scholarly journals Development of Reverse Genetics for the Prototype New World Mammarenavirus Tacaribe Virus

2020 ◽  
Vol 94 (19) ◽  
Author(s):  
Chengjin Ye ◽  
Juan Carlos de la Torre ◽  
Luis Martínez-Sobrido
Keyword(s):  
New World ◽  
Reverse Genetics ◽  
Viral Infections ◽  
Hemorrhagic Fever ◽  
Vaccine Vector ◽  
Live Attenuated Vaccine ◽  
Attenuated Vaccine ◽  
Argentine Hemorrhagic Fever ◽  
Tacaribe Virus ◽  
First Time

ABSTRACT The New World mammarenavirus Tacaribe virus (TCRV) has been isolated from fruit bats, mosquitoes, and ticks, whereas all other known New World mammarenaviruses are maintained in rodents. TCRV has not been linked to human disease, but it has been shown to protect against Argentine hemorrhagic fever-like disease in marmosets infected with the New World mammarenavirus Junín virus (JUNV), indicating the potential of TCRV as a live-attenuated vaccine for the treatment of Argentine hemorrhagic fever. Implementation of TCRV as a live-attenuated vaccine or a vaccine vector would be facilitated by the establishment of reverse genetics systems for the genetic manipulation of the TCRV genome. In this study, we developed, for the first time, reverse genetics approaches for the generation of recombinant TCRV (rTCRV). We successfully rescued a wild-type (WT) rTCRV (a trisegmented form of TCRV expressing two reporter genes [r3TCRV]) and a bisegmented TCRV expressing a single reporter gene from a bicistronic viral mRNA (rTCRV/GFP). These reverse genetics approaches represent an excellent tool to investigate the biology of TCRV and to explore its potential use as a live-attenuated vaccine or a vaccine vector for the treatment of other viral infections. Notably, we identified a 39-nucleotide (nt) deletion (Δ39) in the noncoding intergenic region (IGR) of the viral large (L) segment that is required for optimal virus multiplication. Accordingly, an rTCRV containing this 39-nt deletion in the L-IGR (rTCRV/Δ39) exhibited decreased viral fitness in cultured cells, suggesting the feasibility of using this deletion in the L-IGR as an approach to attenuate TCRV, and potentially other mammarenaviruses, for their implementation as live-attenuated vaccines or vaccine vectors. IMPORTANCE To date, no Food and Drug Administration (FDA)-approved vaccines are available to combat hemorrhagic fever caused by mammarenavirus infections in humans. Treatment of mammarenavirus infections is limited to the off-label use of ribavirin, which is partially effective and associated with significant side effects. Tacaribe virus (TCRV), the prototype member of the New World mammarenaviruses, is nonpathogenic in humans but able to provide protection against Junín virus (JUNV), the causative agent of Argentine hemorrhagic fever, demonstrating the feasibility of using TCRV as a live-attenuated vaccine vector for the treatment of JUNV and potentially other viral infections. Here, we describe for the first time the feasibility of generating recombinant TCRV (rTCRV) using reverse genetics approaches, which paves the way to study the biology of TCRV and also its potential use as a live-attenuated vaccine or a vaccine vector for the treatment of mammarenavirus and/or other viral infections in humans.

scholarly journals The Glycoprotein of the Live-Attenuated Junin Virus Vaccine Strain Induces Endoplasmic Reticulum Stress and Forms Aggregates prior to Degradation in the Lysosome

2020 ◽  
Vol 94 (8) ◽  
Author(s):  
John T. Manning ◽  
Nadya E. Yun ◽  
Alexey V. Seregin ◽  
Takaaki Koma ◽  
Rachel A. Sattler ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Vaccine Strain ◽  
Hemorrhagic Fever ◽  
Wild Type ◽  
Live Attenuated Vaccine ◽  
Hemorrhagic Fevers ◽  
Attenuated Vaccine ◽  
Argentine Hemorrhagic Fever ◽  
Viral Hemorrhagic Fevers ◽  
Junín Virus

