Результаты поиска

Expression of cytokines following vaccination of goats with a recombinant capripoxvirus vaccine expressing Rift Valley fever virus proteins.

The mosquito-borne Rift Valley fever virus (RVFV) causes severe diseases in domesticated animals including cattle, sheep, camels and goats. Capripoxviruses (CPV) are suitable vectors for multivalent vaccine development. A recombinant rKS1-based CPV expressing the gene encoding the viral glycoprotein Gn of RVFV has been shown to induce protection in mice and sheep. The aim of this study was to evaluate the immunogenicity induced by this candidate vaccine in goats, and the level of cytokines produced by RVFV-specific Th1 and Th2 lymphocytes. The results of this study suggest that Th2 mediates im…

Short Interfering RNA Inhibits Rift Valley Fever Virus Replication and Degradation of Protein Kinase R in Human Cells.

Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic pathogen causing severe outbreaks in humans and livestock in sub-Saharan Africa and the Arabian Peninsula. Human infections are characterized by fever, sometimes leading to encephalitis, retinitis, hemorrhagic fever, and occasionally death. There are currently no fully licensed vaccines or effective therapies for human use. Gene silencing mediated by double-stranded short interfering RNA (siRNA) is a sequence-specific, highly conserved mechanism in eukaryotes, which serves as an antiviral defense mechanism. Here, we demonstrate that s…

Development of a Rift Valley fever real-time RT-PCR assay that can detect all three genome segments.

Outbreaks of Rift Valley fever in Kenya, Madagascar, Mauritania, and South Africa had devastating effects on livestock and human health. In addition, this disease is a food security issue for endemic countries. There is growing concern for the potential introduction of RVF into non-endemic countries. A number of single-gene target amplification assays have been developed for the rapid detection of RVF viral RNA. This paper describes the development of an improved amplification assay that includes two confirmatory target RNA segments (L and M) and a third target gene, NSs, which is deleted in t…

Nuclear relocalization of polyadenylate binding protein during rift valley fever virus infection involves expression of the NSs gene.

Rift Valley fever virus (RVFV), an ambisense member of the family Bunyaviridae, genus Phlebovirus, is the causative agent of Rift Valley fever, an important zoonotic infection in Africa and the Middle East. Phlebovirus proteins are translated from virally transcribed mRNAs that, like host mRNA, are capped but, unlike host mRNAs, are not polyadenylated. Here, we investigated the role of PABP1 during RVFV infection of HeLa cells. Immunofluorescence studies of infected cells demonstrated a gross relocalization of PABP1 to the nucleus late in infection. Immunofluorescence microscopy studies of nuc…

Prevalence of Rift Valley fever immunoglobulin G antibody in various occupational groups before the 2007 outbreak in Tanzania.

A cross-sectional sero survey of 199 apparently healthy persons from various occupations was carried out in Tanga, Tanzania in November 2004 to investigate exposure to Rift Valley fever (RVF) virus. Sera were tested for the presence of antibodies to RVF virus by the inhibition enzyme-linked immunosorbent assay (ELISA) for detecting immunoglobulin G (IgG). All reactive sera were further tested by the capture ELISA test and specific RVF immunoglobulin M (IgM) assay. Eight (4.0%) tested positive for IgG and none of the samples tested positive for IgM. Among the occupational groups examined, the s…

Характеристика иммунной реакции и защитной эффективности у мышей после иммунизации вирусом " Фера Рифт Вэлли " , построенным CDNA.

СВЯЗАННЫЕ С Скотом и людьми, " Жемчужина долины Рифт " считается одним из самых важных вирусных зоонозов в Африке. Однако никаких лицензированных вакцин или эффективных методов лечения для использования людьми пока не имеется. Интересным подходом являются вакцины от голой ДНК, поскольку вирус является весьма инфекционным, а существующие штаммы вакцины от лихорадки Рифт-Вэлли свидетельствуют о негативном воздействии при испытаниях на животных. В этом исследовании в мышах оценивалась иммунизация генного ружья с помощью CDNA, кодирующего структурные белки вируса лихорадки Рифт-Вэлли. Сп

Совпадение в аннотации оригинала
BACKGROUND: Affecting both livestock and humans, Rift Valley Fever is considered as one of the most important viral zoonoses in Africa. However, no licensed vaccines or effective treatments are yet available for human use. Naked DNA vaccines are an interesting approach since the virus is highly infectious and existing attenuated Rift Valley Fever virus vacci…

Electron cryo-microscopy and single-particle averaging of Rift Valley fever virus: evidence for GN-GC glycoprotein heterodimers.

