The interaction of tumor cells and myeloid-derived suppressor cells in chronic myelogenous leukemia

Abstract

Myeloid-derived suppressor cells (MDSCs) are considered to be a strong contributor to the immunosuppressive tumor microenvironment. In our study, the counts of MDSCs were correlated with the remission status of CML patients, especially the M-MDSCs. M-MDSCs promoted the proliferation of K562 cells or CD34+ cells from newly diagnosed CML patients, no matter in cells or mice experiments. We also established a TKI discontinuation model using the K562 cell line for examining the effect of microvesicles (MVs) derived from K562 cells before and after TKI discontinuation on MDSCs. We found a mutual promotion of proliferation of tumor cells and MDSCs. Moreover, MVs derived from K562 cells after TKI discontinuation significantly improved the proliferation of MDSCs compared with MVs from before TKI discontinuation. The bidirectional interaction results in a vicious cycle, by providing a protective niche against immune attacks. Therapeutic interventions modulating this interaction might accelerate the success of TFR.

Keywords:

• Chronic myelogenous leukemia (CML)
• myeloid-derived suppressor cells (MDSCs)
• microvesicles (MVs)
• treatment-free remission (TFR)

Disclosure statement

The authors report no conflict of interest.

Consent

Informed consent was obtained from all individual participants included in the study.

Additional information

Funding

This study was funded by the grant from the National Natural Science Foundation of China [Grant no. 81700142].