Modulation of potassium channels inhibits bunyavirus infection

Bunyaviruses are considered to be emerging pathogens facilitated by the segmented nature of their genome that allows reassortment between different species to generate novel viruses with altered pathogenicity. Bunyaviruses are transmitted via a diverse range of arthropod vectors, as well as rodents, and have established a global disease range with massive importance in healthcare, animal welfare and economics. There are no vaccines or anti-viral therapies available to treat human bunyavirus infections and so development of new anti-viral strategies is urgently required. Bunyamwera virus (BUNV; genus Orthobunyavirus) is the model bunyavirus, sharing aspects of its molecular and cellular biology with all Bunyaviridae family members. Here, we show for the first time that BUNV activates and requires cellular potassium (K+) channels to infect cells. Time of addition assays using K+ channel modulating agents demonstrated that K+ channel function is critical to events shortly after virus entry but prior to viral RNA synthesis/replication. A similar K+ channel dependence was identified for other bunyaviruses namely Schmallenberg virus (Orthobunyavirus) as well as the more distantly related Hazara virus (Nairovirus). Using a rational pharmacological screening regimen, twin-pore domain K+ channels (K2P) were identified as the K+ channel family mediating BUNV K+ channel dependence. As several K2P channel modulators are currently in clinical use, our work suggests they may represent a new and safe drug class for the treatment of potentially lethal bunyavirus disease

Determinação de autoanticorpos para antígenos da mielina no soro de pacientes HLA - DQB1*0602 com esclerose múltipla

Esclerose múltipla (EM) é doença inflamatória desmielinizante do sistema nervoso central (SNC) de natureza autoimune, mediada por linfócitos Th1. A produção de autoanticorpos séricos para proteína básica da mielina (MBP), proteolipídeo PLP e sequência da glicoproteína de oligodendrócito MOG 92-106, foi determinada em 54 indivíduos saudáveis e 26 pacientes com EM expressando ou não o alelo de suscetibilidade HLA-DQB1*0602. Independentemente da expressão do alelo DQB1*0602, todos os pacientes apresentaram produção marcante (p< 0,0001) de autoanticorpos isotipo IgG para MBP e MOG 92-106, e do isotipo IgA para PLP e MOG 92-106. Os resultados sugerem que outros alelos HLA da classe II exerçam influência na suscetibilidade à EM e no reconhecimento imunológico dos antígenos encefalitogênicos, determinando o padrão de resposta autoimune e contribuindo na manutenção e/ou controle da inflamação no SNC

Prevalence of human papillomavirus DNA in female cervical lesions from Rio de Janeiro, Brazil

A hundred-sixty paraffin-embedded specimens from female cervical lesions were examined for human papillomavirus (HPV) types 6, 11, 16 and 18 infections by non-isotopic in situ hybridization. The data were compared with histologic diagnosis. Eighty-eight (55) biopsies contained HPV DNA sequences. In low grade cervical intraepithelial neoplasias (CIN I), HPV infection was detected in 78.7 of the cases, the benign HPV 6 was the most prevalent type. HPV DNA was detected in 58 of CIN II and CIN III cases and in 41.8 of squamous cell carcinomas (SCC). Histologically normal women presented 20 of HPV infection. Oncogenic HPV was found in 10 of these cases, what may indicate a higher risk of developing CINs and cancer. Twenty-five percent of the infected tissues contained mixed infections. HPV 16 was the most common type infecting the cervix and its prevalence raised significantly with the severity of the lesions, pointing its role in cancer pathogenesis. White women presented twice the cervical lesions of mulatto and African origin women, although HPV infection rates were nearly the same for the three groups (approximately 50). Our results showed that HPV typing by in situ hybridization is a useful tool for distinguishing between low and high risk cervical lesions. Further studies are required to elucidate risk factors associated with HPV infection and progression to malignancy in Brazilian population

Inhibition of HIV-1 replication in human primary cells by a Dolabellane Diterpene isolated from the marine Algae Dictyota pfaffii

