Результаты поиска

N-Glycans on the Rift Valley Fever Virus Envelope Glycoproteins Gn and Gc Redundantly Support Viral Infection via DC-SIGN.

Rift Valley fever is a mosquito-transmitted, zoonotic disease that infects humans and ruminants. Dendritic cell specific intercellular adhesion molecule 3 (ICAM-3) grabbing non-integrin (DC-SIGN) acts as a receptor for members of the phlebovirus genus. The Rift Valley fever virus (RVFV) glycoproteins (Gn/Gc) encode five putative N-glycan sequons (asparagine (N)-any amino acid (X)-serine (S)/threonine (T)) at positions: N438 (Gn), and N794, N829, N1035, and N1077 (Gc). The N-glycosylation profile and significance in viral infection via DC-SIGN have not been elucidated. Gc N-glycosylation was fi…

A Genome-Wide RNA Interference Screen Identifies a Role for Wnt/β-Catenin Signaling during Rift Valley Fever Virus Infection.

UNLABELLED: Rift Valley fever virus (RVFV) is an arbovirus within the Bunyaviridae family capable of causing serious morbidity and mortality in humans and livestock. To identify host factors involved in bunyavirus replication, we employed genome-wide RNA interference (RNAi) screening and identified 381 genes whose knockdown reduced infection. The Wnt pathway was the most represented pathway when gene hits were functionally clustered. With further investigation, we found that RVFV infection activated Wnt signaling, was enhanced when Wnt signaling was preactivated, was reduced with knockdown of …

Differences in aerosolization of Rift Valley fever virus resulting from choice of inhalation exposure chamber: implications for animal challenge studies.

The aerosol characteristics of Rift Valley fever virus (RVFV) were evaluated to achieve reproducible infection of experimental animals with aerosolized RVFV suitable for animal efficacy studies. Spray factor (SF), the ratio between the concentrations of the aerosolized agent to the agent in the aerosol generator, is used to compare performance differences between aerosol exposures. SF indicates the efficiency of the aerosolization process; a higher SF means a lower nebulizer concentration is needed to achieve a desired inhaled dose. Relative humidity levels as well as the duration of the expos…

Application of polar-orbiting, meteorological satellite data to detect flooding of Rift Valley Fever virus vector mosquito habitats in Kenya.

Measurements of green-leaf vegetation dynamics recorded by the advanced very high resolution radiometer instruments onboard National Oceanic and Atmospheric Administration satellites 7 and 9 were used to derive ground moisture and rainfall patterns in Kenya and monitor resultant flooding of mosquito larval habitats (dambos) likely to support Rift Valley Fever virus vector mosquitoes (Aedes and Culex spp.). Satellite-derived data from mid-1981 to December 1988 have been analysed with corresponding rainfall, flooding and vector population data as they relate to Rift Valley Fever virus ecology. S…

Rift Valley Fever Virus, Japanese Encephalitis Virus, and African Swine Fever Virus: Three Transboundary, Vector-Borne, Veterinary Biothreats With Diverse Surveillance, and Response Capacity Needs.

Early detection of emerging foreign animal diseases is critical to pathogen surveillance and control programs. Rift valley fever virus (RVFV), Japanese encephalitis virus (JEV), and African swine fever virus (ASFV) represent three taxonomically and ecologically diverse vector-borne viruses with the potential to be introduced to the United States. To promote preparedness for such an event, we reviewed the current surveillance strategies and diagnostic tools in practice around the world for these emerging viruses, and summarized key points pertaining to the availability of existing guidelines an…

Sequences and coding strategies of the S RNAs of Toscana and Rift Valley fever viruses compared to those of Punta Toro, Sicilian Sandfly fever, and Uukuniemi viruses.

The sequences and coding strategies of the S RNAs of two viruses, Toscana (TOS) and the M12 derivative of Rift Valley fever ZH-548 (RVF, Phlebovirus genus, Bunyaviridae) have been determined from cDNA clones and compared to the previously published sequences of Punta Toro (PT), Sandfly fever Sicilian (SFS), and Uukuniemi (UUK) viruses. All five viruses exhibit an ambisense coding strategy for their small (S) RNA species, i.e., one gene product (the NSs protein) is encoded in the 5' half of the viral RNA, a second (the N protein) is encoded in the sequence complementary to the 3' half. The term…

Serological evidence of hidden circulation of three arthropod-borne diseases (Rift Valley fever, West Nile fever, and Crimean-Congo haemorrhagic fever) in dromedary camels from the Eastern Algerian Sahara.

