Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 696
Filter
1.
Medicina (B.Aires) ; 81(3): 421-426, jun. 2021. graf
Article in Spanish | LILACS | ID: biblio-1346479

ABSTRACT

Resumen Los virus ARN, excepto los retrovirus, se replican por acción de una ARN polimerasa ARN-dependiente que carece de exonucleasa correctora y, en consecuencia, en cada replicación puede co meter errores. Así se originan mutantes que, según su menor o mayor fitness, se extinguen o bien prosperan y originan variantes que escapan al sistema inmune. Las mutaciones de SARS-CoV-2 más importantes son las que alteran la proteína viral S, porque ella tiene la llave de ingreso del virus a la célula humana. Cuanto más se replican los virus, más mutan, y se hace más probable que aparezcan variantes resistentes dominantes. En esos casos, se requerirá una aplicación más estricta de las medidas de protección de la comunidad. Las vacunas y los anticuerpos policlonales, que inducen una respuesta dirigida hacia toda la proteína S, mantendrían protec ción efectiva contra las variantes del SARS-CoV-2. Además, las vacunas inducirían una mayor respuesta de células T helper y citotóxicas, lo que puede ser un biomarcador de protección. En áreas densamente pobladas con escasas medidas de protección, el virus se difunde libremente y aumenta la probabilidad de mutaciones de escape. India y Manaos ejemplifican esa situación. La evolución natural selecciona las mutantes que se repro ducen con mayor eficiencia sin eliminar al huésped, lo que facilita la propagación. En cambio, la circulación de virus de alta virulencia y letalidad (Ebola, hantavirus), que eliminan al huésped, se circunscribe a determinadas áreas geográficas, sin mayor difusión. Por lo tanto, sería esperable que SARS-CoV-2 evolucione a variantes más infecciosas y menos virulentas.


Abstract RNA viruses (except retroviruses) replicate by the action of an RNA-dependent RNA polymerase, which lacks a proofreading exo nuclease and, consequently, errors may occur in each replication giving place to viral mutants. Depending on their fitness, these mutants either become extinct or thrive, spawning variants that escape the immune system. The most important SARS-CoV-2 mutations are those that alter the amino acid sequence in the viral S protein because this protein holds the key for the virus to enter the human cell. The more viruses replicate, the more they mutate, and the more likely it is that dominant resistant variants will appear. In such cases, more stringent measures for community protection will be required. Vaccines and polyclonal antibodies, which induce a response directed towards several sites along the S protein, would maintain effective protection against SARS-CoV-2 vari ants. Furthermore, vaccines appear to induce an increased helper and cytotoxic T-cell response, which may also be a biomarker of protection. In densely populated areas with insufficient protection measures, the virus spreads freely, thus increasing the likelihood of generating escape mutants. India and Manaus exemplify this situation. Natural evolution selects the mutants that multiply most efficiently without eliminating the host, thus facilitating their spread. Contrastingly, the circulation of viruses of high virulence and lethality (Ebola, hantavirus) that elimi nate the host remain limited to certain geographic areas, without further dissemination. Therefore, it would be expected that SARS-CoV-2 will evolve into more infectious and less virulent variants.


Subject(s)
Humans , Vaccines , COVID-19 , Virus Replication , SARS-CoV-2
2.
Chinese Medical Journal ; (24): 1160-1167, 2021.
Article in English | WPRIM | ID: wpr-878100

