RESUMO
Knowledge of Human Polyomavirus (HPyV) infection in the anal area and its association with sexually transmitted infections such as Human Papillomavirus (HPV) and Human Immunodeficiency Virus (HIV) remains limited. Therefore, anal specimens from 150 individuals of both sexes were analyzed for screening purposes. HPV DNA was found in 50.7% of cases, with a predominance of high-risk (HR) genotypes. HPyV DNA was found in 39.3% of samples, with Merkel Cell Polyomavirus (MCPyV) being the most common, with a higher viral load than JCPyV and BKPyV. In addition, MCPyV viral load increased in people living with HIV (PLWH) with HPV infection (p < 0.0001).
Assuntos
Coinfecção , Infecções por HIV , Poliomavírus das Células de Merkel , Infecções por Papillomavirus , Infecções por Polyomavirus , Carga Viral , Humanos , Masculino , Feminino , Infecções por HIV/virologia , Infecções por HIV/complicações , Infecções por Papillomavirus/virologia , Adulto , Pessoa de Meia-Idade , Coinfecção/virologia , Coinfecção/epidemiologia , Poliomavírus das Células de Merkel/genética , Poliomavírus das Células de Merkel/isolamento & purificação , Infecções por Polyomavirus/virologia , Infecções por Polyomavirus/epidemiologia , DNA Viral/genética , Genótipo , Canal Anal/virologia , Canal Anal/patologia , Idoso , Adulto Jovem , Papillomaviridae/genética , Papillomaviridae/isolamento & purificação , Papillomaviridae/classificação , Infecções Tumorais por Vírus/virologia , Infecções Tumorais por Vírus/epidemiologia , PrevalênciaRESUMO
Due to its peculiar histopathological findings, pleomorphic xanthoastrocytoma (PXA), a rare cerebral tumor of young adults with a slow growth and a good prognosis, resembles to the lytic phase of progressive multifocal leukoencephalopathy, a fatal neurodegenerative disease caused by JC polyomavirus (JCPyV). Therefore, the presence of JCPyV DNA was examined in an 11-year-old child with xanthoastrocytoma, WHO grade 3, by quantitative PCR (qPCR) and nested PCR (nPCR) using primers amplifying sequences encoding the N- and C-terminal region of large T antigen (LTAg), the non-coding control region (NCCR), and viral protein 1 (VP1) DNA. The expression of transcripts from LTAg and VP1 genes was also evaluated. In addition, viral microRNAs' (miRNAs) expression was investigated. Cellular p53 was also searched at both DNA and RNA level. qPCR revealed the presence of JCPyV DNA with a mean value of 6.0 × 104 gEq/mL. nPCR gave a positive result for the 5' region of the LTAg gene and the NCCR, whereas 3' end LTAg and VP1 DNA sequences were not amplifiable. Only LTAg transcripts of 5' end were found whereas VP1 gene transcript was undetectable. Although in most cases, either Mad-1 or Mad-4 NCCRs have been identified in association with JCPyV-positive human brain neoplasms, the archetype NCCR structure was observed in the patient's sample. Neither viral miRNA miR-J1-5p nor p53 DNA and RNA were detected. Although the expression of LTAg supports the possible role of JCPyV in PXA, further studies are warranted to better understand whether the genesis of xanthoastrocytoma could depend on the transformation capacity of LTAg by Rb sequestration.
