1
|
Alkan C, Jurado-Cobena E, Ikegami T. Advancements in Rift Valley fever vaccines: a historical overview and prospects for next generation candidates. NPJ Vaccines 2023; 8:171. [PMID: 37925544 PMCID: PMC10625542 DOI: 10.1038/s41541-023-00769-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 10/18/2023] [Indexed: 11/06/2023] Open
Abstract
Rift Valley fever (RVF) is a zoonotic viral disease transmitted by mosquitoes and causes abortion storms, fetal malformations, and newborn animal deaths in livestock ruminants. In humans, RVF can manifest as hemorrhagic fever, encephalitis, or retinitis. Outbreaks of RVF have been occurring in Africa since the early 20th century and continue to pose a threat to both humans and animals in various regions such as Africa, Madagascar, the Comoros, Saudi Arabia, and Yemen. The development of RVF vaccines is crucial in preventing mortality and morbidity and reducing the spread of the virus. While several veterinary vaccines have been licensed in endemic countries, there are currently no licensed RVF vaccines for human use. This review provides an overview of the existing RVF vaccines, as well as potential candidates for future studies on RVF vaccine development, including next-generation vaccines that show promise in combating the disease in both humans and animals.
Collapse
Affiliation(s)
- Cigdem Alkan
- Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
| | - Eduardo Jurado-Cobena
- Department of Microbiology and Immunology, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA.
- The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA.
- The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston, 301 University Blvd, Galveston, TX, 77555, USA.
| |
Collapse
|
2
|
Wei HH, Zheng L, Wang Z. mRNA therapeutics: New vaccination and beyond. FUNDAMENTAL RESEARCH 2023; 3:749-759. [PMID: 38933291 PMCID: PMC10017382 DOI: 10.1016/j.fmre.2023.02.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 02/14/2023] [Accepted: 02/28/2023] [Indexed: 03/18/2023] Open
Abstract
The idea of mRNA therapy had been conceived for decades before it came into reality during the Covid-19 pandemic. The mRNA vaccine emerges as a powerful and general tool against new viral infections, largely due to its versatility and rapid development. In addition to prophylactic vaccines, mRNA technology also offers great promise for new applications as a versatile drug modality. However, realizing the conceptual potential faces considerable challenges, such as minimal immune stimulation, high and long-term expression, and efficient delivery to target cells and tissues. Here we review the applications of mRNA-based therapeutics, with emphasis on the innovative design and future challenges/solutions. In addition, we also discuss the next generation of mRNA therapy, including circular mRNA and self-amplifying RNAs. We aim to provide a conceptual overview and outlook on mRNA therapeutics beyond prophylactic vaccines.
Collapse
Affiliation(s)
- Huan-Huan Wei
- Bio-med Big Data Center, CAS Key Laboratory of Computational Biology, CAS Shanghai Institute of Nutrition and Health, Shanghai 200032, China
| | | | - Zefeng Wang
- Bio-med Big Data Center, CAS Key Laboratory of Computational Biology, CAS Shanghai Institute of Nutrition and Health, Shanghai 200032, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences (CAS), Beijing 100049, China
| |
Collapse
|
3
|
Hong B, Sahu U, Mullarkey MP, Hong E, Pei G, Yan Y, Otani Y, Banasavadi-Siddegowda Y, Fan H, Zhao Z, Yu J, Caligiuri MA, Kaur B. PKR induces TGF-β and limits oncolytic immune therapy. J Immunother Cancer 2023; 11:jitc-2022-006164. [PMID: 36796878 PMCID: PMC9936322 DOI: 10.1136/jitc-2022-006164] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2023] [Indexed: 02/18/2023] Open
Abstract
BACKGROUND Mammalian cells have developed multiple intracellular mechanisms to defend against viral infections. These include RNA-activated protein kinase (PKR), cyclic GMP-AMP synthase and stimulation of interferon genes (cGAS-STING) and toll-like receptor-myeloid differentiation primary response 88 (TLR-MyD88). Among these, we identified that PKR presents the most formidable barrier to oncolytic herpes simplex virus (oHSV) replication in vitro. METHODS To elucidate the impact of PKR on host responses to oncolytic therapy, we generated a novel oncolytic virus (oHSV-shPKR) which disables tumor intrinsic PKR signaling in infected tumor cells. RESULTS As anticipated, oHSV-shPKR resulted in suppression of innate antiviral immunity and improves virus spread and tumor cell lysis both in vitro and in vivo. Single cell RNA sequencing combined with cell-cell communication analysis uncovered a strong correlation between PKR activation and transforming growth factor beta (TGF-ß) immune suppressive signaling in both human and preclinical models. Using a murine PKR targeting oHSV, we found that in immune-competent mice this virus could rewire the tumor immune microenvironment to increase the activation of antigen presentation and enhance tumor antigen-specific CD8 T cell expansion and activity. Further, a single intratumoral injection of oHSV-shPKR significantly improved the survival of mice bearing orthotopic glioblastoma. To our knowledge, this is the first report to identify dual and opposing roles of PKR wherein PKR activates antivirus innate immunity and induces TGF-ß signaling to inhibit antitumor adaptive immune responses. CONCLUSIONS Thus, PKR represents the Achilles heel of oHSV therapy, restricting both viral replication and antitumor immunity, and an oncolytic virus that can target this pathway significantly improves response to virotherapy.
