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Sample records for cell lymphotropic virus

  1. Cytokine production by endothelial cells infected with human T cell lymphotropic virus type I.

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    H. Takashima; Eguchi, K.; Kawakami, A; Kawabe, Y; Migita, K; Sakai, M; Origuchi, T; Nagataki, S.

    1996-01-01

    OBJECTIVE: To investigate the ability of human T cell lymphotropic virus type I (HTLV-I) to infect endothelial cells and induce cytokine production by these cells. METHODS: Human umbilical vein endothelial cells (HUVEC) were cocultured with HTLV-I infected T cell line (MT-2 cells) or uninfected T cell line (CEM cells). RESULTS: Following coculture with MT-2 cells, endothelial cells expressed HTLV-I specific core antigens. Endothelial cells cocultured with MT-2 cells produced significant amoun...

  2. Human T-cell lymphotropic virus in volunteer blood donors.

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    Taylor, P E; Stevens, C E; Pindyck, J; Schrode, J; Steaffens, J W; Lee, H

    1990-01-01

    Serum samples collected in 1985 and 1986 from 18,257 donors to the Greater New York Blood Program were screened by enzyme-linked immunoassay for antibody to human T-cell lymphotropic virus (anti-HTLV). Fifteen samples (0.08%) were confirmed positive: 7 by radioimmunoprecipitation assay (RIPA) alone, 6 by Western blot alone, and 2 by combined results from both tests. One donor, whose original test result was uninterpretable because multiple nonspecific bands were present on RIPA, clearly tested positive on subsequent specimens. Follow-up testing of individuals with this type of result may be needed to resolve their HTLV status. Anti-HTLV prevalence increased with age and was significantly more common in black or Hispanic donors and in those born in the Caribbean than in other donors. All anti-HTLV-positive donors were negative for antibody to HIV-1, and only one donor (7% of those positive) would have been excluded by any of the routine donor screening tests used at that time. PMID:2173176

  3. Can thymic epithelial cells be infected by human T-lymphotropic virus type 1?

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    Klaysa Moreira-Ramos

    2011-09-01

    Full Text Available The human T-lymphotropic virus type-1 (HTLV-1 is the cause of adult T cell leukaemias/lymphoma. Because thymic epithelial cells (TEC express recently defined receptors for the virus, it seemed conceivable that these cells might be a target for HTLV-1 infection. We developed an in vitro co-culture system comprising HTLV-1+-infected T cells and human TECs. Infected T cells did adhere to TECs and, after 24 h, the viral proteins gp46 and p19 were observed in TECs. After incubating TECs with culture supernatants from HTLV-1+-infected T cells, we detected gp46 on TEC membranes and the HTLV-1 tax gene integrated in the TEC genome. In conclusion, the human thymic epithelium can be infected in vitro by HTLV-1, not only via cell-cell contact, but also via exposure to virus-containing medium.

  4. Seroepidemiology of Human T-Cell Lymphotropic Virus Type-1 (HTLV1) in Mashhad

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    Safabakhsh, Hamidreza; Jalalian, Mehrdad; Karimi, Gharib

    2014-01-01

    Introduction: Human T-cell lymphotropic virus (HTLV-I) is associated with adult T cell leukemia/lymphoma (ATL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The major routes of HTLV-I transmission are mother-to-child, sexual contact, and blood transfusion. Mashhad is one of the main endemic areas in the world for HTLV-I, and minimizing the risk of HTLV-I transmission through blood transfusion is one of the main duties of the Blood Transfusion Center in Mashhad. The ...

  5. Comparison of four enzyme immunoassays for detection of human T-cell lymphotropic virus type 2 antibodies.

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    Gallo, D; Yeh, E T; Moore, E S; Hanson, C V

    1996-01-01

    Four licensed enzyme immunoassay (EIA) kits for the measurement of antibody to human T-cell lymphotropic virus (HTLV) type 1, one from Organon Teknika Corp. (OTC), one from Cambridge Biotech Corp. (CBC), and two from Abbott Laboratories (the 1993 modification [Abb 93] and the 2.0 version licensed in 1995 [Abb 95]), were evaluated for sensitivity and specificity in the detection of HTLV type 2 antibody, and the results were compared with those previously obtained with earlier kit versions. The...

  6. Discovery of a new human T-cell lymphotropic virus (HTLV-3 in Central Africa

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    Mahieux Renaud

    2005-05-01

    Full Text Available Abstract Human T-cell Leukemia virus type 1 (HTLV-1 and type 2 (HTLV-2 are pathogenic retroviruses that infect humans and cause severe hematological and neurological diseases. Both viruses have simian counterparts (STLV-1 and STLV-2. STLV-3 belongs to a third group of lymphotropic viruses which infect numerous African monkeys species. Among 240 Cameroonian plasma tested for the presence of HTLV-1 and/or HTLV-2 antibodies, 48 scored positive by immunofluorescence. Among those, 27 had indeterminate western-blot pattern. PCR amplification of pol and tax regions, using HTLV-1, -2 and STLV-3 highly conserved primers, demonstrated the presence of a new human retrovirus in one DNA sample. tax (180 bp and pol (318 bp phylogenetic analyses demonstrated the strong relationships between the novel human strain (Pyl43 and STLV-3 isolates from Cameroon. The virus, that we tentatively named HTLV-3, originated from a 62 years old Bakola Pygmy living in a remote settlement in the rain forest of Southern Cameroon. The plasma was reactive on MT2 cells but was negative on C19 cells. The HTLV 2.4 western-blot exhibited a strong reactivity to p19 and a faint one to MTA-1. On the INNO-LIA strip, it reacted faintly with the generic p19 (I/II, but strongly to the generic gp46 (I/II and to the specific HTLV-2 gp46. The molecular relationships between Pyl43 and STLV-3 are thus not paralleled by the serological results, as most of the STLV-3 infected monkeys have an "HTLV-2 like" WB pattern. In the context of the multiple interspecies transmissions which occurred in the past, and led to the present-day distribution of the PTLV-1, it is thus very tempting to speculate that this newly discovered human retrovirus HTLV-3 might be widespread, at least in the African continent.

  7. Sexual transmission of human T-cell lymphotropic virus type 1

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    Arthur Paiva

    2014-06-01

    Full Text Available Human T-cell lymphotropic virus type 1 (HTLV-1 is endemic in many parts of the world and is primarily transmitted through sexual intercourse or from mother to child. Sexual transmission occurs more efficiently from men to women than women to men and might be enhanced by sexually transmitted diseases that cause ulcers and result in mucosal ruptures, such as syphilis, herpes simplex type 2 (HSV-2, and chancroid. Other sexually transmitted diseases might result in the recruitment of inflammatory cells and could increase the risk of HTLV-1 acquisition and transmission. Additionally, factors that are associated with higher transmission risks include the presence of antibodies against the viral oncoprotein Tax (anti-Tax, a higher proviral load in peripheral blood lymphocytes, and increased cervicovaginal or seminal secretions. Seminal fluid has been reported to increase HTLV replication and transmission, whereas male circumcision and neutralizing antibodies might have a protective effect. Recently, free virions were discovered in plasma, which reveals a possible new mode of HTLV replication. It is unclear how this discovery might affect the routes of HTLV transmission, particularly sexual transmission, because HTLV transmission rates are significantly higher from men to women than women to men.

  8. Cross-reactivity to human T-lymphotropic virus type III/lymphadenopathy-associated virus and molecular cloning of simian T-cell lymphotropic virus type III from African green monkeys.

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    Hirsch, V.; Riedel, N.; Kornfeld, H; Kanki, P J; M Essex; Mullins, J I

    1986-01-01

    Simian T-lymphotropic retroviruses with structural, antigenic, and cytopathic features similar to the etiologic agent of human acquired immunodeficiency syndrome, human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV), have been isolated from a variety of primate species including African green monkeys (STLV-IIIAGM). This report describes nucleic acid cross-reactivity between STLV-IIIAGM and HTLV-III/LAV, molecular cloning of the STLV-IIIAGM genome, and evaluation...

  9. Human T cell lymphotropic virus type 1 infection among U.S. thalassemia patients.

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    Switzer, William M; Shankar, Anupama; Trimble, Sean R; Thompson, Alexis A; Giardina, Patricia J; Cohen, Alan R; Coates, Thomas D; Vichinsky, Elliott; Neufeld, Ellis J; Boudreaux, Jeanne M; Heneine, Walid

    2013-07-01

    Thalassemia is an inherited genetic disorder requiring multiple transfusions to treat anemia caused by low hemoglobin levels. Thus, thalassemia patients are at risk for infection with blood-borne pathogens, including human T cell lymphotropic viruses (HTLV) that are transmitted by transfusion of cellular blood products. Here, we examined the prevalence of HTLV among 234 U.S. thalassemia patients using sera collected in 2008. Sera were tested for antibodies to HTLV-1/2 using enzyme immunoassay (EIA) and a confirmatory western blot (WB) that differentiates between HTLV-1 and HTLV-2. Demographic information and clinical information were collected at study enrollment, including HIV and hepatitis C virus (HCV) status. Three patients (1.3%) were WB positive; two were HTLV-1 and one could not be serotyped as HTLV-1/2. All three HTLV-positive persons were HIV-1 negative and one was HCV seropositive. The HTLV seroprevalence was higher than that of HIV-1 (0.85%) and lower than HCV (18.8%) in this population. All three patients (ages 26-46 years) were diagnosed with β-thalassemia shortly after birth and have since been receiving multiple transfusions annually. Two of the HTLV-positive patients confirmed receiving transfusions before HTLV blood screening was implemented in 1988. We identified a substantial HTLV-1 seroprevalence in U.S. thalassemia patients that is much greater than that seen in blood donors. Our findings highlight the importance of HTLV testing of patients with thalassemia and other diseases requiring multiple transfusions, especially in recipients of unscreened transfusions. In addition, appropriate counseling and follow-up of HTLV-infected patients are warranted. PMID:23409829

  10. Effect of using heat-inactivated serum with the Abbott human T-cell lymphotropic virus type III antibody test.

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    Jungkind, D. L.; DiRenzo, S A; Young, S J

    1986-01-01

    The Abbott enzyme immunoassay (Abbott Laboratories, North Chicago, Ill.) for human T-cell lymphotropic virus type III (HTLV-III) antibody was evaluated to determine the effect of using heat-inactivated (56 degrees C for 30 min) serum as the sample. Each of 58 nonreactive serum samples gave a higher A492 value when tested after heat inactivation. Ten of the samples became reactive after heating. Heat-inactivated serum should not be used in the current Abbott HTLV-III antibody test, because thi...

  11. Transcriptional activation of JC virus by human T-lymphotropic virus type I Tax protein in human neuronal cell lines.

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    Okada, Y; Sawa, H; Tanaka, S; Takada, A; Suzuki, S; Hasegawa, H; Umemura, T; Fujisawa, J; Tanaka, Y; Hall, W W; Nagashima, K

    2000-06-01

    Polyomavirus JC (JCV) causes the human demyelinating disease, progressive multifocal leukoencephalopathy (PML). The recent demonstration of cases of PML in association with human T-lymphotropic virus type I (HTLV-I) infection prompted us to examine whether the HTLV-I-encoded regulatory protein Tax activates JCV transcription. By employing a dual luciferase assay, we initially found that the expression of Tax activated the transcriptional potential of both early and late promoters of JCV in human neuronal but not in non-neuronal cells. We subsequently analyzed the mechanism of Tax-induced activation of the JCV promoter in neuronal cells with the following results: 1) the JCV promoter that lacks the NF-kappaB-binding motif could not be activated by Tax; 2) the overexpression of IkappaBalpha abolished Tax-induced transcriptional activation of the JCV promoter; 3) a Tax mutant (M22) lacking the potential for activation via the NF-kappaB pathway did not activate the JCV promoter. Furthermore, Tax enhances the gene expression of JCV T antigen and VP1. We examined mechanisms of the cell-specific activation of the JCV promoter by Tax. Electrophoretic mobility shift assay demonstrated the presence of Tax-bound protein(s) that were specifically present in non-neuronal cells. This study is the first demonstration of the activation of JCV promoter by HTLV-I Tax in an NF-kappaB-dependent manner. PMID:10828075

  12. Human T-cell lymphotropic virus type III infection in a cohort of homosexual men in New York City

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    Using blood samples collected since 1978, the authors investigated the epidemiology of human T-cell lymphotropic virus type III (HTLV-III), the etiologic agent of the acquired immunodeficiency syndrome, in a group of 378 homosexually active men who have resided in New York City since the acquire immunodeficiency syndrome epidemic began. The anti-HTLV-III prevalence was 6.6% in sera from 1978 or 1979, and the subsequent annual incidence of seroconversion among susceptible men ranged between 5.5% and 10.6%. The highest incidences were in recent years, even though these men reported a decrease in their sexual activity during this time. These data demonstrate the continuing risk of HTLV-III infections in the homosexual population studied and emphasize the need for more effective prevention of transmission. The year during which antibody was first present was the only factor identified that was associated with altered cell-mediated immunity in antibody-positive men

  13. Human T-cell lymphotropic virus type III infection in a cohort of homosexual men in New York City

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    Stevens, C.E.; Taylor, P.E.; Zang, E.A.; Morrison, J.M.; Harley, E.J.; de Cordoba, S.R.; Bacino, C.; Ting, R.C.; Bodner, A.J.; Sarngadharan, M.G.; Gallo, R.C.

    1986-04-25

    Using blood samples collected since 1978, the authors investigated the epidemiology of human T-cell lymphotropic virus type III (HTLV-III), the etiologic agent of the acquired immunodeficiency syndrome, in a group of 378 homosexually active men who have resided in New York City since the acquire immunodeficiency syndrome epidemic began. The anti-HTLV-III prevalence was 6.6% in sera from 1978 or 1979, and the subsequent annual incidence of seroconversion among susceptible men ranged between 5.5% and 10.6%. The highest incidences were in recent years, even though these men reported a decrease in their sexual activity during this time. These data demonstrate the continuing risk of HTLV-III infections in the homosexual population studied and emphasize the need for more effective prevention of transmission. The year during which antibody was first present was the only factor identified that was associated with altered cell-mediated immunity in antibody-positive men.

  14. Defective Human T-Cell Lymphotropic Virus Type I (HTLV-I) Provirus in 10 Chilean Seronegative Patients with Tropical Spastic Paraparesis or HTLV-I-Associated Myelopathy

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    Ramirez, Eugenio; Cartier, Luis; Rios, Maritza; FERNANDEZ Jorge

    1998-01-01

    We studied the presence of tax and ltr genes from human T-cell lymphotropic virus type I (HTLV-I) provirus in the peripheral blood mononuclear cells from 15 seronegative patients with tropical spastic paraparesis or HTLV-I-associated myelopathy by PCR. Only a region of the tax gene from 10 patients was amplified. The nucleotide homologies of six Chilean isolates to the ATK-1 clone ranged between 98.7 and 99.4%.

  15. Expansion of Natural Killer Cells in Peripheral Blood in a Japanese Elderly with Human T-Cell Lymphotropic Virus Type 1-Related Skin Lesions

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    Shinsaku Imashuku; Naoko Kudo; Kagekatsu Kubo; Kouichi Ohshima

    2014-01-01

    Natural killer (NK) cells were proposed to play an important role in the pathogenesis of human T-cell lymphotropic virus type 1- (HTLV-1-) associated neurologic disease. Our patient was a 77-year-old Japanese man, who had been treated for infective dermatitis associated with HTLV-1 for nearly 10 years. When referred to us, he had facial eczema/edema as well as extensive dermatitis at the neck/upper chest and nuchal area/upper back regions. Dermal lesions had CD3+CD4+ cells, but no NK cells. F...

  16. Prevalence of human T-cell lymphotropic virus types 1 and 2 in blood donors of the Caruaru Blood Center (Hemope

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    Waleska Mayara Gomes de Lima

    2013-01-01

    Full Text Available BACKGROUND: There is difficulty in gathering data on the prevalence of human T-cell lymphotropic virus in blood donors as confirmatory testing is not mandatory in Brazil. This suggests there may be an underreporting of the prevalence. OBJECTIVE: To estimate the prevalence of human T-cell lymphotropic virus types 1 and 2 in donors of a blood bank in Caruaru, Brazil. METHODS: This was an observational, epidemiological, descriptive, longitudinal and retrospective study with information about the serology of donors of the Caruaru Blood Center, Fundação de Hematologia e Hemoterapia de Pernambuco (Hemope from May 2006 to December 2010. The data were analyzed using the Excel 2010 computer program (Microsoft Office(r. RESULTS: Of 61,881 donors, 60 (0.096% individuals were identified as potential carriers of human T-cell lymphotropic virus types 1 and 2. Of these, 28 (0.045% were positive and 32 (0.051% had inconclusive results in the serological screening. Forty-five (0.072% were retested; 17 were positive (0.027% and 3 inconclusive (0.005%. After confirmatory tests, 8 were positive (0.013%. Six (75% of the confirmed cases were women. CONCLUSION: Epidemiological surveys like this are very important in order to create campaigns to attract donors and reduce the costs of laboratory tests.

  17. Seroepidemiology of human T-cell lymphotropic virus type-I in blood donors of Northeastern Iran, Sabzevar

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    Mahtab Maghsudlu

    2015-01-01

    Full Text Available Background and Objectives: Human T-cell lymphotropic virus type-I (HTLV-I infection is considered as a public health challenge in endemic areas. The virus is associated with severe diseases, such as adult T-cell leukemia/lymphoma, and HTLV-I-associated myelopathy/tropical spastic paraparesis. One of the major routes of the HTLV-I transmission includes blood transfusion. Sabzevar is located in the endemic region of HTLV-I infection. The aim of the present study was to determine the seroprevalence of HTLV-I infection in the blood donors in Sabzevar. Materials and Methods: A total of 35,067 blood donors in Sabzevar from March 2009 to April 2012 who were screened with HTLV-I on the enzyme-linked immunosorbent assay screening test were included in this survey. Reactive samples that confirmed by western blot were considered to be seropositive cases. The required data were obtained from blood donors′ database of blood transfusion service. Results: The overall prevalence of HTLV-1 based on the positive result of western blot test was 0.14%. The seropositive donors aged 17-59 years with a mean age of 38.10 ± 11.82. The prevalence rates of HTLV-I infection in 3 years of study were 0.19%, 0.14%, and 0.09%, respectively. A significant relation between age, sex, educational level, and history of blood donation was observed with seropositivity of HTLV-I. Conclusion: The improvement of donor selection and laboratory screening caused a decline in the prevalence of infection in blood donors. Given the lower prevalence of infection in regular donors with lower age and higher educational level, more efforts should be done to attract blood donors from these populations.

  18. Isokinetic trunk and knee muscle strengths and gait performance in walking patients with T-cell lymphotropic virus type 1-associated myelopathy/ tropical spastic paraparesis (HAM/TSP)

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    MIYAZAKI, MASASHI; Sakakima, Harutoshi; Goto, Tatsushi; Kiyama, Ryoji; Matsuzaki, Toshio; Ijiri, Kosei; Yoshida, Yoshihiro

    2011-01-01

    The aim of this study was to investigate the isokinetic trunk and knee muscle strengths, and examine the clinical relevance of dynamic muscle strengths and gait performance in walking patients with human T-cell lymphotropic virus type 1-associated myelopathy/ tropical spastic paraparesis (HAM/TSP). Thirteen patients with HAM/TSP (8 females and 5 males, aged 38–76) and 13 sex- and age-matched healthy control subjects participated in the study. We assessed gait speed, stride length, cadence; an...

  19. Low prevalence of human immunodeficiency virus-1 (HIV-1), HIV-2, and human T cell lymphotropic virus-1 infection in Somalia.

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    Scott, D A; Corwin, A L; Constantine, N T; Omar, M A; Guled, A; Yusef, M; Roberts, C R; Watts, D M

    1991-12-01

    A seroepidemiologic survey was conducted to determine the prevalence of human immunodeficiency virus type 1 (HIV-1), HIV-2, human T cell lymphotropic virus type I (HTLV-I), and Treponema pallidum infection among southern Somalis. Sera were collected from 1,269 study subjects in the urban area of the capital city, Mogadishu, and in the rural towns of Merka, Qoryoley, and Kismayo. The subjects included 57 prostitutes, 79 sexually transmitted disease (STD) patients, and 1,133 others, including outpatient and hospitalized patients with leprosy, tuberculosis, other infectious diseases, individuals from rehabilitation camps and secondary schools, and Ethiopian immigrants. Results indicated that none of the sera were positive for HIV-1 and HIV-2 by Western blot, but one was positive for HTLV-I. The prostitutes had a significantly higher prevalence of treponemal antibody (50.8%; P less than 0.0001) than either the STD patients (12.6%) or the other subjects (5.2%). Epidemiologic data indicated that 94% of the males and females were circumcised and only 2.6% of the males used condoms. Overall, the results of this study suggested a very low prevalence of HIV-1, HIV-2, and HTLV-I infections, especially among prostitutes and STD patients, who were considered at greatest risk of contracting these retroviral infections. PMID:1763791

  20. Expansion of Natural Killer Cells in Peripheral Blood in a Japanese Elderly with Human T-Cell Lymphotropic Virus Type 1-Related Skin Lesions

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    Shinsaku Imashuku

    2014-01-01

    Full Text Available Natural killer (NK cells were proposed to play an important role in the pathogenesis of human T-cell lymphotropic virus type 1- (HTLV-1- associated neurologic disease. Our patient was a 77-year-old Japanese man, who had been treated for infective dermatitis associated with HTLV-1 for nearly 10 years. When referred to us, he had facial eczema/edema as well as extensive dermatitis at the neck/upper chest and nuchal area/upper back regions. Dermal lesions had CD3+CD4+ cells, but no NK cells. Flow cytometry of his peripheral blood showed a phenotype of CD2+ (97%, CD3+ (17%, CD4+ (12%, CD7+ (94%, CD8+ (6%, CD11c+ (70%, CD16+ (82%, CD19+ (0%, CD20+ (0%, CD56+ (67%, HLA-DR+ (68%, and NKp46+ (36%. Absolute numbers of CD56+NK cells in the peripheral blood were in a range of 986/μL–1,270/μL. The expanded NK cells in the peripheral blood are considered to be reactive, to maintain the confinement of the HTLV-1-positive CD4+ cells in the skin, and to prevent the progression of the disease.

  1. High Circulating Frequencies of Tumor Necrosis Factor Alpha- and Interleukin-2-Secreting Human T-Lymphotropic Virus Type 1 (HTLV-1)-Specific CD4+ T Cells in Patients with HTLV-1-Associated Neurological Disease

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    Goon, Peter K. C.; Igakura, Tadahiko; Hanon, Emmanuel; Angelina J Mosley; Asquith, Becca; Gould, Keith G.; Taylor, Graham P.; Weber, Jonathan N.; Bangham, Charles R M

    2003-01-01

    Significantly higher frequencies of tumor necrosis factor alpha- and interleukin-2-secreting human T-lymphotropic virus type 1 (HTLV-1)-specific CD4+ T cells were present in the peripheral blood mononuclear cells of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients than in those of asymptomatic carriers with similar provirus loads. The data suggest that HTLV-1-specific CD4+ T cells play a role in the pathogenesis of HAM/TSP.

  2. Human T-lymphotropic virus type-1 p30 alters cell cycle G2 regulation of T lymphocytes to enhance cell survival

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    Silverman Lee

    2007-07-01

    Full Text Available Abstract Background Human T-lymphotropic virus type-1 (HTLV-1 causes adult T-cell leukemia/lymphoma and is linked to a number of lymphocyte-mediated disorders. HTLV-1 contains both regulatory and accessory genes in four pX open reading frames. pX ORF-II encodes two proteins, p13 and p30, whose roles are still being defined in the virus life cycle and in HTLV-1 virus-host cell interactions. Proviral clones of HTLV-1 with pX ORF-II mutations diminish the ability of the virus to maintain viral loads in vivo. p30 expressed exogenously differentially modulates CREB and Tax-responsive element-mediated transcription through its interaction with CREB-binding protein/p300 and while acting as a repressor of many genes including Tax, in part by blocking tax/rex RNA nuclear export, selectively enhances key gene pathways involved in T-cell signaling/activation. Results Herein, we analyzed the role of p30 in cell cycle regulation. Jurkat T-cells transduced with a p30 expressing lentivirus vector accumulated in the G2-M phase of cell cycle. We then analyzed key proteins involved in G2-M checkpoint activation. p30 expression in Jurkat T-cells resulted in an increase in phosphorylation at serine 216 of nuclear cell division cycle 25C (Cdc25C, had enhanced checkpoint kinase 1 (Chk1 serine 345 phosphorylation, reduced expression of polo-like kinase 1 (PLK1, diminished phosphorylation of PLK1 at tyrosine 210 and reduced phosphorylation of Cdc25C at serine 198. Finally, primary human lymphocyte derived cell lines immortalized by a HTLV-1 proviral clone defective in p30 expression were more susceptible to camptothecin induced apoptosis. Collectively these data are consistent with a cell survival role of p30 against genotoxic insults to HTLV-1 infected lymphocytes. Conclusion Collectively, our data are the first to indicate that HTLV-1 p30 expression results in activation of the G2-M cell cycle checkpoint, events that would promote early viral spread and T-cell

  3. Prevalence of antibody to human T cell lymphotropic virus types 1/2 among aboriginal groups inhabiting northern Argentina and the Amazon region of Peru.

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    Medeot, S; Nates, S; Recalde, A; Gallego, S; Maturano, E; Giordano, M; Serra, H; Reategui, J; Cabezas, C

    1999-04-01

    We carried out a seroepidemiologic survey to define the prevalence of human T cell lymphotropic virus types 1/2 (HTLV-1/2) infections among aboriginal populations from isolated regions of northern Argentina and the Amazon region of Peru. Antibodies against HTLV were measured with agglutination tests and confirmed with by an immunofluorescence assay (IFA) and Western blotting. Five (6.94%) of 72 samples from the Tobas Indians in Argentina were positive by the IFA; two samples were typed as HTLV-1 (2.78%), two as HTLV-2 (2.78%), and one (1.39%) could not be typed because it had similar antibody titers against both viruses. No positive samples were found among 84 Andinos Puneños and 47 Matacos Wichis Indians. Seroprevalences of 2.50% (1 of 40) and 1.43% (1 of 70) for HTLV-1 were observed among Wayku and San Francisco communities in the Amazon region of Peru, and seroprevalences of 4.54% (1 of 22) and 2.38% (1 of 42) for HTLV-2 were observed among Boca Colorada and Galilea communities. No serologic evidence of human immunodeficiency virus (HIV) infection was found among the Indians tested. These results indicated the presence of HTLV-1 and HTLV-2 in the indigenous populations of Argentina and Peru. Moreover, the lack of HIV infection indicates that the virus has probably not yet been introduced into these populations. PMID:10348238

  4. Animal models for human T-lymphotropic virus type 1 (HTLV-1) infection and transformation

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    Lairmore, Michael D.; Silverman, Lee; Ratner, Lee

    2005-01-01

    Over the past 25 years, animal models of human T-lymphotropic virus type 1 (HTLV-1) infection and transformation have provided critical knowledge about viral and host factors in adult T-cell leukemia/lymphoma (ATL). The virus consistently infects rabbits, some non-human primates, and to a lesser extent rats. In addition to providing fundamental concepts in viral transmission and immune responses against HTLV-1 infection, these models have provided new information about the role of viral prote...

  5. Accumulation of human T lymphotropic virus (HTLV)-I-specific T cell clones in HTLV-I-associated myelopathy/tropical spastic paraparesis patients.

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    Höger, T A; Jacobson, S; Kawanishi, T; Kato, T; Nishioka, K; Yamamoto, K

    1997-08-15

    Human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraperesis (HAM/TSP) is a slowly progressive neurologic disorder following infection with HTLV-I. It is characterized by spasticity and hyper-reflexia of the lower extremities, urinary bladder disturbance, lower extremity muscle weakness, and sensory disturbances. HTLV-I, as an inducer of a strong humoral and cytotoxic response, is a well-known pathogenic factor for the progression of HAM/TSP. Peptides derived from proviral tax and env genes provide epitopes recognized by T cells. We herein report an accumulation of distinct clonotypes of alpha/beta TCR+ peripheral blood T lymphocytes from HAM/TSP patients in comparison with that observed in both asymptomatic carriers and healthy controls, using the reverse-transcriptase PCR/single-strand conformation polymorphism method. We also found that some of the accumulated T cell clones in the peripheral blood and cerebrospinal fluid are HTLV-I Tax(11-19) peptide specific. Such clones were found to expand strongly after being cultured with an HTLV-I Tax(11-19) peptide. Moreover, the cultured samples exhibited a strong MHC class I-restricted cytotoxic activity against HTLV-I Tax(11-19) peptide-expressing targets, and therefore most likely also include the disease-associated T cell clones observed in the patients. This is the first report of a direct assessment of Ag-specific T cell responses in fresh PBL and cerebrospinal fluid. PMID:9257872

  6. Human T-lymphotropic virus type 1 p30 interacts with REGgamma and modulates ATM (ataxia telangiectasia mutated) to promote cell survival.

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    Anupam, Rajaneesh; Datta, Antara; Kesic, Matthew; Green-Church, Kari; Shkriabai, Nikolozi; Kvaratskhelia, Mamuka; Lairmore, Michael D

    2011-03-01

    Human T-lymphotropic virus type 1 (HTLV-1) is a causative agent of adult T cell leukemia/lymphoma and a variety of inflammatory disorders. HTLV-1 encodes a nuclear localizing protein, p30, that selectively alters viral and cellular gene expression, activates G(2)-M cell cycle checkpoints, and is essential for viral spread. Here, we used immunoprecipitation and affinity pulldown of ectopically expressed p30 coupled with mass spectrometry to identify cellular binding partners of p30. Our data indicate that p30 specifically binds to cellular ATM (ataxia telangiectasia mutated) and REGγ (a nuclear 20 S proteasome activator). Under conditions of genotoxic stress, p30 expression was associated with reduced levels of ATM and increased cell survival. Knockdown or overexpression of REGγ paralleled p30 expression, suggesting an unexpected enhancement of p30 expression in the presence of REGγ. Finally, size exclusion chromatography revealed the presence of p30 in a high molecular mass complex along with ATM and REGγ. On the basis of our findings, we propose that HTLV-1 p30 interacts with ATM and REGγ to increase viral spread by facilitating cell survival. PMID:21216954

  7. Proliferation Response to Interleukin-2 and Jak/Stat Activation of T Cells Immortalized by Human T-Cell Lymphotropic Virus Type 1 Is Independent of Open Reading Frame I Expression

    OpenAIRE

    Collins, Nathaniel D.; D’Souza, Celine; Albrecht, Björn; Robek, Michael D.; Ratner, Lee; Ding, Wei; Green, Patrick L.; Lairmore, Michael D.

    1999-01-01

    Human T-cell lymphotropic virus type 1 (HTLV-1), a complex retrovirus, encodes a hydrophobic 12-kD protein from pX open reading frame (ORF) I that localizes to cellular endomembranes and contains four minimal SH3 binding motifs (PXXP). We have demonstrated the importance of ORF I expression in the establishment of infection and hypothesize that p12I has a role in T-cell activation. In this study, we tested interleukin-2 (IL-2) receptor expression, IL-2-mediated proliferation, and Jak/Stat act...

  8. Immunopathological mechanisms of human T cell lymphotropic virus type 1 (HTLV-I) uveitis. Detection of HTLV-I-infected T cells in the eye and their constitutive cytokine production.

    OpenAIRE

    Sagawa, K; Mochizuki, M; Masuoka, K; Katagiri, K; Katayama, T.; T. Maeda; Tanimoto, A; Sugita, S.; Watanabe, T.; Itoh, K.

    1995-01-01

    The immunopathology of human T cell lymphotropic virus type 1 (HTLV-I) uveitis was addressed by using T cell clones (TCC) established from the intraocular fluid of patients with HTLV-I uveitis. Proviral DNA of HTLV-I was identified in 55 out of 94 (59%) or 13 out of 36 (36%) TCC from the ocular fluid or the peripheral blood of these patients, respectively. Most of HTLV-I-infected TCC had a CD3+ CD4+ CD8- phenotype. HTLV-I infection on TCC was confirmed by analysis of the viral mRNA, nucleotid...

  9. Human T-Lymphotropic Virus Type 1 (HTLV-1 and Regulatory T Cells in HTLV-1-Associated Neuroinflammatory Disease

    Directory of Open Access Journals (Sweden)

    Yoshihisa Yamano

    2011-08-01

    Full Text Available Human T-lymphotropic virus type 1 (HTLV-1 is a retrovirus that is the causative agent of adult T cell leukemia/lymphoma (ATL and associated with multiorgan inflammatory disorders, including HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP and uveitis. HTLV-1-infected T cells have been hypothesized to contribute to the development of these disorders, although the precise mechanisms are not well understood. HTLV-1 primarily infects CD4+ T helper (Th cells that play a central role in adaptive immune responses. Based on their functions, patterns of cytokine secretion, and expression of specific transcription factors and chemokine receptors, Th cells that are differentiated from naïve CD4+ T cells are classified into four major lineages: Th1, Th2, Th17, and T regulatory (Treg cells. The CD4+CD25+CCR4+ T cell population, which consists primarily of suppressive T cell subsets, such as the Treg and Th2 subsets in healthy individuals, is the predominant viral reservoir of HTLV-1 in both ATL and HAM/TSP patients. Interestingly, CD4+CD25+CCR4+ T cells become Th1-like cells in HAM/TSP patients, as evidenced by their overproduction of IFN-γ, suggesting that HTLV-1 may intracellularly induce T cell plasticity from Treg to IFN-γ+ T cells. This review examines the recent research into the association between HTLV-1 and Treg cells that has greatly enhanced understanding of the pathogenic mechanisms underlying immune dysregulation in HTLV-1-associated neuroinflammatory disease.

  10. Defective human T-cell lymphotropic virus type I (HTLV-I) provirus in seronegative tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM) patients.

    Science.gov (United States)

    Ramirez, E; Fernandez, J; Cartier, L; Villota, C; Rios, M

    2003-02-01

    Infection with human T-cell lymphotropic virus type I (HTLV-I) have been associated with the development of the tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM). We studied the presence of HTLV-I provirus in peripheral blood mononuclear cells (PBMC) from 72 Chilean patients with progressive spastic paraparesis by polymerase chain reaction: 32 seropositive and 40 seronegative cases. We amplified different genomic regions of HTLV-I using primers of 5' ltr, tax, env/tax, pX, pol and env genes. These genes were detected from all seropositive patients. The seronegative patients were negative with 5' ltr, pol, env, and pX primers. However, amplified product of tax and env/tax genes was detected from 16 and four seronegative patients, respectively. Three of them were positive with both genetic regions. The results of this study show that the complete HTLV-I provirus is found in 100% of seropositive cases. In seronegative cases, clinically very similar of seropositive cases, was found only tax gene in 42.5% (17/40) of patients. These results suggest the presence of a defective HTLV-I provirus in some seronegative patients with progressive spastic paraparesis, and suggest a pathogenic role of this truncate provirus for a group of TSP/HAM. PMID:12573502

  11. Inferences about the global scenario of human T-cell lymphotropic virus type 1 infection using data mining of viral sequences

    Directory of Open Access Journals (Sweden)

    Thessika Hialla Almeida Araujo

    2014-07-01

    Full Text Available Human T-cell lymphotropic virus type 1 (HTLV-1 is mainly associated with two diseases: tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM and adult T-cell leukaemia/lymphoma. This retrovirus infects five-10 million individuals throughout the world. Previously, we developed a database that annotates sequence data from GenBank and the present study aimed to describe the clinical, molecular and epidemiological scenarios of HTLV-1 infection through the stored sequences in this database. A total of 2,545 registered complete and partial sequences of HTLV-1 were collected and 1,967 (77.3% of those sequences represented unique isolates. Among these isolates, 93% contained geographic origin information and only 39% were related to any clinical status. A total of 1,091 sequences contained information about the geographic origin and viral subtype and 93% of these sequences were identified as subtype “a”. Ethnicity data are very scarce. Regarding clinical status data, 29% of the sequences were generated from TSP/HAM and 67.8% from healthy carrier individuals. Although the data mining enabled some inferences about specific aspects of HTLV-1 infection to be made, due to the relative scarcity of data of available sequences, it was not possible to delineate a global scenario of HTLV-1 infection.

  12. Occult persistence and lymphotropism of hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    Tram NQ Pham; Tomasz I Michalak

    2008-01-01

    Recent discovery of occult hepatitis C virus (HCV)infection persisting after spontaneous or antiviral therapy-induced resolution of hepatitis C was made possible by the introduction of nucleic acid amplification assays capable of detecting HCV RNA at sensitivities superseding those offered by clinical tests. Although individuals with this seemingly silent HCV infection are usually anti-HCV antibody reactive and have normal liver function tests, occult HCV infection has also been reported in anti-HCV-negative individuals with persistently elevated liver enzymes of unknown etiology. Studies have shown that HCV RNA can persist for years in serum, iymphomononuciear cells and liver in the absence of clinical symptoms, although histological evidence of a mild inflammatory liver injury can be occasionally encountered. Furthermore, while HCV RNA can be detected in circulating lymphoid cells in approximately 30% of cases, a short-term culture under stimulatory conditions augments HCV replication in these cells allowing detection of virus in otherwise HCV-negative cases. HCV infects different immune cell subsets, including CD4+ and CD8+ T lymphocytes, B cells and monocytes. Studies employing cional sequencing and single-stranded conformational polymorphism analyses have revealed unique HCV variants residing in immune cells, further strengthening the notion of HCV lymphotropism. Overall, the data accumulated suggest that occult HCV infection is a common consequence of resolution of symptomatic hepatitis C and that examination of the cells of the immune system is an effective approach to diagnosis of HCV infection and its long-term persistence. Further work is required to fully realize pathogenic and epidemiological consequences of occult HCV persistence.

  13. Seroprevalence of human T-cell lymphotropic virus-1/2 in blood donors in northern pakistan: implication for blood donor screening

    International Nuclear Information System (INIS)

    To determine the seroprevalence of Human T-cell Lymphotropic Virus-1/2 (HTLV-1/2) in blood donors in Northern Pakistan. Study Design: Descriptive study. Place and Duration of Study: Armed Forces Institute of Transfusion, Rawalpindi, from July to August 2013. Methodology:A total of 2100 blood donors were screened for anti-HTLV-1/2 antibodies during the study period, in a pool of six, on a highly sensitive, Chemiluminiscent Microparticle Immunoassay (CMIA) based system. The screening test reactive donors were recalled, counseled and interviewed, and a fresh sample was obtained for confirmatory testing. Confirmation was performed using additional immunoassays including Line Immunoassay (LIA); with additional testing for HTLV-1 pvDNAPCR. Frequency and percentages were determined. Results: Four donors (0.19%) were repeatedly screening test-reactive and were subsequently confirmed to be HTLV-1 infected by line immunoassay and HTLV-1 pvDNAPCR. All four donors were male with mean age of 27 ± 6.27 years. Two (50%) of the positive donors gave history of Multiple Sexual Partners (MSP). Conclusion: HTLV-1 seroprevalence in Northern Pakistan blood donors was determined to be 0.19%. Large scale studies, including the cost effectiveness of screening blood donations for anti-HTLV-1/2 in Pakistan, are recommended. (author)

  14. Human T-cell lymphotropic virus type 1-infected T lymphocytes impair catabolism and uptake of glutamate by astrocytes via Tax-1 and tumor necrosis factor alpha.

    Science.gov (United States)

    Szymocha, R; Akaoka, H; Dutuit, M; Malcus, C; Didier-Bazes, M; Belin, M F; Giraudon, P

    2000-07-01

    Human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of a chronic progressive myelopathy called tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM). In this disease, lesions of the central nervous system (CNS) are associated with perivascular infiltration by lymphocytes. We and others have hypothesized that these T lymphocytes infiltrating the CNS may play a prominent role in TSP/HAM. Here, we show that transient contact of human or rat astrocytes with T lymphocytes chronically infected by HTLV-1 impairs some of the major functions of brain astrocytes. Uptake of extracellular glutamate by astrocytes was significantly decreased after transient contact with infected T cells, while the expression of the glial transporters GLAST and GLT-1 was decreased. In two-compartment cultures avoiding direct cell-to-cell contact, similar results were obtained, suggesting possible involvement of soluble factors, such as cytokines and the viral protein Tax-1. Recombinant Tax-1 and tumor necrosis factor alpha (TNF-alpha) decreased glutamate uptake by astrocytes. Tax-1 probably acts by inducing TNF-alpha, as the effect of Tax-1 was abolished by anti-TNF-alpha antibody. The expression of glutamate-catabolizing enzymes in astrocytes was increased for glutamine synthetase and decreased for glutamate dehydrogenase, the magnitudes of these effects being correlated with the level of Tax-1 transcripts. In conclusion, Tax-1 and cytokines produced by HTLV-1-infected T cells impair the ability of astrocytes to manage the steady-state level of glutamate, which in turn may affect neuronal and oligodendrocytic functions and survival. PMID:10864655

  15. Risk Factors for Human T Cell Lymphotropic Virus Type I among Injecting Drug Users in Northeast Brazil: Possibly Greater Efficiency of Male to Female Transmission

    Directory of Open Access Journals (Sweden)

    Dourado Inês

    1999-01-01

    Full Text Available It was observed in the city of Salvador, State of Bahia, the highest seroprevalence of human T cell lymphotropic virus type 1 (HTLV-I infection in Brazil as demonstrated by national wide blood bank surveys. In this paper, we report results of an investigation of drug use and sexual behavior associated with HTLV-I infection among male and female injecting drug users (IDUs in Salvador. A cross sectional study was conducted in the Historical District of Salvador from 1994-1996 (Projeto Brasil-Salvador and 216 asymptomatic IDUs were selected using the snowball contact technique. Blood samples were collected for serological assays. Sera were screened for human immunodeficiency virus (HIV-1/2 and HTLV-I/II antibodies by ELISA and confirmed by Western blot. The overall prevalence of HTLV-I/II was 35.2% (76/216. The seroprevalence of HTLV-I, HTLV-II and HIV-1 was for males 22%, 11.3% and 44.1% and for females 46.2%, 10.3% and 74.4% respectively. HTLV-I was identified in 72.4% of HTLV positive IDUs. Variables which were significantly associated with HTLV-I infection among males included needle sharing practices, duration of injecting drug use, HIV-1 seropositivity and syphilis. Among women, duration of injecting drug use and syphilis were strongly associated with HTLV-I infection. Multivariate analysis did not change the direction of these associations. Sexual intercourse might play a more important role in HTLV-I infection among women than in men.

  16. Human T cell lymphotropic virus type I genomic expression and impact on intracellular signaling pathways during neurodegenerative disease and leukemia.

    Science.gov (United States)

    Yao, J; Wigdahl, B

    2000-01-01

    HTLV-I has been identified as the etiologic agent of neoplasia within the human peripheral blood T lymphocyte population, and a progressive neurologic disorder based primarily within the central nervous system. We have examined the role of HTLV-I in these two distinctly different clinical syndromes by examining the life cycle of the virus, with emphasis on the regulation of viral gene expression within relevant target cell populations. In particular, we have examined the impact of specific viral gene products, particularly Tax, on cellular metabolic function. Tax is a highly promiscuous and pleiotropic viral oncoprotein, and is the most important factor contributing to the initial stages of viral-mediated transformation of T cells after HTLV-I infection. Tax, which weakly binds to Tax response element 1 (TRE-1) in the viral long terminal repeat (LTR), can dramatically trans-activate viral gene expression by interacting with cellular transcription factors, such as activated transcription factors and cyclic AMP response element binding proteins (ATF/CREB), CREB binding protein (CBP/p300), and factors involved with the basic transcription apparatus. At the same time, Tax alters cellular gene expression by directly or indirectly interacting with a variety of cellular transcription factors, cell cycle control elements, and cellular signal transduction molecules ultimately resulting in dysregulated cell proliferation. The mechanisms associated with HTLV-I infection, leading to tropical spastic paraparesis (TSP) are not as clearly resolved. Possible explanations of viral-induced neurologic disease range from central nervous system (CNS) damage caused by direct viral invasion of the CNS to bystander CNS damage caused by the immune response to HTLV-I infection. It is interesting to note that it is very rare for an HTLV-I infected individual to develop both adult T cell leukemia (ATL) and TSP in his/her life time, suggesting that the mechanisms governing development of these

  17. Effect of p40tax trans-activator of human T cell lymphotropic virus type I on expression of autoantigens.

    Science.gov (United States)

    Banki, K; Ablonczy, E; Nakamura, M; Perl, A

    1994-03-01

    The possibility of a retroviral etiology has long been raised in a number of autoimmune disorders. More recently, Sjögren's syndrome and rheumatoid arthritis were noted in transgenic mice carrying the tax gene of human T cell leukemia virus type I (HTLV-I). To evaluate the involvement of HTLV-I Tax in autoimmunity, its effect on expression of autoantigens was investigated. A metallothionein promoter-driven p40tax expression plasmid, pMAXRHneo-1, was stably transfected into Molt4 and Jurkat cells and the p40tax protein was induced with CdCl2. trans-Activation or trans-repression of autoantigens by HTLV-I Tax was studied by Western blot analysis utilizing autoantigen-specific murine monoclonal and rabbit polyvalent antibodies as well as sera from 161 autoimmune patients. Induction of p40tax of HTLV-I had no significant effect on levels of expression of common autoantigens U1 snRNP, Sm, Ro, La, HSP-70, topoisomerase I/Scl70, PCNA, and HRES-1. Expression of two potentially novel autoantigens, 44 and 46 kDa, was induced by p40tax as detected by sera of progressive systemic sclerosis patients, BAK and VAR. By contrast, expression of 24- and 34-kDa proteins was suppressed in response to induction of p40tax as detected by sera of systemic lupus erythematosus patients PUS and HOR. Because none of these patients were infected by HTLV-I, a protein functionally similar to p40tax may be involved in eliciting autoantigen expression and a subsequent autoantibody response in a minority of patients with PSS and SLE. Sera of autoimmune patients may also be utilized to detect novel proteins trans-activated or trans-repressed by p40tax of HTLV-I. PMID:8018391

  18. Factors secreted by human T lymphotropic virus type I (HTLV-I)-infected cells can enhance or inhibit replication of HIV-1 in HTLV-I-uninfected cells: implications for in vivo coinfection with HTLV-I and HIV-1.

    Science.gov (United States)

    Moriuchi, H; Moriuchi, M; Fauci, A S

    1998-05-18

    It remains controversial whether human T lymphotropic virus type I (HTLV-I) coinfection leads to more rapid progression of human immunodeficiency virus (HIV) disease in dually infected individuals. To investigate whether HTLV-I infection of certain cells can modulate HIV-1 infection of surrounding cells, primary CD4(+) T cells were treated with cell-free supernatants from HTLV-I-infected MT-2 cell cultures. The primary CD4+ T cells became resistant to macrophage (M)-tropic HIV-1 but highly susceptible to T cell (T)-tropic HIV-1. The CC chemokines RANTES (regulated on activation, normal T cell expressed and secreted), macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta in the MT-2 cell supernatants were identified as the major suppressive factors for M-tropic HIV-1 as well as the enhancers of T-tropic HIV-1 infection, whereas soluble Tax protein increased susceptibility to both M- and T-tropic HIV-1. The effect of Tax or CC chemokines on T-tropic HIV-1 was mediated, at least in part, by increasing HIV Env-mediated fusogenicity. Our data suggest that the net effect of HTLV-I coinfection in HIV-infected individuals favors the transition from M- to T-tropic HIV phenotype, which is generally indicative of progressive HIV disease. PMID:9584147

  19. Anti-Human T-Lymphotropic Virus Type-I Antibodies in Atomic-Bomb Survivors

    OpenAIRE

    Matsuo, Tatsuki; Nakashima, Eiji; Carter, Randolph L.; Neriishi, Kazuo; Mabuchi, Kiyohiko; Akiyama, Mitoshi; Shimaoka, Katsutaro; Kinoshita, Ken-Ichiro; Tomonaga, Masao; Ichimaru, Michito

    1995-01-01

    Adult T-cell leukemia (ATL), induced by human T-lymphotropic virus type-I (HTLV-I), is endemic in Nagasaki, Japan. To investigate the effects of atomic-bomb radiation on development of this specific type of leukemia, 6182 individuals in the Radiation Effects Research Foundation (RERE) Adult Health Study sample in Hiroshima and Nagasaki were examined for positive rate of HTLV-I antibody. Several lymphocyte parameters were also studied for 70 antibody-positive subjects in Nagasaki. The HTLV-I a...

  20. Demonstration of human T lymphotropic virus type I (HTLV-I)-specific T cell responses from seronegative and polymerase chain reaction-negative persons exposed to HTLV-I.

    Science.gov (United States)

    Nishimura, M; Kermode, A G; Clerici, M; Shearer, G M; Berzofsky, J A; Uchiyama, T; Wiktor, S Z; Pate, E; Maloney, B; Manns, A

    1994-08-01

    Human T lymphotropic virus type I (HTLV-I) is a human retrovirus etiologically linked to adult T cell leukemia and the progressive chronic neurologic disease HTLV-I-associated myelopathy/tropical spastic paraparesis. Described is a method that measures the production of interleukin-2 from HTLV-I synthetic peptide-stimulated peripheral blood lymphocytes (PBL) of HTLV-I-infected persons. The peptides correspond to immunogenic regions of the HTLV-I Env and Tax proteins. Significantly, this assay demonstrated T cell responses to these HTLV-I peptides from coded PBL samples in 7 of 19 HTLV-I-seronegative polymerase chain reaction-negative persons known to have been exposed to HTLV-I but in none of 16 matched controls without risk factors for exposure (P = .007). The implications of this finding are discussed. PMID:8035019

  1. Direct analysis of viral-specific CD8+ T cells with soluble HLA-A2/Tax11-19 tetramer complexes in patients with human T cell lymphotropic virus-associated myelopathy.

    Science.gov (United States)

    Bieganowska, K; Höllsberg, P; Buckle, G J; Lim, D G; Greten, T F; Schneck, J; Altman, J D; Jacobson, S; Ledis, S L; Hanchard, B; Chin, J; Morgan, O; Roth, P A; Hafler, D A

    1999-02-01

    Human T cell lymphotropic virus-I (HTLV-I)-associated myelopathy is a slowly progressive neurologic disease characterized by inflammatory infiltrates in the central nervous system accompanied by clonal expansion of HTLV-I-reactive CD8+ T-cells. In patients carrying the HLA-A2 allele, the immune response is primarily directed to the Tax11-19 peptide. The frequency, activation state, and TCR usage of HLA-A2/Tax11-19 binding T cells in patients with HTLV-I-associated myelopathy was determined using MHC class I tetramers loaded with the Tax11-19 peptide. Circulating Tax11-19-reactive T cells were found at very high frequencies, approaching 1:10 circulating CD8+ T cells. T cells binding HLA-A2/Tax11-19 consisted of heterogeneous populations expressing different chemokine receptors and the IL-2R beta-chain but not the IL-2R alpha-chain. Additionally, Tax11-19-reactive CD8+ T cells used one predominant TCR Vbeta-chain for the recognition of the HLA-A2/Tax11-19 complex. These data provide direct evidence for high frequencies of circulating Tax11-19-reactive CD8+ T cells in patients with HTLV-I-associated myelopathy. PMID:9973440

  2. Differential activation of proliferation and cytotoxicity in human T-cell lymphotropic virus type I Tax-specific CD8 T cells by an altered peptide ligand.

    OpenAIRE

    Höllsberg, P; Weber, W E; Dangond, F; Batra, V; Sette, A.; Hafler, D A

    1995-01-01

    Human T-cell leukemia virus type I (HTLV-I) gives rise to a neurologic disease known as HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Although the pathogenesis of the disease is unknown, the presence of a remarkably high frequency of Tax-specific, cytotoxic CD8 T cells may suggest a role of these cells in the development of HAM/TSP. Antigen-mediated signaling in a CD8 T-cell clone specific for the Tax(11-19) peptide of HTLV-I was studied using analog peptides substitute...

  3. "Signal-on" photoelectrochemical biosensor for sensitive detection of human T-Cell lymphotropic virus type II DNA: dual signal amplification strategy integrating enzymatic amplification with terminal deoxynucleotidyl transferase-mediated extension.

    Science.gov (United States)

    Shen, Qingming; Han, Li; Fan, Gaochao; Zhang, Jian-Rong; Jiang, Liping; Zhu, Jun-Jie

    2015-01-01

    A novel "signal-on" photoelectrochemical (PEC) biosensor for sensitive detection of human T-cell lymphotropic virus type II (HTLV-II) DNA was developed on the basis of enzymatic amplification coupled with terminal deoxynucleotidyl transferase (TdT)-mediated extension strategy. The intensity of the photocurrent signal was proportional to the concentration of the HTLV-II DNA-target DNA (tDNA) by dual signal amplification. In this protocol, GR-CdS:Mn/ZnS nanocomposites were used as photoelectric conversion material, while pDNA was used as the tDNA recognizing unit. Moreover, the TdT-mediated extension and the enzymatic signal amplification technique were used to enhance the sensitivity of detection. Using this novel dual signal amplification strategy, the prototype of PEC DNA sensor can detect as low as ∼0.033 fM of HTLV-II DNA with a linear range of 0.1-5000 fM, with excellent differentiation ability even for single-base mismatches. This PEC DNA assay opens a promising platform to detect various DNA targets at ultralow levels for early diagnoses of different diseases. PMID:25871300

  4. Tax secretion from peripheral blood mononuclear cells and Tax detection in plasma of patients with human T-lymphotropic virus-type 1-associated myelopathy/tropical spastic paraparesis and asymptomatic carriers.

