In vivo imaging system for cellular level visualization of immune responses in various animal models

Abstract

Immune cells have a variety of functions to defend against pathogens under certain circumstances. It is not until recently, However, that these miscellaneous responses can be observed in vivo. Herein, we optimized some solutions of researchers keeping track of the changes of the immune response by utilizing the IVM-C intravital imaging system and in vivo fluorescence labeling for target cells. It is possible to successfully acquire a crystal-clear cellular level images of immune cells in the different animal model including RNA adjuvant-injected mouse and sepsis-induced one by using intravital microscope, respectively. In case of the RNA adjuvant injection, it is obvious that retention of the antigen presenting cells in draining lymph node is on the rise to promote T/B cell activation. A dramatic increase in the number of the infiltrated dendritic cells into the organ was observed at the same time. Moreover, Pathogenesis of sepsis by monitoring of pulmonary capillary circulation was investigated. In order to visualize pulmonary microcirculation, we’ve established a pulmonary imaging window which makes it feasible to image the real-time dynamics of rapidly circulating neutrophils in live mouse. We found out that many clusters of neutrophils aggregates in the pulmonary vasculature or, even in the arteriole of the sepsis-induced mouse, thereby disturbing the microcirculation of that region and generating dead space in the pulmonary structure. Taking everything into account, we make certain it is appropriate to utilize the intravital imaging method for cellular level visualization of the immune system under various pathological conditions. we believe that it could be an invaluable tool for a comprehensive understanding of immunology.