Assuntos
Vírus JC , Leucoencefalopatia Multifocal Progressiva , MicroRNAs , Doenças Neurodegenerativas , Adulto Jovem , Humanos , Criança , Sequência de Bases , Doenças Neurodegenerativas/genética , Proteína Supressora de Tumor p53/genética , Vírus JC/genética , MicroRNAs/genética , Antígenos Virais de Tumores/genética , DNA Viral/genéticaRESUMO
Merkel cell polyomavirus (MCPyV) is the major cause of Merkel cell carcinoma (MCC), an aggressive skin cancer. MCPyV large T-antigen (LTag) and small T-antigen (sTag) are the main oncoproteins involved in MCPyV-induced MCC. A hallmark of MCPyV-positive MCC cells is the expression of a C-terminal truncated LTag. Protein kinase A (PKA) plays a fundamental role in a variety of biological processes, including transcription by phosphorylating and thereby regulating the activity of transcription factors. As MCPyV LTag has been shown to be phosphorylated and acts as a transcription factor for the viral early and late promoter, we investigated whether LTag can be phosphorylayted by PKA, and whether this affects the transcript activity of LTag. Using a phosphorylation prediction algorithm, serine 191, 203, and 265 were identified as putative phosphorylation sites for PKA. Mass spectrometry of in vitro PKA-phosphorylated peptides confirmed phosphorylation of S203 and S265, but not S191. Full-length LTag inhibited early and late promoter activity of MCPyV, whereas the truncated MKL2 LTag variant stimulated both promoters. Single non-phosphorylable, as well as phosphomimicking mutations did not alter the inhibitory effect of full-length LTag. However, the non-phosphorylable mutations abrogated transactivation of the MCPyV promoters by MKL2 LTag, whereas phosphomimicking substitutions restored the ability of MKL2 LTag to activate the promoters. Triple LTag and MKL2 LTag mutants had the same effect as the single mutants. Activation of the PKA signaling pathway did not enhance MCPyV promoter activity, nor did it affect LTag expression levels in MCPyV-positive Merkel cell carcinoma (MCC) cells. Our results show that phosphorylation of truncated LTag stimulates viral promoter activity, which may contribute to higher levels of the viral oncoproteins LTag and sTag. Interfering with PKA-induced LTag phosphorylation/activity may be a therapeutic strategy to treat MCPyV-positive MCC patients.
Assuntos
Antígenos Transformantes de Poliomavirus , Carcinoma de Célula de Merkel , Poliomavírus das Células de Merkel , Infecções por Polyomavirus , Neoplasias Cutâneas , Infecções Tumorais por Vírus , Humanos , Carcinoma de Célula de Merkel/metabolismo , Carcinoma de Célula de Merkel/virologia , Proteínas Quinases Dependentes de AMP Cíclico/genética , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Poliomavírus das Células de Merkel/metabolismo , Fosforilação , Infecções por Polyomavirus/metabolismo , Infecções por Polyomavirus/virologia , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/virologia , Infecções Tumorais por Vírus/metabolismo , Infecções Tumorais por Vírus/virologia , Antígenos Transformantes de Poliomavirus/metabolismo , Transcrição GênicaRESUMO
Merkel cell polyomavirus (MCPyV) has been detected in respiratory specimens including those from Cystic Fibrosis (CF) patients, raising questions about its immunological and clinical relevance in the respiratory tract. MCPyV might promote an inappropriate antiviral response contributing to a chronic inflammatory response and resulting in detrimental effects in CF. Respiratory samples (n = 1138) were randomly collected from respiratory tract of CF patients (n = 539) during July 2018-October 2019. MCPyV-DNA detection was performed by real time PCR and positive samples were characterized by sequencing of the NCCR genomic region. The transcript levels of Toll-like receptor 9 (TLR9) and type I interferon (IFN-I) genes (IFNα, IFNß and IFNε) were examined by real-time RT-PCR assays. MCPyV-DNA was detected in 268 out of 1138 respiratory specimens (23.5%) without any difference in the prevalence of MCPyV-DNA according to age, gender or bacteriological status of CF individuals. Thirteen out of 137 CF patients remained positive for MCPyV-DNA over the time (a median follow-up period of 8.8 months). Detection of MCPyV-DNA in respiratory specimens was not associated with the occurrence of exacerbation events. Both MCPyV positive adolescents (11-24 years) and adults (≥25 years) had lower mRNA levels of TLR9, IFNß, IFNε and IFNα than the negative patients of the same age group, while MCPyV positive children produced increased levels of TLR9 and IFN-I genes (p < 0.05 for TLR9, IFNß, IFNε) with respect to the negative ones. There were significant differences in TLR9 levels (p < 0.01), but not in those of IFNs, between MCPyV-DNA positive and negative patients with S. aureus, P. aeruginosa or both. Overall, these results indicate that MCPyV-DNA is frequently detected in the respiratory samples of CF patients and might influence the expression levels of IFN-related genes in an age dependent manner. The concomitant detection of MCPyV together with S. aureus and/or P. aeruginosa correlated with alterations in TLR9 levels suggesting that virus-bacteria coinfections might contribute to affect antiviral immunity in CF patients.