Rift Valley fever virus (RVFV) is a member of the genus Phlebovirus within the family Bunyaviridae. It is a mosquito-borne zoonotic agent that can cause hemorrhagic fever in humans. The enveloped RVFV virions are known to be covered by capsomers of the glycoproteins G(N) and G(C), organized on a T=12 icosahedral lattice. However, the structural units forming the RVFV capsomers have not been determined. Conflicting biochemical results for another phlebovirus (Uukuniemi virus) have indicated the existence of either G(N) and G(C) homodimers or G(N)-G(C) heterodimers in virions. Here, we have stud…

A replication-incompetent Rift Valley fever vaccine: chimeric virus-like particles protect mice and rats against lethal challenge.

Virus-like particles (VLPs) present viral antigens in a native conformation and are effectively recognized by the immune system and therefore are considered as suitable and safe vaccine candidates against many viral diseases. Here we demonstrate that chimeric VLPs containing Rift Valley fever virus (RVFV) glycoproteins G(N) and G(C), nucleoprotein N and the gag protein of Moloney murine leukemia virus represent an effective vaccine candidate against Rift Valley fever, a deadly disease in humans and livestock. Long-lasting humoral and cellular immune responses are demonstrated in a mouse model …

Antigenic and genetic relationships among Rift Valley fever virus and other selected members of the genus Phlebovirus (Bunyaviridae).

Preliminary serologic data indicated that two South American phleboviruses (Belterra virus [BELTV] and Icoaraci virus [ICOV]) may be related to Rift Valley fever virus (RVFV), an African phlebovirus that causes severe hepatitis and hemorrhagic fever in humans. To further define this relationship and to investigate the underlying genetic basis, comparative serologic and genetic sequence analyses were performed with RVFV and five other New World phleboviruses (ICOV, BELTV, Salobo virus, Joa virus, and Frijoles virus). Serologically, a one-way cross reaction was confirmed between antibodies again…

Quantitative real-time PCR detection of Rift Valley fever virus and its application to evaluation of antiviral compounds.

The Rift Valley fever virus (RVFV), a member of the genus Phlebovirus (family Bunyaviridae) is an enveloped negative-strand RNA virus with a tripartite genome. Until 2000, RVFV circulation was limited to the African continent, but the recent deadly outbreak in the Arabian Peninsula dramatically illustrated the need for rapid diagnostic methods, effective treatments, and prophylaxis. A method for quantifying the small RNA segment by a real-time detection reverse transcription (RT)-PCR using TaqMan technology and targeting the nonstructural protein-coding region was developed, and primers and a …

Detection of human immunoglobulins G and M antibodies to Rift Valley fever virus by enzyme-linked immunosorbent assay.

Rift Valley fever virus (RVFV) is an important human and animal pathogen in Africa and has been responsible for infections in travelers. Because of the aerosol infectivity and risk of dissemination of the virus, a need exists for simple, safe, serological tests for diagnosis. An enzyme-linked immunosorbent assay (ELISA) was developed to detect RVFV-specific immunoglobulins (immunoglobulin G [IgG] and IgM). In the test, a betapropiolactone-inactivated, sucrose-acetone-extracted, suckling mouse liver RVFV antigen was captured by mouse RVFV antibodies adsorbed to polystyrene plates. The test samp…

A rift Valley fever vaccine trial. I. Side effects and serologic response over a six-month follow-up.

A formalin-inactivated Rift Valley fever vaccine, originally produced in primary monkey kidney cells, has been used to protect laboratory workers. A trial of a modified vaccine, newly formulated in well-characterized diploid fetal rhesus lung cells, was conducted with 114 men aged 19--24 years. Of the 107 subjects who received up to three injections of 0.1 to 1 ml vaccine (an additional seven received a placebo) one had a local hypersensitivity-type reaction and another a generalized urticarial syndrome. Both cases had a prior history of hypersensitivity states. No pyrogenicity was detected an…

[In vitro activity of Russian ribavirin on the models of Crimean-Congo hemorrhagic fever virus, Rift Valley fever virus, and Tahyna and Dhori viruses].

