The host-targeting compound peruvoside has a broad-spectrum antiviral activity against positive-sense RNA viruses

Positive-sense RNA viruses modify intracellular calcium stores, endoplasmic reticulum and Golgi apparatus (Golgi) to generate membranous replication organelles known as viral factories. Viral factories provide a conducive and substantial enclave for essential virus replication via concentrating necessary cellular factors and viral proteins in proximity. Here, we identified the vital role of a broad-spectrum antiviral, peruvoside in limiting the formation of viral factories. Mechanistically, we revealed the pleiotropic cellular effect of Src and PLC kinase signaling via cyclin-dependent kinase 1 signaling leads to Golgi-specific brefeldin A-resistance guanine nucleotide exchange factor 1 (GBF1) phosphorylation and Golgi vesiculation by peruvoside treatment. The ramification of GBF1 phosphorylation fosters GBF1 deprivation consequentially activating downstream antiviral signaling by dampening viral factories formation. Further investigation showed signaling of ERK1/2 pathway via cyclin-dependent kinase 1 activation leading to GBF1 phosphorylation at Threonine 1337 (T1337). We also showed 100% of protection in peruvoside-treated mouse model with a significant reduction in viral titre and without measurable cytotoxicity in serum. These findings highlight the importance of dissecting the broad-spectrum antiviral therapeutics mechanism and pave the way for consideration of peruvoside, host-directed antivirals for positive-sense RNA virus-mediated disease, in the interim where no vaccine is available.

VIH y SARS-CoV-2: aspectos a considerar para enfrentar esta nueva pandemia / HIV and SARS-CoV-2: points to consider to face this new pandemic

En diciembre de 2019 una nueva especie de ß-coronavirus causante de neumonía fue identificada en la ciudad China de Wuhan, el cual posteriormente fue denominado SARS-CoV-2. Este virus de ácido ribonucleico presenta ciertas similitudes con otros virus del mismo material genético, dentro de ellos se ha visto que la infección por virus de la inmunodeficiencia humana se asemeja en diversos aspectos a la infección por SARS-CoV-2. En este comentario presentamos algunas de las similitudes virológicas, inmunológicas, clínicas y farmacológicas entre estos dos virus, las cuales podrían permitirnos entender de mejor manera la inmunopatogenia de COVID-19, así como también tomar algunas decisiones en cuanto al manejo antiviral.

In December 2019, a new species of pneumonia-causing betacoronavirus was identified in Wuhan, China, which was later identified as SARS-CoV-2. This RNA virus presents certain similarities with other viruses of the same genetic material. It has been seen that infection by human immunodeficiency virus resembles the infection by SARS-CoV-2 in various aspects. In this comment, we present some of the virological, immunological, clinical, and pharmacological similarities between HIV and SARS-CoV-2, which could allow us to understand the immunopathogenesis of COVID-19 better, as well as make some decisions in regarding antiviral management.

Understanding the Influence Factors in Viral Nucleic Acid Test of 2019 novel Coronavirus (2019-nCoV) / 中华检验医学杂志

At present, the prevention and control of new coronavirus has entered a critical period. However, the use of quantitative real-time PCR (qRT-PCR) assays for the detection of viral nucleic acid, as a crucial diagnostic approach, has been doubted in clinical practice. Herein, we have reviewed the current status of epidemic prevention and control, latest development of detection technologies, disease characteristics, clinical sampling and transport. We have also discussed the factors that may affect the performance of viral nucleic acid detection, and suggested some effective methods to improve the detection performance of the assays.

COINFECCIÓN NATURAL DE VIRUS DE ARN EN CULTIVOS DE PAPA (Solanum tuberosum subsp. Andigena) EN ANTIOQUIA (COLOMBIA) / Natural coinfection of RNA viruses in potato (Solanum tuberosum subsp. Andigena) crops in Antioquia (Colombia)

RESUMEN Las enfermedades virales son uno de los principales problemas fitopatológicos de la papa. Con el fin de determinar los virus más prevalentes en cultivos de papa var. Diacol Capiro en el oriente Antioqueño (Colombia), se evaluó mediante RT-qPCR la presencia de diez virus de ARN (PVY, PVA, PVV, TaLMV, PVS, PLRV, PYVV, PVX, ToRSV y PMTV) en 36 muestras de tejido foliar. Los resultados indicaron la ocurrencia de cinco de los diez virus evaluados, con niveles de prevalencia de 88,9 %, 75 %, 75 %, 41,7 % y 25 % para PVY, PVX, PYVV, PLRV y PVS, respectivamente. Con fines comparativos, cuatro virus también se evaluaron mediante ELISA, siendo detectados PVS (80,5 %), PVY (55 %) y PLRV (5,5 %); mientras que PVX no fue encontrado con esta prueba. La comparación de estas técnicas mediante la razón de prevalencia (RP), indicó que la RT-qPCR ofrece niveles superiores de detección con valores de RP = 1,6 y RP = 7,5 para los virus PVY y PLRV; mientras que para PVS la ELISA detectó más muestras positivas que RT-qPCR (RP = 3,22), evidenciándose la necesidad de diseñar nuevos cebadores ajustados a la diversidad de este virus en Antioquia. La coinfección mixta más frecuente fue PVY-PYVV-PVX (22,2 %), mientras que los cinco virus se encontraron en el 11,1 % de las muestras. Finalmente, utilizando secuenciación Sanger de la cápside y NGS para los genomas completos, se confirmó la circulación de todos los virus detectados en los cultivos de papa del oriente Antioqueño. Estos resultados señalan la necesidad de fortalecer los programas de manejo integrado de enfermedades virales en Antioquia.

