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To date, limited information is available on cytomegalovirus (CMV) and lymphocryptovirus (LCV) from Chlorocebus monkeys. We report here high detection rates of herpesviruses in free-roaming African green monkeys (AGMs, Chlorocebus sabaeus) (26.4%, 23/87) and in captive AGMs (75%, 3/4) with respiratory disease on the Caribbean Island of St. Kitts. LCV (81.25%) was more prevalent than CMV (18.75%) in the AGMs. Applying a bigenic PCR approach (targeting DNA polymerase (DPOL) and glycoprotein B (gB) genes), long sequences were obtained from representative AGM CMV (KNA-SD6) and LCV (KNA-E4, -N6 and -R15) samples, and mixed LCV infections were identified in KNA-N6 and -R15. The nucleotide (nt) sequence (partial DPOL-intergenic region-partial gB) and partial DPOL- and gB-amino acid (aa) sequences of AGM CMV KNA-SD6 were closely related to Cytomegalovirus cercopithecinebeta5 isolates from grivet monkeys, whilst those of AGM LCV KNA-E4 and -N6 (and E4-like gB of KNA-R15) were more closely related to cognate sequences of erythrocebus patas LCV1 from patas monkey than other LCVs, corroborating the concept of cospeciation in the evolution of CMV/LCV. On the other hand, the partial DPOL aa sequence of KNA-R15, and additional gB sequences (N6-gB-2 and R15-gB-2) from samples KNA-N6 and -R15 (respectively) appeared to be distinct from those of Old World monkey LCVs, indicating LCV evolutionary patterns that were not synchronous with those of host species. The present study is the first to report the molecular prevalence and genetic diversity of CMV/LCV from free-roaming/wild and captive AGMs, and is the first report on analysis of CMV nt/deduced aa sequences from AGMs and LCV gB sequences from Chlorocebus monkeys.

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Ebola virus disease (EVD) causes outbreaks and epidemics in West Africa that persist until today. The envelope glycoprotein of Ebola virus (GP) consists of two subunits, GP1 and GP2, and plays a key role in anchoring or fusing the virus to the host cell in its active form on the virion surface. Toremifene (TOR) is a ligand that mainly acts as an estrogen receptor antagonist; however, a recent study showed a strong and efficient interaction with GP. In this context, we aimed to evaluate the energetic affinity features involved in the interaction between GP and toremifene by computer simulation techniques using the Molecular Fractionation Method with Conjugate Caps (MFCC) scheme and quantum-mechanical (QM) calculations, as well as missense mutations to assess protein stability. We identified ASP522, GLU100, TYR517, THR519, LEU186, LEU515 as the most attractive residues in the EBOV glycoprotein structure that form the binding pocket. We divided toremifene into three regions and evaluated that region i was more important than region iii and region ii for the formation of the TOR-GP1/GP2 complex, which might control the molecular remodeling process of TOR. The mutations that caused more destabilization were ARG134, LEU515, TYR517 and ARG559, while those that caused stabilization were GLU523 and ASP522. TYR517 is a critical residue for the binding of TOR, and is highly conserved among EBOV species. Our results may help to elucidate the mechanism of drug action on the GP protein of the Ebola virus and subsequently develop new pharmacological approaches against EVD.Communicated by Ramaswamy H. Sarma.

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Abstract: human immunodeficiency virus type 1 (HIV-1) is the etiological agent of acquired immunodeficiency syndrome (AIDS), a pandemic with high economic and social costs. The envelope glycoprotein (ENV) of the virus mediates the infectious process by binding to and entering the host cell, one of the main target components of studies since its discovery. Its endodomain or C-terminal tail (CTT) participates in late replicative cycle processes, such as intracellular trafficking, activation, and cell death, which occurs because it interacts with multiple cellular factors through motifs or signal sequences present throughout its structure. Although these interactions have not been fully understood at specific levels, studies over more than three decades leave no doubtthatthis domain plays a fundamental role in the biology of the virus and probably the development of the disease. This review describes the studies carried out to date that demonstrate the importance of the CTT, focusing on the motifs responsible for its interactions and its possible roles in the pathogenicity of the infection.