ABSTRACT Argentine hemorrhagic fever is a potentially lethal disease that is caused by Junin virus (JUNV). There are currently around 5 million individuals at risk of infection within regions of endemicity in Argentina. The live attenuated vaccine strain Candid #1 (Can) is approved for use in regions of endemicity and has substantially decreased the number of annual Argentine hemorrhagic fever (AHF) cases. The glycoprotein (GPC) gene is primarily responsible for attenuation of the Can strain, and we have shown that the absence of an N-linked glycosylation motif in the subunit G1 of the glycoprotein complex of Can, which is otherwise present in the wild-type pathogenic JUNV, causes GPC retention in the endoplasmic reticulum (ER). Here, we show that Can GPC aggregates in the ER of infected cells, forming incorrect cross-chain disulfide bonds, which results in impaired GPC processing into G1 and G2. The GPC fails to cleave into its G1 and G2 subunits and is targeted for degradation within lysosomes. Cells infected with the wild-type Romero (Rom) strain do not produce aggregates that are observed in Can infection, and the stress on the ER remains minimal. While the mutation of the N-linked glycosylation motif (T168A) is primarily responsible for the formation of aggregates, other mutations within G1 that occurred earlier in the passage history of the Can strain also contribute to aggregation of the GPC within the ER. IMPORTANCE The development of vaccines and therapeutics to combat viral hemorrhagic fevers remains a top priority within the Implementation Plan of the U.S. Department of Health and Human Services Public Health Emergency Medical Countermeasures Enterprise. The Can strain, derived from the pathogenic XJ strain of JUNV, has been demonstrated to be both safe and protective against AHF. While the vaccine strain is approved for use in regions of endemicity within Argentina, the mechanisms of Can attenuation have not been elucidated. A better understanding of the viral genetic determinants of attenuation will improve our understanding of the mechanisms contributing to disease pathogenesis and provide critical information for the rational design of live attenuated vaccine candidates for other viral hemorrhagic fevers.

scholarly journals Protective Efficacy of a Live Attenuated Vaccine against Argentine Hemorrhagic Fever

1998 ◽  
Vol 177 (2) ◽  
pp. 277-283 ◽  
Author(s):  
Julio I. Maiztegui ◽  
Kelly T. McKee, Jr. ◽  
Julio G. Barrera Oro ◽  
Lee H. Harrison ◽  
Paul H. Gibbs ◽  
...  
Keyword(s):  
Protective Efficacy ◽  
Hemorrhagic Fever ◽  
Live Attenuated Vaccine ◽  
Attenuated Vaccine ◽  
Argentine Hemorrhagic Fever

Long-term protection against Argentine hemorrhagic fever in Tacaribe virus infected marmosets: Virologic and histopathologic findings

1988 ◽  
Vol 24 (2) ◽  
pp. 229-236 ◽  
Author(s):  
Sergio R. Samoilovich ◽  
Miguel A. Calello ◽  
Rubén P. Laguens ◽  
Mercedes C. Weissenbacher
Keyword(s):  
Hemorrhagic Fever ◽  
Argentine Hemorrhagic Fever ◽  
Tacaribe Virus ◽  
Histopathologic Findings

scholarly journals Structural basis for recognition and regulation of arenavirus polymerase L by Z protein

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Huiling Kang ◽  
Jingyuan Cong ◽  
Chenlong Wang ◽  
Wenxin Ji ◽  
Yuhui Xin ◽  
...  
Keyword(s):  
Rational Design ◽  
Viral Infections ◽  
Hemorrhagic Fever ◽  
Structural Basis ◽  
Exit Site ◽  
L Protein ◽  
Argentine Hemorrhagic Fever ◽  
L Proteins ◽  
Z Protein

AbstractJunin virus (JUNV) causes Argentine hemorrhagic fever, a debilitating human disease of high mortality rates and a great risk to public health worldwide. Studying the L protein that replicates and transcribes the genome of JUNV, and its regulator Z protein should provide critical clues to identify therapeutic targets for disrupting the life cycle of JUNV. Here we report the 3.54 Å cryo-EM structure of the JUNV L protein complexed with regulator Z protein. JUNV L structure reveals a conserved architecture containing signature motifs found in other L proteins. Structural analysis shows that L protein is regulated by binding of Z protein at the RNA product exit site. Based on these findings, we propose a model for the role of Z protein as a switch to turn on/off the viral RNA synthesis via its interaction with L protein. Our work unveils the mechanism of JUNV transcription, replication and regulation, which provides a framework for the rational design of antivirals for combating viral infections.

scholarly journals Development of a ΔglnA Balanced Lethal Plasmid System for Expression of Heterologous Antigens by Attenuated Vaccine Vector Strains of Vibrio cholerae

2000 ◽  
Vol 68 (1) ◽  
pp. 221-226 ◽  
Author(s):  
Edward T. Ryan ◽  
Thomas I. Crean ◽  
Sims K. Kochi ◽  
Manohar John ◽  
Angel A. Luciano ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vibrio Cholerae ◽  
Antigen Expression ◽  
Single Copy ◽  
Vaccine Vector ◽  
Live Attenuated Vaccine ◽  
Primary Inoculation ◽  
Attenuated Vaccine ◽  
Growth Deficiency

