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Nuñez IA, Crane A, Crozier I, Worwa G, Kuhn JH. Treatment of highly virulent mammarenavirus infections-status quo and future directions. Expert Opin Drug Discov 2024; 19:537-551. [PMID: 38606475 PMCID: PMC11069405 DOI: 10.1080/17460441.2024.2340494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 04/04/2024] [Indexed: 04/13/2024]
Abstract
INTRODUCTION Mammarenaviruses are negative-sense bisegmented enveloped RNA viruses that are endemic in Africa, the Americas, and Europe. Several are highly virulent, causing acute human diseases associated with high case fatality rates, and are considered to be significant with respect to public health impact or bioterrorism threat. AREAS COVERED This review summarizes the status quo of treatment development, starting with drugs that are in advanced stages of evaluation in early clinical trials, followed by promising candidate medical countermeasures emerging from bench analyses and investigational animal research. EXPERT OPINION Specific therapeutic treatments for diseases caused by mammarenaviruses remain limited to the off-label use of ribavirin and transfusion of convalescent sera. Progress in identifying novel candidate medical countermeasures against mammarenavirus infection has been slow in part because of the biosafety and biosecurity requirements. However, novel methodologies and tools have enabled increasingly efficient high-throughput molecular screens of regulatory-agency-approved small-molecule drugs and led to the identification of several compounds that could be repurposed for the treatment of infection with several mammarenaviruses. Unfortunately, most of them have not yet been evaluated in vivo. The most promising treatment under development is a monoclonal antibody cocktail that is protective against multiple lineages of the Lassa virus in nonhuman primate disease models.
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Affiliation(s)
- Ivette A. Nuñez
- Integrated Research Facility at Fort Detrick, Division of
Clinical Research, National Institute of Allergy and Infectious Diseases, National
Institutes of Health, Fort Detrick, Frederick, MD21702, USA
| | - Anya Crane
- Integrated Research Facility at Fort Detrick, Division of
Clinical Research, National Institute of Allergy and Infectious Diseases, National
Institutes of Health, Fort Detrick, Frederick, MD21702, USA
| | - Ian Crozier
- Clinical Monitoring Research Program Directorate, Frederick
National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Gabriella Worwa
- Integrated Research Facility at Fort Detrick, Division of
Clinical Research, National Institute of Allergy and Infectious Diseases, National
Institutes of Health, Fort Detrick, Frederick, MD21702, USA
| | - Jens H. Kuhn
- Integrated Research Facility at Fort Detrick, Division of
Clinical Research, National Institute of Allergy and Infectious Diseases, National
Institutes of Health, Fort Detrick, Frederick, MD21702, USA
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Viral agents (2nd section). Transfusion 2024; 64 Suppl 1:S19-S207. [PMID: 38394038 DOI: 10.1111/trf.17630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 12/02/2023] [Indexed: 02/25/2024]
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Keating PM, Schifano NP, Wei X, Kong MY, Lee J. pH-dependent conformational change within the Lassa virus transmembrane domain elicits efficient membrane fusion. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184233. [PMID: 37734457 DOI: 10.1016/j.bbamem.2023.184233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/05/2023] [Accepted: 09/16/2023] [Indexed: 09/23/2023]
Abstract
Lassa virus (LASV) is the most prevalent member of the arenavirus family and the causative agent of Lassa fever, a viral hemorrhagic fever. Although there are annual outbreaks in West Africa, and recently isolated cases worldwide, there are no current therapeutics or vaccines, which poses LASV as a significant global public health threat. One of the key steps in LASV infection is the delivery of its genetic material by fusing its viral membrane with the host cell membrane. This process is facilitated by significant conformational changes within glycoprotein 2 (GP2), yielding distinct prefusion and postfusion structural states. However, structural information is missing to understand the changes that occur in the transmembrane domain during the fusion process. Here, we used CD and NMR spectroscopy to show that the transmembrane domain has pH-dependent conformational changes that result in an extension of the alpha helix at the N-terminal end. Proline mutants of key residues in that region prevent the helical extension, as seen in CD and NMR. We developed a modified lipid mixing assay to study the importance of this extension on the function of GP2. Our assay shows that membrane fusion efficiency is optimal at low pH values but introducing the proline mutants results in lower fusion efficiency. These results indicate that these pH-dependent conformational changes are important to the fusion mechanism. This information can be used to design therapeutics to combat Lassa virus infections and prevent its potential spread.
