Basic Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 21, 2016; 22(31): 7135-7145
Published online Aug 21, 2016. doi: 10.3748/wjg.v22.i31.7135
Development of a human rotavirus induced diarrhea model in Chinese mini-pigs
Jin-Tao Li, Jing Wei, Hong-Xia Guo, Jiang-Bo Han, Nan Ye, Hai-Yang He, Tian-Tian Yu, Yu-Zhang Wu
Jin-Tao Li, Hong-Xia Guo, Jiang-Bo Han, Nan Ye, Tian-Tian Yu, Institute of Tropical Medicine, Third Military Medical University, Chongqing 400038, China
Jing Wei, Hai-Yang He, Yu-Zhang Wu, Institute of Immunology, PLA, Third Military Medical University, Chongqing 400038, China
Jing Wei, School of Life Science, Southwest University, Chongqing 400715, China
Author contributions: Li JT and Wei J contributed equally to this study and they designed the research and wrote the manuscript; Guo HX, Han JB, Ye N and Yu TT performed the research; He HY contributed new reagents and analytic tools; He HY analyzed the data; Wu YZ contributed the final approval of the article.
Supported by National Natural Science Foundation of China, No. 30400402; and No. 30571708.
Institutional review board statement: This study was reviewed and approved by the Third Military Medical University Institutional Review Board.
Institutional animal care and use committee statement: All procedures involving the care and use of animals were approved by The Institutional Animal Care and Use Committee of the Third Military Medical University.
Conflict-of-interest statement: All authors declare that they have no competing interests about the manuscript.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Jin-Tao Li, PhD, Professor, Institute of Tropical Medicine, Third Military Medical University, Gaotanyan Street 30, Chongqing 400038, China.
Telephone: +86-23-68752329 Fax: +86-23-68752329
Received: March 16, 2016
Peer-review started: March 18, 2016
First decision: May 12, 2016
Revised: May 26, 2016
Accepted: June 13, 2016
Article in press: June 13, 2016
Published online: August 21, 2016

AIM: To establish a new animal model for the research of human rotavirus (HRV) infection, its pathogenesis and immunity and evaluation of potential vaccines.

METHODS: 5-d, 30-d and 60-d-old Chinese mini-pigs, Guizhou and Bamma, were inoculated with a single oral dose of attenuated strain Wa, G1, G3 of HRV, and PBS (control), respectively, and fecal samples of pigs from 0 to 7 d post infection (DPI) were collected individually. Enzyme linked immunosorbent assay was used to detect HRV antigen in feces. The HRV was tested by real-time PCR (RT-PCR). The sections of the intestinal tissue were stained with hematoxylin and eosin to observe the morphologic variation by microscopy. Immunofluorescence was used to determine the HRV in intestinal tissue. HRV particles in cells of the ileum were observed by electron micrography.

RESULTS: When inoculated with HRV, mini-pigs younger than 30 d developed diarrhea in an age-dependent manner and shed HRV antigen of the same inoculum, as demonstrated by RT-PCR. Histopathological changes were observed in HRV inoculated mini-pigs including small intestinal cell tumefaction and necrosis. HRV that was distributed in the small intestine was restricted to the top part of the villi on the internal wall of the ileum, which was observed by immunofluorescence and transmission electron microscopy. Virus particles were observed in Golgi like follicles in HRV-infected neonatal mini-pigs. Guizhou mini-pigs were more sensitive to HRV than Bamma with respect to RV antigen shedding and clinical diarrhea.

CONCLUSION: These results indicate that we have established a mini-pig model of HRV induced diarrhea. Our findings are useful for the understanding of the pathogenic mechanisms of HRV infection.

Keywords: Human rotavirus, Animal model, Chinese mini-pigs, Diarrhea, Intestine

Core tip: Rotavirus (RV) is the leading cause of serious dehydrating diarrhea in infants and young children worldwide. Animal models for RV infection research have provided key insights into the RV infection, its pathogenesis and immunity, and have offered opportunities for design and evaluation of potential vaccines. Our study indicated that human RV (HRV) could effectively replicate in the intestinal villi of the ileum of Chinese mini-pigs and lead to histopathological alterations and diarrhea. This research offers a new animal model for studying the pathological changes and immunogenicity of HRV infection and a useful tool in the design and evaluation of RV vaccines.