Collapse
Affiliation(s)
- Bangxing Hong
- Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Upasana Sahu
- Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Matthew P Mullarkey
- Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Evan Hong
- Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Guangsheng Pei
- Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Yuanqing Yan
- Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Yoshihiro Otani
- Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Yeshavanth Banasavadi-Siddegowda
- Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Huihui Fan
- Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Zhongming Zhao
- Center for Precision Health, School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Jianhua Yu
- Department of Immuno-Oncology, City of Hope National Medical Center, Duarte, California, USA
| | - Michael A Caligiuri
- Department of Immuno-Oncology, City of Hope National Medical Center, Duarte, California, USA
| | - Balveen Kaur
- Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| |
Collapse
|
4
|
Nielsen SS, Alvarez J, Bicout DJ, Calistri P, Depner K, Drewe JA, Garin-Bastuji B, Rojas JLG, Schmidt CG, Michel V, Chueca MÁM, Roberts HC, Sihvonen LH, Stahl K, Calvo AV, Viltrop A, Winckler C, Bett B, Cetre-Sossah C, Chevalier V, Devos C, Gubbins S, Monaco F, Sotiria-Eleni A, Broglia A, Abrahantes JC, Dhollander S, Stede YVD, Zancanaro G. Rift Valley Fever - epidemiological update and risk of introduction into Europe. EFSA J 2020; 18:e06041. [PMID: 33020705 PMCID: PMC7527653 DOI: 10.2903/j.efsa.2020.6041] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Rift Valley fever (RVF) is a vector-borne disease transmitted by a broad spectrum of mosquito species, especially Aedes and Culex genus, to animals (domestic and wild ruminants and camels) and humans. Rift Valley fever is endemic in sub-Saharan Africa and in the Arabian Peninsula, with periodic epidemics characterised by 5-15 years of inter-epizootic periods. In the last two decades, RVF was notified in new African regions (e.g. Sahel), RVF epidemics occurred more frequently and low-level enzootic virus circulation has been demonstrated in livestock in various areas. Recent outbreaks in a French overseas department and some seropositive cases detected in Turkey, Tunisia and Libya raised the attention of the EU for a possible incursion into neighbouring countries. The movement of live animals is the most important pathway for RVF spread from the African endemic areas to North Africa and the Middle East. The movement of infected animals and infected vectors when shipped by flights, containers or road transport is considered as other plausible pathways of introduction into Europe. The overall risk of introduction of RVF into EU through the movement of infected animals is very low in all the EU regions and in all MSs (less than one epidemic every 500 years), given the strict EU animal import policy. The same level of risk of introduction in all the EU regions was estimated also considering the movement of infected vectors, with the highest level for Belgium, Greece, Malta, the Netherlands (one epidemic every 228-700 years), mainly linked to the number of connections by air and sea transports with African RVF infected countries. Although the EU territory does not seem to be directly exposed to an imminent risk of RVFV introduction, the risk of further spread into countries neighbouring the EU and the risks of possible introduction of infected vectors, suggest that EU authorities need to strengthen their surveillance and response capacities, as well as the collaboration with North African and Middle Eastern countries.
Collapse
|
5
|
Terasaki K, Juelich TL, Smith JK, Kalveram B, Perez DD, Freiberg AN, Makino S. A single-cycle replicable Rift Valley fever phlebovirus vaccine carrying a mutated NSs confers full protection from lethal challenge in mice. Sci Rep 2018; 8:17097. [PMID: 30459418 PMCID: PMC6244155 DOI: 10.1038/s41598-018-35472-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/05/2018] [Indexed: 11/09/2022] Open
Abstract
Rift Valley fever phlebovirus (RVFV) is a pathogen of Rift Valley fever, which is a mosquito-borne zoonotic disease for domestic livestock and humans in African countries. Currently, no approved vaccine is available for use in non-endemic areas. The MP-12 strain is so far the best live attenuated RVFV vaccine candidate because of its good protective efficacy in animal models. However, there are safety concerns for use of MP-12 in humans. We previously developed a single-cycle replicable MP-12 (scMP-12) which lacks NSs gene and undergoes only a single round of viral replication because of its impaired ability to induce membrane-membrane fusion. In the present study, we generated an scMP-12 mutant (scMP-12-mutNSs) carrying a mutant NSs, which degrades double-stranded RNA-dependent protein kinase R but does not inhibit host transcription. Immunization of mice with a single dose (105 PFU) of scMP-12-mutNSs elicited RVFV neutralizing antibodies and high titers of anti-N IgG production and fully protected the mice from lethal wild-type RVFV challenge. Immunogenicity and protective efficacy of scMP-12-mutNSs were better than scMP-12, demonstrating that scMP-12-mutNSs is a more efficacious vaccine candidate than scMP-12. Furthermore, our data suggested that RVFV vaccine efficacy can be improved by using this specific NSs mutant.
