Table 1
|
Structures, expression patterns and receptors of B7 ligands |
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| Ligand name (alternative names) |
Structure |
Protein expression pattern in lymphoid cells* |
mRNA expression in non-lymphoid tissues or cells |
Receptor |
Function of ligand-receptor interaction |
|
|
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| B7.1 (CD80) |
 |
Induced in T, B, DCs, and monocytes |
Not detected |
CD28 CTLA-4 (CD152) |
Costimulation Coinhibition |
| B7.2 (CD86) |
|
Constitutive and upregulated upon activation in B, DCs, and monocytes; induced in T |
Not detected |
CD28 CTLA-4 (CD152) |
Costimulation Coinhibition |
| ICOS-L (GL-50, B7 h, B7RP-1, B7H-2) |
|
Constitutive in B, DCs, macrophages, and a subset of T |
Lung, liver, kidney, and testes |
ICOS |
Costimulation |
| PD-L1 (B7-H1) |
|
Constitutive and upregulated upon activation in B, DCs, and monocytes; induced in T |
Placenta, heart, pancreas, lung, liver, and tumor cells (carcinomas and melanomas) |
PD-1 Unknown? |
Coinhibition Costimulation |
| PD-L2 (B7-DC) |
|
Induced in DCs and monocytes |
Heart, placenta, lung, liver keratinocytes, and epithelial cells |
PD-1 Unknown? |
Coinhibition Costimulation |
| B7-H4 (B7x, B7S1) |
 |
Induced in T, B, NK, DCs, and monocytes |
Placenta, uterus, testis, kidney, lung, heart, and brain |
Unknown |
Coinhibition |
| B7-H3 |
 |
Induced in T, B, DCs, and monocytes |
Heart, kidney, testes, lung, liver, pancreas, prostate, colon, and osteoblasts |
Unknown Unknown |
Costimulation Coinhibition |
|
*Abbreviations: B, B cells; DCs, dendritic cells; NK, natural killer cells; T, T cells; Unknown?, postulated receptor. | |||||
Collins et al. Genome Biology 2005 6:223 doi:10.1186/gb-2005-6-6-223 |
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