In vivo multiphoton imaging of immune cell dynamics

Abstract

Multiphoton imaging has been utilized to analyze in vivo immune cell dynamics over the last 15 years. Particularly, it has deepened the understanding of how immune responses are organized by immune cell migration and interactions. In this review, we first describe the following technical advances in recent imaging studies that contributed to the new findings on the regulation of immune responses and inflammation. Improved multicolor imaging of immune cell behavior has revealed that their interactions are spatiotemporally coordinated to achieve efficient and long-term immunity. The use of photoactivatable and photoconvertible fluorescent proteins has increased duration and volume of cell tracking, even enabling the analysis of inter-organ migration of immune cells. In addition, visualization of immune cell activation using biosensors for intracellular calcium concentration and signaling molecule activities has started to give further mechanistic insights. Then, we also introduce recent imaging analyses of interactions between immune cells and non-immune cells including endothelial, fibroblastic, epithelial, and nerve cells. It is argued that future imaging studies that apply updated technical advances to analyze interactions between immune cells and non-immune cells will be important for thorough physiological understanding of the immune system.Electronic supplementary materialThe online version of this article (doi:10.1007/s00424-016-1882-x) contains supplementary material, which is available to authorized users.

A bilateral tumor model identifies transcriptional programs associated with patient response to immune checkpoint blockade

“…A major limitation to interrogating such mechanisms in mice has been the inability to couple comprehensive analyses of tumors early during treatment (e.g., when the tumors are still comparable in size between groups) with the ultimate disease outcome later following treatment. While some methods like intravital microscopy (IVM) have been useful for tracking longitudinal antitumor responses in some settings, IVM has a number of limitations that preclude its ability to be widely used for biomarker studies (42,52). Here we utilized a model of resection and response evaluation to investigate the responsiveness of breast tumors to anti-PD-1 blockade using a bilateral tumor approach in mice.…”

ERK Activity Imaging During Migration of Living Cells In Vitro and In Vivo

“…The immune system consists of a variety of cell types. By using cell-specific fluorescent labelling with antibodies conjugated with chemical dyes or transgenic techniques, individual cell dynamics have been visualized in the mouse body with multiphoton excitation microscopes [49]. In FRET-TG mice, neutrophils could be easily distinguished by the segmented nuclei from lymphocytes or macrophages [44].…”

Visualizing Oncolytic Virus-Host Interactions in Live Mice Using Intravital Microscopy

“… 19 , 20 IVM studies have revealed critical insights into the pathogenesis of HIV, 21 influenza, 22 and West Nile, 23 among other viruses, 24 , 25 and the host’s immune response to virus infections. 26 Being increasingly accessible to modern day biomedical laboratories, IVM represents a powerful tool for understanding how viruses naturally infect host cells and are cleared by, or evade, the host’s immune system.…”