    Science.gov (United States)

    Medina, Fernando; Quintremil, Sebastián; Alberti, Carolina; Godoy, Fabián; Pando, María E; Bustamante, Andrés; Barriga, Andrés; Cartier, Luis; Puente, Javier; Tanaka, Yuetsu; Valenzuela, María A; Ramírez, Eugenio

    2016-03-01

    Human T-lymphotropic virus-type 1 (HTLV-1) is the etiologic agent of the neurologic disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Tax viral protein plays a critical role in viral pathogenesis. Previous studies suggested that extracellular Tax might involve cytokine-like extracellular effects. We evaluated Tax secretion in 18 h-ex vivo peripheral blood mononuclear cells (PBMCs) cultures from 15 HAM/TSP patients and 15 asymptomatic carriers. Futhermore, Tax plasma level was evaluated from other 12 HAM/TSP patients and 10 asymptomatic carriers. Proviral load and mRNA encoding Tax were quantified by PCR and real-time RT-PCR, respectively. Intracellular Tax in CD4(+)CD25(+) cells occurred in 100% and 86.7% of HAM/TSP patients and asymptomatic carriers, respectively. Percentage of CD4(+)CD25(+) Tax+, proviral load and mRNA encoding Tax were significantly higher in HAM/TSP patients. Western blot analyses showed higher secretion levels of ubiquitinated Tax in HAM/TSP patients than in asymptomatic carriers. In HTLV-1-infected subjects, Western blot of plasma Tax showed higher levels in HAM/TSP patients than in asymptomatic carriers, whereas no Tax was found in non-infected subjects. Immunoprecipitated plasma Tax resolved on SDS-PAGE gave two major bands of 57 and 48 kDa allowing identification of Tax and Ubiquitin peptides by mass spectrometry. Relative percentage of either CD4(+)CD25(+) Tax+ cells, or Tax protein released from PBMCs, or plasma Tax, correlates neither with tax mRNA nor with proviral load. This fact could be explained by a complex regulation of Tax expression. Tax secreted from PBMCs or present in plasma could potentially become a biomarker to distinguish between HAM/TSP patients and asymptomatic carriers. PMID:26241614

  5. Functional changes in astrocytes by human T-lymphotropic virus type-1 T-lymphocytes.

    Science.gov (United States)

    Akaoka, H; Szymocha, R; Beurton-Marduel, P; Bernard, A; Belin, M F; Giraudon, P

    2001-10-30

    The human T-lymphotropic virus type-1 (HTLV-1) is the causative agent of a chronic progressive myelopathy (TSP/HAM) in which lesions of the central nervous system (CNS) are associated with infiltration of HTLV-1-infected T-cells. In a model that mimics the interaction between glial and T-cells, we show that transient contact with T-lymphocytes chronically infected with HTLV-1 induce profound metabolic alterations in astrocytes. Within the first week post-contact, an overall activation of astrocyte metabolism was observed as assessed by enhanced uptake of glutamate and glucose, and lactate release. In contrast, longer examination showed a reduced astrocytic accumulation of glutamate. The time course of the change in glutamate uptake was in fact biphasic. Previous observations indicated that HTLV-1 protein Tax-1 was involved in this delayed decrease, via the induction of TNF-alpha. The expression of the glial glutamate transporters, GLAST and GLT-1 decreased in parallel. These decreases in glutamate uptake and transporters' expression were associated with an imbalance in the expression of the catabolic enzymes of glutamate, GS and GDH, presumably due to Tax-1. Given the fact that impairment of glutamate management in astrocytes is able to compromise the functional integrity of neurons and oligodendrocytes, our results altogether give new insights into the physiopathology of TSP/HAM. PMID:11520580

  6. NF-kappa B activity in T cells stably expressing the Tax protein of human T cell lymphotropic virus type I

    Energy Technology Data Exchange (ETDEWEB)

    Lacoste, J.; Cohen, L.; Hiscott, J. (Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec (Canada))

    1991-10-01

    The effect of constitutive Tax expression on the interaction of NF-{kappa} B with its recognition sequence and on NF-{kappa} B-dependent gene expression was examined in T lymphoid Jurkat cell lines (19D and 9J) stably transformed with a Tax expression vector. Tax expressing T cell lines contained a constitutive level of NF-{kappa} B binding activity, detectable by mobility shift assay and uv cross-linking using a palindromic NF-{kappa} B probe homologous to the interferon beta PRDII site. In Jurkat and NC2.10 induction with phorbol esters resulted in the appearance of new DNA binding proteins of 85, 75, and 54 kDa, whereas in Tax expressing cells the 85-kDa protein and a 92-kDa DNA binding protein were constitutively induced. Expression of Tax protein in 19D and 9J resulted in transcription of the endogenous NF-kappa B-dependent granulocyte-macrophage colony stimulating factor gene and increased basal level expression of transfected NF-kappa B-regulated promoters. Nonetheless transcription of both the endogenous and the transfected gene was inducible by PMA treatment. Tax expression in Jurkat T cells may alter the stoichiometry of NF-kappa B DNA binding proteins and thus change the expression of NF-kappa B-regulated promoters.

  7. Selective expression of a protein-tyrosine kinase, p56lyn, in hematopoietic cells and association with production of human T-cell lymphotropic virus type I

    International Nuclear Information System (INIS)

    This paper reports the identification of the lyn gene product, a member of the src-related family of protein-tyrosine kinases, and its expression in hematopoietic cells. A lyn-specific sequence (Arg-25 to Ala-119 of the protein) was expressed in Escherichia coli as a fusion protein with β-galactosidase. Antiserum raised against the fusion protein immunoprecipitated a 56-kDa protein from human B lymphocytes. Incubation of the immunoprecipitate with [γ-32P]ATP resulted in the phosphorylation of this protein at tyrosine residues. Immunohistological and immunoblotting analyses showed that the lyn gene product was expressed in lymphatic tissues (spleen and tonsil) and in adult lung, which contains many macrophages. Furthermore, both the transcripts and the protein products of the lyn gene accumulated in macrophages/monocytes, platelets, and B lymphocytes but were not expressed appreciably in granulocytes, erythrocytes, or T lymphocytes, suggesting that lyn gene products function primarily in certain differentiated cells of lymphoid and myeloid lineages

  8. Anti-human T-lymphotropic virus type-I antibodies in atomic-bomb survivors

    International Nuclear Information System (INIS)

    Adult T-cell leukemia (ATL), induced by human T-lymphotropic virus type-I (HTLV-I), is endemic in Nagasaki, Japan. To investigate the effects of atomic-bomb radiation on development of this specific type of leukemia, 6182 individuals in the Radiation Effects Research Foundation (RERF) Adult Health Study sample in Hiroshima and Nagasaki were examined for positive rate of HTLV-I antibody. Several lymphocyte parameters were also studied for 70 antibody-positive subjects in Nagasaki. The HTLV-I antibody-positive rate was higher in Nagasaki (6.36%) than in Hiroshima (0.79%) and significantly increased with increasing age, but no association was observed with radiation dose. Whether relationship existed between antibody titer levels and radiation dose among antibody-positive subjects was not clear. The frequency of abnormal lymphocytes tended to be higher in antibody-positive subjects than in antibody-negative subjects, and higher in females than in males regardless of radiation dose. The lymphocyte count was lower in antibody-positive subjects than in antibody-negative subjects and lower in female than in male subjects. No evidence was found to suggest that atomic-bomb radiation plays an important role in HTLV-I infection. (author)

  9. A Caucasian Australian presenting with human T-lymphotropic virus type I associated myelopathy: a case report

    Science.gov (United States)

    2014-01-01

    Introduction We report the first known case of human T-lymphotropic virus type I associated myelopathy/tropical spastic paraparesis in an Australian Caucasian, a disease reported in Aboriginal and immigrant populations where the virus is often endemic. Case presentation A 41-year-old Caucasian Australian man had a 3-year background of progressive functional decline from a myelopathy with spastic paraparesis and sphincteric dysfunction. Conclusions Although studies have shown a very low prevalence of human T-lymphotropic virus type I in the greater Australian population, increased focus on Aboriginal health, and the expanding diversity and integration of the Australian population means that presentation of human T-lymphotropic virus type I-associated disease is likely to increase. PMID:25416840

  10. Lymphotropism and host responses during acute wild-type canine distemper virus infections in a highly susceptible natural host

    DEFF Research Database (Denmark)

    Nielsen, Line; Søgaard, Mette; Jensen, Trine Hammer;

    2009-01-01

    The mechanisms behind the in vivo virulence of immunosuppressive wild-type Morbillivirus infections are still not fully understood. To investigate lymphotropism and host responses we have selected the natural host model of canine distemper virus (CDV) infection in mink. This model displays...

  11. HUMAN T-LYMPHOTROPIC VIRUS 1 (HTLV-1) AND HUMAN T-LYMPHOTROPIC VIRUS 2 (HTLV-2): GEOGRAPHICAL RESEARCH TRENDS AND COLLABORATION NETWORKS (1989-2012)

    Science.gov (United States)

    GONZÁLEZ-ALCAIDE, Gregorio; RAMOS, José Manuel; HUAMANÍ, Charles; de MENDOZA, Carmen; SORIANO, Vicent

    2016-01-01

    Publications are often used as a measure of research work success. Human T-lymphotropic virus (HTLV) type 1 and 2 are human retroviruses, which were discovered in the early 1980s, and it is estimated that 15-20 million people are infected worldwide. This article describes a bibliometric review and a coauthorship network analysis of literature on HTLV indexed in PubMed in a 24-year period. A total of 7,564 documents were retrieved, showing a decrease in the number of documents from 1996 to 2007. HTLV manuscripts were published in 1,074 journals. Japan and USA were the countries with the highest contribution in this field (61%) followed by France (8%). Production ranking changed when the number of publications was normalized by population (Dominican Republic and Japan), by gross domestic product (Guinea-Bissau and Gambia), and by gross national income per capita (Brazil and Japan). The present study has shed light on some of the defining features of scientific collaboration performed by HTLV research community, such as the existence of core researchers responsible for articulating the development of research in the area, facilitating wider collaborative relationships and the integration of new authors in the research groups. PMID:26910450

  12. HUMAN T-LYMPHOTROPIC VIRUS 1 (HTLV-1) AND HUMAN T-LYMPHOTROPIC VIRUS 2 (HTLV-2): GEOGRAPHICAL RESEARCH TRENDS AND COLLABORATION NETWORKS (1989-2012).

    Science.gov (United States)

    González-Alcaide, Gregorio; Ramos, José Manuel; Huamaní, Charles; Mendoza, Carmen de; Soriano, Vicent

    2016-01-01

    Publications are often used as a measure of research work success. Human T-lymphotropic virus (HTLV) type 1 and 2 are human retroviruses, which were discovered in the early 1980s, and it is estimated that 15-20 million people are infected worldwide. This article describes a bibliometric review and a coauthorship network analysis of literature on HTLV indexed in PubMed in a 24-year period. A total of 7,564 documents were retrieved, showing a decrease in the number of documents from 1996 to 2007. HTLV manuscripts were published in 1,074 journals. Japan and USA were the countries with the highest contribution in this field (61%) followed by France (8%). Production ranking changed when the number of publications was normalized by population (Dominican Republic and Japan), by gross domestic product (Guinea-Bissau and Gambia), and by gross national income per capita (Brazil and Japan). The present study has shed light on some of the defining features of scientific collaboration performed by HTLV research community, such as the existence of core researchers responsible for articulating the development of research in the area, facilitating wider collaborative relationships and the integration of new authors in the research groups. PMID:26910450

  13. NLRP3 polymorphism is associated with protection against human T-lymphotropic virus 1 infection

    Directory of Open Access Journals (Sweden)

    Anselmo Jiro Kamada

    2014-11-01

    Full Text Available Inter-individual heterogeneity in the response to human T-lymphotropic virus 1 (HTLV-1 infection has been partially attributed to host genetic background. The antiviral activity of the inflammasome cytoplasmic complex recognises viral molecular patterns and regulates immune responses via the activation of interleukin (IL-1 family (IL-1, IL-18 and IL-33 members. The association between polymorphisms in the inflammasome receptors NLRP1 and NLRP3 and HTLV-1 infection was evaluated in a northeastern Brazilian population (84 HTLV-1 carriers and 155 healthy controls. NLRP3 rs10754558 G/G was associated with protection against HTLV-1 infection (p = 0.012; odds ratio = 0.37. rs10754558 affects NLRP3 mRNA stability; therefore, our results suggest that higher NLRP3 expression may augment first-line defences, leading to the effective protection against HTLV-1 infection.

  14. Human T-lymphotropic virus type II infection in Vietnamese thalassemic patients.

    Science.gov (United States)

    Lin, M T; Nguyen, B T; Binh, T V; Be, T V; Chiang, T Y; Tseng, L H; Yang, Y C; Lin, K H; Chen, Y C

    1997-01-01

    Anti-human T-lymphotropic virus type I/II (HTLV-I/II) antibodies were screened by particle agglutination test in a total of 66 patients with thalassemia major who received multiple transfusion from paid donors at the Blood Transfusion Hematology Center of Ho Chi Minh City in South Vietnam. HTLV-II infection was confirmed in 6 patients (9.1%) by Western blot analysis and/or polymerase chain reaction. Phylogenetic analysis revealed that long terminal repeat sequences of HTLV-II proviruses from 5 thalassemic patients in Vietnam belonged to the same phylogenetic subgroup of HTLV-IIb as those from intravenous drug abusers in North America and Europe. These data shed light on the route of introducing HTLV-II into Vietnam. PMID:9267453

  15. Human T-lymphotropic virus type I-associated myelopathy and tax gene expression in CD4+ T lymphocytes.

    Science.gov (United States)

    Moritoyo, T; Reinhart, T A; Moritoyo, H; Sato, E; Izumo, S; Osame, M; Haase, A T

    1996-07-01

    Infection by human T-lymphotropic virus type I (HTLV-I) is associated with adult T-cell leukemia and a slowly progressive disease of the central nervous system (CNS), HTLV-I-associated myelopathy/tropical spastic paraparesis, characterized pathologically by inflammation and white matter degeneration in the spinal cord. One of the explanations for the tissue destruction is that HTLV-I infects cells in the CNS, or HTLV-I-infected CD4+ T lymphocytes enter the CNS, and this drives local expansion of virus-specific CD8+ cytotoxic T lymphocytes, which along with cytokines cause the pathological changes. Because both in the circulation and in the cerebrospinal fluid, CD8+ cytotoxic T lymphocytes are primarily reactive to the product of the HTLV-I tax gene, we sought evidence of expression of this gene within cells in the inflammatory lesions. After using double-label in situ hybridization techniques, we now report definitive localization of HTLV-I tax gene expression in CD4+ T lymphocytes in areas of inflammation and white matter destruction. These findings lend support to a hypothetical scheme of neuropathogenesis in which HTLV-I tax gene expression provokes and sustains an immunopathological process that progressively destroys myelin and axons in the spinal cord. PMID:8687197

  16. Long Terminal Repeat Circular DNA as Markers of Active Viral Replication of Human T Lymphotropic Virus-1 in Vivo.

    Science.gov (United States)

    Fox, James M; Hilburn, Silva; Demontis, Maria-Antonietta; Brighty, David W; Rios Grassi, Maria Fernanda; Galvão-Castro, Bernardo; Taylor, Graham P; Martin, Fabiola

    2016-03-01

    Clonal expansion of human T-lymphotropic virus type-1 (HTLV-1) infected cells in vivo is well documented. Unlike human immunodeficiency virus type 1 (HIV-1), HTLV-1 plasma RNA is sparse. The contribution of the "mitotic" spread of HTLV-1 compared with infectious spread of the virus to HTLV-1 viral burden in established infection is uncertain. Since extrachromosomal long terminal repeat (LTR) DNA circles are indicators of viral replication in HIV-1 carriers with undetectable plasma HIV RNA, we hypothesised that HTLV-1 LTR circles could indicate reverse transcriptase (RT) usage and infectious activity. 1LTR and 2LTR DNA circles were measured in HTLV-1 cell lines and peripheral blood mononuclear cells (PBMC) of asymptomatic carriers (ACs) and patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) or adult T cell leukaemia/lymphoma (ATLL). 1LTR DNA circles were detected in 14/20 patients at a mean of 1.38/100 PBMC but did not differentiate disease status nor correlate with HTLV-1 DNA copies. 2LTR DNA circles were detected in 30/31 patients and at higher concentrations in patients with HTLV-1-associated diseases, independent of HTLV-1 DNA load. In an incident case the 2LTR DNA circle concentration increased 2.1 fold at the onset of HAM/TSP compared to baseline. Detectable and fluctuating levels of HTLV-1 DNA circles in patients indicate viral RT usage and virus replication. Our results indicate HTLV-1 viral replication capacity is maintained in chronic infection and may be associated with disease onset. PMID:26985903

  17. Cell-type-specific control elements of the lymphotropic papovavirus enhancer.

    OpenAIRE

    Erselius, J R; Jostes, B; Hatzopoulos, A K; Mosthaf, L; Gruss, P

    1990-01-01

    Lymphotropic papovavirus (LPV) exhibits a highly restricted host range, in which only cells of primate B-lymphocyte origin are permissive for infection. Its enhancer element contributes to this tropism, since transcriptional potentiation is confined to cells of the hematopoietic lineage. Nuclear extracts from B and T cells, but not from HeLa cells, contain protein factors that interact specifically with the LPV 63-base-pair enhancer repeat, as demonstrated by DNase I footprinting and gel reta...

  18. Clinical pathophysiology of human T-lymphotropic virus-type1-associated myelopathy/tropical spastic paraparesis

    Directory of Open Access Journals (Sweden)

    YoshihisaYamano

    2012-11-01

    Full Text Available Human T-lymphotropic virus type 1 (HTLV-1, a human retrovirus, is the causative agent of a progressive neurological disease termed HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP. HAM/TSP is a chronic inflammatory disease of the central nervous system and is characterized by unremitting myelopathic symptoms such as spastic paraparesis, lower limb sensory disturbance, and bladder/bowel dysfunction. Approximately 0.25%–3.8% of HTLV-1-infected individuals develop HAM/TSP, which is more common in women than in men. Since the discovery of HAM/TSP, significant advances have been made with respect to elucidating the virological, molecular, and immunopathological mechanisms underlying this disease. These findings suggest that spinal cord invasion by HTLV-1-infected T cells triggers a strong virus-specific immune response and increases proinflammatory cytokine and chemokine production, leading to chronic lymphocytic inflammation and tissue damage in spinal cord lesions. However, little progress has been made in the development of an optimal treatment for HAM/TSP, more specifically in the identification of biomarkers for predicting disease progression and of molecular targets for novel therapeutic strategies targeting the underlying pathological mechanisms. This review summarizes current clinical and pathophysiological knowledge on HAM/TSP and discusses future focus areas for research on this disease.

  19. Molecular epidemiology of endemic human T-lymphotropic virus type 1 in a rural community in Guinea-Bissau.

    Directory of Open Access Journals (Sweden)

    Carla van Tienen

    Full Text Available Human T-Lymphotropic Virus Type 1 (HTLV-1 infection causes lethal adult T-cell leukemia (ATL and severely debilitating HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP in up to 5% of infected adults. HTLV-1 is endemic in parts of Africa and the highest prevalence in West Africa (5% has been reported in Caio, a rural area in the North-West of Guinea-Bissau. It is not known which HTLV-1 variants are present in this community. Sequence data can provide insights in the molecular epidemiology and help to understand the origin and spread of HTLV-1.To gain insight into the molecular diversity of HTLV-1 in West Africa.HTLV-1 infected individuals were identified in community surveys between 1990-2007. The complete Long Terminal Repeat (LTR and p24 coding region of HTLV-1 was sequenced from infected subjects. Socio-demographic data were obtained from community census and from interviews performed by fieldworkers. Phylogenetic analyses were performed to characterize the relationship between the Caio HTLV-1 and HTLV-1 from other parts of the world.LTR and p24 sequences were obtained from 72 individuals (36 LTR, 24 p24 only and 12 both. Consistent with the low evolutionary change of HTLV-1, many of the sequences from unrelated individuals showed 100% nucleotide identity. Most (45 of 46 of the LTR sequences clustered with the Cosmopolitan HTLV-1 subtype 1a, subgroup D (1aD. LTR and p24 sequences from two subjects were divergent and formed a significant cluster with HTLV-1 subtype 1g, and with the most divergent African Simian T-cell Lymphotropic Virus, Tan90.The Cosmopolitan HTLV-1 1aD predominates in this rural West African community. However, HTLV-1 subtype 1g is also present. This subtype has not been described before in West Africa and may be more widespread than previously thought. These data are in line with the hypothesis that multiple monkey-to-man zoonotic events are contributing to HTLV-1 diversity.

  20. Imaging of human T-lymphotropic virus type I-associated chronic progressive myeloneuropathies

    International Nuclear Information System (INIS)

    We studied magnetic resonance imaging (MRI) of the head and cervical spine and CT of the head in 46 patients (14 men, 32 women) with chronic progressive myeloneuropathy. The findings were correlated with human T-lymphotropic virus type I (HTLV-I) serology, race, country of origin, and age. We found a female predominance of 2:1. Most patients were aged between 30 and 50 years, and most were Caribbean immigrants and black. There were 9 men and 17 women with blood antibody titers to HTLV-I and 7 mem and 15 women with cerebrospinal fluid (CSF) titers. All patients with virus or antibodies in blood or CSF were Caribbean immigrants or black. T2-weighted cranial MRI showed scattered areas of high signal intensity in the cerebral white matter, usually in the periventricular and subcortical areas, but not in the posterior cranial fossa. Cranial CT revealed periventricular low density areas, ventricular enlargement, and atrophy MRI of the cervical spine showed atrophy of the cord. Myelography was normal in all 15 patients examined. No imaging differences were observed between the HTLV-I-positive and -negative patients. These findings, although consistent with demyelination, are not specific. (orig.)

  1. Leukotrienes Are Upregulated and Associated with Human T-Lymphotropic Virus Type 1 (HTLV-1)-Associated Neuroinflammatory Disease

    Science.gov (United States)

    Trindade, Bruno Caetano; Sorgi, Carlos Artério; Nicolete, Larissa Deadame de Figueiredo; Malta, Tathiane Maistro; Pinto, Mariana Tomazini; Takayanagui, Osvaldo Massaiti; Covas, Dimas Tadeu; Filho, Olindo Assis Martins; Kashima, Simone; Faccioli, Lúcia Helena

    2012-01-01

    Leukotrienes (LTs) are lipid mediators involved in several inflammatory disorders. We investigated the LT pathway in human T-lymphotropic virus type 1 (HTLV-1) infection by evaluating LT levels in HTLV-1-infected patients classified according to the clinical status as asymptomatic carriers (HACs) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients. Bioactive LTB4 and CysLTs were both increased in the plasma and in the supernatant of peripheral blood mononuclear cell cultures of HTLV-1-infected when compared to non-infected. Interestingly, CysLT concentrations were increased in HAM/TSP patients. Also, the concentration of plasma LTB4 and LTC4 positively correlated with the HTLV-1 proviral load in HTLV-1-infected individuals. The gene expression levels of LT receptors were differentially modulated in CD4+ and CD8+ T cells of HTLV-1-infected patients. Analysis of the overall plasma signature of immune mediators demonstrated that LT and chemokine amounts were elevated during HTLV-1 infection. Importantly, in addition to CysLTs, IP-10 was also identified as a biomarker for HAM/TSP activity. These data suggest that LTs are likely to be associated with HTLV-1 infection and HAM/TSP development, suggesting their putative use for clinical monitoring. PMID:23284797

  2. Psychogenic movement disorder in human T-lymphotropic virus type 1 associated myelopathy

    Directory of Open Access Journals (Sweden)

    Marzia Puccioni-Sohler

    2016-01-01

    Full Text Available Human T-lymphotropic virus type 1 (HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP is a chronic inflammatory disorder of the spinal cord. Acute cases of HAM/TSP and those complicated by movement disorders are rarely reported. Otherwise, psychiatric disturbances are very frequent in infected patients. It can evolve to psychogenic disorders. The case of a 46-year-old woman with acute HAM/TSP complicated by depression and psychogenic movement disorders (chorea of the hands and dystonia-like facial symptoms is reported. Brain magnetic resonance imaging revealed non-specific small white matter lesions. The involuntary movements arose suddenly and disappeared when the patient was distracted. Two years of psychotherapy and psychiatric follow-up induced complete remission of the symptoms. The association of psychogenic movement disorders and HAM/TSP, increasing the range of neurological manifestations associated with HTLV-1, is related here. Early diagnosis of psychogenic movement disorders is very important to improve the prognosis and treatment of the two conditions, thereby improving the quality of life of HAM/TSP patients and avoiding irreversible sequelae.

  3. Possible etiologies for tropical spastic paraparesis and human T lymphotropic virus I-associated myelopathy

    Directory of Open Access Journals (Sweden)

    V. Zaninovic'

    2004-01-01

    Full Text Available The epidemiology of tropical spastic paraparesis/human T lymphotropic virus I (HTLV-I-associated myelopathy (TSP/HAM is frequently inconsistent and suggests environmental factors in the etiology of these syndromes. The neuropathology corresponds to a toxometabolic or autoimmune process and possibly not to a viral disease. Some logical hypotheses about the etiology and physiopathology of TSP and HAM are proposed. Glutamate-mediated excitotoxicity, central distal axonopathies, cassava, lathyrism and cycad toxicity may explain most cases of TSP. The damage caused to astrocytes and to the blood-brain barrier by HTLV-I plus xenobiotics may explain most cases of HAM. Analysis of the HTLV-I/xenobiotic ratio clarifies most of the paradoxical epidemiology of TSP and HAM. Modern neurotoxicology, neuroimmunology and molecular biology may explain the neuropathology of TSP and HAM. It is quite possible that there are other xenobiotics implicated in the etiology of some TSP/HAMs. The prevention of these syndromes appears to be possible today.

  4. Retroviral sequences related to human T-lymphotropic virus type II in patients with chronic fatigue immune dysfunction syndrome

    International Nuclear Information System (INIS)

    Chronic fatigue immune dysfunction syndrome (CFIDS) is a recently recognized illness characterized by debilitating fatigue as well as immunological and neurological abnormalities. Once thought to be caused by Epstein-Barr virus, it is now thought to have a different but unknown etiology. The authors evaluted 30 adult and pediatric CFIDS patients from six eastern states for the presence of human T-lymphotropic virus (HTLV) types I and II by Western immunoblotting, polymerase chain reaction, and in situ hybridization of blood samples. The majority of patients were positive for HTLV antibodies by Western blotting and for HTLV-II gag sequences by polymerase chain reaction and in situ hybridization. Twenty nonexposure healthy controls were negative in all assays. These data support an association between an HTLV-II-like virus and CFIDS

  5. Manifestações reumáticas associadas ao vírus linfotrópico humano de células T do tipo I (HTLV-I Rheumatic manifestations associated with the human T-Cell lymphotropic virus type I (HTLV-I

    Directory of Open Access Journals (Sweden)

    Boris A. Cruz

    2005-04-01

    Full Text Available O vírus linfotrópico humano de células T tipo I (HTLV-I é reconhecido como agente etiológico da leucemia de células T do adulto. O HTLV-I é também relacionado a uma mielopatia crônica, que inclui agressão inflamatória (auto imune-mediada em sua patogênese. Outras síndromes auto-imunes, dentre as quais artrite reumatóide e síndrome de Sjögren são descritas em pacientes infectados. Nestes pacientes, estas condições clínicas parecem ser o resultado da interação entre o vírus como fator do ambiente e susceptibilidade do hospedeiro, levando ao funcionamento aberrante de mecanismos imuno-moduladores, proliferação celular e inflamação. O estudo dos aspectos clínicos e imunológicos das manifestações reumáticas associadas ao HTLV-I pode contribuir para o melhor entendimento das doenças auto-imunes.The Human T-Cell Lymphotropic Virus Type I is known as the etiologic agent of Adult T-Cell Leukemia. The HTLV-I is also related to a chronic myelopathy, which includes (auto immune-mediated inflammatory injury in its pathogenesis. Other autoimmune syndromes such as Rheumatoid Arthritis and Sjögren's Syndrome are reported in infected patients. In those patients, these clinical conditions seem to be the result of the interaction between the virus as an environmental agent and host susceptibility, leading to an aberrant functioning of immunomodulatory mechanisms, cellular proliferation and inflammation. The study of clinical and immunological aspects of the HTLV-I-associated rheumatic manifestations may contribute to the better understanding of the auto-immune diseases.

  6. Human T lymphotropic virus type-1 p30II alters cellular gene expression to selectively enhance signaling pathways that activate T lymphocytes

    Directory of Open Access Journals (Sweden)

    Feuer Gerold

    2004-11-01

    Full Text Available Abstract Background Human T-lymphotropic virus type-1 (HTLV-1 is a deltaretrovirus that causes adult T-cell leukemia/lymphoma and is implicated in a variety of lymphocyte-mediated disorders. HTLV-1 contains both regulatory and accessory genes in four pX open reading frames. pX ORF-II encodes two proteins, p13II and p30II, which are incompletely defined in the virus life cycle or HTLV-1 pathogenesis. Proviral clones of the virus with pX ORF-II mutations diminish the ability of the virus to maintain viral loads in vivo. Exogenous expression of p30II differentially modulates CREB and Tax-responsive element-mediated transcription through its interaction with CREB-binding protein/p300 and represses tax/rex RNA nuclear export. Results Herein, we further characterized the role of p30II in regulation of cellular gene expression, using stable p30II expression system employing lentiviral vectors to test cellular gene expression with Affymetrix U133A arrays, representing ~33,000 human genes. Reporter assays in Jurkat T cells and RT-PCR in Jurkat and primary CD4+ T-lymphocytes were used to confirm selected gene expression patterns. Our data reveals alterations of interrelated pathways of cell proliferation, T-cell signaling, apoptosis and cell cycle in p30II expressing Jurkat T cells. In all categories, p30II appeared to be an overall repressor of cellular gene expression, while selectively increasing the expression of certain key regulatory genes. Conclusions We are the first to demonstrate that p30II, while repressing the expression of many genes, selectively activates key gene pathways involved in T-cell signaling/activation. Collectively, our data suggests that this complex retrovirus, associated with lymphoproliferative diseases, relies upon accessory gene products to modify cellular environment to promote clonal expansion of the virus genome and thus maintain proviral loads in vivo.

  7. Ancient, independent evolution and distinct molecular features of the novel human T-lymphotropic virus type 4

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    Wolfe Nathan D

    2009-02-01

    Full Text Available Abstract Background Human T-lymphotropic virus type 4 (HTLV-4 is a new deltaretrovirus recently identified in a primate hunter in Cameroon. Limited sequence analysis previously showed that HTLV-4 may be distinct from HTLV-1, HTLV-2, and HTLV-3, and their simian counterparts, STLV-1, STLV-2, and STLV-3, respectively. Analysis of full-length genomes can provide basic information on the evolutionary history and replication and pathogenic potential of new viruses. Results We report here the first complete HTLV-4 sequence obtained by PCR-based genome walking using uncultured peripheral blood lymphocyte DNA from an HTLV-4-infected person. The HTLV-4(1863LE genome is 8791-bp long and is equidistant from HTLV-1, HTLV-2, and HTLV-3 sharing only 62–71% nucleotide identity. HTLV-4 has a prototypic genomic structure with all enzymatic, regulatory, and structural proteins preserved. Like STLV-2, STLV-3, and HTLV-3, HTLV-4 is missing a third 21-bp transcription element found in the long terminal repeats of HTLV-1 and HTLV-2 but instead contains unique c-Myb and pre B-cell leukemic transcription factor binding sites. Like HTLV-2, the PDZ motif important for cellular signal transduction and transformation in HTLV-1 and HTLV-3 is missing in the C-terminus of the HTLV-4 Tax protein. A basic leucine zipper (b-ZIP region located in the antisense strand of HTLV-1 and believed to play a role in viral replication and oncogenesis, was also found in the complementary strand of HTLV-4. Detailed phylogenetic analysis shows that HTLV-4 is clearly a monophyletic viral group. Dating using a relaxed molecular clock inferred that the most recent common ancestor of HTLV-4 and HTLV-2/STLV-2 occurred 49,800 to 378,000 years ago making this the oldest known PTLV lineage. Interestingly, this period coincides with the emergence of Homo sapiens sapiens during the Middle Pleistocene suggesting that early humans may have been susceptible hosts for the ancestral HTLV-4. Conclusion The

  8. Human T-cell lymphotropic virus type II in Guaraní Indians, Southern Brazil Vírus linfotrópico de células T-humanas do tipo II em Índios Guaraní, Sul do Brasil

    Directory of Open Access Journals (Sweden)

    Marcio Menna-Barreto

    2005-12-01

    Full Text Available Human T-cell lymphotropic virus type II (HTLV-II is found in many New World Indian groups on the American continent. In Brazil, HTLV-II has been found among urban residents and Indians in the Amazon region, in the North. Guaraní Indians in the South of Brazil were studied for HTLV-I/II infection. Among 52 individuals, three (5.76% showed positive anti-HTLV-II antibodies (enzyme-linked immunosorbent assay and Western blot. This preliminary report is the first seroepidemiological study showing HTLV-II infection among Indians in the South of Brazil.O vírus linfotrópico de células T-humanas do tipo II (HTLV-II é identificado em muitos grupos de ameríndios. No Brasil, tem sido encontrado em indivíduos da população urbana, bem como em índios oriundos da região Amazônica. Os Índios Guaraní, do Sul do país, foram investigados para infecção por HTLV-I/II. Três indivíduos, oriundos de uma amostra de 52 índios, demonstraram sororeatividade para HTLV-II (ensaio imunoenzimático e Western blot. Este estudo preliminar foi o primeiro a identificar a presença de infecção por HTLV-II em ameríndios do Sul do Brasil.

  9. Are lipid disorders involved in the predominance of human T-lymphotropic virus-1 infections in women?

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    Luciana Debortoli de Carvalho

    2015-12-01

    Full Text Available Abstract INTRODUCTION : The human T-lymphotropic virus-1 (HTLV-1 is associated with chronic inflammatory diseases such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP, a chronic inflammatory disease. Disturbances in lipid metabolism are involved in inflammatory and demyelinating diseases. METHODS : Plasma levels of triglycerides, total cholesterol, and fractions of HTLV-1-infected individuals of both sexes with different clinical progressions were determined. RESULTS : Elevated levels of triglyceride and very low-density lipoproteins (VLDL were exclusively detected in HTLV-1-infected women from asymptomatic and HAM/TSP groups compared with uninfected individuals (p = 0.02. CONCLUSIONS : Elevated triglyceride and VLDL levels in HTLV-1-infected women may be related to the predominance of HAM/TSP in women.

  10. Molecular Determinants of Human T-lymphotropic Virus Type 1 Transmission and Spread

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    Patrick L. Green

    2011-07-01

    Full Text Available Human T-lymphotrophic virus type-1 (HTLV-1 infects approximately 15 to 20 million people worldwide, with endemic areas in Japan, the Caribbean, and Africa. The virus is spread through contact with bodily fluids containing infected cells, most often from mother to child through breast milk or via blood transfusion. After prolonged latency periods, approximately 3 to 5% of HTLV-1 infected individuals will develop either adult T-cell leukemia/lymphoma (ATL, or other lymphocyte-mediated disorders such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP. The genome of this complex retrovirus contains typical gag, pol, and env genes, but also unique nonstructural proteins encoded from the pX region. These nonstructural genes encode the Tax and Rex regulatory proteins, as well as novel proteins essential for viral spread in vivo such as, p30, p12, p13 and the antisense encoded HBZ. While progress has been made in the understanding of viral determinants of cell transformation and host immune responses, host and viral determinants of HTLV-1 transmission and spread during the early phases of infection are unclear. Improvements in the molecular tools to test these viral determinants in cellular and animal models have provided new insights into the early events of HTLV-1 infection. This review will focus on studies that test HTLV-1 determinants in context to full length infectious clones of the virus providing insights into the mechanisms of transmission and spread of HTLV-1.

  11. Molecular determinants of human T-lymphotropic virus type 1 transmission and spread.

    Science.gov (United States)

    Lairmore, Michael D; Anupam, Rajaneesh; Bowden, Nadine; Haines, Robyn; Haynes, Rashade A H; Ratner, Lee; Green, Patrick L

    2011-07-01

    Human T-lymphotrophic virus type-1 (HTLV-1) infects approximately 15 to 20 million people worldwide, with endemic areas in Japan, the Caribbean, and Africa. The virus is spread through contact with bodily fluids containing infected cells, most often from mother to child through breast milk or via blood transfusion. After prolonged latency periods, approximately 3 to 5% of HTLV-1 infected individuals will develop either adult T-cell leukemia/lymphoma (ATL), or other lymphocyte-mediated disorders such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The genome of this complex retrovirus contains typical gag, pol, and env genes, but also unique nonstructural proteins encoded from the pX region. These nonstructural genes encode the Tax and Rex regulatory proteins, as well as novel proteins essential for viral spread in vivo such as, p30, p12, p13 and the antisense encoded HBZ. While progress has been made in the understanding of viral determinants of cell transformation and host immune responses, host and viral determinants of HTLV-1 transmission and spread during the early phases of infection are unclear. Improvements in the molecular tools to test these viral determinants in cellular and animal models have provided new insights into the early events of HTLV-1 infection. This review will focus on studies that test HTLV-1 determinants in context to full length infectious clones of the virus providing insights into the mechanisms of transmission and spread of HTLV-1. PMID:21994774

  12. Mechanisms of human T-lymphotropic virus type 1 transmission and disease.

    Science.gov (United States)

    Lairmore, Michael D; Haines, Robyn; Anupam, Rajaneesh

    2012-08-01

    Human T-lymphotrophic virus type-1 (HTLV-1) infects approximately 15-20 million people worldwide, with endemic areas in Japan, the Caribbean, and Africa. The virus is spread through contact with bodily fluids containing infected cells most often from mother to child through breast milk or via blood transfusion. After prolonged latency periods, approximately 3-5% of HTLV-1 infected individuals will develop either adult T-cell leukemia/lymphoma, or other lymphocyte-mediated disorders such as HTLV-1-associated myelopathy/tropical spastic paraparesis. The genome of this complex retrovirus contains typical gag, pol, and env genes, but also unique nonstructural proteins encoded from the pX region. These nonstructural genes encode the Tax and Rex regulatory proteins, as well as novel proteins essential for viral spread in vivo such as p30, p12, p13 and the antisense-encoded HTLV-1 basic leucine zipper factor (HBZ). While progress has been made in knowledge of viral determinants of cell transformation and host immune responses, host and viral determinants of HTLV-1 transmission and spread during the early phases of infection are unclear. Improvements in the molecular tools to test these viral determinants in cellular and animal models have provided new insights into the early events of HTLV-1 infection. This review will focus on studies that test HTLV-1 determinants in context to full-length infectious clones of the virus providing insights into the mechanisms of transmission and spread of HTLV-1. PMID:22819021

  13. Histone acetyltransferase (HAT) activity of p300 modulates human T lymphotropic virus type 1 p30II-mediated repression of LTR transcriptional activity

    International Nuclear Information System (INIS)

    Human T-lymphotropic virus type-1 (HTLV-1) is a deltaretrovirus that causes adult T cell leukemia/lymphoma, and is implicated in a variety of lymphocyte-mediated inflammatory disorders. HTLV-1 provirus has regulatory and accessory genes in four pX open reading frames. HTLV-1 pX ORF-II encodes two proteins, p13II and p30II, which are incompletely defined in virus replication or pathogenesis. We have demonstrated that pX ORF-II mutations block virus replication in vivo and that ORF-II encoded p30II, a nuclear-localizing protein that binds with CREB-binding protein (CBP)/p300, represses CREB and Tax responsive element (TRE)-mediated transcription. Herein, we have identified p30II motifs important for p300 binding and in regulating TRE-mediated transcription in the absence and presence of HTLV-1 provirus. Within amino acids 100-179 of p30II, a region important for repression of LTR-mediated transcription, we identified a single lysine residue at amino acid 106 (K3) that significantly modulates the ability of p30II to repress TRE-mediated transcription. Exogenous p300, in a dose-responsive manner, reverses p30II-dependent repression of TRE-mediated transcription, in the absence or presence of the provirus, In contrast to wild type p300, p300 HAT mutants (defective in histone acetyltransferase activity) only partially rescued p30II-mediated LTR repression. Deacetylation by histone deacetylase-1 (HDAC-1) enhanced p30II-mediated LTR repression, while inhibition of deacetylation by trichostatin A decreases p30II-mediated LTR repression. Collectively, our data indicate that HTLV-1 p30II modulates viral gene expression in a cooperative manner with p300-mediated acetylation

  14. Wild-type measles virus infection of primary epithelial cells occurs via the basolateral surface without syncytium formation or release of infectious virus

    NARCIS (Netherlands)

    M. Ludlow (Martin); L.J. Rennick (Linda); S. Sarlang (Severine); G. Skibinski (Grzegorz); S. McQuaid (Stephen); T. Moore (Tara); R.L. de Swart (Rik); W.P. Duprex (Paul)

    2010-01-01

    textabstractThe lymphotropic and myelotropic nature of wild-type measles virus (wt-MV) is well recognized, with dendritic cells and lymphocytes expressing the MV receptor CD150 mediating systemic spread of the virus. Infection of respiratory epithelial cells has long been considered crucial for entr

  15. Human T-Lymphotropic Virus Type I (HTLV-1 Infection among Iranian Blood Donors: First Case-Control Study on the Risk Factors

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Hedayati-Moghaddam

    2015-11-01

    Full Text Available Human T-cell lymphotropic virus type 1 (HTLV-1 infection is an endemic condition in Northeast Iran and, as such, identification of risk factors associated with the infection in this region seems to be a necessity. All the possible risk factors for HTLV-1 seropositivity among first-time blood donors were evaluated in Mashhad, Iran, during the period of 2011–2012. Blood donation volunteers were interviewed for demographic data, medical history, and behavioral characteristics and the frequencies of risk factors were compared between HTLV-1 positive (case and HTLV-1 negative (control donors. The data was analyzed using Chi square and t-tests. Logistic regression analysis was performed to identify independent risk factors for the infection. Assessments were carried out on 246 cases aged 17–60 and 776 controls aged 17–59, who were matched based on their ages, gender, and date and center of donation. Logistic analysis showed low income (OR = 1.53, p = 0.035, low educational level (OR = 1.64, p = 0.049, being born in the cities of either Mashhad (OR = 2.47, p = 0.001 or Neyshabour (OR = 4.30, p < 0001, and a history of blood transfusion (OR = 3.17, p = 0.007 or non-IV drug abuse (OR = 3.77, p < 0.0001 were significant predictors for infection with HTLV-1. Lack of variability or small sample size could be reasons of failure to detect some well-known risk factors for HTLV-1 infection, such as prolonged breastfeeding and sexual promiscuity. Pre-donation screening of possible risk factors for transfusion-transmissible infections should also be considered as an important issue, however, a revision of the screening criteria such as a history of transfusion for more than one year prior to donation is strongly recommended.

  16. Human T-Lymphotropic Virus Type 1 and 2 Seroprevalence among first-time blood donors in Chile, 2011-2013.

    Science.gov (United States)

    San Martín, Héctor; Balanda, Monserrat; Vergara, Nicolás; Valenzuela, María Antonieta; Cartier, Luis; Ayala, Salvador; Ramírez, Eugenio

    2016-06-01

    Infection with human T-lymphotropic virus type 1/2 (HTLV-1/2) is a major health problem. HTLV-1/2 infection is endemic in Chile but representative donor prevalence data are lacking. Data on all blood donors in a large network of Chilean blood centers were examined during 2011-2013. Screening of HTLV-1/2 antibodies were measured by enzyme immunoassay (EIA) at all blood banks. Blood samples with anticoagulants from initially reactive blood donors were analyzed by serological confirmation tests (immunofluorescence or recombinant immunoblot) at the HTLV National Reference Laboratory of the Public Health Institute of Chile. Additionally, detection of HTLV-1 and HTLV-2 provirus in peripheral blood mononuclear cells (PBMCs) was performed in all blood donors as confirmatory test. Prevalence rates were calculated. Among 694,016 donors, 706 were seropositive for HTLV-1 (prevalence, 1.02 cases per 1,000; 95% confidence interval [CI], 0.94-1.09), and 97 were seropositive for HTLV-2 (prevalence, 0.14 cases per 1,000; 95%CI, 0.11-0.17). Prevalence of HTLV-1 differed considerably by region, from 0.51 to 1.69 per 1,000. Prevalence of HTLV-2 was similar across the country (0.12-0.16). HTLV-1 prevalence was associated with female sex, older age, and residence in the north of Chile. HTVL-2 prevalence was associated with older age. The HTLV-1 prevalence among Chilean blood donors was relatively high and could be reduced by improving donor recruitment and selection in high prevalence areas. Blood center data may contribute to surveillance for HTLV-1 and HTLV-2 infections. PMID:26538335

  17. Novel Gene Therapy Viral Vector Using Non-Oncogenic Lymphotropic Herpesvirus

    OpenAIRE

    Akihiro Shimizu; Nobuyuki Kobayashi; Kazuya Shimada; Kuniaki Oura; Tadao Tanaka; Aikou Okamoto; Kazuhiro Kondo

    2013-01-01

    Despite the use of retroviral vectors, efficiently introducing target genes into immunocytes such as T cells is difficult. In addition, retroviral vectors carry risks associated with the oncogenicity of the native virus and the potential for introducing malignancy in recipients due to genetic carryover from immortalized cells used during vector production. To address these issues, we have established a new virus vector that is based on human herpesvirus 6 (HHV-6), a non-oncogenic lymphotropic...

  18. Human T-Lymphotropic virus (HTLV type I in vivo integration in oral keratinocytes

    Directory of Open Access Journals (Sweden)

    Martha C Domínguez

    2011-03-01

    Full Text Available Although the infection of HTLV-1 to cell components of the mouth have been previously reported, there was not until this report, a detailed study to show the characteristics of such infection. From 14 Tropical Spastic Paraparesis/ HTLV-1-Associated Myelopathy (HAM/TSP patients and 11 asymptomatic carrier individuals (AC coming from HTLV-1 endemic areas of southwest Pacific of Colombia, infected oral mucosa cells were primary cultured during five days. These cell cultures were immunophenotyped by dual color fluorescence cell assortment using different lymphocyte CD markers and also were immunohistochemically processed using a polyclonal anti-keratin antibody. Five days old primary cultures were characterized as oral keratinocytes, whose phenotype was CD3- /CD4-/CD8-/CD19-/CD14-/CD45-/A575-keratin+. From DNA extracted of primary cultures LTR, pol, env and tax HTLV-1 proviral DNA regions were differentially amplified by PCR showing proviral integration. Using poly A+ RNA obtained of these primary cultures, we amplify by RT-PCR cDNA of tax and pol in 57.14% (8/14 HAM/TSP patients and 27.28% (3/11 AC. Tax and pol poly A+ RNA were expressed only in those sIgA positive subjects. Our results showed that proviral integration and viral gene expression in oral keratinocytes are associated with a HTLV-1 specific local mucosal immune response only in those HTLV-1 infected individuals with detectable levels of sIgA in their oral fluids. Altogether the results gave strong evidence that oral mucosa infection would be parte of the systemic spreading of HTLV-1 infection.

  19. Soroprevalência e perfil imunofenotípico de células linfóides T em indivíduos soropositivos para o vírus linfotrópico de células T humanas Seroprevalence and immunophenotypic profile of T lymphocyte cells in human T lymphotropic virus seropositive individuals

    Directory of Open Access Journals (Sweden)

    Geane F. de Sóuza

    2003-03-01

    Full Text Available O vírus linfotrópico de células T humana (HTLV é transmitido por transfusões, uso compartilhado de agulhas contaminadas, aleitamento e contato sexual. A prevalência varia de acordo com a região geográfica, grupo racial e população estudada. Cerca de 1% a 4% dos indivíduos infectados desenvolvem algum tipo de doença em decorrência da infecção. É reconhecida a associação entre o HTLV-I e leucemia de células T do adulto e paraparesia espástica tropical (PET. Embora a maioria dos portadores permaneça assintomática, existem evidências de comprometimento funcional da resposta imune celular. Os objetivos desse trabalho foram avaliar a prevalência de soropositividade para HTLV-I/II na população de doadores de sangue do HEMOCE e analisar o perfil imunofenotípico de células linfóides circulantes em 26 doadores soronegativos, 11 soropositivos para HTLV-I sintomáticos e 24 assintomáticos, comparando-os entre si. A prevalência da soropositividade para HTLV-I/II foi de 0,66%. No grupo de indivíduos contaminados pelo HTLV-I houve predomínio do sexo feminino e a maior média de idade. O grupo soropositivo apresentou menor valor de hemoglobina e o grupo sintomático evidenciou contagem de neutrófilos significativamente mais elevada. A contagem média de linfócitos não diferiu entre os grupos. A análise imunofenotípica mostrou que os valores médios de células CD3+, CD4+, CD8+ e relação CD4/CD8 não diferiram significativamente entre os grupos. Uma elevação de células CD8+ no grupo soropositivo foi observada embora não alcançasse significância estatística. A ativação de linfócitos CD8+ está envolvida na patogênese das doenças associadas ao HTLV-I. A definição do valor preditivo desse achado requer confirmação posterior.Human T lymphotropic virus (HTLV can be transmitted by transfusions of cellular blood products, shared use of contaminated syringes, breast feeding and sexual intercourse. The prevalence of

  20. Development and Validation of a Multiplex Real-Time PCR Assay for Simultaneous Genotyping and Human T-Lymphotropic Virus Type 1, 2, and 3 Proviral Load Determination ▿

    OpenAIRE

    Moens, Britta; López1, Giovanni; Adaui, Vanessa; González, Elsa; Kerremans, Lien; Clark, Daniel; Verdonck, Kristien; Gotuzzo, Eduardo; Vanham, Guido; Cassar, Olivier; Gessain, Antoine; Vandamme, Anne-Mieke; Van Dooren, Sonia

    2009-01-01

    The human T-lymphotropic virus (HTLV) proviral load remains the best surrogate marker for disease progression. Real-time PCR techniques have been developed for detection and quantification of cosmopolitan HTLV type 1a (HTLV-1a) and HTLV-2. Since a growing level of diversity in subtypes and genotypes is observed, we developed a multiplex quantitative PCR for simultaneous detection, genotyping, and quantification of proviral loads of HTLV-1, 2, and 3. Our assay uses tax type-specific primers an...

  1. Prevalência, fatores de risco e caracterização genética dos vírus linfotrópico de células T humana tipo 1 e 2 em pacientes infectados pelo vírus da imunodeficiência humana tipo 1 nas Cidades de Ribeirão Preto e São Paulo Prevalence, risk factors and genetic characterization of human T-cell lymphotropic virus types 1 and 2 in patients infected with human immunodeficiency virus type 1 in the cities of Ribeirão Preto and São Paulo

    Directory of Open Access Journals (Sweden)

    Walter Kleine Neto

    2009-06-01

    Full Text Available O objetivo deste estudo foi definir a prevalência dos vírus linfotrópico de células T humana tipo 1 e 2 em pacientes positivos para o vírus da imunodeficiência humana tipo 1 no Estado de São Paulo, Brasil. Avaliamos 319 indivíduos atendidos em clínicas de Ribeirão Preto e Capital. Os pacientes foram entrevistados e testados sorologicamente. Foram seqüenciadas as regiões tax e long terminal repeat para diferenciação e determinação do subtipo. A soroprevalência geral foi de 7,5% (24/319 e esteve associada somente com uso de drogas injetáveis e ao vírus da hepatite tipo C (pThe aim of this study was to define the prevalence of human T cell lymphotropic virus types 1 and 2 in patients who were positive for human immunodeficiency virus type 1 in the State of São Paulo, Brazil. We evaluated 319 individuals infected with HIV type 1 who were attended at specialized clinics in two cities (Ribeirão Preto and São Paulo. The patients were interviewed and tested for antibodies against HTLV types 1 and 2 (Orthoâ HTLV-1/HTLV-2 Ab-Capture enzyme immunoassay. Direct DNA sequencing of polymerase chain reaction products from the tax region of HTLV type 2 and the long terminal repeat region of HTLV types 1 and 2 were performed to differentiate and determine the subtypes. The overall prevalence of anti-HTLV type 1 and 2 antibodies was 7.5% (24/319; 95% CI: 5.2-11.5. HTLV type 1 and 2 infection was associated with a history of injected drug use and with antibodies for hepatitis C virus (p 0.05. HTLV DNA was detected in 13 out of 24 samples, of which 12 were characterized as HTLV subtype 2c and one as HTLV subtype 1a. Among the 12 HTLV type 2 samples, seven were from injected drug users, thus indicating that this route is an important risk factor for HTLV type 2 transmission among our population infected with HIV type 1.

  2. Quantification of Human T-lymphotropic virus type I (HTLV-I) provirus load in a rural West African population: no enhancement of human immunodeficiency virus type 2 pathogenesis, but HTLV-I provirus load relates to mortality

    DEFF Research Database (Denmark)

    Ariyoshi, K; Berry, N; Cham, F;

    2003-01-01

    Human T-lymphotropic virus type I (HTLV-I) provirus load was examined in a cohort of a population in Guinea-Bissau among whom human immunodeficiency virus (HIV) type 2 is endemic. Geometric mean of HIV-2 RNA load among HTLV-I-coinfected subjects was significantly lower than that in subjects...... infected with HIV-2 alone (212 vs. 724 copies/mL; P=.02). Adjusted for age, sex, and HIV status, the risk of death increased with HTLV-I provirus load; mortality hazard ratio was 1.59 for each log10 increase in HTLV-I provirus copies (P=.038). There is no enhancing effect of HTLV-I coinfection on HIV-2...

