Analysis of tumor-immune interactions and developing NK cell therapies using CAM model as advanced biomedical technology

Abstract

Immunotherapy and personalized medicine have demonstrated great potential in cancer treatment strategies. Previously, T-cell based immunotherapy has been a frontliner in cancer therapeutics. Although, T-cell based immunotherapy showed promising results but it was only limited to blood cancers and lacked efficiency in targeting and destroying solid tumors. Alternatively, Natural Killer (NK) cell-based immunotherapy has shown promising growth and potential in immunotherapy due to their innate cytotoxic abilities without any prior antigen sensitization. However, previous studies lacked in vivo experiments to support the viability and ability of NK cells to target and kill a solid tumor. To address this shortcoming, this project focused on developing a cost-effective and viable in vivo model using chicken embryo to study the viability and infiltration of NK cells as well as vascularization of tumor spheroid and any possible interactions between them. This project used ex ovo models, taking advantage of its immunodeficiency, high vascularity and experimental accessibility .GFP-labelled Neuroblastoma spheroids were cultured and transplanted onto the chorion allantoic membrane (CAM) of the chicken embryo or into the coelomic cavity at later stages of the experiment followed by injecting Hoechst-labelled NK cells via intracardiac or intravenous injections. Tumor growth and vascularization as well as NK cell distribution and infiltration were assessed using high resolution microscopy and vivo imaging for bioluminescence. Results demonstrated successful engraftment and vascularization of the NBL tumor spheroid on CAM as well as coelomic cavity. NK cells demonstrated higher viability in the presence of IL-15 and persisted for a longer period of time. Although there was no direct targeting or interaction between NK cells and neuroblastoma cells in the CAM model, the tumor engraftment results in the coelomic cavity demonstrated some colocalization between the NK cells and the neuroblastoma cells. This project successfully established a chicken embryo model for tumor vascularization and optimization of NK cell viability. Although some degree of colocalization between NK cells and neuroblastoma cells was observed, further refinement is needed to study tumor disintegration—potentially through methods such as live bioluminescence imaging.