Collapse
Affiliation(s)
- Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Terry L Juelich
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Jennifer K Smith
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Birte Kalveram
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - David D Perez
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Alexander N Freiberg
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.
| |
Collapse
|
6
|
Attenuation and protective efficacy of Rift Valley fever phlebovirus rMP12-GM50 strain. Vaccine 2017; 35:6634-6642. [PMID: 29061350 DOI: 10.1016/j.vaccine.2017.10.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 09/20/2017] [Accepted: 10/12/2017] [Indexed: 11/24/2022]
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa and the Arabian Peninsula that affects sheep, cattle, goats, camels, and humans. Effective vaccination of susceptible ruminants is important for the prevention of RVF outbreaks. Live-attenuated RVF vaccines are in general highly immunogenic in ruminants, whereas residual virulence might be a concern for vulnerable populations. It is also important for live-attenuated strains to encode unique genetic markers for the differentiation from wild-type RVFV strains. In this study, we aimed to strengthen the attenuation profile of the MP-12 vaccine strain via the introduction of 584 silent mutations. To minimize the impact on protective efficacy, codon usage and codon pair bias were not de-optimized. The resulting rMP12-GM50 strain showed 100% protective efficacy with a single intramuscular dose, raising a 1:853 mean titer of plaque reduction neutralization test. Moreover, outbred mice infected with one of three pathogenic reassortant ZH501 strains, which encoded rMP12-GM50 L-, M-, or S-segments, showed 90%, 50%, or 30% survival, respectively. These results indicate that attenuation of the rMP12-GM50 strain is significantly attenuated via the L-, M-, and S-segments. Recombinant RVFV vaccine strains encoding similar silent mutations will be also useful for the surveillance of reassortant strains derived from vaccine strains in endemic countries.
Collapse
|
7
|
Lokugamage N, Ikegami T. Genetic stability of Rift Valley fever virus MP-12 vaccine during serial passages in culture cells. NPJ Vaccines 2017; 2:20. [PMID: 29167748 PMCID: PMC5627234 DOI: 10.1038/s41541-017-0021-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 05/24/2017] [Accepted: 06/06/2017] [Indexed: 12/15/2022] Open
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa which affects both ruminants and humans. RVF causes serious damage to the livestock industry and is also a threat to public health. The Rift Valley fever virus has a segmented negative-stranded RNA genome consisting of Large (L)-, Medium (M)-, and Small (S)-segments. The live-attenuated MP-12 vaccine is immunogenic in livestock and humans, and is conditionally licensed for veterinary use in the U.S. The MP-12 strain encodes 23 mutations (nine amino acid substitutions) and is attenuated through a combination of mutations in the L-, M-, and S-segments. Among them, the M-U795C, M-A3564G, and L-G3104A mutations contribute to viral attenuation through the L- and M-segments. The M-U795C, M-A3564G, L-U533C, and L-G3750A mutations are also independently responsible for temperature-sensitive (ts) phenotype. We hypothesized that a serial passage of the MP-12 vaccine in culture cells causes reversions of the MP-12 genome. The MP-12 vaccine and recombinant rMP12-ΔNSs16/198 were serially passaged 25 times. Droplet digital PCR analysis revealed that the reversion occurred at L-G3750A during passages of MP-12 in Vero or MRC-5 cells. The reversion also occurred at M-A3564G and L-U533C of rMP12-ΔNSs16/198 in Vero cells. Reversion mutations were not found in MP-12 or the variant, rMP12-TOSNSs, in the brains of mice with encephalitis. This study characterized genetic stability of the MP-12 vaccine and the potential risk of reversion mutation at the L-G3750A ts mutation after excessive viral passages in culture cells.
Collapse
Affiliation(s)
- Nandadeva Lokugamage
- Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
- The Sealy Center for Vaccine Development, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
- The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
| |
Collapse
|
8
|
Ikegami T. Rift Valley fever vaccines: an overview of the safety and efficacy of the live-attenuated MP-12 vaccine candidate. Expert Rev Vaccines 2017; 16:601-611. [PMID: 28425834 DOI: 10.1080/14760584.2017.1321482] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Rift Valley fever (RVF) is a mosquito-borne zoonotic viral disease endemic to Africa and the Arabian Peninsula. High rates of abortion among infected ruminants and hemorrhagic fever in infected humans are major public health concerns. Commercially available veterinary RVF vaccines are important for preventing the spread of the Rift Valley fever virus (RVFV) in endemic countries; however, RVFV outbreaks continue to occur frequently in endemic countries in the 21st century. In the U.S., the live-attenuated MP-12 vaccine has been developed for both animal and human vaccination. This vaccine strain is well attenuated, and a single dose induces neutralizing antibodies in both ruminants and humans. Areas covered: This review describes scientific evidences of MP-12 vaccine efficacy and safety, as well as MP-12 variants recently developed by reverse genetics, in comparison with other RVF vaccines. Expert commentary: The containment of active RVF outbreaks and long-term protection from RVF exposure to infected mosquitoes are important goals for RVF vaccination. MP-12 vaccine will allow immediate vaccination of susceptible animals in case of an unexpected RVF outbreak in the U.S., whereas MP-12 vaccine may be also useful for the RVF control in endemic regions.