  3. Decline in prevalence and asymmetric distribution of human T cell lymphotropic virus 1 and 2 in blood donors, State of Minas Gerais, Brazil, 1993 to 2007 Declínio na prevalência e distribuição assimétrica do vírus linfotrópico de células T humanas em doadores de sangue, Estado de Minas Gerais, Brasil, 1993 a 2007

    Directory of Open Access Journals (Sweden)

    Maria Regina Dias-Bastos

    2010-12-01

    Full Text Available INTRODUCTION: Human T cell lymphotropic virus types 1 and 2 (HTLV-1/2 are endemic in Brazil and are screened for in transfusion services since 1993. This study evaluated the evolution of the prevalence of HTLV-1 and 2 in blood donors of the Hemominas Foundation from 1993 to 2007, and its geographical distribution in State of Minas Gerais, Brazil. METHODS: The Hemominas Foundation is a centralized blood center in Minas Gerais, Brazil. The sources of data were the Hemominas Foundation Technical Bulletin and files from the centralized serological laboratory. Donors were tested in the period using enzyme linked immuno sorbent assays (ELISA, followed by Western blot, when repeatedly reactive. The data were analyzed by EPIINFO 6.2 and TABWIN 3.5 softwares. RESULTS: The average seroprevalence in the period 1993-2007 was 0.1%. A steady decline occurred from 0.4% in 1993 to below 0.1% in 2002 and later, with a transient peak of 0.5% in 1994. HTLV reactivity distribution was asymmetrical in the state, with regions of higher prevalence, interspersed with low prevalence areas. Comparison of positive and negative donors verified that increasing age was proportional to virus positivity. Odds ratio for age ranged from 1.43 (30 to 39 years-old to 3.09 (50 to 65 years-old. Women had a greater chance of being positive (OR-1.64, as previously described. CONCLUSIONS: Possible explanations for HTLV-1/2 prevalence decline are the exclusion of positive donors from the donor pool, an increase in repeat donors and ELISA test improvement, with reduction in the number of false positive results.INTRODUÇÃO: Os vírus linfotrópicos de células T humanas 1 e 2 (HTLV-1/2 são endêmicos no Brasil e são testados nos serviços de transfusão desde 1993. Este estudo avaliou a evolução da prevalência do HTLV-1 e 2 em doadores de sangue da Hemominas, de 1993 a 2007, bem como sua distribuição geográfica no Estado de Minas Gerais, Brasil. MÉTODOS: A Hemominas é um servi

  4. Epigenetic mechanisms in virus-induced tumorigenesis

    OpenAIRE

    Poreba, Elzbieta; Broniarczyk, Justyna Karolina; Gozdzicka-Jozefiak, Anna

    2011-01-01

    About 15–20% of human cancers worldwide have viral etiology. Emerging data clearly indicate that several human DNA and RNA viruses, such as human papillomavirus, Epstein–Barr virus, Kaposi’s sarcoma-associated herpesvirus, hepatitis B virus, hepatitis C virus, and human T-cell lymphotropic virus, contribute to cancer development. Human tumor-associated viruses have evolved multiple molecular mechanisms to disrupt specific cellular pathways to facilitate aberrant replication. Although oncogeni...

  5. Immunological methods for the detection of porcine lymphotropic herpesviruses (PLHV).

    Science.gov (United States)

    Plotzki, Elena; Keller, Martina; Ehlers, Bernhard; Denner, Joachim

    2016-07-01

    Porcine lymphotropic herpesviruses (PLHV-1, -2, and -3) are widespread in pigs and closely related to the human pathogenic gammaherpesviruses Epstein-Barr virus (human herpesvirus 4, HHV-4) and Kaposi sarcoma herpesvirus (HHV-8). In minipigs, PLHV-1 causes a porcine post-transplantation lymphoproliferative disorder (PTLD) after experimental transplantations. Porcine PTLD comes with clinical symptoms similar to those of human PTLD, a serious complication of solid organ and allogeneic bone marrow transplantation linked to HHV-4. Since PLHVs may be transmitted from donor pigs to the human recipient of xenotransplants (pig cells, tissues or organs), sensitive and specific methods should be developed to detect and eliminate PLHVs. Here we describe an ELISA and a Western blot assay using recombinant glycoprotein B of PLHV-1. Using both assays, the presence of specific antibodies in different pig breeds as well as in German slaughterhouse workers was analysed. Antibodies were detected in some animals, but not in human subjects. PMID:27036503

  6. Isolation of a new herpes virus from human CD4 sup + T cells

    Energy Technology Data Exchange (ETDEWEB)

    Frenkel, N.; Schirmer, E.C.; Wyatt, L.S.; Katsafanas, G.; Roffman, E.; Danovich, R.M. (National Institutes of Health, Rockville, MD (USA)); June, C.H. (Naval Medical Research Institute, Bethesda, MD (USA))

    1990-01-01

    A new human herpes virus has been isolated from CD4{sup +} T cells purified from peripheral blood mononuclear cells of a healthy individual (RK), following incubation of the cells under conditions promoting T-cell activation. The virus could not be recovered from nonactivated cells. Cultures of lymphocytes infected with the RK virus exhibited a cytopathic effect, and electron microscopic analyses revealed a characteristic herpes virus structure. RK virus DNA did not hybridize with large probes derived from herpes simplex virus, Epstein-Barr virus, varicella-zoster virus, and human cytomegalovirus. The genetic relatedness of the RK virus to the recently identified T-lymphotropic human herpes virus 6 (HHV-6) was investigated by restriction enzyme analyses using 21 different enzymes and by blot hydridization analyses using 11 probes derived from two strains of HHV-6 (Z29 and U1102). Whereas the two HHV-6 strains exhibited only limited restriction enzyme polymorphism, cleavage of the RK virus DNA yielded distinct patterns. Of the 11 HHV-6 DNA probes tested, only 6 cross-hybridized with DNA fragments derived from the RK virus. Taken together, the maximal homology amounted to 31 kilobases of the 75 kilobases tested. The authors conclude that the RK virus is distinct from previously characterized human herpesviruses. The authors propose to designate it as the prototype of a new herpes virus, the seventh human herpes virus identified to date.

  7. PCR detection and DNA sequence analysis of the regulatory region of lymphotropic papovavirus in peripheral blood mononuclear cells of an immunocompromised rhesus macaque

    Science.gov (United States)

    Lednicky, John A.; Halvorson, Steven J.; Butel, Janet S.

    2002-01-01

    A lymphotropic papovavirus (LPV) archetypal regulatory region was amplified from DNA from the blood of an immunocompromised rhesus monkey. We believe this is the first nonserological evidence of LPV infection in rhesus monkeys.

  8. Transformation of human cells by oncogenic viruses supports permissiveness for parvovirus H-1 propagation.

    Science.gov (United States)

    Faisst, S; Schlehofer, J R; zur Hausen, H

    1989-01-01

    Parvovirus H-1 has been shown to suppress spontaneous and chemically or virally induced tumorigenesis in hamsters. In human cell culture systems propagation of H-1 is restricted to transformed cells, which are killed by H-1 infection, in contrast to normal diploid cells, which are nonpermissive for H-1. By analyzing the permissiveness of a variety of human cells for H-1, it was determined that the majority of tested transformed or immortalized cells which were permissive for H-1 contained the DNA of oncogenic viruses (human papillomavirus, simian virus 40, adenovirus, hepatitis B virus, Epstein-Barr virus, and human T-cell lymphotropic virus type I). Of six transformed cell lines negative for persisting tumor virus DNA, only two were permissive for H-1, while two were semipermissive and two were nonpermissive. Thus, persistence and expression of tumor virus functions appears to promote full permissiveness for H-1 in human cells. However, neither expression of genes of specific viral genomes nor the transformed state of apparently virus-free cells alone was sufficient to render human cells permissive for H-1. Therefore, the effect of tumor virus functions on H-1 in transformed cells seems to be indirect, probably mediated by cellular factors which are induced or switched off during the transformation process. It appears that similar factors are induced or switched off by 5-azacytidine or calcium phosphate, both known inducers of cellular gene expression. Images PMID:2495371

  9. Evaluation of the use of real-time PCR for human T cell lymphotropic virus 1 and 2 as a confirmatory test in screening for blood donors Análise do uso da PCR em tempo real para HTLV-1 e 2 como teste confirmatório na triagem de doadores de sangue

    Directory of Open Access Journals (Sweden)

    Rafaela Gomes Andrade

    2010-04-01

    Full Text Available INTRODUCTION: HTLV-1/2 screening among blood donors commonly utilizes an enzyme-linked immunosorbent assay (EIA, followed by a confirmatory method such as Western blot (WB if the EIA is positive. However, this algorithm yields a high rate of inconclusive results, and is expensive. METHODS: Two qualitative real-time PCR assays were developed to detect HTLV-1 and 2, and a total of 318 samples were tested (152 blood donors, 108 asymptomatic carriers, 26 HAM/TSP patients and 30 seronegative individuals. RESULTS: The sensitivity and specificity of PCR in comparison with WB results were 99.4% and 98.5%, respectively. PCR tests were more efficient for identifying the virus type, detecting HTLV-2 infection and defining inconclusive cases. CONCLUSIONS: Because real-time PCR is sensitive and practical and costs much less than WB, this technique can be used as a confirmatory test for HTLV in blood banks, as a replacement for WB.INTRODUÇÃO: A triagem para HTLV-1/2 em doadores de sangue geralmente utiliza imunoensaio enzimático, seguido de um método confirmatório como Western blot quando o EIA é positivo, mas este algoritmo mostra alta taxa de resultados inconclusivos, e elevado custo. MÉTODOS: Dois ensaios qualitativos de PCR em tempo real foram desenvolvidos para detectar HTLV-1 e 2 e um total de 318 amostras foram testadas por PCR (152 de doadores de sangue, 108 de portadores assintomáticos, 26 de pacientes HAM/TSP e 30 de indivíduos soronegativos. RESULTADOS: A sensibilidade e especificidade das PCR em relação aos resultados de WB foram de 99,4% e 98,5%, respectivamente. As PCR foram mais eficientes em identificar o tipo viral, a infecção pelo HTLV-2 e úteis para definir casos inconclusivos. CONCLUSÕES: Por serem sensíveis, práticas e de custo muito inferior ao do WB, as técnicas de PCR em tempo real podem ser usadas como teste confirmatório do HTLV em bancos de sangue, em substituição ao WB.

  10. Antibody to human T-lymphotropic virus in a patient with Guillain-Barré syndrome (case report) Anticorpo para o vírus linfotrópico humano T em um paciente com a síndrome de Guillain-Barré

    OpenAIRE

    C. M. Nakauchi; A.C. Linhares; Gomes, M.L.C.; Maruyama, K.; L. I. Kanzaki; V.N. Azevedo

    1991-01-01

    Serum sample obtained from a male, 12 year old patient suffering from Guillain-Barré syndrome (GBS) was positive for human T-lymphotropic virus (HTLV-I) antibody by the enzyme-linked immunosorbent assay (ELISA) and the Western Blot analysis (WB). Attempts to isolate enteroviruses (including poliovirus) from faecal material in both tissue culture and suckling mice were unsuccessful; in addition, acute and convalescent paired serum samples did not show any evidence of recent poliovirus infectio...

  11. Canine Distemper Virus Infection Leads to an Inhibitory Phenotype of Monocyte-Derived Dendritic Cells In Vitro with Reduced Expression of Co-Stimulatory Molecules and Increased Interleukin-10 Transcription

    OpenAIRE

    Visar Qeska; Yvonne Barthel; Vanessa Herder; Stein, Veronika M.; Andrea Tipold; Carola Urhausen; Anne-Rose Günzel-Apel; Karl Rohn; Wolfgang Baumgärtner; Andreas Beineke

    2014-01-01

    Canine distemper virus (CDV) exhibits a profound lymphotropism that causes immunosuppression and increased susceptibility of affected dogs to opportunistic infections. Similar to human measles virus, CDV is supposed to inhibit terminal differentiation of dendritic cells (DCs), responsible for disturbed repopulation of lymphoid tissues and diminished antigen presenting function in dogs. In order to testify the hypothesis that CDV-infection leads to an impairment of professional antigen present...

  12. Detailed phylogenetic analysis of primate T-lymphotropic virus type 1 (PTLV-1) sequences from orangutans (Pongo pygmaeus) reveals new insights into the evolutionary history of PTLV-1 in Asia.

    Science.gov (United States)

    Reid, Michael J C; Switzer, William M; Schillaci, Michael A; Ragonnet-Cronin, Manon; Joanisse, Isabelle; Caminiti, Kyna; Lowenberger, Carl A; Galdikas, Birute Mary F; Sandstrom, Paul A; Brooks, James I

    2016-09-01

    While human T-lymphotropic virus type 1 (HTLV-1) originates from ancient cross-species transmission of simian T-lymphotropic virus type 1 (STLV-1) from infected nonhuman primates, much debate exists on whether the first HTLV-1 occurred in Africa, or in Asia during early human evolution and migration. This topic is complicated by a lack of representative Asian STLV-1 to infer PTLV-1 evolutionary histories. In this study we obtained new STLV-1 LTR and tax sequences from a wild-born Bornean orangutan (Pongo pygmaeus) and performed detailed phylogenetic analyses using both maximum likelihood and Bayesian inference of available Asian PTLV-1 and African STLV-1 sequences. Phylogenies, divergence dates and nucleotide substitution rates were co-inferred and compared using six different molecular clock calibrations in a Bayesian framework, including both archaeological and/or nucleotide substitution rate calibrations. We then combined our molecular results with paleobiogeographical and ecological data to infer the most likely evolutionary history of PTLV-1. Based on the preferred models our analyses robustly inferred an Asian source for PTLV-1 with cross-species transmission of STLV-1 likely from a macaque (Macaca sp.) to an orangutan about 37.9-48.9kya, and to humans between 20.3-25.5kya. An orangutan diversification of STLV-1 commenced approximately 6.4-7.3kya. Our analyses also inferred that HTLV-1 was first introduced into Australia ~3.1-3.7kya, corresponding to both genetic and archaeological changes occurring in Australia at that time. Finally, HTLV-1 appears in Melanesia at ~2.3-2.7kya corresponding to the migration of the Lapita peoples into the region. Our results also provide an important future reference for calibrating information essential for PTLV evolutionary timescale inference. Longer sequence data, or full genomes from a greater representation of Asian primates, including gibbons, leaf monkeys, and Sumatran orangutans are needed to fully elucidate these

  13. Human T-lymphotropic virus type 1 (HTLV-1 prevalence and quantitative detection of DNA proviral load in individuals with indeterminate/positive serological results

    Directory of Open Access Journals (Sweden)

    Bon Isabella

    2006-03-01

    Full Text Available Abstract Background HTLV-1 infection is currently restricted to endemic areas. To define the prevalence of HTLV-1 infection in patients living in Italy, we first carried out a retrospective serological analysis in a group of people originating from African countries referred to our hospital from January 2003 to February 2005. We subsequently applied a real time PCR on peripheral blood mononuclear cells from subjects with positive or indeterminate serological results. Methods All the sera were first analysed by serological methods (ELISA and/or Western Blotting and then the peripheral blood mononuclear cells from subjects with positive or inconclusive serological results were analyzed for the presence of proviral DNA by a sensitive SYBR Green real time PCR. In addition, twenty HTLV-I ELISA negative samples were assayed by real time PCR approach as negative controls. Results Serological results disclosed serum reactivity by ELISA (absorbance values equal or greater than the cut-off value in 9 out of 3408 individuals attending the Sexually Transmitted Diseases Clinic and/or Oncology Department, and 2 out 534 blood donors enrolled as a control population. Irrespective of positive or inconclusive serological results, all these subjects were analyzed for the presence of proviral DNA in peripheral blood mononuclear cells by SYBR real time PCR. A clear-cut positive result for the presence of HTLV-1 DNA was obtained in two subjects from endemic areas. Conclusion SYBR real time PCR cut short inconclusive serological results. This rapid and inexpensive assay showed an excellent linear dynamic range, specificity and reproducibility readily revealing and quantifying the presence of virus in PBMCs. Our results highlight the need to monitor the presence of HTLV-1 in countries which have seen a large influx of immigrants in recent years. Epidemiological surveillance and correct diagnosis are recommended to verify the prevalence and incidence of a new

  14. Antibody to human T-lymphotropic virus in a patient with Guillain-Barré syndrome (case report Anticorpo para o vírus linfotrópico humano T em um paciente com a síndrome de Guillain-Barré

    Directory of Open Access Journals (Sweden)

    C.M. Nakauchi

    1991-08-01

    Full Text Available Serum sample obtained from a male, 12 year old patient suffering from Guillain-Barré syndrome (GBS was positive for human T-lymphotropic virus (HTLV-I antibody by the enzyme-linked immunosorbent assay (ELISA and the Western Blot analysis (WB. Attempts to isolate enteroviruses (including poliovirus from faecal material in both tissue culture and suckling mice were unsuccessful; in addition, acute and convalescent paired serum samples did not show any evidence of recent poliovirus infection when tested against the three serotypes. Specific tests for detection of Epstein-Barr virus infection were not performed; however, the Paul-Bunnel test yielded negative results. ELISA for detection of anti-cytomegalovirus IgM was also negative. The concomitant occurrence of either adult T cell leukemia (ATL or lymphoma was not recorded in this case.Amostra de soro obtida de paciente com a síndrome de Guillain-Barré revelou-se positiva quanto à presença de anticorpos para o vírus linfotrópico humano T (HTLV-I pelo método imuno-enzimático (ELISA e a análise por "Western-Blot". Resultaram negativos os testes visando à detecção de enterovírus (incluindo poliovírus a partir de material fecal, tanto em cultura de tecidos como em camundongos recém-nascidos; exames com amostras de soro aguda e convalescente não exibiram qualquer evidência de infecção recente pelos três tipos de poliovírus. O teste de Paul-Bunnel, assim como o "ELISA" para a detecção de IgM anti-citomegalovírus resultaram negativos. Não foi registrada, no presente caso, quer a leucemia adulta de células T, quer linfomas.

  15. Human herpesvirus-8/Kaposi's sarcoma-associated herpesvirus is a new transmissible virus that infects B cells

    OpenAIRE

    1996-01-01

    Herpesviral DNA fragments isolated from AIDS-associated Kaposi's sarcoma (KS) tissue (KSHV-DNA) share homology with two lymphotropic oncogenic gamma-herpesviruses, Epstein-Barr virus and Herpesvirus saimiri, and are present in the lesions of more than 95% of HIV and non- HIV-associated forms of KS, AIDS-related body cavity-based lymphomas, and AIDS-related multicentric Castleman's disease. Here we show that BC- 1, a KSHV-DNA-positive, body cavity-based lymphoma cell line, produces infective h...

  16. Hepatitis C virus - associated B cell non-Hodgkin's lymphoma

    Science.gov (United States)

    Mihăilă, Romeo-Gabriel

    2016-01-01

    The hepatitis C virus (HCV) infected patients are prone to develop bone marrow or various tissue infiltrates with monoclonal B cells, monoclonal B lymphocytosis or different types of B cell non-Hodgkin’s lymphoma (BCNHL), of which the most common are splenic marginal zone BCNHL, diffuse large BCNHL and follicular lymphoma. The association between chronic HCV infection and non Hodgkin’s lymphoma has been observed especially in areas with high prevalence of this viral infection. Outside the limitations of some studies that have been conducted, there are also geographic, environmental, and genetic factors that contribute to the epidemiological differences. Various microenvironmental signals, such as cytokines, viral antigenic external stimulation of lymphocyte receptors by HCV antigens, and intercellular interactions contribute to B cell proliferation. HCV lymphotropism and chronic antigenic stimulation are involved in B-lymphocyte expansion, as mixted cryoglobulinemia or monoclonal gammopathy of undetermined significance, which can progress to BCNHL. HCV replication in B lymphocytes has oncogenic effect mediated by intracellular HCV proteins. It is also involved in an important induction of reactive oxygen species that can lead to permanent B lymphocyte damage, as DNA mutations, after binding to surface B-cell receptors. Post-transplant lymphoproliferative disorder could appear and it has a multiclonal potentiality that may develop into different types of lymphomas. The hematopoietic stem cell transplant made for lymphoma in HCV-infected patients can increase the risk of earlier progression to liver fibrosis and cirrhosis. HCV infected patients with indolent BCNHL who receive antiviral therapy can be potentially cured. Viral clearance was related to lymphoma response, fact that highlights the probable involvement of HCV in lymphomagenesis. Direct acting antiviral drugs could be a solution for the patients who did not tolerate or respond to interferon, as they

  17. Relative frequency of Human T-cell Lymphotropic Virus I/II in HIV/AIDS patients

    Directory of Open Access Journals (Sweden)

    Mohsen Meidani

    2014-01-01

    Conclusion: In our survey, relative frequency of HTLV-I/II was 1.8% in HIV+ patients. This study reveals that relative frequency of HTLV-I/II in HIV positive patients is considerable but determining the need for screening of HTLV-I/II requires further investigation.

  18. Cell-mediated immunity and lymphocyte populations in experimental Argentine hemorrhagic fever (Junín Virus).

    OpenAIRE

    Carballal, G; Oubiña, J. R.; Rondinone, S N; Elsner, B; Frigerio, M J

    1981-01-01

    Guinea pigs infected with the XJ prototype strain of Junín virus reproduce the main features of Argentine hemorrhagic fever, showing hemorrhages, leukothrombocytopenia, and focal lymphoid tissue necrosis. Viral lymphotropism is shown by the presence of viral antigens, severe cytopathic effect, and high virus titers in lymphoid organs. A pronounced depression of humoral immune response to sheep erythrocytes as well as to the virus is described. This study was carried out to determine whether c...

  19. Cell killing by avian leukosis viruses.

    OpenAIRE

    Weller, S K; Temin, H M

    1981-01-01

    Infection of chicken cells with a cytopathic avian leukosis virus resulted in the detachment of killed cells from the culture dish. The detached, dead cells contained more unintegrated viral DNA than the attached cells. These results confirm the hypothesis that cell killing after infection with a cytopathic avian leukosis virus is associated with accumulation of large amounts of unintegrated viral DNA. No accumulation of large amounts of integrated viral DNA was found in cells infected with c...

  20. Detection of Active Epstein-Barr Virus Infection in Duodenal Mucosa of Patients With Refractory Celiac Disease.

    Science.gov (United States)

    Perfetti, Vittorio; Baldanti, Fausto; Lenti, Marco Vincenzo; Vanoli, Alessandro; Biagi, Federico; Gatti, Marta; Riboni, Roberta; Dallera, Elena; Paulli, Marco; Pedrazzoli, Paolo; Corazza, Gino Roberto

    2016-08-01

    Refractory celiac disease is characterized by mucosal damage in patients with celiac disease despite a gluten-free diet. Little is known about the mechanisms that cause persistent intestinal inflammation in these patients. We performed a case-control study of 17 consecutive patients diagnosed with refractory celiac disease from 2001 through 2014 (median age, 51 y; 10 women) and 24 patients with uncomplicated celiac disease (controls) to determine whether refractory disease is associated with infection by lymphotropic oncogenic viruses. We performed real-time PCR analyses of duodenal biopsy samples from all patients to detect Epstein-Barr virus (EBV), human herpesvirus-8, and human T-cell lymphotropic virus-I, -II, or -III. We used in situ hybridization and immunohistochemical analyses to identify infected cells and viral proteins. We did not detect human herpesvirus-8 or human T-cell lymphotropic viruses in any of the biopsy specimens. However, 12 of 17 (70.5%) biopsy specimens from patients with refractory celiac disease were positive for EBV, compared with 4 of 24 (16.6%) biopsy specimens from controls (P celiac disease and enteropathy-associated T-cell lymphoma. PMID:27033429

  1. Susceptibility of cell lines to avian viruses

    Directory of Open Access Journals (Sweden)

    Simoni Isabela Cristina

    1999-01-01

    Full Text Available The susceptibility of the five cell lines - IB-RS-2, RK-13, Vero, BHK-21, CER - to reovirus S1133 and infectious bursal disease virus (IBDV vaccine GBV-8 strain was studied to better define satisfactory and sensitive cell culture systems. Cultures were compared for presence of CPE, virus titers and detection of viral RNA. CPE and viral RNA were detected in CER and BHK-21 cells after reovirus inoculation and in RK-13 cell line after IBDV inoculation and with high virus titers. Virus replication by production of low virus titers occurred in IB-RS-2 and Vero cells with reovirus and in BHK-21 cell line with IBDV.

  2. Viruses, dendritic cells and the lung

    Directory of Open Access Journals (Sweden)

    Graham Barney S

    2001-06-01

    Full Text Available Abstract The interaction between viruses and dendritic cells (DCs is varied and complex. DCs are key elements in the development of a host response to pathogens such as viruses, but viruses have developed survival tactics to either evade or diminish the immune system that functions to kill and eliminate these micro-organisms. In the present review we summarize current concepts regarding the function of DCs in the immune system, our understanding of how viruses alter DC function to attenuate both the virus-specific and global immune response, and how we may be able to exploit DC function to prevent or treat viral infections.

  3. Oncogenic viruses and cancer

    Institute of Scientific and Technical Information of China (English)

    Guangxiang; George; Luo; Jing-hsiung; James; Ou

    2015-01-01

    <正>This special issue of the journal is dedicated to the important topic of oncogenic viruses and cancer.It contains seven review articles covering all known oncogenic viruses except for human T-lymphotropic virus type1(HTLV-1).These review articles are contributed by experts on specific viruses and their associated human cancers.Viruses account for about 20%of total human cancer cases.Although many viruses can cause various tumors in animals,only seven of them

  4. Early T Cell Recognition of B Cells following Epstein-Barr Virus Infection: Identifying Potential Targets for Prophylactic Vaccination.

    Science.gov (United States)

    Brooks, Jill M; Long, Heather M; Tierney, Rose J; Shannon-Lowe, Claire; Leese, Alison M; Fitzpatrick, Martin; Taylor, Graham S; Rickinson, Alan B

    2016-04-01

    Epstein-Barr virus, a B-lymphotropic herpesvirus, is the cause of infectious mononucleosis, has strong aetiologic links with several malignancies and has been implicated in certain autoimmune diseases. Efforts to develop a prophylactic vaccine to prevent or reduce EBV-associated disease have, to date, focused on the induction of neutralising antibody responses. However, such vaccines might be further improved by inducing T cell responses capable of recognising and killing recently-infected B cells. In that context, EBNA2, EBNA-LP and BHRF1 are the first viral antigens expressed during the initial stage of B cell growth transformation, yet have been poorly characterised as CD8+ T cell targets. Here we describe CD8+ T cell responses against each of these three "first wave" proteins, identifying target epitopes and HLA restricting alleles. While EBNA-LP and BHRF1 each contained one strong CD8 epitope, epitopes within EBNA2 induced immunodominant responses through several less common HLA class I alleles (e.g. B*3801 and B*5501), as well as subdominant responses through common class I alleles (e.g. B7 and C*0304). Importantly, such EBNA2-specific CD8+ T cells recognised B cells within the first day post-infection, prior to CD8+ T cells against well-characterised latent target antigens such as EBNA3B or LMP2, and effectively inhibited outgrowth of EBV-transformed B cell lines. We infer that "first wave" antigens of the growth-transforming infection, especially EBNA2, constitute potential CD8+ T cell immunogens for inclusion in prophylactic EBV vaccine design. PMID:27096949

  5. Early T Cell Recognition of B Cells following Epstein-Barr Virus Infection: Identifying Potential Targets for Prophylactic Vaccination.

    Directory of Open Access Journals (Sweden)

    Jill M Brooks

    2016-04-01

    Full Text Available Epstein-Barr virus, a B-lymphotropic herpesvirus, is the cause of infectious mononucleosis, has strong aetiologic links with several malignancies and has been implicated in certain autoimmune diseases. Efforts to develop a prophylactic vaccine to prevent or reduce EBV-associated disease have, to date, focused on the induction of neutralising antibody responses. However, such vaccines might be further improved by inducing T cell responses capable of recognising and killing recently-infected B cells. In that context, EBNA2, EBNA-LP and BHRF1 are the first viral antigens expressed during the initial stage of B cell growth transformation, yet have been poorly characterised as CD8+ T cell targets. Here we describe CD8+ T cell responses against each of these three "first wave" proteins, identifying target epitopes and HLA restricting alleles. While EBNA-LP and BHRF1 each contained one strong CD8 epitope, epitopes within EBNA2 induced immunodominant responses through several less common HLA class I alleles (e.g. B*3801 and B*5501, as well as subdominant responses through common class I alleles (e.g. B7 and C*0304. Importantly, such EBNA2-specific CD8+ T cells recognised B cells within the first day post-infection, prior to CD8+ T cells against well-characterised latent target antigens such as EBNA3B or LMP2, and effectively inhibited outgrowth of EBV-transformed B cell lines. We infer that "first wave" antigens of the growth-transforming infection, especially EBNA2, constitute potential CD8+ T cell immunogens for inclusion in prophylactic EBV vaccine design.

  6. Isolation and Characterization of a Neuropathogenic Simian Immunodeficiency Virus Derived from a Sooty Mangabey

    OpenAIRE

    Novembre, Francis J; de Rosayro, Juliette; O’Neil, Shawn P.; Anderson, Daniel C.; Klumpp, Sherry A.; McClure, Harold M.

    1998-01-01

    Transfusion of blood from a simian immunodeficiency virus (SIV)- and simian T-cell lymphotropic virus-infected sooty mangabey (designated FGb) to rhesus and pig-tailed macaques resulted in the development of neurologic disease in addition to AIDS. To investigate the role of SIV in neurologic disease, virus was isolated from a lymph node of a pig-tailed macaque (designated PGm) and the cerebrospinal fluid of a rhesus macaque (designated ROn2) and passaged to additional macaques. SIV-related ne...

  7. Neural stem cells attacked by Zika virus.

    Science.gov (United States)

    Nguyen, Ha Nam; Qian, Xuyu; Song, Hongjun; Ming, Guo-Li

    2016-07-01

    The current outbreak of Zika virus-associated diseases in South America and its threat to spread to other parts of the world has emerged as a global health emergency. Insights from cell and animal models to understand how Zika virus causes severe birth defects may lead to treatments and prevention of these diseases. PMID:27283801

  8. Cell Culture for Production of Insecticidal Viruses.

    Science.gov (United States)

    Reid, Steven; Chan, Leslie C L; Matindoost, Leila; Pushparajan, Charlotte; Visnovsky, Gabriel

    2016-01-01

    While large-scale culture of insect cells will need to be conducted using bioreactors up to 10,000 l scale, many of the main challenges for cell culture-based production of insecticidal viruses can be studied using small-scale (20-500 ml) shaker/spinner flasks, either in free suspension or using microcarrier-based systems. These challenges still relate to the development of appropriate cell lines, stability of virus strains in culture, enhancing virus yields per cell, and the development of serum-free media and feeds for the desired production systems. Hence this chapter presents mainly the methods required to work with and analyze effectively insect cell systems using small-scale cultures. Outlined are procedures for quantifying cells and virus and for establishing frozen cells and virus stocks. The approach for maintaining cell cultures and the multiplicity of infection (MOI) and time of infection (TOI) parameters that should be considered for conducting infections are discussed.The methods described relate, in particular, to the suspension culture of Helicoverpa zea and Spodoptera frugiperda cell lines to produce the baculoviruses Helicoverpa armigera nucleopolyhedrovirus, HearNPV, and Anticarsia gemmatalis multicapsid nucleopolyhedrovirus, AgMNPV, respectively, and the production of the nonoccluded Oryctes nudivirus, OrNV, using an adherent coleopteran cell line. PMID:27565495

  9. Oncogenic viruses: Lessons learned using next-generation sequencing technologies.

    Science.gov (United States)

    Flippot, Ronan; Malouf, Gabriel G; Su, Xiaoping; Khayat, David; Spano, Jean-Philippe

    2016-07-01

    Fifteen percent of cancers are driven by oncogenic human viruses. Four of those viruses, hepatitis B virus, human papillomavirus, Merkel cell polyomavirus, and human T-cell lymphotropic virus, integrate the host genome. Viral oncogenesis is the result of epigenetic and genetic alterations that happen during viral integration. So far, little data have been available regarding integration mechanisms and modifications in the host genome. However, the emergence of high-throughput sequencing and bioinformatic tools enables researchers to establish the landscape of genomic alterations and predict the events that follow viral integration. Cooperative working groups are currently investigating these factors in large data sets. Herein, we provide novel insights into the initiating events of cancer onset during infection with integrative viruses. Although much remains to be discovered, many improvements are expected from the clinical point of view, from better prognosis classifications to better therapeutic strategies. PMID:27156225

  10. Human herpesvirus 6 infection after allogeneic stem cell transplantation

    OpenAIRE

    Wang, Fu-Zhang

    1999-01-01

    Human herpesvirus 6 (HHV-6) is a lymphotropic virus mainly infecting T lymphocytes but also other types of cells. Seroepidemiological studies have shown that more than 90% of individuals older than 2 years are seropositive for HHV-6. There are two variants (A and B) of HHV-6, and variant B has been much more often coupled to diseases than variant A. The prevalence of the two variants is still not known since the serological responses can not be differentiated by currently av...

  11. Neoplastic transformation of chimpanzee cells induced by adenovirus type 12--simian virus 40 hybrid virus.

    OpenAIRE

    Rhim, J S; Trimmer, R; Arnstein, P; Huebner, R J

    1981-01-01

    The adenovirus 12--simian virus 40 hybrid virus produced neoplastic transformation of chimpanzee skin fibroblasts in vitro. The transformed fibroblasts showed morphological alteration and became permanent lines. The transformed cells contained both adenovirus 12 and simian virus 40 large tumor antigens and were virus producers. However at passage 9, one line (WES) was found to be a nonproducer, producing neither infectious virus nor virus-specific antigen detectable by the complement fixation...

  12. Psoralen inactivation of influenza and herpes simplex viruses and of virus-infected cells

    International Nuclear Information System (INIS)

    Psoralen compounds covalently bind to nucleic acids when irradiated with long-wavelength ultraviolet light. This treatment can destroy the infectivity of deoxyribonucleic acid and ribonucleic acid viruses. Two psoralen compounds, 4'-hydroxymethyltrioxsalen and 4'-aminomethyltrioxsalen, were used with long-wavelength ultraviolet light to inactivate cell-free herpes simplex and influenza viruses and to render virus-infected cells noninfectious. This method of inactivation was compared with germicidal (short-wavelength) ultraviolet light irradiation. The antigenicity of the treated, virus-infected, antigen-bearing cells was examined by immunofluorescence and radioimmunoassay and by measuring the capacity of the herpes simplex virus-infected cells to stimulate virus-specific lymphocyte proliferation. The infectivity of the virus-infected cells could be totally eliminated without altering their viral antigenicity. The use of psoralen plus long-wavelength ultraviolet light is well suited to the preparation of noninfectious virus antigens and virus antigen-bearing cells for immunological assays

  13. Susceptibility testing of fish cell lines for virus isolation

    DEFF Research Database (Denmark)

    Ariel, Ellen; Skall, Helle Frank; Olesen, Niels Jørgen

    2009-01-01

    Passage of cell cultures may adversely influence cell susceptibility to virus infection through selection of cell clones that thrive in vitro but may not necessarily display high sensitivity to virus infection. Susceptibility to a given virus can therefore vary not only between cell lines and......-cell-culture-adapted" virus by propagating the virus in heterologous cell lines to the one tested. A stock of test virus was produced and stored at - 80 °C and tests were conducted biannually. This procedure becomes complicated when several cell lines are in use and does not account for variation among lineages. In comparing...... cell lineages, we increased the number of isolates of each virus, propagated stocks in a given cell line and tested all lineages of that line in use in the laboratory. Testing of relative cell line susceptibility between laboratories is carried out annually via the Inter-laboratory Proficiency Test...

  14. Cell carriers for oncolytic viruses: current challenges and future directions.

    Science.gov (United States)

    Roy, Dominic G; Bell, John C

    2013-01-01

    The optimal route for clinical delivery of oncolytic viruses is thought to be systemic intravenous injection; however, the immune system is armed with several highly efficient mechanisms to remove pathogens from the circulatory system. To overcome the challenges faced in trying to delivery oncolytic viruses specifically to tumors via the bloodstream, carrier cells have been investigated to determine their suitability as delivery vehicles for systemic administration of oncolytic viruses. Cell carriers protect viruses from neutralization, one of the most limiting aspects of oncolytic virus interaction with the immune system. Cell carriers can also possess inherent tumor tropism, thus directing the delivery of the virus more specifically to a tumor. With preclinical studies already demonstrating the success and feasibility of this approach with multiple oncolytic viruses, clinical evaluation of cell-mediated delivery of viruses is on the horizon. Meanwhile, ongoing preclinical studies are aimed at identifying new cellular vehicles for oncolytic viruses and improving current promising cell carrier platforms. PMID:27512657

  15. Defective interfering particles of Sindbis virus do not interfere with the homologous virus obtained from persistently infected BHK cells but do interfere with Semliki Forest virus.

    OpenAIRE

    Weiss, B; Schlesinger, S

    1981-01-01

    Defective interfering particles derived from wild-type Sindbis virus no longer interfere with the infectious virus cloned from BHK cells persistently infected with Sindbis virus for 16 months. These particles do interfere with the replication of Semliki Forest virus.

  16. Type C virus activation in nontransformed mouse cells by uv-irradiated herpes simplex virus

    International Nuclear Information System (INIS)

    Infection of nontransformed mouse cells with uv-irradiated herpes simplex virus (uv-HSV) resulted in the activation of an endogenous xenotropic (x-tropic) type C virus. Synthesis of type C virus persisted for only a few days, with most of the virus remaining cell associated. The levels of type C virus activated by uv-HSV varied depending on the multiplicity of infection (m.o.i.) and the uv dose. At low uv doses, where cell killing occurred, little or no type C virus synthesis was observed. Maximum levels of type C virus synthesis were observed with the minimum uv dose which eliminated cell killing by HSV. Synthesis of type C virus, albeit at lower levels, was still observed at uv doses beyond those required to prevent cell killing

  17. Molecular Mechanisms of HTLV-1 Cell-to-Cell Transmission

    Directory of Open Access Journals (Sweden)

    Christine Gross

    2016-03-01

    Full Text Available The tumorvirus human T-cell lymphotropic virus type 1 (HTLV-1, a member of the delta-retrovirus family, is transmitted via cell-containing body fluids such as blood products, semen, and breast milk. In vivo, HTLV-1 preferentially infects CD4+ T-cells, and to a lesser extent, CD8+ T-cells, dendritic cells, and monocytes. Efficient infection of CD4+ T-cells requires cell-cell contacts while cell-free virus transmission is inefficient. Two types of cell-cell contacts have been described to be critical for HTLV-1 transmission, tight junctions and cellular conduits. Further, two non-exclusive mechanisms of virus transmission at cell-cell contacts have been proposed: (1 polarized budding of HTLV-1 into synaptic clefts; and (2 cell surface transfer of viral biofilms at virological synapses. In contrast to CD4+ T-cells, dendritic cells can be infected cell-free and, to a greater extent, via viral biofilms in vitro. Cell-to-cell transmission of HTLV-1 requires a coordinated action of steps in the virus infectious cycle with events in the cell-cell adhesion process; therefore, virus propagation from cell-to-cell depends on specific interactions between cellular and viral proteins. Here, we review the molecular mechanisms of HTLV-1 transmission with a focus on the HTLV-1-encoded proteins Tax and p8, their impact on host cell factors mediating cell-cell contacts, cytoskeletal remodeling, and thus, virus propagation.

  18. Canine distemper virus infection leads to an inhibitory phenotype of monocyte-derived dendritic cells in vitro with reduced expression of co-stimulatory molecules and increased interleukin-10 transcription.

    Directory of Open Access Journals (Sweden)

    Visar Qeska

    Full Text Available Canine distemper virus (CDV exhibits a profound lymphotropism that causes immunosuppression and increased susceptibility of affected dogs to opportunistic infections. Similar to human measles virus, CDV is supposed to inhibit terminal differentiation of dendritic cells (DCs, responsible for disturbed repopulation of lymphoid tissues and diminished antigen presenting function in dogs. In order to testify the hypothesis that CDV-infection leads to an impairment of professional antigen presenting cells, canine DCs have been generated from peripheral blood monocytes in vitro and infected with CDV. Virus infection was confirmed and quantified by transmission electron microscopy, CDV-specific immunofluorescence, and virus titration. Flow cytometric analyses revealed a significant down-regulation of the major histocompatibility complex class II and co-stimulatory molecules CD80 and CD86 in CDV-infected DCs, indicative of disturbed antigen presenting capacity. Molecular analyses revealed an increased expression of the immune inhibitory cytokine interleukin-10 in DCs following infection. Results of the present study demonstrate that CDV causes phenotypical changes and altered cytokine expression of DCs, which represent potential mechanisms to evade host immune responses and might contribute to immune dysfunction and virus persistence in canine distemper.

  19. Monitoring virus entry into living cells using DiD-labeled dengue virus particles

    NARCIS (Netherlands)

    Ayala Nunez, Vanesa; Wilschut, Jan; Smit, Jolanda M.

    2011-01-01

    A variety of approaches can be applied to investigate the multiple steps and interactions that occur during virus entry into the host cell. Single-virus tracking is a powerful real-time imaging technique that offers the possibility to monitor virus-cell binding, internalization, intracellular traffi

  20. Measles Virus Induces Functional TRAIL Production by Human Dendritic Cells

    Science.gov (United States)

    Vidalain, Pierre-Olivier; Azocar, Olga; Lamouille, Barbara; Astier, Anne; Rabourdin-Combe, Chantal; Servet-Delprat, Christine

    2000-01-01

    Measles virus infection induces a profound immunosuppression that can lead to serious secondary infections. Here we demonstrate that measles virus induces tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mRNA and protein expression in human monocyte-derived dendritic cells. Moreover, measles virus-infected dendritic cells are shown to be cytotoxic via the TRAIL pathway. PMID:10590149

  1. Measles Virus Induces Functional TRAIL Production by Human Dendritic Cells

    OpenAIRE

    Vidalain, Pierre-Olivier; Azocar, Olga; Lamouille, Barbara; Astier, Anne; Rabourdin-Combe, Chantal; Servet-Delprat, Christine

    2000-01-01

    Measles virus infection induces a profound immunosuppression that can lead to serious secondary infections. Here we demonstrate that measles virus induces tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) mRNA and protein expression in human monocyte-derived dendritic cells. Moreover, measles virus-infected dendritic cells are shown to be cytotoxic via the TRAIL pathway.

  2. Isolation of influenza viruses in MDCK 33016PF cells and clearance of contaminating respiratory viruses.

    Science.gov (United States)

    Roth, Bernhard; Mohr, Hannah; Enders, Martin; Garten, Wolfgang; Gregersen, Jens-Peter

    2012-01-11

    This paper summarizes results obtained by multiplex PCR screening of human clinical samples for respiratory viruses and corresponding data obtained after passaging of virus-positive samples in MDCK 33016PF cells. Using the ResPlexII v2.0 (Qiagen) multiplex PCR, 393 positive results were obtained in 468 clinical samples collected during an influenza season in Germany. The overall distribution of positive results was influenza A 42.0%, influenza B 38.7%, adenovirus 1.5%, bocavirus 0.5%, coronavirus 3.3%, enterovirus 5.6%, metapneumovirus 1.0%, parainfluenza virus 0.8%, rhinovirus 4.1%, and respiratory syncytial virus (RSV) 2.5%. Double infections of influenza virus together with another virus were found for adenovirus B and E, bocavirus, coronavirus, enterovirus and for rhinovirus. These other viruses were rapidly lost upon passages in MDCK 33016PF cells and under conditions as applied to influenza virus passaging. Clinical samples, in which no influenza virus but other viruses were found, were also subject to passages in MDCK 33016PF cells. Using lower inoculum dilutions than those normally applied for preparations containing influenza virus (total dilution of the original sample of ∼10(4)), the positive results for the different viruses turned negative already after 2 or 3 passages in MDCK 33016PF cells. These results demonstrate that, under practical conditions as applied to grow influenza viruses, contaminating viruses can be effectively removed by passages in MDCK cells. In combination with their superior isolation efficiency, MDCK cells appear highly suitable to be used as an alternative to embryonated eggs to isolate and propagate influenza vaccine candidate viruses. PMID:22119922

  3. Selective host range restriction of goat cells for recombinant murine leukemia virus and feline leukemia virus type A.

    OpenAIRE

    Fischinger, P J; Thiel, H J; Blevins, C S; Dunlop, N M

    1981-01-01

    We isolated a strain of normal goat fibroblasts which was uniquely selective in that it allowed the replication of xenotropic murine leukemia virus but not polytropic recombinant murine leukemia virus. In addition, feline leukemia virus type A replication was severely diminished in these goat cells, whereas feline leukemia virus type B and feline endogenous RD114-CCC viruses replicated efficiently. No other known cells exhibit this pattern of virus growth restriction. These goat cells allow t...

  4. Hepatitis C virus host cell interactions uncovered

    DEFF Research Database (Denmark)

    Gottwein, Judith; Bukh, Jens

    2007-01-01

      Insights into virus-host cell interactions as uncovered by Randall et al. (1) in a recent issue of PNAS further our understanding of the hepatitis C virus (HCV) life cycle, persistence, and pathogenesis and might lead to the identification of new therapeutic targets. HCV persistently infects 180...... million individuals worldwide, causing chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. The only approved treatment, combination therapy with IFN- and ribavirin, targets cellular pathways (2); however, a sustained virologic response is achieved only in approximately half of the patients...... treated. Therefore, there is a pressing need for the identification of novel drugs against hepatitis C. Although most research focuses on the development of HCV-specific antivirals, such as protease and polymerase inhibitors (3), cellular targets could be pursued and might allow the development of broad...

  5. Indiscriminate recombination in simian virus 40-infected monkey cells.

    OpenAIRE

    Winocour, E; Keshet, I

    1980-01-01

    DNA transfection of African green monkey BSC-1 cells with simian virus 40 (SV40) DNA and bacterial virus phi X174 replicative form DNA ("cotransfection") yielded stocks containing SV40/phi X174 recombinant virus, which was detected by an infectious-center in situ plaque hybridization procedure and which was sensitive to anti-SV40 antiserum. The recombinant virus replicated during serial passage. Restriction endonuclease cleavage of the SV40/phi X174 DNA indicated that several different types ...

  6. Propagation and Titration of West Nile Virus on Vero Cells.

    Science.gov (United States)

    McAuley, Alexander J; Beasley, David W C

    2016-01-01

    The propagation and titration of viruses are key virological techniques. Unlike other flaviviruses, such as the dengue viruses, West Nile virus (WNV) grows and plaques very efficiently on Vero cells, usually inducing strong cytopathic effect (CPE) and forming clear plaques. Here, we outline the steps for propagating WNV from culture supernatant stocks and homogenized organ/mosquito samples, as well as for determining virus titers in samples by serial-dilution plaque assay using neutral red or crystal violet stains. PMID:27188547

  7. Biopolymer encapsulated live influenza virus as a universal CD8+ T cell vaccine against influenza virus

    OpenAIRE

    Boesteanu, Alina C.; Babu, Nadarajan S.; Wheatley, Margaret; Papazoglou, Elisabeth S.; Katsikis, Peter D.

    2010-01-01

    Current influenza virus vaccines primarily elicit antibodies and can be rendered ineffective by antigenic drift and shift. Vaccines that elicit CD8+ T cell responses targeting less variable proteins may function as universal vaccines that have broad reactivity against different influenza virus strains. To generate such a universal vaccine, we encapsulated live influenza virus in a biopolymer and delivered it to mice subcutaneously. This vaccine was safe, induced potent CD8+ T cell immunity an...

  8. Vaccination against δ-retroviruses: the bovine leukemia virus paradigm.

    Science.gov (United States)

    Gutiérrez, Gerónimo; Rodríguez, Sabrina M; de Brogniez, Alix; Gillet, Nicolas; Golime, Ramarao; Burny, Arsène; Jaworski, Juan-Pablo; Alvarez, Irene; Vagnoni, Lucas; Trono, Karina; Willems, Luc

    2014-06-01

    Bovine leukemia virus (BLV) and human T-lymphotropic virus type 1 (HTLV-1) are closely related d-retroviruses that induce hematological diseases. HTLV-1 infects about 15 million people worldwide, mainly in subtropical areas. HTLV-1 induces a wide spectrum of diseases (e.g., HTLV-associated myelopathy/tropical spastic paraparesis) and leukemia/lymphoma (adult T-cell leukemia). Bovine leukemia virus is a major pathogen of cattle, causing important economic losses due to a reduction in production, export limitations and lymphoma-associated death. In the absence of satisfactory treatment for these diseases and besides the prevention of transmission, the best option to reduce the prevalence of d-retroviruses is vaccination. Here, we provide an overview of the different vaccination strategies in the BLV model and outline key parameters required for vaccine efficacy. PMID:24956179

  9. Vaccination against δ-Retroviruses: The Bovine Leukemia Virus Paradigm

    Directory of Open Access Journals (Sweden)

    Gerónimo Gutiérrez

    2014-06-01

    Full Text Available Bovine leukemia virus (BLV and human T-lymphotropic virus type 1 (HTLV-1 are closely related d-retroviruses that induce hematological diseases. HTLV-1 infects about 15 million people worldwide, mainly in subtropical areas. HTLV-1 induces a wide spectrum of diseases (e.g., HTLV-associated myelopathy/tropical spastic paraparesis and leukemia/lymphoma (adult T-cell leukemia. Bovine leukemia virus is a major pathogen of cattle, causing important economic losses due to a reduction in production, export limitations and lymphoma-associated death. In the absence of satisfactory treatment for these diseases and besides the prevention of transmission, the best option to reduce the prevalence of d-retroviruses is vaccination. Here, we provide an overview of the different vaccination strategies in the BLV model and outline key parameters required for vaccine efficacy.

  10. Cell carriers for oncolytic viruses: current challenges and future directions

    Directory of Open Access Journals (Sweden)

    Roy DG

    2013-10-01

    Full Text Available Dominic G Roy,1,2 John C Bell1–31Centre for Innovative Cancer Therapeutics, Ottawa Hospital Research Institute, 2Department of Biochemistry, Immunology and Microbiology, 3Department of Medicine, University of Ottawa, Ottawa, ON, CanadaAbstract: The optimal route for clinical delivery of oncolytic viruses is thought to be systemic intravenous injection; however, the immune system is armed with several highly efficient mechanisms to remove pathogens from the circulatory system. To overcome the challenges faced in trying to delivery oncolytic viruses specifically to tumors via the bloodstream, carrier cells have been investigated to determine their suitability as delivery vehicles for systemic administration of oncolytic viruses. Cell carriers protect viruses from neutralization, one of the most limiting aspects of oncolytic virus interaction with the immune system. Cell carriers can also possess inherent tumor tropism, thus directing the delivery of the virus more specifically to a tumor. With preclinical studies already demonstrating the success and feasibility of this approach with multiple oncolytic viruses, clinical evaluation of cell-mediated delivery of viruses is on the horizon. Meanwhile, ongoing preclinical studies are aimed at identifying new cellular vehicles for oncolytic viruses and improving current promising cell carrier platforms.Keywords: oncolytic virus, cell carrier, systemic delivery, tumor targeting, cancer

  11. The role of virus-specific human T cells in influenza A virus infection

    OpenAIRE

    Guan, Jing; 管静

    2011-01-01

    Influenza A virus infection is a major cause of human morbidity and mortality. T cell immunity is believed to play critical roles for host defenses against influenza A infection. Once intracellular influenza A infection is established, viral clearance is mainly dependent on virus-specific CD8+ T cells. CD4+ T cells are important for adaptive immunity to natural influenza A infection or vaccination by providing help to B cells for antibody production and also providing help...

  12. Dissecting the Cell Entry Pathway of Dengue Virus by Single-Particle Tracking in Living Cells

    NARCIS (Netherlands)

    van der Schaar, Hilde M.; Rust, Michael J.; Chen, Chen; van der Ende-Metselaar, Heidi; Wilschut, Jan; Zhuang, Xiaowei; Smit, Jolanda M.

    2008-01-01

    Dengue virus (DENV) is an enveloped RNA virus that causes the most common arthropod-borne infection worldwide. The mechanism by which DENV infects the host cell remains unclear. In this work, we used live-cell imaging and single-virus tracking to investigate the cell entry, endocytic trafficking, an

  13. Persistent, triple-virus co-infections in mosquito cells

    Directory of Open Access Journals (Sweden)

    Malasit Prida

    2010-01-01

    Full Text Available Abstract Background It is known that insects and crustaceans can carry simultaneous, active infections of two or more viruses without showing signs of disease, but it was not clear whether co-infecting viruses occupied the same cells or different cells in common target tissues. Our previous work showed that successive challenge of mosquito cell cultures followed by serial, split-passage resulted in stabilized cultures with 100% of the cells co-infected with Dengue virus (DEN and an insect parvovirus (densovirus (DNV. By addition of Japanese encephalitis virus (JE, we tested our hypothesis that stable, persistent, triple-virus co-infections could be obtained by the same process. Results Using immunocytochemistry by confocal microscopy, we found that JE super-challenge of cells dually infected with DEN and DNV resulted in stable cultures without signs of cytopathology, and with 99% of the cells producing antigens of the 3 viruses. Location of antigens for all 3 viruses in the triple co-infections was dominant in the cell nuclei. Except for DNV, this differed from the distribution in cells persistently infected with the individual viruses or co-infected with DNV and DEN. The dependence of viral antigen distribution on single infection or co-infection status suggested that host cells underwent an adaptive process to accommodate 2 or more viruses. Conclusions Individual mosquito cells can accommodate at least 3 viruses simultaneously in an adaptive manner. The phenomenon provides an opportunity for genetic exchange between diverse viruses and it may have important medical and veterinary implications for arboviruses.

