human: ?, Mouse: 85–90%	?	DC	FC, EM	600	?	[111]
		S. aureus	Binding to opsonized bacteria	>98%	>99% before and after stimulation (Trypan Blue)	DC + F	EM	?	?	[110]
		Plasma, NET	Pro-coagulant (intrinsic), NET-binding	?	?	no isolation	FC, EM	?	?	[127]
		PLT	Platelet activation	?	?	DC + F	FC	<1000	−80 °C	[117]
	PMA + A23187	P1EC, artery rings	Pro-inflammatory, oxidative stress ↑, TF expression ↑	n/a (splenocytes)	?	DC	TRPS	200–500	?	[114]
	A23187	HUVEC	MPO-mediated cytotoxicity	>90% (FC CD66b)	?	DC	FC, EM	<1000	4 °C	[128]
	Ionomycin	S. aureus	Binding to opsonized bacteria	>98%	>99% before and after stimulation (Trypan Blue)	DC + F	EM	?	?	[110]
	L-NAME	PMN	Pro-migratory	>97% (hemocytometer)	>95% (Trypan Blue)	DC	FC, EM	?	?	[129]
Pathophysiological environment	Sepsis	THP-1	Pro-inflammatory, pro-phagocytic	n/a (peritoneal and BAL EVs)	n/a (peritoneal and BAL EVs)	C	FC	300–1100	?	[130]
		HUVEC, Plasma, ops. S. aureus	Pro-inflammatory, pro-coagulant, binding to ops. bacteria	>95% (FC)	?	DC	FC, NTA	50–800	?	[131]
		Ops. and non-ops. S. aureus, E. coli	Binding to bacteria	n/a (plasma EVs)	n/a (plasma EVs)	DC + F	FC	?	?	[124]
	Sepsis + LL37	E. coli	Antibacterial effect	90% (Giemsa)	?	DC	FC	500–1000	−80 °C	[132]
	Sepsis + thioglycolate i.p.	Peritoneal macrophages, systemic	Pro- and anti-inflammatory, bacterial clearance ↓, mortality ↑	n/a (peritoneal EVs)	n/a (peritoneal EVs)	DC	FC	?	?	[133]
	Cystic fibrosis/primary ciliary dyskinesia	Airways	Pro-inflammatory	n/a (sputum EVs)	n/a (sputum EVs)	DC	FC	?	4 °C	[134]
	Pancreatitis	Pancreas acinar cells, systemic	Pro-inflammatory, tissue injury ↑	n/a (pancreatic EVs)	n/a (pancreatic EVs)	DC	EM	?	n/a (pancreatic EVs)	[135]
	ANCA vasculitis	none	Pro-coagulant (extrinsic)	?	?	DC	FC	?	?	[136]
	TNFα + ANCA	HUVEC	Pro-inflammatory, pro-coagulant, ROS production ↑	?	?	DC	FC	?	Frozen (no temp. data)	[137]
	Rheumatoid arthritis + TNFα	HDMD, joints, macrophage-FLS co-culture system	Anti-inflammatory	?	?	DC	FC, NTA	70–400	?	[118]
	MSU i.p.	Peritoneal macrophages	Anti-inflammatory	n/a (peritoneal EVs)	n/a (peritoneal EVs)	DC	FC, EM	50–500	?	[95]
	Gout	Peritoneal macrophages	Anti-inflammatory	n/a (synovial EVs)	n/a (synovial EVs)	DC	FC, EM	50	?	[95]
	acLDL	Human coronary endothelial cells	Pro-inflammatory, pro-migratory	?	?	DC + dialysis	FC, TRPS—human, NTA—mouse	280 (human), 165 (mouse)	?	[100]
	Hyperglycemia	None	Release of EVs carrying IL-1β	?	>78% after EV isolation (Trypan Blue)	no isolation	FC	300–1000	?	[138]

Abbreviations of Table 1. ‘?’: not communicated; n/a: not applicable; LatrB: Latrunculin B; Ops.: opsonized; MSU: monosodium urate; i.p.: intraperitoneal; HMDM: human monocyte derived macrophage; HUVEC: human umbilical vein endothelial cell; MoDC: monocyte derived dendritic cell; NK: natural killer; BMEC: brain microvascular endothelial cell; IEC: intestinal epithelial cell; PLT: platelet; ECM: extracellular matrix; P1EC: primary porcine endothelial cell; FLS: fibroblast-like synoviocyte; ROS: reactive oxygen species; EC: endothelial cell; MPO: myeloperoxidase; FC: flow cytometry; EM: electron microscopy; DLS: dynamic light scattering; NTA: nanoparticle tracking analysis; TRPS: tunable resistive pulse sensing; DC: differential centrifugation; F: filtration.