Myeloid-derived suppressor cells: Identification and function

Area of Science:

• Immunology
• Cell Biology

Background:

• Myeloid-derived suppressor cells (MDSCs) are key regulators of immune responses and inflammation.
• MDSCs exhibit dual roles, impacting diseases such as cancer, infections, sepsis, and trauma.
• They suppress immune cell activity via immunosuppressive factors and are classified into monocytic (M) and polymorphonuclear (PMN) lineages.

Purpose of the Study:

• To summarize protocols for identifying and functionally characterizing MDSCs.
• To focus on the identification and characterization of polymorphonuclear (PMN)-MDSCs.
• To emphasize the necessity of confirming inhibitory capacity for MDSC definition.

Main Methods:

• Review of established markers for MDSC identification.
• Description of functional assays to confirm MDSC inhibitory capacity.
• Detailed protocol for characterizing PMN-MDSCs in peripheral blood and tumor microenvironments.

Main Results:

• PMN-MDSCs are the predominant subtype found in peripheral blood and tumor tissues.
• MDSCs directly inhibit immune cell function, contributing to tumor progression.
• Standardized protocols are essential for accurate MDSC assessment.

Conclusions:

• Accurate identification of MDSCs, particularly PMN-MDSCs, is critical for understanding their role in disease.
• Functional assays confirming immunosuppressive capacity are indispensable for MDSC definition.
• Established protocols facilitate research into MDSC-targeted therapies.