ABSTRACT
Objective@#To construct the recombinant Crimean-Congo hemorrhagic fever virus (CCHFV) which can express the secreted nanoluciferase (NanoLuc) and investigate its potential application for rapid antiviral compounds screening.@*Methods@#The ORF of NanoLuc and the mucin encoded by the M segment of CCHFV were merged, and the recombinant CCHFV (rCCHFV) was rescued through reverse genetic system. Then rCCHFV was used to evaluate the antiviral effect for ribavirin and Furin inhibitor in vitro.@*Results@#The rCCHFV_mucin_NLuc with NanoLuc reporter was obtained, and the relative light unit (RLU) which can reflect NanoLuc activity was positively correlated with median tissue culture infective dose (TCID50) in the infected cell supernatant (cor=0.998, P=0.001). When the concentration for the compounds was 10 μmol/L, there was no significant difference for the NanoLuc activity in the infected cell supernatant between Furin inhibitor and ribavirin (P > 0.1) from day 1 to 3 after treatment. But at day 4, the NanoLuc activity in Fruin inhibitor treated group was significantly higher than that of ribavirin treated group (P=0.001), and no significant difference was found between the Furin inhibitor and untreated group (P > 0.1).@*Conclusions@#The rCCHFV with NanoLuc reporter was recovered successfully and it could be used for the primary rapid screening of antiviral compounds in future.
ABSTRACT
Severe Fever with Thrombocytopenia Syndrome (SFTS) and Crimean-Congo Haemorrhagic Fever (CCHF) are tick-borne diseases belonging to the family Bunyaviridae. Since SFTS was first reported in China in 2009, the virus was isolated and confirmed in 2011, with additional reports of SFTSV expanding its geographic range from China to South Korea and Japan. CCHFV has the widest geographic distribution of any tick-borne virus, encompassing around 30 countries from eastern China through Asia, the Middle East, and southeastern Europe to Africa. During the past decade, CCHFV has emerged in new areas of Europe, Africa, the Middle East, and Asia and has increased in endemic areas. Migratory birds are considered to play a role in dispersing CCHFV vectors, and the virus. This review summarises SFTSV and CCHFV, highlighting the role of migratory birds in the transmission of tick-borne disease.
Subject(s)
Humans , Africa , Asia , Birds , Bunyaviridae , China , Europe , Fever , Hemorrhagic Fever Virus, Crimean-Congo , Japan , Middle East , Republic of Korea , Thrombocytopenia , Tick-Borne Diseases , VirusesABSTRACT
Crimean-Congo hemorrhagic fever (CCHF) is a severe illness with high fatality.Cases are reported in several countries in Africa,Europe,the Middle East,and Asia.Phylogenetic analyses based on the virus S (nucleocapsid),M (glycoprotein),and L (polymerase) genome segments sequences indicate distinct geographic lineages exist but their specific genetic characteristics require elucidation.In this work we collected all full length S segment sequences and generated a phylogenetic tree based on the alignment of these 62 samples.We then analyzed the alignment using entries from AAIndex,the Amino Acid Index database,to identify amino acid mutations that performed significant changes in charge,pka,hydropathy and side chain volume.Finally,we mapped these changes back to the tree and alignment to identify correlated mutations or sites that characterized a specific lineage.Based on this analysis we are able to propose a number of sites that appear to be important for virus function and which would be good candidates for experimental mutational analysis studies.
ABSTRACT
Crimean-Congo Haemorrhagic Fever Virus(CCHFV)is a tick-born virus of the Nairovirus genus within the Bunyaviridae family,which is widespread and causes,high fatality. The nucleocapsid of CCHFV is comprised of N proteins that are encoded by the S segment. In this research,the N protein of CCHFV was expressed in insect cells using a recombinant baculovirus. Under an electron microscope,Virus-Like Particles (VLPs)with various size and morphology were observed in cytoplasmic vesicles in the infected cells.Sucrose-gradient purification of the cell lysate indicated that the VLPs were mainly located in the upper fraction after ultracentrifugation,which was confirmed by Western blot analysis and immuno-electron microscopy(IEM).
ABSTRACT
The Crimean-congo hemorrhagic fever virus(CCHFV)is a geographically widespread fatal pathogen.Identification of the epitope regions of the virus is important for the diagnosis and epidemiological studies of CCHFV infections.In this study,expression vectors carrying series truncated fragments of the NP(nueleoeapsid protein)gene from the S fragment of CCHFV strain YL04057 were constructed.The recombinant proteins were expressed in E.coli and purified for detection.The antigenic of the truncated fragments of NP was detected with a polyclonai serum(rabbit)and 2 monoclonal(mAbs)(14B7 and 43E5)against CCHFV by Western-blot analyses.The results showed that the three expressed constructs,which all contained the region 235AA to 305AA could be detected by mAbs polyclonal serum.The results suggest that region 235-305 aa of NP is a highly antigenic region and is highly conserved in the NP protein.