Table 1 A summary of immune checkpoint molecules

CTLA-4

Cytotoxic T lymphocyte-associated protein-4

CD152

CD80 (B7-1)

CD86 (B7-2)

T cells

^5,139

PD-1

Programmed cell-death

protein-1

CD279

PD-L1 (B7-H1 or CD274)

PD-L2 (B7-DC or CD273)

T cells, NKT cells, B cells,

monocytes, Langerhans’ cells

^16,140

LAG-3

Lymphocyte activation gene-3

CD223

MHC-II

FGL1

galectin-3 (LGALS3)

LSECtin

α-synuclein

T cells, B cells,

Tregs,

NK cells,

NKT cells,

pDCs

^5,141,142

TIGIT

T-cell immunoglobulin

and ITIM domain

WUCAM Vstm3

Vsig9

CD155 (PVR, Necl-5)

CD112 (nectin-2, PRR2, PVRL2)

T cells, Tregs, NK cells,

^143,144,145

TIM-3

T-cell immunoglobulin

and mucin-domain containing-3

HAVCR2

CD366

Galectin-9

Ceacam-1

HMGB-1

PtdSer

T cells, Tregs, DCs,

NK cells, monocytes,

macrophages

^{5,18,144,145,146}

BTLA

B and T cell

lymphocyte attenuator

CD272

HVEM

B cells, T cells,

macrophages, DCs

^147,148

VISTA

V-domain Ig

suppressor of

T cell activation

PD-1H

DD1α

Gi24

Dies1

B7-H5

VSIG-3

APCs, T cells, Tregs

^5,149

B7-H3

B7 homolog 3 protein

CD276

IL20RA

TLT2 (putative)

T cells, B cells, APCs, NK cells,

DCs, monocytes, fibroblasts,

epithelial cells, tumor cells

^{5,145,150,151,152,153}

B7-H4

B7 homolog 4 protein

VTC1 B7x B7S1

unknown

T cells, B cells, monocytes, DCs

^145,154,155

KIR

Killer-cell immunoglobulin-like receptor

CD158

MHC class I molecules

NK cells, T cells

^111,156

CD160

Cluster of differentiation 160

–

HVEM

NK cells, T cells,

intraepithelial lymphocytes

¹⁵⁷

CD73

Cluster of differentiation 73

ecto-5’-

nucleotidase

Dephosphorylating extracellular AMP to generate adenosine

Tumor cells, Th cells, Tregs,

T cells, B cells, macrophages, DCs

^158,159

CD96

Cluster of differentiation 96

–

CD111

CD155

T cells, NK cells, NKT cells

^160,161