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Order Martellivirales: Togaviridae
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
The Alphavirus members are mosquito-borne viruses. Most alphaviruses are cytopathic to vertebrates such as humans, nonhuman primates, equids, birds, amphibians, reptiles, rodents, and pigs and cause in humans a short febrile illness that can lead to prolonged arthritis or encephalitis but is rarely fatal. There are two aquatic alphaviruses, southern elephant seal virus and salmon pancreas disease virus, often referred to as salmonid alphavirus (SAV), infecting sea mammals and fish, respectively.
Encephalitis and Its Mimics in the Critical Care Unit
Published in Cheston B. Cunha, Burke A. Cunha, Infectious Diseases and Antimicrobial Stewardship in Critical Care Medicine, 2020
Chikungunya similarly remains very rare in the United States but is widely prevalent elsewhere in the Americas. Unlike most of the other viruses discussed, most patients infected with this alphavirus are symptomatic [35]. Most are febrile with severe, widespread arthralgias symmetrically affecting multiple joints. While neurologic involvement occurs in only about 10%–15% of cases, primarily affecting individuals above the age of 60, encephalitis is a relatively common nervous system manifestation. Specific details remain unclear, particularly since encephalopathy is very common in these patients and encephalitis and encephalopathy have not always been clearly distinguished in reported series.
Viruses
Published in Loretta A. Cormier, Pauline E. Jolly, The Primate Zoonoses, 2017
Loretta A. Cormier, Pauline E. Jolly
Togaviridae consists of two genera: Alphavirus and Rubivirus. The latter is the agent of Rubella and appears to be specific to human hosts. There are over 30 species of Alphavirus, which are typically mosquito-borne, and infect mammals, fish, birds, and invertebrates (Markoff 2015). Many of the alphaviruses are of concern as emerging and re-emerging infections, and a number of alphaviruses that infect humans also infect wild primates.
Semliki Forest virus-based immunotherapy for cancer
Published in Expert Opinion on Biological Therapy, 2020
Alphaviruses belong to the family of Togaviridae and hold a single-stranded RNA (ssRNA) genome surrounded by a protein capsid structure and spike membrane proteins [9]. The alphavirus lifecycle is characterized by a large host range due to recognition of several cell surface receptors, direct RNA replication in the host cell cytoplasm and release of progeny by budding [10]. Alphaviruses have been associated with epidemics in different parts of the world resulting in fever, severe persistent headache, myalgia and arthralgia [11,12]. Moreover, recent outbreaks of Chikungunya virus (CHIK) have occurred presenting clinical symptoms such as polyarthralgia, rash, high fever and severe headaches, which have been characterized by rapid spread and high morbidity [13]. For this reason, alphavirus expression systems based on attenuated or avirulent strains and replication-deficient viruses have been engineered for immunization approaches demonstrating no harm to humans. In this context, alphavirus vectors have been frequently used for recombinant protein expression in cell lines [14], in primary cells [15], and in vivo[16]. Furthermore, alphavirus vectors have been applied for numerous immunization studies in animal models [8]. The aim of the review is to give an overview of the current status of alphavirus-based cancer immunotherapy by a description of alphavirus vector and expression systems and their applications in preclinical animal models and some clinical trials.
Zika virus, vaccines, and antiviral strategies
Published in Expert Review of Anti-infective Therapy, 2018
Sophie Masmejan, David Baud, Didier Musso, Alice Panchaud
It should be kept in mind that ZIKV is mainly a vector-borne pathogen transmitted by Aedes mosquitoes. The development of drugs and vaccines can take decades. To date, development of anti-Flavivirus drugs has been unsuccessful and, as previously mentioned, the evaluation of anti-ZIKV vaccine will be challenging in the context of ZIKV circulation decline. In our opinion, the strategy to prevent new ZIKV emergence or re-emergence should focus on Aedes mosquito control, keeping in mind that ZIKV always co-circulate with other arboviruses (Alphavirus and Flavivirus) and that decreasing the density of Aedes mosquitoes can have an impact of ZIKV infection but also on all arboviruses with Aedes as main vectors such as DENV, CHIKV, or YFV. To this end, several new vector-borne control strategies are in development, with successful reduction of Aedes population already obtained in some large-scale experimentations [23,87].
Emergence of mRNA vaccines in the management of cancer
Published in Expert Review of Vaccines, 2023
Mohamad Irfan Mohamad Razif, Nabilah Nizar, Nur Hannah Zainal Abidin, Syasya Nasuha Muhammad Ali, Wan Nurul Najihah Wan Zarimi, Junaidi Khotib, Deny Susanti, Muhammad Taufiq Mohd Jailani, Muhammad Taher
There is a type of mRNA vaccine that employs a SAM derived from an alphavirus genome [10]. This type of mRNA contains the genes that encode the replication machinery of the alphavirus RNA but are deficient in the genes which encode the viral structural proteins that are necessary to produce an infectious alphavirus particle. Based on their research, compared to administration of unformulated RNA, SAM enclosed within an LNP significantly boosted the immunogenicity. Therefore, with the protective immune response induced by this SAM, this type of mRNA vaccine was shown to be comparable to those induced by viral delivery technologies [10].