Natural killer cells in cancer biology and therapy

Table 1 Key mediators of NK cells

Classification	Mediator	Host ligand	Ref.
NK cell activator
MHC-I specific receptor	KIR2DS1, 2DS3, 3DS5	MHC I	[28]
	Ly49c, Ly49i	MHC I	[29]
	NKp80	MHC I	[30]
	NKG2C, NKG2E	MHC I	[31]
MHC-I related receptor	NKG2D	MICA, MICB, ULBPs	[13]
MHC-I non-related receptor	DNAM1	Nectin-2, CD155	[32]
	NKp46 (NCR1)	HS GAGs, CFP	[33]
	NKp44 (NCR2)	HS GAGs, MLL5, NKp44L, PCNA, BAT3, PDGF-DD, Nidogen-1	[34]
	NKp30 (NCR3)	HS GAGs, B7-H6, Galectin-3	[35]
	Nkp65	Keratinocyte-associated C-type lectin	[36]
	LFA-1 (αLβ2 integrin)	Intercellular cell adhesion molecule 1	[37, 38]
	α4 integrin	Vascular cell adhesion molecule 1	[39]
	CD16	Fc-γ	[40, 41]
	CD2	CD581	[41]
	TLR3	Microbial constituents, adjuvant	[42]
	TLR9	CpG	[43]
NK cell inhibitor
MHC-I specific receptor	KIR3DL1	MHC I	[44]
	KIR2DL3, 2DL1	MHC I	[45]
	NKG2A	MHC I	[46]
	KLRB1, LLT1	MHC I	[47]
	LILRB1, LILRB2	MHC I	[48]
MHC-I non-related receptor	KLRG1	E-, N-, and R- cadherins	[49]
	siglec-3, siglec-7, siglec-9	Sialic acid	[50, 51]
	CEACAM1	CEACAM1, CEACAM5	[52]
	2B4 (CD244)	CD48	[53]
	IRp60	Phosphatidylserine	[54]
	LAIR1	Ep-CAM	[55]
	CD96	CD155	[56]
	CD73	Antibodies	[57]
	PD-1	PD-L1	[58]
	TIGIT	CD155	[20]
	NKR-P1B	Clr-b	[59]
	LAG3	MHC-II	[60]

Abbreviations: MHC major histocompatibility complex, KIR killer cell immunoglobulin-like receptor, MIC MHC class I chain-related, ULBP UL16-binding protein 1, DNAM1 DNAX accessory molecule 1, NCR natural cytotoxicity receptor, HS GAGs heparan sulfate glycosaminoglycans, CFP complement factor P, MLL5 mixed-lineage leukemia protein-5, PCNA proliferating cell nuclear antigen, BAT3 HLA-B-associated transcript 3, PDGF-DD platelet-derived growth factor-DD, LFA-1 lymphocyte function-associated antigen-1, TLR toll-like receptor, KLR killer cell lectin-like receptor, LLT1 lectin-like transcript 1, LILR leukocyte immunoglobulin-like receptor, Siglec sialic acid-binding immunoglobulin-like lectin, CEACAM carcinoembryonic antigen-related cell-adhesion molecule, IRp60 inhibitory receptor protein 60, LAIR1 leukocyte-associated immunoglobulin-like receptor 1, Ep-CAM epithelial cellular adhesion molecule, PD-1 programmed cell death protein 1, TIGIT T-cell immunoreceptor with Ig and ITIM domains, LAG3 lymphocyte activation gene 3

ISSN: 1476-4598