| First Author | Wang R | Year | 2021 |
| Journal | Front Cell Dev Biol | Volume | 9 |
| Pages | 772669 | PubMed ID | 34805179 |
| Mgi Jnum | J:366226 | Mgi Id | MGI:6827875 |
| Doi | 10.3389/fcell.2021.772669 | Citation | Wang R, et al. (2021) Programmed Cell Death Ligand 1 Is Enriched in Mammary Stem Cells and Promotes Mammary Development and Regeneration. Front Cell Dev Biol 9:772669 |
| abstractText | Programmed cell death ligand 1 (PD-L1) is widely expressed in a variety of human tumors, and inhibition of the PD-L1/PD-1 pathway represents one of the most promising therapy for many types of cancer. However, the physiological function of PD-L1 in tissue development is still unclear, although PD-L1 mRNA is abundant in many tissues. To address this puzzle, we investigated the function of PD-L1 in mammary gland development. Interestingly, we found that PD-L1 is enriched in protein C receptor (Procr)-expressing mammary stem cells (MaSCs), and PD-L1-expressing mammary basal cells (PD-L1(+) basal cells) exhibit robust mammary regeneration capacity in transplantation assay. The lineage tracing experiment showed that PD-L1(+) cells can differentiate into all lineages of mammary epithelium cells, suggesting that PD-L1(+) basal cells have the activities of MaSCs. Furthermore, PD-L1 deficiency significantly impairs mammary development and reduces mammary regeneration capacity of mammary basal cells, suggesting that PD-L1 is not only enriched in MaSCs but also improves activities of MaSCs. In summary, these results demonstrated that PD-L1 is enriched in MaSCs and promotes mammary gland development and regeneration. Mechanistically, our data indicated that PD-L1 expression is induced by continuous activation of Wnt/ss-catenin signaling. In conclusion, these results demonstrated that PD-L1 is a marker of MaSCs, and PD-L1 is essential for mammary development. Our study provides novel insight into the physiological functions of PD-L1 in tissue development. |