Collapse
Affiliation(s)
- Tetsuro Ikegami
- a Department of Pathology, Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infectious Diseases , The University of Texas Medical Branch , Galveston , TX , USA
| |
Collapse
|
9
|
Yamaoka S, Ebihara H. The two faces of Rift Valley fever virus virulence factor NSs: The development of a vaccine and the elucidation of pathogenesis. Virulence 2016; 7:856-859. [PMID: 27432532 DOI: 10.1080/21505594.2016.1213938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Satoko Yamaoka
- a Molecular Virology and Host-Pathogen Interaction Unit, Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton , MT , USA
| | - Hideki Ebihara
- a Molecular Virology and Host-Pathogen Interaction Unit, Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton , MT , USA
| |
Collapse
|
10
|
Nishiyama S, Slack OAL, Lokugamage N, Hill TE, Juelich TL, Zhang L, Smith JK, Perez D, Gong B, Freiberg AN, Ikegami T. Attenuation of pathogenic Rift Valley fever virus strain through the chimeric S-segment encoding sandfly fever phlebovirus NSs or a dominant-negative PKR. Virulence 2016; 7:871-881. [PMID: 27248570 DOI: 10.1080/21505594.2016.1195528] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Rift Valley fever is a mosquito-borne zoonotic disease affecting ruminants and humans. Rift Valley fever virus (RVFV: family Bunyaviridae, genus Phlebovirus) causes abortions and fetal malformations in ruminants, and hemorrhagic fever, encephalitis, or retinitis in humans. The live-attenuated MP-12 vaccine is conditionally licensed for veterinary use in the US. However, this vaccine lacks a marker for the differentiation of vaccinated from infected animals (DIVA). NSs gene is dispensable for RVFV replication, and thus, rMP-12 strains lacking NSs gene is applicable to monitor vaccinated animals. However, the immunogenicity of MP-12 lacking NSs was not as high as parental MP-12. Thus, chimeric MP-12 strains encoding NSs from either Toscana virus (TOSV), sandfly fever Sicilian virus (SFSV) or Punta Toro virus Adames strain (PTA) were characterized previously. Although chimeric MP-12 strains are highly immunogenic, the attenuation through the S-segment remains unknown. Using pathogenic ZH501 strain, we aimed to demonstrate the attenuation of ZH501 strain through chimeric S-segment encoding either the NSs of TOSV, SFSV, PTA, or Punta Toro virus Balliet strain (PTB). In addition, we characterized rZH501 encoding a human dominant-negative PKR (PKRΔE7), which also enhances the immunogenicity of MP-12. Study done on mice revealed that attenuation of rZH501 occurred through the S-segment encoding either PKRΔE7 or SFSV NSs. However, rZH501 encoding either TOSV, PTA, or PTB NSs in the S-segment uniformly caused lethal encephalitis. Our results indicated that the S-segments encoding PKRΔE7 or SFSV NSs are attenuated and thus applicable toward next generation MP-12 vaccine candidates that encode a DIVA marker.
Collapse
Affiliation(s)
- Shoko Nishiyama
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Olga A L Slack
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Nandadeva Lokugamage
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Terence E Hill
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Terry L Juelich
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Lihong Zhang
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Jennifer K Smith
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - David Perez
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Bin Gong
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,c The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Alexander N Freiberg
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,c The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,d The Sealy Center for Vaccine Development, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Tetsuro Ikegami
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,c The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,d The Sealy Center for Vaccine Development, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| |
Collapse
|
11
|
Léger P, Lozach PY. Bunyaviruses: from transmission by arthropods to virus entry into the mammalian host first-target cells. Future Virol 2015. [DOI: 10.2217/fvl.15.52] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The Bunyaviridae constitute a large family of animal RNA viruses distributed worldwide, most members of which are transmitted to vertebrate hosts by arthropods and can cause severe pathologies in humans and livestock. With an increasing number of outbreaks, arthropod-borne bunyaviruses (arbo-bunyaviruses) present a global threat to public health and agricultural productivity. Yet transmission, tropism, receptors and cell entry remain poorly characterized. The focus of this review is on the initial infection of mammalian hosts by arbo-bunyaviruses from cellular and molecular perspectives, with particular attention to the human host. We address current knowledge and advances regarding the identity of the first-target cells and the subsequent processes of entry and penetration into the cytosol. Aspects of the vector-to-host switch that influence the early steps of cell infection in mammalian skin, where incoming particles are introduced by infected arthropods, are also highlighted and discussed.
Collapse
Affiliation(s)
- Psylvia Léger
- CellNetworks – Cluster of Excellence & Department of Infectious Diseases, Virology, University Hospital Heidelberg, D-69120 Heidelberg, Germany
| | - Pierre-Yves Lozach
- CellNetworks – Cluster of Excellence & Department of Infectious Diseases, Virology, University Hospital Heidelberg, D-69120 Heidelberg, Germany
| |
Collapse
|
12
|
Gowen BB, Westover JB, Sefing EJ, Bailey KW, Nishiyama S, Wandersee L, Scharton D, Jung KH, Ikegami T. MP-12 virus containing the clone 13 deletion in the NSs gene prevents lethal disease when administered after Rift Valley fever virus infection in hamsters. Front Microbiol 2015; 6:651. [PMID: 26175722 PMCID: PMC4484224 DOI: 10.3389/fmicb.2015.00651] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 06/15/2015] [Indexed: 12/02/2022] Open
Abstract
Rift Valley fever virus (RVFV; Bunyaviridae, Phlebovirus) causes a range of illnesses that include retinitis, fulminant hepatitis, neurologic disease, and hemorrhagic fever. In hospitalized individuals, case fatality rates can be as high as 10–20%. There are no vaccines or antivirals approved for human use to prevent or treat severe RVFV infections. We previously tested the efficacy of the MP-12 vaccine strain and related variants with NSs truncations as a post-exposure prophylaxis in mice infected with wild-type pathogenic RVFV strain ZH501. Post-exposure efficacy of the rMP12-C13type, a recombinant MP-12 vaccine virus which encodes an in-frame truncation removing 69% of the NSs protein, resulted in 30% survival when administering the virus within 30 min of subcutaneous ZH501 challenge in mice, while the parental MP-12 virus conferred no protection by post-exposure vaccination. Here, we demonstrate uniform protection of hamsters by post-exposure vaccination with rMP12-C13type administered 6 h post-ZH501 infection while no efficacy was observed with the parental MP-12 virus. Notably, both the MP-12 and rMP12-C13type viruses were highly effective (100% protection) when administered 21 days prior to challenge. In a subsequent study delaying vaccination until 8, 12, and 24 h post-RVFV exposure, we observed 80, 70, and 30% survival, respectively. Our findings indicate that the rapid protective innate immune response elicited by rMP12-C13type may be due to the truncated NSs protein, suggesting that the resulting functional inactivation of NSs plays an important role in the observed post-exposure efficacy. Taken together, the data demonstrate that post-exposure vaccination with rMP12-C13type is effective in limiting ZH501 replication and associated disease in standard pre-exposure vaccination and post-challenge treatment models of RVFV infection, and suggest an extended post-exposure prophylaxis window beyond that initially observed in mice.