Several arthropod vectors, including ticks, sand flies, and mosquitoes, play a prominent role in the introduction and spread of numerous vir … ies between May and November 2023 were tested for IgG antibodies against the mosquito-borne viruses Rift Valley fever virus (RVFV) and West Nile virus (WNV), as well as the tick-borne Crimean-Congo haemorrhagic fever virus (CCHFV), using commercial ELISA kits. A total of 224, 79, and 73 serum samples were tested for RVFV, WNV, and CCHFV, respectively. The seropreva …

Meeting report: CEPI workshop on Rift Valley fever epidemiology and modeling to inform human vaccine development, Nairobi, 4-5 June 2024.

Rift Valley fever (RVF) is a zoonotic viral disease that causes epidemics and epizootics among humans and livestock, resulting in substantial health and socioeconomic consequences. Currently, there are no RVF vaccines licensed for humans, but several candidates show promise in early-stage development. Existing gaps in RVF epidemiological data and challenges associated with predicting RVF outbreak risk complicate the planning of efficacy studies, making the pathway to licensure for promising candidates unclear. In June 2024, the Coalition for Epidemic Preparedness Innovations (CEPI) convened a …

ZnNPs and senps co-adjuvants deliver superior and long-lasting protection: first report in inactivated Rift Valley fever vaccines for sheep.

Rift Valley Fever (RVF) poses a significant threat to livestock and human health, necessitating effective and safe vaccines. This study evaluated the immunogenicity and safety of novel inactivated RVF vaccines in sheep, enhanced with zinc oxide nanoparticles (ZnNPs) and selenium nanoparticles (SeNPs) as co-adjuvants, compared to an aluminum hydroxide gel (ALHV) adjuvanted vaccine alone. Our findings demonstrate that nanoparticle-formulated ALHV elicited a markedly faster onset of protection, achieving protective neutralizing antibody titers within 3–4 days post-vaccination, significantly accel…

Идентификация однократных аминокислотных изменений в Вирусном вирусе Рифт-Вэлли, политмеразы, которые вносят вклад в аттенуацию вируса в Виво.

Жар в долине Рифт (RVF) является зоонотической болезнью арбовируса, затрагивающей многие африканские страны и способной распространиться на другие географические районы. РВФ затрагивает овец, коз, скот и верблюдов, что приводит к большому числу абортов и гибели новорожденных ягнят. Кроме того, люди могут быть инфицированы, развивая обычно самоограничивающуюся болезнь, которая может превратиться в более серьезную болезнь в небольшом проценте случаев. Хотя в эндемических районах Африки имеются различные ветеринарные вакцины, на сегодняшний день не было выдано никаких лицензий на вакцину для чело

Совпадение в аннотации оригинала
Rift Valley fever (RVF) is an arboviral zoonotic disease affecting many African countries with the potential to spread to other geographical areas. RVF affects sheep, goats, cattle and camels, causing a high rate of abortions and death of newborn lambs. Also, humans can be infected, developing a usually self-limiting disease that can turn into a more severe …

An unusually long Rift valley fever inter-epizootic period in Zambia: Evidence for enzootic virus circulation and risk for disease outbreak.

Rift valley fever (RVF) is a mosquito-borne disease of animals and humans. Although RVF outbreaks are usually reported at 5-15-year intervals in sub-Saharan Africa, Zambia has experienced an unusually long inter-epizootic/-epidemic period of more than three decades. However, serological evidence of RVF virus (RVFV) infection in domestic ruminants during this period underscores the need for comprehensive investigation of the mechanisms of virus perpetuation and disease emergence. Mosquitoes (n = 16,778) captured from eight of the ten provinces of Zambia between April 2014 and May 2019 were pool…

Evidence of co-exposure with Brucella spp, Coxiella burnetii, and Rift Valley fever virus among various species of wildlife in Kenya.

BACKGROUND: Co-infection, especially with pathogens of dissimilar genetic makeup, may result in a more devastating impact on the host. Investigations on co-infection with neglected zoonotic pathogens in wildlife are necessary to inform appropriate prevention and control strategies to reduce disease burden in wildlife and the potential transmission of these pathogens between wildlife, livestock and humans. This study assessed co-exposure of various Kenyan wildflife species with Brucella spp, Coxiella burnetii and Rift Valley fever virus (RVFV). METHODOLOGY: A total of 363 sera from 16 differen…

Rift Valley Fever Virus Non-Structural Protein S Is Associated with Nuclear Translocation of Active Caspase-3 and Inclusion Body Formation.

Rift Valley fever phlebovirus (RVFV) causes Rift Valley fever (RVF), an emerging zoonotic disease that causes abortion storms and high mortality rates in young ruminants as well as severe or even lethal complications in a subset of human patients. This study investigates the pathomechanism of intranuclear inclusion body formation in severe RVF in a mouse model. Liver samples from immunocompetent mice infected with virulent RVFV 35/74, and immunodeficient knockout mice that lack interferon type I receptor expression and were infected with attenuated RVFV MP12 were compared to livers from uninfe…

Phylogenetic Analysis of Wesselsbron Virus Isolated from Field-Captured Mosquitoes during a Rift Valley Fever Outbreak in Kabale District, Uganda-2016.