  14. Human muscle satellite cells as targets of Chikungunya virus infection.

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    Simona Ozden

    Full Text Available BACKGROUND: Chikungunya (CHIK virus is a mosquito-transmitted alphavirus that causes in humans an acute infection characterised by fever, polyarthralgia, head-ache, and myalgia. Since 2005, the emergence of CHIK virus was associated with an unprecedented magnitude outbreak of CHIK disease in the Indian Ocean. Clinically, this outbreak was characterized by invalidating poly-arthralgia, with myalgia being reported in 97.7% of cases. Since the cellular targets of CHIK virus in humans are unknown, we studied the pathogenic events and targets of CHIK infection in skeletal muscle. METHODOLOGY/PRINCIPAL FINDINGS: Immunohistology on muscle biopsies from two CHIK virus-infected patients with myositic syndrome showed that viral antigens were found exclusively inside skeletal muscle progenitor cells (designed as satelllite cells, and not in muscle fibers. To evaluate the ability of CHIK virus to replicate in human satellite cells, we assessed virus infection on primary human muscle cells; viral growth was observed in CHIK virus-infected satellite cells with a cytopathic effect, whereas myotubes were essentially refractory to infection. CONCLUSIONS/SIGNIFICANCE: This report provides new insights into CHIK virus pathogenesis, since it is the first to identify a cellular target of CHIK virus in humans and to report a selective infection of muscle satellite cells by a viral agent in humans.

  15. Detection of a Novel Bovine Lymphotropic Herpesvirus

    OpenAIRE

    Rovnak, Joel; Quackenbush, Sandra L.; Reyes, Richard A.; Baines, Joel D.; Parrish, Colin R.; Casey, James W.

    1998-01-01

    Degenerate PCR primers which amplify a conserved region of the DNA polymerase genes of the herpesvirus family were used to provide sequence evidence for a new bovine herpesvirus in bovine B-lymphoma cells and peripheral blood mononuclear cells (PBMC). The sequence of the resultant amplicon was found to be distinct from those of known herpesvirus isolates. Alignment of amino acid sequences demonstrated 70% identity with ovine herpesvirus 2, 69% with alcelaphine herpesvirus 1, 65% with bovine h...

  16. Human T cell leukemia virus type I and neurologic disease: events in bone marrow, peripheral blood, and central nervous system during normal immune surveillance and neuroinflammation.

    Science.gov (United States)

    Grant, Christian; Barmak, Kate; Alefantis, Timothy; Yao, Jing; Jacobson, Steven; Wigdahl, Brian

    2002-02-01

    Human T cell lymphotropic/leukemia virus type I (HTLV-I) has been identified as the causative agent of both adult T cell leukemia (ATL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Although the exact sequence of events that occur during the early stages of infection are not known in detail, the initial route of infection may predetermine, along with host, environmental, and viral factors, the subset of target cells and/or the primary immune response encountered by HTLV-I, and whether an HTLV-I-infected individual will remain asymptomatic, develop ATL, or progress to the neuroinflammatory disease, HAM/TSP. Although a large number of studies have indicated that CD4(+) T cells represent an important target for HTLV-I infection in the peripheral blood (PB), additional evidence has accumulated over the past several years demonstrating that HTLV-I can infect several additional cellular compartments in vivo, including CD8(+) T lymphocytes, PB monocytes, dendritic cells, B lymphocytes, and resident central nervous system (CNS) astrocytes. More importantly, extensive latent viral infection of the bone marrow, including cells likely to be hematopoietic progenitor cells, has been observed in individuals with HAM/TSP as well as some asymptomatic carriers, but to a much lesser extent in individuals with ATL. Furthermore, HTLV-I(+) CD34(+) hematopoietic progenitor cells can maintain the intact proviral genome and initiate viral gene expression during the differentiation process. Introduction of HTLV-I-infected bone marrow progenitor cells into the PB, followed by genomic activation and low level viral gene expression may lead to an increase in proviral DNA load in the PB, resulting in a progressive state of immune dysregulation including the generation of a detrimental cytotoxic Tax-specific CD8(+) T cell population, anti-HTLV-I antibodies, and neurotoxic cytokines involved in disruption of myelin-producing cells and neuronal degradation

  17. Molecular cloning of human T-cell lymphotrophic virus type I-like proviral genome from the peripheral lymphocyte DNA of a patient with chronic neurologic disorders

    International Nuclear Information System (INIS)

    Human T-cell lymphotropic virus type 1 (HTLV-I), the etiologic agent of human T-cell leukemia, has recently been shown to be associated with neurologic disorders such as tropical spastic paraparesis, HTLV-associated myelopathy, and possibly with multiple sclerosis. In this communication, the authors have examined one specific case of neurologic disorder that can be classified as multiple sclerosis or tropical spastic paraparesis. The patient suffering from chronic neurologic disorder was found to contain antibodies to HTLV-I envelope and gag proteins in his serum and cerebrospinal fluid. Lymphocytes from peripheral blood and cerebrospinal fluid of the patient were shown to express viral RNA sequences by in situ hybridization. Southern blot analysis of the patient lymphocyte DNA revealed the presence of HTLV-I-related sequences. Blot-hybridization analysis of the RNA from fresh peripheral lymphocytes stimulated with interleukin 2 revealed the presence of abundant amounts of genomic viral RNA with little or no subgenomic RNA. They have clones the proviral genome from the DNA of the peripheral lymphocytes and determined its restriction map. This analysis shows that this proviral genome is very similar if not identical to that of the prototype HTLV-I genome

  18. Understanding How Zika Virus Enters and Infects Neural Target Cells.

    Science.gov (United States)

    Miner, Jonathan J; Diamond, Michael S

    2016-05-01

    Zika virus is a mosquito-transmitted flavivirus that has become a public health concern because of its ability to cause microcephaly. In this issue of Cell Stem Cell, Tang et al. (2016) and Nowakowski et al. (2016) use human neural stem cell models and single-cell RNA sequencing to investigate Zika virus tropism and potential entry receptors. PMID:27152436

  19. Detection of hepatitis B virus DNA in mononuclear blood cells.

    OpenAIRE

    Pontisso, P; Poon, M C; Tiollais, P.; Brechot, C

    1984-01-01

    The Southern transfer hybridisation technique was used to test mononuclear blood cells for hepatitis B virus DNA. Viral DNA sequences were detected in mononuclear cells of 10 out of 16 patients with hepatitis B virus infection and in none of 21 normal controls. Blood contamination was excluded by the absence of hepatitis B virus DNA in the corresponding serum samples in all cases. Free monomeric hepatitis B virus DNA was found in three patients positive for hepatitis Be antigen (HBeAg) and on...

  20. Tumor cell marker PVRL4 (nectin 4 is an epithelial cell receptor for measles virus.

    Directory of Open Access Journals (Sweden)

    Ryan S Noyce

    2011-08-01

    Full Text Available Vaccine and laboratory adapted strains of measles virus can use CD46 as a receptor to infect many human cell lines. However, wild type isolates of measles virus cannot use CD46, and they infect activated lymphocytes, dendritic cells, and macrophages via the receptor CD150/SLAM. Wild type virus can also infect epithelial cells of the respiratory tract through an unidentified receptor. We demonstrate that wild type measles virus infects primary airway epithelial cells grown in fetal calf serum and many adenocarcinoma cell lines of the lung, breast, and colon. Transfection of non-infectable adenocarcinoma cell lines with an expression vector encoding CD150/SLAM rendered them susceptible to measles virus, indicating that they were virus replication competent, but lacked a receptor for virus attachment and entry. Microarray analysis of susceptible versus non-susceptible cell lines was performed, and comparison of membrane protein gene transcripts produced a list of 11 candidate receptors. Of these, only the human tumor cell marker PVRL4 (Nectin 4 rendered cells amenable to measles virus infections. Flow cytometry confirmed that PVRL4 is highly expressed on the surfaces of susceptible lung, breast, and colon adenocarcinoma cell lines. Measles virus preferentially infected adenocarcinoma cell lines from the apical surface, although basolateral infection was observed with reduced kinetics. Confocal immune fluorescence microscopy and surface biotinylation experiments revealed that PVRL4 was expressed on both the apical and basolateral surfaces of these cell lines. Antibodies and siRNA directed against PVRL4 were able to block measles virus infections in MCF7 and NCI-H358 cancer cells. A virus binding assay indicated that PVRL4 was a bona fide receptor that supported virus attachment to the host cell. Several strains of measles virus were also shown to use PVRL4 as a receptor. Measles virus infection reduced PVRL4 surface expression in MCF7 cells, a

  1. The ancient Virus World and evolution of cells

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    Dolja Valerian V

    2006-09-01

    Full Text Available Abstract Background Recent advances in genomics of viruses and cellular life forms have greatly stimulated interest in the origins and evolution of viruses and, for the first time, offer an opportunity for a data-driven exploration of the deepest roots of viruses. Here we briefly review the current views of virus evolution and propose a new, coherent scenario that appears to be best compatible with comparative-genomic data and is naturally linked to models of cellular evolution that, from independent considerations, seem to be the most parsimonious among the existing ones. Results Several genes coding for key proteins involved in viral replication and morphogenesis as well as the major capsid protein of icosahedral virions are shared by many groups of RNA and DNA viruses but are missing in cellular life forms. On the basis of this key observation and the data on extensive genetic exchange between diverse viruses, we propose the concept of the ancient virus world. The virus world is construed as a distinct contingent of viral genes that continuously retained its identity throughout the entire history of life. Under this concept, the principal lineages of viruses and related selfish agents emerged from the primordial pool of primitive genetic elements, the ancestors of both cellular and viral genes. Thus, notwithstanding the numerous gene exchanges and acquisitions attributed to later stages of evolution, most, if not all, modern viruses and other selfish agents are inferred to descend from elements that belonged to the primordial genetic pool. In this pool, RNA viruses would evolve first, followed by retroid elements, and DNA viruses. The Virus World concept is predicated on a model of early evolution whereby emergence of substantial genetic diversity antedates the advent of full-fledged cells, allowing for extensive gene mixing at this early stage of evolution. We outline a scenario of the origin of the main classes of viruses in conjunction

  2. Radiation induction of endogenous type C virus from mouse cells transformed in vitro by murine sarcoma virus

    International Nuclear Information System (INIS)

    Cell lines from AKR and BALB/c mouse embryos were compared for their sensitivity to x-ray induction of endogenous type C virus. K-Balb cells, a Balb/3T3 cell line nonproductively transformed by Kirsten murine sarcoma virus, were found to be sensitive to s-irradiation. At a dose as low as 50 R, x-rays induced virus expression in K-Balb cells, and the induction frequency increased with increasing dose of x-rays up to 400 R. Among two classes of inducible endogenous viruses carried by K-Balb cells, only Balb:virus-2 was activated by x-irradiation, whereas both Balb:virus-1 and Balb:virus-2 were activated after the cells were treated with 5-iodo-2'-deoxyuridine. UV light and 4-nitroquinoline 1-oxide were also shown to induce virus expression in K-Balb cells

  3. The cell biology of Tobacco mosaic virus replication and movement

    OpenAIRE

    Liu, Chengke; Richard S Nelson

    2013-01-01

    Successful systemic infection of a plant by Tobacco mosaic virus (TMV) requires three processes that repeat over time: initial establishment and accumulation in invaded cells, intercellular movement, and systemic transport. Accumulation and intercellular movement of TMV necessarily involves intracellular transport by complexes containing virus and host proteins and virus RNA during a dynamic process that can be visualized. Multiple membranes appear to assist TMV accumulation, while membranes,...

  4. Cell-free translation of bovine viral diarrhea virus RNA.

    OpenAIRE

    Purchio, A F; Larson, R.; Torborg, L L; Collett, M S

    1984-01-01

    Bovine viral diarrhea virus RNA was translated in a reticulocyte cell-free protein synthesizing system. The purified, 8.2-kilobase, virus-specific RNA species was unable to serve an an efficient message unless it was denatured immediately before translation. In this case, several polypeptides, ranging in molecular weight from 50,000 to 150,000 and most of which were immunoprecipitated by bovine viral diarrhea virus-specific antiserum, were synthesized in vitro. When polyribosomes were used to...

  5. Early Events in Chikungunya Virus Infection-From Virus Cell Binding to Membrane Fusion.

    Science.gov (United States)

    van Duijl-Richter, Mareike K S; Hoornweg, Tabitha E; Rodenhuis-Zybert, Izabela A; Smit, Jolanda M

    2015-07-01

    Chikungunya virus (CHIKV) is a rapidly emerging mosquito-borne alphavirus causing millions of infections in the tropical and subtropical regions of the world. CHIKV infection often leads to an acute self-limited febrile illness with debilitating myalgia and arthralgia. A potential long-term complication of CHIKV infection is severe joint pain, which can last for months to years. There are no vaccines or specific therapeutics available to prevent or treat infection. This review describes the critical steps in CHIKV cell entry. We summarize the latest studies on the virus-cell tropism, virus-receptor binding, internalization, membrane fusion and review the molecules and compounds that have been described to interfere with virus cell entry. The aim of the review is to give the reader a state-of-the-art overview on CHIKV cell entry and to provide an outlook on potential new avenues in CHIKV research. PMID:26198242

  6. Early Events in Chikungunya Virus Infection—From Virus CellBinding to Membrane Fusion

    Directory of Open Access Journals (Sweden)

    Mareike K. S. van Duijl-Richter

    2015-07-01

    Full Text Available Chikungunya virus (CHIKV is a rapidly emerging mosquito-borne alphavirus causing millions of infections in the tropical and subtropical regions of the world. CHIKV infection often leads to an acute self-limited febrile illness with debilitating myalgia and arthralgia. A potential long-term complication of CHIKV infection is severe joint pain, which can last for months to years. There are no vaccines or specific therapeutics available to prevent or treat infection. This review describes the critical steps in CHIKV cell entry. We summarize the latest studies on the virus-cell tropism, virus-receptor binding, internalization, membrane fusion and review the molecules and compounds that have been described to interfere with virus cell entry. The aim of the review is to give the reader a state-of-the-art overview on CHIKV cell entry and to provide an outlook on potential new avenues in CHIKV research.

  7. Human Vγ9Vδ2-T cells efficiently kill influenza virus-infected lung alveolar epithelial cells

    OpenAIRE

    LI Hong; Xiang, Zheng; Feng, Ting; Li, Jinrong; Liu, Yinping; Fan, Yingying; Lu, Qiao; Yin, Zhongwei; Yu, Meixing; Shen, Chongyang; Tu, Wenwei

    2013-01-01

    γδ-T cells play an indispensable role in host defense against different viruses, including influenza A virus. However, whether these cells have cytotoxic activity against influenza virus-infected lung alveolar epithelial cells and subsequently contribute to virus clearance remains unknown. Using influenza virus-infected A549 cells, human lung alveolar epithelial cells, we investigated the cytotoxic activity of aminobisphosphonate pamidronate (PAM)-expanded human Vγ9Vδ2-T cells and their under...

  8. Susceptibility of human primary neuronal cells to Xenotropic Murine Leukemia Virus-related (XMRV virus infection

    Directory of Open Access Journals (Sweden)

    Girisetty Mohan

    2011-09-01

    Full Text Available Abstract Background Xenotropic Murine Leukemia Virus-related (XMRV virus is a recently identified mouse gammaretrovirus that has the ability to infect certain human cells. In this study, we investigated the susceptibility of primary neuronal cell types to infection with XMRV. Findings We observed that the human primary progenitors, progenitor-derived neurons, and progenitor-derived astrocytes supported XMRV multiplication. Interestingly, both progenitors and progenitor-derived neurons were more susceptible compared with progenitor-derived astrocytes. In addition, XMRV-infected Jurkat cells were able to transmit infection to neuronal cells. Conclusions These data suggest that neuronal cells are susceptible for XMRV infection.

  9. Viruses and cells intertwined since the dawn of evolution

    OpenAIRE

    DURZYŃSKA, JULIA; Goździcka-Józefiak, Anna

    2015-01-01

    Many attempts have been made to define nature of viruses and to uncover their origin. Our aim within this work was to show that there are different perceptions of viruses and many concepts to explain their emergence: the virus-first concept (also called co-evolution), the escape and the reduction theories. Moreover, a relatively new concept of polyphyletic virus origin called “three RNA cells, three DNA viruses” proposed by Forterre is described herein. In this paper, not only is each thesis ...

  10. Diagnostic approaches for viruses and prions in stem cell banks

    International Nuclear Information System (INIS)

    Some stem cell lines may contain an endogenous virus or can be contaminated with exogenous viruses (even of animal origin) and may secrete viral particles or express viral antigens on their surface. Moreover, certain biotechnological products (e.g. bovine fetal serum, murine feeder cells) may contain prion particles. Viral and prion contamination of cell cultures and 'feeder' cells, which is a common risk in all biotechnological products derived from the cell lines, is the most challenging and potentially serious outcome to address, due to the difficulty involved in virus and prion detection and the potential to cause serious disease in recipients of these cell products. Stem cell banks should introduce adequate quality assurance programs like the microbiological control program and can provide researchers with valuable support in the standardization and safety of procedures and protocols used for the viral and prion testing and in validation programs to assure the quality and safety of the cells

  11. Modelling Spread of Oncolytic Viruses in Heterogeneous Cell Populations

    Science.gov (United States)

    Ellis, Michael; Dobrovolny, Hana

    2014-03-01

    One of the most promising areas in current cancer research and treatment is the use of viruses to attack cancer cells. A number of oncolytic viruses have been identified to date that possess the ability to destroy or neutralize cancer cells while inflicting minimal damage upon healthy cells. Formulation of predictive models that correctly describe the evolution of infected tumor systems is critical to the successful application of oncolytic virus therapy. A number of different models have been proposed for analysis of the oncolytic virus-infected tumor system, with approaches ranging from traditional coupled differential equations such as the Lotka-Volterra predator-prey models, to contemporary modeling frameworks based on neural networks and cellular automata. Existing models are focused on tumor cells and the effects of virus infection, and offer the potential for improvement by including effects upon normal cells. We have recently extended the traditional framework to a 2-cell model addressing the full cellular system including tumor cells, normal cells, and the impacts of viral infection upon both populations. Analysis of the new framework reveals complex interaction between the populations and potential inability to simultaneously eliminate the virus and tumor populations.

  12. Lesões dermatológicas em pacientes infectados pelo vírus linfotrópico humano de células T do tipo 1 (HTLV-1 Dermatologic lesions in patients infected with the human T-cell lymphotropic vírus type 1 (HTLV-1

    Directory of Open Access Journals (Sweden)

    Vandack Nobre

    2005-02-01

    Full Text Available O vírus linfotrópico humano de células T do tipo 1 (HTLV-1 é o primeiro retrovírus isolado do ser humano. Descreveu-se, em pouco tempo, o seu papel etiológico em algumas doenças, com destaque para a leucemia/linfoma de células T do adulto (ATLL, a mielopatia associada ao HTLV-1/paraparesia espástica tropical (HAM/TSP e a uveíte associada ao HTLV-1 (HAU. Na década de 90, o HTLV-1 foi associado a eczema grave da infância, conhecido como dermatite infecciosa (DI. Desde então, diversos outros tipos de lesões cutâneas têm sido observados em pacientes infectados pelo HTLV-1, em especial, nos doentes de HAM/TSP ou de ATLL. Porém, mesmo portadores assintomáticos do vírus apresentam doenças dermatológicas. Excetuando-se a dermatite infecciosa, não há lesão da pele específica da infecção pelo HTLV-1. Aqui, os autores apresentam as principais lesões dermatológicas descritas em pacientes infectados pelo HTLV-1, destacando o valor epidemiológico e clínico desses achados.Human T-cell Lymphotropic vírus type I (HTLV-1 was the first human retrovírus described. Some time after its discovery a group of diseases were related to this vírus, such as, adult T-cell leukemia lymphoma (ATLL, HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP and HTLV-1 associated uveitis (HAU. In the nineties, HTLV-1 was associated to a severe eczema of children, called infective dermatitis (ID. Since then, several other skin manifestations have been observed in HTLV-1-infected individuals, particularly in patients with ATLL or HAM/TSP. However, according to some reports, dermatologic lesions are also common in asymptomatic HTLV-1 carriers. Besides ID, all other skin lesions reported are nonspecific. The aim of this review is to outline the dermatologic manifestations reported in HTLV-1 infected patients, emphasizing the clinical and epidemiological value of these findings.

  13. Vaccination against δ−Retroviruses: The Bovine Leukemia Virus Paradigm

    Science.gov (United States)

    Gutiérrez, Gerónimo; Rodríguez, Sabrina M.; de Brogniez, Alix; Gillet, Nicolas; Golime, Ramarao; Burny, Arsène; Jaworski, Juan-Pablo; Alvarez, Irene; Vagnoni, Lucas; Trono, Karina; Willems, Luc

    2014-01-01

    Bovine leukemia virus (BLV) and human T-lymphotropic virus type 1 (HTLV-1) are closely related δ-retroviruses that induce hematological diseases. HTLV-1 infects about 15 million people worldwide, mainly in subtropical areas. HTLV-1 induces a wide spectrum of diseases (e.g., HTLV-associated myelopathy/tropical spastic paraparesis) and leukemia/lymphoma (adult T-cell leukemia). Bovine leukemia virus is a major pathogen of cattle, causing important economic losses due to a reduction in production, export limitations and lymphoma-associated death. In the absence of satisfactory treatment for these diseases and besides the prevention of transmission, the best option to reduce the prevalence of δ-retroviruses is vaccination. Here, we provide an overview of the different vaccination strategies in the BLV model and outline key parameters required for vaccine efficacy. PMID:24956179

  14. Ultrastructure of Zika virus particles in cell cultures

    Science.gov (United States)

    Barreto-Vieira, Debora Ferreira; Barth, Ortrud Monika; da Silva, Marcos Alexandre Nunes; Santos, Carolina Cardoso; Santos, Aline da Silva; F, Joaquim Batista; de Filippis, Ana Maria Bispo

    2016-01-01

    Zika virus (ZIKV) has infected thousands of Brazilian people and spread to other American countries since 2015. The introduction of ZIKV brought a strong impact to public health in Brazil. It is of utmost importance to identify a susceptible cell line that will enable the isolation and identification of the virus from patient samples, viral mass production, and testing of drug and vaccine candidates. Besides real-time reverse transcriptase polymerase chain reaction diagnosis for detecting the viral genome, virus isolation in cell lines was useful in order to study the structure of the viral particle and its behaviour inside cells. Analysis of ZIKV infected cell lines was achieved using transmission electron microscopy (TEM). Blood was obtained from a Brazilian patient during the first days after presenting with signs of the disease, and ZIKV from the patient’s blood was isolated in the C6/36 mosquito cell line. Afterwards, Vero cells were inoculated with the viral suspension, fixed six days after inoculation, embedded in polymers, and ultra-thin cut. Like dengue viruses, this flavivirus showed numerous virus particles present inside cellular vesicles thereby confirming the susceptibility of the Vero cell line to ZIKV replication. TEM is a unique technique available to make the virus visible.

  15. Ultrastructure of Zika virus particles in cell cultures.

    Science.gov (United States)

    Barreto-Vieira, Debora Ferreira; Barth, Ortrud Monika; Silva, Marcos Alexandre Nunes da; Santos, Carolina Cardoso; Santos, Aline da Silva; F, Joaquim Batista; Filippis, Ana Maria Bispo de

    2016-08-01

    Zika virus (ZIKV) has infected thousands of Brazilian people and spread to other American countries since 2015. The introduction of ZIKV brought a strong impact to public health in Brazil. It is of utmost importance to identify a susceptible cell line that will enable the isolation and identification of the virus from patient samples, viral mass production, and testing of drug and vaccine candidates. Besides real-time reverse transcriptase polymerase chain reaction diagnosis for detecting the viral genome, virus isolation in cell lines was useful in order to study the structure of the viral particle and its behaviour inside cells. Analysis of ZIKV infected cell lines was achieved using transmission electron microscopy (TEM). Blood was obtained from a Brazilian patient during the first days after presenting with signs of the disease, and ZIKV from the patient's blood was isolated in the C6/36 mosquito cell line. Afterwards, Vero cells were inoculated with the viral suspension, fixed six days after inoculation, embedded in polymers, and ultra-thin cut. Like dengue viruses, this flavivirus showed numerous virus particles present inside cellular vesicles thereby confirming the susceptibility of the Vero cell line to ZIKV replication. TEM is a unique technique available to make the virus visible. PMID:27581122

  16. Hepatitis C virus cell-cell transmission and resistance to direct-acting antiviral agents.

    Directory of Open Access Journals (Sweden)

    Fei Xiao

    2014-05-01

    Full Text Available Hepatitis C virus (HCV is transmitted between hepatocytes via classical cell entry but also uses direct cell-cell transfer to infect neighboring hepatocytes. Viral cell-cell transmission has been shown to play an important role in viral persistence allowing evasion from neutralizing antibodies. In contrast, the role of HCV cell-cell transmission for antiviral resistance is unknown. Aiming to address this question we investigated the phenotype of HCV strains exhibiting resistance to direct-acting antivirals (DAAs in state-of-the-art model systems for cell-cell transmission and spread. Using HCV genotype 2 as a model virus, we show that cell-cell transmission is the main route of viral spread of DAA-resistant HCV. Cell-cell transmission of DAA-resistant viruses results in viral persistence and thus hampers viral eradication. We also show that blocking cell-cell transmission using host-targeting entry inhibitors (HTEIs was highly effective in inhibiting viral dissemination of resistant genotype 2 viruses. Combining HTEIs with DAAs prevented antiviral resistance and led to rapid elimination of the virus in cell culture model. In conclusion, our work provides evidence that cell-cell transmission plays an important role in dissemination and maintenance of resistant variants in cell culture models. Blocking virus cell-cell transmission prevents emergence of drug resistance in persistent viral infection including resistance to HCV DAAs.

  17. Antitumor efficacy of vaccinia virus-modified tumor cell vaccine

    International Nuclear Information System (INIS)

    The antitumor efficacies of vaccinia virus-modified tumor cell vaccines were examined in murine syngeneic MH134 and X5563 tumor cells. UV-inactivated vaccinia virus was inoculated i.p. into C3H/HeN mice that had received whole body X-irradiation at 150 rads. After 3 weeks, the vaccines were administered i.p. 3 times at weekly intervals. One week after the last injection, mice were challenged i.p. with various doses of syngeneic MH134 or X5563 viable tumor cells. Four methods were used for preparing tumor cell vaccines: X-ray irradiation; fixation with paraformaldehyde for 1 h or 3 months; and purification of the membrane fraction. All four vaccines were effective, but the former two vaccines were the most effective. A mixture of the membrane fraction of untreated tumor cells and UV-inactivated vaccinia virus also had an antitumor effect. These results indicate that vaccine with the complete cell structure is the most effective. The membrane fraction of UV-inactivated vaccinia virus-absorbed tumor cells was also effective. UV-inactivated vaccinia virus can react with not only intact tumor cells but also the purified membrane fraction of tumor cells and augment antitumor activity

  18. Dengue Virus Infection Perturbs Lipid Homeostasis in Infected Mosquito Cells

    Energy Technology Data Exchange (ETDEWEB)

    Perera, Rushika M.; Riley, Catherine; Isaac, Georgis; Hopf- Jannasch, Amber; Moore, Ronald J.; Weitz, Karl K.; Pasa-Tolic, Ljiljana; Metz, Thomas O.; Adamec, Jiri; Kuhn, Richard J.

    2012-03-22

    Dengue virus causes {approx}50-100 million infections per year and thus is considered one of the most aggressive arthropod-borne human pathogen worldwide. During its replication, dengue virus induces dramatic alterations in the intracellular membranes of infected cells. This phenomenon is observed both in human and vector-derived cells. Using high-resolution mass spectrometry of mosquito cells, we show that this membrane remodeling is directly linked to a unique lipid repertoire induced by dengue virus infection. Specifically, 15% of the metabolites detected were significantly different between DENV infected and uninfected cells while 85% of the metabolites detected were significantly different in isolated replication complex membranes. Furthermore, we demonstrate that intracellular lipid redistribution induced by the inhibition of fatty acid synthase, the rate-limiting enzyme in lipid biosynthesis, is sufficient for cell survival but is inhibitory to dengue virus replication. Lipids that have the capacity to destabilize and change the curvature of membranes as well as lipids that change the permeability of membranes are enriched in dengue virus infected cells. Several sphingolipids and other bioactive signaling molecules that are involved in controlling membrane fusion, fission, and trafficking as well as molecules that influence cytoskeletal reorganization are also up regulated during dengue infection. These observations shed light on the emerging role of lipids in shaping the membrane and protein environments during viral infections and suggest membrane-organizing principles that may influence virus-induced intracellular membrane architecture.

  19. Effects of chloroquine and cytochalasin B on the infection of cells by Sindbis virus and vesicular stomatitis virus.

    OpenAIRE

    Coombs, K; Mann, E; Edwards, J; Brown, D T

    1981-01-01

    The effects of cytochalasin B and chloroquine on the process of endocytosis of Sindbis virus particles and polystyrene spheres were determined by electron microscopy. The effects of these agents on the process of infection (attachment, penetration, and uncoating) of BHK-21 cells by Sindbis virus and vesicular stomatitis virus were also determined. Cytochalasin B completely blocked ingestion of Sindbis virus particles or latex spheres by BHK cells but had no effect on the ability of Sindbis vi...

  20. Localization of influenza virus proteins to nuclear dot 10 structures in influenza virus-infected cells

    International Nuclear Information System (INIS)

    We studied influenza virus M1 protein by generating HeLa and MDCK cell lines that express M1 genetically fused to green fluorescent protein (GFP). GFP-M1 was incorporated into virions produced by influenza virus infected MDCK cells expressing the fusion protein indicating that the fusion protein is at least partially functional. Following infection of either HeLa or MDCK cells with influenza A virus (but not influenza B virus), GFP-M1 redistributes from its cytosolic/nuclear location and accumulates in nuclear dots. Immunofluorescence revealed that the nuclear dots represent nuclear dot 10 (ND10) structures. The colocalization of authentic M1, as well as NS1 and NS2 protein, with ND10 was confirmed by immunofluorescence following in situ isolation of ND10. These findings demonstrate a previously unappreciated involvement of influenza virus with ND10, a structure involved in cellular responses to immune cytokines as well as the replication of a rapidly increasing list of viruses

  1. Reference gene selection for quantitative real-time PCR analysis in virus infected cells: SARS corona virus, Yellow fever virus, Human Herpesvirus-6, Camelpox virus and Cytomegalovirus infections

    Directory of Open Access Journals (Sweden)

    Müller Marcel A

    2005-02-01

    Full Text Available Abstract Ten potential reference genes were compared for their use in experiments investigating cellular mRNA expression of virus infected cells. Human cell lines were infected with Cytomegalovirus, Human Herpesvirus-6, Camelpox virus, SARS coronavirus or Yellow fever virus. The expression levels of these genes and the viral replication were determined by real-time PCR. Genes were ranked by the BestKeeper tool, the GeNorm tool and by criteria we reported previously. Ranking lists of the genes tested were tool dependent. However, over all, β-actin is an unsuitable as reference gene, whereas TATA-Box binding protein and peptidyl-prolyl-isomerase A are stable reference genes for expression studies in virus infected cells.

  2. RNA Viruses: ROS-Mediated Cell Death

    OpenAIRE

    Mohammad Latif Reshi; Yi-Che Su; Jiann-Ruey Hong

    2014-01-01

    Reactive oxygen species (ROS) are well known for being both beneficial and deleterious. The main thrust of this review is to investigate the role of ROS in ribonucleic acid (RNA) virus pathogenesis. Much evidences has accumulated over the past decade, suggesting that patients infected with RNA viruses are under chronic oxidative stress. Changes to the body's antioxidant defense system, in relation to SOD, ascorbic acid, selenium, carotenoids, and glutathione, have been reported in various tis...

  3. Molecular Mechanisms of HTLV-1 Cell-to-Cell Transmission.

    Science.gov (United States)

    Gross, Christine; Thoma-Kress, Andrea K

    2016-01-01

    The tumorvirus human T-cell lymphotropic virus type 1 (HTLV-1), a member of the delta-retrovirus family, is transmitted via cell-containing body fluids such as blood products, semen, and breast milk. In vivo, HTLV-1 preferentially infects CD4⁺ T-cells, and to a lesser extent, CD8⁺ T-cells, dendritic cells, and monocytes. Efficient infection of CD4⁺ T-cells requires cell-cell contacts while cell-free virus transmission is inefficient. Two types of cell-cell contacts have been described to be critical for HTLV-1 transmission, tight junctions and cellular conduits. Further, two non-exclusive mechanisms of virus transmission at cell-cell contacts have been proposed: (1) polarized budding of HTLV-1 into synaptic clefts; and (2) cell surface transfer of viral biofilms at virological synapses. In contrast to CD4⁺ T-cells, dendritic cells can be infected cell-free and, to a greater extent, via viral biofilms in vitro. Cell-to-cell transmission of HTLV-1 requires a coordinated action of steps in the virus infectious cycle with events in the cell-cell adhesion process; therefore, virus propagation from cell-to-cell depends on specific interactions between cellular and viral proteins. Here, we review the molecular mechanisms of HTLV-1 transmission with a focus on the HTLV-1-encoded proteins Tax and p8, their impact on host cell factors mediating cell-cell contacts, cytoskeletal remodeling, and thus, virus propagation. PMID:27005656

  4. Structure and cell biology of archaeal virus STIV.

    Science.gov (United States)

    Fu, Chi-yu; Johnson, Johnson E

    2012-04-01

    Recent investigations of archaeal viruses have revealed novel features of their structures and life cycles when compared to eukaryotic and bacterial viruses, yet there are structure-based unifying themes suggesting common ancestral relationships among dsDNA viruses in the three kingdoms of life. Sulfolobus solfataricus and the infecting virus Sulfolobus turreted icosahedral virus (STIV) is one of the well-established model systems to study archaeal virus replication and viral-host interactions. Reliable laboratory conditions to propagate STIV and available genetic tools allowed structural characterization of the virus and viral components that lead to the proposal of common capsid ancestry with PRD1 (bacteriophage), Adenovirus (eukaryotic virus) and PBCV (chlorellavirus). Microarray and proteomics approaches systematically analyzed viral replication and the corresponding host responses. Cellular cryo-electron tomography and thin-section EM studies uncovered the assembly and maturation pathway of STIV and revealed dramatic cellular ultra-structure changes upon infection. The viral-induced pyramid-like protrusions on cell surfaces represent a novel viral release mechanism and previously uncharacterized functions in viral replication. PMID:22482708

  5. Induction of apoptosis in frog virus 3-infected cells.

    Science.gov (United States)

    Chinchar, V G; Bryan, Locke; Wang, J; Long, Scott; Chinchar, G D

    2003-02-15

    The ability of frog virus 3 (FV3), the type species of the family Iridoviridae, to induce apoptosis was examined by monitoring DNA cleavage, chromatin condensation, and cell-surface expression of phosphotidylserine (PS) in fathead minnow (FHM) and baby hamster kidney (BHK) cells. In productively infected FHM cells, DNA fragmentation was first noted at 6-7 h postinfection and was clearly seen by 17 h postinfection, while chromatin condensation was detected at 8.5 h postinfection. As with some other viruses, FV3-induced apoptosis did not require de novo viral gene expression as both heat-inactivated and UV-inactivated virus readily triggered DNA fragmentation in FHM cells. Moreover, FV3-induced apoptosis was blocked in FHM cells by the pan-caspase inhibitor Z-VAD-FMK, suggesting that virus infection triggers programmed cell death through activation of the caspase cascade. FV3 infection also triggered apoptosis in BHK cells as monitored by TUNEL and annexin V binding assays. To determine whether FV3, similar to other large DNA viruses, encoded proteins that block or delay apoptosis, mock- and FV3-infected FHM cells were osmotically shocked and assayed for DNA fragmentation 3 hours later. DNA fragmentation was clearly seen whether or not shocked cells were previously infected with FV3, indicating that infection with FV3 did not block apoptosis induced by osmotic shock in FHM cells. The above results demonstrate that iridoviruses triggered apoptosis and that the induction of programmed cell death did not require viral gene expression. However, it remains to be determined if virion attachment to target cells is sufficient to induce cell death, or if apoptosis is triggered directly or indirectly by one or more virion-associated proteins. PMID:12642103

  6. Compatibility of lyotropic liquid crystals with viruses and mammalian cells that support the replication of viruses.

    Science.gov (United States)

    Cheng, Li-Lin; Luk, Yan-Yeung; Murphy, Christopher J; Israel, Barbara A; Abbott, Nicholas L

    2005-12-01

    We report a study that investigates the biocompatibility of materials that form lyotropic liquid crystals (LCs) with viruses and mammalian cells that support the replication of viruses. This study is focused on aqueous solutions of tetradecyldimethyl-amineoxide (C(14)AO) and decanol (D), or disodium cromoglycate (DSCG; C(23)H(14)O(11)Na(2)), which can form optically birefringent, liquid crystalline phases. The influence of these materials on the ability of vesicular stomatitis virus (VSV) to infect human epitheloid cervical carcinoma (HeLa) cells was examined by two approaches. First, VSV was dispersed in aqueous C(14)AO+ D or DSCG, and then HeLa cells were inoculated by contacting the cells with the aqueous C(14)AO + D or DSCG containing VSV. The infectivity of VSV to the HeLa cells was subsequently determined. Second, VSV was incubated in LC phases of either C(14)AO + D or DSCG for 4 h, and the concentration (titer) of infectious virus in the LC was determined by dilution into cell culture medium and subsequent inoculation of HeLa cells. Using these approaches, we found that the LC containing C(14)AO + D caused inactivation of virus as well as cell death. In contrast, we determined that VSV retained its infectivity in the presence of aqueous DSCG, and that greater than 74-82% of the HeLa cells survived contact with aqueous DSCG (depending on concentration of DSCG). Because VSV maintained its function (and we infer structure) in LCs formed from DSCG, we further explored the influence of the virus on the ordering of the LC. Whereas the LC formed from DSCG was uniformly aligned on surfaces prepared from self-assembled monolayers (SAMs) of HS(CH(2))(11)(OCH(2)CH(2))(4)OH on obliquely deposited films of gold in the absence of VSV, the introduction of 10(7)-10(8) infectious virus particles per milliliter caused the LC to assume a non-uniform orientation and a colorful appearance that was readily distinguished from the uniformly aligned LCs. Control experiments using

  7. Apoptosis in Raji cell line induced by influenza A virus

    Institute of Scientific and Technical Information of China (English)

    李虹; 肖丽英; 李华林; 李婉宜; 蒋中华; 张林; 李明远

    2003-01-01

    Objective To study the apoptotic effects of influenza A virus on the Raji cell line. Methods Cultured Raji cells were infected with influenza A virus at a multiplicity of infection (m.o.i) of 20 and the effects of apoptosis were detected at different time points post infection using the following methods: electron microscope, DNA agarose gel electrophoresis, PI stained flow cytometry (FCM) and Annexin-V FITC/PI stained FCM.Results Raji cells infected with influenza A virus showed changes of morphology apoptotis, DNA agarose electrophoresis also demonstrated a ladder-like pattern of DNA fragments in a time-dependent manner. PI stained FCM showed "apoptosis peak" and FITC/PI stained FCM showed apoptotic cells. Quantitative analysis indicated that the percentage of apoptotic Raji cells increased after infection, and cycloheximide (CHX), an eukaryotic transcription inhibitor, could effectively inhibit the apoptotic effects of influenza A virus in vitro.Conclusions Influenza A virus can induce apoptosis in Raji cell line suggesting that it may lead to a potential method for tumor therapy.

  8. Global Dynamics of a Virus Dynamical Model with Cell-to-Cell Transmission and Cure Rate

    Directory of Open Access Journals (Sweden)

    Tongqian Zhang

    2015-01-01

    Full Text Available The cure effect of a virus model with both cell-to-cell transmission and cell-to-virus transmission is studied. By the method of next generation matrix, the basic reproduction number is obtained. The locally asymptotic stability of the virus-free equilibrium and the endemic equilibrium is considered by investigating the characteristic equation of the model. The globally asymptotic stability of the virus-free equilibrium is proved by constructing suitable Lyapunov function, and the sufficient condition for the globally asymptotic stability of the endemic equilibrium is obtained by constructing suitable Lyapunov function and using LaSalle invariance principal.

  9. Infection of differentiated porcine airway epithelial cells by influenza virus: differential susceptibility to infection by porcine and avian viruses.

    Directory of Open Access Journals (Sweden)

    Darsaniya Punyadarsaniya

    Full Text Available BACKGROUND: Swine are important hosts for influenza A viruses playing a crucial role in the epidemiology and interspecies transmission of these viruses. Respiratory epithelial cells are the primary target cells for influenza viruses. METHODOLOGY/PRINCIPAL FINDINGS: To analyze the infection of porcine airway epithelial cells by influenza viruses, we established precision-cut lung slices as a culture system for differentiated respiratory epithelial cells. Both ciliated and mucus-producing cells were found to be susceptible to infection by swine influenza A virus (H3N2 subtype with high titers of infectious virus released into the supernatant already one day after infection. By comparison, growth of two avian influenza viruses (subtypes H9N2 and H7N7 was delayed by about 24 h. The two avian viruses differed both in the spectrum of susceptible cells and in the efficiency of replication. As the H9N2 virus grew to titers that were only tenfold lower than that of a porcine H3N2 virus this avian virus is an interesting candidate for interspecies transmission. Lectin staining indicated the presence of both α-2,3- and α-2,6-linked sialic acids on airway epithelial cells. However, their distribution did not correlate with pattern of virus infection indicating that staining by plant lectins is not a reliable indicator for the presence of cellular receptors for influenza viruses. CONCLUSIONS/SIGNIFICANCE: Differentiated respiratory epithelial cells significantly differ in their susceptibility to infection by avian influenza viruses. We expect that the newly described precision-cut lung slices from the swine lung are an interesting culture system to analyze the infection of differentiated respiratory epithelial cells by different pathogens (viral, bacterial and parasitic ones of swine.

  10. Biology of Zika virus infection in human skin cells

    OpenAIRE

    Hamel, Rodolphe; Dejarnac, Ophélie; Wichit, Sineewanlaya; Ekchariyawat, Peeraya; Neyret, Aymeric; Luplertlop, Natthanej; Perera-Lecoin, Manuel; Surasombatpattana, Pornapat; Talignani, Loïc; Thomas, Frédéric; Cao-Lormeau, Van-Mai; Choumet, Valérie; Briant, Laurence; Desprès, Philippe; Amara, Ali

    2015-01-01

    Zika virus (ZIKV) is an emerging arbovirus of the Flaviviridae family, which includes dengue, West Nile, yellow fever, and Japanese encephalitis viruses, that causes a mosquito-borne disease transmitted by the Aedes genus, with recent outbreaks in the South Pacific. Here we examine the importance of human skin in the entry of ZIKV and its contribution to the induction of antiviral immune responses. We show that human dermal fibroblasts, epidermal keratinocytes, and immature dendritic cells ar...

  11. Simian Immunodeficiency Virus Interactions with Macaque Dendritic Cells

    OpenAIRE

    Teleshova, Natalia; Derby, Nina; Martinelli, Elena; Pugach, Pavel; Calenda, Giulia; Robbiani, Melissa

    2013-01-01

    This chapter summarizes advances in the following areas: (1) dendritic cell (DC)-mediated simian immunodeficiency virus (SIV) transmission, (2) role of DCs in innate and adaptive immunity against SIV, and (3) approaches to harness DC function to induce anti-SIV responses. The nonhuman primate (NHP) model of human immunodeficiency virus (HIV) infection in rhesus macaques and other Asian NHP species is highly relevant to advance the understanding of virus–host interactions critical for transmis...

  12. Conservation of T cell epitopes between seasonal inlfuenza viruses and the novel inlfuenza A H7N9 virus

    Institute of Scientific and Technical Information of China (English)

    Huawei Mao; Hui-Ling Yen; Yinping Liu; Yu-Lung Lau; JS Malik Peiris; Wenwei Tu

    2014-01-01

    A novel avian influenza A (H7N9) virus recently emerged in the Yangtze River delta and caused diseases, often severe, in over 130 people. This H7N9 virus appeared to infect humans with greater ease than previous avian inlfuenza virus subtypes such as H5N1 and H9N2. While there are other potential explanations for this large number of human infections with an avian influenza virus, we investigated whether a lack of conserved T-cell epitopes between endemic H1N1 and H3N2 inlfuenza viruses and the novel H7N9 virus contributes to this observation. Here we demonstrate that a number of T cell epitopes are conserved between endemic H1N1 and H3N2 viruses and H7N9 virus. Most of these conserved epitopes are from viral internal proteins. The extent of conservation between endemic human seasonal inlfuenza and avian inlfuenza H7N9 was comparable to that with the highly pathogenic avian inlfuenza H5N1. Thus, the ease of inter-species transmission of H7N9 viruses (compared with avian H5N1 viruses) cannot be attributed to the lack of conservation of such T cell epitopes. On the contrary, our ifndings predict signiifcant T-cell based cross-reactions in the human population to the novel H7N9 virus. Our findings also have implications for H7N9 virus vaccine design.

  13. A novel single virus infection system reveals that influenza virus preferentially infects cells in g1 phase.

    Directory of Open Access Journals (Sweden)

    Ryuta Ueda

    Full Text Available BACKGROUND: Influenza virus attaches to sialic acid residues on the surface of host cells via the hemagglutinin (HA, a glycoprotein expressed on the viral envelope, and enters into the cytoplasm by receptor-mediated endocytosis. The viral genome is released and transported in to the nucleus, where transcription and replication take place. However, cellular factors affecting the influenza virus infection such as the cell cycle remain uncharacterized. METHODS/RESULTS: To resolve the influence of cell cycle on influenza virus infection, we performed a single-virus infection analysis using optical tweezers. Using this newly developed single-virus infection system, the fluorescence-labeled influenza virus was trapped on a microchip using a laser (1064 nm at 0.6 W, transported, and released onto individual H292 human lung epithelial cells. Interestingly, the influenza virus attached selectively to cells in the G1-phase. To clarify the molecular differences between cells in G1- and S/G2/M-phase, we performed several physical and chemical assays. Results indicated that: 1 the membranes of cells in G1-phase contained greater amounts of sialic acids (glycoproteins than the membranes of cells in S/G2/M-phase; 2 the membrane stiffness of cells in S/G2/M-phase is more rigid than those in G1-phase by measurement using optical tweezers; and 3 S/G2/M-phase cells contained higher content of Gb3, Gb4 and GlcCer than G1-phase cells by an assay for lipid composition. CONCLUSIONS: A novel single-virus infection system was developed to characterize the difference in influenza virus susceptibility between G1- and S/G2/M-phase cells. Differences in virus binding specificity were associated with alterations in the lipid composition, sialic acid content, and membrane stiffness. This single-virus infection system will be useful for studying the infection mechanisms of other viruses.

  14. Cell Transformation by RNA Viruses: An Overview

    OpenAIRE

    Hung Fan

    2011-01-01

    Studies of oncogenic viruses have made seminal contributions to the molecular biology of cancer. Key discoveries include the identification of viral oncogenes and cellular proto-oncogenes, elucidation of signal transduction pathways, and identification of tumor suppressor genes. The origins of cancer virology began almost exactly one hundred years ago with the discovery of avian sarcoma and acute leukemia viruses—RNA-containing viruses of the retrovirus family. The study of animal cancer viru...

  15. Protective Cytotoxic T-Cell Responses Induced by Venezuelan Equine Encephalitis Virus Replicons Expressing Ebola Virus Proteins

    OpenAIRE

    Olinger, Gene G.; Bailey, Michael A.; Dye, John M.; Bakken, Russell; Kuehne, Ana; Kondig, John; Wilson, Julie; Hogan, Robert J.; Hart, Mary Kate

    2005-01-01

    Infection with Ebola virus causes a severe disease accompanied by high mortality rates, and there are no licensed vaccines or therapies available for human use. Filovirus vaccine research efforts still need to determine the roles of humoral and cell-mediated immune responses in protection from Ebola virus infection. Previous studies indicated that exposure to Ebola virus proteins expressed from packaged Venezuelan equine encephalitis virus replicons elicited protective immunity in mice and th...

  16. Hepatitis C virus cell-cell transmission and resistance to direct-acting antiviral agents

    DEFF Research Database (Denmark)

    Xiao, Fei; Fofana, Isabel; Heydmann, Laura;

    2014-01-01

    -targeting entry inhibitors (HTEIs) was highly effective in inhibiting viral dissemination of resistant genotype 2 viruses. Combining HTEIs with DAAs prevented antiviral resistance and led to rapid elimination of the virus in cell culture model. In conclusion, our work provides evidence that cell-cell transmission......Hepatitis C virus (HCV) is transmitted between hepatocytes via classical cell entry but also uses direct cell-cell transfer to infect neighboring hepatocytes. Viral cell-cell transmission has been shown to play an important role in viral persistence allowing evasion from neutralizing antibodies. In...... contrast, the role of HCV cell-cell transmission for antiviral resistance is unknown. Aiming to address this question we investigated the phenotype of HCV strains exhibiting resistance to direct-acting antivirals (DAAs) in state-of-the-art model systems for cell-cell transmission and spread. Using HCV...

  17. Ceramics adsorbing virus and cells. Uirusu, saibo bunri ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Hiraide, T. (Asahi Optical Co. Ltd., Tokyo (Japan))

    1993-07-01

    It has been reported that hydroxyapatite (HA), which is the main inorganic component of teeth and bones of homo sapiens and used for biomaterials such as artificial tooth roots, adsorbs viruses such as influenza viruses. In this article, the history of development up to now of HA and its adsorption mechanism of protein, virus, etc., are introduced. HA was applied for chromatography in 1956 becoming one of the separating and refining methods of protein and nucleic acid, then after the development of spherical porous HA, it has become applied for high speed liquid chromatography (HPLC). Also by means of a column filled with HA granules, T-cells have been able to be purified in a short time from lymphocyte which was separated from the blood of homo sapiens. Recently it has also been reported that HA granules can adsorb influenza viruses, Japanese encephalitis viruses, polio viruses and hepatitis B viruses, and a cold-preventative mask based upon this report is now on sale. 11 refs., 7 figs.

  18. Proteome analysis of virus-host cell interaction: rabies virus replication in Vero cells in two different media.

    Science.gov (United States)

    Kluge, Sabine; Rourou, Samia; Vester, Diana; Majoul, Samy; Benndorf, Dirk; Genzel, Yvonne; Rapp, Erdmann; Kallel, Héla; Reichl, Udo

    2013-06-01

    The use of Vero cells for rabies vaccine production was recommended from the WHO in 2005. A controlled production process is necessary to reduce the risk of contaminants in the product. One step towards this is to turn away from animal-derived components (e.g. serum, trypsin, bovine serum albumin) and face a production process in animal component-free medium. In this study, a proteomic approach was applied, using 2-D differential gel electrophoresis and mass spectrometry to compare rabies virus propagation in Vero cells under different cultivation conditions in microcarrier culture. Protein alterations were investigated for uninfected and infected Vero cells over a time span from 1 to 8 days post-infection in two different types of media (serum-free versus serum-containing media). For mock-infected cells, proteins involved in stress response, redox status, protease activity or glycolysis, and protein components in the endoplasmic reticulum were found to be differentially expressed comparing both cultivation media at all sampling points. For virus-infected cells, additionally changes in protein expression involved in general cell regulation and in calcium homeostasis were identified under both cultivation conditions. The fact that neither of these additional proteins was identified for cells during mock infection, but similar protein expression changes were found for both systems during virus propagation, indicates for a specific response of the Vero cell proteome on rabies virus infection. PMID:23674149

  19. Rabies virus-like particles expressed in HEK293 cells.

    Science.gov (United States)

    Fontana, Diego; Kratje, Ricardo; Etcheverrigaray, Marina; Prieto, Claudio

    2014-05-19

    Rabies is an infectious viral disease with a mortality rate close to 100%. Currently, there is a need to generate cheaper and more immunogenic vaccines for the effective prevention of rabies, mostly in developing countries. Virus-like particles have been widely used in viral vaccine production due to their high immunogenicity and safety during the production process. Rabies virus glycoprotein is the major antigen to trigger a protective immune response and the only protein capable of generating virus neutralizing antibodies. In this study we describe the development of a recombinant stable cell line for the production of rabies virus-like particles (RV-VLPs) expressing the rabies virus glycoprotein by lentivirus-based transduction of HEK293 cells. Protein expression was analyzed by flow cytometry, fluorescence microscopy, western blot and ELISA. Particles were purified from culture supernatant and their size and morphology were studied. Furthermore, mice were immunized with RV-VLPs, formulated with adjuvant, and these particles were able to produce a specific antibody response, demonstrating that these virus-like particles present a promising rabies vaccine candidate. PMID:24631077

  20. Gamma interferon augments Fc gamma receptor-mediated dengue virus infection of human monocytic cells.

    OpenAIRE

    Kontny, U; Kurane, I; Ennis, F A

    1988-01-01

    It has been reported that anti-dengue antibodies at subneutralizing concentrations augment dengue virus infection of monocytic cells. This is due to the increased uptake of dengue virus in the form of virus-antibody complexes by cells via Fc gamma receptors. We analyzed the effects of recombinant human gamma interferon (rIFN-gamma) on dengue virus infection of human monocytic cells. U937 cells, a human monocytic cell line, were infected with dengue virus in the form of virus-antibody complexe...

  1. Differential sensitivity of bat cells to infection by enveloped RNA viruses: coronaviruses, paramyxoviruses, filoviruses, and influenza viruses.

    Directory of Open Access Journals (Sweden)

    Markus Hoffmann

    Full Text Available Bats (Chiroptera host major human pathogenic viruses including corona-, paramyxo, rhabdo- and filoviruses. We analyzed six different cell lines from either Yinpterochiroptera (including African flying foxes and a rhinolophid bat or Yangochiroptera (genera Carollia and Tadarida for susceptibility to infection by different enveloped RNA viruses. None of the cells were sensitive to infection by transmissible gastroenteritis virus (TGEV, a porcine coronavirus, or to infection mediated by the Spike (S protein of SARS-coronavirus (SARS-CoV incorporated into pseudotypes based on vesicular stomatitis virus (VSV. The resistance to infection was overcome if cells were transfected to express the respective cellular receptor, porcine aminopeptidase N for TGEV or angiotensin-converting enzyme 2 for SARS-CoV. VSV pseudotypes containing the S proteins of two bat SARS-related CoV (Bg08 and Rp3 were unable to infect any of the six tested bat cell lines. By contrast, viral pseudotypes containing the surface protein GP of Marburg virus from the family Filoviridae infected all six cell lines though at different efficiency. Notably, all cells were sensitive to infection by two paramyxoviruses (Sendai virus and bovine respiratory syncytial virus and three influenza viruses from different subtypes. These results indicate that bat cells are more resistant to infection by coronaviruses than to infection by paramyxoviruses, filoviruses and influenza viruses. Furthermore, these results show a receptor-dependent restriction of the infection of bat cells by CoV. The implications for the isolation of coronaviruses from bats are discussed.