Collapse
Affiliation(s)
- Brian B Gowen
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, UT, USA ; Institute for Antiviral Research, Utah State University , Logan, UT, USA ; School of Veterinary Medicine, Utah State University , Logan, UT, USA
| | - Jonna B Westover
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, UT, USA ; Institute for Antiviral Research, Utah State University , Logan, UT, USA
| | - Eric J Sefing
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, UT, USA ; Institute for Antiviral Research, Utah State University , Logan, UT, USA
| | - Kevin W Bailey
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, UT, USA ; Institute for Antiviral Research, Utah State University , Logan, UT, USA
| | - Shoko Nishiyama
- Department of Pathology, The University of Texas Medical Branch , Galveston, TX, USA
| | - Luci Wandersee
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, UT, USA ; Institute for Antiviral Research, Utah State University , Logan, UT, USA
| | - Dionna Scharton
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, UT, USA ; Institute for Antiviral Research, Utah State University , Logan, UT, USA
| | - Kie-Hoon Jung
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, UT, USA ; Institute for Antiviral Research, Utah State University , Logan, UT, USA
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch , Galveston, TX, USA ; Sealy Center for Vaccine Development, The University of Texas Medical Branch , Galveston, TX, USA ; Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch , Galveston, TX, USA
| |
Collapse
|
13
|
Terasaki K, Tercero BR, Makino S. Single-cycle replicable Rift Valley fever virus mutants as safe vaccine candidates. Virus Res 2015; 216:55-65. [PMID: 26022573 DOI: 10.1016/j.virusres.2015.05.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 05/05/2015] [Accepted: 05/06/2015] [Indexed: 10/23/2022]
Abstract
Rift Valley fever virus (RVFV) is an arbovirus circulating between ruminants and mosquitoes to maintain its enzootic cycle. Humans are infected with RVFV through mosquito bites or direct contact with materials of infected animals. The virus causes Rift Valley fever (RVF), which was first recognized in the Great Rift Valley of Kenya in 1931. RVF is characterized by a febrile illness resulting in a high rate of abortions in ruminants and an acute febrile illness, followed by fatal hemorrhagic fever and encephalitis in humans. Initially, the virus was restricted to the eastern region of Africa, but the disease has now spread to southern and western Africa, as well as outside of the African continent, e.g., Madagascar, Saudi Arabia and Yemen. There is a serious concern that the virus may spread to other areas, such as North America and Europe. As vaccination is an effective tool to control RVFV epidemics, formalin-inactivated vaccines and live-attenuated RVFV vaccines have been used in endemic areas. The formalin-inactivated vaccines require boosters for effective protection, whereas the live-attenuated vaccines enable the induction of protective immunity by a single vaccination. However, the use of live-attenuated RVFV vaccines for large human populations having a varied health status is of concern, because of these vaccines' residual neuro-invasiveness and neurovirulence. Recently, novel vaccine candidates have been developed using replication-defective RVFV that can undergo only a single round of replication in infected cells. The single-cycle replicable RVFV does not cause systemic infection in immunized hosts, but enables the conferring of protective immunity. This review summarizes the properties of various RVFV vaccines and recent progress on the development of the single-cycle replicable RVFV vaccines.
Collapse
Affiliation(s)
- Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555-1019, USA.
| | - Breanna R Tercero
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555-1019, USA
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555-1019, USA; Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, TX 77555-1019, USA; UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, TX 77555-1019, USA; Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, TX 77555-1019, USA; Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, TX 77555-1019, USA
| |
Collapse
|
14
|
Murakami S, Terasaki K, Ramirez SI, Morrill JC, Makino S. Development of a novel, single-cycle replicable rift valley Fever vaccine. PLoS Negl Trop Dis 2014; 8:e2746. [PMID: 24651859 PMCID: PMC3961198 DOI: 10.1371/journal.pntd.0002746] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 01/30/2014] [Indexed: 12/25/2022] Open
Abstract
Rift Valley fever virus (RVFV) (genus Phlebovirus, family Bunyaviridae) is an arbovirus that causes severe disease in humans and livestock in sub-Saharan African countries. Although the MP-12 strain of RVFV is a live attenuated vaccine candidate, neuroinvasiveness and neurovirulence of MP-12 in mice may be a concern when vaccinating certain individuals, especially those that are immunocompromised. We have developed a novel, single-cycle replicable MP-12 (scMP-12), which carries an L RNA, M RNA mutant encoding a mutant envelope protein lacking an endoplasmic reticulum retrieval signal and defective for membrane fusion function, and S RNA encoding N protein and green fluorescent protein. The scMP-12 underwent efficient amplification, then formed plaques and retained the introduced mutation after serial passages in a cell line stably expressing viral envelope proteins. However, inoculation of the scMP-12 into naïve cells resulted in a single round of viral replication, and production of low levels of noninfectious virus-like particles. Intracranial inoculation of scMP-12 into suckling mice did not cause clinical signs or death, a finding which demonstrated that the scMP-12 lacked neurovirulence. Mice immunized with a single dose of scMP-12 produced neutralizing antibodies, whose titers were higher than in mice immunized with replicon particles carrying L RNA and S RNA encoding N protein and green fluorescent protein. Moreover, 90% of the scMP-12-immunized mice were protected from wild-type RVFV challenge by efficiently suppressing viremia and replication of the challenge virus in the liver and the spleen. These data demonstrated that scMP-12 is a safe and immunogenic RVFV vaccine candidate.
