Flow cytometric detection of CD11b+ Gr-1+ cells in nontumor-bearing mice: A propolis-elicited model.

Myeloid-derived suppressor cells (MDSCs) are a heterogenous myeloid lineage population whose conventional surface phenotype is CD11b⁺ Gr-1⁺. Due to their rarity and fragility, analyses using primary isolated MDSCs are extremely difficult. However, counting CD11b⁺ Gr-1⁺ cells in associated tissues such as tumors and inflammatory lesions provides critical information regarding MDSC involvement in immune disorders in the tissues. Specific MDSC markers have not been identified, limiting our ability to apply histochemical approaches during MDSCs research. However, profiling surface antigens using multi-colorimetric flow cytometry enables us to easily monitor the abundance of MDSCs in vivo. Monitoring of mouse MDSCs and their subpopulations using flow cytometry is well established. In this article, I exemplify a conventional method of monitoring CD11b⁺ Gr-1⁺ cells in mouse adipose tissue after administration of Brazilian propolis ethanol extract, which is a strong inducer of MDSCs.