  2. CD4+ T cell responses in hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    Nasser Semmo; Paul Klenerman

    2007-01-01

    Hepatitis C virus (HCV) infection is a major cause of liver damage, with virus-induced end-stage disease such as liver cirrhosis and hepatocellular carcinoma resulting in a high rate of morbidity and mortality worldwide. Evidence that CD4+ T cell responses to HCV play an important role in the outcome of acute infection has been shown in several studies. However, the mechanisms behind viral persistence and the failure of CD4+ T cell responses to contain virus are poorly understood. During chronic HCV infection, HCV-specific CD4+ T cell responses are relatively weak or absent whereas in resolved infection these responses are vigorous and multispecific. Persons with a T-helper type Ⅰ profile, which promotes cellular effector mechanisms are thought to be more likely to experience viral clearance, but the overall role of these cells in the immunopathogenesis of chronic liver disease is not known. To define this, much more data is required on the function and specificity of virus-specific CD4+ T cells,especially in the early phases of acute disease and in the liver during chronic infection. The role and possible mechanisms of action of CD4+ T cell responses in determining the outcome of acute and chronic HCV infection will be discussed in this review.

  3. The Arabidopsis synaptotagmin SYTA regulates the cell-to-cell movement of diverse plant viruses

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    Asako eUchiyama

    2014-11-01

    Full Text Available Synaptotagmins are a large gene family in animals that have been extensively characterized due to their role as calcium sensors to regulate synaptic vesicle exocytosis and endocytosis in neurons, and dense core vesicle exocytosis for hormone secretion from neuroendocrine cells. Thought to be exclusive to animals, synaptotagmins have recently been characterized in Arabidopsis thaliana, in which they comprise a five gene family. Using infectivity and leaf-based functional assays, we have shown that Arabidopsis SYTA regulates endocytosis and marks an endosomal vesicle recycling pathway to regulate movement protein-mediated trafficking of the Begomovirus Cabbage leaf curl virus (CaLCuV and the Tobamovirus Tobacco mosaic virus (TMV through plasmodesmata (Lewis and Lazarowitz, 2010. To determine whether SYTA has a central role in regulating the cell-to-cell trafficking of a wider range of diverse plant viruses, we extended our studies here to examine the role of SYTA in the cell-to-cell movement of additional plant viruses that employ different modes of movement, namely the Potyvirus Turnip mosaic virus (TuMV, the Caulimovirus Cauliflower mosaic virus (CaMV and the Tobamovirus Turnip vein clearing virus (TVCV, which in contrast to TMV does efficiently infect Arabidopsis. We found that both TuMV and TVCV systemic infection, and the cell-to-cell trafficking of the their movement proteins, were delayed in the Arabidopsis Col-0 syta-1 knockdown mutant. In contrast, CaMV systemic infection was not inhibited in syta-1. Our studies show that SYTA is a key regulator of plant virus intercellular movement, being necessary for the ability of diverse cell-to-cell movement proteins encoded by Begomoviruses (CaLCuV MP, Tobamoviruses (TVCV and TMV 30K protein and Potyviruses (TuMV P3N-PIPO to alter PD and thereby mediate virus cell-to-cell spread.

  4. The cell biology of Tobacco mosaic virus replication and movement

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    Chengke eLiu

    2013-02-01

    Full Text Available Successful systemic infection of a plant by Tobacco mosaic virus (TMV requires three processes that repeat over time: initial establishment and accumulation in invaded cells, intercellular movement and systemic transport. Accumulation and intercellular movement of TMV necessarily involves intracellular transport by complexes containing virus and host proteins and virus RNA during a dynamic process that can be visualized. Multiple membranes appear to assist TMV accumulation, while membranes, microfilaments and microtubules appear to assist TMV movement. Here we review cell biological studies that describe TMV-membrane, -cytoskeleton and -other host protein interactions which influence virus accumulation and movement in leaves and callus tissue. The importance of understanding the developmental phase of the infection in relationship to the observed virus-membrane or -host protein interaction is emphasized. Utilizing the latest observations of TMV-membrane and -host protein interactions within our evolving understanding of the infection ontogeny, a model for TMV accumulation and intracellular spread in a cell biological context is provided.

  5. Epidemic of AIDS related virus (HTLV-III/LAV) infection among intravenous drug abusers.

    Science.gov (United States)

    Robertson, J R; Bucknall, A B; Welsby, P D; Roberts, J J; Inglis, J M; Peutherer, J F; Brettle, R P

    1986-02-22

    Stored blood samples from 164 intravenous drug abusers who attended a Scottish general practice were tested for HTLV-III/LAV (human T cell lymphotropic virus type III/lymphadenopathy associated virus) infection. Of those tested, 83 (51%) were seropositive, which is well above the prevalence reported elsewhere in Britain and Europe and approaches that observed in New York City. The timing of taking samples of negative sera and continued drug use suggest that as many as 85% of this population might now be infected. The infection became epidemic in late 1983 and early 1984, thereafter becoming endemic. The practice of sharing needles and syringes correlated with seropositivity, which, combined with the almost exclusive intravenous use of heroin and other behavioural patterns, may explain the high prevalence of HTLV-III/LAV infection in the area. Rapid and aggressive intervention is needed to control the spread of infection. PMID:3081158

  6. Adult T-cell lymphoma/leukemia presenting as isolated central nervous system T-cell lymphoma.

    Science.gov (United States)

    Ma, Wei-Li; Li, Chi-Cheng; Yu, Shan-Chi; Tien, Hwei-Fang

    2014-01-01

    Adult T-cell leukemia/lymphoma (ATLL) is a T-cell neoplasm, associated with infection by the retrovirus human T-lymphotropic virus type 1 (HTLV-1). Central nervous system (CNS) involved by ATLL is often occurred in advanced disease, such as acute and lymphomatous variants. On the other hand, isolated CNS lymphoma is rare. We repot a 50-year-old woman who presented with multiple infiltrative brain lesions on the magnetic resonance (MR) imaging. Results of initial biopsy of brain tumor indicated CNS vasculitis. The patient received one course of high-dose methotrexate and MR imaging of brain revealed remission of infiltrative lesions. Two years later, new brain lesions were detected. Histopathologic examination of specimens via craniotomy revealed T-cell lymphoma. The patient responded poorly to subsequent chemotherapy, and salvage whole-brain irradiation was performed. Six months later, the patient had hepatosplenomegaly, hypercalcemia, and multiple lymphocytes with a cloverleaf appearance in circulation. Results of flow cytometry analysis of peripheral blood indicated ATLL and antibodies to human T-lymphotropic virus type 1 (HTLV-1) were detected. Clinicians should screen HTLV-1 infection when patients are diagnosed with peripheral T-cell lymphoma. Combined antiviral therapy and intensive chemotherapy may improve the outcomes of ATLL. PMID:25587470

  7. Adult T-Cell Lymphoma/Leukemia Presenting as Isolated Central Nervous System T-Cell Lymphoma

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    Wei-Li Ma

    2014-01-01

    Full Text Available Adult T-cell leukemia/lymphoma (ATLL is a T-cell neoplasm, associated with infection by the retrovirus human T-lymphotropic virus type 1 (HTLV-1. Central nervous system (CNS involved by ATLL is often occurred in advanced disease, such as acute and lymphomatous variants. On the other hand, isolated CNS lymphoma is rare. We repot a 50-year-old woman who presented with multiple infiltrative brain lesions on the magnetic resonance (MR imaging. Results of initial biopsy of brain tumor indicated CNS vasculitis. The patient received one course of high-dose methotrexate and MR imaging of brain revealed remission of infiltrative lesions. Two years later, new brain lesions were detected. Histopathologic examination of specimens via craniotomy revealed T-cell lymphoma. The patient responded poorly to subsequent chemotherapy, and salvage whole-brain irradiation was performed. Six months later, the patient had hepatosplenomegaly, hypercalcemia, and multiple lymphocytes with a cloverleaf appearance in circulation. Results of flow cytometry analysis of peripheral blood indicated ATLL and antibodies to human T-lymphotropic virus type 1 (HTLV-1 were detected. Clinicians should screen HTLV-1 infection when patients are diagnosed with peripheral T-cell lymphoma. Combined antiviral therapy and intensive chemotherapy may improve the outcomes of ATLL.

  8. Identification of chikungunya virus interacting proteins in mammalian cells

    Indian Academy of Sciences (India)

    Mandar S Paingankar; Vidya A Arankalle

    2014-06-01

    Identification and characterization of virus host interactions is an essential step for the development of novel antiviral strategies. Very few studies have been targeted towards identification of chikungunya virus (CHIKV) interacting host proteins. In current study, virus overlay protein binding assay (VOPBA) and matrix-assisted laser desorption/ionization time of flight analysis (MALDI TOF/TOF) were employed for the identification of CHIKV binding proteins in mammalian cells. HSP70 and actin were identified as virus binding proteins in HEK-293T and Vero-E6 cells, whereas STAT-2 was identified as an additional protein in Vero-E6 cells. Pre-incubation with anti-HSP70 antibody and miRNA silencing of HSP70 significantly reduced the CHIKV production in HEK-293T and Vero-E6 cells at early time points. These results suggest that CHIKV exploits the housekeeping molecules such as actin, HSP70 and STAT-2 to establish infection in the mammalian cells.

  9. Variation in RNA virus mutation rates across host cells.

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    Marine Combe

    2014-01-01

    Full Text Available It is well established that RNA viruses exhibit higher rates of spontaneous mutation than DNA viruses and microorganisms. However, their mutation rates vary amply, from 10(-6 to 10(-4 substitutions per nucleotide per round of copying (s/n/r and the causes of this variability remain poorly understood. In addition to differences in intrinsic fidelity or error correction capability, viral mutation rates may be dependent on host factors. Here, we assessed the effect of the cellular environment on the rate of spontaneous mutation of the vesicular stomatitis virus (VSV, which has a broad host range and cell tropism. Luria-Delbrück fluctuation tests and sequencing showed that VSV mutated similarly in baby hamster kidney, murine embryonic fibroblasts, colon cancer, and neuroblastoma cells (approx. 10(-5 s/n/r. Cell immortalization through p53 inactivation and oxygen levels (1-21% did not have a significant impact on viral replication fidelity. This shows that previously published mutation rates can be considered reliable despite being based on a narrow and artificial set of laboratory conditions. Interestingly, we also found that VSV mutated approximately four times more slowly in various insect cells compared with mammalian cells. This may contribute to explaining the relatively slow evolution of VSV and other arthropod-borne viruses in nature.

  10. THE STUDY OF VIRUSES REPRODUCTION IN CELL CULTURES BY THE METHOD OF MATHEMATICAL MODELING

    OpenAIRE

    N. A. Kontarov; S. A. Grishunina; N. V. Balaev; N. V. Yuminova; V. V. Zverev

    2014-01-01

    Abstract. In the study the mathematical analysis of viruses reproduction in cell culture using the Marchuk’ mathematical model to predict  reproduction of virus in one or another cell cultures has been conducted. The obtained theoretical results are corresponded to the experimental data on reproduction of rubella virus in cell cultures RK-13 and BHK-21. The sum of theoretical and experimental results can be used to select the optimal cell cultures for virus cumulation.

  11. Toso regulates differentiation and activation of inflammatory dendritic cells during persistence-prone virus infection

    OpenAIRE

    Lang, P A; Meryk, A; Pandyra, A A; Brenner, D; A. Brüstle; Xu, H. C.; Merches, K; Lang, F; Khairnar, V; Sharma, P; Funkner, P; Recher, M.; Shaabani, N.; Duncan, G S; Duhan, V

    2014-01-01

    During virus infection and autoimmune disease, inflammatory dendritic cells (iDCs) differentiate from blood monocytes and infiltrate infected tissue. Following acute infection with hepatotropic viruses, iDCs are essential for re-stimulating virus-specific CD8+ T cells and therefore contribute to virus control. Here we used the lymphocytic choriomeningitis virus (LCMV) model system to identify novel signals, which influence the recruitment and activation of iDCs in the liver. We observed that ...

  12. Photodynamic inactivation of rubella virus enhances recombination with a latent virus of a baby hamster kidney cell line BHK21

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Nobuto; Urade, Masahiro (Hahnemann Univ. School of Medicine, Philadelphia, PA (USA))

    1989-09-01

    Rubella virus is very sensitive to photodynamic action. When tested with 1.2 x 10{sup -5} M toluidine blue and 8 W fluorescent lamp at a fluence of 11 W/m{sup 2}, inactivation kinetics showed a linear single hit curve with a k value of 1.48 min{sup -1}. Photodynamic inactivation of rubella virus greatly enhanced recombination with a latent virus (R-virus) of baby hamster kidney BHK21 cells. In contrast, no hybrids were detected in lysates of the cells infected with either UV-treated or untreated rubella virus. Therefore, hybrid viruses were readily detected only in lysates of BHK21 cells infected with photodynamically treated rubella virus. Photodynamic damage of rubella virus genomes generated a new hybrid type (hybrid type 3) in addition to a previously described type 2 hybrid (formerly designated as HPV-RV variant). Although both of these hybrid types carry the CF antigens of rubella virus, plaque forming ability of type 3 hybrid is neutralized neither by anti-rubella serum nor by anti-latent virus serum while type 2 hybrid is neutralized by anti-latent virus serum. (author).

  13. Effects of human respiratory syncytial virus, metapneumovirus, parainfluenza virus 3 and influenza virus on CD4+ T cell activation by dendritic cells.

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    Cyril Le Nouën

    Full Text Available BACKGROUND: Human respiratory syncytial virus (HRSV, and to a lesser extent human metapneumovirus (HMPV and human parainfluenza virus type 3 (HPIV3, re-infect symptomatically throughout life without antigenic change, suggestive of incomplete immunity. One causative factor is thought to be viral interference with dendritic cell (DC-mediated stimulation of CD4+ T cells. METHODOLOGY, PRINCIPAL FINDINGS: We infected human monocyte-derived DC with purified HRSV, HMPV, HPIV3, or influenza A virus (IAV and compared their ability to induce activation and proliferation of autologous CD4+ T cells in vitro. IAV was included because symptomatic re-infection without antigenic change is less frequent, suggesting that immune protection is more complete and durable. We examined virus-specific memory responses and superantigen-induced responses by multiparameter flow cytometry. Live virus was more stimulatory than inactivated virus in inducing DC-mediated proliferation of virus-specific memory CD4+ T cells, suggesting a lack of strong suppression by live virus. There were trends of increasing proliferation in the order: HMPVcells in response to IAV, but differences were not significant. Exposure of DC to HRSV, HPIV3, or IAV reduced CD4+ T cell proliferation in response to secondary stimulus with superantigen, but the effect was transitory and greatest for IAV. T cell cytokine production was similar, with no evidence of Th2 or Th17 skewing. CONCLUSIONS, SIGNIFICANCE: Understanding the basis for the ability of HRSV in particular to symptomatically re-infect without significant antigenic change is of considerable interest. The present results show that these common respiratory viruses are similar in their ability to induce DC to activate CD4+ T cells. Thus, the results do not support the common model in which viral suppression of CD4+ T cell activation and

  14. Infectivity of wild-type rubella virus in fibrochondrocyte cells

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    Cristina A Figueiredo

    2004-02-01

    Full Text Available This study describes the rapid growth of the rubella virus in samples of a primary fibrochondrocyte cell culture with the development of a cytopathic effect (CPE, in response to infection by the rubella virus. The cells were isolated from the meniscus joint of a rabbit after enzymatic extraction and incubated at 37°C with a Dulbecco's modified Eagle's medium (DMEM, supplemented with 10% fetal calf serum. A total of six clinical samples from urine, blood and cerebrospinal fluid were inoculated in the fibrochondrocyte and the cell lines of the African green monkey kidney - ATCC CCL-81 (Vero. The fibrochondrocyte cell showed CPE after 24 hours and virus growth was confirmed by immunohistochemistry and Nested PCR. The cells inoculated with samples were examined by phase contrast microscopy and showed characteristic rounding, along with bipolar and multipolar cells. The infection curve increased during the five days of observation, showing that the titers in fibrochondrocyte cells were then higher than those observed in Vero cell lines.

  15. Tracking virus-specific CD4+ T cells during and after acute hepatitis C virus infection.

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    Michaela Lucas

    Full Text Available BACKGROUND: CD4+ T cell help is critical in maintaining antiviral immune responses and such help has been shown to be sustained in acute resolving hepatitis C. In contrast, in evolving chronic hepatitis C CD4+ T cell helper responses appear to be absent or short-lived, using functional assays. METHODOLOGY/PRINCIPAL FINDINGS: Here we used a novel HLA-DR1 tetramer containing a highly targeted CD4+ T cell epitope from the hepatitis C virus non-structural protein 4 to track number and phenotype of hepatitis C virus specific CD4+ T cells in a cohort of seven HLA-DR1 positive patients with acute hepatitis C in comparison to patients with chronic or resolved hepatitis C. We observed peptide-specific T cells in all seven patients with acute hepatitis C regardless of outcome at frequencies up to 0.65% of CD4+ T cells. Among patients who transiently controlled virus replication we observed loss of function, and/or physical deletion of tetramer+ CD4+ T cells before viral recrudescence. In some patients with chronic hepatitis C very low numbers of tetramer+ cells were detectable in peripheral blood, compared to robust responses detected in spontaneous resolvers. Importantly we did not observe escape mutations in this key CD4+ T cell epitope in patients with evolving chronic hepatitis C. CONCLUSIONS/SIGNIFICANCE: During acute hepatitis C a CD4+ T cell response against this epitope is readily induced in most, if not all, HLA-DR1+ patients. This antiviral T cell population becomes functionally impaired or is deleted early in the course of disease in those where viremia persists.

  16. Nipah virus infection and glycoprotein targeting in endothelial cells

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    Maisner Andrea

    2010-11-01

    Full Text Available Abstract Background The highly pathogenic Nipah virus (NiV causes fatal respiratory and brain infections in animals and humans. The major hallmark of the infection is a systemic endothelial infection, predominantly in the CNS. Infection of brain endothelial cells allows the virus to overcome the blood-brain-barrier (BBB and to subsequently infect the brain parenchyma. However, the mechanisms of NiV replication in endothelial cells are poorly elucidated. We have shown recently that the bipolar or basolateral expression of the NiV surface glycoproteins F and G in polarized epithelial cell layers is involved in lateral virus spread via cell-to-cell fusion and that correct sorting depends on tyrosine-dependent targeting signals in the cytoplasmic tails of the glycoproteins. Since endothelial cells share many characteristics with epithelial cells in terms of polarization and protein sorting, we wanted to elucidate the role of the NiV glycoprotein targeting signals in endothelial cells. Results As observed in vivo, NiV infection of endothelial cells induced syncytia formation. The further finding that infection increased the transendothelial permeability supports the idea of spread of infection via cell-to-cell fusion and endothelial cell damage as a mechanism to overcome the BBB. We then revealed that both glycoproteins are expressed at lateral cell junctions (bipolar, not only in NiV-infected primary endothelial cells but also upon stable expression in immortalized endothelial cells. Interestingly, mutation of tyrosines 525 and 542/543 in the cytoplasmic tail of the F protein led to an apical redistribution of the protein in endothelial cells whereas tyrosine mutations in the G protein had no effect at all. This fully contrasts the previous results in epithelial cells where tyrosine 525 in the F, and tyrosines 28/29 in the G protein were required for correct targeting. Conclusion We conclude that the NiV glycoprotein distribution is responsible for

  17. INFECTIVITY AND PERSISTENCE OF VESICULAR STOMATITIS VIRUS IN CULICOIDES CELLS

    Science.gov (United States)

    The biting midge, Culicoides sonorensis, was recently shown to be a biologically competent vector for the arbovirus, vesicular stomatitis virus (VSV). While arboviruses can be extremely pathogenic to mammalian cells, they typically do not exert deleterious effects on their insect vectors. Infectio...

  18. Regulatory T Cells in Chronic Hepatitis B Virus Infection

    NARCIS (Netherlands)

    J.N. Stoop (Jeroen Nicolaas)

    2007-01-01

    textabstractWorldwide 400 million people suffer from chronic hepatitis B virus (HBV) infection and approximately 1 million people die annually from HBV-related disease. To clear HBV, an effective immune response, in which several cell types and cytokines play a role, is important. It is known that p

  19. Newly described human polyomaviruses Merkel Cell, KI and WU are present in urban sewage and may represent potential environmental contaminants

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    Carratala Anna

    2010-06-01

    Full Text Available Abstract Recently, three new polyomaviruses (KI, WU and Merkel cell polyomavirus have been reported to infect humans. It has also been suggested that lymphotropic polyomavirus, a virus of simian origin, infects humans. KI and WU polyomaviruses have been detected mainly in specimens from the respiratory tract while Merkel cell polyomavirus has been described in a very high percentage of Merkel cell carcinomas. The distribution, excretion level and transmission routes of these viruses remain unknown. Here we analyzed the presence and characteristics of newly described human polyomaviruses in urban sewage and river water in order to assess the excretion level and the potential role of water as a route of transmission of these viruses. Nested-PCR assays were designed for the sensitive detection of the viruses studied and the amplicons obtained were confirmed by sequencing analysis. The viruses were concentrated following a methodology previously developed for the detection of JC and BK human polyomaviruses in environmental samples. JC polyomavirus and human adenoviruses were used as markers of human contamination in the samples. Merkel cell polyomavirus was detected in 7/8 urban sewage samples collected and in 2/7 river water samples. Also one urine sample from a pregnant woman, out of 4 samples analyzed, was positive for this virus. KI and WU polyomaviruses were identified in 1/8 and 2/8 sewage samples respectively. The viral strains detected were highly homologous with other strains reported from several other geographical areas. Lymphotropic polyomavirus was not detected in any of the 13 sewage neither in 9 biosolid/sludge samples analyzed. This is the first description of a virus isolated from sewage and river water with a strong association with cancer. Our data indicate that the Merkel cell polyomavirus is prevalent in the population and that it may be disseminated through the fecal/urine contamination of water. The procedure developed may

  20. Induction of cell-cell fusion by ectromelia virus is not inhibited by its fusion inhibitory complex

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    Fuchs Pinhas

    2009-09-01

    Full Text Available Abstract Background Ectromelia virus, a member of the Orthopox genus, is the causative agent of the highly infectious mousepox disease. Previous studies have shown that different poxviruses induce cell-cell fusion which is manifested by the formation of multinucleated-giant cells (polykaryocytes. This phenomenon has been widely studied with vaccinia virus in conditions which require artificial acidification of the medium. Results We show that Ectromelia virus induces cell-cell fusion under neutral pH conditions and requires the presence of a sufficient amount of viral particles on the plasma membrane of infected cells. This could be achieved by infection with a replicating virus and its propagation in infected cells (fusion "from within" or by infection with a high amount of virus particles per cell (fusion "from without". Inhibition of virus maturation or inhibition of virus transport on microtubules towards the plasma membrane resulted in a complete inhibition of syncytia formation. We show that in contrast to vaccinia virus, Ectromelia virus induces cell-cell fusion irrespectively of its hemagglutination properties and cell-surface expression of the orthologs of the fusion inhibitory complex, A56 and K2. Additionally, cell-cell fusion was also detected in mice lungs following lethal respiratory infection. Conclusion Ectromelia virus induces spontaneous cell-cell fusion in-vitro and in-vivo although expressing an A56/K2 fusion inhibitory complex. This syncytia formation property cannot be attributed to the 37 amino acid deletion in ECTV A56.

  1. The role of human T cell lymphotrophic virus type 1, hepatitis B virus and hepatitis C virus coinfections in leprosy

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    Paulo Roberto Lima Machado

    2012-12-01

    Full Text Available Leprosy spectrum and outcome is associated with the host immune response against Mycobacterium leprae. The role of coinfections in leprosy patients may be related to a depression of cellular immunity or amplification of inflammatory responses. Leprosy remains endemic in several regions where human T cell lymphotrophic virus type 1 (HTLV-1, hepatitis B virus (HBV or hepatitis C virus (HCV are also endemic. We have evaluated the evidence for the possible role of these viruses in the clinical manifestations and outcomes of leprosy. HTLV-1, HBV and HCV are associated with leprosy in some regions and institutionalization is an important risk factor for these viral coinfections. Some studies show a higher prevalence of viral coinfection in lepromatous cases. Although HBV and HCV coinfection were associated with reversal reaction in one study, there is a lack of information about the consequences of viral coinfections in leprosy. It is not known whether clinical outcomes associated with leprosy, such as development of reactions or relapses could be attributed to a specific viral coinfection. Furthermore, whether the leprosy subtype may influence the progression of the viral coinfection is unknown. All of these important and intriguing questions await prospective studies to definitively establish the actual relationship between these entities.

  2. Absence of C-type virus production in human leukemic B cell, T cell and null cell lines.

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    Ogura,Hajime

    1978-06-01

    Full Text Available Electron microscope observation of cultured human leukemic B cell, T cell and null cell lines and reverse transcriptase assay of the culture supernatants were all negative for the presence of C-type virus. Bat cell line, which propagates primate C-type viruses well, was cocultivated with the human leukemic cell lines, in the hope of amplification of virus if present. Three weeks after mixed culture, the culture supernatants were again examined for reverse transcriptase activity and the cells were tested for syncytia formation by cocultivation with rat XC, human KC and RSb cell lines. All these tests, except for the positive control using a simian sarcoma virus, were negative, suggesting that no C-type was produced from these human leukemic cell lines.

  3. Cell-specific targeting of lentiviral vectors mediated by fusion proteins derived from Sindbis virus, vesicular stomatitis virus, or avian sarcoma/leukosis virus

    Directory of Open Access Journals (Sweden)

    Marino Michael P

    2010-01-01

    Full Text Available Abstract Background The ability to efficiently and selectively target gene delivery vectors to specific cell types in vitro and in vivo remains one of the formidable challenges in gene therapy. We pursued two different strategies to target lentiviral vector delivery to specific cell types. In one of the strategies, vector particles bearing a membrane-bound stem cell factor sequence plus a separate fusion protein based either on Sindbis virus strain TR339 glycoproteins or the vesicular stomatitis virus G glycoprotein were used to selectively transduce cells expressing the corresponding stem cell factor receptor (c-kit. An alternative approach involved soluble avian sarcoma/leukosis virus receptors fused to cell-specific ligands including stem cell factor and erythropoietin for targeting lentiviral vectors pseudotyped with avian sarcoma/leukosis virus envelope proteins to cells that express the corresponding receptors. Results The titers of unconcentrated vector particles bearing Sindbis virus strain TR339 or vesicular stomatitis virus G fusion proteins plus stem cell factor in the context of c-kit expressing cells were up to 3.2 × 105 transducing units per ml while vector particles lacking the stem cell factor ligand displayed titers that were approximately 80 fold lower. On cells that lacked the c-kit receptor, the titers of stem cell factor-containing vectors were approximately 40 times lower compared to c-kit-expressing cells. Lentiviral vectors pseudotyped with avian sarcoma/leukosis virus subgroup A or B envelope proteins and bearing bi-functional bridge proteins encoding erythropoietin or stem cell factor fused to the soluble extracellular domains of the avian sarcoma/leukosis virus subgroup A or B receptors resulted in efficient transduction of erythropoietin receptor or c-kit-expressing cells. Transduction of erythropoietin receptor-expressing cells mediated by bi-functional bridge proteins was found to be dependent on the dose, the

  4. Alteration of cell cycle progression by Sindbis virus infection

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Ruirong; Saito, Kengo [Department of Molecular Virology, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan); Isegawa, Naohisa [Laboratory Animal Center, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan); Shirasawa, Hiroshi, E-mail: sirasawa@faculty.chiba-u.jp [Department of Molecular Virology, Graduate School of Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670 (Japan)

    2015-07-10

    We examined the impact of Sindbis virus (SINV) infection on cell cycle progression in a cancer cell line, HeLa, and a non-cancerous cell line, Vero. Cell cycle analyses showed that SINV infection is able to alter the cell cycle progression in both HeLa and Vero cells, but differently, especially during the early stage of infection. SINV infection affected the expression of several cell cycle regulators (CDK4, CDK6, cyclin E, p21, cyclin A and cyclin B) in HeLa cells and caused HeLa cells to accumulate in S phase during the early stage of infection. Monitoring SINV replication in HeLa and Vero cells expressing cell cycle indicators revealed that SINV which infected HeLa cells during G{sub 1} phase preferred to proliferate during S/G{sub 2} phase, and the average time interval for viral replication was significantly shorter in both HeLa and Vero cells infected during G{sub 1} phase than in cells infected during S/G{sub 2} phase. - Highlights: • SINV infection was able to alter the cell cycle progression of infected cancer cells. • SINV infection can affect the expression of cell cycle regulators. • SINV infection exhibited a preference for the timing of viral replication among the cell cycle phases.

  5. The Potato virus X TGBp3 protein associates with the ER network for virus cell-to-cell movement

    Science.gov (United States)

    Krishnamurthy, Konduru; Heppler, Marty; Mitra, Ruchira; Blancaflor, Elison; Payton, Mark; Nelson, Richard S.; Verchot-Lubicz, Jeanmarie

    2003-01-01

    Potato virus X (PVX) TGBp3 is required for virus cell-to-cell movement. Cell-to-cell movement of TGBp3 was studied using biolistic bombardment of plasmids expressing GFP:TGBp3. TGBp3 moves between cells in Nicotiana benthamiana, but requires TGBp1 to move in N. tabacum leaves. In tobacco leaves GFP:TGBp3 accumulated in a pattern resembling the endoplasmic reticulum (ER). To determine if the ER network is important for GFP:TGBp3 and for PVX cell-to-cell movement, a single mutation inhibiting membrane binding of TGBp3 was introduced into GFP:TGBp3 and into PVX. This mutation disrupted movement of GFP:TGBp3 and PVX. Brefeldin A, which disrupts the ER network, also inhibited GFP:TGBp3 movement in both Nicotiana species. Two deletion mutations, that do not affect membrane binding, hindered GFP:TGBp3 and PVX cell-to-cell movement. Plasmids expressing GFP:TGBp2 and GFP:TGBp3 were bombarded to several other PVX hosts and neither protein moved between adjacent cells. In most hosts, TGBp2 or TGBp3 cannot move cell-to-cell.

  6. Restriction of Rift Valley Fever Virus Virulence in Mosquito Cells

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    Sonja R. Gerrard

    2010-02-01

    Full Text Available Arboviruses are maintained in a natural cycle that requires blood-sucking arthropod and vertebrate hosts. Arboviruses are believed to persistently infect their arthropod host without overt pathology and cause acute infection with viremia in their vertebrate host. We have focused on elucidating how a specific arbovirus, Rift Valley fever (RVF virus, causes cytopathic effect in cells derived from vertebrates and non-cytopathic infection in cells derived from arthropods. We demonstrate that the vertebrate virulence factor, NSs, is functional in arthropod cells but is expressed at significantly lower levels in infected arthropod versus infected vertebrate cells.

  7. Interaction of ultraviolet-irradiated Herpes simplex virus type I with BSC-1 cells

    International Nuclear Information System (INIS)

    Ultraviolet irradiation of herpes simplex virus (HSV) did not affect the transfer of uncoated virus DNA to the nuclei of infected cells but the synthesis of virus DNA was suppressed. The virus-specific DNA polymerase was synthesized in cells infected with the u.v.-irradiated HF strain of HSV. In cells infected with the u.v.-irradiated KOS strain, the virus DNA polymerase activity was hardly detectable. The two strains of HSV differ in the sensitivity of the virus DNA polymerase gene to u.v.-irradiation. (author)

  8. Coevolution of cells and viruses in a persistent infection of foot-and-mouth disease virus in cell culture.

    OpenAIRE

    de la Torre, J C; Martínez-Salas, E; Diez, J; Villaverde, A; Gebauer, F; Rocha, E.; Dávila, M; Domingo, E

    1988-01-01

    Virus and cells evolve during serial passage of cloned BHK-21 cells persistently infected with foot-and-mouth disease virus (FMDV). These carrier cells, termed C1-BHK-Rc1 (J.C. de la Torre, M. Dávila, F. Sobrino, J. Ortín, and E. Domingo, Virology 145:24-35, 1985), become constitutively resistant to the parental FMDV C-S8c1. Curing of late-passage C1-BHK-Rc1 cells of FMDV by ribavirin treatment (J.C. de la Torre, B. Alarcón, E. Martínez-Salas, L. Carrasco, and E. Domingo, J. Virol. 61:233-235...

  9. Hsp90 inhibitors reduce influenza virus replication in cell culture

    International Nuclear Information System (INIS)

    The viral RNA polymerase complex of influenza A virus consists of three subunits PB1, PB2 and PA. Recently, the cellular chaperone Hsp90 was shown to play a role in nuclear import and assembly of the trimeric polymerase complex by binding to PB1 and PB2. Here we show that Hsp90 inhibitors, geldanamycin or its derivative 17-AAG, delay the growth of influenza virus in cell culture resulting in a 1-2 log reduction in viral titre early in infection. We suggest that this is caused by the reduced half-life of PB1 and PB2 and inhibition of nuclear import of PB1 and PA which lead to reduction in viral RNP assembly. Hsp90 inhibitors may represent a new class of antiviral compounds against influenza viruses

  10. Measles Virus Spread by Cell-Cell Contacts: Uncoupling of Contact-Mediated Receptor (CD46) Downregulation from Virus Uptake

    OpenAIRE

    firsching, Ruth; Christian J Buchholz; Schneider, Urs; Cattaneo, Roberto; ter Meulen, Volker; Schneider-Schaulies, Jürgen

    1999-01-01

    CD46, which serves as a receptor for measles virus (MV; strain Edmonston), is rapidly downregulated from the cell surface after contact with viral particles or infected cells. We show here that the same two CD46 complement control protein (CCP) domains responsible for primary MV attachment mediate its downregulation. Optimal downregulation efficiency was obtained with CD46 recombinants containing CCP domains 1 and 2, whereas CCP 1, alone and duplicated, induced a slight downregulation. Using ...

  11. Acute lymphocytic crisis following herpes simplex type 1 virus hepatitis in a nonimmunocompromised man: a case report

    Directory of Open Access Journals (Sweden)

    Plastiras Sotiris

    2009-08-01

    Full Text Available Abstract Introduction An increase in circulating lymphocytes can be seen following infections such as infectious mononucleosis and pertussis, or in lymphoproliferative disorders such as acute and chronic lymphocytic leukemia. Acute lymphocytic crisis following herpes simplex virus hepatitis has not been described in the literature. Case presentation A 52-year-old man was admitted to our hospital reporting low-grade fever for the previous seven days, and fatigue. During the fifth day of hospitalization, the patient developed a lymphocytic crisis and, after further tests the patient was diagnosed as having herpes simplex virus hepatitis. Conclusion This case report shows that herpes simplex virus type 1 is a possible cause of an acute lymphocytic crisis similar to other well known infectious agents such as Epstein–Barr virus, cytomegalovirus, human immunodeficiency virus, human herpes virus type 6, adenovirus, toxoplasma and human T-cell lymphotropic virus. Furthermore, this case report expands the clinical spectrum of herpes simplex virus hepatitis, since it is reported in a nonimmunocompromised patient presenting with atypical acute lymphocytic syndrome.

  12. Hemagglutinin of influenza A virus binds specifically to cell surface nucleolin and plays a role in virus internalization.

    Science.gov (United States)

    Chan, Che-Man; Chu, Hin; Zhang, Anna Jinxia; Leung, Lai-Han; Sze, Kong-Hung; Kao, Richard Yi-Tsun; Chik, Kenn Ka-Heng; To, Kelvin Kai-Wang; Chan, Jasper Fuk-Woo; Chen, Honglin; Jin, Dong-Yan; Liu, Liang; Yuen, Kwok-Yung

    2016-07-01

    The hemagglutinin (HA) protein of influenza A virus initiates cell entry by binding to sialic acids on target cells. In the current study, we demonstrated that in addition to sialic acids, influenza A/Puerto Rico/8/34 H1N1 (PR8) virus HA specifically binds to cell surface nucleolin (NCL). The interaction between HA and NCL was initially revealed with virus overlay protein binding assay (VOPBA) and subsequently verified with co-immunoprecipitation. Importantly, inhibiting cell surface NCL with NCL antibody, blocking PR8 viruses with purified NCL protein, or depleting endogenous NCL with siRNA all substantially reduced influenza virus internalization. We further demonstrated that NCL was a conserved cellular factor required for the entry of multiple influenza A viruses, including H1N1, H3N2, H5N1, and H7N9. Overall, our findings identified a novel role of NCL in influenza virus life cycle and established NCL as one of the host cell surface proteins for the entry of influenza A virus. PMID:27085069

  13. Infection of Mosquito Cells (C6/36) by Dengue-2 Virus Interferes with Subsequent Infection by Yellow Fever Virus.

    Science.gov (United States)

    Abrao, Emiliana Pereira; da Fonseca, Benedito Antônio Lopes

    2016-02-01

    Dengue is one of the most important diseases caused by arboviruses in the world. Yellow fever is another arthropod-borne disease of great importance to public health that is endemic to tropical regions of Africa and the Americas. Both yellow fever and dengue viruses are flaviviruses transmitted by Aedes aegypti mosquitoes, and then, it is reasonable to consider that in a given moment, mosquito cells could be coinfected by both viruses. Therefore, we decided to evaluate if sequential infections of dengue and yellow fever viruses (and vice-versa) in mosquito cells could affect the virus replication patterns. Using immunofluorescence and real-time PCR-based replication assays in Aedes albopictus C6/36 cells with single or sequential infections with both viruses, we demonstrated the occurrence of viral interference, also called superinfection exclusion, between these two viruses. Our results show that this interference pattern is particularly evident when cells were first infected with dengue virus and subsequently with yellow fever virus (YFV). Reduction in dengue virus replication, although to a lower extent, was also observed when C6/36 cells were initially infected with YFV followed by dengue virus infection. Although the importance that these findings have on nature is unknown, this study provides evidence, at the cellular level, of the occurrence of replication interference between dengue and yellow fever viruses and raises the question if superinfection exclusion could be a possible explanation, at least partially, for the reported lack of urban yellow fever occurrence in regions where a high level of dengue transmission occurs. PMID:26808727

  14. Target cells involved in radiation and radiation leukemia virus leukemogenesis

    International Nuclear Information System (INIS)

    Comparative studies concerned with the induction and early proliferation phases of preleukemic cells in relation to host environments using radiation or radiation leukemia virus as the leukemogenic agents, indicated different developmental pathways. The lack of thymus in mice exposed to fractionated irradiation did not prevent preleukemic cell induction but did interfere with the incidence of RadLV induced preleukemic cells. Thymus removal within several days following RadLV inoculation prevented the establishment of preleukemic cells in the bone marrow. The radiation induced preleukemic cells in the bone marrow. The radiation induced preleukemic cells were not lysed by anti-Thy-1.2 serum treatment and guinea pig complement whereas the RadLV induced ones were lysed to different degrees. Elimination of Thy-1.2 bearing cells from the virus induced preleukemic population reduced the development of overt T leukemias of donor origin. The thymus seemed of essential importance for establishing the proliferation of RadLV induced preleukemic cells but not for those induced by fractionated irradiation

  15. Remote Activation of Host Cell DNA Synthesis in Uninfected Cells Signaled by Infected Cells in Advance of Virus Transmission

    OpenAIRE

    Schmidt, Nora; Hennig, Thomas; Remigiusz A Serwa; Marchetti, Magda; O'Hare, Peter

    2015-01-01

    ABSTRACT Viruses modulate cellular processes and metabolism in diverse ways, but these are almost universally studied in the infected cell itself. Here, we study spatial organization of DNA synthesis during multiround transmission of herpes simplex virus (HSV) using pulse-labeling with ethynyl nucleotides and cycloaddition of azide fluorophores. We report a hitherto unknown and unexpected outcome of virus-host interaction. Consistent with the current understanding of the single-step growth cy...

  16. The V Protein of Canine Distemper Virus Is Required for Virus Replication in Human Epithelial Cells

    OpenAIRE

    Noriyuki Otsuki; Yuichiro Nakatsu; Toru Kubota; Tsuyoshi Sekizuka; Fumio Seki; Kouji Sakai; Makoto Kuroda; Ryoji Yamaguchi; Makoto Takeda

    2013-01-01

    Canine distemper virus (CDV) becomes able to use human receptors through a single amino acid substitution in the H protein. In addition, CDV strains possessing an intact C protein replicate well in human epithelial H358 cells. The present study showed that CDV strain 007Lm, which was isolated from lymph node tissue of a dog with distemper, failed to replicate in H358 cells, although it possessed an intact C protein. Sequence analyses suggested that a cysteine-to-tyrosine substitution at posit...

  17. Flow cytometric monitoring of influenza A virus infection in MDCK cells during vaccine production

    OpenAIRE

    Reichl Udo; Genzel Yvonne; Schulze-Horsel Josef

    2008-01-01

    Background In cell culture-based influenza vaccine production the monitoring of virus titres and cell physiology during infection is of great importance for process characterisation and optimisation. While conventional virus quantification methods give only virus titres in the culture broth, data obtained by fluorescence labelling of intracellular virus proteins provide additional information on infection dynamics. Flow cytometry represents a valuable tool to investigate the influences of ...

  18. Inhibition of respiratory syncytial virus-host cell interactions by mono- and diamidines.

    OpenAIRE

    Dubovi, E. J.; Geratz, J. D.; Shaver, S R; Tidwell, R. R.

    1981-01-01

    Several aromatic mono- and diamidines were found to block cell fusion induced by respiratory syncytial virus. The best inhibitors were able to achieve complete suppression of syncytium formation at a concentration of 1.0 microM. Inhibition occurred in respiratory syncytial virus-infected HEp-2 and CV-1 cells, but the same inhibitors were ineffective in preventing fusion induced by parainfluenza virus type 3. The fusion inhibitors did not reduce single-cycle virus yields, but did reduce multip...

  19. Hepatitis B virus antigens impair NK cell function.

    Science.gov (United States)

    Yang, Yinli; Han, Qiuju; Zhang, Cai; Xiao, Min; Zhang, Jian

    2016-09-01

    An inadequate immune response of the host is thought to be a critical factor causing chronic hepatitis B virus (CHB) infection. Natural killer (NK) cells, as one of the key players in the eradication and control of viral infections, were functionally impaired in CHB patients, which might contribute to viral persistence. Here, we reported that HBV antigens HBsAg and HBeAg directly inhibited NK cell function. HBsAg and/or HBeAg blocked NK cell activation, cytokine production and cytotoxic granule release in human NK cell-line NK-92 cells, which might be related to the downregulation of activating receptors and upregulation of inhibitory receptor. Furthermore, the underlying mechanisms likely involved the suppression of STAT1, NF-κB and p38 MAPK pathways. These findings implicated that HBV antigen-mediated inhibition of NK cells might be an efficient strategy for HBV evasion, targeting the early antiviral responses mediated by NK cells and resulting in the establishment of chronic virus infection. Therefore, this study revealed the relationship between viral antigens and human immune function, especially a potential important interaction between HBV and innate immune responses. PMID:27341035

  20. Characterization of cell lines stably transfected with rubella virus replicons

    Energy Technology Data Exchange (ETDEWEB)

    Tzeng, Wen-Pin; Xu, Jie [Department of Biology, Georgia State University, P.O. Box 4010, Atlanta GA 30302-4010 (United States); Frey, Teryl K., E-mail: tfrey@gsu.edu [Department of Biology, Georgia State University, P.O. Box 4010, Atlanta GA 30302-4010 (United States)

    2012-07-20

    Rubella virus (RUBV) replicons expressing a drug resistance gene and a gene of interest were used to select cell lines uniformly harboring the replicon. Replicons expressing GFP and a virus capsid protein GFP fusion (C-GFP) were compared. Vero or BHK cells transfected with either replicon survived drug selection and grew into a monolayer. However, survival was {approx}9-fold greater following transfection with the C-GFP-replicon than with the GFP-expressing replicon and while the C-GFP-replicon cells grew similarly to non-transfected cells, the GFP-replicon cells grew slower. Neither was due to the ability of the CP to enhance RNA synthesis but survival during drug selection was correlated with the ability of CP to inhibit apoptosis. Additionally, C-GFP-replicon cells were not cured of the replicon in the absence of drug selection. Interferon-alpha suppressed replicon RNA and protein synthesis, but did not cure the cells, explaining in part the ability of RUBV to establish persistent infections.

  1. Immune cells: more than simple carriers for systemic delivery of oncolytic viruses

    Directory of Open Access Journals (Sweden)

    Eisenstein S

    2014-11-01

    Full Text Available Samuel Eisenstein,1 Shu-Hsia Chen,2 Ping-Ying Pan21Department of Surgery, 2Department of Oncological Sciences and Tisch Cancer Institute, The Icahn School of Medicine at Mount Sinai, New York, NY, USAAbstract: Oncolytic virotherapy on its own has numerous drawbacks, including an inability of the virus to actively target tumor cells and systemic toxicities at the high doses necessary to effectively treat tumors. Addition of immune cell-based carriers of oncolytic viruses holds promise as a technique in which oncolytic virus can be delivered directly to tumors in smaller and less toxic doses. Interestingly, the cell carriers themselves have also demonstrated antitumor effects, which can be augmented further by tailoring the appropriate oncolytic virus to the appropriate cell type. This review discusses the multiple factors that go into devising an effective, cell-based delivery system for oncolytic viruses.Keywords: oncolytic virus, cell carrier, immune cells, cancer therapy, myeloid-derived suppressor cells

  2. The V protein of canine distemper virus is required for virus replication in human epithelial cells.

    Directory of Open Access Journals (Sweden)

    Noriyuki Otsuki

    Full Text Available Canine distemper virus (CDV becomes able to use human receptors through a single amino acid substitution in the H protein. In addition, CDV strains possessing an intact C protein replicate well in human epithelial H358 cells. The present study showed that CDV strain 007Lm, which was isolated from lymph node tissue of a dog with distemper, failed to replicate in H358 cells, although it possessed an intact C protein. Sequence analyses suggested that a cysteine-to-tyrosine substitution at position 267 of the V protein caused this growth defect. Analyses using H358 cells constitutively expressing the CDV V protein showed that the V protein with a cysteine, but not that with a tyrosine, at this position effectively blocked the interferon-stimulated signal transduction pathway, and supported virus replication of 007Lm in H358 cells. Thus, the V protein as well as the C protein appears to be functional and essential for CDV replication in human epithelial cells.

  3. No detection of BK virus, JC virus, KI, WU and Merkel cell polyomaviruses in cerebrospinal fluid of patients with neurological complications after hematopoetic stem cell transplantation.

    Science.gov (United States)

    Rubin, J; Giraud, G; Priftakis, P; Wide, K; Gustafsson, B; Ramqvist, T; Dalianis, T

    2011-10-01

    Neurological complications, often due to viral reactivation, after allogeneic hematopoetic stem cell transplantation (HSCT) are associated with increased mortality. Here, cerebrospinal fluid from 20 HSCT patients with neurological symptoms were analyzed and found to be negative by PCR for BK virus, JC virus, KI, WU and Merkel cell polyomavirus DNA. PMID:21965766

  4. Initial interaction of herpes simplex virus with cells is binding to heparan sulfate.

    OpenAIRE

    WuDunn, D; Spear, P G

    1989-01-01

    We have shown that cell surface heparan sulfate serves as the initial receptor for both serotypes of herpes simplex virus (HSV). We found that virions could bind to heparin, a related glycosaminoglycan, and that heparin blocked virus adsorption. Agents known to bind to cell surface heparan sulfate blocked viral adsorption and infection. Enzymatic digestion of cell surface heparan sulfate but not of dermatan sulfate or chondroitin sulfate concomitantly reduced the binding of virus to the cells...

  5. Myxoma virus M063R is a host range gene essential for virus replication in rabbit cells.

    Science.gov (United States)

    Barrett, John W; Shun Chang, Chew; Wang, Gen; Werden, Steven J; Shao, Zhuhong; Barrett, Catherine; Gao, Xiujuan; Belsito, Tara A; Villenevue, Danielle; McFadden, Grant

    2007-04-25

    The myxoma virus M063R gene product exhibits some sequence similarity to the poxvirus host range gene, C7L, of vaccinia virus. To address the potential host range function of the M063R gene product in rabbits, a deletion mutant of myxoma virus (vMyx63KO) was generated and characterized. vMyx63KO replicated to normal titre levels and produced foci that were indistinguishable from those produced by MV in vitro in a monkey kidney cell line (BGMK) that are permissive for wild type MV. However, vMyx63KO failed to replicate in all rabbit cell lines tested, including both primary and established cells lines, as well as cells derived from a variety of tissues. M063R expression was not required for myxoma virus binding, entry or early gene expression, whereas DNA replication was aborted and late genes were not expressed in vMyx63KO infected rabbit cells. Thus, the replication block for vMyx63KO in rabbit cells preceded the stage of late gene expression and DNA replication. Finally, an in vivo pathogenesis study indicated that vMyx63KO failed to cause any signs of classic myxomatosis in infected rabbits, but functioned as a non-replicating vaccine and provided protection for subsequent challenge by wild type myxoma virus. Altogether, these observations demonstrate that M063R plays a critical role in determining the host specificity of myxoma virus in rabbit cells. PMID:17184804

  6. Dengue virus-specific, human CD4+ CD8- cytotoxic T-cell clones: multiple patterns of virus cross-reactivity recognized by NS3-specific T-cell clones.

    OpenAIRE

    Kurane, I; Brinton, M A; Samson, A L; Ennis, F A

    1991-01-01

    Thirteen dengue virus-specific, cytotoxic CD4+ CD8- T-cell clones were established from a donor who was infected with dengue virus type 3. These clones were examined for virus specificity and human leukocyte antigen (HLA) restriction in cytotoxic assays. Six patterns of virus specificities were determined. Two serotype-specific clones recognized only dengue virus type 3. Two dengue virus subcomplex-specific clones recognized dengue virus types 2, 3, and 4, and one subcomplex-specific clone re...

  7. Optimization Manufacture of Virus- and Tumor-Specific T Cells

    Directory of Open Access Journals (Sweden)

    Natalia Lapteva

    2011-01-01

    Full Text Available Although ex vivo expanded T cells are currently widely used in pre-clinical and clinical trials, the complexity of manufacture remains a major impediment for broader application. In this review we discuss current protocols for the ex vivo expansion of virus- and tumor-specific T cells and describe our experience in manufacture optimization using a gas-permeable static culture flask (G-Rex. This innovative device has revolutionized the manufacture process by allowing us to increase cell yields while decreasing the frequency of cell manipulation and in vitro culture time. It is now being used in good manufacturing practice (GMP facilities for clinical cell production in our institution as well as many others in the US and worldwide.

  8. Immunogenic cell death by oncolytic herpes simplex virus type 1 in squamous cell carcinoma cells.

    Science.gov (United States)

    Takasu, A; Masui, A; Hamada, M; Imai, T; Iwai, S; Yura, Y

    2016-04-01

    Molecules essential for the induction of immunogenic cell death (ICD) are called damage-associated molecular patterns (DAMPs). The effects of oncolytic herpes simplex virus type 1 (HSV-1) on the production of DAMPs were examined in squamous cell carcinoma (SCC) cells. The cytopathic effects of HSV-1 RH2 were observed in mouse SCCVII cells infected at a high multiplicity of infection (MOI), and the amounts of viable cells were decreased. After being infected with RH2, ATP and high mobility group box 1 (HMGB1) were released extracellulary, while calreticulin (CRT) translocated to the cell membrane. A flow-cytometric analysis revealed an increase in the number of annexin-V and propidium iodide (PI)-stained cells; and the amount of cleaved poly (ADP-ribose) polymerase (PARP) was increased. The killing effect of RH2 was reduced by pan-caspase inhibitor z-VAD-fmk and the caspase-1 inhibitor z-YVAD-fmk, suggesting the involvement of apoptosis and pyroptosis. In C3H mice bearing synergic SCCVII tumors, the growth of tumors injected with the supernatant of RH2-infected cells was less than that of tumors injected with phosphate-buffered saline (PBS). These results indicate that oncolytic HSV-1 RH2 produces DAMPs from SCC cells to induce cell death. This may contribute to the enhancement of tumor immunity by oncolytic HSV-1. PMID:26987291

  9. 6K2-induced vesicles can move cell to cell during turnip mosaic virus infection

    OpenAIRE

    Jean-FrançoisLaliberté; HuanquanZheng

    2013-01-01

    To successfully infect plants, viruses replicate in an initially infected cell and then move to neighboring cells through plasmodesmata (PDs). However, the nature of the viral entity that crosses over the cell barrier into non-infected ones is not clear. The membrane-associated 6K2 protein of turnip mosaic virus (TuMV) induces the formation of vesicles involved in the replication and intracellular movement of viral RNA. This study shows that 6K2-induced vesicles trafficked towards the plasma ...

  10. Cell culture systems for the hepatitis C virus

    Institute of Scientific and Technical Information of China (English)

    Gilles Duverlie; Czeslaw Wychowski

    2007-01-01

    Since the discovery of HCV in 1989, the lack of a cell culture system has hampered research progress on this important human pathogen. No robust system has been obtained by empiric approaches, and HCV cell culture remained hypothetical until 2005. The construction of functional molecular clones has served as a starting point to reconstitute a consensus infectious cDNA that was able to transcribe infectious HCV RNAs as shown by intrahepatic inoculation in a chimpanzee. Other consensus clones have been selected and established in a human hepatoma cell line as replicons, i.e. self-replicating subgenomic or genomic viral RNAs. However, these replicons did not support production of infectious virus. Interestingly, some full-length replicons could be established without adaptive mutations and one of them was able to replicate at very high levels and to release virus particles that are infectious in cell culture and in vivo. This new cell culture system represents a major breakthrough in the HCV field and should enable a broad range of basic and applied studies to be achieved.

