Degradation-resistant implanted biomaterials establish an immunosuppressive microenvironment that induces T cell exhaustion by recruiting myeloid cells

Abstract

Implanted biomaterials have transformed healthcare and the treatment of injury and disease, but their influence on the local immune landscape remains unclear. Here we discovered that degradation-resistant titanium-based implants establish an immunosuppressive microenvironment by recruiting myeloid cells, including monocytes, macrophages, neutrophils, and myeloid-lineage dendritic cells. Unlike normal tissues, the tissues nearby implants exhibit an chronic inflamed and immunosuppressive status characterised by myeloid-rich, T cell-exhaustion gene signature by single-cell RNA sequencing. Vitamin C treatment provides an effective strategy to rescue the immunosuppressive microenvironment, which can be used as a regular supplement to reduce the risk of malignant cell survival around the implants.

Graphical abstract

In this study, we reported a phenomenon that foreign refractory-degradable implants can establish an immunosuppressive microenvironment via recruitment of myeloid cells to induce T cell exhaustion, resulting in the promoted tumour growth at the injection site in mice tumour models.