ABSTRACT

BACKGROUND@#Hepatitis B core-related antigen (HBcrAg) is a promising disease-monitoring marker for chronic hepatitis B (CHB). We investigated correlations between HBcrAg with antiviral efficacy and virological and histological variables.@*METHODS@#One hundred and forty-five CHB patients from the mainland of China between August 2013 and September 2016 who underwent liver biopsy received entecavir therapy and had paired liver biopsy at 78 weeks. We analyzed correlations between HBcrAg and virological and histological variables in hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients. We also explored the predictors of HBeAg loss after 78 weeks of antiviral therapy. Pearson correlation analysis and logistic forward stepwise regression were the main statistic methods.@*RESULTS@#HBeAg-positive patients (n = 93) had higher baseline HBcrAg (median 7.4 vs. 5.3 log10 U/mL P < 0.001) and greater HBcrAg declines (median 1.6 vs. 0.9 log10 U/mL P = 0.007) than HBeAg-negative patients after 78 weeks of therapy. At baseline, HBcrAg correlated with hepatitis B virus (HBV) DNA in both HBeAg-positive (r = 0.641, P < 0.001) and -negative patients (r = 0.616, P < 0.001), with hepatitis B surface antigen (HBsAg) in HBeAg-positive patients (r = 0.495, P < 0.001), but not with anti-hepatitis B virus core antibody (anti-HBc). Weak correlations existed between HBcrAg, histology activity index (HAI; r = 0.232, P = 0.025), and Ishak fibrosis score (r = -0.292, P = 0.005) in HBeAg-positive patients. At 78 weeks, significant correlations existed only between HBcrAg and anti-HBc in HBeAg-positive (r = -0.263, P = 0.014) and HBeAg-negative patients (r = -0.291, P = 0.045). Decreased HBcrAg significantly correlated with reduced HBV DNA (r = 0.366, P = 0.001; r = 0.626, P < 0.001) and HBsAg (r = 0.526, P = 0.001; r = 0.289, P = 0.044) in HBeAg-positive and -negative patients, respectively, and with reduced HAI in HBeAg-positive patients (r = 0.329, P = 0.001). Patients with HBeAg loss (n = 29) showed a larger reduction in HBcrAg than those without (median 2.3 vs. 1.3 log10 U/mL, P = 0.001). In multivariate analysis, decreased HBcrAg was an independent predictor of HBeAg loss (P = 0.005).@*CONCLUSIONS@#HBcrAg reflects viral replication and protein production. Decreased HBcrAg could predict HBeAg loss after antiviral therapy.@*TRIAL REGISTRATION@#Clinical Trials.gov: NCT01962155; https://www.clinicaltrials.gov/ct2/show/NCT01962155?term=NCT01962155&draw=2&rank=1.


Subject(s)
Antiviral Agents/therapeutic use , Biomarkers , China , DNA, Viral , Hepatitis B Core Antigens/therapeutic use , Hepatitis B Surface Antigens , Hepatitis B e Antigens , Hepatitis B virus/genetics , Hepatitis B, Chronic/drug therapy , Humans , Virus Replication
3.
Rev. Hosp. Clin. Univ. Chile ; 32(2): 107-117, 2021. ilus, tab
Article in Spanish | LILACS | ID: biblio-1290954

ABSTRACT

Covid-19 is an infectious disease whose etiological agent called SARS-CoV-2. It has a high contagion rate, high morbidity and mortality, and potential multi-organ compromise. Its main route of infection is by droplets, however, the infection can be acquired by other routes such as aerosols, fecal-oral and contact with fomites. Although the immune response is essential for defense against any infection, in severe Covid-19 infection, a dysregulation of the immune system occurs, which leads to marked increases of cytokines and the consequent systemic inflammatory state. Inflammation, infection, and viral shedding can compromise the lungs, blood vessels, brain, gastrointestinal (GI) tract, kidneys, heart, and liver, ultimately leading to multiple organ dysfunction and failure. (AU)


Subject(s)
Humans , Male , Female , SARS-CoV-2/pathogenicity , COVID-19/physiopathology , Virus Replication , COVID-19/transmission
4.
Braz. j. med. biol. res ; 54(7): e10240, 2021. tab, graf
Article in English | LILACS | ID: biblio-1249316

ABSTRACT

Dengue is the most important arthropod-borne viral disease worldwide. Infection with any of the four dengue virus (DENV) serotypes can be asymptomatic or lead to disease with clinical symptoms ranging from undifferentiated and self-limiting fever to severe dengue disease, which can be fatal in some cases. Currently, no specific antiviral compound is available for treating DENV. The aim of this study was to identify compounds in plants from Paraguayan folk medicine with inhibitory effects against DENV. We found high virucidal activity (50% maximal effective concentration (EC50) value of 24.97 µg/mL) against DENV-2 in the ethanolic extract of the roots of Solanum sisymbriifolium Lam. (Solanaceae) without an evident cytotoxic effect on Vero E6 cells. Three saponins isolated from the root extract showed virucidal effects (EC50 values ranging from 24.9 to 35.1 µg/mL) against DENV-2. Additionally, the saponins showed inhibitory activity against yellow fever virus (EC50 values ranging from 126 to 302.6 µg/mL), the prototype virus of the Flavivirus genus, suggesting that they may also be effective against other members of this genus. Consequently, these saponins may be lead compounds for the development of antiviral agents.