  11. Live-Cell Imaging of Vaccinia Virus Recombination

    Science.gov (United States)

    Paszkowski, Patrick; Noyce, Ryan S.; Evans, David H.

    2016-01-01

    Recombination between co-infecting poxviruses provides an important mechanism for generating the genetic diversity that underpins evolution. However, poxviruses replicate in membrane-bound cytoplasmic structures known as factories or virosomes. These are enclosed structures that could impede DNA mixing between co-infecting viruses, and mixing would seem to be essential for this process. We hypothesize that virosome fusion events would be a prerequisite for recombination between co-infecting poxviruses, and this requirement could delay or limit viral recombination. We have engineered vaccinia virus (VACV) to express overlapping portions of mCherry fluorescent protein fused to a cro DNA-binding element. In cells also expressing an EGFP-cro fusion protein, this permits live tracking of virus DNA and genetic recombination using confocal microscopy. Our studies show that different types of recombination events exhibit different timing patterns, depending upon the relative locations of the recombining elements. Recombination between partly duplicated sequences is detected soon after post-replicative genes are expressed, as long as the reporter gene sequences are located in cis within an infecting genome. The same kinetics are also observed when the recombining elements are divided between VACV and transfected DNA. In contrast, recombination is delayed when the recombining sequences are located on different co-infecting viruses, and mature recombinants aren’t detected until well after late gene expression is well established. The delay supports the hypothesis that factories impede inter-viral recombination, but even after factories merge there remain further constraints limiting virus DNA mixing and recombinant gene assembly. This delay could be related to the continued presence of ER-derived membranes within the fused virosomes, membranes that may once have wrapped individual factories. PMID:27525721

  12. Hepatitis G virus

    Institute of Scientific and Technical Information of China (English)

    Vasiliy Ivanovich Reshetnyak; Tatiana Igorevna Karlovich; Ljudmila Urievna Ilchenko

    2008-01-01

    A number of new hepatitis viruses (G,TT,SEN) were discovered late in the past century.We review the data available in the literature and our own findings suggesting that the new hepatitis G virus (HGV),disclosed in the late 1990s,has been rather well studied.Analysis of many studies dealing with HGV mainly suggests the lymphotropicity of this virus.HGV or GBV-C has been ascertained to influence course and prognosis in the HIV-infected patient.Until now,the frequent presence of GBV-C in coinfections,hematological diseases,and biliary pathology gives no grounds to determine it as an "accidental tourist" that is of no significance.The similarity in properties of GBV-C and hepatitis C virus (HCV) offers the possibility of using HGV,and its induced experimental infection,as a model to study hepatitis C and to develop a hepatitis C vaccine.

  13. [Research Progress in Black Queen Cell Virus Causing Disease].

    Science.gov (United States)

    Yang, Qian; Zhang, Jian; Song, Zhanyun; Zheng, Yan; Wang, Xianghui; Sui, Jiachen; Wang, Zhenguo; Mou, Jun

    2015-05-01

    In nature, honeybees are the most important pollinators. They play a vital role in both protecting the diversity of natural ecosystems, and maintaining the yield-improving effects of agroecosystems. But in recent years, epidemic disease in bees has caused huge losses. Black Queen Cell Virus (BQCV) is a bee pathogen that was first reported in 1955. It mainly infects bee larvae and pupae, making their bodies turn dark and black, and causing a massive decrease in the bee population. More specifically, the virus makes the exterior of the cell walls in the larvae and pupae turn black. BQCV is a seasonal epidemic, spread by means horizontal and vertical transmission, and is often unapparent. BQCV not only infects a variety of bee species, but also spiders, centipedes and other arthropods. It can also be coinfected with other honeybee viruses. In recent years, research has shown that the Nosema intestinal parasite plays an important role in BQCV transmission and bees carrying Nosema that become infected with BQCV have increased mortality. Here we summarize current research on the incidence, prevalence, geographical distribution and transmission of BQCV. PMID:26470541

  14. Functional Analysis of West Nile Virus Proteins in Human Cells.

    Science.gov (United States)

    Kaufusi, Pakieli H; Tseng, Alanna; Nerurkar, Vivek R

    2016-01-01

    West Nile Virus (WNV) lineage 2 strains have been responsible for large outbreaks of neuroinvasive disease in the United States and Europe between 1999 and 2012. Different strains in this lineage have previously been shown to produce either severe or mild neuroinvasive disease in mice. Phylogenetic and amino acid comparisons between highly or less virulent lineage 2 strains have demonstrated that the nonstructural (NS) gene(s) were most variable. However, the roles of some of the NS proteins in virus life cycle are unknown. The aim of this chapter is to describe simple computational and experimental approaches that can be used to: (1) explore the possible roles of the NS proteins in virus life cycle and (2) test whether the subtle amino acid changes in WNV NS gene products contributed to the evolution of more virulent strains. The computational approaches include methods based on: (1) sequence similarity, (2) sequence motifs, and (3) protein membrane topology predictions. Highlighted experimental procedures include: (1) isolation of viral RNA from WNV-infected cells, (2) cDNA synthesis and PCR amplification of WNV genes, (3) cloning into GFP expression vector, (4) bacterial transformation, (5) plasmid isolation and purification, (6) transfection using activated dendrimers (Polyfect), and (7) immunofluorescence staining of transfected mammalian cells. PMID:27188549

  15. Human Vγ9Vδ2-T cells efficiently kill influenza virus-infected lung alveolar epithelial cells

    Science.gov (United States)

    Li, Hong; Xiang, Zheng; Feng, Ting; Li, Jinrong; Liu, Yinping; Fan, Yingying; Lu, Qiao; Yin, Zhongwei; Yu, Meixing; Shen, Chongyang; Tu, Wenwei

    2013-01-01

    γδ-T cells play an indispensable role in host defense against different viruses, including influenza A virus. However, whether these cells have cytotoxic activity against influenza virus-infected lung alveolar epithelial cells and subsequently contribute to virus clearance remains unknown. Using influenza virus-infected A549 cells, human lung alveolar epithelial cells, we investigated the cytotoxic activity of aminobisphosphonate pamidronate (PAM)-expanded human Vγ9Vδ2-T cells and their underlying mechanisms. We found that PAM could selectively activate and expand human Vγ9Vδ2-T cells. PAM-expanded human Vγ9Vδ2-T cells efficiently killed influenza virus-infected lung alveolar epithelial cells and inhibited virus replication. The cytotoxic activity of PAM-expanded Vγ9Vδ2-T cells was dependent on cell-to-cell contact and required NKG2D activation. Perforin–granzyme B, tumor-necrosis factor-related apoptosis-inducing ligand (TRAIL) and Fas–Fas ligand (FasL) pathways were involved in their cytotoxicity. Our study suggests that targeting γδ-T cells by PAM can potentially offer an alternative option for the treatment of influenza virus. PMID:23353835

  16. Determining Influenza Virus Shedding at Different Time Points in Madin-Darby Canine Kidney Cell Line

    Directory of Open Access Journals (Sweden)

    Asghar Abdoli

    2013-01-01

    Full Text Available Objective: Monitoring of influenza virus shedding and optimization of multiplicities of infection (MOI is important in the investigation of a virus one step growth cycle and for obtaining a high yield of virus in vaccine development and conventional basic diagnostic methods. However, eluted infectious viruses may still be present immediately after virus inoculation and when cells are washed following virus cultivation which may lead to a false positive virus infectivity assay.Materials and Methods: In this experimental study, we investigated influenza virus progeny production in Madin-Darby canine kidney (MDCK cells with five different MOI at determined time points. The results were analyzed by end point titration tests and immunofluorescence assay.Results: Higher titers of eluted virus were observed following a high MOI inoculation of virus in cell culture. Most probably, this was the result of sialic acid residues from viral hemagglutin in proteins that were cleaved by neuraminidase glycoproteins on the surface of the influenza virus, which promoted viral spread from the host cell to the culture supernatant or during endocytosis, where viruses recycle to the cell surface by recycling endosomes which culminated in virus shedding without replication.Conclusion: We demonstrated that the pattern of influenza virus progeny production was dose-dependent and not uniform. This production was influenced by several factors, particularly MOI. Understanding the exact features of viral particle propagation has a major impact in producing high virus yields in the development of vaccines. Use of lower MOI (0.01 could result in accurate, precise quantitative assays in virus diagnosis and titration methods.

  17. Host Range Expansion of Honey Bee Black Queen Cell Virus in the Bumble Bee, Bombus huntii

    Science.gov (United States)

    Honey bee viruses display a host range that is not restricted to their original host, European honey bees, Apis mellifera. Here we provide the first evidence that Black Queen Cell Virus (BQCV), one of the most prevalent honey bee viruses, can cause an infection in both laboratory-reared and field-co...

  18. Entry of Oncolytic Herpes Simplex Virus into Human Squamous Cell Carcinoma Cells by Ultrasound

    Directory of Open Access Journals (Sweden)

    Shusuke Okunaga

    2015-10-01

    Full Text Available Low-intensity ultrasound is a useful method to introduce materials into cells due to the transient formation of micropores, called sonoporations, on the cell membrane. Whether oncolytic herpes simplex virus type 1 (HSV-1 can be introduced into oral squamous cell carcinoma (SCC cells through membrane pores remains undetermined. Human SCC cell line SAS and oncolytic HSV-1 RH2, which was deficient in the 134.5 gene and fusogenic, were used. Cells were exposed to ultrasound in the presence or absence of microbubbles. The increase of virus entry was estimated by plaque numbers. Viral infection was hardly established without the adsorption step, but plaque number was increased by the exposure of HSV-1-inoculated cells to ultrasound. Plaque number was also increased even if SAS cells were exposed to ultrasound and inoculated with RH2 without the adsorption step. This effect was abolished when the interval from ultrasound exposure to virus inoculation was prolonged. Scanning electron microscopy revealed depressed spots on the cell surface after exposure to ultrasound. These results suggest that oncolytic HSV-1 RH2 can be introduced into SAS cells through ultrasound-mediated pores of the cell membrane that are resealed after an interval.

  19. Cell tropism and pathogenesis of measles virus in monkeys

    Directory of Open Access Journals (Sweden)

    KaoruTakeuchi

    2012-01-01

    Full Text Available Measles virus (MV is an enveloped negative strand RNA virus belonging to the family of Paramyxoviridae, genus Morbillivirus, and causes one of the most contagious diseases in humans. Experimentally infected non-human primates are used as animal models for studies of the pathogenesis of human measles. We established a reverse genetics system based on a highly pathogenic wild-type MV (IC-B strain. Infection of monkeys with recombinant MV strains generated by reverse genetics enabled analysis of the molecular basis of MV pathogenesis. In addition, recombinant wild-type MV strains expressing enhanced green fluorescent protein enable visual tracking of MV-infected cells in vitro and in vivo. To date, 3 different molecules have been identified as receptors for MV. Signaling lymphocyte activation molecule (SLAM, also called CD150, expressed on immune cells, is a major receptor for MV. CD46, ubiquitously expressed in all nucleated cells in humans and monkeys, is a receptor for vaccine and laboratory strains of MV. The newly identified nectin-4 (also called PVRL4 is an epithelial cell receptor for MV. The impact of MV receptor usage in vivo on disease outcomes is now under investigation.

  20. Formation of infectious hybrid virions with gibbon ape leukemia virus and human T-cell leukemia virus retroviral envelope glycoproteins and the gag and pol proteins of Moloney murine leukemia virus.

    OpenAIRE

    C. Wilson; Reitz, M S; Okayama, H; Eiden, M V

    1989-01-01

    The gibbon ape leukemia virus, SEATO strain, and human T-cell leukemia virus type I envelope glycoproteins can be functionally assembled with a Moloney murine leukemia virus core into infectious particles. The envelope-host cell receptor interaction is the major determinant of the host cell specificity for these hybrid virions.

  1. Sensitivity of Three Cell Lines to Japanese Encephalitis Virus Infectivity Assay

    OpenAIRE

    Daji, Hu; Morita, Kouichi; Igarashi, Akira

    1992-01-01

    Comparative sensitivity test on three established cell lines for the plaque formation of Japanese encephalitis (JE) virus showed that the highest infectivity was recorded on Vero, followed by BHK21 and then Hep-2 cell lines. The result indicated that these cell lines possess different sensitivity to JE virus in the early stage of infection.

  2. Influenza A virus survival in water is influenced by the origin species of the host cell

    OpenAIRE

    Shigematsu, Sayuri; Dublineau, Amélie; Sawoo, Olivier; Batéjat, Christophe; Matsuyama, Toshifumi; Leclercq, India; Manuguerra, Jean-Claude

    2014-01-01

    Background Influenza A viruses have an envelope made of a lipid bilayer and two surface glycoproteins, the hemagglutinin and the neuraminidase. The structure of the virus is directly dependent on the genetic makeup of the viral genome except the glycosylation moieties and the composition of the lipid bilayer. They both depend on the host cell and are in direct contact with the environment, such as air or water. Virus survival is important for virus transmission from contaminated waters in the...

  3. Influenza A virus survival in water is influenced by the origin species of the host cell

    OpenAIRE

    Shigematsu, Sayuri; Dublineau, Amélie; Sawoo, Olivier; Batéjat, Christophe; Matsuyama, Toshifumi; Leclercq, India; Manuguerra, Jean-Claude

    2014-01-01

    Background: Influenza A viruses have an envelope made of a lipid bilayer and two surface glycoproteins, the hemagglutinin and the neuraminidase. The structure of the virus is directly dependent on the genetic makeup of the viral genome except the glycosylation moieties and the composition of the lipid bilayer. They both depend on the host cell and are in direct contact with the environment, such as air or water. Virus survival is important for virus transmission from contaminated waters in th...

  4. Effect of caffeine on the ultraviolet light induction of SV40 virus from transformed hamster cells

    International Nuclear Information System (INIS)

    The effect of caffeine on the uv light induction of SV40 virus from two transformed hamster cell lines heterogeneous for the induction of infectious virus was studied. The amount of virus induced was significantly increased in both cell lines when exposure to uv light was followed by treatment with caffeine. Caffeine in the absence of uv irradiation did not stimulate virus induction, nor did it stimulate SV40 replication in a lytic infection. There was an apparent difference in the concentrations of caffeine which maximally stimulated SV40 virus induction in the two cell lines. This effect could not be explained by differences in cell survival after exposure to uv light and caffeine. Since caffeine is known to cause the accumulation of gaps formed in DNA during postreplication repair of uv-irradiated rodent cells, our results support the hypothesis that the formation of gaps or breaks in DNA is an important early step in virus induction

  5. A chimeric measles virus with a lentiviral envelope replicates exclusively in CD4+/CCR5+ cells

    International Nuclear Information System (INIS)

    We generated a replicating chimeric measles virus in which the hemagglutinin and fusion surface glycoproteins were replaced with the gp160 envelope glycoprotein of simian immunodeficiency virus (SIVmac239). Based on a previously cloned live-attenuated Schwarz vaccine strain of measles virus (MV), this chimera was rescued at high titers using reverse genetics in CD4+ target cells. Cytopathic effect consisted in the presence of large cell aggregates evolving to form syncytia, as observed during SIV infection. The morphology of the chimeric virus was identical to that of the parent MV particles. The presence of SIV gp160 as the only envelope protein on chimeric particles surface altered the cell tropism of the new virus from CD46+ to CD4+ cells. Used as an HIV candidate vaccine, this MV/SIVenv chimeric virus would mimic transient HIV-like infection, benefiting both from HIV-like tropism and the capacity of MV to replicate in dendritic cells, macrophages and lymphocytes.

  6. Human neuronal cell protein responses to Nipah virus infection

    Directory of Open Access Journals (Sweden)

    Hassan Sharifah

    2007-06-01

    Full Text Available Abstract Background Nipah virus (NiV, a recently discovered zoonotic virus infects and replicates in several human cell types. Its replication in human neuronal cells, however, is less efficient in comparison to other fully susceptible cells. In the present study, the SK-N-MC human neuronal cell protein response to NiV infection is examined using proteomic approaches. Results Method for separation of the NiV-infected human neuronal cell proteins using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE was established. At least 800 protein spots were resolved of which seven were unique, six were significantly up-regulated and eight were significantly down-regulated. Six of these altered proteins were identified using mass spectrometry (MS and confirmed using MS/MS. The heterogenous nuclear ribonucleoprotein (hnRNP F, guanine nucleotide binding protein (G protein, voltage-dependent anion channel 2 (VDAC2 and cytochrome bc1 were present in abundance in the NiV-infected SK-N-MC cells in contrast to hnRNPs H and H2 that were significantly down-regulated. Conclusion Several human neuronal cell proteins that are differentially expressed following NiV infection are identified. The proteins are associated with various cellular functions and their abundance reflects their significance in the cytopathologic responses to the infection and the regulation of NiV replication. The potential importance of the ratio of hnRNP F, and hnRNPs H and H2 in regulation of NiV replication, the association of the mitochondrial protein with the cytopathologic responses to the infection and induction of apoptosis are highlighted.

  7. Mielopatia associada ao vírus linfotrópico humanode células T do tipo 1 (HTLV-1 Human T-cell lymphotropic virus type 1(HTLV-1 - associated myelopathy

    Directory of Open Access Journals (Sweden)

    João Gabriel Ramos Ribas

    2002-08-01

    Full Text Available A mielopatia associada ao HTLV-1 (HAM, também conhecida como paraparesia espástica tropical (TSP, é uma doença desmielinizante crônica progressiva que afeta a medula espinal e a substância branca do cérebro. Menos de 5% dos portadores crônicos do HTLV-1 desenvolverão essa complicação. As primeiras manifestações da doença ocorrem na quarta década da vida e observa-se relação mulher/homem de 2:1. Os distúrbios da marcha, a fraqueza e o enrijecimento dos membros inferiores constituem os principais sinais e sintomas de apresentação da mielopatia. As extremidades inferiores são afetadas com maior intensidade do que as extremidades superiores. A espasticidade pode variar de moderada a intensa e a dor lombar baixa revela-se comum. Com a progressão da doença há, com freqüência, disfunção vesical e intestinal. O envolvimento sensitivo mostra-se discreto e manifesta-se com graus variados de perdas sensitivas e sensação de disestesia. A ressonância nuclear magnética do sistema nervoso pode resultar normal ou revelar atrofia da medula espinal e alterações inespecíficas no cérebro. Há evidências de envolvimento imunológico na gênese da lesão medular. Não há tratamento eficaz para a mielopatia. Os corticoesteróides e o interferon-a produziram benefícios transitórios no tratamento da doença. Não houve melhora da marcha e da disfunção vesical em pacientes que usaram o danazol, um esteróide anabolizante. O valor da zidovudina (anti-retroviral no tratamento da mielopatia ainda não se encontra definido.HTLV-1-associated myelopathy (HAM, also known as tropical spastic paraparesis (TSP, is a chronic progressive demyelinating disease that affects the spinal cord and white matter of the central nervous system. The lifetime incidence of HAM in HTLV-1 carriers is estimated to be less than 5%. Typical time of onset is in the fourth decade of life, with a female-to-male rate of 2:1. Gait disturbance and weakness and stiffness of the lower limbs are common presenting signs and symptoms of HAM. Lower extremities are affected to a much greater degree than upper extremities. Spasticity may be moderate to severe, and lower back pain is common. As the disease progresses, bladder and bowel dysfunction can occur. Sensory involvement is generally mild and can result in a variable degree of sensory loss and dysesthesia. Results of magnetic resonance imaging may be normal, or the scans show atrophy of the spinal cord and nonspecific lesions in the brain. Immunologic evidence suggests that an immune mechanism may play a role in the development of HAM. There is no effective treatment for the myelopathy. Corticosteroids, and INF-gamma may produce transient responses. Danazol, an anabolic steroid, does not improve gait and bladder function. The value of zidovudine (anti-retroviral agent in the treatment has not been defined yet.

  8. Influenza H5N1 virus infection of polarized human alveolar epithelial cells and lung microvascular endothelial cells

    Directory of Open Access Journals (Sweden)

    Yuen Kit M

    2009-10-01

    Full Text Available Abstract Background Highly pathogenic avian influenza (HPAI H5N1 virus is entrenched in poultry in Asia and Africa and continues to infect humans zoonotically causing acute respiratory disease syndrome and death. There is evidence that the virus may sometimes spread beyond respiratory tract to cause disseminated infection. The primary target cell for HPAI H5N1 virus in human lung is the alveolar epithelial cell. Alveolar epithelium and its adjacent lung microvascular endothelium form host barriers to the initiation of infection and dissemination of influenza H5N1 infection in humans. These are polarized cells and the polarity of influenza virus entry and egress as well as the secretion of cytokines and chemokines from the virus infected cells are likely to be central to the pathogenesis of human H5N1 disease. Aim To study influenza A (H5N1 virus replication and host innate immune responses in polarized primary human alveolar epithelial cells and lung microvascular endothelial cells and its relevance to the pathogenesis of human H5N1 disease. Methods We use an in vitro model of polarized primary human alveolar epithelial cells and lung microvascular endothelial cells grown in transwell culture inserts to compare infection with influenza A subtype H1N1 and H5N1 viruses via the apical or basolateral surfaces. Results We demonstrate that both influenza H1N1 and H5N1 viruses efficiently infect alveolar epithelial cells from both apical and basolateral surface of the epithelium but release of newly formed virus is mainly from the apical side of the epithelium. In contrast, influenza H5N1 virus, but not H1N1 virus, efficiently infected polarized microvascular endothelial cells from both apical and basolateral aspects. This provides a mechanistic explanation for how H5N1 virus may infect the lung from systemic circulation. Epidemiological evidence has implicated ingestion of virus-contaminated foods as the source of infection in some instances and our

  9. Structure and Cell Biology of Archaeal Virus STIV

    OpenAIRE

    Fu, Chi-yu; Johnson, John E.

    2012-01-01

    Recent investigations of archaeal viruses have revealed novel features of their structures and life cycles when compared to eukaryotic and bacterial viruses, yet there are structure-based unifying themes suggesting common ancestral relationships among dsDNA viruses in the three kingdoms of life. Sulfolobus solfataricus and the infecting virus Sulfolobus turreted icosahedral virus (STIV) is one of the well-established model systems to study archaeal virus replication and viral-host interaction...

  10. Repair and mutagenesis of herpes simplex virus in UV-irradiated monkey cells

    International Nuclear Information System (INIS)

    Mutagenic repair in mammalian cells was investigated by determining the mutagenesis of UV-irradiated or unirradiated herpes simplex virus in UV-irradiated CV-1 monkey kidney cells. These results were compared with the results for UV-enhanced virus reactivation (UVER) in the same experimental situation. High and low multiplicities of infection were used to determine the effects of multiplicity reactivation (MR). UVER and MR were readily demonstrable and were approximately equal in amount in an infectious center assay. For this study, a forward-mutation assay was developed to detect virus mutants resistant to iododeoxycytidine (ICdR), probably an indication of the mutant virus being defective at its thymidine kinase locus. ICdR-resistant mutants did not have a growth advantage over wild-type virus in irradiated or unirradiated cells. Thus, higher fractions of mutant virus indicated greater mutagenesis during virus repair and/or replication. The data showed that: (1) unirradiated virus was mutated in unirradiated cells, providing a background level of mutagenesis; (2) unirradiated virus was mutated about 40% more in irradiated cells, indicating that virus replication (DNA synthesis) became more mutagenic as a result of cell irradiation; (3) irradiated virus was mutated much more (about 6-fold) than unirradiated virus, even in unirradiated cells; (4) cell irradiation did not change the mutagenesis of irradiated virus except at high multiplicity of infection. High multiplicity of infection did not demonstrate UVER or MR alone to be either error-free or error-prone. When the two processes were present simultaneously, they were mutagenic. (orig.)

  11. Impact of host cell line adaptation on quasispecies composition and glycosylation of influenza A virus hemagglutinin.

    Directory of Open Access Journals (Sweden)

    Jana Verena Roedig

    Full Text Available The genome of influenza A viruses is constantly changing (genetic drift resulting in small, gradual changes in viral proteins. Alterations within antibody recognition sites of the viral membrane glycoproteins hemagglutinin (HA and neuraminidase (NA result in an antigenetic drift, which requires the seasonal update of human influenza virus vaccines. Generally, virus adaptation is necessary to obtain sufficiently high virus yields in cell culture-derived vaccine manufacturing. In this study detailed HA N-glycosylation pattern analysis was combined with in-depth pyrosequencing analysis of the virus genomic RNA. Forward and backward adaptation from Madin-Darby Canine Kidney (MDCK cells to African green monkey kidney (Vero cells was investigated for two closely related influenza A virus PR/8/34 (H1N1 strains: from the National Institute for Biological Standards and Control (NIBSC or the Robert Koch Institute (RKI. Furthermore, stability of HA N-glycosylation patterns over ten consecutive passages and different harvest time points is demonstrated. Adaptation to Vero cells finally allowed efficient influenza A virus replication in Vero cells. In contrast, during back-adaptation the virus replicated well from the very beginning. HA N-glycosylation patterns were cell line dependent and stabilized fast within one (NIBSC-derived virus or two (RKI-derived virus successive passages during adaptation processes. However, during adaptation new virus variants were detected. These variants carried "rescue" mutations on the genomic level within the HA stem region, which result in amino acid substitutions. These substitutions finally allowed sufficient virus replication in the new host system. According to adaptation pressure the composition of the virus populations varied. In Vero cells a selection for "rescue" variants was characteristic. After back-adaptation to MDCK cells some variants persisted at indifferent frequencies, others slowly diminished and even

  12. Evidences Suggesting Involvement of Viruses in Oral Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Kanupriya Gupta

    2013-01-01

    Full Text Available Oral cancer is one of the most common cancers and it constitutes a major health problem particularly in developing countries. Oral squamous cell carcinoma (OSCC represents the most frequent of all oral neoplasms. Several risk factors have been well characterized to be associated with OSCC with substantial evidences. The etiology of OSCC is complex and involves many factors. The most clearly defined potential factors are smoking and alcohol, which substantially increase the risk of OSCC. However, despite this clear association, a substantial proportion of patients develop OSCC without exposure to them, emphasizing the role of other risk factors such as genetic susceptibility and oncogenic viruses. Some viruses are strongly associated with OSCC while the association of others is less frequent and may depend on cofactors for their carcinogenic effects. Therefore, the exact role of viruses must be evaluated with care in order to improve the diagnosis and treatment of OSCC. Although a viral association within a subset of OSCC has been shown, the molecular and histopathological characteristics of these tumors have yet to be clearly defined.

  13. Simian immunodeficiency virus interactions with macaque dendritic cells.

    Science.gov (United States)

    Teleshova, Natalia; Derby, Nina; Martinelli, Elena; Pugach, Pavel; Calenda, Giulia; Robbiani, Melissa

    2013-01-01

    This chapter summarizes advances in the following areas: (1) dendritic cell (DC)-mediated simian immunodeficiency virus (SIV) transmission, (2) role of DCs in innate and adaptive immunity against SIV, and (3) approaches to harness DC function to induce anti-SIV responses. The nonhuman primate (NHP) model of human immunodeficiency virus (HIV) infection in rhesus macaques and other Asian NHP species is highly relevant to advance the understanding of virus-host interactions critical for transmission and disease pathogenesis. HIV infection is associated with changes in frequency, phenotype, and function of the two principal subsets of DCs, myeloid DCs and plasmacytoid DCs. DC biology during pathogenic SIV infection is strikingly similar to that observed in HIV-infected patients. The NHP models provide an opportunity to dissect the requirements for DC-driven SIV infection and to understand how SIV distorts the DC system to its advantage. Furthermore, the SIV model of mucosal transmission enables the study of the earliest events of infection at the portal of entry that cannot be studied in humans, and, importantly, the involvement of DCs. Nonpathogenic infection in African NHP hosts allows investigations into the role of DCs in disease control. Understanding how DCs are altered during SIV infection is critical to the design of therapeutic and preventative strategies against HIV. PMID:22975875

  14. Insertions in the gG Gene of Pseudorabies Virus Reduce Expression of the Upstream Us3 Protein and Inhibit Cell-to-Cell Spread of Virus Infection

    OpenAIRE

    Demmin, Gretchen L.; Clase, Amanda C.; Randall, Jessica A.; Enquist, L W; Banfield, Bruce W.

    2001-01-01

    The alphaherpesvirus Us4 gene encodes glycoprotein G (gG), which is conserved in most viruses of the alphaherpesvirus subfamily. In the swine pathogen pseudorabies virus (PRV), mutant viruses with internal deletions and insertions in the gG gene have shown no discernible phenotypes. We report that insertions in the gG locus of the attenuated PRV strain Bartha show reduced virulence in vivo and are defective in their ability to spread from cell to cell in a cell-type-specific manner. Similar i...

  15. MEK kinase 1 is a negative regulator of virus-specific CD8(+) T cells

    DEFF Research Database (Denmark)

    Labuda, Tord; Christensen, Jan Pravsgaard; Rasmussen, Susanne; Bonnesen, Barbara; Karin, Michael; Thomsen, Allan Randrup; Ødum, Niels

    2006-01-01

    in the generation of a virus-specific immune response. Mekk1(DeltaKD) mice challenged with vesicular stomatitis virus (VSV) showed a fourfold increase in splenic CD8(+) T cell numbers. In contrast, the number of splenic T cells in infected WT mice was only marginally increased. The CD8(+) T cell...... result of increased proliferation, since a significantly higher percentage of virus-specific Mekk1(DeltaKD) CD8(+) T cells incorporated BrdU as compared to virus-specific WT CD8(+) T cells. In contrast, similar levels of apoptosis were detected in Mekk1(DeltaKD) and WT T cells following VSV infection....... These results strongly suggest that MEKK1 plays a negative regulatory role in the expansion of virus-specific CD8(+) T cells in vivo....

  16. Recent Advances in Hepatitis C Virus Cell Entry

    Directory of Open Access Journals (Sweden)

    Jean Dubuisson

    2010-03-01

    Full Text Available More than 170 million patients worldwide are chronically infected with hepatitis C virus (HCV. Prevalence rates range from 0.5% in Northern European countries to 28% in some areas of Egypt. HCV is hepatotropic, and in many countries chronic hepatitis C is a leading cause of liver disease including fibrosis, cirrhosis and hepatocellular carcinoma. HCV persists in 50–85% of infected patients, and once chronic infection is established, spontaneous clearance is rare. HCV is a member of the Flaviviridae family, in which it forms its own genus. Many lines of evidence suggest that the HCV life cycle displays many differences to that of other Flaviviridae family members. Some of these differences may be due to the close interaction of HCV with its host’s lipid and particular triglyceride metabolism in the liver, which may explain why the virus can be found in association with lipoproteins in serum of infected patients. This review focuses on the molecular events underlying the HCV cell entry process and the respective roles of cellular co-factors that have been implied in these events. These include, among others, the lipoprotein receptors low density lipoprotein receptor and scavenger receptor BI, the tight junction factors occludin and claudin-1 as well as the tetraspanin CD81. We discuss the roles of these cellular factors in HCV cell entry and how association of HCV with lipoproteins may modulate the cell entry process.

  17. HTLV-1: ancient virus, new challenges

    OpenAIRE

    Marzieh Rahimzadegan; Farshid Abedi; Seyed Abodolrahim Rezaei; Reza Ghadimi

    2014-01-01

    Human T-lymphotropic virus (HTLV-1) is an ancient pathogen for human being but arising and recognized recently. The routes of transmission are vertical (mainly by breastfeeding), unsafe sexual contacts and through contaminated blood components specially in whom need frequent and repeated blood transfusions such as permanent anemia due to blood loss in hemophilia and major thalassemia. Patients who should undergo hemodialysis in their lifelong are another instance for increased risk of HTLV-1 ...

  18. Characterization of Ebola Virus Entry by Using Pseudotyped Viruses: Identification of Receptor-Deficient Cell Lines

    OpenAIRE

    Wool-Lewis, Rouven J.; Bates, Paul

    1998-01-01

    Studies analyzing Ebola virus replication have been severely hampered by the extreme pathogenicity of this virus. To permit analysis of the host range and function of the Ebola virus glycoprotein (Ebo-GP), we have developed a system for pseudotyping these glycoproteins into murine leukemia virus (MLV). This pseudotyped virus, MLV(Ebola), can be readily concentrated to titers which exceed 5 × 106 infectious units/ml and is effectively neutralized by antibodies specific for Ebo-GP. Analysis of ...

  19. Herpes simplex virus type-1 and human lymphocytes: virus expression and the response to infection of adult and foetal cells

    International Nuclear Information System (INIS)

    The growth of Herpes simplex virus type 1 (HSV-1) in human lymphocytes of adult and foetal origin was studied. Virus DNA synthesis, antigen and particle production and the yield of infectious progeny were determined in cultured lymphocytes with or without exposure to stimulating concentrations of the mitogen phytohaemagglutinin and pokeweed mitogen. Separated subpopulations of cells were examined and the conclusion reached that only the stimulated T-lymphoblast was permissive for full virus expression. Stimulation of cell DNA synthesis in response to infection was observed in cultures of adult and foetal lymphocytes under conditions which were non-permissive for virus growth. Morphological change and prolonged culture survival were a feature of foetal lymphocytes exposed to u.v. irradiated HSV-1. (author)

  20. Modelling the Impact of Cell-To-Cell Transmission in Hepatitis B Virus.

    Science.gov (United States)

    Goyal, Ashish; Murray, John M

    2016-01-01

    Cell-free virus is a well-recognized and efficient mechanism for the spread of hepatitis B virus (HBV) infection in the liver. Cell-to-cell transmission (CCT) can be a more efficient means of virus propagation. Despite experimental evidence implying CCT occurs in HBV, its relative impact is uncertain. We develop a 3-D agent-based model where each hepatocyte changes its viral state according to a dynamical process driven by cell-free virus infection, CCT and intracellular replication. We determine the relative importance of CCT in the development and resolution of acute HBV infection in the presence of cytolytic (CTL) and non-CTL mechanisms. T cell clearance number is defined as the minimum number of infected cells needed to be killed by each T cell at peak infection that results in infection clearance within 12 weeks with hepatocyte turnover (HT, number of equivalent livers) ≤3. We find that CCT has very little impact on the establishment of infection as the mean cccDNA copies/cell remains between 15 to 20 at the peak of the infection regardless of CCT strength. In contrast, CCT inhibit immune-mediated clearance of acute HBV infection as higher CCT strength requires higher T cell clearance number and increases the probability of T cell exhaustion. An effective non-CTL inhibition can counter these negative effects of higher strengths of CCT by supporting rapid, efficient viral clearance and with little liver destruction. This is evident as the T cell clearance number drops by approximately 50% when non-CTL inhibition is increased from 10% to 80%. Higher CCT strength also increases the probability of the incidence of fulminant hepatitis with this phenomenon being unlikely to arise for no CCT. In conclusion, we report the possibility of CCT impacting HBV clearance and its contribution to fulminant hepatitis. PMID:27560827

  1. Reconstitution of hepatitis B virus (HBV)-specific T cell responses with treatment of human immunodeficiency virus/HBV coinfection

    OpenAIRE

    Lascar, R. M.; Gilson, R. J.; Lopes, A. R.; Bertoletti, A.; Maini, M K

    2003-01-01

    Liver-related mortality is an increasing problem in human immunodeficiency virus (HIV)/hepatitis B virus (HBV)-coinfected patients receiving highly active antiretroviral therapy (HAART). In HIV-negative patients, HBV chronicity is associated with a reduction in specific T cell responses that can be partially restored by treatment with lamivudine. We studied 5 HIV/HBV-coinfected patients treated with HAART, either with or without addition of a drug with specific anti-HBV activity. Our data sho...

  2. Feline immunodeficiency virus infection.

    Science.gov (United States)

    Pedersen, N C; Yamamoto, J K; Ishida, T; Hansen, H

    1989-05-01

    Feline immunodeficiency virus (FIV) (formerly feline T-lymphotropic lentivirus or FTLV) was first isolated from a group of cats in Petaluma, California in 1986. The virus is a typical lentivirus in gross and structural morphology. It replicates preferentially but not exclusively in feline T-lymphoblastoid cells, where it causes a characteristic cytopathic effect. The major structural proteins are 10, 17 (small gag), 28 (major core), 31 (endonuclease?), 41 (transmembrane?), 52 (core precursor polyprotein), 54/62 (reverse transcriptase?), and 110/130 (major envelope) kilodaltons in size. The various proteins are antigenically distinguishable from those of other lentiviruses, although serum from EIAV-infected horses will cross-react with some FIV antigens. Kittens experimentally infected with FIV manifest a transient (several days to 2 weeks) fever and neutropenia beginning 4 to 8 weeks after inoculation. This is associated with a generalized lymphadenopathy that persists for up to 9 months. Most cats recover from this initial phase of the disease and become lifelong carriers of the virus. Complete recovery does not occur to any extent in nature or in the laboratory setting. One experimentally infected cat died from a myeloproliferative disorder several months after infection. The terminal AIDS-like phase of the illness has been seen mainly in naturally infected cats. It appears a year or more following the initial infection in an unknown proportion of infected animals. FIV has been identified in cats from all parts of the world. It is most prevalent in high density populations of free roaming cats (feral and pet), and is very uncommon in closed purebred catteries. Male cats are twice as likely to become infected as females. Older male cats adopted as feral or stray animals are at the highest risk of infection, therefore. The infection rate among freely roaming cats rises throughout life, and reaches levels ranging from less than 1% to 12% or more depending on the

  3. Effect of caffeine on induction of endogenous type C virus in mouse cells in vitro

    International Nuclear Information System (INIS)

    The effect of caffeine on the expression of murine endogenous virus in mouse cells induced by radiation and chemicals was studied. Postirradiation treatment of K-BALB cells with caffeine enhanced cell killing as well as the induction of xenotropic virus after ultraviolet light irradiation. The degree of enhancement for the virus induction was comparable to that for cell killing. On the other hand, colony-forming ability and the expression of xenotropic virus of K-BALB cells after X-irradiation were unaffected by caffeine. These data suggest a linear relationship between the degree of endogenous virus expression and the amount of lethal damages after irradiation. For induction by halogenated pyrimidines, a 24-hr incubation of AKR2B cells with caffeine after 5-iodo-2'-deoxyuridine treatment resulted in marked suppression of the expression of ecotropic virus. On the contrary, in K-BALB cells, caffeine exerted only a small effect on 5-iodo-2'-deoxyuridine-induced expression of ecotropic and xenotropic viruses. These results indicate that, although using the same inducing agent, the pathway of endogenous virus induction may be different for AKR2B cells and for K-BALB cells

  4. Ultraviolet reactivation of herpes simplex virus in mutagenic and inducible in mammalian cells

    International Nuclear Information System (INIS)

    The survival of uv-irradiated herpes simplex virus on uv-irradiated Vero cells was increased over that on unirradiated cells. A time period between irradiation of the host cells and infection with virus was needed to achieve maximum reactivation. In parallel experiments in which the frequencies of occurrence of the forward mutation in the thymidine kinase gene of the virus were measured, growth of herpes simplex virus on uv-irradiated cells yielded progeny virus that had higher frequencies of TK- mutants than did progeny from infections of control cells. The time course of development of this mutagenic effect was the same as that for the development of the uv-reactivation capacity. Furthermore, development of the uv reactivation could be blocked by inhibition of protein synthesis. These results suggest that an ''error-prone'' inducible uv-reactivation phenomenon exists in mammalian cells

  5. Inflammatory infiltration of the upper airway epithelium during Sendai virus infection: involvement of epithelial dendritic cells.

    OpenAIRE

    McWilliam, A S; Marsh, A.M.; Holt, P G

    1997-01-01

    We undertook the present study to determine the nature of the cellular inflammatory response within the epithelial lining of the rat trachea during a Sendai virus infection. In particular, we aimed to investigate changes in the resident population of epithelial dendritic cells. Rats were infected with Sendai virus, and tracheal tissue was examined immunohistochemically at various times with a panel of cell-specific monoclonal antibodies. We found that Sendai virus infection was restricted to ...

  6. Stringent chemical and thermal regulation of recombinant gene expression by vaccinia virus vectors in mammalian cells.

    OpenAIRE

    Ward, G. A.; Stover, C. K.; B. Moss; Fuerst, T R

    1995-01-01

    We developed a stringently regulated expression system for mammalian cells that uses (i) the RNA polymerase, phi 10 promoter, and T phi transcriptional terminator of bacteriophage T7; (ii) the lac repressor, lac operator, rho-independent transcriptional terminators and the gpt gene of Escherichia coli; (iii) the RNA translational enhancer of encephalomyocarditis virus; and (iv) the genetic background of vaccinia virus. In cells infected with the recombinant vaccinia virus, reporter beta-galac...

  7. The receptors for gibbon ape leukemia virus and amphotropic murine leukemia virus are not downregulated in productively infected cells

    Directory of Open Access Journals (Sweden)

    Eiden Maribeth V

    2011-07-01

    Full Text Available Abstract Background Over the last several decades it has been noted, using a variety of different methods, that cells infected by a specific gammaretrovirus are resistant to infection by other retroviruses that employ the same receptor; a phenomenon termed receptor interference. Receptor masking is thought to provide an earlier means of blocking superinfection, whereas receptor down regulation is generally considered to occur in chronically infected cells. Results We used replication-competent GFP-expressing viruses containing either an amphotropic murine leukemia virus (A-MLV or the gibbon ape leukemia virus (GALV envelope. We also constructed similar viruses containing fluorescence-labeled Gag proteins for the detection of viral particles. Using this repertoire of reagents together with a wide range of antibodies, we were able to determine the presence and availability of viral receptors, and detect viral envelope proteins and particles presence on the cell surface of chronically infected cells. Conclusions A-MLV or GALV receptors remain on the surface of chronically infected cells and are detectable by respective antibodies, indicating that these receptors are not downregulated in these infected cells as previously proposed. We were also able to detect viral envelope proteins on the infected cell surface and infected cells are unable to bind soluble A-MLV or GALV envelopes indicating that receptor binding sites are masked by endogenously expressed A-MLV or GALV viral envelope. However, receptor masking does not completely prevent A-MLV or GALV superinfection.

  8. Monitoring for Presence of Potentially Xenotic Viruses in Recipients of Pig Islet Xenotransplantation

    OpenAIRE

    Garkavenko, O.; Croxson, M C; Irgang, M.; Karlas, A.; Denner, J; Elliott, R B

    2004-01-01

    This study represents a long-term follow-up of human patients receiving pig islet xenotransplantation. Eighteen patients had been monitored for up to 9 years for potentially xenotic pig viruses: pig endogenous retrovirus, pig cytomegalovirus, pig lymphotropic herpesvirus, and pig circovirus type 2. No evidence of viral infection was found.

  9. MUC1 in human milk blocks transmission of human immunodeficiency virus from dendritic cells to T cells

    NARCIS (Netherlands)

    Saeland, E.; Jong, de M.A.W.P.; Nabatov, A.; Kalay, H.; Kooijk, van Y.; Geijtenbeek, T.B.H.

    2009-01-01

    Mother-to-child transmission of human immunodeficiency virus-1 (HIV-1) occurs frequently via breast-feeding. HIV-1 targets DC-SIGN+ dendritic cells (DCs) in mucosal areas that allow efficient transmission of the virus to T cells. Here, we demonstrate that the epithelial mucin MUC1, abundant in milk,

  10. Effect of the infectious laryngotracheitis virus (ILTV) glycoprotein G on virus attachment, penetration, growth curve and direct cell-to-cell spread

    Institute of Scientific and Technical Information of China (English)

    SUN; Zhaogang; ZHANG; Manfu

    2005-01-01

    The secreted alphaherpesvirus glycoprotein G (gG) works differently from other proteins. Analysis of the role of ILTV gG in virus attachment, penetration, direct cell-to-cell spread (CTCS) and the growth curve showed that gG or its antibody had no effect on ILTV attachment and penetration and that the gG antibody reduced the virus plaque size and the one-step growth curve on chicken embryo liver (CEL) cells, but gG did not affect the virus plaque size or the one-step growth curve on CEL cells. Laser scanning confocal microscopy (LSCM) detection showed that ILTV gG is located in the perinuclear region and the membrane of the CEL cells. These results suggested that ILTV gG might contribute to direct cell-to-cell transmission.

  11. Influenza virus assays based on virus‐inducible reporter cell lines

    Science.gov (United States)

    Li, Yunsheng; Larrimer, Audrey; Curtiss, Teresa; Kim, Jaekyung; Jones, Abby; Baird‐Tomlinson, Heather; Pekosz, Andrew; Olivo, Paul D.

    2009-01-01

    Background  Virus‐inducible reporter genes have been used as the basis of virus detection and quantitation assays for a number of viruses. A strategy for influenza A virus‐induction of a reporter gene was recently described. In this report, we describe the extension of this strategy to influenza B virus, the generation of stable cell lines with influenza A and B virus‐inducible reporter genes, and the use of these cells in various clinically relevant viral assays. Each of the cell lines described herein constitutively express an RNA transcript that contains a reporter gene coding region flanked by viral 5′‐ and 3′‐untranslated regions (UTR) and therefore mimics an influenza virus genomic segment. Upon infection of the cells with influenza virus the virus‐inducible reporter gene segment (VIRGS) is replicated and transcribed by the viral polymerase complex resulting in reporter gene expression. Findings  Reporter gene induction occurs after infection with a number of laboratory strains and clinical isolates of influenza virus including several H5N1 strains. The induction is dose‐dependent and highly specific for influenza A or influenza B viruses. Conclusions  These cell lines provide the basis of simple, rapid, and objective assays that involve virus quantitation such as determination of viral titer, assessment of antiviral susceptibility, and determination of antibody neutralization titer. These cell lines could be very useful for influenza virus researchers and vaccine manufacturers. PMID:21462401

  12. Dendritic cells in dengue virus infection: Targets of virus replication and mediators of immunity

    Directory of Open Access Journals (Sweden)

    Michael A. Schmid

    2014-12-01

    Full Text Available Dendritic cells (DCs are sentinels of the immune system and detect pathogens at sites of entry, such as the skin. In addition to the ability of DCs to control infections directly via their innate immune functions, DCs help to prime adaptive B and T cell responses via antigen presentation in lymphoid tissues. Infected Aedes aegypti or Ae. albopictus mosquitoes transmit the four dengue virus (DENV serotypes to humans while probing for small blood vessels in the skin. DENV causes the most prevalent arthropod-borne viral disease in humans, yet no vaccine or specific therapeutic is currently approved. Although primary DENV infection confers life-long protective immunity against re-infection with the same DENV serotype, secondary infection with a different DENV serotype can lead to increased disease severity via cross-reactive T cells or enhancing antibodies. This review summarizes recent findings in humans and animal models about DENV infection of DCs, monocytes and macrophages. We discuss the dual role of DCs as both targets of DENV replication and mediators of innate and adaptive immunity, and summarize immune evasion strategies whereby DENV impairs the function of infected DCs. We suggest that DCs play a key role in priming DENV-specific neutralizing or potentially harmful memory B and T cell responses, and that future DC-directed therapies may help induce protective memory responses and reduce dengue pathogenesis.

  13. Tomato spotted wilt virus glycoproteins exhibit trafficking and localization signals that are functional in mammalian cells

    NARCIS (Netherlands)

    Kikkert, M.; Verschoor, A.; Kormelink, R.; Rottier, P.; Goldbach, R.

    2001-01-01

    The glycoprotein precursor (G1/G2) gene of tomato spotted wilt virus (TSWV) was expressed in BHK cells using the Semliki Forest virus expression system. The results reveal that in this cell system, the precursor is efficiently cleaved and the resulting G1 and G2 glycoproteins are transported from th

  14. Detection of bluetongue virus by using bovine endothelial cells and embryonated chicken eggs.

    OpenAIRE

    Wechsler, S J; Luedke, A. J.

    1991-01-01

    Two systems, inoculation of bovine endothelial cells and of embryonated chicken eggs, were compared for detection of bluetongue virus (BTV) in blood specimens from experimentally inoculated sheep. For all BTV serotypes tested, embryonated chicken eggs detected longer periods of viremia than did bovine endothelial cells, primarily by detecting BTV in samples containing lower virus concentrations.

  15. The ex vivo purge of cancer cells using oncolytic viruses: recent advances and clinical implications

    Directory of Open Access Journals (Sweden)

    Tsang JJ

    2015-01-01

    Full Text Available Jovian J Tsang,1,2 Harold L Atkins2,3 1Department of Biochemistry, University of Ottawa, 2Cancer Therapeutics, Ottawa Hospital Research Institute, 3Blood and Marrow Transplant Program, The Ottawa Hospital, Ottawa, ON, Canada Abstract: Hematological malignancies are treated with intensive high-dose chemotherapy, with or without radiation. This is followed by hematopoietic stem cell (HSC transplantation (HSCT to rescue or reconstitute hematopoiesis damaged by the anticancer therapy. Autologous HSC grafts may contain cancer cells and purging could further improve treatment outcomes. Similarly, allogeneic HSCT may be improved by selectively purging alloreactive effector cells from the graft rather than wholesale immune cell depletion. Viral agents that selectively replicate in specific cell populations are being studied in experimental models of cancer and immunological diseases and have potential applications in the context of HSC graft engineering. This review describes preclinical studies involving oncolytic virus strains of adenovirus, herpes simplex virus type 1, myxoma virus, and reovirus as ex vivo purging agents for HSC grafts, as well as in vitro and in vivo experimental studies using oncolytic coxsackievirus, measles virus, parvovirus, vaccinia virus, and vesicular stomatitis virus to eradicate hematopoietic malignancies. Alternative ex vivo oncolytic virus strategies are also outlined that aim to reduce the risk of relapse following autologous HSCT and mitigate morbidity and mortality due to graft-versus-host disease in allogeneic HSCT. Keywords: hematopoietic stem cells, oncolytic virus, hematopoietic stem cell transplantation, stem cell graft purging, hematopoietic malignancy, graft vs host disease

  16. HCMV spread and cell tropism are determined by distinct virus populations.

    Directory of Open Access Journals (Sweden)

    Laura Scrivano

    Full Text Available Human cytomegalovirus (HCMV can infect many different cell types in vivo. Two gH/gL complexes are used for entry into cells. gH/gL/pUL(128,130,131A shows no selectivity for its host cell, whereas formation of a gH/gL/gO complex only restricts the tropism mainly to fibroblasts. Here, we describe that depending on the cell type in which virus replication takes place, virus carrying the gH/gL/pUL(128,130,131A complex is either released or retained cell-associated. We observed that virus spread in fibroblast cultures was predominantly supernatant-driven, whereas spread in endothelial cell (EC cultures was predominantly focal. This was due to properties of virus released from fibroblasts and EC. Fibroblasts released virus which could infect both fibroblasts and EC. In contrast, EC released virus which readily infected fibroblasts, but was barely able to infect EC. The EC infection capacities of virus released from fibroblasts or EC correlated with respectively high or low amounts of gH/gL/pUL(128,130,131A in virus particles. Moreover, we found that focal spread in EC cultures could be attributed to EC-tropic virus tightly associated with EC and not released into the supernatant. Preincubation of fibroblast-derived virus progeny with EC or beads coated with pUL131A-specific antibodies depleted the fraction that could infect EC, and left a fraction that could predominantly infect fibroblasts. These data strongly suggest that HCMV progeny is composed of distinct virus populations. EC specifically retain the EC-tropic population, whereas fibroblasts release EC-tropic and non EC-tropic virus. Our findings offer completely new views on how HCMV spread may be controlled by its host cells.

  17. Inhibition of Mayaro virus replication by cerulenin in Aedes albopictus cells

    International Nuclear Information System (INIS)

    The antibiotic cerulenin, an inhibitor of lipid synthesis, was shown to suppress Mayaro virus replication in Aedes albopictus cells at non-cytotoxic doses. Cerulenin blocked the incorporation of [3H]glycerol into lipids when present at anytime post infection. Cerulenin added at the beginning of infection inhibited the synthesis of virus proteins. However, when this antibiotic was added at later stages of infection, it had only a mild effect on the virus protein synthesis. The possibility that cerulenin acts by blocking an initial step in the Mayaro virus replication after virus entry and before late viral translation is discussed. (authors)

  18. Androgen-independent proliferation of LNCaP prostate cancer cells infected by xenotropic murine leukemia virus-related virus

    Energy Technology Data Exchange (ETDEWEB)

    Kakoki, Katsura [Division of Cytokine Signaling, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523 (Japan); Department of AIDS Research, Institute of Tropical Medicine, G-COE, Nagasaki University, Nagasaki 852-8523 (Japan); Department of Urology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523 (Japan); Kamiyama, Haruka [Division of Cytokine Signaling, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523 (Japan); Department of AIDS Research, Institute of Tropical Medicine, G-COE, Nagasaki University, Nagasaki 852-8523 (Japan); Izumida, Mai; Yashima, Yuka; Hayashi, Hideki [Division of Cytokine Signaling, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523 (Japan); Yamamoto, Naoki [Department of AIDS Research, Institute of Tropical Medicine, G-COE, Nagasaki University, Nagasaki 852-8523 (Japan); Department of Microbiology, National University of Singapore (Singapore); Matsuyama, Toshifumi [Division of Cytokine Signaling, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523 (Japan); Igawa, Tsukasa; Sakai, Hideki [Department of Urology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523 (Japan); Kubo, Yoshinao, E-mail: yoshinao@nagasaki-u.ac.jp [Division of Cytokine Signaling, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523 (Japan); Department of AIDS Research, Institute of Tropical Medicine, G-COE, Nagasaki University, Nagasaki 852-8523 (Japan)

    2014-04-25

    Highlights: • XMRV infection induces androgen-independent growth in LNCaP cells. • XMRV infection reduces expression of androgen receptor. • XMRV promotes appearance of androgen blocker-resistant prostate cancer cells. - Abstract: Xenotropic murine leukemia virus-related virus (XMRV) is a novel gammaretrovirus that was originally isolated from human prostate cancer. It is now believed that XMRV is not the etiologic agent of prostate cancer. An analysis of murine leukemia virus (MLV) infection in various human cell lines revealed that prostate cancer cell lines are preferentially infected by XMRV, and this suggested that XMRV infection may confer some sort of growth advantage to prostate cancer cell lines. To examine this hypothesis, androgen-dependent LNCaP cells were infected with XMRV and tested for changes in certain cell growth properties. We found that XMRV-infected LNCaP cells can proliferate in the absence of the androgen dihydrotestosterone. Moreover, androgen receptor expression is significantly reduced in XMRV-infected LNCaP cells. Such alterations were not observed in uninfected and amphotropic MLV-infected LNCaP cells. This finding explains why prostate cancer cell lines are preferentially infected with XMRV.

