Cross-genotype protection of live-attenuated #vaccine candidate for #SFTS virus in a #ferret model (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Cross-genotype protection of live-attenuated vaccine candidate for severe fever with thrombocytopenia syndrome virus in a ferret model

Kwang-Min Yu, Su-Jin Park, Min-Ah Yu, Young-Il Kim, Younho Choi, Jae U. Jung, Benjamin Brennan, and Young Ki Choi

PNAS first published December 9, 2019 / DOI:

Edited by Peter Palese, Icahn School of Medicine at Mount Sinai, New York, NY, and approved November 5, 2019 (received for review August 23, 2019)



Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging viral pathogen discovered in 2009. The virus is present in countries of East Asia and is transmitted through the bite of an infected Haemaphysalis longicornis tick. SFTSV disease is associated with high morbidity and is often fatal. Despite the incidence of disease, no antiviral therapy or vaccine has been approved for use. Here, we report and assess 2 live attenuated viruses as vaccine candidates in our recently described ferret model of infection. We show that the viruses caused no clinical disease or mortality in healthy animals. Immunized animals mounted a robust humoral immune response to a single dose of virus, and this response protected the animals from a lethal challenge.



Severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) is an emerging tick-borne virus classified within the Banyangvirus genus. SFTS disease has been reported throughout East Asia since 2009 and is characterized by high fever, thrombocytopenia, and leukopenia and has a 12 to 30% case fatality rate. Due to the recent emergence of SFTSV, there has been little time to conduct research into preventative measures aimed at combatting the virus. SFTSV is listed as one of the World Health Organization’s Prioritized Pathogens for research into antiviral therapeutics and vaccine development. Here, we report 2 attenuated recombinant SFTS viruses that induce a humoral immune response in immunized ferrets and confer complete cross-genotype protection to lethal challenge. Animals infected with rHB29NSsP102A or rHB2912aaNSs (both genotype D) had a reduced viral load in both serum and tissues and presented without high fever, thrombocytopenia, or mortality associated with infection. rHB29NSsP102A- or rHB2912aaNSs-immunized animals developed a robust anti-SFTSV immune response against cross-genotype isolates of SFTSV. This immune response was capable of neutralizing live virus in a focus-reduction neutralization test (FRNT) and was 100% protective against a cross-genotype lethal challenge with the CB1/2014 strain of SFTSV (genotype B). Thus, using our midsized, aged ferret infection model, we demonstrate 2 live attenuated vaccine candidates against the emerging pathogen SFTSV.

SFTS – emerging banyangvirus – live attenuated vaccine – ferret model – bunyavirus

Keywords: Bunyavirus; Banyangvirus; SFTS; Vaccines; Animal models.


Fluorescent #CCHF virus illuminates tissue #tropism patterns and identifies early mononuclear phagocytic cell targets in IFNAR-/- mice (PLOS Pathog., abstract)

[Source: PLOS Pathogens, full page: (LINK). Abstract, edited.]


Fluorescent Crimean-Congo hemorrhagic fever virus illuminates tissue tropism patterns and identifies early mononuclear phagocytic cell targets in IFNAR-/- mice

Stephen R. Welch, Jana M. Ritter, Anita K. McElroy, Jessica R. Harmon, JoAnn D. Coleman-McCray, Florine E. M. Scholte, Gary P. Kobinger, Éric Bergeron, Sherif R. Zaki, Stuart T. Nichol, Jessica R. Spengler , Christina F. Spiropoulou


Published: December 2, 2019 / DOI: / This is an uncorrected proof.