Subject(s)
Saponins/pharmacology , Solanum , Dengue Virus , Antiviral Agents/pharmacology , Virus Replication , Yellow fever virus
5.
Braz. j. infect. dis ; 24(1): 13-24, Feb. 2020. tab, graf
Article in English | LILACS | ID: biblio-1089334

ABSTRACT

ABSTRACT Dengue has been a significant public health problem in Colombia since the simultaneous circulation of the four dengue virus serotypes. The replicative fitness of dengue is a biological feature important for virus evolution and contributes to elucidating the behavior of virus populations and viral pathogenesis. However, it has not yet been studied in Colombian isolates. This study aimed to compare the replicative fitness of the four dengue virus serotypes and understand the association between the serotypes, their in vitro infection ability, and their replication in target cells. We used three isolates of each DENV serotype to infect Huh-7 cells at an MOI of 0.5. The percentage of infected cells was evaluated by flow cytometry, cell viability was evaluated by MTT assay, and the pathogenicity index was calculated as a ratio of both parameters. The replicative fitness was measured by the number of viral genome copies produced using quantitative PCR and the production of infectious viral progeny was measured by plaque assay. We showed that Huh-7 cells were susceptible to infection with all the different strain isolates. Nevertheless, the biological characteristics, such as infectious ability and cell viability, were strain-dependent. We also found different degrees of pathogenicity between strains of the four serotypes, representative of the heterogeneity displayed in the circulating population. When we analyzed the replicative fitness using the mean values obtained from RT-qPCR and plaque assay for the different strains, we found serotype-dependent behavior. The highest mean values of replicative fitness were obtained for DENV-1 (log 4.9 PFU/ml) and DENV-4 (log 5.28 PFU/ml), followed by DENV-2 (log 3.9 PFU/ml) and DENV-3 (log 4.31 PFU/ml). The internal heterogeneity of the replicative fitness within each serotype could explain the simultaneous circulation of the four DENV serotypes in Colombia.


Subject(s)
Humans , Virus Replication/genetics , Dengue Virus/genetics , Dengue Virus/pathogenicity , Serogroup , Viral Plaque Assay , Reference Values , Tetrazolium Salts , Time Factors , RNA, Viral/genetics , Cell Line , Cell Survival , Cells, Cultured , Colombia , Reverse Transcriptase Polymerase Chain Reaction , Flow Cytometry , Formazans , Liver/cytology
6.
Chinese Journal of Biotechnology ; (12): 1269-1276, 2020.
Article in Chinese | WPRIM | ID: wpr-826850

ABSTRACT

Human adenoviruses are widespread causative agent that induces respiratory diseases, epidemic keratoconjunctivitis and other related diseases. Adenoviruses are commonly used in experimental and clinical areas. It is one of the most commonly used virus vectors in gene therapy, and it has attracted a lot of attention and has a high research potential in tumor gene therapy and virus oncolytic. Here, we summarize the biological characteristics, epidemiology and current application of adenovirus, in order to provide reference for engineering application of adenovirus.


Subject(s)
Adenovirus Infections, Human , Epidemiology , Virology , Adenoviruses, Human , Genetics , Genetic Engineering , Methods , Genetic Vectors , Humans , Oncolytic Virotherapy , Oncolytic Viruses , Genetics , Virus Replication
7.
Protein & Cell ; (12): 723-739, 2020.
Article in English | WPRIM | ID: wpr-828747

ABSTRACT

Emerging and re-emerging RNA viruses occasionally cause epidemics and pandemics worldwide, such as the on-going outbreak of the novel coronavirus SARS-CoV-2. Herein, we identified two potent inhibitors of human DHODH, S312 and S416, with favorable drug-likeness and pharmacokinetic profiles, which all showed broad-spectrum antiviral effects against various RNA viruses, including influenza A virus, Zika virus, Ebola virus, and particularly against SARS-CoV-2. Notably, S416 is reported to be the most potent inhibitor so far with an EC of 17 nmol/L and an SI value of 10,505.88 in infected cells. Our results are the first to validate that DHODH is an attractive host target through high antiviral efficacy in vivo and low virus replication in DHODH knock-out cells. This work demonstrates that both S312/S416 and old drugs (Leflunomide/Teriflunomide) with dual actions of antiviral and immuno-regulation may have clinical potentials to cure SARS-CoV-2 or other RNA viruses circulating worldwide, no matter such viruses are mutated or not.