Assuntos
Fibrose Cística , Poliomavírus das Células de Merkel , Infecções por Polyomavirus , Adolescente , Adulto , Antivirais , Criança , Fibrose Cística/complicações , DNA Viral/análise , DNA Viral/genética , Humanos , Poliomavírus das Células de Merkel/genética , Infecções por Polyomavirus/epidemiologia , Prevalência , Pseudomonas aeruginosa/genética , Staphylococcus aureus/genética , Receptor Toll-Like 9/genéticaRESUMO
Herpes simplex virus type-1 (HSV-1) and John Cunningham polyomavirus (JCPyV) are widely distributed DNA viruses causing mainly asymptomatic infection, but also mild to very severe diseases, especially when these viruses reach the brain. Some drugs have been developed to inhibit HSV-1 replication in host cells, but their prolonged use may induce resistance phenomena. In contrast, to date, there is no cure for JCPyV. The search for alternative drugs that can reduce viral infections without undermining the host cell is moving toward antimicrobial peptides (AMPs) of natural occurrence. These include amphibian AMPs belonging to the temporin family. Herein, we focus on temporin G (TG), showing that it strongly affects HSV-1 replication by acting either during the earliest stages of its life cycle or directly on the virion. Computational studies have revealed the ability of TG to interact with HSV-1 glycoprotein B. We also found that TG reduced JCPyV infection, probably affecting both the earliest phases of its life cycle and the viral particle, likely through an interaction with the viral capsid protein VP1. Overall, our results are promising for the development of short naturally occurring peptides as antiviral agents used to counteract diseases related to HSV-1 and JCPyV.
Assuntos
Herpesvirus Humano 1 , Anfíbios , Animais , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos , Herpesvirus Humano 1/fisiologia , Replicação ViralRESUMO
Italy was one of the most affected nations by coronavirus disease 2019 outside China. The infections, initially limited to Northern Italy, spread to all other Italian regions. This study aims to provide a snapshot of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) epidemiology based on a single-center laboratory experience in Rome. The study retrospectively included 6565 subjects tested for SARS-CoV-2 at the Laboratory of Virology of Sapienza University Hospital in Rome from 6 March to 4 May. A total of 9995 clinical specimens were analyzed, including nasopharyngeal swabs, bronchoalveolar lavage fluids, gargle lavages, stools, pleural fluids, and cerebrospinal fluids. Positivity to SARS-CoV-2 was detected in 8% (527/6565) of individuals, increased with age, and was higher in male patients (P < .001). The number of new confirmed cases reached a peak on 18 March and then decreased. The virus was detected in respiratory samples, in stool and in pleural fluids, while none of gargle lavage or cerebrospinal fluid samples gave a positive result. This analysis allowed to gather comprehensive information on SARS-CoV-2 epidemiology in our area, highlighting positivity variations over time and in different sex and age group and the need for a continuous surveillance of the infection, mostly because the pandemic evolution remains unknown.
Assuntos
COVID-19 , Pandemias , SARS-CoV-2/patogenicidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Líquido da Lavagem Broncoalveolar/virologia , COVID-19/diagnóstico , COVID-19/epidemiologia , Teste para COVID-19 , Criança , Pré-Escolar , Fezes/virologia , Feminino , Hospitais Universitários , Humanos , Lactente , Recém-Nascido , Laboratórios , Masculino , Pessoa de Meia-Idade , Nasofaringe/virologia , Derrame Pleural/virologia , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Cidade de Roma/epidemiologia , SARS-CoV-2/genética , Índice de Gravidade de DoençaRESUMO
BACKGROUND: Human polyomavirus 6 (HPyV6) and HPyV7 are two of the novel polyomaviruses that were originally detected in non-diseased skin. Serological studies have shown that these viruses are ubiquitous in the healthy adult population with seroprevalence up to 88% for HPyV6 and 72% for HPyV7. Both viruses are associated with pruritic skin eruption in immunocompromised patients, but a role with other diseases in immunoincompetent patients or malignancies has not been established. METHODS: PCR was used to determine the presence of HPyV6 and HPyV7 DNA in urine samples from systemic lupus erythematosus (n = 73), multiple sclerosis (n = 50), psoriasis vulgaris (n = 15), arthritic psoriasis (n = 15) and HIV-positive patients (n = 66). In addition, urine from pregnant women (n = 47) and healthy blood donors (n = 20) was investigated. RESULTS: HPyV6 DNA was detected in 21 (28.8%) of the urine specimens from SLE patients, in 6 (9.1%) of the urine samples from the HIV-positive cohort, and in 19 (40.4%) samples from pregnant women. HPyV7 DNA was only found in 6 (8.2%) of the urine specimens from SLE patients and in 4 (8.5%) samples from pregnant women. No HPyV6 and HPyV7 viruria was detected in the urine samples from the other patients. CONCLUSIONS: HPyV6, and to a lesser extend HPyV7, viruria seems to be common in SLE and HIV-positive patients, and pregnant women. Whether these viruses are of clinical relevance in these patients is not known.