ABSTRACT Viral diseases are one of the main phytopathological problems affecting potato crops worldwide. To determine the most prevalent viruses in potato var. Diacol Capiro crops in Eastern Antioquia, 36 leaf samples were tested for the presence of PVY, PVA, PVV, TaLMV, PVS, PLRV, PYVV, PVX, ToRSV and PMTV using RT-qPCR. Detected viruses included PVY, PVX, PYVV, PLRV and PVS with prevalence levels of 88.9 %, 75.0 %, 75.0 %, 41.7 % and 25.0 %, respectively. PVS, PVY, PLRV and PVX were also tested by ELISA. PVS, PVY and PLRV tested positive in 80.5 %, 55.0 % and 5.5 % of samples; PVX was not detected. Prevalence Ratios (PR) suggests that detection is higher for PVY (PR = 1.6) and PLRV (PR = 7.5) using RT-qPCR. ELISA worked better for PVS with a PR of 3.2; this result suggests that the RT-qPCR primers used for PVS must be adjusted to reflect the genome diversity of virus in Antioquia. The most frequent coinfection was PVY-PYVV-PVX, which occurred in 22.2 % of samples; coinfection with PVY, PVX, PYVV, PLRV and PVS was present in 11.1 % of samples. The circulation of these viruses in Eastern Antioquia was further confirmed using Sanger and high-throughput sequence. This work highlights the need to strengthen integrated disease management programs of viruses in Antioquia.

Brote de síndrome pulmonar por hantavirus, Tucumán, Argentina / Outbreak of hantavirus pulmonary syndrome in Tucumán, Argentina

Se describe un brote de síndrome pulmonar por hantavirus en el departamento de Burruyacú, provincia de Tucumán. La detección en 2016 de un caso de hantavirosis en una joven de 23 años -en ese momento considerado el primero ocurrido en dicha provincia- promovió un estudio epidemiológico exhaustivo, que permitió detectar retrospectivamente otro caso ocurrido en un niño de 5 años, un mes antes, en el mismo departamento. La infección fue confirmada por serología en ambos casos (caso 1 en muestras de 4 y 7 días de evolución, caso 2 en muestra a los 4 días). En ambos casos el genotipo viral fue caracterizado como HU39694 y los contactos fueron serológicamente negativos. En las áreas fueron identificados roedores pertenecientes a los géneros Akodon y Calomys y a la especie Mus musculus, pero no a Oligoryzomys, el reservorio habitual del genotipo HU39694. Tampoco se detectaron anticuerpos anti-hantavirus en suero de los roedores capturados. La ausencia de registro de viajes a área endémica de este genotipo y los hábitos recreacionales de los pacientes, sumados a los resultados serológicos negativos para hantavirus en los contactos, permiten inferir la posible exposición de los pacientes a fluidos de roedores infectados durante actividades recreativas o sociales al aire libre en sus respectivas áreas de residencia. En conclusión, se demuestra la circulación en Tucumán del genotipo viral HU39694, hasta ahora considerado restringido a la región pampeana central. Se extiende así a Tucumán el área endémica de hantavirosis, pero no se identificó el reservorio en el área.

We describe an outbreak of hantavirus pulmonary syndrome in the Burruyacú Department, Province of Tucumán. The detection in 2016 of a case of hantavirosis affecting a 23-year-old woman, considered at that time to be the first case occurred in that province, promoted a thorough epidemiological study. The investigation allowed the retrospective detection of another case occurred one month earlier in a 5-year-old child in the same Department. In both cases, the infection was confirmed by serology (case 1 at days 4 and 7 of disease onset, case 2 at day 4) and the viral genotype was characterized as HU39694. The contacts of both cases were serologically negative for hantavirus. The rodents captured in the area belonged to genus Akodon, genus Calomys and species Mus musculus. Oligoryzomys, the known reservoir for this viral genotype, was not found. Specific anti-hantavirus antibodies were not detected in the captured rodents. Given that the patients had not visited hantavirus endemic areas and their contacts were negative for hantavirus, we infer that the patients were locally exposed to fluids of infected rodents during their usual social or recreational outdoor activities. In conclusion, we demonstrate that hantavirus HU39694 -a genotype until now considered to be restricted to the Central Pampas of the country- is circulating in the North Western province of Tucumán. The endemic area of hantavirosis is thus expanded to this province but the viral reservoir in the area has not yet been identified.