Subject(s)
Animals , Antiviral Agents , Pharmacology , Therapeutic Uses , Betacoronavirus , Physiology , Binding Sites , Cell Line , Coronavirus Infections , Drug Therapy , Virology , Crotonates , Pharmacology , Cytokine Release Syndrome , Drug Therapy , Drug Evaluation, Preclinical , Gene Knockout Techniques , Humans , Influenza A virus , Leflunomide , Pharmacology , Mice , Mice, Inbred BALB C , Orthomyxoviridae Infections , Drug Therapy , Oseltamivir , Therapeutic Uses , Oxidoreductases , Metabolism , Pandemics , Pneumonia, Viral , Drug Therapy , Virology , Protein Binding , Pyrimidines , RNA Viruses , Physiology , Structure-Activity Relationship , Toluidines , Pharmacology , Ubiquinone , Metabolism , Virus Replication
8.
Protein & Cell ; (12): 723-739, 2020.
Article in English | WPRIM | ID: wpr-828583

ABSTRACT

Emerging and re-emerging RNA viruses occasionally cause epidemics and pandemics worldwide, such as the on-going outbreak of the novel coronavirus SARS-CoV-2. Herein, we identified two potent inhibitors of human DHODH, S312 and S416, with favorable drug-likeness and pharmacokinetic profiles, which all showed broad-spectrum antiviral effects against various RNA viruses, including influenza A virus, Zika virus, Ebola virus, and particularly against SARS-CoV-2. Notably, S416 is reported to be the most potent inhibitor so far with an EC of 17 nmol/L and an SI value of 10,505.88 in infected cells. Our results are the first to validate that DHODH is an attractive host target through high antiviral efficacy in vivo and low virus replication in DHODH knock-out cells. This work demonstrates that both S312/S416 and old drugs (Leflunomide/Teriflunomide) with dual actions of antiviral and immuno-regulation may have clinical potentials to cure SARS-CoV-2 or other RNA viruses circulating worldwide, no matter such viruses are mutated or not.


Subject(s)
Animals , Antiviral Agents , Pharmacology , Therapeutic Uses , Betacoronavirus , Physiology , Binding Sites , Cell Line , Coronavirus Infections , Drug Therapy , Virology , Crotonates , Pharmacology , Cytokine Release Syndrome , Drug Therapy , Drug Evaluation, Preclinical , Gene Knockout Techniques , Humans , Influenza A virus , Leflunomide , Pharmacology , Mice , Mice, Inbred BALB C , Orthomyxoviridae Infections , Drug Therapy , Oseltamivir , Therapeutic Uses , Oxidoreductases , Metabolism , Pandemics , Pneumonia, Viral , Drug Therapy , Virology , Protein Binding , Pyrimidines , RNA Viruses , Physiology , Structure-Activity Relationship , Toluidines , Pharmacology , Ubiquinone , Metabolism , Virus Replication
9.
Article in Chinese | WPRIM | ID: wpr-828561

ABSTRACT

The three known human highly pathogenic coronaviruses are severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus, (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Human highly pathogenic coronaviruses are composed of non-structural proteins, structural proteins and accessory proteins. Viral particles recognize host receptors via spike glycoprotein (S protein), enter host cells by membrane fusion, replicate in host cells through large replication-transcription complexes, and promote proliferation by interfering with and suppressing the host's immune response. Human highly pathogenic coronaviruses are hosted by humans and vertebrates. Viral particles are transmitted through droplets, contact and aerosols or likely through digestive tract, urine, eyes and other routes. This review discusses the mechanisms of proliferation and transmission of highly pathogenic human coronaviruses based on the results of existing research, providing basis for future study on interrupting the transmission and pathogenicity of human highly pathogenic coronaviruses.