Assuntos
DNA Viral/urina , Hospedeiro Imunocomprometido , Polyomaviridae/genética , Infecções por Polyomavirus/urina , Adulto , Estudos de Coortes , DNA Viral/genética , Feminino , Infecções por HIV/virologia , Humanos , Estudos Longitudinais , Masculino , Polyomaviridae/classificação , Polyomaviridae/isolamento & purificação , Infecções por Polyomavirus/virologia , GravidezRESUMO
The tumor viruses human T-lymphotropic virus 1 (HTLV-1), hepatitis C virus (HCV), Merkel cell polyomavirus (MCPyV), high-risk human papillomaviruses (HR-HPVs), Epstein-Barr virus (EBV), Kaposi's sarcoma-associated herpes virus (KSHV) and hepatitis B virus (HBV) account for approximately 15% of all human cancers. Although the oncoproteins of these tumor viruses display no sequence similarity to one another, they use the same mechanisms to convey cancer hallmarks on the infected cell. Perturbed gene expression is one of the underlying mechanisms to induce cancer hallmarks. Epigenetic processes, including DNA methylation, histone modification and chromatin remodeling, microRNA, long noncoding RNA, and circular RNA affect gene expression without introducing changes in the DNA sequence. Increasing evidence demonstrates that oncoviruses cause epigenetic modifications, which play a pivotal role in carcinogenesis. In this review, recent advances in the role of host cell epigenetic changes in virus-induced cancers are summarized.
Assuntos
Metilação de DNA , Epigenômica , Neoplasias/patologia , Vírus Oncogênicos/patogenicidade , Infecções Tumorais por Vírus/complicações , Animais , Humanos , Neoplasias/etiologia , Neoplasias/metabolismo , Infecções Tumorais por Vírus/virologiaRESUMO
On the March 11, 2020, the World Health Organization (WHO) declared the novel coronavirus disease 2019 (COVID-19) outbreak as a pandemic. The first cases in Italy were reported on January 30, 2020, and quickly the number of cases escalated. On March 20, 2020, according to the Italian National Institute of Health (ISS) and National Institute of Statistics (ISTAT), the peak of COVID-19 cases reported in Italy reached the highest number, surpassing those in China. The Italian government endorsed progressively restrictive measures initially at the local level, and finally, at the national level with a lockdown of the entire Italian territory up to 3 May 2020. The complete Italian territory closing slowed down the contagion. This review retraces the main numbers of the pandemic in Italy. Although in decline, the new reported cases remain high in the northern regions. Since drugs or vaccines are still not available, the described framework highlights the importance of the containment measures to be able to quickly identify all the potential transmission hotspots and keep control subsequent epidemic waves of COVID-19.
Assuntos
COVID-19/epidemiologia , COVID-19/prevenção & controle , Controle de Doenças Transmissíveis/métodos , Humanos , Itália/epidemiologia , SARS-CoV-2RESUMO
Coronavirus disease 2019 (COVID-19), first reported in Wuhan, the capital of Hubei, China, has been associated to a novel coronavirus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In March 2020, the World Health Organization declared the SARS-CoV-2 infection a global pandemic. Soon after, the number of cases soared dramatically, spreading across China and worldwide. Italy has had 12,462 confirmed cases according to the Italian National Institute of Health (ISS) as of March 11, and after the "lockdown" of the entire territory, by May 4, 209,254 cases of COVID-19 and 26,892 associated deaths have been reported. We performed a review to describe, in particular, the origin and the diffusion of COVID-19 in Italy, underlying how the geographical circulation has been heterogeneous and the importance of pathophysiology in the involvement of cardiovascular and neurological clinical manifestations.