RNA viruses in trypanosomatid parasites: a historical overview

Viruses of trypanosomatids are now being extensively studied because of their diversity and the roles they play in flagellates' biology. Among the most prominent examples are leishmaniaviruses implicated in pathogenesis of Leishmania parasites. Here, we present a historical overview of this field, starting with early reports of virus-like particles on electron microphotographs, and culminating in detailed molecular descriptions of viruses obtained using modern next generation sequencing-based techniques. Because of their diversity, different life cycle strategies and host specificity, we believe that trypanosomatids are a fertile ground for further explorations to better understand viral evolution, routes of transitions, and molecular mechanisms of adaptation to different hosts.

Internal control for real-time polymerase chain reaction based on MS2 bacteriophage for RNA viruses diagnostics

BACKGROUND Real-time reverse transcription polymerase chain reaction (RT-PCR) is routinely used to detect viral infections. In Brazil, it is mandatory the use of nucleic acid tests to detect hepatitis C virus (HCV), hepatitis B virus and human immunodeficiency virus in blood banks because of the immunological window. The use of an internal control (IC) is necessary to differentiate the true negative results from those consequent from a failure in some step of the nucleic acid test. OBJECTIVES The aim of this study was the construction of virus-modified particles, based on MS2 bacteriophage, to be used as IC for the diagnosis of RNA viruses. METHODS The MS2 genome was cloned into the pET47b(+) plasmid, generating pET47b(+)-MS2. MS2-like particles were produced through the synthesis of MS2 RNA genome by T7 RNA polymerase. These particles were used as non-competitive IC in assays for RNA virus diagnostics. In addition, a competitive control for HCV diagnosis was developed by cloning a mutated HCV sequence into the MS2 replicase gene of pET47b(+)-MS2, which produces a non-propagating MS2 particle. The utility of MS2-like particles as IC was evaluated in a one-step format multiplex real-time RT-PCR for HCV detection. FINDINGS We demonstrated that both competitive and non-competitive IC could be successfully used to monitor the HCV amplification performance, including the extraction, reverse transcription, amplification and detection steps, without compromising the detection of samples with low target concentrations. In conclusion, MS2-like particles generated by this strategy proved to be useful IC for RNA virus diagnosis, with advantage that they are produced by a low cost protocol. An attractive feature of this system is that it allows the construction of a multicontrol by the insertion of sequences from more than one pathogen, increasing its applicability for diagnosing different RNA viruses.

Broad spectrum inhibitors of 3C and 3CL proteases:research advances / 国际药学研究杂志

Picornaviruses(PV)and coronaviruses(CoV) are positive-stranded RNA viruses. Pathogens in the family can cause hand,foot and mouth disease,myocarditis, common cold ,severe respiratory and intestinal diseases. 3C and 3CL proteases, belonging to cysteine proteases,are required to process polyproteins into mature proteins for viral replication,which plays an impor?tant role in viral replication because substrate binding sites are highly conservative and have similar catalytic mechanism. 3C and 3CL proteases are different from protease in the human body ,which represents a promising anti-viral drug target. Using 3C and 3CL pro?teinase structural similarities,broad spectrum protease inhibitors have been found successfully. This review describes recent develop?ments of broad spectrum protease inhibitors targeting on 3C and 3CL proteases,and briefly illustrates the mechanism of the inhibitors, which may benefit to the development of virus therapy.

Broad spectrum inhibitors of 3C and 3CL proteases: Research advances / 国际药学研究杂志

Picornaviruses (PV) and coronaviruses (CoV) are positive-stranded RNA viruses. Pathogens in the family can cause hand, foot and mouth disease, myocarditis, common cold, severe respiratory and intestinal diseases. 3C and 3CL proteases, belonging to cysteine proteases, are required to process polyproteins into mature proteins for viral replication, which plays an important role in viral replication because substrate binding sites are highly conservative and have similar catalytic mechanism. 3C and 3CL proteases are different from protease in the human body, which represents a promising anti-viral drug target. Using 3C and 3CL proteinase structural similarities, broad spectrum protease inhibitors have been found successfully. This review describes recent developments of broad spectrum protease inhibitors targeting on 3C and 3CL proteases, and briefly illustrates the mechanism of the inhibitors, which may benefit to the development of virus therapy.

Emerging of RNA Viruses: A Threat of Epidemics Around-The-Clock.