Subject(s)
Animals , Betacoronavirus , Physiology , Coronavirus Infections , Allergy and Immunology , Virology , Humans , Middle East Respiratory Syndrome Coronavirus , Physiology , Pandemics , Pneumonia, Viral , Allergy and Immunology , Virology , SARS Virus , Physiology , Virus Replication , Physiology
10.
Protein & Cell ; (12): 723-739, 2020.
Article in English | WPRIM | ID: wpr-827018

ABSTRACT

Emerging and re-emerging RNA viruses occasionally cause epidemics and pandemics worldwide, such as the on-going outbreak of the novel coronavirus SARS-CoV-2. Herein, we identified two potent inhibitors of human DHODH, S312 and S416, with favorable drug-likeness and pharmacokinetic profiles, which all showed broad-spectrum antiviral effects against various RNA viruses, including influenza A virus, Zika virus, Ebola virus, and particularly against SARS-CoV-2. Notably, S416 is reported to be the most potent inhibitor so far with an EC of 17 nmol/L and an SI value of 10,505.88 in infected cells. Our results are the first to validate that DHODH is an attractive host target through high antiviral efficacy in vivo and low virus replication in DHODH knock-out cells. This work demonstrates that both S312/S416 and old drugs (Leflunomide/Teriflunomide) with dual actions of antiviral and immuno-regulation may have clinical potentials to cure SARS-CoV-2 or other RNA viruses circulating worldwide, no matter such viruses are mutated or not.


Subject(s)
Animals , Antiviral Agents , Pharmacology , Therapeutic Uses , Betacoronavirus , Physiology , Binding Sites , Cell Line , Coronavirus Infections , Drug Therapy , Virology , Crotonates , Pharmacology , Cytokine Release Syndrome , Drug Therapy , Drug Evaluation, Preclinical , Gene Knockout Techniques , Humans , Influenza A virus , Leflunomide , Pharmacology , Mice , Mice, Inbred BALB C , Orthomyxoviridae Infections , Drug Therapy , Oseltamivir , Therapeutic Uses , Oxidoreductases , Metabolism , Pandemics , Pneumonia, Viral , Drug Therapy , Virology , Protein Binding , Pyrimidines , RNA Viruses , Physiology , Structure-Activity Relationship , Toluidines , Pharmacology , Ubiquinone , Metabolism , Virus Replication
11.
Chinese Journal of Biotechnology ; (12): 605-611, 2020.
Article in Chinese | WPRIM | ID: wpr-827008

ABSTRACT

Cyclophilin A (CypA) is a widely distributed and highly conserved protein in organisms. It has peptidyl-prolyl cis/trans isomerase activity and is a receptor for cyclosporin A (CsA). Coronaviruses are enveloped, single-stranded, positive-sense RNA viruses. Seven types of coronaviruses are currently known to infect humans, among which SARS-CoV, MERS-CoV, and SARS-CoV-2 are fatal for humans. It is well established that CypA is essential for the replication of various coronaviruses such as SARS-CoV, CoV-229E, CoV-NL63, and FCoV. Additionally, CsA and its derivatives (ALV, NIM811, etc.) have obvious inhibitory effects on a variety of coronaviruses. These results suggest that CypA is a potential antiviral target and the existing drug CsA might be used as an anti-coronavirus drug. At the end of 2019, SARS-CoV-2 raged in China, which seriously theatern human health and causes huge economic lases. In view of this, we describe the effects of CypA on the replication of coronaviruses and the antiviral activities of its inhibitors, which will provide the scientific basis and ideas for the development of antiviral drugs for SARS-CoV-2.


