Abstract
Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of myeloid progenitor and precursor cells at different stages of differentiation, which play an important role in tumor immunosuppression. Glioma is the most common and deadliest primary malignant tumor of the brain, and ample evidence supports key contributions of MDSCs to the immunosuppressive tumor microenvironment, which is a key factor stimulating glioma progression. In this review, we summarize the source and characterization of MDSCs, discuss their immunosuppressive functions, and current approaches that target MDSCs for tumor control. Overall, the review provides insights into the roles of MDSC immunosuppression in the glioma microenvironment and suggests that MDSC control is a powerful cellular therapeutic target for currently incurable glioma tumors.
Highlights
Glioma is the most common primary malignant tumor of the brain, and is characterized by high proliferation rates, and migration and invasion abilities
Many studies have demonstrated that cytokines, chemokines, and regulatory immune-suppressive cells [6, 7], such as TGFβ, IL-10, prostaglandin E2, NKT cells, T/B regulatory cells (T/Breg), tumor-associated macrophages/microglia (TAMs), and myeloid-derived suppressor cells (MDSCs) [8], create a specific immunosuppressive tumor microenvironment (TME), which is important for anti-tumor responses and glioma progression
Sinha et al proved that the COX-2 inhibitor, SC58236, delays primary tumor growth and reduces Myeloid-derived suppressor cells (MDSCs) accumulation in spontaneously metastatic BALB/cderived 4T1 mammary carcinoma mouse [121].The chemokine receptor CXCR2 is a receptor of CXC chemokine ligand 2 (CXCL2) which was highly expressed in PMN-MDSC, andplay an important role in MDSCs recruitment [122]
Summary
Glioma is the most common primary malignant tumor of the brain, and is characterized by high proliferation rates, and migration and invasion abilities. Comprehensive treatment includes surgical resection combined with radiotherapy and chemotherapy; such approaches are generally ineffective. The median survival time of patients with the most malignant glioma is approximately 1–2 years despite aggressive therapy, including surgery, radiotherapy and chemotherapy [1]. Development of more effective treatments is urgently required. Immunotherapeutic approaches have been developed for cancer therapy, with exciting progress for some cancers; there are specific challenges for glioma immunotherapy [2]. Many factors may contribute to these difficulties, including the blood-brain barrier (BBB), antigenic and genetic heterogeneity, and the tumor microenvironment (TME)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