Crimean-Congo hemorrhagic fever virus (CCHFV, order Bunyavirales, family Nairoviridae, genus Orthonairovirus) is the tick-borne etiological agent of Crimean-Congo hemorrhagic fever (CCHF) in humans. Animals are generally susceptible to CCHFV infection but refractory to disease. Small animal models are limited to interferon-deficient mice, that develop acute fatal disease following infection. Here, using a ZsGreen1- (ZsG) expressing reporter virus (CCHFV/ZsG), we examine tissue tropism and dissemination of virus in interferon-α/β receptor knock-out (Ifnar-/-) mice. We demonstrate that CCHFV/ZsG retains in vivo pathogenicity comparable to wild-type virus. Interestingly, despite high levels of viral RNA in all organs assessed, 2 distribution patterns of infection were observed by both fluorescence and immunohistochemistry (IHC), corresponding to the permissiveness of organ tissues. To further investigate viral dissemination and to temporally define cellular targets of CCHFV in vivo, mice were serially euthanized at different stages of disease. Flow cytometry was used to characterize CCHFV-associated alterations in hematopoietic cell populations and to classify infected cells in the blood, lymph node, spleen, and liver. ZsG signal indicated that mononuclear phagocytic cells in the lymphatic tissues were early targets of infection; in late-stage infection, overall, the highest levels of signal were detected in the liver, and ZsG was found in both antigen-presenting and lymphocyte cell populations.


Author summary

Human infection by tick-borne Crimean-Congo hemorrhagic fever virus (CCHFV) can result in severe disease with up to 30% case fatality rates. While CCHFV is known to be hepatotropic, the presence and implications of virus in other tissues are less clear. Furthermore, to date, early cellular targets of infection in a CCHFV disease model have not been investigated in detail. Here, using a recombinant reporter CCHFV expressing the fluorescent protein ZsGreen1 (ZsG; CCHFV/ZsG) in interferon-α/β receptor knock-out (Ifnar-/-) mice, which develop acute fatal disease following infection, we investigate both cellular and tissue targets of infection. Importantly, we find that CCHFV/ZsG infection demonstrated comparable pathogenicity to wild-type virus in Ifnar-/- mice. We used in situ visualization of fluorescent signal in tissues to assess viral dissemination throughout the course of infection, and found robust viral signal in reproductive tissues, previously unrecognized as sites of CCHFV infection. We also used flow cytometry to detect intracellular fluorescent signal, and identified initial target cells of CCHFV infection as macrophage and monocyte populations in lymphatic tissues. These findings support a central role of immune cells in early virus dissemination, and a need for further investigations into reproductive tract involvement in human CCHFV infection.


Citation: Welch SR, Ritter JM, McElroy AK, Harmon JR, Coleman-McCray JD, Scholte FEM, et al. (2019) Fluorescent Crimean-Congo hemorrhagic fever virus illuminates tissue tropism patterns and identifies early mononuclear phagocytic cell targets in IFNAR-/- mice. PLoS Pathog 15(12): e1008183.

Editor: Veronika von Messling, Federal Ministry of Education and Research, GERMANY

Received: June 4, 2019; Accepted: November 1, 2019; Published: December 2, 2019

This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Data Availability: All relevant data are within the manuscript and its Supporting Information files.

Funding: This work was partially supported by an appointment to the Research Participation Program at the Centers for Disease Control and Prevention administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and CDC (S.R.W.), by a CDC foundation project funded by NIAID grant R01AI109008 (E.B.), and by CDC Emerging Infectious Disease Research Core Funds. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: CCHF; Viral pathogenesis.


#Đakrông virus, a novel #mobatvirus (#Hantaviridae) harbored by the Stoliczka’s Asian trident #bat (Aselliscus stoliczkanus) in #Vietnam (Sci Rep., abstract)

[Source: Scientific Reports, full page: (LINK). Abstract, edited.]

Article | OPEN | Published: 15 July 2019

Đakrông virus, a novel mobatvirus (Hantaviridae) harbored by the Stoliczka’s Asian trident bat (Aselliscus stoliczkanus) in Vietnam

Satoru Arai, Keita Aoki, Nguyễn Trường Sơn, Vương Tân Tú, Fuka Kikuchi, Gohta Kinoshita, Dai Fukui, Hoàng Trung Thành, Se Hun Gu, Yasuhiro Yoshikawa, Keiko Tanaka-Taya, Shigeru Morikawa, Richard Yanagihara & Kazunori Oishi

Scientific Reports, volume 9, Article number: 10239 (2019)



The recent discovery of genetically distinct shrew- and mole-borne viruses belonging to the newly defined family Hantaviridae (order Bunyavirales) has spurred an extended search for hantaviruses in RNAlater®-preserved lung tissues from 215 bats (order Chiroptera) representing five families (Hipposideridae, Megadermatidae, Pteropodidae, Rhinolophidae and Vespertilionidae), collected in Vietnam during 2012 to 2014. A newly identified hantavirus, designated Đakrông virus (DKGV), was detected in one of two Stoliczka’s Asian trident bats (Aselliscus stoliczkanus), from Đakrông Nature Reserve in Quảng Trị Province. Using maximum-likelihood and Bayesian methods, phylogenetic trees based on the full-length S, M and L segments showed that DKGV occupied a basal position with other mobatviruses, suggesting that primordial hantaviruses may have been hosted by ancestral bats.

