Application of In Vivo Imaging Techniques for Monitoring Natural Killer Cell Migration and Tumor Infiltration.

Prakash Gangadaran,Byeong-Cheol Ahn,Ramya Lakshmi Rajendran

doi:10.3390/cancers12051318

Prakash Gangadaran, Byeong-Cheol Ahn + Show 1 more

Open Access

https://doi.org/10.3390/cancers12051318

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Abstract

In recent years, the use of natural killer (NK) cell-based immunotherapy has shown promise against various cancer types. To some extent therapeutic potential of NK cell-based immunotherapy depends on migration of NK cells towards tumors in animal models or human subjects and subsequent infiltration. Constant improvement in the pharmacological and therapeutic properties of NK cells is driving the performance and use of NK cell-based immunotherapies. In this review, we summarize the molecular imaging techniques used in monitoring the migration and infiltration of NK cells in vivo at preclinical and clinical levels. A review of pros and cons of each molecular imaging modality is done. Finally, we provide our perception of the usefulness of molecular imaging approaches for in vivo monitoring of NK cells in preclinical and clinical scenarios.

Highlights

Natural killer (NK) cells, a type of lymphocyte, were first reported almost four decades ago.They are granular in nature and are involved in immune-surveillance [1]
The tumor microenvironment poses a major challenge to clinical applications of the natural killer (NK) cell due to immune suppressive signals that disturb both tumoral infiltration of NK cells and their activation at the tumor site [6]
Fluorescence imaging revealed the migration of the NK cells to tumor-associated epithelial cell adhesion molecule (EpCAM) expressing human prostate cancer cells in a mouse model 90 min-post intravenous injection of the NK cells

Summary

Introduction

Natural killer (NK) cells, a type of lymphocyte, were first reported almost four decades ago They are granular in nature and are involved in immune-surveillance [1]. NK cells are a promising cell type for adoptive cell therapy for several reasons They do not require priming or prior sensitization to interact with and kill tumor cells [3,4]. Limited efficiency of NK cells depends on the number of malignant cells that are killed by one NK cell and migration speed of NK cells These limitations hamper the efficacy of the immune system to the tumor. Non-invasive in vivo real-time imaging of NK cells in animal tumor models and human subjects become important in this context to determine the NK treatment success and efficacy. We review the development of the technologies and designs that has led to the currently available sophisticated methods with specific in vivo examples

Non-Invasive In Vivo Imaging Modalities

An overview of steps in tracking

Challenges in the tomography

Future Prospects of In Vivo NK Cell Imaging

Findings

Conclusions