  19. Androgen-independent proliferation of LNCaP prostate cancer cells infected by xenotropic murine leukemia virus-related virus

    International Nuclear Information System (INIS)

    Highlights: • XMRV infection induces androgen-independent growth in LNCaP cells. • XMRV infection reduces expression of androgen receptor. • XMRV promotes appearance of androgen blocker-resistant prostate cancer cells. - Abstract: Xenotropic murine leukemia virus-related virus (XMRV) is a novel gammaretrovirus that was originally isolated from human prostate cancer. It is now believed that XMRV is not the etiologic agent of prostate cancer. An analysis of murine leukemia virus (MLV) infection in various human cell lines revealed that prostate cancer cell lines are preferentially infected by XMRV, and this suggested that XMRV infection may confer some sort of growth advantage to prostate cancer cell lines. To examine this hypothesis, androgen-dependent LNCaP cells were infected with XMRV and tested for changes in certain cell growth properties. We found that XMRV-infected LNCaP cells can proliferate in the absence of the androgen dihydrotestosterone. Moreover, androgen receptor expression is significantly reduced in XMRV-infected LNCaP cells. Such alterations were not observed in uninfected and amphotropic MLV-infected LNCaP cells. This finding explains why prostate cancer cell lines are preferentially infected with XMRV

  20. Analysis of the reduced growth factor dependency of simian virus 40-transformed 3T3 cells.

    OpenAIRE

    Powers, S; Fisher, P B; Pollack, R.

    1984-01-01

    We have measured in a defined serum-free medium the platelet-derived growth factor (PDGF) and insulin requirements of normal Swiss 3T3 cells, simian virus 40-transformed 3T3 cells, and partial revertants of simian virus 40-transformed 3T3 cells. Swiss 3T3 cells displayed strong requirements for both PDGF and insulin. Both of these requirements were significantly diminished in simian virus 40-transformed 3T3 cells. Analysis of the PDGF and insulin requirements of the revertants indicated that ...

  1. Expression of the infectious salmon anemia virus receptor on atlantic salmon endothelial cells correlates with the cell tropism of the virus.

    Science.gov (United States)

    Aamelfot, Maria; Dale, Ole Bendik; Weli, Simon Chioma; Koppang, Erling Olaf; Falk, Knut

    2012-10-01

    Infectious salmon anemia (ISA) is a World Organization for Animal Health (OIE)-listed disease of farmed Atlantic salmon, characterized by slowly developing anemia and circulatory disturbances. The disease is caused by ISA virus (ISAV) in the Orthomyxoviridae family; hence, it is related to influenza. Here we explore the pathogenesis of ISA by focusing on virus tropism, receptor tissue distribution, and pathological changes in experimentally and naturally infected Atlantic salmon. Using immunohistochemistry on ISAV-infected Atlantic salmon tissues with antibody to viral nucleoprotein, endotheliotropism was demonstrated. Endothelial cells lining the circulatory system were found to be infected, seemingly noncytolytic, and without vasculitis. No virus could be found in necrotic parenchymal cells. From endothelium, the virus budded apically and adsorbed to red blood cells (RBCs). No infection or replication within RBCs was detected, but hemophagocytosis was observed, possibly contributing to the severe anemia in fish with this disease. Similarly to what has been done in studies of influenza, we examined the pattern of virus attachment by using ISAV as a probe. Here we detected the preferred receptor of ISAV, 4-O-acetylated sialic acid (Neu4,5Ac(2)). To our knowledge, this is the first report demonstrating the in situ distribution of this sialic acid derivate. The pattern of virus attachment mirrored closely the distribution of infection, showing that the virus receptor is important for cell tropism, as well as for adsorption to RBCs. PMID:22811536

  2. The V domain of dog PVRL4 (nectin-4) mediates canine distemper virus entry and virus cell-to-cell spread

    International Nuclear Information System (INIS)

    The entry of canine distemper virus (CDV) is a multistep process that involves the attachment of CDV hemagglutinin (H) to its cellular receptor, followed by fusion between virus and cell membranes. Our laboratory recently identified PVRL4 (nectin-4) to be the epithelial receptor for measles and canine distemper viruses. In this study, we demonstrate that the V domain of PVRL4 is critical for CDV entry and virus cell-to-cell spread. Furthermore, four key amino acid residues within the V domain of dog PVRL4 and two within the CDV hemagglutinin were shown to be essential for receptor-mediated virus entry. - Highlights: • PVRL4 (nectin-4) is the epithelial cell receptor for measles and canine distemper viruses. • V domain of PVRL4 is critical for CDV entry, cell-to-cell spread, and syncytia formation. • Chimeric PVRL1 backbone substituted with the V domain of PVRL4 can function as a receptor. • Amino acids (F132/P133/A134/G135) within the V domain are essential for PVRL4 receptor activity. • Amino acids (P493/Y539) within CDV H protein are essential for PVRL4 receptor interaction

  3. The V domain of dog PVRL4 (nectin-4) mediates canine distemper virus entry and virus cell-to-cell spread

    Energy Technology Data Exchange (ETDEWEB)

    Delpeut, Sebastien; Noyce, Ryan S. [The Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5 (Canada); IWK Health Centre, Canadian Center for Vaccinology, Goldbloom Pavilion, Halifax, Nova Scotia, Canada B3H 1X5 (Canada); Richardson, Christopher D., E-mail: chris.richardson@dal.ca [The Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 1X5 (Canada); IWK Health Centre, Canadian Center for Vaccinology, Goldbloom Pavilion, Halifax, Nova Scotia, Canada B3H 1X5 (Canada); The Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia (Canada)

    2014-04-15

    The entry of canine distemper virus (CDV) is a multistep process that involves the attachment of CDV hemagglutinin (H) to its cellular receptor, followed by fusion between virus and cell membranes. Our laboratory recently identified PVRL4 (nectin-4) to be the epithelial receptor for measles and canine distemper viruses. In this study, we demonstrate that the V domain of PVRL4 is critical for CDV entry and virus cell-to-cell spread. Furthermore, four key amino acid residues within the V domain of dog PVRL4 and two within the CDV hemagglutinin were shown to be essential for receptor-mediated virus entry. - Highlights: • PVRL4 (nectin-4) is the epithelial cell receptor for measles and canine distemper viruses. • V domain of PVRL4 is critical for CDV entry, cell-to-cell spread, and syncytia formation. • Chimeric PVRL1 backbone substituted with the V domain of PVRL4 can function as a receptor. • Amino acids (F132/P133/A134/G135) within the V domain are essential for PVRL4 receptor activity. • Amino acids (P493/Y539) within CDV H protein are essential for PVRL4 receptor interaction.

  4. Feline immunodeficiency virus decreases cell-cell communication and mitochondrial membrane potential.

    OpenAIRE

    Danave, I R; Tiffany-Castiglioni, E; Zenger, E; Barhoumi, R.; Burghardt, R C; Collisson, E W

    1994-01-01

    The in vitro effects of viral replication on mitochondrial membrane potential (MMP) and gap junctional intercellular communication (GJIC) were evaluated as two parameters of potential cellular injury. Two distinct cell types were infected with the Petaluma strain of feline immunodeficiency virus (FIV). Primary astroglia supported acute FIV infection, resulting in syncytia within 3 days of infection, whereas immortalized Crandell feline kidney (CRFK) cells of epithelial origin supported persis...

  5. Human T cell leukemia virus type 1 infection drives spontaneous proliferation of natural killer cells

    OpenAIRE

    Norris, Philip J; Hirschkorn, Dale F.; DeVita, Deborah A.; Lee, Tzong-Hae; Murphy, Eedward L

    2010-01-01

    Most human T cell leukemia virus type 1 (HTLV-1) infected subjects remain asymptomatic throughout their lives, with a few individuals developing HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) or adult T cell leukemia. Lymphocytes from about half of HTLV-1 infected subjects spontaneously proliferate in vitro, and how this phenomenon relates to symptomatic disease outcome and viral burden is poorly understood. Spontaneous proliferation was measured in lymphocyte subsets, an...

  6. Subcellular distribution of swine vesicular disease virus proteins and alterations induced in infected cells: A comparative study with foot-and-mouth disease virus and vesicular stomatitis virus

    International Nuclear Information System (INIS)

    The intracellular distribution of swine vesicular disease virus (SVDV) proteins and the induced reorganization of endomembranes in IBRS-2 cells were analyzed. Fluorescence to new SVDV capsids appeared first upon infection, concentrated in perinuclear circular structures and colocalized to dsRNA. As in foot-and-mouth disease virus (FMDV)-infected cells, a vesicular pattern was predominantly found in later stages of SVDV capsid morphogenesis that colocalized with those of non-structural proteins 2C, 2BC and 3A. These results suggest that assembly of capsid proteins is associated to the replication complex. Confocal microscopy showed a decreased fluorescence to ER markers (calreticulin and protein disulfide isomerase), and disorganization of cis-Golgi gp74 and trans-Golgi caveolin-1 markers in SVDV- and FMDV-, but not in vesicular stomatitis virus (VSV)-infected cells. Electron microscopy of SVDV-infected cells at an early stage of infection revealed fragmented ER cisternae with expanded lumen and accumulation of large Golgi vesicles, suggesting alterations of vesicle traffic through Golgi compartments. At this early stage, FMDV induced different patterns of ER fragmentation and Golgi alterations. At later stages of SVDV cytopathology, cells showed a completely vacuolated cytoplasm containing vesicles of different sizes. Cell treatment with brefeldin A, which disrupts the Golgi complex, reduced SVDV (∼ 5 log) and VSV (∼ 4 log) titers, but did not affect FMDV growth. Thus, three viruses, which share target tissues and clinical signs in natural hosts, induce different intracellular effects in cultured cells

  7. Nano-indentation experiments: from viruses to cells

    Science.gov (United States)

    Roos, Wouter; Vorselen, Daan; van Loon, Jack; Wuite, Gijs

    2012-02-01

    Over the last years AFM imaging and nanoindentation have become an indispensable tool for biophysical studies in liquid at the nano- and micro-scale. We look at both these length scales, at the cellular as well as the sub-cellular level. In particular, we perform combined imaging and force spectroscopy experiments on viral particles to elucidate their structure and mechanics [1]. These studies revealed that Noro virus has found an intriguing way to increase its mechanical strength. These self-assembling, natural nanoparticles incorporate a pre-stress during assembly, consolidating the structure of its protein shell that protects the genome [2]. Next, we studied whole cells. Mechanical loading is increasingly recognized as an important stimulus to cells. Establishing the local viscoelastic properties within a cell is vital to the understanding of the underlying mechanisms of cytoskeletal changes in response to these stimuli. We study the mechanical response of mammalian bone forming (osteoblast-like) cells on a substrate of physiological stiffness using spherical, μm-sized probes and we compare these results to the properties of bone forming cells originating from fish (teleosts).[4pt] [1] Roos et al. Nature Physics (2010), 6:733[0pt] [2] Baclayon et al. Nano Letters (2011), 11:4865

  8. Infectio: a Generic Framework for Computational Simulation of Virus Transmission between Cells

    Science.gov (United States)

    Yakimovich, Artur; Yakimovich, Yauhen; Schmid, Michael; Mercer, Jason; Sbalzarini, Ivo F.

    2016-01-01

    ABSTRACT Viruses spread between cells, tissues, and organisms by cell-free and cell-cell mechanisms, depending on the cell type, the nature of the virus, or the phase of the infection cycle. The mode of viral transmission has a large impact on disease development, the outcome of antiviral therapies or the efficacy of gene therapy protocols. The transmission mode of viruses can be addressed in tissue culture systems using live-cell imaging. Yet even in relatively simple cell cultures, the mechanisms of viral transmission are difficult to distinguish. Here we present a cross-platform software framework called “Infectio,” which is capable of simulating transmission phenotypes in tissue culture of virtually any virus. Infectio can estimate interdependent biological parameters, for example for vaccinia virus infection, and differentiate between cell-cell and cell-free virus spreading. Infectio assists in elucidating virus transmission mechanisms, a feature useful for designing strategies of perturbing or enhancing viral transmission. The complexity of the Infectio software is low compared to that of other software commonly used to quantitate features of cell biological images, which yields stable and relatively error-free output from Infectio. The software is open source (GPLv3 license), and operates on the major platforms (Windows, Mac, and Linux). The complete source code can be downloaded from http://infectio.github.io/index.html. IMPORTANCE Infectio presents a generalized platform to analyze virus infection spread between cells. It allows the simulation of plaque phenotypes from image-based assays. Viral plaques are the result of virus spreading from primary infected cells to neighboring cells. This is a complex process and involves neighborhood effects at cell-cell contact sites or fluid dynamics in the extracellular medium. Infectio differentiates between two major modes of virus transmission between cells, allowing in silico testing of hypotheses about

  9. Infectio: a Generic Framework for Computational Simulation of Virus Transmission between Cells.

    Science.gov (United States)

    Yakimovich, Artur; Yakimovich, Yauhen; Schmid, Michael; Mercer, Jason; Sbalzarini, Ivo F; Greber, Urs F

    2016-01-01

    Viruses spread between cells, tissues, and organisms by cell-free and cell-cell mechanisms, depending on the cell type, the nature of the virus, or the phase of the infection cycle. The mode of viral transmission has a large impact on disease development, the outcome of antiviral therapies or the efficacy of gene therapy protocols. The transmission mode of viruses can be addressed in tissue culture systems using live-cell imaging. Yet even in relatively simple cell cultures, the mechanisms of viral transmission are difficult to distinguish. Here we present a cross-platform software framework called "Infectio," which is capable of simulating transmission phenotypes in tissue culture of virtually any virus. Infectio can estimate interdependent biological parameters, for example for vaccinia virus infection, and differentiate between cell-cell and cell-free virus spreading. Infectio assists in elucidating virus transmission mechanisms, a feature useful for designing strategies of perturbing or enhancing viral transmission. The complexity of the Infectio software is low compared to that of other software commonly used to quantitate features of cell biological images, which yields stable and relatively error-free output from Infectio. The software is open source (GPLv3 license), and operates on the major platforms (Windows, Mac, and Linux). The complete source code can be downloaded from http://infectio.github.io/index.html. IMPORTANCE Infectio presents a generalized platform to analyze virus infection spread between cells. It allows the simulation of plaque phenotypes from image-based assays. Viral plaques are the result of virus spreading from primary infected cells to neighboring cells. This is a complex process and involves neighborhood effects at cell-cell contact sites or fluid dynamics in the extracellular medium. Infectio differentiates between two major modes of virus transmission between cells, allowing in silico testing of hypotheses about spreading

  10. Bat airway epithelial cells: a novel tool for the study of zoonotic viruses.

    Directory of Open Access Journals (Sweden)

    Isabella Eckerle

    Full Text Available Bats have been increasingly recognized as reservoir of important zoonotic viruses. However, until now many attempts to isolate bat-borne viruses in cell culture have been unsuccessful. Further, experimental studies on reservoir host species have been limited by the difficulty of rearing these species. The epithelium of the respiratory tract plays a central role during airborne transmission, as it is the first tissue encountered by viral particles. Although several cell lines from bats were established recently, no well-characterized, selectively cultured airway epithelial cells were available so far. Here, primary cells and immortalized cell lines from bats of the two important suborders Yangochiroptera and Yinpterochiroptera, Carollia perspicillata (Seba's short-tailed bat and Eidolon helvum (Straw-colored fruit bat, were successfully cultured under standardized conditions from both fresh and frozen organ specimens by cell outgrowth of organ explants and by the use of serum-free primary cell culture medium. Cells were immortalized to generate permanent cell lines. Cells were characterized for their epithelial properties such as expression of cytokeratin and tight junctions proteins and permissiveness for viral infection with Rift-Valley fever virus and vesicular stomatitis virus Indiana. These cells can serve as suitable models for the study of bat-borne viruses and complement cell culture models for virus infection in human airway epithelial cells.

  11. Identification of Contaminated Cells with Viruses, Bacteria, or Fungi by Fourier Transform Infrared Microspectroscopy

    OpenAIRE

    Erukhimovitch, V.; M. Huleihil; Huleihel, M.

    2013-01-01

    Fourier transform infrared microspectroscopy (FTIR-M) can detect small molecular changes in cells and therefore was previously applied for the identification of different biological samples. In the present study, FTIR spectroscopy was used for the identification and discrimination of Vero cells infected with herpes viruses or contaminated with bacteria or fungi in cell culture. Vero cells in culture were infected herpes simplex virus type 1 (HSV-1) or contaminated with E. coli bacteria or Can...

  12. Comparison of flow cytometry and virus isolation in cell culture for identification of cattle persistently infected with bovine viral diarrhea virus.

    OpenAIRE

    Qvist, P.; Houe, H.; Aasted, B.; Meyling, A

    1991-01-01

    Detection of bovine viral diarrhea virus in 143 blood samples by virus isolation in cell culture and flow cytometry was performed. The material included 37 samples later shown to originate from persistently infected cattle. Thirty-three samples were positive by virus isolation, and all 37 samples were positive by the flow cytometric assay.

  13. Virus and Bacterial Cell Chemical Analysis by NanoSIMS

    Energy Technology Data Exchange (ETDEWEB)

    Weber, P; Holt, J

    2008-07-28

    In past work for the Department of Homeland Security, the LLNL NanoSIMS team has succeeded in extracting quantitative elemental composition at sub-micron resolution from bacterial spores using nanometer-scale secondary ion mass spectrometry (NanoSIMS). The purpose of this task is to test our NanoSIMS capabilities on viruses and bacterial cells. This initial work has proven successful. We imaged Tobacco Mosaic Virus (TMV) and Bacillus anthracis Sterne cells using scanning electron microscopy (SEM) and then analyzed those samples by NanoSIMS. We were able resolve individual viral particles ({approx}18 nm by 300 nm) in the SEM and extract correlated elemental composition in the NanoSIMS. The phosphorous/carbon ratio observed in TMV is comparable to that seen in bacterial spores (0.033), as was the chlorine/carbon ratio (0.11). TMV elemental composition is consistent from spot to spot, and TMV is readily distinguished from debris by NanoSIMS analysis. Bacterial cells were readily identified in the SEM and relocated in the NanoSIMS for elemental analysis. The Ba Sterne cells were observed to have a measurably lower phosphorous/carbon ratio (0.005), as compared to the spores produced in the same run (0.02). The chlorine/carbon ratio was approximately 2.5X larger in the cells (0.2) versus the spores (0.08), while the fluorine/carbon ratio was approximately 10X lower in the cells (0.008) than the spores (0.08). Silicon/carbon ratios for both cells and spores encompassed a comparable range. The initial data in this study suggest that high resolution analysis is useful because it allows the target agent to be analyzed separate from particulates and other debris. High resolution analysis would also be useful for trace sample analysis. The next step in this work is to determine the potential utility of elemental signatures in these kinds of samples. We recommend bulk analyses of media and agent samples to determine the range of media compositions in use, and to determine how

  14. Differential proteome analysis of chikungunya virus infection on host cells.

    Directory of Open Access Journals (Sweden)

    Christina Li-Ping Thio

    Full Text Available BACKGROUND: Chikungunya virus (CHIKV is an emerging mosquito-borne alphavirus that has caused multiple unprecedented and re-emerging outbreaks in both tropical and temperate countries. Despite ongoing research efforts, the underlying factors involved in facilitating CHIKV replication during early infection remains ill-characterized. The present study serves to identify host proteins modulated in response to early CHIKV infection using a proteomics approach. METHODOLOGY AND PRINCIPAL FINDINGS: The whole cell proteome profiles of CHIKV-infected and mock control WRL-68 cells were compared and analyzed using two-dimensional gel electrophoresis (2-DGE. Fifty-three spots were found to be differentially modulated and 50 were successfully identified by MALDI-TOF/TOF. Eight were significantly up-regulated and 42 were down-regulated. The mRNA expressions of 15 genes were also found to correlate with the corresponding protein expression. STRING network analysis identified several biological processes to be affected, including mRNA processing, translation, energy production and cellular metabolism, ubiquitin-proteasome pathway (UPP and cell cycle regulation. CONCLUSION/SIGNIFICANCE: This study constitutes a first attempt to investigate alteration of the host cellular proteome during early CHIKV infection. Our proteomics data showed that during early infection, CHIKV affected the expression of proteins that are involved in mRNA processing, host metabolic machinery, UPP, and cyclin-dependent kinase 1 (CDK1 regulation (in favour of virus survival, replication and transmission. While results from this study complement the proteomics results obtained from previous late host response studies, functional characterization of these proteins is warranted to reinforce our understanding of their roles during early CHIKV infection in humans.

  15. Localization of West Nile Virus in monkey brain: double staining antigens immunohistochemically of neurons, neuroglia cells and West Nile Virus

    OpenAIRE

    He, Xianli; Ren, Junping; Xu, Fangling; Ferguson, Monique R; Li, Guangyu

    2009-01-01

    West Nile virus (WNV) can cause encephalitis or meningitis that affects brain tissue, which can also lead to permanent neurological damage that can be fatal. To our knowledge, no consistent double immunohistochemical staining of neurons, neuroglia cells, and WNV has yet been reported. To establish a method for performing double-label immunohistochemical detection of neurons, neuroglia cells and WNV, examining the pathological characteristics of WNV-infected neurons, neuroglia cells, and inves...

  16. Generation of a helper cell line for packaging avian leukosis virus-based vectors.

    OpenAIRE

    Savatier, P; Bagnis, C.; Thoraval, P; Poncet, D; Belakebi, M; Mallet, F.; Legras, C.; Cosset, F L; Thomas, J.L.; Chebloune, Y

    1989-01-01

    We constructed an avian leukosis virus-based packaging cell line, pHF-g, containing Rous-associated virus DNA with several alterations to abolish RNA packaging. One of them is a 52-base-pair deletion encompassing the putative encapsidation signal in the leader region. The 3' long terminal repeat was also removed and replaced by the polyadenylation sequence from the herpes simplex virus thymidine kinase gene. When pHF-g cells were transfected by an avian leukosis virus-based vector, they produ...

  17. Block to influenza virus replication in cells preirradiated with ultraviolet light

    International Nuclear Information System (INIS)

    Ultraviolet (uv) irradiation of CEF cells immediately before infection with influenza A (fowl plague) virus inhibited virus growth; no inhibition of the growth of a parainfluenza virus (Newcastle disease virus) could be detected in irradiated cells. The kinetics of inhibition after various doses of uv irradiation were multihit, with an extrapolation number of two. When irradiated cells were allowed to photoreactivate by exposure to visible light for 16 hr their capacity to support influenza virus replication was largely restored; this process was sensitive to caffeine, suggesting that it required DNA repair. In CEF cells exposed to 360 ergs/mm2 of uv radiation the rate of synthesis of host cellular RNA was reduced by more than 90%, and that of host cellular protein by 40 to 50%, as judged by incorporation of precursor molecules into an acid-insoluble form. When such irradiated cells were infected with influenza virus all the genome RNA segments were transcribed, but the overall concentration of virus-specific poly(A)-containing cRNA was reduced about 50-fold. Within this population of cRNA molecules, the RNAs coding for late proteins (HA, NA, and M) were reduced in amount relative to the other segments. The rates of synthesis of the M and HA proteins were specifically reduced in uv-irradiated cells, but the rates of synthesis of the P, NP, and NS proteins were only slightly reduced compared to normal cells. Immunofluorescent studies showed that, in uv-irradiated cells, NP migrated into the nucleus early after infection and later migrated out into the cytoplasm, as in normal cells. In contrast to normal cells, no specific immunofluorescence associated with M protein could be observed in uv-irradiated cells. It is concluded that uv-induced damage to host cellular DNA alters the pattern of RNA transcription in CEF cells infected with influenza virus, and that this results in a block to late protein synthesis which stops virus production

  18. Attachment of Sendai virus particles to cell membranes: dissociation of adsorbed virus particles with dithiothreitol.

    OpenAIRE

    Chejanovsky, N; Beigel, M; Loyter, A

    1984-01-01

    Sendai virus particles bind to human erythrocytes at 4 degrees C and fuse with them at 37 degrees C. The present work describes a new method by which adsorbed virus particles can be removed from human erythrocytes, allowing quantitative determination of the number of virus particles which can bind and fuse with human erythrocyte membranes. Through the use of 125I-labeled Sendai virus particles, it is shown that incubation with 50 mM dithiothreitol removed about 90 to 95% of adsorbed virus par...

  19. Vaccinia virus, herpes simplex virus, and carcinogens induce DNA amplification in a human cell line and support replication of a helpervirus dependent parvovirus

    International Nuclear Information System (INIS)

    The SV40-transformed human kidney cell line, NB-E, amplifies integrated as well as episomal SV40 DNA upon treatment with chemical (DMBA) or physical (uv irradiation) carcinogens (initiators) as well as after infection with herpes simplex virus (HSV) type 1 or with vaccinia virus. In addition it is shown that vaccinia virus induces SV40 DNA amplification also in the SV40-transformed Chinese hamster embryo cell line, CO631. These findings demonstrate that human cells similar to Chinese hamster cells amplify integrated DNA sequences after treatment with carcinogens or infection with specific viruses. Furthermore, a poxvirus--vaccinia virus--similar to herpes group viruses induces DNA amplification. As reported for other systems, the vaccinia virus-induced DNA amplification in NB-E cells is inhibited by coinfection with adeno-associated virus (AAV) type 5. This is in line with previous studies on inhibition of carcinogen- or HSV-induced DNA amplification in CO631 cells. The experiments also demonstrate that vaccinia virus, in addition to herpes and adenoviruses acts as a helper virus for replication and structural antigen synthesis of AAV-5 in NB-E cells

  20. Vaccinia virus, herpes simplex virus, and carcinogens induce DNA amplification in a human cell line and support replication of a helpervirus dependent parvovirus

    Energy Technology Data Exchange (ETDEWEB)

    Schlehofer, J.R.; Ehrbar, M.; zur Hausen, H.

    1986-07-15

    The SV40-transformed human kidney cell line, NB-E, amplifies integrated as well as episomal SV40 DNA upon treatment with chemical (DMBA) or physical (uv irradiation) carcinogens (initiators) as well as after infection with herpes simplex virus (HSV) type 1 or with vaccinia virus. In addition it is shown that vaccinia virus induces SV40 DNA amplification also in the SV40-transformed Chinese hamster embryo cell line, CO631. These findings demonstrate that human cells similar to Chinese hamster cells amplify integrated DNA sequences after treatment with carcinogens or infection with specific viruses. Furthermore, a poxvirus--vaccinia virus--similar to herpes group viruses induces DNA amplification. As reported for other systems, the vaccinia virus-induced DNA amplification in NB-E cells is inhibited by coinfection with adeno-associated virus (AAV) type 5. This is in line with previous studies on inhibition of carcinogen- or HSV-induced DNA amplification in CO631 cells. The experiments also demonstrate that vaccinia virus, in addition to herpes and adenoviruses acts as a helper virus for replication and structural antigen synthesis of AAV-5 in NB-E cells.

  1. Construction of cytopathic PK-15 cell model of classical swine fever virus

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    No cytopathic effect (CPE) can be observed on classical swine fever virus (CSFV) infected cell culture in vitro. This brings an obstacle to the researches on reciprocity between CSFV and host cells. Based on the construction of full-length genomic infectious Cdna clone of Chinese CSFV standard virulent Shimen strain, partial deletion is intro- duced into genomic Cdna to obtain a 7.5 kb subgenomic Cdna. A new subgenomic CSFV is derived from transfection with the subgenomic Cdna on PK-15 cells pre-infected by CSFV Shimen virus. Typical CPE induced by this subgenomic virus is observed on PK-15 cells. Coexistence of wild- type and subgenomic virus in cytopathic cell culture is dem- onstrated by RT-PCR detection in cytopathic cells. For conclusion, the construction of cytopathic cell model exploited a new way for researches on the molecular mechanism of CSFV pathogenesis.

  2. Avian Influenza Viruses, Inflammation, and CD8+ T Cell Immunity

    Science.gov (United States)

    Wang, Zhongfang; Loh, Liyen; Kedzierski, Lukasz; Kedzierska, Katherine

    2016-01-01

    Avian influenza viruses (AIVs) circulate naturally in wild aquatic birds, infect domestic poultry, and are capable of causing sporadic bird-to-human transmissions. AIVs capable of infecting humans include a highly pathogenic AIV H5N1, first detected in humans in 1997, and a low pathogenic AIV H7N9, reported in humans in 2013. Both H5N1 and H7N9 cause severe influenza disease in humans, manifested by acute respiratory distress syndrome, multi-organ failure, and high mortality rates of 60% and 35%, respectively. Ongoing circulation of H5N1 and H7N9 viruses in wild birds and poultry, and their ability to infect humans emphasizes their epidemic and pandemic potential and poses a public health threat. It is, thus, imperative to understand the host immune responses to the AIVs so we can control severe influenza disease caused by H5N1 or H7N9 and rationally design new immunotherapies and vaccines. This review summarizes our current knowledge on AIV epidemiology, disease symptoms, inflammatory processes underlying the AIV infection in humans, and recent studies on universal pre-existing CD8+ T cell immunity to AIVs. Immune responses driving the host recovery from AIV infection in patients hospitalized with severe influenza disease are also discussed. PMID:26973644

  3. Cell-specific targeting of lentiviral vectors mediated by fusion proteins derived from Sindbis virus, vesicular stomatitis virus, or avian sarcoma/leukosis virus

    OpenAIRE

    Marino Michael P; Bialkowska Agnieszka; Kutner Robert H; Zhang Xian-Yang; Klimstra William B; Reiser Jakob

    2010-01-01

    Abstract Background The ability to efficiently and selectively target gene delivery vectors to specific cell types in vitro and in vivo remains one of the formidable challenges in gene therapy. We pursued two different strategies to target lentiviral vector delivery to specific cell types. In one of the strategies, vector particles bearing a membrane-bound stem cell factor sequence plus a separate fusion protein based either on Sindbis virus strain TR339 glycoproteins or the vesicular stomati...

  4. Flow cytometric monitoring of influenza A virus infection in MDCK cells during vaccine production

    Directory of Open Access Journals (Sweden)

    Reichl Udo

    2008-04-01

    Full Text Available Abstract Background In cell culture-based influenza vaccine production the monitoring of virus titres and cell physiology during infection is of great importance for process characterisation and optimisation. While conventional virus quantification methods give only virus titres in the culture broth, data obtained by fluorescence labelling of intracellular virus proteins provide additional information on infection dynamics. Flow cytometry represents a valuable tool to investigate the influences of cultivation conditions and process variations on virus replication and virus yields. Results In this study, fluorescein-labelled monoclonal antibodies against influenza A virus matrix protein 1 and nucleoprotein were used for monitoring the infection status of adherent Madin-Darby canine kidney cells from bioreactor samples. Monoclonal antibody binding was shown for influenza A virus strains of different subtypes (H1N1, H1N2, H3N8 and host specificity (human, equine, swine. At high multiplicity of infection in a bioreactor, the onset of viral protein accumulation in adherent cells on microcarriers was detected at about 2 to 4 h post infection by flow cytometry. In contrast, a significant increase in titre by hemagglutination assay was detected at the earliest 4 to 6 h post infection. Conclusion It is shown that flow cytometry is a sensitive and robust method for the monitoring of viral infection in fixed cells from bioreactor samples. Therefore, it is a valuable addition to other detection methods of influenza virus infection such as immunotitration and RNA hybridisation. Thousands of individual cells are measured per sample. Thus, the presented method is believed to be quite independent of the concentration of infected cells (multiplicity of infection and total cell concentration in bioreactors. This allows to perform detailed studies on factors relevant for optimization of virus yields in cell cultures. The method could also be used for process

  5. Intracellular Transport of Plant Viruses: Finding the Door out of the Cell

    Institute of Scientific and Technical Information of China (English)

    James E. Schoelz; Phillip A. Harries; Richard S. Nelson

    2011-01-01

    Plant viruses are a class of plant pathogens that specialize in movement from cell to cell.As part of their arsenal for infection of plants,every virus encodes a movement protein (MP),a protein dedicated to enlarging the pore size of plasmodesmata (PD) and actively transporting the viral nucleic acid into the adjacent cell.As our knowledge of intercellular transport has increased,it has become apparent that viruses must also use an active mechanism to target the virus from their site of replication within the cell to the PD.Just as viruses are too large to fit through an unmodified plasmodesma,they are also too large to be freely diffused through the cytoplasm of the cell.Evidence has accumulated now for the involvement of other categories of viral proteins in intracellular movement in addition to the MP,including viral proteins originally associated with replication or gene expression.In this review,we will discuss the strategies that viruses use for intracellular movement from the replication site to the PD,in particular focusing on the role of host membranes for intracellular transport and the coordinated interactions between virus proteins within cells that are necessary for successful virus spread.

  6. Ebola Virus Failure to Stimulate Plasmacytoid Dendritic Cell Interferon Responses Correlates With Impaired Cellular Entry

    OpenAIRE

    Leung, Lawrence W.; Martinez, Osvaldo; Reynard, Olivier; Volchkov, Viktor E.; Basler, Christopher F.

    2011-01-01

    We examined the ability of the Ebola virus to elicit an antiviral response from plasmacytoid dendritic cells (pDCs). Exposure of pDCs to Ebola virus did not result in significantly higher levels of interferon-α production than the levels in mock-infected cells. After inoculation with Ebola virus under the same conditions, conventional dendritic cells expressed viral proteins whereas pDCs did not, suggesting that the latter cells were not infected. Assessment of the entry of Ebola virus–like p...

  7. Recognition of rabies and rabies-related viruses by T cells derived from human vaccine recipients.

    OpenAIRE

    Celis, E; Ou, D; Dietzschold, B.; Koprowski, H

    1988-01-01

    Human peripheral blood mononuclear cells and T-cell lines and clones from individuals immunized with rabies PM vaccine were tested for the ability to recognize antigenic determinants in rabies and rabies-related viruses in an antigen-induced proliferation assay. Some, but not all, of the T cells from these individuals cross-reacted with various laboratory strains of rabies virus with rabies-related viruses such as Duvenhage and Mokola. In addition, these T cells were shown to react with epito...

  8. Live Cell Reporter Systems for Positive-Sense Single Strand RNA Viruses.

    Science.gov (United States)

    Ren, Linzhu; Peng, Zhiyuan; Chen, Xinrong; Ouyang, Hongsheng

    2016-04-01

    Cell-based reporter systems have facilitated studies of viral replication and pathogenesis, virus detection, and drug susceptibility testing. There are three types of cell-based reporter systems that express certain reporter protein for positive-sense single strand RNA virus infections. The first type is classical reporter system, which relies on recombinant virus, reporter virus particle, or subgenomic replicon. During infection with the recombinant virus or reporter virus particle, the reporter protein is expressed and can be detected in real time in a dose-dependent manner. Using subgenomic replicon, which are genetically engineered viral RNA molecules that are capable of replication but incapable of producing virions, the translation and replication of the replicon could be tracked by the accumulation of reporter protein. The second type of reporter system involves genetically engineered cells bearing virus-specific protease cleavage sequences, which can sense the incoming viral protease. The third type is based on viral replicase, which can report the specific virus infection via detection of the incoming viral replicase. This review specifically focuses on the major technical breakthroughs in the design of cell-based reporter systems and the application of these systems to the further understanding and control of viruses over the past few decades. PMID:26728654

  9. BK virus-associated hemorrhagic cystitis after pediatric stem cell transplantation.

    Science.gov (United States)

    Han, Seung Beom; Cho, Bin; Kang, Jin Han

    2014-12-01

    Hemorrhagic cystitis is a common stem cell transplantation-related complication. The incidence of early-onset hemorrhagic cystitis, which is related to the pretransplant conditioning regimen, has decreased with the concomitant use of mesna and hyperhydration. However, late-onset hemorrhagic cystitis, which is usually caused by the BK virus, continues to develop. Although the BK virus is the most common pathogenic microorganism of poststem cell transplantation late-onset hemorrhagic cystitis, pediatricians outside the hemato-oncology and nephrology specialties tend to be unfamiliar with hemorrhagic cystitis and the BK virus. Moreover, no standard guidelines for the early diagnosis and treatment of BK virus-associated hemorrhagic cystitis after stem cell transplantation have been established. Here, we briefly introduce poststem cell transplantation BK virus-associated hemorrhagic cystitis. PMID:25653684

  10. Genistein inhibits the replication of avian leucosis virus subgroup J in DF-1 cells.

    Science.gov (United States)

    Qian, Kun; Gao, Ai-jun; Zhu, Ming-yue; Shao, Hong-xia; Jin, Wen-jie; Ye, Jian-qiang; Qin, Ai-jian

    2014-11-01

    To investigate the antiviral effects of genistein on the replication of avian leukosis virus subgroup J (ALV-J) in DF-1 cells, the cells were treated with genistein at different time points and the antiviral effects were examined by using a variety of assays. We determined that genistein strongly inhibited viral gene expression and decreased the viral protein level in the cell supernatant and the cytoplasm without alerting virus receptor expression and viral attachment. We also observed that genistein was not found to interfere with virus entry, but significantly inhibited both viral gene transcriptions at 24h post infection and virus release, which indicate that genistein exerts its inhibitory effects on the late phase of ALV-J replicative cycle. These results demonstrate that genistein effectively block ALV-J replication by inhibiting virus transcription and release in DF-1 cells, which may be useful for therapeutic drug design. PMID:25197039

  11. Japanese encephalitis virus disrupts cell-cell junctions and affects the epithelial permeability barrier functions.

    Directory of Open Access Journals (Sweden)

    Tanvi Agrawal

    Full Text Available Japanese encephalitis virus (JEV is a neurotropic flavivirus, which causes viral encephalitis leading to death in about 20-30% of severely-infected people. Although JEV is known to be a neurotropic virus its replication in non-neuronal cells in peripheral tissues is likely to play a key role in viral dissemination and pathogenesis. We have investigated the effect of JEV infection on cellular junctions in a number of non-neuronal cells. We show that JEV affects the permeability barrier functions in polarized epithelial cells at later stages of infection. The levels of some of the tight and adherens junction proteins were reduced in epithelial and endothelial cells and also in hepatocytes. Despite the induction of antiviral response, barrier disruption was not mediated by secreted factors from the infected cells. Localization of tight junction protein claudin-1 was severely perturbed in JEV-infected cells and claudin-1 partially colocalized with JEV in intracellular compartments and targeted for lysosomal degradation. Expression of JEV-capsid alone significantly affected the permeability barrier functions in these cells. Our results suggest that JEV infection modulates cellular junctions in non-neuronal cells and compromises the permeability barrier of epithelial and endothelial cells which may play a role in viral dissemination in peripheral tissues.

  12. The archetype enhancer of simian virus 40 DNA is duplicated during virus growth in human cells and rhesus monkey kidney cells but not in green monkey kidney cells

    International Nuclear Information System (INIS)

    Archetype SV40, obtained directly from its natural host, is characterized by a single 72-bp enhancer element. In contrast, SV40 grown in cell culture almost invariably exhibits partial or complete duplication of the enhancer region. This distinction has been considered important in studies of human tumor material, since SV40-associated tumor isolates have been described having a single enhancer region, suggesting natural infection as opposed to possible contamination by laboratory strains of virus. However, the behavior of archetypal SV40 in cultured cells has never been methodically studied. In this study we reengineered nonarchetypal 776-SV40 to contain a single 72-bp enhancer region and used this reengineered archetypal DNA to transfect a number of simian and human cell lines. SV40 DNA recovered from these cells was analyzed by restriction endonuclease analysis, PCR, and DNA sequencing. Reengineered archetype SV40 propagated in green monkey TC-7 or BSC-1 kidney cells remained without enhancer region duplication even after extensive serial virus passage. Archetype SV40 grown in all but one of the rhesus or human cell lines initially appeared exclusively archetypal. However, when virus from these cell types was transferred to green monkey cells, variants with partial enhancer duplication appeared after as little as a single passage. These findings suggest (1) that virus with a single 72-bp enhancer may persist in cultured cells of simian and human origin; (2) that variants with partially duplicated enhancer regions may arise within cell lines in quantities below limits of detection; (3) that these variants may enjoy a selective advantage in cell types other than those from which they arose (e.g., green monkey kidney cells); and (4) that certain cell lines may support a selective growth advantage for the variants without supporting their formation. Our data indicate that enhancer duplication may also occur in human as well as rhesus kidney cells. Thus, detection of

  13. Human cytotoxic T cells stimulated by antigen on dendritic cells recognize the N, SH, F, M, 22K, and 1b proteins of respiratory syncytial virus.

    OpenAIRE

    Cherrie, A H; Anderson, K.; Wertz, G W; Openshaw, P. J.

    1992-01-01

    We examined the human cytotoxic T-cell repertoire of nine adults to 9 of the 10 proteins of respiratory syncytial (RS) virus. Peripheral blood mononuclear cells from normal adults were stimulated with RS virus in vitro. The resulting polyclonal cultures were tested for lysis of B-lymphoblastoid cell lines infected with recombinant vaccinia viruses expressing each of nine individual RS virus proteins. The use of peripheral blood dendritic cells to present antigen gave more easily reproducible ...

  14. Bovine aortic endothelial cells are susceptible to Hantaan virus infection

    International Nuclear Information System (INIS)

    Hantavirus serotype Hantaan (HTN) is one of the causative agents of hemorrhagic fever with renal syndrome (HFRS, lethality up to 10%). The natural host of HTN is Apodemus agrarius. Recent studies have shown that domestic animals like cattle are sporadically seropositive for hantaviruses. In the present study, the susceptibility of bovine aortic endothelial cells (BAEC) expressing αVβ3-integrin to a HTN infection was investigated. Viral nucleocapsid protein and genomic RNA segments were detected in infected BAEC by indirect immunofluorescence assay, Western blot analysis, and reverse transcription-polymerase chain reaction (RT-PCR), respectively. The results of this study strongly support our previous observation on Puumala virus (PUU) that has been propagated efficiently in BAEC. These findings open a new window to contemplate the ecology of hantavirus infection and transmission route from animal to man

  15. The ancient Virus World and evolution of cells

    OpenAIRE

    Dolja Valerian V; Senkevich Tatiana G; Koonin Eugene V

    2006-01-01

    Abstract Background Recent advances in genomics of viruses and cellular life forms have greatly stimulated interest in the origins and evolution of viruses and, for the first time, offer an opportunity for a data-driven exploration of the deepest roots of viruses. Here we briefly review the current views of virus evolution and propose a new, coherent scenario that appears to be best compatible with comparative-genomic data and is naturally linked to models of cellular evolution that, from ind...

  16. Protection against lethal challenge by Ebola virus-like particles produced in insect cells

    OpenAIRE

    Sun, Yuliang; Carrion, Ricardo; Ye, Ling; Wen, Zhiyuan; Ro, Young-Tae; Brasky, Kathleen; Ticer, Anysha E.; Schwegler, E. Ellen; Patterson, Jean L.; Compans, Richard W.; Yang, Chinglai

    2008-01-01

    Ebola virus-like particles (VLPs) were produced in insect cells using a recombinant baculovirus expression system and their efficacy for protection against Ebola virus infection was investigated. Two immunizations with 50 ug Ebola VLPs (high dose) induced a high level of antibodies against Ebola GP that exhibited strong neutralizing activity against GP-mediated virus infection and conferred complete protection of vaccinated mice against lethal challenge by a high dose of mouse-adapted Ebola v...

  17. Effective Binding of a Phosphatidylserine-Targeting Antibody to Ebola Virus Infected Cells and Purified Virions

    OpenAIRE

    Dowall, S. D.; Graham, V A; Corbin-Lickfett, K; C. Empig; Schlunegger, K.; Bruce, C B; Easterbrook, L.; Hewson, R.

    2015-01-01

    Ebola virus is responsible for causing severe hemorrhagic fevers, with case fatality rates of up to 90%. Currently, no antiviral or vaccine is licensed against Ebola virus. A phosphatidylserine-targeting antibody (PGN401, bavituximab) has previously been shown to have broad-spectrum antiviral activity. Here, we demonstrate that PGN401 specifically binds to Ebola virus and recognizes infected cells. Our study provides the first evidence of phosphatidylserine-targeting antibody reactivity again...

  18. Ultrastructural study of long-term canine distemper virus infection in tissue culture cells.

    OpenAIRE

    Narang, H K

    1982-01-01

    The morphogenesis of canine distemper virus was studied in Vero cell cultures for 43 days post-inoculation. Active replication of the virus was observed by electron microscopy and assay from 12 h after inoculation on, and peak production was observed on days 5, 14, and 22. From day 28 on, constant but smaller amounts of infectious virus were detected. Two ultrastructural types of intracytoplasmic nucleoprotein filaments were observed; although they first appeared at different times, their sub...

  19. Characterization of Virus-Responsive Plasmacytoid Dendritic Cells in the Rhesus Macaque

    OpenAIRE

    Chung, Eugene; Amrute, Sheela B.; Abel, Kristina; Gupta, Gunjan; Wang, Yichuan; Miller, Christopher J.; Fitzgerald-Bocarsly, Patricia

    2005-01-01

    Plasmacytoid dendritic cells (PDC) are potent producers of alpha interferon (IFN-α) in response to enveloped viruses and provide a critical link between the innate and adaptive immune responses. Although the loss of peripheral blood PDC function and numbers has been linked to human immunodeficiency virus (HIV) progression in humans, a suitable animal model is needed to study the effects of immunodeficiency virus infection on PDC function. The rhesus macaque SIV model closely mimics human HIV ...

  20. Class I defective herpes simplex virus DNA as a molecular cloning vehicle in eucaryotic cells.

    OpenAIRE

    Barnett, J W; Eppstein, D A; Chan, H W

    1983-01-01

    Defective herpes simplex virus type 1 genomes are composed of head-to-tail tandem repeats of small regions of the nondefective genome. Monomeric repeat units of class I defective herpes simplex virus genomes were cloned into bacterial plasmids. The repeat units functioned as replicons since both viral and convalently linked bacterial plasmid DNA replicated (with the help of DNA from nondefective virus) when transfected into rabbit skin cells. Recombinant plasmids were packaged into virions an...

  1. Interaction of Sendai virus (HVJ) with chicken red blood cells, 1

    International Nuclear Information System (INIS)

    On the course of Sendai virus purification by adsorption-elution onto chicken red blood cells, it was found that the intensities of the hemagglutinating activities of each viruses were different. The cause of this differency is due to different contents of glucosamine containing high molecular substances which may situate on the surface of virions, from the results of electrophoretical and chemical analysis of the components of both adsorbed and unadsorbed viruses. (auth.)

  2. [Functional activity of lymphoblastoid cells infected by human adenovirus type 2 and Epstein-Barr virus].

    Science.gov (United States)

    Povnitsa, O Iu; Diachenko, N S; Nosach, L N; Olevinskaia, Z M; Zhovnovataia, V L; Polishchuk, V N; Spivak, N Ia

    2005-01-01

    The paper deals with the influence of the adenovirus (Ad) and Epstein-Barr virus (EBV) on functional activity of lymphocytes, in particular, the production of alpha- and gamma-interferons, tumor necrosis factor (TNF) in conditions of mono- or double infection of B- and T-phenotype (CEM) lymphoblastoid cells. It is shown, that Ad, EBV or both viruses induce high enough levels of interferon on both lines of cells and in control epithelial cells. The lymphoblastoid cells infected by viruses deep ability to synthesize alpha- and gamma-interferons under the influence of the corresponding inducers (Newcastle disease virus and hemagglutinine). Nevertheless, the levels of their formation are not high. Rather high parameters of activity of the tumor necrosis factor (TNF) were revealed during a day in the initial B95-8 cells and superinfected Ad after the effect of LPS of E. coli. Their activity in CEM cells also did not depend on the infection type. PMID:16018208

  3. Single cell mass cytometry reveals remodeling of human T cell phenotypes by varicella zoster virus.

    Science.gov (United States)

    Sen, Nandini; Mukherjee, Gourab; Arvin, Ann M

    2015-11-15

    The recent application of mass cytometry (CyTOF) to biology provides a 'systems' approach to monitor concurrent changes in multiple host cell factors at the single cell level. We used CyTOF to evaluate T cells infected with varicella zoster virus (VZV) infection, documenting virus-mediated phenotypic and functional changes caused by this T cell tropic human herpesvirus. Here we summarize our findings using two complementary panels of antibodies against surface and intracellular signaling proteins to elucidate the consequences of VZV-mediated perturbations on the surface and in signaling networks of infected T cells. CyTOF data was analyzed by several statistical, analytical and visualization tools including hierarchical clustering, orthogonal scaling, SPADE, viSNE, and SLIDE. Data from the mass cytometry studies demonstrated that VZV infection led to 'remodeling' of the surface architecture of T cells, promoting skin trafficking phenotypes and associated with concomitant activation of T-cell receptor and PI3-kinase pathways. This method offers a novel approach for understanding viral interactions with differentiated host cells important for pathogenesis. PMID:26213183

  4. Visualization of the African swine fever virus infection in living cells by incorporation into the virus particle of green fluorescent protein-p54 membrane protein chimera

    International Nuclear Information System (INIS)

    Many stages of African swine fever virus infection have not yet been studied in detail. To track the behavior of African swine fever virus (ASFV) in the infected cells in real time, we produced an infectious recombinant ASFV (B54GFP-2) that expresses and incorporates into the virus particle a chimera of the p54 envelope protein fused to the enhanced green fluorescent protein (EGFP). The incorporation of the fusion protein into the virus particle was confirmed immunologically and it was determined that p54-EGFP was fully functional by confirmation that the recombinant virus made normal-sized plaques and presented similar growth curves to the wild-type virus. The tagged virus was visualized as individual fluorescent particles during the first stages of infection and allowed to visualize the infection progression in living cells through the viral life cycle by confocal microscopy. In this work, diverse potential applications of B54GFP-2 to study different aspects of ASFV infection are shown. By using this recombinant virus it was possible to determine the trajectory and speed of intracellular virus movement. Additionally, we have been able to visualize for first time the ASFV factory formation dynamics and the cytophatic effect of the virus in live infected cells. Finally, we have analyzed virus progression along the infection cycle and infected cell death as time-lapse animations

  5. Ethanol suppression of peripheral blood mononuclear cell trafficking across brain endothelial cells in immunodeficiency virus infection

    Directory of Open Access Journals (Sweden)

    Lola C Hudson

    2010-01-01

    Full Text Available Lola C Hudson1, Brenda A Colby1, Rick B Meeker21Department of Molecular Biosciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA; 2Department of Neurology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USAAbstract: Earlier studies suggested that the combination of alcohol use and immunodeficiency virus infection resulted in more severe neurologic disease than either condition individually. These deleterious interactions could be due to increased immune cell and virus trafficking or may result from interactions between ethanol and human immunodeficiency virus (HIV-associated toxicity within the brain. To determine the extent to which increased trafficking played a role, we examined the effect of ethanol on the migration of different peripheral blood mononuclear cell (PBMCs subsets across a brain endothelial cell monolayer. We utilized combinations of feline brain endothelial cells with astrocytes, and/or microglia with either acute exposure to 0.08 g/dL ethanol, a combination of ethanol and feline immunodeficiency virus (FIV, or FIV alone. Adherence of PBMCs to endothelium was increased in all combinations of cells with the addition of ethanol. Despite increased PBMC adhesion with ethanol treatment, transmigration of B cells, monocytes, CD4 T cells and CD8 T cells was not increased and was actually decreased in the presence of astrocytes. Expression of three common adhesion molecules, intercellular adhesion molecule-1 (ICAM1, ICAM2, and vascular cell adhesion molecule, was unchanged or slightly decreased by ethanol. This indicated that although adherence is increased by ethanol it is not due to an increased expression of adhesion molecules. RANTES, MIP1α, MIP1β, and MCP-1 mRNA expression was also studied in brain endothelial cells, astrocytes and microglia by reverse transcriptase-polymerase chain reaction. Ethanol treatment of astrocytes resulted in modest changes of

  6. Correlation between cell killing and massive second-round superinfection by members of some subgroups of avian leukosis virus.

    OpenAIRE

    Weller, S K; Joy, A E; Temin, H M

    1980-01-01

    Avian leukosis viruses of subgroups B, D, and F are cytopathic for chicken cells, whereas viruses of subgroups A, C, and E are not. The amounts of unintegrated linear viral DNA in cells at different times after infection with cytopathic or noncytopathic viruses were determined by hybridization and transfection assays. Shortly after infection, there is a transient accumulation of unintegrated linear viral DNA in cells infected with cytopathic avian leukosis viruses. By 10 days after infection,...

  7. Influenza virus intracellular replication dynamics, release kinetics, and particle morphology during propagation in MDCK cells.