Resumen: el virus de la inmunodeficiencia humana tipo 1 (VIH-1) es el agente etiológico del síndrome de inmunodeficiencia adguirida (SIDA), una pandemia con altos costos económicos y sociales. La glicoproteína de la envoltura (ENV) del virus media el proceso infeccioso al unirse a la célula huésped y entrar en ella, uno de los principales componentes objetivo de los estudios desde su descubrimiento. Su endodominio o cola C-terminal (CTT) participa en procesos tardíos del ciclo replicativo, como tráfico intracelular, activación y muerte celular, lo que ocurre porque interactúa con múltiples factores celulares a través de motivos o secuencias señal presentes en toda su estructura. Aunque estas interacciones no se han entendido completamente a niveles específicos, los estudios durante más de tres décadas no dejan dudas de que este campo juega un papel fundamental en la biología del virus y probablemente en el desarrollo de la enfermedad. Esta revisión describe los estudios realizados hasta la fecha que demuestran la importancia de la CTT, centrándose en los motivos responsables de sus interacciones y sus posibles roles en la patogenicidad de la infección.

Resumo: o vírus da imunodeficiência humana tipo 1 (HIV-1) é o agente etiológico da síndrome da imunodeficiência adquirida (AUXILIA), urna pandemia com elevados custos económicos e sociais. A glicoproteína do envelope (ENV) do vírus media o processo infeccioso ligando-se e entrando na célula hospedeira, um dos principais componentes alvo dos estudos desde sua descoberta. Seu endo domínio ou cauda C-terminal (CTT) participa de processos do ciclo replicativo tardio, como tráfego intracelular, ativação e morte celular, que ocorre porque interage com múltiplos fatores celulares por meio de motivos ou sequências-sinal presentes em toda a sua estrutura. Embora essas interações não tenham sido totalmente compreendidas em níveis específicos, estudos ao longo de mais de três décadas não deixam dúvidas de que esse domínio desempenha um papel fundamental na biologia do vírus e provavelmente no desenvolvimento da doença. Esta revisão descreve os estudos realizados até o momento que demonstram a importância da CTT, com foco nos motivos responsáveis por suas interações e seus possíveis papéis na patogenicidade da infecção.

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INTRODUCTION: Unlike most high-income countries where subtype B viruses predominate, the Cuban HIV-1 epidemic is characterized by a great diversity of subtypes and circulating recombinant forms. Some studies have shown that HIV variants exhibiting a preference for the CXCR4 co-receptor (X4-tropic) could have impacts on disease pathogenesis, with clinical implications for antiviral treatment plans. Determination of HIV co-receptor tropism is crucial for clinicians in deciding whether maraviroc is an appropriate antiviral. OBJECTIVE: Characterize V3 sequence variability and its relation to viral tropism across different subtypes circulating in Cuba and explore how this may affect treatment success with maraviroc. METHODS: We designed a cross-sectional study that included 72 plasma samples obtained at the Pedro Kourí Tropical Medicine Institute in Havana, Cuba. We sequenced the C2V3 env region and assessed subtype based both on env and pol sequences; tropism was predicted by Geno2pheno analysis. Additionally, 35 V3-loop Cuban sequences, obtained from a previous study, were incorporated into the analysis. Statistical associations among virological, clinical and epidemiological variables were assessed by a chi-square test. RESULTS: Tropism prediction for 72 variants revealed that CRF19_cpx was associated with dual-tropic R5X4 viruses (p = 0.034). Moreover, when 35 sequences from a former study were added, the association was significant not only for R5X4 (p = 0.019) but also for X4-tropic variants (p = 0.044). Alignment of 107 V3-loop sequences showed wide diversity among the different HIV-1 subtypes circulating in Cuba. CONCLUSIONS: In accordance with G2P, CRF19_cpx is a genetic variant with a high proportion of X4 and R5X4-tropic viruses. The results from the present study suggest that the Cuban recombinant could be a more pathogenic variant and that maraviroc may not be suitable for patients infected with CRF19_cpx.

