Expression of frog virus 3 genes is impaired in mammalian cell lines

Frog virus 3 (FV3) is a large DNA virus that is the prototypic member of the family Iridoviridae. To examine levels of FV3 gene expression we generated a polyclonal antibody against the FV3 protein 75L. Following a FV3 infection in fathead minnow (FHM) cells 75L was found in vesicles throughout the cytoplasm as early as 3 hours post-infection. While 75L expressed strongly in FHM cells, our findings revealed no 75L expression in mammalian cells lines despite evidence of a FV3 infection. One explanation for the lack of gene expression in mammalian cell lines may be inefficient codon usage. As a result, 75L was codon optimized and transfection of the codon optimized construct resulted in detectable expression in mammalian cells. Therefore, although FV3 can infect and replicate in mammalian cell lines, the virus may not express its full complement of genes due to inefficient codon usage in mammalian species

Antibody dependent enhancement of frog virus 3 infection

<p>Abstract</p> <p>Background</p> <p>Viruses included in the family <it>Iridoviridae </it>are large, icosahedral, dsDNA viruses that are subdivided into 5 genera. Frog virus 3 (FV3) is the type species of the genus <it>Ranavirus </it>and the best studied iridovirus at the molecular level. Typically, antibodies directed against a virus act to neutralize the virus and limit infection. Antibody dependent enhancement occurs when viral antibodies enhance infectivity of the virus rather than neutralize it.</p> <p>Results</p> <p>Here we show that anti-FV3 serum present at the time of FV3 infection enhances infectivity of the virus in two non-immune teleost cell lines. We found that antibody dependent enhancement of FV3 was dependent on the Fc portion of anti-FV3 antibodies but not related to complement. Furthermore, the presence of anti-FV3 serum during an FV3 infection in a non-immune mammalian cell line resulted in neutralization of the virus. Our results suggest that a cell surface receptor specific to teleost cell lines is responsible for the enhancement.</p> <p>Conclusions</p> <p>This report represents the first evidence of antibody dependent enhancement in iridoviruses. The data suggests that anti-FV3 serum can either neutralize or enhance viral infection and that enhancement is related to a novel antibody dependent enhancement pathway found in teleosts that is Fc dependent.</p

Associations of Dietary Lipid-Soluble Micronutrients with Hepatic Steatosis among Adults in the United States

Lipid-soluble micronutrients may be beneficial to non-alcoholic fatty liver disease due to their important roles in metabolism and maintaining tissue functions. Utilizing 2017–2018 National Health and Nutrition Examination Survey, this study examined the potential overall and race/ethnicity-specific (black, Hispanic and white) associations of dietary lipid-soluble micronutrients (α-tocopherol, retinol, vitamin D, β-carotene and total carotenoids) with hepatic steatosis. The analysis included 4376 adults (1037 blacks, 981 Hispanics, 1549 whites) aged ≥20 years who completed the transient elastography examination with dietary data available. Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated using logistic regressions. The age-adjusted prevalence of steatosis was 20.9% for blacks, 34.0% for Hispanics and 28.7% for whites. Overall, dietary α-tocopherol was inversely associated with steatosis (highest vs. lowest quartile: OR = 0.51, 95%CI = 0.35–0.74, Ptrend = 0.0003). The associations remained significant among blacks (highest vs. lowest tertile: OR = 0.45, 95%CI = 0.26–0.77, Ptrend = 0.002) and whites (highest vs. lowest tertile: OR = 0.56, 95%CI = 0.33–0.94, Ptrend = 0.02). Higher α-tocopherol intake was associated with lower odds of steatosis among all (Ptrend = 0.016) and black participants (Ptrend = 0.003) classified as never/rare/occasional alcohol drinkers. There was a trend suggesting higher β-carotene intake with lower odds of steatosis (Ptrend = 0.01). Our results suggest potential protective effects of dietary vitamin E as α-tocopherol on steatosis particularly among blacks

Comparative genomic analysis of the family Iridoviridae: re-annotating and defining the core set of iridovirus genes

BACKGROUND: Members of the family Iridoviridae can cause severe diseases resulting in significant economic and environmental losses. Very little is known about how iridoviruses cause disease in their host. In the present study, we describe the re-analysis of the Iridoviridae family of complex DNA viruses using a variety of comparative genomic tools to yield a greater consensus among the annotated sequences of its members. RESULTS: A series of genomic sequence comparisons were made among, and between the Ranavirus and Megalocytivirus genera in order to identify novel conserved ORFs. Of these two genera, the Megalocytivirus genomes required the greatest number of altered annotations. Prior to our re-analysis, the Megalocytivirus species orange-spotted grouper iridovirus and rock bream iridovirus shared 99% sequence identity, but only 82 out of 118 potential ORFs were annotated; in contrast, we predict that these species share an identical complement of genes. These annotation changes allowed the redefinition of the group of core genes shared by all iridoviruses. Seven new core genes were identified, bringing the total number to 26. CONCLUSION: Our re-analysis of genomes within the Iridoviridae family provides a unifying framework to understand the biology of these viruses. Further re-defining the core set of iridovirus genes will continue to lead us to a better understanding of the phylogenetic relationships between individual iridoviruses as well as giving us a much deeper understanding of iridovirus replication. In addition, this analysis will provide a better framework for characterizing and annotating currently unclassified iridoviruses

