EXTH-59. IMMORTALIZATION OF MOUSE BONE MARROW-DERIVED MACROPHAGES FOR BRAIN TUMOR THERAPY DEVELOPMENT

Abstract BACKGROUND Macrophages can cross blood-brain-barrier (BBB) and infiltrate brain parenchyma with malignancies such as glioma. Recently, many efforts have been made to develop macrophage-based cancer therapy, including CAR–macrophages. However, lack of proliferation in differentiated macrophages hinders their utility. We sought ameliorate this problem by immortalizing assist potential therapy development. Bone marrow derived (BMDMs) were harvested from C57Bl/6 mice transduced mouse telomerase reverse transcriptase (mTert) gene via retrovirus. Following puromycin selection, morphology, proliferation, lineage marker expression phagocytosis measured microscopy, flow cytometry IncuCyte assays. RESULTS Through overexpression mTert, we successfully immortalized BMDMs, termed iBMDMs. Morphologically, iBMDMs largely maintained features primary BMDMs. The established proliferated for over 20 subcultures without obvious reduction growth. Proliferation (doubling time, dt=52h) was similar IC-21(dt=53h), an macrophage line SV40-T antigen, slower than Raw264.7 (dt=23h), driven murine leukemia virus. Furthermore, grow colony-stimulating factor (M-CSF) (dt=54h). Macrophage markers CD11B F4/80 levels higher BMDMs (CD11B+=62.8±0.53%, F4/80+=54.9±0.38%, CD11B+F4/80+=52.7±0.41%, n=2 all results) (CD11B+=39.1±5.29%, F4/80+=26.4±7.93%, CD11B+F4/80+=24.6±5.95%) IC-21 (CD11B+=10.7±0.37%, F4/80+=19.4±1.88%, CD11B+F4/80+=9.13±0.37%) (CD11B+=34.3±5.32%, F4/80+=14.1±4.40%, CD11B+F4/80+=8.33±4.19%) cells lines. Lastly, evaluated the phagocytic ability through Similar observed a concentration dependent increase red fluorescence, which indicates E. coli bioparticles, M-CSF. CONCLUSIONS bone marrow-derived origin competent immune function mTert transduction. These be used preclinical immunotherapy development glioma treatment. Ongoing work is focused on assessing penetrate BBB tumor model.