1
|
Liu H, Zhang M, Feng C, Cong S, Xu D, Sun H, Yang Z, Ma S. Characterization of Coxsackievirus A6 Strains Isolated From Children With Hand, Foot, and Mouth Disease. Front Cell Infect Microbiol 2021; 11:700191. [PMID: 34490141 PMCID: PMC8418080 DOI: 10.3389/fcimb.2021.700191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 07/26/2021] [Indexed: 11/30/2022] Open
Abstract
Coxsackievirus A6 (CVA6) is a key pathogen causing hand, foot and mouth disease (HFMD). However, there are currently no specific antiviral drugs or vaccines for treating infections caused by CVA6. In this study, human rhabdomyosarcoma (RD), African green monkey kidney (Vero), and human embryonic lung diploid fibroblast (KMB17) cells were used to isolate CVA6 from 327 anal swab and fecal samples obtained during HFMD monitoring between 2009 and 2017. The VP1 genes of the isolates were sequenced and genotyped, and the biological characteristics of the representative CVA6 strains were analyzed. A total of 37 CVA6 strains of the D3 gene subtypes were isolated from RD cells, all of which belonged to the epidemic strains in mainland China. Using the adaptive culture method, 10 KMB17 cell-adapted strains were obtained; however, no Vero cell-adapted strains were acquired. Among the KMB17 cell-adapted strains, only KYN-A1205 caused disease or partial death in suckling mice, and its virulence was stronger than its RD cell-adapted strain. The pathogenic KYN-A1205 strain caused strong tropism to the muscle tissue and led to pathological changes, including muscle necrosis and nuclear fragmentation in the forelimb and hindlimb. Sequence analysis demonstrated that the KYN-A1205 strain exhibited multiple amino acid mutations after KMB17 cell adaptation. Moreover, it showed strong pathogenicity, good immunogenicity and genetic stability, and could be used as an experimental CVA6 vaccine candidate.
Collapse
Affiliation(s)
- Hongbo Liu
- Institute of Medical Biology, Chinese Academy of Medical Sciences, and Peking Union Medical College, Kunming, China.,Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Disease, Kunming, China.,Safety Evaluation Center, Sichuan Institute for Drug Control (Sichuan Testing Center of Medical Devices), Chengdu, China
| | - Ming Zhang
- Institute of Medical Biology, Chinese Academy of Medical Sciences, and Peking Union Medical College, Kunming, China.,Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Disease, Kunming, China
| | - Changzeng Feng
- Institute of Medical Biology, Chinese Academy of Medical Sciences, and Peking Union Medical College, Kunming, China.,Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Disease, Kunming, China
| | - Shanri Cong
- Institute of Medical Biology, Chinese Academy of Medical Sciences, and Peking Union Medical College, Kunming, China.,Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Disease, Kunming, China
| | - Danhan Xu
- Institute of Medical Biology, Chinese Academy of Medical Sciences, and Peking Union Medical College, Kunming, China.,Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Disease, Kunming, China
| | - Hao Sun
- Institute of Medical Biology, Chinese Academy of Medical Sciences, and Peking Union Medical College, Kunming, China.,Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Disease, Kunming, China
| | - Zhaoqing Yang
- Institute of Medical Biology, Chinese Academy of Medical Sciences, and Peking Union Medical College, Kunming, China.,Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Disease, Kunming, China
| | - Shaohui Ma
- Institute of Medical Biology, Chinese Academy of Medical Sciences, and Peking Union Medical College, Kunming, China.,Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Disease, Kunming, China
| |
Collapse
|