Keywords: Mobatvirus; Hantavirus; Bats; Bunyavirus; Dakrong virus; Vietnam.


SNX11 Identified as an Essential #Host Factor for #SFTS Virus #Infection by #CRISPR Knockout Screening (Virol Sin., abstract)

[Source: Virologica Sinica, full page: (LINK). Abstract, edited.]

SNX11 Identified as an Essential Host Factor for SFTS Virus Infection by CRISPR Knockout Screening

Authors: Tiezhu Liu, Jiajia Li, Yang Liu, Yuanyuan Qu, Aqian Li, Chuan Li, Quanfu Zhang,Wei Wu, Jiandong Li, Yan Liu, Dexin Li, Shiwen Wang, Mifang Liang

Research Article / First Online: 18 June 2019



Severe fever with thrombocytopenia syndrome virus (SFTSV) is a highly pathogenic tick-borne bunyavirus that causes lethal infectious disease and severe fever with thrombocytopenia syndrome (SFTS) in humans. The molecular mechanisms and host cellular factors required for SFTSV infection remain uncharacterized. Using a genome-wide CRISPR-based screening strategy, we identified a host cellular protein, sorting nexin 11 (SNX11) which is involved in the intracellular endosomal trafficking pathway, as an essential cell factor for SFTSV infection. An SNX11-KO HeLa cell line was established, and SFTSV replication was significantly reduced. The glycoproteins of SFTSV were detected and remained in later endosomal compartments but were not detectable in the endoplasmic reticulum (ER) or Golgi apparatus. pH values in the endosomal compartments of the SNX11-KO cells increased compared with the pH of normal HeLa cells, and lysosomal-associated membrane protein 1 (LAMP1) expression was significantly elevated in the SNX11-KO cells. Overall, these results indicated that penetration of SFTSV from the endolysosomes into the cytoplasm of host cells was blocked in the cells lacking SNX11. Our study for the first time provides insight into the important role of the SNX11 as an essential host factor in the intracellular trafficking and penetrating process of SFTSV infection via potential regulation of viral protein sorting, membrane fusion, and other endocytic machinery.

Keywords: CRISPR – screen – Severe fever with thrombocytopenia syndrome virus (SFTSV) – Host factor – Sorting nexin 11 (SNX11)

Electronic supplementary material

The online version of this article ( contains supplementary material, which is available to authorized users.




This work was supported by the National Key Project for Infectious Disease from the Ministry of Science and Technology (Grant No. 2018ZX10711-001).

Author Contributions

TL performed the experiments and wrote the paper; Jiajia Li, YL, and YQ performed the experiments; AL, QZ, CL, WW, YL, and Jiandong Li contributed reagents/materials/analysis tools. Jiajia Li, TL, ML, YL, Jiandong Li, and DL analyzed and discussed the data. ML and SW designed the project and edited the manuscript. All authors read and approved the final manuscript.


Compliance with Ethical Standards

Conflict of interest

The authors declare that they have no conflict of interest.

Animal and Human Rights Statement

This article does not contain any studies with human or animal subjects performed by any of the authors.

Keywords: SFTS virus; Bunyavirus; CRISPR; Viral pathogenesis.


Preexisting #chronic #conditions for #fatal #outcome among #SFTS patients: An observational Cohort Study (PLoS Negl Trop Dis., abstract)

[Source: PLoS Neglected Tropical Diseases, full page: (LINK). Abstract, edited.]


Preexisting chronic conditions for fatal outcome among SFTS patients: An observational Cohort Study

Shao-Fei Zhang , Zhen-Dong Yang , Mao-Lin Huang , Zhi-Bo Wang, Yuan-Yuan Hu, Dong Miao, Ke Dai, Juan Du, Ning Cui, Chun Yuan, Hao Li, Xiao-Kun Li, Xiao-Ai Zhang,  [ … ], Wei Liu

Published: May 28, 2019 / DOI: / This is an uncorrected proof.



Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that is caused by a novel bunyavirus SFTSV. Currently our knowledge of the host-related factors that influence the pathogenesis of disease is inadequate to allow prediction of fatal outcome. Here we conducted a prospective study of the largest database on the SFTS patients, to identify the presence of comorbidities in SFTS, and estimate their effect on the fatal outcome. Among 2096 patients eligible for inclusion, we identified nine kinds of comorbidities, from which hyperlipidemia (12.2%; 95% CI: 10.8%–13.6%), hypertension (11.0%; 95% CI: 9.6%–12.3%), chronic viral hepatitis (CVH) (9.3%; 95% CI: 8.1%–10.5%), and diabetes mellitus (DM) (6.8%; 95% CI: 5.7%–7.9%) were prevalent. Higher risk of death was found in patients with DM (adjusted OR = 2.304; 95% CI: 1.520–3.492; P<0.001), CVH (adjusted OR = 1.551; 95% CI: 1.053–2.285; P = 0.026) and chronic obstructive pulmonary diseases (COPD) (adjusted OR = 2.170; 95% CI: 1.215–3.872; P = 0.009) after adjusting for age, sex, delay from disease onset to admission and treatment regimens. When analyzing the comorbidities separately, we found that the high serum glucose could augment diseases severity. Compared to the group with max glucose < 7.0 mmol/L, patients with glucose between 7.0–11.1 mmol/L and glucose ≥11.1 mmol/L conferred higher death risk, with the adjusted OR to be 1.467 (95% CI: 1.081–1.989; P = 0.014) and 3.443 (95% CI: 2.427–4.884; P<0.001). Insulin therapy could effectively reduce the risk of severe outcome in DM patients with the adjusted OR 0.146 (95% CI: 0.058–0.365; P<0.001). For CVH patients, severe damage of liver and prolongation of blood coagulation time, as well as high prevalence of bleeding phenotype were observed. These data supported the provocative hypothesis that treating SFTS related complications can attain potentially beneficial effects on SFTS.


Author summary

SFTS now brings about a substantial global public health concern. Preexisting chronic conditions were thought to increase risk of severe SFTSV infections, however with sparse data mining efforts. In this study, we quantified the frequency of chronic comorbidities in SFTS, estimated their contribution to disease severity, and separately evaluated the effect from diabetes mellitus and chronic viral hepatitis on resulting in fatal outcome.


Citation: Zhang S-F, Yang Z-D, Huang M-L, Wang Z-B, Hu Y-Y, Miao D, et al. (2019) Preexisting chronic conditions for fatal outcome among SFTS patients: An observational Cohort Study. PLoS Negl Trop Dis 13(5): e0007434.

Editor: Patricia V. Aguilar, University of Texas Medical Branch, UNITED STATES

Received: January 8, 2019; Accepted: May 2, 2019; Published: May 28, 2019

Copyright: © 2019 Zhang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the manuscript and its Supporting Information files.

Funding: WL is supported by the China Mega-Project for Infectious Diseases (No. 2018ZX10713002), National Natural Science Foundation of China (No. 81825019 and 81621005), and the Talent Program of Science and Technology of Beijing (No. Z181100006318008, Z171100001117089). HL is supported by National Natural Science Foundation of China (No. 81472005). QBL is supported by National Natural Science Foundation of China (No. 81703274) and Peking University Medicine Seed Fund for Interdisciplinary Research (BMU2018MX009). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Keywords: Bunyavirus; SFTS.


Rescue of infectious recombinant #Hazara #nairovirus from cDNA reveals the nucleocapsid protein DQVD caspase #cleavage motif performs an essential role other than cleavage (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

Rescue of infectious recombinant Hazara nairovirus from cDNA reveals the nucleocapsid protein DQVD caspase cleavage motif performs an essential role other than cleavage.