Assuntos
Doenças Cardiovasculares/epidemiologia , Infecções por Coronavirus/epidemiologia , Síndrome da Liberação de Citocina/epidemiologia , Doenças do Sistema Nervoso/epidemiologia , Pandemias , Pneumonia Viral/epidemiologia , Síndrome Respiratória Aguda Grave/epidemiologia , Fatores Etários , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , COVID-19 , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/virologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/transmissão , Síndrome da Liberação de Citocina/diagnóstico , Síndrome da Liberação de Citocina/mortalidade , Síndrome da Liberação de Citocina/virologia , Geografia , Humanos , Itália/epidemiologia , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/mortalidade , Doenças do Sistema Nervoso/virologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/mortalidade , Pneumonia Viral/transmissão , Prevalência , SARS-CoV-2 , Síndrome Respiratória Aguda Grave/diagnóstico , Síndrome Respiratória Aguda Grave/mortalidade , Síndrome Respiratória Aguda Grave/transmissão , Fatores Sexuais , Análise de SobrevidaRESUMO
BACKGROUND: During severe immunosuppression or treatment with specific biological drugs, human polyomavirus JC (JCPyV) may establish a lytic infection in oligodendrocytes, leading to progressive multifocal leukoencephalopathy (PML). Beyond AIDS, which represents the most common predisposing condition, several biological drugs have been associated to the development of PML, such as natalizumab, fingolimod and dimethyl fumarate, which have been showed to increase the risk of PML in the multiple sclerosis (MS) population. JCPyV non-coding control region (NCCR) can be found in two different forms: a virulent neurotropic pathogenic form and a latent non-pathogenic form. The neurotropic forms contain a rearranged NCCR and are typically found in the cerebrospinal fluid, brain or blood of PML patients. CASE PRESENTATION: We sequenced and critically examined JCPyV NCCR from isolates detected in the cerebrospinal fluid of four newly diagnosed progressive multifocal leukoencephalopathy patients: two HIV-positive and two HIV-negative multiple sclerosis patients. More complex NCCR rearrangements were observed in the two HIV-positive patients compared to the HIV-negative multiple sclerosis patients with PML. CONCLUSIONS: The comparison of HIV-positive and HIV-negative MS patients with PML, allowed us to evidence the presence of a common pattern of JCPyV NCCR rearrangement, characterized by the deletion of the D-block, which could be one of the initial rearrangements of JCPyV NCCR needed for the development of PML.
Assuntos
Encéfalo/patologia , DNA Viral/genética , Rearranjo Gênico , Vírus JC/genética , Vírus JC/patogenicidade , Leucoencefalopatia Multifocal Progressiva/patologia , Adulto , Idoso , Encéfalo/virologia , Feminino , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/patologia , Sequências Reguladoras de Ácido Nucleico , Fatores de RiscoRESUMO
Merkel cell polyomavirus (MCPyV) viral protein 1 (VP1) is the capsid protein that mediates virus attachment to host cell receptors and is the major immune target. Given the limited data on MCPyV VP1 mutations, the VP1 genetic variability was examined in 100 plasma and 100 urine samples from 100 HIV+ individuals. Sequencing of VP1 DNA in 17 urine and 17 plasma specimens, simultaneously MCPyV DNA positive, revealed that 27 samples displayed sequences identical to VP1 of MCC350 strain. VP1 from two urine specimens had either Thr47Ser or Ile115Phe substitution, whereas VP1 of one plasma contained Asp69Val and Ser251Phe substitutions plus deletion (∆) of Tyr79. VP1 DNA in the remaining samples had mutations encoding truncated protein. Three-dimensional prediction models revealed that Asp69Val, Ser251Phe, and Ile115Phe caused neutral effects while Thr47Ser and Tyr79∆ produced a deleterious effect reducing VP1 stability. A549 cells infected with urine or plasma samples containing full-length VP1 variants with substitutions, sustained viral DNA replication and VP1 expression. Moreover, medium harvested from these cells was able to infect new A549 cells. In cells infected by samples with truncated VP1, MCPyV replication was hampered. In conclusion, MCPyV strains with unique mutations in the VP1 gene are circulating in HIV+ patients. These strains display altered replication efficiency compared to the MCC350 prototype strain in A549 cells.