ABSTRACT We have previously shown that more prominent immune responses are induced to antigens expressed from multicopy plasmids in live attenuated vaccine vector strains of Vibrio cholerae than to antigens expressed from single-copy genes on the V. cholerae chromosome. Here, we report the construction of a ΔglnA derivative of V. cholerae vaccine strain Peru2. This mutant strain, Peru2ΔglnA, is unable to grow on medium that does not contain glutamine; this growth deficiency is complemented by pKEK71-NotI, a plasmid containing a complete copy of the Salmonella typhimurium glnA gene, or by pTIC5, a derivative of pKEK71-NotI containing a 1.8-kbp fragment that directs expression of CtxB with a 12-amino-acid epitope of the serine-rich Entamoeba histolytica protein fused to the amino terminus. Strain Peru2ΔglnA(pTIC5) produced 10-fold more SREHP-12-CtxB in supernatants than did ETR3, a Peru2-derivative strain containing the same fragment inserted on the chromosome. To assess immune responses to antigens expressed by this balanced lethal system in vivo, we inoculated germfree mice on days 0, 14, 28, and 42 with Peru2ΔglnA, Peru2ΔglnA(pKEK71-NotI), Peru2(pTIC5), Peru2ΔglnA(pTIC5), or ETR3. All V. cholerae strains were recoverable from stool for 8 to 12 days after primary inoculation, including Peru2ΔglnA; strains containing plasmids continued to harbor pKEK71-NotI or pTIC5 for 8 to 10 days after primary inoculation. Animals were sacrificed on day 56, and serum, stool and biliary samples were analyzed for immune responses. Vibriocidal antibody responses, reflective of in vivo colonization, were equivalent in all groups of animals. However, specific anti-CtxB immune responses in serum (P ≤ 0.05) and bile (P ≤ 0.001) were significantly higher in animals that received Peru2ΔglnA(pTIC5) than in those that received ETR3, confirming the advantage of higher-level antigen expression in vivo. The development of this balanced lethal system thus permits construction and maintenance of vaccine and vector strains of V. cholerae that express high levels of immunogenic antigens from plasmid vectors without the need for antibiotic selection pressure.

Tacaribe virus: A new alternative for Argentine hemorrhagic fever vaccine

1987 ◽  
Vol 23 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Guadalupe Carballal ◽  
Miguel A. Calello ◽  
Rubén P. Laguens ◽  
Mercedes C. Weissenbacher
Keyword(s):  
Hemorrhagic Fever ◽  
Argentine Hemorrhagic Fever ◽  
Tacaribe Virus

scholarly journals Therapy for Argentine hemorrhagic fever in nonhuman primates with a humanized monoclonal antibody

2021 ◽  
Vol 118 (11) ◽  
pp. e2023332118
Author(s):  
Larry Zeitlin ◽  
Robert W. Cross ◽  
Joan B. Geisbert ◽  
Viktoriya Borisevich ◽  
Krystle N. Agans ◽  
...  
Keyword(s):  
Large Scale ◽  
Viral Infections ◽  
Hemorrhagic Fever ◽  
Viral Pathogens ◽  
Monkey Model ◽  
Argentine Hemorrhagic Fever ◽  
Safety Risks ◽  
Humanized Monoclonal Antibody ◽  
Approved Drugs ◽  
Guinea Pig Model

The COVID-19 pandemic has reemphasized the need to identify safe and scalable therapeutics to slow or reverse symptoms of disease caused by newly emerging and reemerging viral pathogens. Recent clinical successes of monoclonal antibodies (mAbs) in therapy for viral infections demonstrate that mAbs offer a solution for these emerging biothreats. We have explored this with respect to Junin virus (JUNV), an arenavirus classified as a category A high-priority agent and the causative agent of Argentine hemorrhagic fever (AHF). There are currently no Food and Drug Administration-approved drugs available for preventing or treating AHF, although immune plasma from convalescent patients is used routinely to treat active infections. However, immune plasma is severely limited in quantity, highly variable in quality, and poses significant safety risks including the transmission of transfusion-borne diseases. mAbs offer a highly specific and consistently potent alternative to immune plasma that can be manufactured at large scale. We previously described a chimeric mAb, cJ199, that provided protection in a guinea pig model of AHF. To adapt this mAb to a format more suitable for clinical use, we humanized the mAb (hu199) and evaluated it in a cynomolgus monkey model of AHF with two JUNV isolates, Romero and Espindola. While untreated control animals experienced 100% lethality, all animals treated with hu199 at 6 d postinoculation (dpi) survived, and 50% of animals treated at 8 dpi survived. mAbs like hu199 may offer a safer, scalable, and more reproducible alternative to immune plasma for rare viral diseases that have epidemic potential.

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