J. Fuller, R. A. Surtees, G.S. Slack, J. Mankouri, R. Hewson, J. N. Barr

DOI: 10.1128/JVI.00616-19



The Nairoviridae family of the Bunyavirales order comprises tick-borne tri-segmented negative strand RNA viruses, with several members associated with serious or fatal disease in humans and animals. A notable member is Crimean-Congo hemorrhagic fever virus (CCHFV), which is the most widely-distributed tick-borne pathogen, and associated with devastating human disease with case/fatality rates averaging 30%. Hazara virus (HAZV) is closely-related to CCHFV, sharing the same serogroup and many structural, biochemical and cellular properties. To improve understanding of HAZV and nairovirus multiplication cycles, we developed for the first time a rescue system permitting efficient recovery of infectious HAZV from cDNA. This system now allows reverse genetics analysis of nairoviruses without the need for high biosafety containment, as is required for CCHFV. We used this system to test the importance of a DQVD caspase cleavage site exposed on the apex of the HAZV nucleocapsid protein arm domain that is cleaved during HAZV infection, and for which the equivalent DEVD sequence was recently shown to be important for CCHFV growth in tick but not mammalian cells. Infectious HAZV bearing an un-cleavable DQVE sequence was rescued and exhibited equivalent growth parameters to wild-type in both mammalian and tick cells, showing this site was dispensable for virus multiplication. In contrast, substitution of the DQVD motif with the similarly un-cleavable AQVA sequence could not be rescued despite repeated efforts. Together, this work highlights the importance of this caspase cleavage site in the HAZV lifecycle, but reveals the DQVD sequence performs a critical role aside from caspase cleavage.



Hazara virus is classified within the Nairoviridae family along with Crimean-Congo hemorrhagic fever virus (CCHFV), which is one of the most lethal human pathogens in existence, requiring the highest biosafety level (BSL) containment (BSL-4). In contrast, HAZV is not associated with human disease and thus can be studied using less-restrictive BSL-2 protocols. Here, we report a system able to rescue Hazara virus (HAZV) from cDNAs, thus permitting reverse genetic interrogation of the HAZV replication cycle. We used this system to examine the role of a caspase cleavage site, DQVD, within the HAZV nucleocapsid protein that is also conserved in CCHFV. By engineering mutant viruses, we showed caspase cleavage at this site was not required for productive infection, and furthermore that this sequence performs a critical role in the virus lifecycle aside from caspase cleavage. This system will accelerate nairovirus research due to its efficiency and utility under amenable BSL-2 protocols.

Copyright © 2019 American Society for Microbiology. All Rights Reserved.

Keywords: Bunyavirus; Hazara virus; CCHF virus; Nairovirus.


#Aporé virus, a novel #mammarenavirus (#Bunyavirales: #Arenaviridae) related to highly pathogenic virus from South #America (Mem Inst Oswaldo Cruz, abstract)

[Source: Memoria do Institutos Oswaldo Cruz, full page: (LINK). Abstract, edited.]

Aporé virus, a novel mammarenavirus (Bunyavirales: Arenaviridae) related to highly pathogenic virus from South America


Jorlan Fernandes1,+, Alexandro Guterres1, Renata Carvalho de Oliveira1, Rodrigo Jardim2, Alberto Martín Rivera Dávila2, Roger Hewson3, Elba Regina Sampaio de Lemos1

1 Laboratório de Hantaviroses e Rickettsioses, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro – RJ, Brasil; 2 Laboratório de Biologia Computacional e Sistemas, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro – RJ, Brasil; 3 National Infection Service, Public Health England, Salisbury, United Kingdom

DOI: 10.1590/0074-02760180586



Here, we report the complete genome sequence of the Aporé virus (Bunyavirales: Arenaviridae), obtained from a wild rodent Oligoryzomys mattogrossae captured in Mato Grosso do Sul state, Brazil. The genome of this virus showed strong similarity to highly pathogenic mammarenavirus from South America.

key words: Oligoryzomys – mattogrossae rodent mammarenavirus – arenavirus – Aporé virus

Financial support: FIOCRUZ, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES and Conselho Nacional para o Desenvolvimento Científico e Tecnológico (CNPq), grant number 404762/2016-6.

+ Corresponding author:

Received 14 December 2018  – Accepted 29 April 2019

Keywords: Mammarenavirus; Bunyavirus; Arenavirus; Aporé virus; Brazil.