Page 6 - X. Stem cell biology

[X. Stem cell biology-5]

Immunomodulatory effect and maintenance of

differentiation via PD1/PDL-1 axis in osteoblasts

differentiated from hADMSCs

Seung-Cheol Lee¹, Min Kyoung Shin¹, Jung-Suk Sung¹˙*

¹Department of Life Science, Dongguk University-Seoul, Goyang 10326, South Korea

Human adipose tissue derived mesenchymal stem cells (hADMSCs) are promising candidate in stem cell therapy.
However the improved immunomodulatory effect and efficacy on differentiation potential are required to pass over
limitation of the therapy. Recent studies reported that MSCs secrete PD-L1 mediating T cell mediated

immunosuppression. In this study, we showed that the expression level of Programmed cell death protein 1 (PD-1),
was increased in the osteoblasts when compared with hADMSCs. Interestingly, the expression levels of pro-

inflammatory cytokines (IL-6, TNF-α, IL-1β) were decreased in differentiated osteoblasts co-cultured with hADMSCs,
attenuating the expression levels by PD1/PD-L1 pathway inhibition. IL-6 induction mediated by TNF-α and IL-1β is

known for effect on promoting osteoclastogenesis in osteoblasts. We showed that osteoblasts co-cultured with
hADMSCs expressed higher levels of osteogenic markers (RUNX2, OCN, ALP) compared with non-co-cultured

osteoblasts. We suggest here that PD1/PDL-1 axis mediates inhibition of pro-inflammatory cytokine expressions
and osteoclastogenesis in osteoblasts co-cultured with hADMSCs. [This work was supported by the National

Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2017R1D1A1B03030983)]