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New Biological Frontiers Illuminated by Molecular Sensors and Actuators
Monday Speaker Abstracts
Genetically Encoded Tools to Manipulate and Observe Cellular Dynamics in Cardiac
Disease Modelling and Drug Screening
Yu-Fen Chang
, Frances Book, Mark J. Davies, Matthew J. Daniels.
University of Oxford, Oxford, United Kingdom.
See abstract: Pos-5 Board 5
Intravital Microscopy of Fluorescent Protein Model Antigen-Elicited Specific Immune
Response
Zhihong Zhang
.
Huazhong University of Science and Technology, Wuhan, China.
Intravital optical imaging provided a useful approach for clarifying how, when, and where the
immune cells involved in tumor immunity. Model antigens have been widely used to simplify
the investigation of complicated anti-tumor immune response. However, the classical model
antigens (e.g., OVA) cannot be directly detected without fluorescent labeling. Thus, it’s
necessary to develop a visualized model antigen system based on fluorescent protein itself for the
intravital imaging of tumor immunity. Fluorescent protein KatushkaS158A displayed perfect
optical characters and was quite suitable for optical imaging in vivo. The data indicated that it
elicited both cellular and humoral immune response in the immunized C57BL/6 mice, resulting
in the attenuation of the tumorigenesis of KatushkaS158A-expressing melanoma cells (K-B16)
in vivo. To visualize the specific anti-tumor immune response in tumor microenvironment,
EGFP-transgenic C57BL/6 mice were immunized twice with IFA-emulsified KatushkaS158A on
Day 14 and Day 7 before the implantation of K-B16 cells into the dorsal skin-fold window
chambers. The intravital imaging data indicated that strong and specific immune response
against K-B16 cells was occurred in the KatushkaS158A-immunized mice at 2 days after the
implantation of K-B16 cells, which swarms of EGFP+ immunocytes rushed toward the tumor
cells with significantly higher motility and retained in the middle of the tumor area with high
density. These responsive immunocytes eliminated K-B16 cells and blocked the growth of
melanoma cells in vivo. Thus, KatushkaS158A protein was not only acted as a fluorescent
marker for tumor imaging, but also used as a model antigen to elicit specific tumor immune
response in C57BL/6 mice.