Collapse
MESH Headings
- Animals
- Antibodies, Neutralizing/blood
- Antibodies, Viral/blood
- Disease Models, Animal
- Female
- Mice
- Mutant Proteins/genetics
- Mutant Proteins/metabolism
- Rift Valley Fever/prevention & control
- Rift Valley fever virus/genetics
- Rift Valley fever virus/immunology
- Rift Valley fever virus/physiology
- Survival Analysis
- Vaccines, Attenuated/administration & dosage
- Vaccines, Attenuated/adverse effects
- Vaccines, Attenuated/genetics
- Vaccines, Attenuated/immunology
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/adverse effects
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Viral Proteins/genetics
- Viral Proteins/immunology
- Viral Vaccines/administration & dosage
- Viral Vaccines/adverse effects
- Viral Vaccines/genetics
- Viral Vaccines/immunology
- Virus Internalization
- Virus Replication
Collapse
Affiliation(s)
- Shin Murakami
- Department of Microbiology and Immunology, the University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Kaori Terasaki
- Department of Microbiology and Immunology, the University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Sydney I. Ramirez
- Department of Pathology, the University of Texas Medical Branch, Galveston, Texas, United States of America
| | - John C. Morrill
- Department of Microbiology and Immunology, the University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Shinji Makino
- Department of Microbiology and Immunology, the University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Biodefense and Emerging Infectious Diseases, the University of Texas Medical Branch, Galveston, Texas, United States of America
- UTMB Center for Tropical Diseases, the University of Texas Medical Branch, Galveston, Texas, United States of America
- Sealy Center for Vaccine Development, the University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail:
| |
Collapse
|
15
|
Lihoradova O, Ikegami T. Countermeasure development for Rift Valley fever: deletion, modification or targeting of major virulence factor NSs.. Future Virol 2014; 9:27-39. [PMID: 24910709 DOI: 10.2217/fvl.13.117] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic disease characterized by a high rate of abortion in ruminants, and febrile illness, hemorrhagic fever, retinitis and encephalitis in humans. RVF is caused by the RVF virus (RVFV), belonging to the genus Phlebovirus of the family Bunyaviridae. RVFV encodes a major virulence factor, NSs, which is dispensable for viral replication, yet required for evasion of host innate immune responses. RVFV NSs inhibits host gene upregulation at the transcriptional level, while promoting viral translation in the cytoplasm. In this article, we summarize the virology and pathology of RVF, and countermeasure development for RVF, with emphasis on NSs function and applications.
Collapse
Affiliation(s)
- Olga Lihoradova
- Department of Pathology, University of Texas Medical Branch, MMNP3.206D, 301 University Blvd. Galveston, TX 77555-0436, USA
| | - Tetsuro Ikegami
- Department of Pathology, University of Texas Medical Branch, MMNP3.206D, 301 University Blvd. Galveston, TX 77555-0436, USA ; Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, TX, USA ; Center for Biodefense & Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, TX, USA
| |
Collapse
|
16
|
Lihoradova O, Ikegami T. Modifying the NSs gene to improve live-attenuated vaccine for Rift Valley fever. Expert Rev Vaccines 2013; 11:1283-5. [PMID: 23249225 DOI: 10.1586/erv.12.106] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
17
|
Lihoradova OA, Indran SV, Kalveram B, Lokugamage N, Head JA, Gong B, Tigabu B, Juelich TL, Freiberg AN, Ikegami T. Characterization of Rift Valley fever virus MP-12 strain encoding NSs of Punta Toro virus or sandfly fever Sicilian virus. PLoS Negl Trop Dis 2013; 7:e2181. [PMID: 23638202 PMCID: PMC3630143 DOI: 10.1371/journal.pntd.0002181] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 03/15/2013] [Indexed: 12/22/2022] Open
Abstract
Rift Valley fever virus (RVFV; genus Phlebovirus, family Bunyaviridae) is a mosquito-borne zoonotic pathogen which can cause hemorrhagic fever, neurological disorders or blindness in humans, and a high rate of abortion in ruminants. MP-12 strain, a live-attenuated candidate vaccine, is attenuated in the M- and L-segments, but the S-segment retains the virulent phenotype. MP-12 was manufactured as an Investigational New Drug vaccine by using MRC-5 cells and encodes a functional NSs gene, the major virulence factor of RVFV which 1) induces a shutoff of the host transcription, 2) inhibits interferon (IFN)-β promoter activation, and 3) promotes the degradation of dsRNA-dependent protein kinase (PKR). MP-12 lacks a marker for differentiation of infected from vaccinated animals (DIVA). Although MP-12 lacking NSs works for DIVA, it does not replicate efficiently in type-I IFN-competent MRC-5 cells, while the use of type-I IFN-incompetent cells may negatively affect its genetic stability. To generate modified MP-12 vaccine candidates encoding a DIVA marker, while still replicating efficiently in MRC-5 cells, we generated recombinant MP-12 encoding Punta Toro virus Adames strain NSs (rMP12-PTNSs) or Sandfly fever Sicilian virus NSs (rMP12-SFSNSs) in place of MP-12 NSs. We have demonstrated that those recombinant MP-12 viruses inhibit IFN-β mRNA synthesis, yet do not promote the degradation of PKR. The rMP12-PTNSs, but not rMP12-SFSNSs, replicated more efficiently than recombinant MP-12 lacking NSs in MRC-5 cells. Mice vaccinated with rMP12-PTNSs or rMP12-SFSNSs induced neutralizing antibodies at a level equivalent to those vaccinated with MP-12, and were efficiently protected from wild-type RVFV challenge. The rMP12-PTNSs and rMP12-SFSNSs did not induce antibodies cross-reactive to anti-RVFV NSs antibody and are therefore applicable to DIVA. Thus, rMP12-PTNSs is highly efficacious, replicates efficiently in MRC-5 cells, and encodes a DIVA marker, all of which are important for vaccine development for Rift Valley fever. Upon outbreak of zoonotic viral diseases in herds of animals, early detection of naturally infected animals and prevention of further viral spread are important for minimizing the impact of outbreak in the society. Vaccination may compromise the identification of infected animals since both natural infection and vaccination induce antibodies specific to the pathogen. Therefore, new generation vaccines should have a marker to differentiate infected from vaccinated animals (DIVA). Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic pathogen which can cause hemorrhagic fever, neurological disorders or blindness in humans and a high-rate abortion in ruminants. MP-12 strain, a live-attenuated candidate vaccine, is safe and immunogenic, but lacks a DIVA marker. In this study, we developed and characterized improved MP-12 viruses which encode a DIVA marker by replacing the virulence gene with that of serologically distinct viruses belonging to the same genera. The novel MP-12 variant with such DIVA marker was highly efficacious and replicated efficiently in human diploid cells for vaccine production, and will become alternative candidate vaccines of MP-12 for veterinary applications.
Collapse
Affiliation(s)
- Olga A. Lihoradova
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Sabarish V. Indran
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Birte Kalveram
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Nandadeva Lokugamage
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jennifer A. Head
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Bin Gong
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Bersabeh Tigabu
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Terry L. Juelich
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Alexander N. Freiberg
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Galveston National Laboratory, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail:
| |
Collapse
|
18
|
Gowen BB, Bailey KW, Scharton D, Vest Z, Westover JB, Skirpstunas R, Ikegami T. Post-exposure vaccination with MP-12 lacking NSs protects mice against lethal Rift Valley fever virus challenge. Antiviral Res 2013; 98:135-43. [PMID: 23523764 DOI: 10.1016/j.antiviral.2013.03.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/19/2013] [Accepted: 03/01/2013] [Indexed: 11/17/2022]
Abstract
Rift Valley fever virus (RVFV) causes severe disease in humans and livestock. There are currently no approved antivirals or vaccines for the treatment or prevention of RVF disease in humans. A major virulence factor of RVFV is the NSs protein, which inhibits host transcription including the interferon (IFN)-β gene and promotes the degradation of dsRNA-dependent protein kinase, PKR. We analyzed the efficacy of the live-attenuated MP-12 vaccine strain and MP-12 variants that lack the NSs protein as post-exposure vaccinations. Although parental MP-12 failed to elicit a protective effect in mice challenged with wild-type (wt) RVFV by the intranasal route, significant protection was demonstrated by vaccination with MP-12 strains lacking NSs when they were administered at 20-30 min post-exposure. Viremia and virus replication in liver, spleen and brain were also inhibited by post-exposure vaccination with MP-12 lacking NSs. The protective effect was mostly lost when vaccination was delayed 6 or 24 h after intranasal RVFV challenge. When mice were challenged subcutaneously, efficacy of MP-12 lacking NSs was diminished, most likely due to more rapid dissemination of wt RVFV. Our findings suggest that post-exposure vaccination with MP-12 lacking NSs may be developed as a novel post-exposure treatment to prevent RVF.
Collapse
Affiliation(s)
- Brian B Gowen
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan, UT, USA.
| | | | | | | | | | | | | |
Collapse
|
19
|
Indran SV, Lihoradova OA, Phoenix I, Lokugamage N, Kalveram B, Head JA, Tigabu B, Smith JK, Zhang L, Juelich TL, Gong B, Freiberg AN, Ikegami T. Rift Valley fever virus MP-12 vaccine encoding Toscana virus NSs retains neuroinvasiveness in mice. J Gen Virol 2013; 94:1441-1450. [PMID: 23515022 DOI: 10.1099/vir.0.051250-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Rift Valley fever is a mosquito-borne zoonotic disease endemic to sub-Saharan Africa. Rift Valley fever virus (RVFV; genus Phlebovirus, family Bunyaviridae) causes high rates of abortion and fetal malformation in pregnant ruminants, and haemorrhagic fever, neurological disorders or blindness in humans. The MP-12 strain is a highly efficacious and safe live-attenuated vaccine candidate for both humans and ruminants. However, MP-12 lacks a marker to differentiate infected from vaccinated animals. In this study, we originally aimed to characterize the efficacy of a recombinant RVFV MP-12 strain encoding Toscana virus (TOSV) NSs gene in place of MP-12 NSs (rMP12-TOSNSs). TOSV NSs promotes the degradation of dsRNA-dependent protein kinase (PKR) and inhibits interferon-β gene up-regulation without suppressing host general transcription. Unexpectedly, rMP12-TOSNSs increased death in vaccinated outbred mice and inbred BALB/c or C57BL/6 mice. Immunohistochemistry showed diffusely positive viral antigens in the thalamus, hypothalamus and brainstem, including the medulla. No viral antigens were detected in spleen or liver, which is similar to the antigen distribution of moribund mice infected with MP-12. These results suggest that rMP12-TOSNSs retains neuroinvasiveness in mice. Our findings demonstrate that rMP12-TOSNSs causes neuroinvasion without any hepatic disease and will be useful for studying the neuroinvasion mechanism of RVFV and TOSV.
