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Order Amarillovirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
The replicons derived from Kunjin virus (KUNV), a close relative of WNV and a member of the West Nile virus species, represent the most extensively characterized system of the subviral replicon subject, due to the pioneering efforts of Alexander A. Khromykh’s team. The KUNV replicon system has been used successfully both to study flavivirus replication and to develop a promising new tool for heterologous gene expression (Khromykh and Westaway 1997; Khromykh et al. 1998, 2000; Varnavski and Khromykh 1999; Varnavski et al. 2000).
Arthropod-borne virus encephalitis
Published in Avindra Nath, Joseph R. Berger, Clinical Neurovirology, 2020
The virus was originally isolated from a woman in the West Nile district of Uganda during a yellow fever survey [52]. Subsequently, it has disseminated widely. Cases have been reported from Egypt, Israel, South Africa, Romania, and the former Soviet Union, among other locations. In 1999 when the encephalitis made itself apparent in New York City, the virus caused a massive outbreak in the Volgograd region of Russia [53]. It reemerged causing human cases in Israel in 2000, and was the cause of equine encephalomyelitis in the Camargue, in France as well as in Italy in 1998. Kunjin virus, closely related to West Nile virus, is found in Southeast Asia and Australia [54]. Two main lineages of WNV exist, types I and II with type I most often causing human infection [55]. Strains seen in North America seem to be more often associated with neuroinvasive disease, but viral genetic drift cannot fully explain the apparent increased neuroinvasiveness [56].
Medical microbiology
Published in Lois N. Magner, Oliver J. Kim, A History of Medicine, 2017
Studies of West Nile fever, a disease transmitted by mosquitoes, demonstrated how easily pathogens could move from continent to continent in the jet age. West Nile virus was first discovered in 1937 in the West Nile district of Uganda; subsequently the disease was identified in Africa, Asia, Europe and the Middle East. Most infected people do not have serious symptoms, but the virus is a threat to people with a compromised immune system. In 1999, West Nile fever appeared in New York City where it caused more than 60 cases of meningoencephalitis and seven deaths. West Nile virus is a single-stranded RNA arbovirus (ARthropod-BOrne virus) in the Flaviviridae virus family which includes St. Louis encephalitis virus, Japanese encephalitis virus, Murray Valley encephalitis virus, and Kunjin virus.
Recent developments of RNA-based vaccines in cancer immunotherapy
Published in Expert Opinion on Biological Therapy, 2021
Elnaz Faghfuri, Farhad Pourfarzi, Amir Hossein Faghfouri, Mahdi Abdoli Shadbad, Khalil Hajiasgharzadeh, Behzad Baradaran
Numerous studies have verified that virus-derived saRNA can induce tumor rejection, long-term survival and even tumor prevention in various cancer models. For instance, intratumoral administration of Kunjin virus particles, which encode GM-CSF, could treat more than 50% of subcutaneous CT26 colon cancers and B16-OVA melanomas. Rejection of CT26 tumors was related to the stimulation of CTLs, which also rejected CT26 lung metastases [107]. Moreover, Venezuelan Equine Encephalitis (VEE) virus particles, which express PSCA (prostate stem cell antigen), have prevented tumors in a prostate cancer model. Notably, this enduring protective immune response was not associated with any measurable induction of autoimmunity [108]. It was recently found that vaccination with saRNA vectors could activate early strong type I IFN and IFN-induced response at the injection site, which might finally provide an adjuvant impact or decreased antigen expression. To specify the function of the early type I IFN response, saRNA vaccines were studied in IFN receptor knockout mice. The study has indicated that reducing the early type I IFN response may be a valuable approach to increase primary saRNA expression and the vaccine efficiency [109]. Loading of replicon RNA in chitosan NPs has led to effective delivery to DCs and subsequently stimulated immune response in vivo. In addition, in order to limit the host immune response stimulated by intermediate ds-RNA of saRNA, non-replicative mRNAs coding vaccinia virus immune evasion proteins E3, K3, and B18 were co-delivered. Combining all three vaccinia proteins caused inhibition of PKR and activation of the IFN pathway in vitro and increased expression of desired saRNA-encoded genes both in vitro and in vivo [110].