The Genomic Diversity and Phylogenetic Relationship in the Family Iridoviridae

The Iridoviridae family are large viruses (∼120–200 nm) that contain a linear double-stranded DNA genome. The genomic size of Iridoviridae family members range from 105,903 bases encoding 97 open reading frames (ORFs) for frog virus 3 to 212,482 bases encoding 211 ORFs for Chilo iridescent virus. The family Iridoviridae is currently subdivided into five genera: Chloriridovirus, Iridovirus, Lymphocystivirus, Megalocytivirus, and Ranavirus. Iridoviruses have been found to infect invertebrates and poikilothermic vertebrates, including amphibians, reptiles, and fish. With such a diverse array of hosts, there is great diversity in gene content between different genera. To understand the origin of iridoviruses, we explored the phylogenetic relationship between individual iridoviruses and defined the core-set of genes shared by all members of the family. In order to further explore the evolutionary relationship between the Iridoviridae family repetitive sequences were identified and compared. Each genome was found to contain a set of unique repetitive sequences that could be used in future virus identification. Repeats common to more than one virus were also identified and changes in copy number between these repeats may provide a simple method to differentiate between very closely related virus strains. The results of this paper will be useful in identifying new iridoviruses and determining their relationship to other members of the family

A Conceptual Framework for Social, Behavioral, and Environmental Change through Stakeholder Engagement in Water Resource Management

Incorporating stakeholder engagement into environmental management may help in the pursuit of novel approaches for addressing complex water resource problems. However, evidence about how and under what circumstances stakeholder engagement enables desirable changes remains elusive. In this paper, we develop a conceptual framework for studying social and environmental changes possible through stakeholder engagement in water resource management, from inception to outcomes. We synthesize concepts from multiple literatures to provide a framework for tracing linkages from contextual conditions, through engagement process design features, to social learning, community capacity building, and behavioral change at individual, group, and group network levels, and ultimately to environmental change. We discuss opportunities to enhance the framework including through empirical applications to delineate scalar and temporal dimensions of social, behavioral, and environmental changes resulting from stakeholder engagement, and the potential for negative outcomes thus far glossed over in research on change through engagement

Accumulation of Endogenous LITAF in Aggresomes

LITAF is a 161 amino acid cellular protein which includes a proline rich N-terminus and a conserved C-terminal domain known as the simple-like domain. Mutations in LITAF have been identified in Charcot-Marie tooth disease, a disease characterized by protein aggregates. Cells transfected with cellular LITAF reveal that LITAF is localized to late endosomes/lysosomes. Here we investigated the intracellular localization of endogenous LITAF. We demonstrated that endogenous LITAF accumulates at a discrete cytoplasmic site in BGMK cells that we identify as the aggresome. To determine the domain within LITAF that is responsible for the localization of LITAF to aggresomes, we created a construct that contained the C-terminal simple-like domain of LITAF and found that this construct also localizes to aggresomes. These data suggest the simple-like domain is responsible for targeting endogenous LITAF to the aggresome

Multi-ancestry study of blood lipid levels identifies four loci interacting with physical activity.

Many genetic loci affect circulating lipid levels, but it remains unknown whether lifestyle factors, such as physical activity, modify these genetic effects. To identify lipid loci interacting with physical activity, we performed genome-wide analyses of circulating HDL cholesterol, LDL cholesterol, and triglyceride levels in up to 120,979 individuals of European, African, Asian, Hispanic, and Brazilian ancestry, with follow-up of suggestive associations in an additional 131,012 individuals. We find four loci, in/near CLASP1, LHX1, SNTA1, and CNTNAP2, that are associated with circulating lipid levels through interaction with physical activity; higher levels of physical activity enhance the HDL cholesterol-increasing effects of the CLASP1, LHX1, and SNTA1 loci and attenuate the LDL cholesterol-increasing effect of the CNTNAP2 locus. The CLASP1, LHX1, and SNTA1 regions harbor genes linked to muscle function and lipid metabolism. Our results elucidate the role of physical activity interactions in the genetic contribution to blood lipid levels