Ontology highlight
ABSTRACT: Background
Osteosarcoma (OS) is a rare cancer with a bimodal age distribution that peaks in children and young adults. It has been shown that the expression of programmed cell death protein 1 (PD-1) and programmed death ligand-1 (PD-L1) on tumor-infiltrating immune cells negatively correlates with prognosis of OS patients. However, a comprehensive assessment of the tumor-infiltrating immune cells in OS and their function has not been performed.Methods
CD8+ T cells were isolated from biopsy tissue samples collected from OS patients and control subjects. Mass cytometry, Treg suppression assay, mixed lymphocyte reaction assay, and effector T cell functional assay were performed to analyze the function of tumor-infiltrating T cells. A xenograft metastasis model was established in BALB/c nude mice.Results
Macrophages and CD3+ T cells comprised most of the tumor-infiltrating immune cells in OS, with a disproportionately higher number of helper CD4+ T cells than effector CD8+ T cells. Whereas the tumor-infiltrating regulatory T cells were functionally intact, the CD8+ T cells showed increased expression of the immune checkpoint receptor (ICR) PD-1 and T cell immunoglobulin and mucin-domain containing 3 (TIM3) and were functionally inactive. TIM3 blockade using a monoclonal antibody restored the T cell alloreactive function of the CD8+ T cells ex vivo. TIM3 blockade in a xenograft model of OS impaired tumor growth in vivo. TIM3 blockade decreased the number of tumor-infiltrating CD4+ T cells while increasing the numbers and functional activation of tumor-infiltrating CD8+ T cells in vivo.Conclusions
These results highlight that TIM3 blockade might be a viable therapeutic option and should be tested in additional preclinical models.
SUBMITTER: Sun CY
PROVIDER: S-EPMC8506720 | biostudies-literature | 2021 Sep
REPOSITORIES: biostudies-literature
Sun Cheng-Ying CY Zhang Zhe Z Tao Lei L Xu Fei-Fei FF Li Hui-Yuan HY Zhang Hui-Yu HY Liu Wei W
Annals of translational medicine 20210901 18
<h4>Background</h4>Osteosarcoma (OS) is a rare cancer with a bimodal age distribution that peaks in children and young adults. It has been shown that the expression of programmed cell death protein 1 (PD-1) and programmed death ligand-1 (PD-L1) on tumor-infiltrating immune cells negatively correlates with prognosis of OS patients. However, a comprehensive assessment of the tumor-infiltrating immune cells in OS and their function has not been performed.<h4>Methods</h4>CD8<sup>+</sup> T cells were ...[more]