Phenotypic and Functional Characterization of Surgery Induced Myeloid Derived Suppressor Cells

Abstract

Removing the bulk of tumor burden with surgery is critical for the recovery of patients with solid malignancies. Surgery, however, induces many physiological changes which impair both NK cell cytotoxicity and cytokine secretion giving circulating tumor cells an opportunity to escape and form distant metastases. The rise of MDSCs in the postoperative landscape has been identified as a major contributor of postoperative NK cell dysfunction. Lack of characterization of both SxMDSC phenotype and suppressive mechanisms are a major challenge in targeting these cells to improve long-term outcomes for patients. This work gives a previously unseen detailed phenotypic description of SxMDSCs, showing a phenotypic switch toward an “M2 like” phenotype after tumor resection. Furthermore, preliminary data from this study identifies a contact-dependent mechanism for SxMDSC suppression of NK cell cytotoxicity and indicates they are likely not a major contributor of suppression NK cell cytokine or cytotoxic granule secretion.