Ex Vivo Generation of Functional Immune Cells by Mitochondria-Targeted Photosensitization of Cancer Cells
Stimulating the immune system for potent immune therapy against cancer is potentially a revolutionary method to eradicate cancer. Tumors stimulated with photosensitizers (PSs) not only kill cancer cells but also help to boost the immune system. We recently reported that tumor-associated antigens (TAAs) generated by delivery of a mitochondria-acting PS zinc phthalocyanine (ZnPc) to MCF-7 breast cancer cells followed by laser irradiation can lead to ex vivo stimulation of mouse bone marrow-derived dendritic cells (BMDCs). The antigens generated from the breast cancer cells were also found to cause significant DC maturation and the activated DCs were able to stimulate T cells to cytotoxic CD8+ T cells. In this protocol, we describe methods to engineer a mitochondria-targeted biodegradable nanoparticle (NP) formulation, T-ZnPc-NPs for delivery of ZnPc to the mitochondria of MCF-7 cells, subsequent photodynamic therapy (PDT) using a long wavelength laser irradiation to produce TAAs, DC stimulation by the TAAs to secrete interferon-gamma (IFN-γ), and matured DC-driven T-cell activation.
Key wordsPhotodynamic therapy Tumor antigen Mitochondria Biodegradable nanoparticle
This work was supported by a start-up grant from the National Institutes of Health (P30 GM 092378) to UGA and by the Office of the Vice President for Research, UGA, to S.D., and a grant from the National Institutes of Health (NIH AI056484) to D.H.
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