Efficacy of Coxsackievirus A5 Vaccine Candidates in an Actively Immunized Mouse Model.

Coxsackievirus A5 (CV-A5) has recently emerged as a main hand, foot, and mouth disease (HFMD) pathogen. Following a large-scale vaccination campaign against enterovirus 71 (EV-71) in China, the number of HFMD-associated cases with EV-71 was reduced, especially severe and fatal cases. However, the total number of HFMD cases remains high, as HFMD is also caused by other enterovirus serotypes. A multivalent HFMD vaccine containing 4 or 6 antigens of enterovirus serotypes is urgently needed. A formaldehyde-inactivated CV-A5 vaccine derived from Vero cells was used to inoculate newborn Kunming mice on days 3 and 10. The mice were challenged on day 14 with a mouse-adapted CV-A5 strain at a dose that was lethal for 14-day-old suckling mice. Within 14 days postchallenge, groups of mice immunized with three formulations, empty particles (EPs), full particles (FPs), and a mixture of the EP and FP vaccine candidates, all survived, while 100% of the mock-immunized mice died. Neutralizing antibodies (NtAbs) were detected in the sera of immunized mice, and the NtAb levels were correlated with the survival rate of the challenged mice. The virus loads in organs were reduced, and pathological changes and viral protein expression were weak or not observed in the immunized mice compared with those in alum-inoculated control mice. Another interesting finding was the identification of CV-A5 dense particles (DPs), facilitating morphogenesis study. These results demonstrated that the Vero cell-adapted CV-A5 strain is a promising vaccine candidate and could be used as a multivalent HFMD vaccine component in the future.IMPORTANCE The vaccine candidate strain CV-A5 was produced with a high infectivity titer and a high viral particle yield. Three particle forms, empty particles (EPs), full particles (FPs), and dense particles (DPs), were obtained and characterized after purification. The immunogenicities of EP, FP, and the EP and FP mixture were evaluated in mice. Mouse-adapted CV-A5 was generated as a challenge strain to infect 14-day-old mice. An active immunization challenge mouse model was established to evaluate the efficacy of the inactivated vaccine candidate. This animal model mimics vaccination, similar to immune responses of the vaccinated. The animal model also tests protective efficacy in response to the vaccine against the disease. This work is important for the preparation of multivalent vaccines against HFMD caused by different emerging strains.

Altered expression of circular RNA in patients with cervical artery dissection.

Cervical artery dissection (CeAD), a special cerebrovascular disease and the main cause of stroke in young people, can present with ischemic stroke, headache, subarachnoid hemorrhage, and other symptoms, increasing the possibility of misdiagnosis. As a special class of non-coding RNAs, circRNAs are commonly found in organisms and can play regulatory roles in transcription and post-transcription processes, affecting gene expression.CircRNAs have reported to be associated with neurological diseases; however, their role in CeAD has not been discerned. In this study, we aimed to elucidate the pathophysiological changes in patients with CeAD and identify biomarkers. Peripheral blood mononuclear cells from patients with CeAD and healthy controls were sequenced using high-throughput sequencing. We detected 460 differently expressed circRNAs in patients with CeAD (p < 0.5, fold difference ≥ 2), of which 240 were upregulated and 220 were downregulated. Four circRNAs showed significant differences in expression, which were validated using qRT-PCR. These results suggested that three circRNAs were consistent with high-throughput sequencing results. Bioinformatics analysis demonstrated that these differentially expressed circRNAs were involved in protein metabolism, regulation, synapses, and other pathophysiological processes during CeAD-induced stroke. Additionally, various pathways related to inflammation were closely associated with circRNAs. Based on our results, we suggest that the aberrant expression of circRNAs in CeAD may serve as a biomarker for its diagnosis and as a potential therapeutic target.

Emergence of a novel recombinant of CV-A5 in HFMD epidemics in Xiangyang, China.

BACKGROUND: Hand, foot and mouth disease (HFMD) is caused by a variety of enterovirus serotypes and the etiological spectrum worldwide has changed since a large scale of outbreaks occurred in 1997. METHODS: A large number of clinical specimens of HFMD patients were collected in Xiangyang and genotyping was performed by qRT-PCR, conventional PCR amplification and sequencing. Among the 146 CV-A5 detected cases, the complete genome sequences of representative strains were determined for genotyping and for recombination analysis. RESULTS: It was found that CV-A5 was one of the six major serotypes that caused the epidemic from October 2016 to December 2017. Phylogenetic analyses based on the VP1 sequences showed that these CV-A5 belonged to the genotype D which dominantly circulated in China. Recombination occurred between the CV-A5 and CV-A2 strains with a breakpoint in the 2A region at the nucleotide 3791. CONCLUSIONS: The result may explain the emergence of CV-A5 as one of the major pathogens of HFMD. A multivalent vaccine against HFMD is urgently needed to control the disease and to prevent emerging and spreading of new recombinants.

Epidemical and etiological study on hand, foot and mouth disease following EV-A71 vaccination in Xiangyang, China.

Coxsackievirus A6 (CV-A6) and Coxsackievirus A10 (CV-A10) have been emerging as the prevailing serotypes and overtaking Enterovirus A71 (EV-A71) and Coxsackievirus A16 (CV-A16) in most areas as main pathogens of hand, foot and mouth disease (HFMD) in China since 2013. To investigate whole etiological spectrum following EV-A71 vaccination of approximate 40,000 infants and young children in Xiangyang, enteroviruses were serotyped in 4415 HFMD cases from October 2016 to December 2017 using Real Time and conventional PCR and cell cultures. Of the typeable 3201 specimen, CV-A6 was the predominant serotype followed by CV-A16, CV-A10, CV-A5, CV-A2 and EV-A71 with proportions of 59.54%, 15.31%, 11.56%, 4.56%, 3.78% and 3.03%, respectively. Other 12 minor serotypes were also detected. The results demonstrated that six major serotypes of enteroviruses were co-circulating, including newly emerged CV-A2 and CV-A5. A dramatic decrease of EV-A71 cases was observed, whereas the total cases remained high. Multivalent vaccines against major serotypes are urgently needed for control of HFMD.