The high activity of ribavirin made by effective biotechnology in Russia was established in in vitro experiments using the models Crimean-Congo hemorrhagic fever virus, Rift Valley fever virus, and Tahyna and Dhori viruses, which suggests that it is promising in using the drug in the treatment of infection with these viruses.

Potent neutralization of Rift Valley fever virus mediated by monoclonal antibodies via concurrent inhibition of attachment and fusion.

Rift Valley fever virus (RVFV) is one of the most important mosquito-borne pathogens that causes substantial morbidity and mortality in livestock and humans. Despite its public health and economic impact, no licenced vaccines or therapeutics are currently available for human use. Here, we report the isolation of a panel of Gn-specific monoclonal antibodies (mAbs) from the memory B cells of rhesus macaques immunized with Ad4-GnGc or Ad5-GnGc. 20 mAbs with neutralizing activity were identified and divided into two groups, targeting subdomain I and subdomain III of the Gn protein, respectively. I…

Cross-border introduction risk of Rift Valley fever virus: surveillance evidence from intercepted livestock in southwestern Saudi Arabia.

INTRODUCTION: Rift Valley fever (RVF) is a mosquito-borne transboundary zoonotic disease with major implications for animal and public health. Following the 2000 outbreak in Saudi Arabia and Yemen, the risk of reintroduction through cross-border livestock movement remains a continuing concern. This study aimed to estimate the seroprevalence of Rift Valley fever virus (RVFV) among illegally introduced livestock intercepted in the Jazan region of southwestern Saudi Arabia and to assess the added value of combined serological and molecular testing for detecting recent infection under routine surv…

Have you heard of Rift Valley fever? Findings from a multi-country study in East and Central Africa.

INTRODUCTION: Rift Valley Fever (RVF) has caused several outbreaks across Africa, impacting human health and animal trade. Recent reports indicate sporadic detections of RVF virus among humans and animals in East Africa during inter-epidemic periods. We assessed RVF knowledge levels in East and Central Africa across countries with different epidemiological profiles. MATERIALS AND METHODS: Individuals aged ≥10 years with acute febrile illness were enrolled from six health facilities in Kenya, Uganda, and the Democratic Republic of Congo (DRC). Sociodemographic information was collected, and pa…

Evaluation of a Combined Live Attenuated Vaccine against Lumpy Skin Disease, Contagious Bovine Pleuropneumonia and Rift Valley Fever.

The use of effective vaccines is among the most important strategies for the prevention and progressive control of transboundary infectious … he prevention and control of Lumpy Skin Disease (LSD), Contagious Bovine Pleuropneumonia (CBPP) and Rift Valley fever (RVF). The LSD and CBPP were formulated as a combined vaccine, and the RVF was formulated separately as live attenuated vaccines. These consisted of a Mycoplasma MmmSC T1/44 strain that was propagated in Hayflick-modified medium, RVF virus vaccine, …

The Rift Valley fever (RVF) vaccine candidate 40Fp8 shows an extreme attenuation in IFNARKO mice following intranasal inoculation.

Rift Valley fever (RVF) is an important zoonotic viral disease affecting several species of domestic and wild ruminants, causing major economic losses and dozens of human deaths in various geographical areas of Africa, where it is endemic. Although it is not present in Europe, there is a risk of its introduction and spread linked to globalisation and climate change. At present, the only measure that could help to prevent the disease is vaccination of flocks in areas at risk of RVF. Available live attenuated vaccines are an effective means of controlling the disease, but their use is often ques…

A Review of Nonhuman Primate Models of Rift Valley Fever Virus Infection: Progress, Challenge Strains, and Future Directions.

Rift Valley fever (RVF) is a mosquito-borne viral disease that primarily affects animals, especially ruminants, but has the capacity to infect humans and result in outbreaks. Infection with the causative agent, RVF virus (RVFV), causes severe disease in domestic animals, especially sheep, resulting in fever, anorexia, immobility, abortion, and high morbidity and mortality rates in neonate animals. Humans become infected through exposure to infected animals and, less frequently, directly via a mosquito bite. A greater awareness of RVFV and its epidemic potential has resulted in increased invest…