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The Journal of Infectious Diseases Oct 2023Viruses in the family Filoviridae, including the commonly known Ebola (EBOV) and Marburg (MARV) viruses, can cause severe hemorrhagic fever in humans and nonhuman... (Review)
Review
Viruses in the family Filoviridae, including the commonly known Ebola (EBOV) and Marburg (MARV) viruses, can cause severe hemorrhagic fever in humans and nonhuman primates. Sporadic outbreaks of filovirus disease occur in sub-Saharan Africa with reported case fatality rates ranging from 25% to 90%. The high mortality and increasing frequency and magnitude of recent outbreaks along with the increased potential for spread from rural to urban areas highlight the importance of pandemic preparedness for these viruses. Despite their designation as high-priority pathogens, numerous scientific gaps exist in critical areas. In this review, these gaps and an assessment of potential prototype pathogen candidates are presented for this important virus family.
Topics: Animals; Humans; Filoviridae; Ebolavirus; Hemorrhagic Fever, Ebola; Marburgvirus; Disease Outbreaks
PubMed: 37849404
DOI: 10.1093/infdis/jiad362 -
Scientific Reports Jul 2023Lloviu cuevavirus (LLOV) was the first identified member of Filoviridae family outside the Ebola and Marburgvirus genera. A massive die-off of Schreibers's bats...
Lloviu cuevavirus (LLOV) was the first identified member of Filoviridae family outside the Ebola and Marburgvirus genera. A massive die-off of Schreibers's bats (Miniopterus schreibersii) in the Iberian Peninsula in 2002 led to its initial discovery. Recent studies with recombinant and wild-type LLOV isolates confirmed the zoonotic nature of the virus in vitro. We examined bat samples from Italy for the presence of LLOV in an area outside of the currently known distribution range of the virus. We detected one positive sample from 2020, sequenced the complete coding region of the viral genome and established an infectious isolate of the virus. In addition, we performed the first comprehensive evolutionary analysis of the virus, using the Spanish, Hungarian and the Italian sequences. The most important achievement of this study is the establishment of an additional infectious LLOV isolate from a bat sample using the SuBK12-08 cells, demonstrating that this cell line is highly susceptible to LLOV infection and confirming the previous observation that these bats are effective hosts of the virus in nature. This result further strengthens the role of bats as the natural hosts for zoonotic filoviruses.
Topics: Animals; Chiroptera; Filoviridae; Marburgvirus; Cell Line; Italy; Phylogeny
PubMed: 37443182
DOI: 10.1038/s41598-023-38364-7 -
PLoS Pathogens Aug 2023Ebola (EBOV) and Marburg viruses (MARV) cause severe hemorrhagic fever associated with high mortality rates in humans. A better understanding of filovirus-host...
Ebola (EBOV) and Marburg viruses (MARV) cause severe hemorrhagic fever associated with high mortality rates in humans. A better understanding of filovirus-host interactions that regulate the EBOV and MARV lifecycles can provide biological and mechanistic insight critical for therapeutic development. EBOV glycoprotein (eGP) and MARV glycoprotein (mGP) mediate entry into host cells primarily by actin-dependent macropinocytosis. Here, we identified actin-binding cytoskeletal crosslinking proteins filamin A (FLNa) and B (FLNb) as important regulators of both EBOV and MARV entry. We found that entry of pseudotype psVSV-RFP-eGP, infectious recombinant rVSV-eGP-mCherry, and live authentic EBOV and MARV was inhibited in filamin A knockdown (FLNaKD) cells, but was surprisingly enhanced in filamin B knockdown (FLNbKD) cells. Mechanistically, our findings suggest that differential regulation of macropinocytosis by FLNa and FLNb likely contributes to their specific effects on EBOV and MARV entry. This study is the first to identify the filamin family of proteins as regulators of EBOV and MARV entry. These findings may provide insight into the development of new countermeasures to prevent EBOV and MARV infections.
Topics: Humans; Filamins; Ebolavirus; Actins; Hemorrhagic Fever, Ebola; Marburgvirus; Glycoproteins
PubMed: 37585478
DOI: 10.1371/journal.ppat.1011595 -
The Journal of Infectious Diseases Nov 2023Filoviruses, including ebolaviruses and marburgviruses, can cause severe and often fatal disease in humans. Over the past several years, antibody therapy has emerged as...