Assuntos
Substituição de Aminoácidos , Proteínas do Capsídeo/química , Infecções por HIV/virologia , Poliomavírus das Células de Merkel/fisiologia , Infecções por Polyomavirus/virologia , Células A549 , Adulto , Idoso , Proteínas do Capsídeo/genética , Estudos Transversais , Feminino , Infecções por HIV/sangue , Infecções por HIV/urina , HIV-1/patogenicidade , Humanos , Masculino , Poliomavírus das Células de Merkel/genética , Pessoa de Meia-Idade , Modelos Moleculares , Plasma/virologia , Infecções por Polyomavirus/sangue , Infecções por Polyomavirus/genética , Infecções por Polyomavirus/urina , Conformação Proteica , Estabilidade Proteica , Urina/virologia , Replicação Viral , Adulto JovemRESUMO
BKPyV replication is a risk factor for the development of polyomavirus-associated nephropathy in kidney transplant recipients. Here, the case of a 42 years old Caucasian patient is described who developed a kidney allograft failure because of uncontrolled BKPyV replication 7 months after transplant despite a strong reduction of the immunosuppressive therapy. The genetic analysis of the noncoding control region did not show rearrangement but two point mutations at nucleotide positions 18 and 31 within P block. The mutation at position 31 involved the nuclear factor-1 site. Sequencing of the VP1 region revealed a subtype I/subgroup b-1.
Assuntos
Vírus BK/fisiologia , Sobrevivência de Enxerto , Transplante de Rim , Infecções por Polyomavirus/virologia , Adulto , Vírus BK/classificação , Biópsia , DNA Viral , Humanos , Transplante de Rim/efeitos adversos , Masculino , Filogenia , Transplante Homólogo , Replicação ViralRESUMO
Fragmented data are available on the human polyomaviruses (HPyVs) prevalence in the gastrointestinal tract. Rearrangements in the non-coding control region (NCCR) of JCPyV and BKPyV have been extensively studied and correlated to clinical outcome; instead, little information is available for KIPyV, WUPyV and MCPyV NCCRs. To get insights into the role of HPyVs in the gastrointestinal tract, we investigated JCPyV, BKPyV, KIPyV, WUPyV and MCPyV distribution among hematological patients in concomitance with gastrointestinal symptoms. In addition, NCCRs and VP1 sequences were examined to characterize the strains circulating among the enrolled patients. DNA was extracted from 62 stool samples and qPCR was carried out to detect and quantify JCPyV, BKPyV, KIPyV, WUPyV and MCPyV genomes. Positive samples were subsequently amplified and sequenced for NCCR and VP1 regions. A phylogenetic tree was constructed aligning the obtained VP1 sequences to a set of reference sequences. qPCR revealed low viral loads for all HPyVs searched. Mono and co-infections were detected. A significant correlation was found between gastrointestinal complications and KIPyV infection. Archetype-like NCCRs were found for JCPyV and BKPyV, and a high degree of NCCRs stability was observed for KIPyV, WUPyV and MCPyV. Analysis of the VP1 sequences revealed a 99% identity with the VP1 reference sequences. The study adds important information on HPyVs prevalence and persistence in the gastrointestinal tract. Gastrointestinal signs were correlated with the presence of KIPyV, although definitive conclusions cannot be drawn. HPyVs NCCRs showed a high degree of sequence stability, suggesting that sequence rearrangements are rare in this anatomical site.
Assuntos
Fezes/virologia , Variação Genética , Neoplasias Hematológicas/complicações , Infecções por Polyomavirus/epidemiologia , Infecções por Polyomavirus/virologia , Polyomavirus/isolamento & purificação , Eliminação de Partículas Virais , Adulto , Criança , Feminino , Humanos , Masculino , Filogenia , Polyomavirus/classificação , Polyomavirus/genética , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Carga ViralRESUMO
John Cunningham virus (JCV), the etiological agent of progressive multifocal leukoencephalopathy (PML), is the first human polyomavirus described. After asymptomatic primary infection which occurs in childhood, the virus spreads by the hematogenous route from the primary site of infection to secondary sites including kidneys, lymphoid tissues, peripheral blood leukocytes, and brain to establish latent infection. During immunosuppression the virus undergoes molecular rearrangements that allow it to replicate in glial tissues causing PML. PML occurs in people with underlying immunodeficiency or in individuals being treated with potent immunomodulatory therapies. Although the hypothesis that immune deficiency is a predisposing factor for PML, there are many unsolved issues including the pathogenic mechanisms related to the interaction of JCV infection/reactivation with the host. This is due to the difficulty of propagating the virus in human cell cultures and the absence of an animal model. This review updates current understanding in the context of JCV and human disease.