Subject(s)
Antiviral Agents , Pharmacology , Therapeutic Uses , Betacoronavirus , Coronavirus , Coronavirus Infections , Drug Therapy , Epidemiology , Virology , Cyclophilin A , Cyclosporine , Chemistry , Pharmacology , Therapeutic Uses , Humans , Pandemics , Pneumonia, Viral , Drug Therapy , Epidemiology , Virology , SARS Virus , Virus Replication
12.
Chinese Journal of Biotechnology ; (12): 879-890, 2020.
Article in Chinese | WPRIM | ID: wpr-826888

ABSTRACT

Human parvovirus B19 (B19 virus) is one of the two parvoviruses that cause human diseases. As an important pathogen to humans, it causes infectious erythema in children, acute aplastic anemia, fetal edema and death. In this review, we focus on the recent advances in the molecular virology of B19V, such as viral genotypes, viral receptor, genomic features and viral replication, viral transcription and post-transcription regulation, viral nonstructural and structural protein features and functions, viral diagnosis and antiviral agents, to provide reference for further study of B19 pathogenesis mechanisms, treatment and diagnostic strategies.


Subject(s)
Antiviral Agents , DNA, Viral , Genetics , Erythema Infectiosum , Diagnosis , Virology , Genotype , Humans , Parvovirus B19, Human , Genetics , Virology , Virus Replication
13.
Chinese Journal of Biotechnology ; (12): 1961-1969, 2020.
Article in Chinese | WPRIM | ID: wpr-878457

ABSTRACT

Coronaviruses are a type of positive-sense single-stranded RNA virus with envelope and widely exist in nature to cause respiratory infectious diseases. The novel coronavirus is a new outbreak virus that is susceptible to all people. Up to now, the disease has been widely spread in the world and poses a great threat to public health. In this review, the genomic features, key proteins, host infection and replication of coronaviruses and novel coronaviruses are reviewed in order to provide theoretical basis for the study of the pathogenic mechanism of virus infection on host cells and to provide basic support for the development of specific antiviral drugs.


Subject(s)
Betacoronavirus/physiology , COVID-19 , Coronavirus Infections/virology , Humans , Pandemics , Pneumonia, Viral/virology , SARS-CoV-2 , Virus Replication
14.
Chinese Medical Journal ; (24): 2867-2873, 2020.
Article in English | WPRIM | ID: wpr-877943

ABSTRACT

Antiretroviral therapy (ART) can effectively inhibit human immunodeficiency virus-1 (HIV-1) replication, but is not curative due to the existence of a stable viral latent reservoir harboring replication-competent proviruses. In order to reduce or eliminate the HIV-1 latent reservoir, characteristics of the latently infected cells need to be intensively studied, and a comprehensive understanding of the heterogenous nature of the latent reservoir will be critical to develop novel therapeutic strategies. Here, we discuss the different cell types and mechanisms contributing to the complexity and heterogeneity of HIV-1 latent reservoirs, and summarize the key challenges to the development of cure strategies for acquired immunodeficiency syndrome (AIDS).


Subject(s)
CD4-Positive T-Lymphocytes , HIV Infections/drug therapy , HIV-1 , Humans , Viral Load , Virus Latency , Virus Replication
15.
Mem. Inst. Oswaldo Cruz ; 115: e190357, 2020. graf
Article in English | LILACS | ID: biblio-1091235

ABSTRACT

BACKGROUND Viruses can modulate intracellular signalling pathways to complete their infectious cycle. Among these, the PI3K/Akt pathway allows prolonged survival of infected cells that favours viral replication. GSK3β, a protein kinase downstream of PI3K/Akt, gets inactivated upon activation of the PI3K/Akt pathway, and its association with viral infections has been recently established. In this study, the role of GSK3β during Dengue virus-2 (DENV-2) infection was investigated. METHODS GSK3β participation in the DENV-2 replication process was evaluated with pharmacological and genetic inhibition during early [0-12 h post-infection (hpi)], late (12-24 hpi), and 24 hpi in Huh7 and Vero cells. We assessed the viral and cellular processes by calculating the viral titre in the supernatants, In-Cell Western, western blotting and fluorescence microscopy. RESULTS Phosphorylation of GSK3β-Ser9 was observed at the early stages of infection; neither did treatment with small molecule inhibitors nor pre-treatment prior to viral infection of GSK3β reduce viral titres of the supernatant at these time points. However, a decrease in viral titres was observed in cells infected and treated with the inhibitors much later during viral infection. Consistently, the infected cells at this stage displayed plasma membrane damage. Nonetheless, these effects were not elicited with the use of genetic inhibitors of GSK3β. CONCLUSIONS The results suggest that GSK3β participates at the late stages of the DENV replication cycle, where viral activation may promote apoptosis and release of viral particles.


