Thrombospondin-1 induced programmed death-ligand 1-mediated immunosuppression by activating the STAT3 pathway in osteosarcoma.

ABSTRACT: Thrombospondin-1 (TSP1) is generally assumed to suppress the growth of osteosarcoma through inhibiting angiogenesis; however, it is unclear whether TSP1 could affect the antitumor immunity against osteosarcoma. We aimed to explore the immune-related tumor-promoting effects of TSP1 and decipher its underlying mechanism. First, we identified that TSP1 regulated programmed death-ligand 1 (PD-L1) expression, which was related to the CD8⁺ T cells anergy in osteosarcoma cells. The exact role of PD-L1 in the immunosuppressive effect of TSP1 was then further confirmed by the addition of the PD-L1 neutralizing Ab. With the addition of PD-L1 neutralizing Abs during cocultivation, the inhibition of CD8⁺ T cells was abolished to a certain extent. Further mechanistic investigation

SUBMITTER: Liu Z 

PROVIDER: S-EPMC8819289 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature