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Venezuelan equine encephalitis virus (VEEV) is a pathogenic alphavirus, which circulates in the Central, South, and North Americas, including the United States, and represents a significant public health threat. In recent years, strong progress has been made in understanding the structure of VEEV virions, but the mechanism of their formation has yet to be investigated. In this study, we analyzed the functions of different capsid-specific domains and its amino-terminal subdomains in viral particle formation. Our data demonstrate that VEEV particles can be efficiently formed directly at the plasma membrane without cytoplasmic nucleocapsid preassembly. The entire amino-terminal domain of VEEV capsid protein was found to be dispensable for particle formation. VEEV variants encoding only the capsid's protease domain efficiently produce genome-free VEEV virus-like particles (VLPs), which are very similar in structure to the wild-type virions. The amino-terminal domain of the VEEV capsid protein contains at least four structurally and functionally distinct subdomains, which mediate RNA packaging and the specificity of packaging in particular. The most positively charged subdomain is a negative regulator of the nucleocapsid assembly. The three other subdomains are not required for genome-free VLP formation but are important regulators of RNA packaging. Our data suggest that the positively charged surface of the VEEV capsid-specific protease domain and the very amino-terminal subdomain are also involved in interaction with viral RNA and play important roles in RNA encapsidation. Finally, we show that VEEV variants with mutated capsid acquire compensatory mutations in either capsid or nsP2 genes. [ABSTRACT FROM AUTHOR]

Venezuelan equine encephalitis virus (VEEV) represents a continuous public health threat in the United States. It has the ability to cause fatal disease in humans and in horses and other domestic animals. We recently demonstrated that replicating VEEV interferes with cellular transcription and uses this phenomenon as a means of downregulating a cellular antiviral response. VEEV capsid protein was found to play a critical role in this process, and its ~35-amino-acid-long peptide, fused with green fluorescent protein, functioned as efficiently as did the entire capsid. We detected a significant fraction of VEEV capsid associated with nuclear envelope, which suggested that this protein might regulate nucleocytoplasmic trafficking. In this study, we demonstrate that VEEV capsid and its N-terminal sequence efficiently inhibit multiple receptor-mediated nuclear import pathways but have no effect on the passive diffusion of small proteins. The capsid protein of the Old World alphavirus Sindbis virus and the VEEV capsid, with a previously defined frameshift mutation, were found to have no detectable effect on nuclear import. Importantly, the VEEV capsid did not noticeably interfere with nuclear import in mosquito cells, and this might play a critical role in the ability of the virus to develop a persistent, life-long infection in mosquito vectors. These findings demonstrate a new aspect of VEEV-host cell interactions, and the results of this study are likely applicable to other New World alphaviruses, such as eastern and western equine encephalitis viruses. [ABSTRACT FROM AUTHOR]

The encephalitogenic New World alphaviruses, including Venezuelan (VEEV), eastern (EEEV), and western equine encephalitis viruses, constitute a continuing public health threat in the United States. They circulate in Central, South, and North America and have the ability to cause fatal disease in humans and in horses and other domestic animals. We recently demonstrated that these viruses have developed the ability to interfere with cellular transcription and use it as a means of downregulating a cellular antiviral response. The results of the present study suggest that the N-terminal, ∼35-amino-acid-long peptide of VEEV and EEEV capsid proteins plays the most critical role in the downregulation of cellular transcription and development of a cytopathic effect. The identified VEEV-specific peptide CVEE33-68 includes two domains with distinct functions: the α-helix domain, helix I, which is critically involved in supporting the balance between the presence of the protein in the cytoplasm and nucleus, and the downstream peptide, which might contain a functional nuclear localization signal(s). The integrity of both domains not only determines the intracellular distribution of the VEEV capsid but is also essential for direct capsid protein functioning in the inhibition of transcription. Our results suggest that the VEEV capsid protein interacts with the nuclear pore complex, and this interaction correlates with the protein's ability to cause transcriptional shutoff and, ultimately, cell death. The replacement of the N-terminal fragment of the VEEV capsid by its Sindbis virus-specific counterpart in the VEEV TC-83 genome does not affect virus replication in vitro but reduces cytopathogenicity and results in attenuation in vivo. These findings can be used in designing a new generation of live, attenuated, recombinant vaccines against the New World alphaviruses. [ABSTRACT FROM AUTHOR]

Background: Depression is a common and treatable illness in late-life. However, many do not seek treatment and may suffer from the stigma of the illness, which may vary across cultures. The aim of this study was to compare attitudes about depression in primary care practices in South Korea, Russia, and the USA., Methods: A cross-sectional study was undertaken using a self-administered questionnaire and PHQ-9 diagnostic survey with 1,094 patients aged 60-93 years who attended a primary care clinic in Korea, Russia, or the USA., Results: The mean age of participants was 71 years, with 61% being female. US patients were older and had higher education levels. Russian participants were more likely to be widowed and had lower self-rated health. The majority of participants agreed that depression is a kind of disease (Korea 77%, Russia 61%, USA 79%). Only 6% of US patients believed depression means a person is weak, compared to 78% (Korea) and 61% (Russia). Fewer US patients endorsed depression as a normal part of aging (29% vs. Korea at 42% and Russia at 54%). Among participants in the USA, age correlated negatively with endorsement of a medical model of depression (p = <0.001)., Conclusions: Though there was wide variation between countries in attitudes about depression, the majority of each endorsed items reflected a medical model of depression. Korean and Russian participants endorsed the view of depression as a personal weakness more than participants in the USA. Demographic correlates of negative attitudes about depression were moderate to weak.