Subject(s)
Animals , Virus Replication/physiology , Dengue Virus/enzymology , Glycogen Synthase Kinases/antagonists & inhibitors , Glycogen Synthase Kinases/physiology , Phosphorylation/physiology , Signal Transduction , Blotting, Western , Apoptosis/physiology , Aedes/cytology , Cell Line, Tumor , Microscopy, Fluorescence
16.
Clin. biomed. res ; 40(2)2020. ilus
Article in English | LILACS | ID: biblio-1148189

ABSTRACT

Introduction: Human immunodeficiency virus (HIV), which causes Acquired Immunodeficiency Syndrome, still affects millions of people worldwide. Despite recent advances in the understanding of biological mechanisms of viral replication, there are relevant gaps regarding the virus-host relationship. Unraveling these complexities may lead to the development of new therapeutic strategies and the establishment of new biomarkers useful for the diagnosis and prognosis of infection and its comorbidities. Therefore, in this study we discuss the main biological characteristics of microRNAs and the potential use of these nucleic acids in their free circulating form as indicators of risk or protection against HIV infection. Methods: A narrative review of the literature was carried out in the following databases through keyword and/or health descriptor searches: i) Google Scholar; ii) CAPES periodicals portal; iii) United States National Library of Medicine (PubMed) and iv) Elsevier's Science Direct library. The keywords "microRNA; HIV infection; circulating microRNA; biomarkers" were used to search the databases as mentioned above.Results: Circulating microRNAs (ci-miRNA) are closely related to numerous processes in the HIV infection pathophysiology. They are involved in viral latency, increased viremia, hepatic injury, heart dysfunction, pulmonary hypertension, immune response impairment, and participate in Kaposi's sarcoma pathology. Additionally, these molecules may indicate protection in elite controllers, reduce viral replication and load, and be useful markers of the infection's eclipse phase. Conclusion: Ci-miRNA levels are altered levels in individuals with HIV, playing a dual role in infection. Advances in research have shown that ci-miRNAs could differentiate stages of HIV infection and diseases associated with a viral infection and serve as biomarkers for antiretroviral therapy's effectiveness through changes in their expression. (AU)


Subject(s)
Humans , HIV Infections/diagnosis , MicroRNAs , Virus Replication/immunology , Biomarkers
17.
Article in English | WPRIM | ID: wpr-758953

ABSTRACT

Viral-encoded microRNAs (miRNAs) have vital roles in the regulation of virus replications and host immune responses. The results of previous studies have indicated that miRNA clusters are involved in the replication and virulence of the pseudorabies virus (PRV), which may potentially lead to immune escape or facilitation of PRV replication. This study's previous research revealed that prv-miR-LLT11a was differentially expressed during PRV infection. The present study's results have demonstrated that prv-miR-LLT11a could significantly inhibit PRV replication. It was further determined that SLA-1 was the target gene of prv-miR-LLT11a, and simultaneously, that overexpression of prv-miR-LLT11a could downregulate the mRNA and protein levels of SLA-1 in a dose-independent manner. Furthermore, the present study also observed that prv-miR-LLT11a can downregulate TAP1 expression. Our findings provide a better understanding of the molecular mechanism involved in the effects of prv-miR-LLT11a on SLA-1 and TAP1 as well as its involvement in immune system evasion of PRV.


Subject(s)
Herpesvirus 1, Suid , Immune System , MicroRNAs , Pseudorabies , RNA, Messenger , United Nations , Virulence , Virus Replication
18.
Article in Chinese | WPRIM | ID: wpr-772111