After confirmation of two human cases of Rift Valley fever (RVF) in March 2016 in the Kabale district of Uganda, an entomological investigation was conducted with a focus on mosquito species composition and abundance of known and potential mosquito vector species, and virus testing to identify species most likely involved in Rift Valley fever virus transmission. This information could be used to forecast risk and facilitate improvement of prevention and response tools for use in preventing or controlling future outbreaks. From these collections, two virus isolates were obtained, one each from …

Quantitative Assessment of the Entry through Mechanical Transport in Aircraft of Rift Valley Fever Virus-Infected Mosquitoes into Previously Unaffected Areas.

(1): Rift Valley Fever (RVF) is a zoonotic disease of significant international health concern and considered as an emerging risk to Europe, where no RVF outbreaks in humans or animals have been reported so far. (2): Using a stochastic approach, we estimated the risk of RVF virus (RVFV) introduction during the period of May to October (the period when mosquito populations, including RVFV potential vectors, are present in European countries), into previously unaffected areas (e.g., United Kingdom, UK) via virus-carrying vectors traveling in commercial aircraft from RVF-affected countries (e.g.,…

Preliminary Evaluation of a Recombinant Rift Valley Fever Virus Glycoprotein Subunit Vaccine Providing Full Protection against Heterologous Virulent Challenge in Cattle.

Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic pathogen that causes periodic outbreaks of abortion in ruminant species and hemorrhagic disease in humans in sub-Saharan Africa. These outbreaks have a significant impact on veterinary and public health. Its introduction to the Arabian Peninsula in 2003 raised concerns of further spread of this transboundary pathogen to non-endemic areas. These concerns are supported by the presence of competent vectors in many non-endemic countries. There is no licensed RVF vaccine available for humans and only a conditionally licensed veterinary vac…

MVA Vectored Vaccines Encoding Rift Valley Fever Virus Glycoproteins Protect Mice against Lethal Challenge in the Absence of Neutralizing Antibody Responses.

In vitro neutralizing antibodies have been often correlated with protection against Rift Valley fever virus (RVFV) infection. We have reported previously that a single inoculation of sucrose-purified modified vaccinia Ankara (MVA) encoding RVFV glycoproteins (rMVAGnGc) was sufficient to induce a protective immune response in mice after a lethal RVFV challenge. Protection was related to the presence of glycoprotein specific CD8+ cells, with a low-level detection of in vitro neutralizing antibodies. In this work we extended those observations aimed to explore the role of humoral responses after …

Alteration in the Culex pipiens transcriptome reveals diverse mechanisms of the mosquito immune system implicated upon Rift Valley fever phlebovirus exposure.

Rift Valley fever phlebovirus (RVFV) causes an emerging zoonotic disease and is mainly transmitted by Culex and Aedes mosquitoes. While Aedes aegypti-dengue virus (DENV) is the most studied model, less is known about the genes involved in infection-responses in other mosquito-arboviruses pairing. The main objective was to investigate the molecular responses of Cx. pipiens to RVFV exposure focusing mainly on genes implicated in innate immune responses. Mosquitoes were fed with blood spiked with RVFV. The fully-engorged females were pooled at 3 different time points: 2 hours post-exposure (hpe),…

Safety and immunogenicity of a live attenuated Rift Valley Fever recombinant arMP-12ΔNSm21/384 vaccine candidate for sheep, goats and calves.

Rift Valley fever (RVF) causes serious health and economic losses to the livestock industry as well as a significant cause of human disease. The prevention of RVF in Africa is a global priority, however, available vaccines have only been partially effective. Therefore, the objective of this study was to evaluate the safety and immunogenicity of a live, attenuated recombinant RVFV arMP-12ΔNSm21/384 nucleotide deletion vaccine candidate in domestic ruminants. Evaluation involved testing to determine the infectivity titer of the vaccine virus in Vero cells for industrial scale up vaccine producti…

Host-feeding patterns of Aedes (Aedimorphus) vexans arabiensis, a Rift Valley Fever virus vector in the Ferlo pastoral ecosystem of Senegal.

BACKGROUND: Host-vector contact is a key factor in vectorial capacity assessment and thus the transmission of mosquito-borne viruses such as Rift Valley Fever (RVF), an emerging zoonotic disease of interest in West Africa. The knowledge of the host-feeding patterns of vector species constitutes a key element in the assessment of their epidemiological importance in a given environment. The aim of this work was to identify the blood meal origins of the mosquito Aedes vexans arabiensis, the main vector of RVF virus in the Ferlo pastoral ecosystem of Senegal. METHODOLOGY/PRINCIPAL FINDINGS: Engor…