Collapse
Affiliation(s)
- Sabarish V Indran
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Olga A Lihoradova
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Inaia Phoenix
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Nandadeva Lokugamage
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Birte Kalveram
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jennifer A Head
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Bersabeh Tigabu
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jennifer K Smith
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Lihong Zhang
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Terry L Juelich
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Bin Gong
- Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Alexander N Freiberg
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, Texas, USA.,Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, Texas, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA.,Galveston National Laboratory, University of Texas Medical Branch, Galveston, Texas, USA
| | - Tetsuro Ikegami
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, Texas, USA.,Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, Texas, USA.,Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| |
Collapse
|
20
|
García-Sastre A, Mena I. Novel vaccine strategies against emerging viruses. Curr Opin Virol 2013; 3:210-6. [PMID: 23477832 PMCID: PMC3644304 DOI: 10.1016/j.coviro.2013.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 02/04/2013] [Indexed: 11/04/2022]
Abstract
One of the main public health concerns of emerging viruses is their potential introduction into and sustained circulation among populations of immunologically naïve, susceptible hosts. The induction of protective immunity through vaccination can be a powerful tool to prevent this concern by conferring protection to the population at risk. Conventional approaches to develop vaccines against emerging pathogens have significant limitations: lack of experimental tools for several emerging viruses of concern, poor immunogenicity, safety issues, or lack of cross-protection against antigenic variants. The unpredictability of the emergence of future virus threats demands the capability to rapidly develop safe, effective vaccines. We describe some recent advances in new vaccine strategies that are being explored as alternatives to classical attenuated and inactivated vaccines, and provide examples of potential novel vaccines for emerging viruses. These approaches might be applied to the control of many other emerging pathogens.
Collapse
Affiliation(s)
- Adolfo García-Sastre
- Department of Microbiology, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, United States.
| | | |
Collapse
|
21
|
Indran SV, Ikegami T. Novel approaches to develop Rift Valley fever vaccines. Front Cell Infect Microbiol 2012; 2:131. [PMID: 23112960 PMCID: PMC3481114 DOI: 10.3389/fcimb.2012.00131] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 10/05/2012] [Indexed: 01/26/2023] Open
Abstract
Rift Valley fever (RVF) is endemic to sub-Saharan Africa, and has spread into Madagascar, Egypt, Saudi Arabia, and Yemen. Rift Valley fever virus (RVFV) of the family Bunyaviridae, genus Phlebovirus causes hemorrhagic fever, neurological disorders or blindness in humans, and high rate abortion and fetal malformation in ruminants. RVFV is classified as a Category A Priority pathogen and overlap select agent by CDC/USDA due to its potential impact on public health and agriculture. There is a gap in the safety and immunogenicity in traditional RVF vaccines; the formalin-inactivated RVFV vaccine TSI-GSD-200 requires three doses for protection, and the live-attenuated Smithburn vaccine has a risk to cause abortion and fetal malformation in pregnant ruminants. In this review, problems of traditional vaccines and the safety and efficacy of recently reported novel RVF candidate vaccines including subunit vaccines, virus vector, and replicons are discussed.
Collapse
Affiliation(s)
- Sabarish V Indran
- Department of Pathology, The University of Texas Medical Branch Galveston, TX, USA
| | | |
Collapse
|
22
|
Rift Valley fever virus NSs inhibits host transcription independently of the degradation of dsRNA-dependent protein kinase PKR. Virology 2012; 435:415-24. [PMID: 23063407 DOI: 10.1016/j.virol.2012.09.031] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 08/14/2012] [Accepted: 09/26/2012] [Indexed: 01/25/2023]
Abstract
Rift Valley fever virus (RVFV) encodes one major virulence factor, the NSs protein. NSs suppresses host general transcription, including interferon (IFN)-β mRNA synthesis, and promotes degradation of the dsRNA-dependent protein kinase (PKR). We generated a novel RVFV mutant (rMP12-NSsR173A) specifically lacking the function to promote PKR degradation. rMP12-NSsR173A infection induces early phosphorylation of eIF2α through PKR activation, while retaining the function to inhibit host general transcription including IFN-β gene inhibition. MP-12 NSs but not R173A NSs binds to wt PKR. R173A NSs formed filamentous structure in nucleus in a mosaic pattern, which was distinct from MP-12 NSs filament pattern. Due to early phosphorylation of eIF2α, rMP12-NSsR173A could not efficiently accumulate viral proteins. Our results suggest that NSs-mediated host general transcription suppression occurs independently of PKR degradation, while the PKR degradation is important to inhibit the phosphorylation of eIF2α in infected cells undergoing host general transcription suppression.
Collapse
|