Assuntos
Vírus JC/fisiologia , Leucoencefalopatia Multifocal Progressiva/virologia , Regulação Viral da Expressão Gênica , Genoma Viral , Humanos , Vírus JC/genética , Leucoencefalopatia Multifocal Progressiva/imunologia , Leucoencefalopatia Multifocal Progressiva/patologiaRESUMO
BACKGROUND: Infection of glial cells by human neurotropic polyomavirus JC (JCV), the causative agent of the CNS demyelinating disease progressive multifocal leukoencephalopathy (PML), rapidly inflicts damage to cellular DNA. This activates DNA damage response (DDR) signaling including induction of expression of DNA repair factor Rad51. We previously reported that Rad51 co-operates with the transcription factor NF-κB p65 to activate JCV early transcription. Thus Rad51 induction by JCV infection may provide positive feedback for viral activation early in JCV infection. DDR is also known to stimulate NF-κB activity, a phenomenon known as nucleus to cytoplasm or "inside-out" NF-κB signaling, which is initiated by Ataxia telangiectasia mutated (ATM) protein, a serine/threonine kinase recruited and activated by DNA double-strand breaks. Downstream of ATM, there occurs a series of post-translational modifications of NF-κB essential modulator (NEMO), the γ regulatory subunit of inhibitor of NF-κB (IκB) kinase (IKK), resulting in NF-κB activation. METHODS: We analyzed the effects of downstream pathways in the DDR by phosphospecific Western blots and analysis of the subcellular distribution of NEMO by cell fractionation and immunocytochemistry. The role of DDR in JCV infection was analyzed using a small molecule inhibitor of ATM (KU-55933). NEMO sumoylation was investigated by Western and association of ATM and NEMO by immunoprecipitation/Western blots. RESULTS: We show that JCV infection caused phosphorylation and activation of ATM while KU-55933 inhibited JCV replication. JCV infection caused a redistribution of NEMO from cytoplasm to nucleus. Co-expression of JCV large T-antigen and FLAG-tagged NEMO showed the occurrence of sumoylation of NEMO, while co-expression of ATM and FLAG-NEMO demonstrated physical association between ATM and NEMO. CONCLUSIONS: We propose a model where JCV infection induces both overexpression of Rad51 protein and activation of the nucleus to cytoplasm NF-κB signaling pathway, which then act together to enhance JCV gene expression.
Assuntos
Dano ao DNA , Interações Hospedeiro-Patógeno , Vírus JC/crescimento & desenvolvimento , NF-kappa B/metabolismo , Neuroglia/virologia , Transdução de Sinais , Estresse Fisiológico , Western Blotting , Fracionamento Celular , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Regulação Viral da Expressão Gênica , Humanos , Quinase I-kappa B/análise , Imuno-Histoquímica , Vírus JC/genética , Modelos Biológicos , Transporte Proteico , Rad51 Recombinase/metabolismo , Transcrição GênicaRESUMO
John Cunningham virus (JCPyV) is an ubiquitous human pathogen that causes disease in immunocompromised patients. The JCPyV genome is composed of an early region and a late region, which are physically separated by the non-coding control region (NCCR). The DNA sequence of the NCCR distinguishes two forms of JCPyV, the designated archetype and the prototype, which resulted from a rearrangement of the archetype sequence. To date, the cell culture systems for propagating JCPyV archetype have been very limited in their availability and robustness. Prior to this study, it was demonstrated that JCPyV archetype DNA replicates in COS-7 simian kidney cells expressing SV40 TAg and COS-7 cells expressing HIV-1 Tat. Based on these observations, the present study was conducted to reproduce an in vitro model in COS-7 cells transfected with the JCPyV archetype strain in order to study JCPyV DNA replication and analyze NCCR rearrangements during the viral life cycle. The efficiency of JCPyV replication was evaluated by quantitative PCR (Q-PCR) and by hemagglutination (HA) assay after transfection. In parallel, sequence analysis of JCPyV NCCR was performed. JCPyV efficiently replicated in kidney-derived COS-7 cells, as demonstrated by a progressive increase in viral load and virion particle production after transfection. The archetypal structure of NCCR was maintained during the viral cycle, but two characteristic point mutations were detected 28 days after transfection. This model is a useful tool for analyzing NCCR rearrangements during in vitro replication in cells that are sites of viral persistence, such as tubular epithelial cells of the kidney.
