Flow cytometry analysis of myeloid derived suppressor cells using 6 color labeling

Myeloid-derived suppressor cells (MDSCs) encompass a diverse population of immature myeloid cells categorized into granulocytic and monocytic groups. These cells exert immune-suppressive functions within the tumor microenvironment, primarily influenced by cytokines and tumor-associated factors. Research has consistently linked elevated MDSC levels to unfavorable cancer prognosis and poor responses to immunotherapies. Here, we detail the materials, equipment, and methods involved in MDSC analysis in human peripheral blood by flow cytometry, emphasizing the importance of selecting appropriate antibody clones and fluorochromes for precise cell population discrimination. The gating strategy is described, with particular attention to the challenges associated with defining conjugated antibody labeling positive and negative populations.