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Affiliation(s)
- Patrick M Keating
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Nicholas P Schifano
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Xinrui Wei
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Matthew Y Kong
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Jinwoo Lee
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA.
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Keating PM, Pennington HN, Collins SD, Lee J. Purification and characterization of the Lassa virus transmembrane domain. Biochem Biophys Rep 2022; 33:101409. [PMID: 36583076 PMCID: PMC9792740 DOI: 10.1016/j.bbrep.2022.101409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022] Open
Abstract
Lassa virus (LASV) is the most prevalent arenavirus afflicting humans and has high potential to become a threat to global public health. The transmembrane domain (TM) of the LASV glycoprotein complex forms critical interactions with the LASV stable signal peptide that are important for the maturation and fusion activity of the virus. A further study of the structure-based molecular mechanisms is required to understand the role of the TM in the lifecycle of LASV in greater detail. However, it is challenging to obtain the TM in high quantity and purity due to its hydrophobic nature which results in solubility issues that makes it prone to aggregation in typical buffer systems. Here, we designed a purification and detergent screen protocol for the highly insoluble TM to enhance the yield and purity for structural studies. Based on the detergents tested, the TM had the highest incorporation in LMPG. Circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy were utilized to confirm the best detergent system for structural studies. Through CD spectroscopy, we were able to characterize the secondary structure of the TM as largely alpha-helical, while NMR spectroscopy showed a well-structured and stable TM in LMPG. From these results, LMPG was determined to be the optimal detergent for further structural studies.
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Welch SR, Genzer SC, Coleman-McCray JD, Harmon JR, Scholte FEM, Montgomery JM, Spiropoulou CF, Spengler JR. Viral RNA and infectious virus in mucosal specimens from guinea pigs modelling early phases of lethal and non-lethal Lassa fever. Emerg Microbes Infect 2022; 11:1390-1393. [PMID: 35481464 PMCID: PMC9132395 DOI: 10.1080/22221751.2022.2071637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Lassa fever (LF) is endemic to broad regions of West Africa. Infection with Lassa virus (LASV), the etiologic agent of LF, results in a spectrum of clinical signs in humans, including severe and lethal hemorrhagic disease. Person-to-person transmission occurs through direct contact with body fluids or contaminated bedding and clothing. To investigate transmission risk in acute LASV infection, we evaluated viral RNA and infectious virus obtained from conjunctival, nasal, oral, genital, and rectal swab specimens from guinea pigs modelling lethal and non-lethal LF. Viral RNA and infectious virus were detected in all specimen types beginning 8 days post infection, prior to onset of fever. In the pre-clinical and clinical period, virus was isolated from a subset of nasal, oral, genital, and rectal swabs, and from all conjunctival swabs. Overall, conjunctival and nasal specimens most frequently yielded infectious virus. These findings indicate mucosal transmission risk based on virus isolation from various sites early in infection and support potential utility of minimally invasive specimen evaluation by RT-qPCR for LASV diagnostics.
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Affiliation(s)
- Stephen R Welch
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Sarah C Genzer
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - JoAnn D Coleman-McCray
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jessica R Harmon
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Florine E M Scholte
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Joel M Montgomery
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Christina F Spiropoulou
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jessica R Spengler
- Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, GA, USA
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Thielebein A, Ighodalo Y, Taju A, Olokor T, Omiunu R, Esumeh R, Ebhodaghe P, Ekanem A, Igenegbale G, Giwa R, Renevey A, Hinzmann J, Müller J, Pallasch E, Pahlmann M, Guedj J, Nwatuzor J, Femi Babatunde O, Adomeh DI, Asogun D, Akpede N, Okogbenin S, Günther S, Oestereich L, Duraffour S, Ogbaini-Emovon E. Virus persistence after recovery from acute Lassa fever in Nigeria: a 2-year interim analysis of a prospective longitudinal cohort study. THE LANCET MICROBE 2022; 3:e32-e40. [DOI: 10.1016/s2666-5247(21)00178-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 05/22/2021] [Accepted: 06/30/2021] [Indexed: 12/13/2022] Open
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