Assuntos
Adaptação Biológica , Rearranjo Gênico , Vírus JC/crescimento & desenvolvimento , Vírus JC/genética , Animais , Células COS , Chlorocebus aethiops , Testes de Hemaglutinação , Humanos , Mutação Puntual , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA , Transfecção , Cultura de VírusRESUMO
Progressive multifocal leukoencephalopathy (PML) is a devastating and often fatal demyelinating disease of the central nervous system for which effective therapies are lacking. It is caused by the replication of polyomavirus JC (JCV) in the oligodendrocytes and astrocytes leading to their cytolytic death and loss of myelin from the subcortical white matter. While the virus is very common in human populations worldwide, the incidence of the disease is very low and confined almost exclusively to individuals with some form of immunological dysfunction. However, the number of people who constitute the at-risk population is growing larger and includes individuals with HIV-1/AIDS and patients receiving immunomodulatory therapies such as multiple sclerosis patients treated with natalizumab. Further adding to the public health significance of this disease are the difficulties encountered in the diagnosis of PML and the lack of useful biomarkers for PML progression. In this review, we examine the diagnostic assays that are available for different aspects of the JCV life cycle, their usefulness and drawbacks, and the prospects for improvements.
Assuntos
Anticorpos Antivirais/sangue , Biomarcadores/sangue , Hospedeiro Imunocomprometido/imunologia , Vírus JC/imunologia , Leucoencefalopatia Multifocal Progressiva/diagnóstico , RNA Viral/sangue , Carga Viral/métodos , Síndrome da Imunodeficiência Adquirida/imunologia , Astrócitos/virologia , Biomarcadores/análise , Sistema Nervoso Central/patologia , Sistema Nervoso Central/virologia , Humanos , Leucoencefalopatia Multifocal Progressiva/virologia , Oligodendroglia/virologiaRESUMO
The nuclear magnetic resonance (NMR)-based metabolomic approach was used as analytical methodology to study the urine samples of chronic inflammatory rheumatic disease (CIRD) patients. The urine samples of CIRD patients were compared to the ones of both healthy subjects and patients with multiple sclerosis (MS), another immuno-mediated disease. Urine samples collected from 39 CIRD patients, 25 healthy subjects, and 26 MS patients were analyzed using 1H NMR spectroscopy, and the NMR spectra were examined using partial least squares-discriminant analysis (PLS-DA). PLS-DA models were validated by a double cross-validation procedure and randomization tests. Clear discriminations between CIRD patients and healthy controls (average diagnostic accuracy 83.5 ± 1.9%) as well as between CIRD patients and MS patients (diagnostic accuracy 81.1 ± 1.9%) were obtained. Leucine, alanine, 3-hydroxyisobutyric acid, hippuric acid, citric acid, 3-hydroxyisovaleric acid, and creatinine contributed to the discrimination; all of them being in a lower concentration in CIRD patients as compared to controls or to MS patients. The application of NMR metabolomics to study these still poorly understood diseases can be useful to better clarify the pathologic mechanisms; moreover, as a holistic approach, it allowed the detection of, by means of anomalous metabolic traits, the presence of other pathologies or pharmaceutical treatments not directly connected to CIRDs, giving comprehensive information on the general health state of individuals. Graphical abstract NMR-based metabolomic approach as a tool to study urine samples in CIRD patients with respect to MS patients and healthy controls.
Assuntos
Espectroscopia de Ressonância Magnética/métodos , Metabolômica , Doenças Reumáticas/urina , Adulto , Estudos de Casos e Controles , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/urinaRESUMO
We evaluated the reliability and accuracy of the combined use of MALDI-TOF MS and classical ID VITEK2 to identify monomicrobial infection in blood culture bottles. In total, 70 consecutive positive blood cultures were included in this study. Positive blood culture bottles were subjected to Gram staining and subcultured on solid media. Isolates grown from such culture media were used for classical ID using VITEK2 system. In parallel, an aliquot was subjected to a lysing-centrifugation method and used for the identification with the MALDI-TOF system. Results evidenced the correct genus and species identification of 91.4 % of microorganisms responsible for bacteremia with an agreement to the species and the genus level. If compared with the standard method VITEK2, our simple and cost-effective sample preparation method would be very useful for rapid identification of microorganisms using blood culture bottles. In fact, the direct method showed rapid and reliable results, especially for the gram-negative group.