Submitted by Sandra Infurna ([email protected]) on 2020-01-03T13:14:27Z No. of bitstreams: 1 LuizRR_CasteloBranco_etal_IOC_2006.pdf: 88033 bytes, checksum: 1c07f1773a945cdb2a8eece147efc60a (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2020-01-03T13:29:06Z (GMT) No. of bitstreams: 1 LuizRR_CasteloBranco_etal_IOC_2006.pdf: 88033 bytes, checksum: 1c07f1773a945cdb2a8eece147efc60a (MD5)Made available in DSpace on 2020-01-03T13:29:06Z (GMT). No. of bitstreams: 1 LuizRR_CasteloBranco_etal_IOC_2006.pdf: 88033 bytes, checksum: 1c07f1773a945cdb2a8eece147efc60a (MD5) Previous issue date: 2006Universidade Federal Fluminense. Departamento de Biologia Celular e Molecular. Laboratório de Virologia Molecular. Niterói, RJ, Brasil / Universidade Federal do Rio de Janeiro. Instituto de Microbiologia Prof. Paulo de Góes. Rio de Janeiro, RJ, Brasil / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Laboratório de Imunologia Clínica. Rio de Janeiro, RJ, Brasil.Universidade Federal Fluminense. Departamento de Biologia Marinha. Laboratório de Biologia Marinha. Niteói, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Laboratório de Imunologia Clínica. Rio de Janeiro, RJ, Brasil.Universidade Federal Fluminense. Departamento de Biologia Celular e Molecular. Laboratório de Virologia Molecular. Niterói, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Laboratório de Imunologia Clínica. Rio de Janeiro, RJ, Brasil.We describe in this paper that the dolabellane diterpene 8,10,18-trihydroxy-2,6-dolabelladiene (3), isolated from the marine algae Dictyota pfaffii, inhibits the HIV-1 infection in human primary cells and tumor cell lines. We initially observed that compound 3 inhibited the activity of a purified HIV-1 enzyme reverse transcriptase (RT) in a dose-dependent manner, with an IC (50) value of 16.5 +/- 4.3 microM. Next, we found that compound 3 inhibited HIV-1 infection by an R5-tropic isolate in peripheral blood mononuclear cells (PBMCs) in a dose-dependent manner with an EC (50) value of 8.4 +/- 2.8 microM. The replication of HIV-1 isolates presenting distinct tropism for chemokine receptors was also inhibited, as analyzed in PBMCs or U87 cells infected with R5-, X4- or R5X4-tropic isolates. Likewise, compound 3 blocked HIV-1 infection in macrophages by R5 and R5X4 viruses in a dose-dependent manner with EC (50) values of 1.7 +/- 0.6 microM and 1.85 +/- 0.75 microM, respectively. Compound 3 sustained antiretroviral activity even when added to HIV-1-infected Sup-T1 cells at 12 h after infection, suggesting that, as well as inhibiting HIV-1 RT, it also blocks HIV-1 replication at a post transcriptional step. Our results support further investigations on compound 3 pharmacokinetics and we propose that this diterpene could be considered as a potential compound for HIV-1 therapy

Human papillomavirus detection in genital lesions by in situ hybridization and ultrastructural observations

Detection of papillomavirus DNA in sity hybridization technique was perfomed in 29 symptomatic patients (6 males and 23 females) during the period of 1989-1991 at the Clinic for Sexually Transmitted Diseases, Universidade Federal Fluminense, State of rio de Janeiro. All the male patients had condyloma acuminata. Only HPV 6/11 were found in these lesions. Clinical features inthe female patients included vulvar condyloma acuminata, bowenoid populosis, flat cervical condyloma, cervical condyloma acuminatum and cervical intraepithelialneoplasia grade II (CIN II). We also found cases of condyloma acuminata associated to vulvar intraepithelial neoplasia grade III (VIN III), as well as to vaginal invasive carcinoma. HPV 6/11 and 16/18 were found in vulvar condyloma acuminata. Mixed infection by 6/11-16/18 HPV were also seen in these lesions as well as in the patient who had cervical condyloma acuminatum. HPV 16/18 were found in the condyloma acuminatum plus VIN III and in the CIN II lesions. We have found HPV31/33/51 in the specimen of condyloma acuminatum plus invasive carcinoma. In order to investigate the ultrastructural aspects of HPV infection in genital tissue, the biopsies of three female patients were observed under electron microscope.Mature virus particles were found in the cells of a condyloma acuminatum as wellas in the condyloma acuminatum plus invasive carcinoma case. In another sample, chromosome breakages were found in the nuclei of the infected cells although no viral particles were observed