Adeno-associated virus serotype rh10 is a useful gene transfer vector for sensory nerves that innervate bone in immunodeficient mice

Sun H Park,Shunsuke Tsuzuki,Christopher M Peters,Aaron G Sunil,Matthew R Eber,D Brooke Widner,Renee A Parker,Yusuke Shiozawa,Mary E Booker

doi:10.1038/s41598-017-17393-z

Sun H Park, Shunsuke Tsuzuki + Show 7 more

Open Access

https://doi.org/10.1038/s41598-017-17393-z

Copy DOI

Abstract

Adeno-associated virus (AAV) is frequently used to manipulate gene expression in the sensory nervous system for the study of pain mechanisms. Although some serotypes of AAV are known to have nerve tropism, whether AAV can distribute to sensory nerves that innervate the bone or skeletal tissue has not been shown. This information is crucial, since bone pain, including cancer-induced bone pain, is an area of high importance in pain biology. In this study, we found that AAVrh10 transduces neurons in the spinal cord and dorsal root ganglia of immunodeficient mice with higher efficacy than AAV2, 5, 6, 8, and 9 when injected intrathecally. Additionally, AAVrh10 has tropism towards sensory neurons in skeletal tissue, such as bone marrow and periosteum, while it occasionally reaches the sensory nerve fibers in the mouse footpad. Moreover, AAVrh10 has higher tropic affinity to large myelinated and small peptidergic sensory neurons that innervate bone, compared to small non-peptidergic sensory neurons that rarely innervate bone. Taken together, these results suggest that AAVrh10 is a useful gene delivery vector to target the sensory nerves innervating bone. This finding may lead to a greater understanding of the molecular mechanisms of chronic bone pain and cancer-induced bone pain.

Highlights

The peripheral ends of sensory nerves express various ion channels and receptors[1]
To determine which associated virus (AAV) serotype has superior gene transduction efficiency to sensory nerves innervating bones, we chose six different serotypes (AAV2, 5, 6, 8, 9, and rh10) which exhibit some degree of nerve tropism in vivo[24,25,26,27]
Higher levels of transduction were observed in the dorsal horn of the spinal cord obtained from mice inoculated with AAV9 and rh[10], whereas minimal or no virus transduction was detected in mice inoculated with AAV2, 5, 6, or 8 (Fig. 1A)

Summary

Introduction

The peripheral ends of sensory nerves express various ion channels and receptors[1]. Despite extensive research characterizing the function of these proteins in nociceptive and sensory processing, there is still a lot that is unclear regarding specialized roles of unique ion channels and receptors in different types of tissue. To dissect the role of these proteins in pain signaling it is useful to modulate the level of candidate genes expressed in sensory neurons. The extent to which the interaction between bone metastatic cancer cells and nociceptive neurons influences CIBP or disease progression is still unknown. To better define the molecular mechanisms of CIBP development, there is a great need for methods that allow gene delivery to the sensory nerves that innervate bone. We performed intrathecal injections of several serotypes of AAV and found that AAVrh[10] has tropism for sensory nerves that innervate the bones of immunodeficient mice. Further studies are clearly warranted, the use of AAVrh[10] may open new avenues in the understanding of the molecular mechanisms of CIBP

Methods

Results

Conclusion