ABSTRACT

OBJECTIVE@#To analyze the characteristics of BK polymavirus (BKV) infection and the optimal time window for intervention in kidney transplant recipients (KTRs).@*METHODS@#We retrospectively analyzed the clinical data and treatment regimens in 226 KTRs in our center between January, 2013 and January, 2018. Among the recipients, 157 had a urine BKV load ≥1.0×10 copy/mL after transplantation, and 69 had a urine BKV load below 1.0×10 copy/mL (control group).@*RESULTS@#Among the 157 KTRs, 60 (38.2%) recipients were positive for urine BKV, 66 (42.0%) had BKV viruria, and 31(19.7%) had BKV viremia. The incidence of positive urine occult blood was significantly higher in BKV-positive recipients than in the control group ( < 0.05). The change of urine BKV load was linearly related to that of Tacrolimus trough blood level (=0.351, < 0.05). In urine BKV positive group, the average estimated glomerular filtration rate (eGFR) was below the baseline level (60 mL·min·1.73 m) upon diagnosis of BKV infection reactivation, and recovered the normal level after intervention. In patients with BKV viruria and viremia, the average eGFR failed to return to the baseline level in spite of improvement of the renal function after intervention.@*CONCLUSIONS@#Positive urine occult blood after transplantation may be associated with BKV infection reactivation in some of the KTRs. BKV infection is sensitive to changes of plasma concentration of immunosuppressive agents. Early intervention of BKV replication in KTRs with appropriate dose reduction for immunosuppression can help to control virus replication and stabilize the allograft function.


Subject(s)
BK Virus , Physiology , Humans , Kidney Transplantation , Polyomavirus Infections , Virology , Retrospective Studies , Transplant Recipients , Tumor Virus Infections , Virology , Viral Load , Virus Replication
19.
Chinese Journal of Biotechnology ; (12): 1029-1040, 2019.
Article in Chinese | WPRIM | ID: wpr-771825

ABSTRACT

To evaluate the optimal administration frequency for interferon-α (IFN-α) and the effect of its combined use with inactive virus on chicken flocks, the prokaryotic expression plasmid pET-22b-ChIFN-α was constructed and transferred into Escherichia coli BL21(DE3) host bacteria to induce the expression of chicken IFN-α and to harvest recombinant proteins inclusion bodies. The expression of recombinant chicken IFN-α was confirmed by SDS-PAGE, and the results demonstrated that the chicken IFN-α (20 kDa) was highly expressed using the prokaryotic expression vector with a concentration of 0.2 mg/mL in the medium. Chicken IFN-α was diluted to 2.5×10⁴ U/fowls and administered to immunized specific-pathogen-free chickens orally in combination with inactivated H9N2 subtype influenza virus. Chicken that received chicken IFN-α were safe after three repeated immunizations (96 h). In addition, chicken IFN-α could induce higher levels of antiviral-related inducible genes in peripheral blood, spleen, and thymus of chicken flocks. The results of a challenge assay revealed that the lowest detoxification rates of chicken IFN-α ranged from three to five days, suggesting a higher capacity to resist H9N2 subtype avian influenza virus. The present study obtained the optimal immune frequency and immunization period for chicken IFN-α to provide theoretical support for the optimal clinical application of IFN-α.


Subject(s)
Administration, Oral , Animals , Chickens , Humans , Influenza A Virus, H9N2 Subtype , Interferon-alpha , Virus Replication
20.
Chinese Journal of Biotechnology ; (12): 1126-1134, 2019.
Article in Chinese | WPRIM | ID: wpr-771815

ABSTRACT

Human bocavirus 1 (HBoV1) non-structural protein NS1 is a multifunctional protein important for virus replication and induction of apoptosis in host cell. To better understand the function of the NS1 protein, it is urgent to address reducing the toxicity of NS1 to host cells. In the present study, we established a stable cell line that regulates expression of NS1 of HBoV1. The recombinant lentivirus plasmid containing a regulatable promoter fused with ns1 gene was constructed and transfected into HEK 293T cells using transfection reagent. The HEK 293T cell lines stably expressing NS1-100 and NS1-70 proteins were established by screening resistant cells with puromycin and inducing NS1 expression with doxycycline. The expression of NS1 protein was determined by fluorescent labeling protein and Western blotting. HBoV1 promoter was transfected into stably expressing NS1 cell line and its trans-transcriptional activity was analyzed. The results showed that NS1 protein was expressed stably in the established cell lines and had a strong activation activity on the HBoV1 promoter driving luciferase gene. Taken together, this study provides a solid basis for further research on the function of NS1 and the pathogenesis of human bocavirus.


Subject(s)
Human bocavirus , Promoter Regions, Genetic , Transcriptional Activation , Viral Nonstructural Proteins , Virus Replication
SELECTION OF CITATIONS
SEARCH DETAIL