Preliminary Analysis of Cellular Sociology of Co-Cultured Glioma Initiating Cells and Macrophages in Vitro

Abstract

Objective Real-time monitoring of cytokine secretion at the single immunocyte level, based on the concept of immune cells, sociology has been recently reported. However, the relationships between glioma-initiating cells (GICs) and host immune cells and their mutual interactions in the tumor microenvironment have not been directly observed and remain unclear. Methods The dual fluorescence tracing technique was applied to label the co-cultured GICs and host macrophages (Mø), and the interactions between the two types of cells were observed using a live cell imaging system. Fusion cells in the co-culture system were monocloned and proliferated in vitro and their social interactions were observed and recorded. Results Using real-time dynamic observation of target cells, 6 types of intercellular conjunction microtubes were found to function in the transfer of intercellular information between GICs and Mo; GICs and host Mø can fuse into hybrid cells after several rounds of mutual interactions, and then these fusion cells fused with each other; Fusion cells generated offspring cells through symmetrical and asymmetrical division or underwent apoptosis. A “cell in cell” phenomenon was observed in the fusion cells, which was often followed by cell release, namely entosis. Conclusions Preliminary studies revealed the patterns of cell conjunction via microtubes between GICs and host Mø and the processes of cell fusion, division, and entosis. The results revealed malignant transformation of host Mø, induced by GICs, suggesting complex social relationships among tumor-immune cells in gliomas.