Viral infections are global public health concern and RNA viruses are the major cause of morbidity and mortality across the world due to their high error rate of replication and better adaptability inside the host cell. Some of the recent viral outbreaks around the globe are mainly hepatitis and its subtypes, influenza and its subtypes, Japanese encephalitis, dengue, ebola and the chikungunya. Vaccines are available only for some of these diseases. Therefore, organisation comprising WHO in accordance with the International Health Regulations of 2005 keeps on to track the evolving infectious diseases and the Global Outbreak Alert and Response Network, establishes the human and technical resources to diagnose these outbreaks and thereby check the virus growth. In this review article, we are discussing the outbreaks, precautions along with the appropriate preparedness of individual as well as the government for dealing with these viral diseases.

Application of combined detection of enterovirus nucleic acid and antibody in early etiological diagnosis for hand-foot-and-mouth disease / 中华检验医学杂志

Objective To assess the value of combined detection of enterovirus nucleic acid and antibody in early etiological diagnosis for hand-foot-and-mouth disease ( HFMD).Methods A case-control study was conducted.A total of 1 066 cases of children clinically diagnosed with HFMD from Hangzhou Children′s Hospital were involved into the research group from January to June 2014, consisting of 401 common cases and 665 severe cases; Throat swabs and serum samples from these children underwent combined detection for EV71/CA16/EV of enterovirus nucleic acid by fluorescence quantitative RT-PCR and for EV71/CA16-IgM by ELISA.All data were analyzed with SPSS 16.0.Results The total positive rate of enterovirus nucleic acid EV71/CA16/EV by fluorescence quantitative RT-PCR in the 1 066 cases of children clinically diagnosed with HFMD was 75.52%( 805/1 066 ) ( 95%CI: 72.80%-78.05%).But the total positive rate of combined detection was 91.46%( 975/1 066 ) ( 95%CI:89%.58-93.04%).The total positive rate of combined detection is higher than that of RT-PCR test(χ2 =98.338,P=0.000).The positive rate of EV71 type of combined detection was 64.63%(689/1 066)(95%CI:61.67%-67.49%),which is 15.38%higher than that of RT-PCR test 49.25%(525/1 066)(95%CI:46.21%-52.29%)(χ2 =51.453, P=0.000).In 665 severe cases of HFMD, the total positive rate of combined detection was 96.69%(643/665)(95%CI:94.95%-97.87%), which is higher than that of RT-PCR test 79.25%(527/665)(95%CI:75.92%-82.22%)(χ2 =95.607, P =0.000).In the severe cases, the positive rate of EV71 type of combined detection was 87.52%( 582/665 ) ( 95%CI:84.71%-89.89%) , which is 18.95% higher than that of RT-PCR test 68.57%(456/665) (95%CI:64.87%-72.06%) (χ2 =69.665, P=0.000).In the fatal cases, the positive rate of EV71 type of combined detection was 95.92%(94/98) (95%CI:89.28%-98.68%).Conclusions The combined detection of enterovirus nucleic acid and specific IgM antibody can significantly increase the positive rate of HFMD, especially for severe cases.The combine detection increases both the total positive rate and EV71 positive rate.Thus it has a high potential for becoming a new guidelines for laboratory diagnosis of HFMD.

Role of inducible nitric oxide synthase on the development of virus-associated asthma exacerbation which is dependent on Th1 and Th17 cell responses

Asthma is characterized by airway inflammation induced by immune dysfunction to inhaled antigens. Although respiratory viral infections are the most common cause of asthma exacerbation, immunologic mechanisms underlying virus-associated asthma exacerbation are controversial. Clinical evidence indicates that nitric oxide (NO) levels in exhaled air are increased in exacerbated asthma patients compared to stable patients. Here, we evaluated the immunologic mechanisms and the role of NO synthases (NOSs) in the development of virus-associated asthma exacerbation. A murine model of virus-associated asthma exacerbation was established using intranasal challenge with ovalbumin (OVA) plus dsRNA for 4 weeks in mice sensitized with OVA plus dsRNA. Lung infiltration of inflammatory cells, especially neutrophils, was increased by repeated challenge with OVA plus dsRNA, as compared to OVA alone. The neutrophilic inflammation enhanced by dsRNA was partly abolished in the absence of IFN-gamma or IL-17 gene expression, whereas unaffected in the absence of IL-13. In terms of the roles of NOSs, dsRNA-enhanced neutrophilic inflammation was significantly decreased in inducible NOS (iNOS)-deficient mice compared to wild type controls; in addition, this phenotype was inhibited by treatment with a non-specific NOS inhibitor (L-NAME) or an specific inhibitor (1400 W), but not with a specific endothelial NOS inhibitor (AP-CAV peptide). Taken together, these findings suggest that iNOS pathway is important in the development of virus-associated exacerbation of neutrophilic inflammation, which is dependent on both Th1 and Th17 cell responses.