Virginia Research Day 2025

Medical Student Research Biomedical

18 Myeloid-Derived Suppressor Cells Express Diverse Biomarkers Across Tumor Type and are Potential Targets for Cancer-Specific and Personalized Immunotherapies

Foyinsola Olaloye, OMS II 1 ; Ashley Abramson, OMS II 1 ; Mehar Nasir, OMS II 1 ; Andreas Lundqvist, PhD 3 ; Shannon Murray, PhD 1,2 Corresponding author: folaloye@vcom.edu

1 Edward Via College of Osteopathic Medicine 2 Virginia-Maryland College of Veterinary Science, Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University 3 Karolinska Institute, Stockholm, Sweden

Cancers evade the immune system by inducing immunosuppressive tumor microenvironments (TMEs). Tumor cells release cytokines and growth factors that induce myeloid cell precursors to differentiate into an immunosuppressive cell population: myeloid-derived suppressor cells (MDSCs). In cancer patients, MDSCs are found in TMEs and in the blood, where their higher levels correlate with poor prognosis, increased disease progression, and reduced long-term survival. MDSCs are categorized into two major types: monocytic (M-MDSC) and granulocytic (G-MDSC), based on

their molecular marker surface expression. In their normal physiologic role, MDSCs localize to the placenta, wounds, and other sites associated with immunosuppression and 'immune privilege’, where they potently suppress T and natural killer cells. However, MDSC also accumulate with cancer and other pathogenic chronic inflammatory conditions such as sepsis and persistent viral infections. We used a ‘tumor education’ model, an ex vivo tumor-CD14+ monocyte co-culture to mirror MDSC generation during cancer progression. Our model recapitulated aspects of the distinct MDSC populations

preferentially expanded in different cancer types. We demonstrate that melanoma induces more M-MDSCs, whereas renal cell carcinoma (RCC) induces fewer M-MSDC, consistent with the MDSC expanded in these cancer types in patients. We expanded our model using different tumors including lung, bladder, and glioblastoma, and different donors, and we plan to develop this platform as a clinically relevant screening assay for a cancer patient’s immune cell conversion into MDSC upon exposure to tumor and to identify patient-and cancer-specific anti-MDSC therapies.

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2025 Research Recognition Day