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BACKGROUND: Dengue is one of the most important re-emerging viral diseases and the most common human arthropod-borne viral infection worldwide. Any of the four Dengue virus serotypes (DENV-1 to 4) can cause asymptomatic infections or clinical manifestations that range in severity from a mild, self-limited illness, to a severe disease characterized by a shock syndrome that can lead to death. Paraguay suffers periodic epidemic outbreaks of dengue since 1988 when the DENV-1 was introduced in the country. Epidemics caused by all four serotypes have been reported and the country. Although dengue is endemic in Paraguay, few studies have described the molecular epidemiology of DENV in the country, which is important to understand the local and global spread, as well as the evolution of this pathogen. METHODS: This was a cross-sectional study of a convenience sample. Suspected dengue patients of any age were recruited from the Emergency Laboratory of the Central Hospital of the Institute of Social Welfare, Asuncion, Paraguay, from February to June of 2011. A DENV antigen test was used to confirm the infection. The protein E gene sequences of isolated viruses were sequenced for phylogenetic analysis. RESULTS: Dengue was confirmed in 55.1% of the participants (n = 98/178). The most frequent clinical findings were fever, headache, and myalgia. Identity analyses of the protein E gene sequence of 56 viruses isolated showed the circulation of DENV-1 (n = 45) and DENV-2 (n = 11) in the Asuncion metropolitan area in 2011. Molecular epidemiology analyses suggest that DENV-1 was introduced into Paraguay from Argentina, while the DENV-2 from Brazil, replacing previous virus lineages. CONCLUSIONS: We have analyzed the molecular epidemiology of DENV-1 and DENV-2 isolated in Paraguay in 2011. We found strong evidence that DENV-1 was introduced into Paraguay from Argentina, while the DENV-2 from Brazil, replacing previous virus lineages. Molecular epidemiology studies are of great interest to analyze the dynamic of DENV spread, which are useful for early implementation of containment measures to reduce the risk of explosive epidemics caused by this virus.

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Asian macaques infected with simian immunodeficiency viruses (SIVs) isolated from African non-human primates develop a disease similar to human AIDS. SIV enters its target cells by binding to CD4 and a coreceptor, typically CCR5. Maraviroc is an entry inhibitor of human immunodeficiency virus type 1 (HIV-1) that prevents the interaction between CCR5 and the surface subunit gp120 of the viral envelope glycoprotein (Env). Thus far, the activity of maraviroc on SIV entry has been poorly studied. Here, we determined in vitro pharmacological parameters of the effect of maraviroc on the SIV Env association with CCR5. Cell-to-cell fusion inhibition assays were used to compare the susceptibility to maraviroc of the SIVsmmPBj Env-CCR5 interaction with that of HIV-1BaL Env. Analysis of dose-response curves and determination of IC50 values demonstrate that increasing concentrations of maraviroc inhibit the membrane fusion activity of SIVsmmPBj Env in a manner and to an extent similar to that of HIV-1BaL Env.

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OBJECTIVE: The chikungunya virus (CHIKV) is an arthropod-borne Alphavirus transmitted to humans, primarily via Aedes mosquitoes. In Puerto Rico, the first locally transmitted infections were reported in May 2014. Although the virus strain in Puerto Rico is related to the Asian/American lineage, many autochthonous cases have emerged recently in the Caribbean region (including Puerto Rico), raising the question of how CHIKV will evolve and adapt in PR. Taking the role of the envelope glycoprotein (E1) in viral evolution and transmission as a given, we analyzed the genetic diversity of the Puerto Rican (PR) E1 gene sequences and the phylogenetic relationships between those sequences and sequences from other parts of the world. MATERIALS AND METHODS: To analyze the overall genetic variation, 772 nucleotide sequences of the E1 gene were obtained from the Virus Pathogen Resource (ViPR). A maximum-likelihood analysis was performed to determine the phylogenetic relationships between the PR sequences and sequences from 48 countries around the world. RESULTS: The analysis of the E1 gene identified variations at 4 nucleotide positions, which included synonymous and nonsynonymous mutations. In addition, 2 nonsynonymous amino acid changes, T207M and S120L, were unique to the PR CHIKV sequences, and T155I was found to be shared by the PR (n = 3) and Colombia (n = 1) strains. CONCLUSION: Our analysis of the E1 gene revealed new molecular signatures in PR CHIKV sequences, 1 of which was also found in Colombia. While studies have shown possible relationships between T98A and A226V with viral adaptation and spread, no other PR sequence contained these vector-adaptive mutations. Thus, constant monitoring of the virus remains an essential factor in the establishment of control strategies to track viral spread.

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The expression of recombinant viral envelope glycoproteins in S2 (Drosophila melanogaster) has been performed with good results. This chapter contains protocols for the utilization of this system for the expression and analysis of proteins presented in cell plasma membrane.

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