Multiple Myeloma Bone Marrow Mesenchymal Stromal Cells Inhibit CD8+ T Cell Function in a Process that May Implicate Fibroblast Activation Protein α

Abstract

Background: Multiple myeloma (MM) is a malignant plasma cell proliferative disorder with limited immunotherapy treatment because of T cell dysfunction. Objective: To investigate the immunomodulatory function of bone marrow mesenchymal stromal cells (MM-BMSCs) on CD8+ T cells. Methods: Proliferation and cytotoxicity were detected by cell counting kit-8 assay. Cell cycle was detected by flow cytometry, and p16 expression was detected by PCR. The expression of fibroblast activation protein α (FAPα) was evaluated by immunohistochemistry. Results: Co-culture of CD8+ T cells with MM-BMSCs decreased the cell survival rate and increased the killing rate (p=0.03, p=0.001, respectively), the percentage of cells in G0/G1 phase and p16 expression (pConclusion: Therefore, MM-BMSCs inhibit the proliferation and cytotoxicity of CD8+ T cells, significantly block the cell cycle and increase p16 expression in co-cultured CD8+ T cells in a cell-cell contact-dependent manner.

Keywords

• bone marrow mesenchymal stromal cells
• cd8+ t cell anergy
• fibroblast activation protein a
• multiple myeloma