Filoviruses, including ebolaviruses and marburgviruses, can cause severe and often fatal disease in humans. Over the past several years, antibody therapy has emerged as a promising strategy for the treatment of filovirus disease. Here, we describe 2 distinct cross-reactive monoclonal antibodies (mAbs) isolated from mice immunized with recombinant vesicular stomatitis virus-based filovirus vaccines. Both mAbs recognized the glycoproteins of multiple different ebolaviruses and exhibited broad but differential in vitro neutralization activities against these viruses. By themselves, each mAb provided partial to full protection against Ebola virus in mice, and in combination, the mAbs provided 100% protection against Sudan virus challenge in guinea pigs. This study identified novel mAbs that were elicited through immunization and able to provide protection from ebolavirus infection, thus enriching the pool of candidate therapeutics for treating Ebola disease.
Topics: Humans; Animals; Guinea Pigs; Mice; Hemorrhagic Fever, Ebola; Ebolavirus; Antibodies, Monoclonal; Combined Antibody Therapeutics; Antibodies, Neutralizing; Antibodies, Viral
PubMed: 37288609
DOI: 10.1093/infdis/jiad205 -
Nature Communications Oct 2023Marburg and Ebola filoviruses are two of the deadliest infectious agents and several outbreaks have occurred in the last decades. Although several receptors and...
Marburg and Ebola filoviruses are two of the deadliest infectious agents and several outbreaks have occurred in the last decades. Although several receptors and co-receptors have been reported for Ebola virus, key host factors remain to be elucidated. In this study, using a haploid cell screening platform, we identify the guanine nucleotide exchange factor CCZ1 as a key host factor in the early stage of filovirus replication. The critical role of CCZ1 for filovirus infections is validated in 3D primary human hepatocyte cultures and human blood-vessel organoids, both critical target sites for Ebola and Marburg virus tropism. Mechanistically, CCZ1 controls early to late endosomal trafficking of these viruses. In addition, we report that CCZ1 has a role in the endosomal trafficking of endocytosis-dependent SARS-CoV-2 infections, but not in infections by Lassa virus, which enters endo-lysosomal trafficking at the late endosome stage. Thus, we have identified an essential host pathway for filovirus infections in cell lines and engineered human target tissues. Inhibition of CCZ1 nearly completely abolishes Marburg and Ebola infections. Thus, targeting CCZ1 could potentially serve as a promising drug target for controlling infections caused by various viruses, such as SARS-CoV-2, Marburg, and Ebola.
Topics: Animals; Humans; Ebolavirus; Hemorrhagic Fever, Ebola; Lysosomes; Marburg Virus Disease; Marburgvirus; Vesicular Transport Proteins
PubMed: 37880247
DOI: 10.1038/s41467-023-42526-6 -
Viruses Aug 2023A new filovirus named Měnglà virus was found in bats in southern China in 2015. This species has been assigned to the new genus and has only been detected in China....
A new filovirus named Měnglà virus was found in bats in southern China in 2015. This species has been assigned to the new genus and has only been detected in China. In this article, we report the detection of filoviruses in bats captured in Vietnam. We studied 248 bats of 15 species caught in the provinces of Lai Chau and Son La in northern Vietnam and in the province of Dong Thap in the southern part of the country. Filovirus RNA was found in four and one from Lai Chau Province. Phylogenetic analysis of the polymerase gene fragment showed that three positive samples belong to , and two samples form a separate clade closer to . An enzyme-linked immunosorbent assay showed that 9% of , 13% of , and 10% of bats had antibodies to the glycoprotein of marburgviruses.
Topics: Animals; Filoviridae; Chiroptera; Vietnam; Phylogeny; Marburgvirus
PubMed: 37766193
DOI: 10.3390/v15091785 -
Autophagy Oct 2023Ebola virus (EBOV) and Marburg virus (MARV) are zoonotic, virulent pathogens that cause sporadic and global outbreaks of severe hemorrhagic fever. Reemergence of these...
