TABLE 1.

Main ectonucleotidases and ecto-enzymes involved in regulation of purinergic signalling.

Ecto-enzyme	Substrates	Products	Expression	Function	Ref
NTPDase1/CD39	ATP, ADP	ADP, AMP	Monocytes, DCs, NK cells, Treg cells, ECs	Converts ATP/ADP to AMP	Mizumoto et al. (2002); Deaglio et al. (2007); Deaglio and Robson (2011); Kishore et al. (2018)
NAD glycohydrolase/CD38	NAD+, cADPR	cADPR, AMP	Activated T and B cells, plasma cells, DCs	Converts NAD+ to cADP ribose	Linden et al. (2019)
NPP1	ATP, ADP, NAD+	AMP	Inflammatory cells	Production of AMP starting from different substrates	Wang et al. (2018a)
NPP2	LPC, ATP	LPA, AMP	Inflammatory and tumor cells	Converts LPC to LPA	Sevastou et al. (2013)
NT5E/CD73	AMP	Adenosine	Follicular DCs, ECs, T and B lymphocytes	Converts AMP to adenosine	Thomson et al. (1990); Bono et al. (2015); Antonioli et al. (2016)
ADA	Adenosine	Inosine	DCs and lymphocytes	Converts adenosine to inosine	Franco et al. (1998); Desrosiers et al. (2007)

LPC, Lysophosphatidylcholine; LPA, lysophosphatidic acid; ECs, endothelial cells; DCs, dendritic cells; ADA, adenosine deaminase.