Ebola virus (EBOV) and Marburg virus (MARV) are zoonotic, virulent pathogens that cause sporadic and global outbreaks of severe hemorrhagic fever. Reemergence of these filoviruses remains a global public health threat, highlighting the need for novel countermeasures to control and treat future disease outbreaks. The EBOV VP40 matrix protein drives virion assembly and egress. We recently reported that BAG3 and HSPA/HSP70, two central components of chaperone-assisted selective autophagy (CASA), target VP40 for autophagic sequestration and degradation, thereby inhibiting virus egress and spread. In addition, we found that expression of the EBOV glycoprotein (GP) activates MTORC1, the gateway regulator of autophagy. Notably, pharmacological suppression of MTORC1 signaling by rapamycin activates autophagy and blocks filovirus egress. These findings highlight the MTORC1-CASA axis as a regulator of filovirus egress and suggest new opportunities for antiviral development and intervention.
Topics: Autophagy; Ebolavirus; Marburgvirus
PubMed: 36763514
DOI: 10.1080/15548627.2023.2178781 -
The Lancet. Infectious Diseases May 2024The 2023 Marburg virus disease outbreaks in Equatorial Guinea and Tanzania highlighted the importance of better understanding this lethal pathogen. We did a systematic... (Review)
Review
The 2023 Marburg virus disease outbreaks in Equatorial Guinea and Tanzania highlighted the importance of better understanding this lethal pathogen. We did a systematic review (PROSPERO CRD42023393345) of peer-reviewed articles reporting historical outbreaks, modelling studies, and epidemiological parameters focused on Marburg virus disease. We searched PubMed and Web of Science from database inception to March 31, 2023. Two reviewers evaluated all titles and abstracts with consensus-based decision making. To ensure agreement, 13 (31%) of 42 studies were double-extracted and a custom-designed quality assessment questionnaire was used for risk of bias assessment. We present detailed information on 478 reported cases and 385 deaths from Marburg virus disease. Analysis of historical outbreaks and seroprevalence estimates suggests the possibility of undetected Marburg virus disease outbreaks, asymptomatic transmission, or cross-reactivity with other pathogens, or a combination of these. Only one study presented a mathematical model of Marburg virus transmission. We estimate an unadjusted, pooled total random effect case fatality ratio of 61·9% (95% CI 38·8-80·6; I=93%). We identify epidemiological parameters relating to transmission and natural history, for which there are few estimates. This systematic review and the accompanying database provide a comprehensive overview of Marburg virus disease epidemiology and identify key knowledge gaps, contributing crucial information for mathematical models to support future Marburg virus disease epidemic responses.
Topics: Marburg Virus Disease; Humans; Disease Outbreaks; Marburgvirus; Animals; Models, Theoretical; Seroepidemiologic Studies
PubMed: 38040006
DOI: 10.1016/S1473-3099(23)00515-7 -
ELife Mar 2024Marburg virus (MARV) is one of the filovirus species that cause deadly hemorrhagic fever in humans, with mortality rates up to 90%. Neutralizing antibodies represent...
Marburg virus (MARV) is one of the filovirus species that cause deadly hemorrhagic fever in humans, with mortality rates up to 90%. Neutralizing antibodies represent ideal candidates to prevent or treat virus disease. However, no antibody has been approved for MARV treatment to date. In this study, we identified a novel human antibody named AF-03 that targeted MARV glycoprotein (GP). AF-03 possessed a high binding affinity to MARV GP and showed neutralizing and protective activities against the pseudotyped MARV in vitro and in vivo. Epitope identification, including molecular docking and experiment-based analysis of mutated species, revealed that AF-03 recognized the Niemann-Pick C1 (NPC1) binding domain within GP1. Interestingly, we found the neutralizing activity of AF-03 to pseudotyped Ebola viruses (EBOV, SUDV, and BDBV) harboring cleaved GP instead of full-length GP. Furthermore, NPC2-fused AF-03 exhibited neutralizing activity to several filovirus species and EBOV mutants via binding to CI-MPR. In conclusion, this work demonstrates that AF-03 represents a promising therapeutic cargo for filovirus-caused disease.
Topics: Humans; Marburgvirus; Antibodies, Viral; Molecular Docking Simulation; Glycoproteins; Hemorrhagic Fever, Ebola; Ebolavirus
PubMed: 38526940
DOI: 10.7554/eLife.91181