    Science.gov (United States)

    Frensing, Timo; Kupke, Sascha Y; Bachmann, Mandy; Fritzsche, Susanne; Gallo-Ramirez, Lili E; Reichl, Udo

    2016-08-01

    Influenza viruses are respiratory pathogens and can cause severe disease. The best protection against influenza is provided by annual vaccination. These vaccines are produced in embryonated chicken eggs or using continuous animal cell lines. The latter processes are more flexible and scalable to meet the growing global demand. However, virus production in cell cultures is more expensive. Hence, further research is needed to make these processes more cost-effective and robust. We studied influenza virus replication dynamics to identify factors that limit the virus yield in adherent Madin-Darby canine kidney (MDCK) cells. The cell cycle stage of MDCK cells had no impact during early infection. Yet, our results showed that the influenza virus RNA synthesis levels out already 4 h post infection at a time when viral genome segments are exported from the nucleus. Nevertheless, virus release occurred at a constant rate in the following 16 h. Thereafter, the production of infectious viruses dramatically decreased, but cells continued to produce particles contributing to the hemagglutination (HA) titer. The majority of these particles from the late phase of infection were deformed or broken virus particles as well as large membranous structures decorated with viral surface proteins. These changes in particle characteristics and morphology need to be considered for the optimization of influenza virus production and vaccine purification steps. Moreover, our data suggest that in order to achieve higher cell-specific yields, a prolonged phase of viral RNA synthesis and/or a more efficient release of influenza virus particles is required. PMID:27129532

  8. Hepatitis C Virus Immune Escape via Exploitation of a Hole in the T cell Repertoire

    OpenAIRE

    Wolfl, Matthias; Rutebemberwa, Alleluiah; Mosbruger, Timothy; Mao, Qing; Li, Hongmei; Netski, Dale; Ray, Stuart C.; Pardoll, Drew; Sidney, John; Sette, Alessandro; Allen, Todd; Kuntzen, Thomas; Kavanagh, Daniel G.; Kuball, Jurgen; Greenberg, Philip D.

    2008-01-01

    Hepatitis C virus (HCV) infection frequently persists despite eliciting substantial virus-specific immune responses. Thus, HCV infection provides a setting in which to investigate mechanisms of immune escape that allow for viral persistence. Viral amino acid substitutions resulting in decreased MHC binding or impaired antigen processing of T cell epitopes reduce antigen density on the cell surface, permitting evasion of T cell responses in chronic viral infection. Substitutions in viral epito...

  9. Susceptibility of Rat-Derived Cells to Replication by Human Immunodeficiency Virus Type 1

    OpenAIRE

    Keppler, Oliver T.; Yonemoto, Wesley; Welte, Frank J.; Patton, Kathryn S.; Iacovides, Demetris; Atchison, Robert E.; Ngo, Tuan; Hirschberg, David L.; Roberto F Speck; Goldsmith, Mark A.

    2001-01-01

    Progress in developing a small animal model of human immunodeficiency virus type 1 (HIV-1) disease would greatly facilitate studies of transmission, pathogenesis, host immune responses, and antiviral strategies. In this study, we have explored the potential of rats as a susceptible host. In a single replication cycle, rat cell lines Rat2 and Nb2 produced infectious virus at levels 10- to 60-fold lower than those produced by human cells. Rat-derived cells supported substantial levels of early ...

  10. Quantitative analysis of the lipidomes of the influenza virus envelope and MDCK cell apical membrane

    OpenAIRE

    Gerl, Mathias J.; Sampaio, Julio L; Urban, Severino; Kalvodova, Lucie; Verbavatz, Jean-Marc; Binnington, Beth; Lindemann, Dirk; Lingwood, Clifford A.; Shevchenko, Andrej; Schroeder, Cornelia; Simons, Kai

    2012-01-01

    The influenza virus (IFV) acquires its envelope by budding from host cell plasma membranes. Using quantitative shotgun mass spectrometry, we determined the lipidomes of the host Madin–Darby canine kidney cell, its apical membrane, and the IFV budding from it. We found the apical membrane to be enriched in sphingolipids (SPs) and cholesterol, whereas glycerophospholipids were reduced, and storage lipids were depleted compared with the whole-cell membranes. The virus membrane exhibited a furthe...

  11. B Cell Infection and Activation by Rabies Virus-Based Vaccines

    OpenAIRE

    Lytle, Andrew G.; Norton, James E.; Dorfmeier, Corin L.; Shen, Shixue; McGettigan, James P.

    2013-01-01

    Replication-deficient rabies viruses (RABV) are promising rabies postexposure vaccines due to their prompt and potent stimulation of protective virus neutralizing antibody titers, which are produced in mice by both T-dependent and T-independent mechanisms. To promote such early and robust B cell stimulation, we hypothesized that live RABV-based vaccines directly infect B cells, thereby activating a large pool of antigen-presenting cells (APCs) capable of providing early priming and costimulat...

  12. A novel mechanism of late gene silencing drives Simian virus 40 transformation of human mesothelial cells

    OpenAIRE

    Carbone, Michele; Pannuti, Antonio; Zhang, Lei; Testa, Joseph R.; Bocchetta, Maurizio

    2008-01-01

    Suppression of the late gene expression, usually by integration of the viral DNA into the host genome, is a critical step in DNA tumor viruses carcinogenesis. Simian virus 40 (SV40) induces high rates of transformation in infected primary human mesothelial cells (S-HM) in tissue culture, leading to the formation of immortal cell lines (S-HML). The studies described here were designed to elucidate the unusual susceptibility of primary human mesothelial cells (HM) to SV40 carcinogenesis.

  13. Gammaherpesvirus-driven plasma cell differentiation regulates virus reactivation from latently infected B lymphocytes.

    Directory of Open Access Journals (Sweden)

    Xiaozhen Liang

    2009-11-01

    Full Text Available Gammaherpesviruses chronically infect their host and are tightly associated with the development of lymphoproliferative diseases and lymphomas, as well as several other types of cancer. Mechanisms involved in maintaining chronic gammaherpesvirus infections are poorly understood and, in particular, little is known about the mechanisms involved in controlling gammaherpesvirus reactivation from latently infected B cells in vivo. Recent evidence has linked plasma cell differentiation with reactivation of the human gammaherpesviruses EBV and KSHV through induction of the immediate-early viral transcriptional activators by the plasma cell-specific transcription factor XBP-1s. We now extend those findings to document a role for a gammaherpesvirus gene product in regulating plasma cell differentiation and thus virus reactivation. We have previously shown that the murine gammaherpesvirus 68 (MHV68 gene product M2 is dispensable for virus replication in permissive cells, but plays a critical role in virus reactivation from latently infected B cells. Here we show that in mice infected with wild type MHV68, virus infected plasma cells (ca. 8% of virus infected splenocytes at the peak of viral latency account for the majority of reactivation observed upon explant of splenocytes. In contrast, there is an absence of virus infected plasma cells at the peak of latency in mice infected with a M2 null MHV68. Furthermore, we show that the M2 protein can drive plasma cell differentiation in a B lymphoma cell line in the absence of any other MHV68 gene products. Thus, the role of M2 in MHV68 reactivation can be attributed to its ability to manipulate plasma cell differentiation, providing a novel viral strategy to regulate gammaherpesvirus reactivation from latently infected B cells. We postulate that M2 represents a new class of herpesvirus gene products (reactivation conditioners that do not directly participate in virus replication, but rather facilitate virus

  14. Avian sarcoma and leukosis virus-receptor interactions: From classical genetics to novel insights into virus-cell membrane fusion

    International Nuclear Information System (INIS)

    For over 40 years, avian sarcoma and leukosis virus (ASLV)-receptor interactions have been employed as a useful model system to study the mechanism of retroviral entry into cells. Pioneering studies on this system focused upon the genetic basis of the differential susceptibilities of different lines of chickens to infection by distinct subgroups of ASLV. These studies led to the definition of three distinct autosomal recessive genes that were predicted to encode cellular receptors for different viral subgroups. They also led to the concept of viral interference, i.e. the mechanism by which infection by one virus can render cells resistant to reinfection by other viruses that use the same cellular receptor. Here, we review the contributions that analyses of the ASLV-receptor system have made in unraveling the mechanisms of retroviral entry into cells and focus on key findings such as identification and characterization of the ASLV receptor genes and the subsequent elucidation of an unprecedented mechanism of virus-cell fusion. Since many of the initial findings on this system were published in the early volumes of Virology, this subject is especially well suited to this special anniversary issue of the journal

  15. Borna disease virus induces acute fatal neurological disorders in neonatal gerbils without virus- and immune-mediated cell destructions

    International Nuclear Information System (INIS)

    Borna disease virus (BDV) is a noncytolytic, neurotropic RNA virus that is known to cause neurological disturbances in various animal species. Our previous experiment demonstrated that neonate gerbils develop an acute fatal neurological disease following infection with BDV , Virology 282, 65-76). The study suggested that BDV directly causes functional damage of neuronal cells resulting in the lethal disorder in neonatal gerbils. To extend this finding, we examined whether BDV can induce neurological diseases in the absence of virus- and immune-mediated cell destruction, by using cyclosporine A (CsA)-treated neonatal gerbils. Although CsA completely suppressed specific antibody production and brain inflammation in the infected gerbil brains, the fatal neurological disorder was not inhibited by the treatment. Furthermore, we demonstrated that CsA treatment significantly decreased brain levels of cytokines, except interleukin (IL)-1β, in the infected gerbils. These results suggested that BDV replication, as well as brain cytokines, at least IL-1β, rapidly induces fatal disturbances in gerbil brain. We demonstrate here that BDV exhibits a unique neuropathogenesis in neonatal gerbil that may be pathologically and immunologically different from those in two other established rodent models, rats and mice. With this novel rodent model of virus infection it should be possible not only to examine acute neurological disturbances without severe neuroanatomical and immunopathological alterations but also to analyze molecular and cellular damage by virus replication in the central nervous system

  16. Different host cell proteases activate the SARS-coronavirus spike-protein for cell-cell and virus-cell fusion

    International Nuclear Information System (INIS)

    Severe acute respiratory syndrome coronavirus (SARS-CoV) poses a considerable threat to human health. Activation of the viral spike (S)-protein by host cell proteases is essential for viral infectivity. However, the cleavage sites in SARS-S and the protease(s) activating SARS-S are incompletely defined. We found that R667 was dispensable for SARS-S-driven virus-cell fusion and for SARS-S-activation by trypsin and cathepsin L in a virus-virus fusion assay. Mutation T760R, which optimizes the minimal furin consensus motif 758-RXXR-762, and furin overexpression augmented SARS-S activity, but did not result in detectable SARS-S cleavage. Finally, SARS-S-driven cell-cell fusion was independent of cathepsin L, a protease essential for virus-cell fusion. Instead, a so far unknown leupeptin-sensitive host cell protease activated cellular SARS-S for fusion with target cells expressing high levels of ACE2. Thus, different host cell proteases activate SARS-S for virus-cell and cell-cell fusion and SARS-S cleavage at R667 and 758-RXXR-762 can be dispensable for SARS-S activation.

  17. Dependence of herpes simplex virus type 1-induced cell fusion on cell type

    Energy Technology Data Exchange (ETDEWEB)

    Bzik, D.J.; Person, S.

    1981-04-15

    Syncytial mutants of herpes simplex virus type 1 (HSV-1), such as syn20, cause extensive fusion of human embryonic lung (HEL) cells but only a small amount of fusion of human epidermoid carcinoma No. 2 (HEp-2) cells. In order to determine the cellular basis of this difference in fusion, sparse cultures of syn20-infected HEL or HEp-2 cells, previously labeled with (/sup 3/H)thymidine, were surrounded with uninfected, unlabeled HEL or HEp-2 cells. The fusion of radioactive with nonradioactive cells was determined at different times after infection using radioautography. The major difference in the fusion capacity of HEL and HEp-2 cells was not due to a difference in cell-surface receptors for a fusion factor in the two cell types. The process of infection of HEp-2 cells did not cause the plasma membranes of the cells to become refractory to fusion, because syn20-infected HEL cells fused equally well with either uninfected or infected HEp-2 cells. In a mixed infection with equal numbers of MP and its nonsyncytial parent, mP, extensive fusion was observed for infected HEL cells and significantly less fusion was observed for infected African green monkey (CV-1), baby hamster kidney (BHK-21), and HEp-2 cells.

  18. EPSTEIN-BARR VIRUS RELATED LYMPHOPROLIFERATIONS AFTER STEM CELL TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    Patrizia Chiusolo

    2009-11-01

    Full Text Available

    Epstein-Barr virus related lymphoproliferative  disorders are a rare but potentially fatal complication of allogeneic stem cell transplantation with an incidence of 1-3% and  occurring within 6 months after transplantation.  The most relevant risk factors include the use of in vivo T-cell depletion with antithymocyte globulin, HLA disparities between donor and recipient, donor type,  splenectomy etc. The higher the numbers of risk factors the higher the risk of developing Epstein-Barr virus related lymphoproliferative  disorders. Monitoring EBV viremia after transplantation is of value and it should be applied to high risk patients since it allows pre-emptive therapy initiation  at specified threshold values   and early treatment. This strategy  might reduce mortality which was >80% prior to the implementation of anti-EBV therapy . Treatment of EBV-LPD after allogeneic SCT may consist of anti-B-cell therapy (rituximab, adoptive T-cell immunotherapy or both. Rituximab treatment should be considered the first treatment option, preferably guided by intensive monitoring of EBV DNA while reduction of immunosuppression should be carefully evaluated for the risk of graft versus host disease.

  19. Persistence of Marek's disease virus in a subpopulation of B cells that is transformed by avian leukosis virus, but not in normal bursal B cells.

    OpenAIRE

    Fynan, E; Block, T M; DuHadaway, J; Olson, W; Ewert, D L

    1992-01-01

    Previous studies have described an augmentation of avian leukosis virus (ALV)-induced lymphoid leukosis in chickens that were coinfected with a serotype 2 Marek's disease virus (MDV) strain, SB-1. As a first step toward understanding the mechanism of this augmentation, we have analyzed the tropism of the MDV for the ALV-transformed B cell. After hatching, chickens were coinfected with ALV and a nonpathogenic strain of MDV, SB-1. Seventy primary and metastatic ALV-induced lymphomas that develo...

  20. Changes in cell adhesion molecule expression on T cells associated with systemic virus infection

    DEFF Research Database (Denmark)

    Andersson, E C; Christensen, Jan Pravsgaard; Marker, O;

    1994-01-01

    -4, LFA-1, and ICAM-1, are up-regulated on CD8+ cells, whereas the lymph node homing receptor MEL-14 is down-regulated during the infection; only marginal changes were observed for CD4+ cells. Basically similar but less marked results were obtained in mice infected with Pichinde virus. Further......, it was found that up-regulation of VLA-4 expression on splenic T cells correlated with influx of inflammatory cells into the cerebrospinal fluid of intracerebrally infected animals, and that the number of CD8+VLA-4hi cells increased from lymph nodes and spleen to blood and cerebrospinal fluid. These...... results support the hypothesis that up-regulation of VLA-4 is important for effector T cell homing to sites of inflammation....

  1. Mitophagy switches cell death from apoptosis to necrosis in NSCLC cells treated with oncolytic measles virus.

    Science.gov (United States)

    Xia, Mao; Meng, Gang; Jiang, Aiqin; Chen, Aiping; Dahlhaus, Meike; Gonzalez, Patrick; Beltinger, Christian; Wei, Jiwu

    2014-06-15

    Although apoptotic phenomena have been observed in malignant cells infected by measles virus vaccine strain Edmonston B (MV-Edm), the precise oncolytic mechanisms are poorly defined. In this study we found that MV-Edm induced autophagy and sequestosome 1-mediated mitophagy leading to decreased cytochrome c release, which blocked the pro-apoptotic cascade in non-small cell lung cancer cells (NSCLCs). The decrease of apoptosis by mitophagy favored viral replication. Persistent viral replication sustained by autophagy ultimately resulted in necrotic cell death due to ATP depletion. Importantly, when autophagy was impaired in NSCLCs MV-Edm-induced cell death was significantly abrogated despite of increased apoptosis. Taken together, our results define a novel oncolytic mechanism by which mitophagy switches cell death from apoptosis to more efficient necrosis in NSCLCs following MV-Edm infection. This provides a foundation for future improvement of oncolytic virotherapy or antiviral therapy. PMID:25004098

  2. Cloning and identification of measles virus receptor gene from marmoset cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The measles virus (MV) strains with mutated hemagglutinin gene (ha) lost the capacity to infect its sensitive host cells (Vero cells), but it may infect the marmoset B-lymphoblastoid cell line B95a. From above, we can presume that there is a novel cellular receptor for those measles virus strains on B95a cell s. Using the yeast two-hybrid system, we screened and cloned a novel gene--bip (B-lympho- blastoid interaction protein of marmoset) from B95a cell cDNA library, which encoded a protein interacting with measles virus hemagglutinin protein (Ha). The bip cDNA was 1540 base pairs in length and contained a unique open rea ding frame (ORF) of 1011 base pairs encoding a transmembrane protein of 337 amino acid residues. The primary structure of amino acids residue is predicted that the Bip comprised a hydrophobic transmembrane domain and a hydrophobic leader region. The researches about the deletion mutants showed that the deletion of tran smembrane domain in Bip did not affect the interaction between Bip and Ha protei ns. Expression of bip in measles virus non-permissive cell line--CHO (Chinese hamster ovary) cells was performed to prove that CHO/Bip can be infected by meas les virus and then turned to the MV permissive cells. We concluded that the bip gene is a novel measles virus receptor gene in marmoset B-lymphoblastoid cells.

  3. Recombinant Yellow Fever Vaccine Virus 17D Expressing Simian Immunodeficiency Virus SIVmac239 Gag Induces SIV-Specific CD8+ T-Cell Responses in Rhesus Macaques ▿

    OpenAIRE

    Bonaldo, Myrna C.; Martins, Mauricio A.; Rudersdorf, Richard; Mudd, Philip A.; Sacha, Jonah B.; Piaskowski, Shari M.; Costa Neves, Patrícia C.; Veloso de Santana, Marlon G.; Vojnov, Lara; Capuano, Saverio; Rakasz, Eva G.; Wilson, Nancy A.; Fulkerson, John; Sadoff, Jerald C.; Watkins, David I.

    2010-01-01

    Here we describe a novel vaccine vector for expressing human immunodeficiency virus (HIV) antigens. We show that recombinant attenuated yellow fever vaccine virus 17D expressing simian immunodeficiency virus SIVmac239 Gag sequences can be used as a vector to generate SIV-specific CD8+ T-cell responses in the rhesus macaque. Priming with recombinant BCG expressing SIV antigens increased the frequency of these SIV-specific CD8+ T-cell responses after recombinant YF17D boosting. These recombinan...

  4. Fowl plague virus replication in mammalian cell-avian erythrocyte heterokaryons: studies concerning the actinomycin D and ultra-violet lig sensitive phase in influenza virus replication

    International Nuclear Information System (INIS)

    The replication of fowl plague virus in BHK and L cells specifically blocked prior to infection with inhibitors of influenza virus replication (actinomycin D and ultraviolet light irradiation) has been studied by the introduction of a metabolically dormant avian erythrocyte nucleus. This permits the synthesis of just the influenza virus nucleoprotein in actinomycin D (but not ultraviolet light) blocked cells. The NP antigen is first detected in the avian erythrocyte nucleus and subsequently in the heterokaryon cytoplasm

  5. Virus-host interactions in persistently FMDV-infected cells derived from bovine pharynx

    Science.gov (United States)

    Foot-and-mouth disease virus (FMDV) produces a disease in cattle characterized by vesicular lesions and a persistent infection with asymptomatic low-level production of virus. Here we describe the establishment of a persistently infected primary cell culture derived from bovine pharynx tissue (PBPT)...

  6. Cotranslational disassembly of flock house virus in a cell-free system.

    OpenAIRE

    Hiscox, J A; Ball, L A

    1997-01-01

    Intact, purified particles of the nodaviruses flock house virus and nodamura virus that were either transfected into cells that were resistant to infection or introduced into in vitro translation systems directed the synthesis of viral proteins. We infer that direct interaction of these nodavirus particles with cytoplasmic components mediated virion disassembly that resulted in release of the viral RNA.

  7. The infection of chicken tracheal epithelial cells with a H6N1 avian influenza virus.

    Directory of Open Access Journals (Sweden)

    Ching-I Shen

    Full Text Available Sialic acids (SAs linked to galactose (Gal in α2,3- and α2,6-configurations are the receptors for avian and human influenza viruses, respectively. We demonstrate that chicken tracheal ciliated cells express α2,3-linked SA, while goblet cells mainly express α2,6-linked SA. In addition, the plant lectin MAL-II, but not MAA/MAL-I, is bound to the surface of goblet cells, suggesting that SA2,3-linked oligosaccharides with Galβ1-3GalNAc subterminal residues are specifically present on the goblet cells. Moreover, both α2,3- and α2,6-linked SAs are detected on single tracheal basal cells. At a low multiplicity of infection (MOI avian influenza virus H6N1 is exclusively detected in the ciliated cells, suggesting that the ciliated cell is the major target cell of the H6N1 virus. At a MOI of 1, ciliated, goblet and basal cells are all permissive to the AIV infection. This result clearly elucidates the receptor distribution for the avian influenza virus among chicken tracheal epithelial cells and illustrates a primary cell model for evaluating the cell tropisms of respiratory viruses in poultry.

  8. Herpes simplex virus-mediated human hypoxanthine-guanine phosphoribosyltransferase gene transfer into neuronal cells

    Energy Technology Data Exchange (ETDEWEB)

    Palella, T.D.; Silverman, L.J.; Schroll, C.T.; Homa, F.L.; Levine, M.; Kelley, W.N.

    1988-01-01

    The virtually complete deficiency of the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) results in a devastating neurological disease, Lesch-Nyhan syndrome. Transfer of the HPRT gene into fibroblasts and lymphoblasts in vitro and into hematopoietic cells in vivo has been accomplished by other groups with retroviral-derived vectors. It appears to be necessary, however, to transfer the HPRT gene into neuronal cells to correct the neurological dysfunction of this disorder. The neurotropic virus herpes simplex virus type 1 has features that make it suitable for use as a vector to transfer the HPRT gene into neuronal tissue. This report describes the isolation of an HPRT-deficient rat neuroma cell line, designated B103-4C, and the construction of a recombinant herpes simplex virus type 1 that contained human HPRT cDNA. These recombinant viruses were used to infect B103-4C cells. Infected cells expressed HPRT activity which was human in origin.

  9. Staphylococcus aureus and influenza A virus stimulate human bronchoalveolar cells to release histamine and leukotrienes

    DEFF Research Database (Denmark)

    Clementsen, P; Bisgaard, H; Pedersen, M;

    1989-01-01

    Mediator release was examined from superficially lying cells in the airway epithelium obtained by bronchoalveolar lavage (BAL) in 13 non-atopic individuals. The BAL-cells were incubated (20 min, 37 degrees C) with Staphylococcus (Staph.) aureus or with human influenza A virus Staph. aureus...... was found to release histamine from cells from 7 of the 13 individuals and influenza A virus in 3 of 5 persons. Furthermore, Staph, aureus stimulated the BAL-cells to release leukotriene B4 in 7 of 11 subjects, whereas no release was found by influenza A virus in 7 examined persons. When cells from 4...... persons were stimulated with Staph. aureus no release of leukotriene C4 was found. The mediator release caused by bacteria and virus might be of importance for the exacerbation of bronchial asthma in upper respiratory tract infections, since histamine is assumed to increase the epithelial permeability...

  10. Lysis of uninfected and virus-infected cells in vivo: a rejection mechanism in addition to that mediated by natural killer cells.

    OpenAIRE

    Biron, C. A.; Habu, S.; Okumura, K.; Welsh, R. M.

    1984-01-01

    To examine the lysis of virus-infected cells in vivo, uninfected and lymphocytic choriomeningitis virus (LCMV)-infected L-929 cells were labeled in vitro with [125I]-iododeoxyuridine and implanted intravenously into mice. Natural cytotoxicity against both uninfected and virus-infected cells was demonstrated in normal uninfected mice, but LCMV-infected cells were cleared from the lungs and whole bodies more rapidly than uninfected cells. Treatment of L-929 cells with defective interfering LCMV...

  11. Molecular evolution of hepatitis A virus in a human diploid cell line

    Institute of Scientific and Technical Information of China (English)

    Cai-Hua Tang; Jiang-Sen Mao; Shao-Ai Chai; Yong Chen; Fang-Cheng Zhuang

    2007-01-01

    AIM: To investigate the hotspots, direction, and the time course of evolution of hepatitis A virus in the process of consecutive cell culture passage in human KMB17 diploid cells.METHODS: Wild type hepatitis A virus H2w was serially propagated in KMB17 cells until passage 30, and the full-length genomes of H2w and its six chosen progenies were determined by directly sequencing RT-PCR products amplified from viral genomic RNA. Alignment comparison of sequences from H2w with its six progenies and phylogenetic analysis of the whole VP1 region from H2w, progenies of H2w, and other cell culture adapted hepatitis A virus were then carried out to obtain data on the molecular evolution of hepatitis A virus in the process of consecutive passage in KMB17 cells.RESULTS: Most of the mutations occurred by passage 5 and several hotspots related to adaptation of the virus during cell growth were observed. After that stage, few additional mutations occurred through the remaining duration of passage in KMB17 cells except for mutation in the virulence determinants, which occurred in the vicinity of passage 15. The phylogenetic analysis of the whole VP1 region suggested that the progenies of H2w evolved closely to other cell culture adapted hepatitis A virus, i.e. MBB, L-A-1, other than its progenitor H2w.CONCLUSION: Hepatitis A virus served as a useful model for studying molecular evolution of viruses in a given environment. The information obtained in this study may provide assistance in cultivating the next generation of a seed virus for live hepatitis A vaccine production.

  12. Mixed cells in shell vials for detection of influenza viruses and enteroviruses from clinical specimens

    Institute of Scientific and Technical Information of China (English)

    汪千力

    2013-01-01

    Objective To evaluate shell vials of MHV,a combination of Madin-Darby canine kidney cells(MDCK),human epidermoid cancer cells(Hep-2) and African green monkey kidney cells(Vero), and conventional cell culture in detecting influenza viruses and enterovirus from

  13. Affinity Purification of Influenza Virus Ribonucleoprotein Complexes from the Chromatin of Infected Cells

    OpenAIRE

    Chase, Geoffrey P.; Schwemmle, Martin

    2012-01-01

    Like all negative-strand RNA viruses, the genome of influenza viruses is packaged in the form of viral ribonucleoprotein complexes (vRNP), in which the single-stranded genome is encapsidated by the nucleoprotein (NP), and associated with the trimeric polymerase complex consisting of the PA, PB1, and PB2 subunits. However, in contrast to most RNA viruses, influenza viruses perform viral RNA synthesis in the nuclei of infected cells. Interestingly, viral mRNA synthesis uses cellular pre-mRNAs a...

  14. A20 Deficiency in Lung Epithelial Cells Protects against Influenza A Virus Infection

    OpenAIRE

    Maelfait, Jonathan; Roose, Kenny; Vereecke, Lars; Mc Guire, Conor; Sze, Mozes; Schuijs, Martijn; Willart, Monique; Ibanez, Lorena; Hammad, Hamida; LAMBRECHT, Bart; Beyaert, Rudi; Saelens, Xavier; Loo, Geert

    2016-01-01

    A20 negatively regulates multiple inflammatory signalling pathways. We here addressed the role of A20 in club cells (also known as Clara cells) of the bronchial epithelium in their response to influenza A virus infection. Club cells provide a niche for influenza virus replication, but little is known about the functions of these cells in antiviral immunity. Using airway epithelial cell-specific A20 knockout (A20(AEC-KO)) mice, we show that A20 in club cells critically controls innate immune r...

  15. CELL SHAPE AND HEXOSE TRANSPORT IN NORMAL AND VIRUS-TRANSFORMED CELLS IN CULTURE

    Energy Technology Data Exchange (ETDEWEB)

    Bissell, M.J.; Farson, D.; Tung, A.S.C.

    1976-07-01

    The rate of hexose transport was compared in normal and virus-transformed cells on a monolayer and in suspension. It was shown that: (1) Both trypsin-removed cells and those suspended for an additional day in methyl cellulose had decreased rates of transport and lower available water space when compared with cells on a monolayer. Thus, cell shape affects the overall rate of hexose transport, especially at higher sugar concentrations. (2) Even in suspension, the initial transport rates remained higher in transformed cells with reference to normal cells. Scanning electron micrographs of normal and transformed chick cells revealed morphological differences only in the flat state. This indicates that the increased rate of hexose transport after transformation is not due to a difference in the shape of these cells on a monolayer. The relation between the geometry of cells, transport rates, and growth regulation is undoubtedly very complex, and our knowledge of these relationships is still very elementary. In a recent review on the influence of geometry on control of cell growth, Folkman and Greenspan (1) pointed out that the permeability of cells in a flat versus a spherical state may indeed be very different. The growth properties of cells on a surface and in suspension have been compared often (1-5). However, with one exception. little is known about the changes in transport properties when cell shape is changed. Foster and Pardee (6) demonstrated that the active transport of a-aminoisobutyric acid was reduced 2.5 times in suspension cultures of Chinese hamster cells with respect to the cells grown on a coverslip. They attributed this to the smaller surface area of suspended cells. While it is not clear why active transport should be dependent on the surface area available, it is possible that once the cells assume a spherical configuration, the carrier proteins are redistributed in such a way as to make them less accessible to the substrate. What happens to

  16. Adeno-associated virus sensitizes HeLa cell tumors to gamma rays.

    Science.gov (United States)

    Walz, C; Schlehofer, J R; Flentje, M; Rudat, V; zur Hausen, H

    1992-01-01

    Infection with the helper virus-dependent human parvovirus adeno-associated virus (AAV) is known to interfere with cellular transformation in vitro and oncogenesis in vivo. Here we report on sensitization to gamma irradiation by AAV infection of cells in culture and of tumors established from HeLa cells grafted into immunodeficient (nude) mice: infection of HeLa cells with AAV type 2 enhanced cell killing and reduced plating efficiency after irradiation compared with uninfected cells. Similarly, HeLa cell tumors in nude mice displayed a reduced growth rate and were more sensitive to gamma irradiation when the animals were infected with AAV type 2 prior to or after tumor cell inoculation. Since no pathogenicity is known for AAV, the ability of this virus to render radiotherapy of human tumor cells more efficient may up open novel approaches in cancer treatment. Images PMID:1323717

  17. Screening for Recombinant Avian Leukosis Viruses in Cell Cultures Inoculated with Various Subgroups of Virus

    Science.gov (United States)

    Chicken embryo fibroblasts (CEFs) prepared from ADOL SPF embryos were co-infected with different concentration ratios of subgroups A, J and E avian leukosis virus (ALV). Inoculated cultures were screened for recombination among the ALV strains. Potential recombinant viruses were purified by limiting...

  18. Human T lymphotropic virus type I in arthropathy and autoimmune disorders.

    Science.gov (United States)

    Nishioka, K; Sumida, T; Hasunuma, T

    1996-08-01

    The progressive nature of the disease and the persistent inflammation affecting various organs are common features of idiopathic autoimmune disorders of unknown etiology. Therefore, the HTLV-I-associated disorders described in the present review are outstandingly important models for our understanding of the pathologic mechanisms of organ-specific immune disorders. HTLV-I arthropathy is characterized by chronic inflammatory and proliferative synovitis with lymphoid follicles and pannus formation in the affected joints, indistinguishable from the findings in idiopathic RA. The presence of the tax gene in HTLV-I-negative SS patients suggests that it is responsible for the exocrine gland abnormality, characterized by extensive lymphoproliferative epithelial lesions. Furthermore, the pulmonary lesions of HTLV-I bronchopneumonopathy are similar to those of idiopathic interstitial pneumonitis. Based on these observations, the clinical findings associated with the immunologic abnormalities in HTLV-I-infected patients provide us with valuable information for understanding the pathogenetic mechanisms of chronic inflammatory conditions associated with immune regulatory disorders. Although the clinical and pathologic features of the 2 common HTLV-I-associated disorders, ATL and HAM/TSP, have been well characterized and are clearly distinguishable from those of the idiopathic forms of these disorders, other HTLV-I-related autoimmune diseases, e.g., arthropathy, SS, or bronchopneumonopathy, are clinically indistinguishable from the idiopathic forms of the diseases. Such similarity may serve as a clue to the pathogenetic mechanisms of idiopathic autoimmune disorders. PMID:8702452

  19. Friend and Moloney murine leukemia viruses specifically recombine with different endogenous retroviral sequences to generate mink cell focus-forming viruses.

    OpenAIRE

    Evans, L H; Cloyd, M W

    1985-01-01

    A group of mink cell focus-forming (MCF) viruses was derived by inoculation of NFS/N mice with Moloney murine leukemia virus (Mo-MuLV 1387) and was compared to a similarly derived group of MCF viruses from mice inoculated with Friend MuLV (Fr-MuLV 57). Antigenic analyses using monoclonal antibodies specific for MCF virus and xenotropic MuLV envelope proteins and genomic structural analyses by RNase T1-resistant oligonucleotide finger-printing indicated that the Moloney and Friend MCF viruses ...

  20. HTLV-1: ancient virus, new challenges

    Directory of Open Access Journals (Sweden)

    Marzieh Rahimzadegan

    2014-08-01

    Full Text Available Human T-lymphotropic virus (HTLV-1 is an ancient pathogen for human being but arising and recognized recently. The routes of transmission are vertical (mainly by breastfeeding, unsafe sexual contacts and through contaminated blood components specially in whom need frequent and repeated blood transfusions such as permanent anemia due to blood loss in hemophilia and major thalassemia. Patients who should undergo hemodialysis in their lifelong are another instance for increased risk of HTLV-1 exposure. The main HTLV-1-associated diseases are tropical spastic tetraparesis (HAM/TSP, an inflammatory myelopathy and adult T-cell leukemia (ATL. Although HTLV-1 is scattered around the world, only in endemic areas where prevalence rate is more than 1%, viral burden of infection have accumulated. Japan, Southern and Central parts of Africa, Caribbean basin and Iran are examples of endemic areas of HTLV-1. In this article, a rapid and brief review of HTLV-1 virology, immunology and pathogenesis have emerged. In addition, a short debate has driven about current statues of HTLV-1 in Iran.

  1. Sterilizing immunity to influenza virus infection requires local antigen-specific T cell response in the lungs

    Science.gov (United States)

    Dutta, Avijit; Huang, Ching-Tai; Lin, Chun-Yen; Chen, Tse-Ching; Lin, Yung-Chang; Chang, Chia-Shiang; He, Yueh-Chia

    2016-01-01

    Sterilizing immunity is a unique immune status, which prevents effective virus infection into the host. It is different from the immunity that allows infection but with subsequent successful eradication of the virus. Pre-infection induces sterilizing immunity to homologous influenza virus challenge in ferret. In our antigen-specific experimental system, mice pre-infected with PR8 influenza virus through nasal route are likewise resistant to reinfection of the same strain of virus. The virus is cleared before establishment of effective infection. Intramuscular influenza virus injection confers protection against re-infection with facilitated virus clearance but not sterilizing immunity. Pre-infection and intramuscular injection generates comparable innate immunity and antibody response, but only pre-infection induces virus receptor reduction and efficient antigen-specific T cell response in the lungs. Pre-infection with nH1N1 influenza virus induces virus receptor reduction but not PR8-specific T cell immune response in the lungs and cannot prevent infection of PR8 influenza virus. Pre-infection with PR8 virus induced PR8-specific T cell response in the lungs but cannot prevent infection of nH1N1 virus either. These results reveal that antigen-specific T cell immunity is required for sterilizing immunity. PMID:27596047

  2. Over-expression of putative transcriptional coactivator KELP interferes with Tomato mosaic virus cell-to-cell movement.

    Science.gov (United States)

    Sasaki, Nobumitsu; Ogata, Takuya; Deguchi, Masakazu; Nagai, Shoko; Tamai, Atsushi; Meshi, Tetsuo; Kawakami, Shigeki; Watanabe, Yuichiro; Matsushita, Yasuhiko; Nyunoya, Hiroshi

    2009-03-01

    Tomato mosaic virus (ToMV) encodes a movement protein (MP) that is necessary for virus cell-to-cell movement. We have demonstrated previously that KELP, a putative transcriptional coactivator of Arabidopsis thaliana, and its orthologue from Brassica campestris can bind to ToMV MP in vitro. In this study, we examined the effects of the transient over-expression of KELP on ToMV infection and the intracellular localization of MP in Nicotiana benthamiana, an experimental host of the virus. In co-bombardment experiments, the over-expression of KELP inhibited virus cell-to-cell movement. The N-terminal half of KELP (KELPdC), which had been shown to bind to MP, was sufficient for inhibition. Furthermore, the over-expression of KELP and KELPdC, both of which were co-localized with ToMV MP, led to a reduction in the plasmodesmal association of MP. In the absence of MP expression, KELP was localized in the nucleus and the cytoplasm by the localization signal in its N-terminal half. It was also shown that ToMV amplified normally in protoplasts prepared from leaf tissue that expressed KELP transiently. These results indicate that over-expressed KELP interacts with MP in vivo and exerts an inhibitory effect on MP function for virus cell-to-cell movement, but not on virus amplification in individual cells. PMID:19236566

  3. Replication of Chinese hamster embryo cells transformed by temperature-sensitive T-antigen mutants of simian virus 40.

    OpenAIRE

    Robinson, C C; Swartzendruber, D E; Lehman, J M

    1980-01-01

    Chinese hamster embryo cells transformed by simian virus 40 temperature-sensitive T-antigen mutants replicated when confluent at 40.5 degrees C, regardless of the selection method, selection temperature, or virus strain used.

  4. Quantitative analysis of particles, genomes and infectious particles in supernatants of haemorrhagic fever virus cell cultures

    Directory of Open Access Journals (Sweden)

    Hedlund Kjell-Olof

    2011-02-01

    Full Text Available Abstract Information on the replication of viral haemorrhagic fever viruses is not readily available and has never been analysed in a comparative approach. Here, we compared the cell culture growth characteristics of haemorrhagic fever viruses (HFV, of the Arenaviridae, Filoviridae, Bunyaviridae, and Flavivridae virus families by performing quantitative analysis of cell culture supernatants by (i electron microscopy for the quantification of virus particles, (ii quantitative real time PCR for the quantification of genomes, and (iii determination of focus forming units by coating fluorescent antibodies to infected cell monolayers for the quantification of virus infectivity. The comparative analysis revealed that filovirus and RVFV replication results in a surplus of genomes but varying degrees of packaging efficiency and infectious particles. More efficient replication and packaging was observed for Lassa virus, and Dengue virus resulting in a better yield of infectious particles while, YFV turned out to be most efficient with only 4 particles inducing one FFU. For Crimean-Congo haemorrhagic fever virus (CCHFV a surplus of empty shells was observed with only one in 24 particles equipped with a genome. The complete particles turned out to be extraordinarily infectious.

  5. PARAMETERS DISTINGUISHING HERPES SIMPLEX VIRUS TYPE 2-TRANSFORMED TUMORIGENIC AND NONTUMORIGENIC RAT CELLS

    Science.gov (United States)

    A newly developed experimental model system was used to determine in vitro transformation-specific parameters which correlate with tumorigenicity. The data suggested that clonal herpes simplex virus type 2-transformed syngeneic rat embryo cells with intermediate, transformed rat ...

  6. Green Fluorescent Protein-Tagged Retroviral Envelope Protein for Analysis of Virus-Cell Interactions

    Science.gov (United States)

    Spitzer, Dirk; Dittmar, Kurt E. J.; Rohde, Manfred; Hauser, Hansjörg; Wirth, Dagmar

    2003-01-01

    Fluorescent retroviral envelope (Env) proteins were developed for direct visualization of viral particles. By fusing the enhanced green fluorescent protein (eGFP) to the N terminus of the amphotropic 4070A envelope protein, extracellular presentation of eGFP was achieved. Viruses incorporated the modified Env protein and efficiently infected cells. We used the GFP-tagged viruses for staining retrovirus receptor-positive cells, thereby circumventing indirect labeling techniques. By generating cells which conditionally expressed the GFP-tagged Env protein, we could confirm an inverse correlation between retroviral Env expression and infectivity (superinfection). eGFP-tagged virus particles are suitable for monitoring the dynamics of virus-cell interactions. PMID:12719600

  7. Protective essential oil attenuates influenza virus infection: An in vitro study in MDCK cells

    Directory of Open Access Journals (Sweden)

    Metcalf Jordan P

    2010-11-01

    Full Text Available Abstract Background Influenza is a significant cause of morbidity and mortality. The recent pandemic of a novel H1N1 influenza virus has stressed the importance of the search for effective treatments for this disease. Essential oils from aromatic plants have been used for a wide variety of applications, such as personal hygiene, therapeutic massage and even medical practice. In this paper, we investigate the potential role of an essential oil in antiviral activity. Methods We studied a commercial essential oil blend, On Guard™, and evaluated its ability in modulating influenza virus, A/PR8/34 (PR8, infection in Madin-Darby canine kidney (MDCK cells. Influenza virus was first incubated with the essential oil and infectivity in MDCK cells was quantified by fluorescent focus assay (FFA. In order to determine the mechanism of effects of essential oil in viral infection inhibition, we measured hemagglutination (HA activity, binding and internalization of untreated and oil-treated virus in MDCK cells by flow cytometry and immunofluorescence microscopy. In addition, the effect of oil treatment on viral transcription and translation were assayed by relative end-point RT-PCR and western blot analysis. Results Influenza virus infectivity was suppressed by essential oil treatment in a dose-dependent manner; the number of nascent viral particles released from MDCK cells was reduced by 90% and by 40% when virus was treated with 1:4,000 and 1:6,000 dilutions of the oil, respectively. Oil treatment of the virus also decreased direct infection of the cells as the number of infected MDCK cells decreased by 90% and 45% when virus was treated with 1:2,000 and 1:3,000 dilutions of the oil, respectively. This was not due to a decrease in HA activity, as HA was preserved despite oil treatment. In addition, oil treatment did not affect virus binding or internalization in MDCK cells. These effects did not appear to be due to cytotoxicity of the oil as MDCK cell

  8. Noninvasive and label-free determination of virus infected cells by Raman spectroscopy

    Science.gov (United States)

    Moor, Kamila; Ohtani, Kiyoshi; Myrzakozha, Diyas; Zhanserkenova, Orik; Andriana, Bibin. B.; Sato, Hidetoshi

    2014-06-01

    The present study demonstrates that Raman spectroscopy is a powerful tool for the detection of virus-infected cells. Adenovirus infection of human embryonic kidney 293 cells was successfully detected at 12, 24, and 48 h after initiating the infection. The score plot of principal component analysis discriminated the spectra of the infected cells from those of the control cells. The viral infection was confirmed by the conventional immunostaining method performed 24 h after the infection. The newly developed method provides a fast and label-free means for the detection of virus-infected cells.

  9. Relative ultraviolet radiation sensitivity of certain functions of polyoma virus. Stimulation of cell DNA synthesis

    International Nuclear Information System (INIS)

    Peritoneal Mouse macrophages were used to study the stimulation of cell DNA synthesis by polyoma virus. Using ultraviolet-irradiated polyoma virus, it was possible to show a difference between the inactivation of infectivity and of induction of DNA synthesis. By statistical analysis of these two phenomena it was found that 39% of the viral genome is necessary for the induction of cell DNA synthesis

  10. BK virus-associated hemorrhagic cystitis after pediatric stem cell transplantation

    OpenAIRE

    Han, Seung Beom; Cho, Bin; Kang, Jin Han

    2014-01-01

    Hemorrhagic cystitis is a common stem cell transplantation-related complication. The incidence of early-onset hemorrhagic cystitis, which is related to the pretransplant conditioning regimen, has decreased with the concomitant use of mesna and hyperhydration. However, late-onset hemorrhagic cystitis, which is usually caused by the BK virus, continues to develop. Although the BK virus is the most common pathogenic microorganism of poststem cell transplantation late-onset hemorrhagic cystitis, ...

  11. Changes in protein phosphorylation in Rous sarcoma virus-transformed chicken embryo cells.

    OpenAIRE

    Cooper, J A; Hunter, T

    1981-01-01

    Rous sarcoma virus encodes a tyrosine-specific protein kinase (p60src) which is necessary for cell transformation. To identify substrates for this kinase, we set out to detect phosphotyrosine-containing proteins in Rous sarcoma virus-transformed chicken embryo cells, making use of the known alkali stability of phosphotyrosine. 32P-labeled phosphoproteins were separated by isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The gels were then incubated in alkali...

  12. Ebola Virus Disease in Mice with Transplanted Human Hematopoietic Stem Cells

    OpenAIRE

    Lüdtke, Anja; Oestereich, Lisa; Ruibal, Paula; Wurr, Stephanie; Pallasch, Elisa; Bockholt, Sabrina; Ip, Wing Hang; Rieger, Toni; Gómez-Medina, Sergio; Stocking, Carol; Rodríguez, Estefanía; Günther, Stephan; Muñoz-Fontela, César

    2015-01-01

    The development of treatments for Ebola virus disease (EVD) has been hampered by the lack of small-animal models that mimick human disease. Here we show that mice with transplanted human hematopoetic stem cells reproduce features typical of EVD. Infection with Ebola virus was associated with viremia, cell damage, liver steatosis, signs of hemorrhage, and high lethality. Our study provides a small-animal model with human components for the development of EVD therapies.

  13. Ebola virus disease in mice with transplanted human hematopoietic stem cells.

    Science.gov (United States)

    Lüdtke, Anja; Oestereich, Lisa; Ruibal, Paula; Wurr, Stephanie; Pallasch, Elisa; Bockholt, Sabrina; Ip, Wing Hang; Rieger, Toni; Gómez-Medina, Sergio; Stocking, Carol; Rodríguez, Estefanía; Günther, Stephan; Muñoz-Fontela, César

    2015-04-01

    The development of treatments for Ebola virus disease (EVD) has been hampered by the lack of small-animal models that mimick human disease. Here we show that mice with transplanted human hematopoetic stem cells reproduce features typical of EVD. Infection with Ebola virus was associated with viremia, cell damage, liver steatosis, signs of hemorrhage, and high lethality. Our study provides a small-animal model with human components for the development of EVD therapies. PMID:25673711

  14. Cell tropism predicts long-term nucleotide substitution rates of mammalian RNA viruses.

    Directory of Open Access Journals (Sweden)

    Allison L Hicks

    2014-01-01

    Full Text Available The high rates of RNA virus evolution are generally attributed to replication with error-prone RNA-dependent RNA polymerases. However, these long-term nucleotide substitution rates span three orders of magnitude and do not correlate well with mutation rates or selection pressures. This substitution rate variation may be explained by differences in virus ecology or intrinsic genomic properties. We generated nucleotide substitution rate estimates for mammalian RNA viruses and compiled comparable published rates, yielding a dataset of 118 substitution rates of structural genes from 51 different species, as well as 40 rates of non-structural genes from 28 species. Through ANCOVA analyses, we evaluated the relationships between these rates and four ecological factors: target cell, transmission route, host range, infection duration; and three genomic properties: genome length, genome sense, genome segmentation. Of these seven factors, we found target cells to be the only significant predictors of viral substitution rates, with tropisms for epithelial cells or neurons (P<0.0001 as the most significant predictors. Further, one-tailed t-tests showed that viruses primarily infecting epithelial cells evolve significantly faster than neurotropic viruses (P<0.0001 and P<0.001 for the structural genes and non-structural genes, respectively. These results provide strong evidence that the fastest evolving mammalian RNA viruses infect cells with the highest turnover rates: the highly proliferative epithelial cells. Estimated viral generation times suggest that epithelial-infecting viruses replicate more quickly than viruses with different cell tropisms. Our results indicate that cell tropism is a key factor in viral evolvability.

  15. Small Tumor Virus Genomes Are Integrated near Nuclear Matrix Attachment Regions in Transformed Cells

    OpenAIRE

    Shera, Katherine A.; Shera, Christopher A.; McDougall, James K

    2001-01-01

    More than 15% of human cancers have a viral etiology. In benign lesions induced by the small DNA tumor viruses, viral genomes are typically maintained extrachromosomally. Malignant progression is often associated with viral integration into host cell chromatin. To study the role of viral integration in tumorigenesis, we analyzed the positions of integrated viral genomes in tumors and tumor cell lines induced by the small oncogenic viruses, including the high-risk human papillomaviruses, hepat...

  16. Virus-Free Human Placental Cell Lines To Study Genetic Functions | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    The National Institute of Child Health and Human Development's Section on Cellular Differentiation is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate, or commercialize immortalized virus-free human placental cell lines.The National Institute of Child Health and Human Development's Section on Cellular Differentiation is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate, or commercialize immortalized virus-free human placental cell lines.

  17. Intravascularly Administered RGD-Displaying Measles Viruses Bind to and Infect Neovessel Endothelial Cells In Vivo

    OpenAIRE

    Ong, Hooi Tin; Trejo, Theodore R; Pham, Linh D.; Oberg, Ann L.; Russell, Stephen J.; Peng, Kah-Whye

    2009-01-01

    Systemically administered vectors must cross the endothelial lining of tumor blood vessels to access cancer cells. Vectors that interact with markers on the lumenal surface of these endothelial cells might have enhanced tumor localization. Here, we generated oncolytic measles viruses (MVs) displaying αvβ3 integrin-binding peptides, cyclic arginine-glycine-aspartate (RGD) or echistatin, on the measles hemagglutinin protein. Both viruses had expanded tropisms, and efficiently entered target cel...

  18. Rabies virus nucleoprotein expressed in and purified from insect cells is efficacious as a vaccine.

    OpenAIRE

    Fu, Z. F.; Dietzschold, B.; Schumacher, C L; Wunner, W H; Ertl, H. C.; Koprowski, H

    1991-01-01

    A cDNA copy of the RNA gene that encodes the nucleoprotein N of rabies virus Evelyn-Rokitnicki-Abelseth strain was cloned into baculovirus. The recombinant baculovirus expressed the N protein abundantly in Spodoptera frugiperda cells. The N protein was extracted from infected Spodoptera frugiperda cells and purified to near homogeneity by affinity chromatography. The purified N protein reacted with 31 of 32 monoclonal antibodies that recognize native rabies virus ribonucleoprotein. Like the r...

  19. Fucolipid metabolism as a function of cell population density in normal and murine sarcoma virus-transformed rat cells

    International Nuclear Information System (INIS)

    The incorporation of isotopically labeled fucose into the lipids of normal and murine sarcoma virus-transformed rat cells as a function of cell population density was examined. When normal cells were seeded at low cell density, the levels of the major fucolipids, i.e., fucolipids III and IV, were substantially reduced, but then they increased as the cells approached confluency. This variation in synthesis of fucolipids III and IV appeared to be primarily related to cell density and not to cell growth. Chase experiments revealed that the reduced level of fucolipids III and IV in sparse normal cells is due to decreased synthesis rather than to increased catabolism. In contrast to the observations with normal rat cells, the high level of fucolipid III and the low level of fucolipid IV in murine sarcoma virus-transformed rat cells was shown to be independent of cell population density

  20. HumanViCe: Host ceRNA network in virus infected cells in human

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    Suman eGhosal

    2014-07-01

    Full Text Available Host-virus interaction via host cellular components has been an important field of research in recent times. RNA interference mediated by short interfering RNAs and microRNAs (miRNA, is a widespread anti-viral defence strategy. Importantly, viruses also encode their own miRNAs. In recent times miRNAs were identified as key players in host-virus interaction. Furthermore, viruses were shown to exploit the host miRNA networks to suite their own need. The complex cross-talk between host and viral miRNAs and their cellular and viral targets forms the environment for viral pathogenesis. Apart from protein-coding mRNAs, non-coding RNAs may also be targeted by host or viral miRNAs in virus infected cells, and viruses can exploit the host miRNA mediated gene regulatory network via the competing endogenous RNA effect. A recent report showed that viral U-rich non-coding RNAs called HSUR, expressed in primate virus herpesvirus saimiri (HVS infected T cells, were able to bind to three host miRNAs, causing significant alteration in cellular level for one of the miRNAs. We have predicted protein coding and non protein-coding targets for viral and human miRNAs in virus infected cells. We identified viral miRNA targets within host non-coding RNA loci from AGO interacting regions in three different virus infected cells. Gene ontology (GO and pathway enrichment analysis of the genes comprising the ceRNA networks in the virus infected cells revealed enrichment of key cellular signalling pathways related to cell fate decisions and gene transcription, like Notch and Wnt signalling pathways, as well as pathways related to viral entry, replication and virulence. We identified a vast number of non-coding transcripts playing as potential ceRNAs to the immune response associated genes; e.g. APOBEC family genes, in some virus infected cells. All these information are compiled in HumanViCe, a comprehensive database that provides the potential ceRNA networks in virus

  1. Engineered defective interfering RNAs of Sindbis virus express bacterial chloramphenicol acetyltransferase in avian cells.

    OpenAIRE

    Levis, R; Huang, H.; Schlesinger, S

    1987-01-01

    We are investigating the feasibility of using the positive-strand RNA virus Sindbis virus and its defective interfering (DI) particles as vectors for introducing foreign genes into cells. In previous work we showed by deletion mapping of a cloned cDNA derived from one of the DI RNAs that only nucleotides at the 3' and 5' termini of the RNA are essential for the DI RNA to be amplified after it is transfected into cells in the presence of helper virus. As a first step in developing a vector we ...

  2. Metabolic stress in infected cells may represent a therapeutic target for human immunodeficiency virus infection.

    Science.gov (United States)

    Alonso-Villaverde, Carlos; Menéndez, Javier A; Joven, Jorge

    2013-07-01

    Worldwide, there are thousands of new cases of human immunodeficiency virus-1 (HIV-1) infection per day. The effectiveness of current combination antiretroviral therapy (ART) is relative; to prioritize finding vaccines and/or cure-oriented initiatives should be reinforced because there is little room, if any, for procrastination. Basic and clinical findings on HIV-1 reservoirs suggest that disruption of virus latency is feasible. Because the goal is curing HIV-1 infection, we should be aware that the challenge is to eradicate the viruses of every single infected cell and consequently acting upon virus latency is necessary but not sufficient. The large majority of the virus reservoir, CD4(+) T lymphocytes, is readily accessible but other minor reservoirs, where ART does not diffuse, require innovative strategies. The situation closely resembles that currently faced in the treatment of cancer. Exploiting the fact that histone deacetylase inhibitors, mainly vorinostat, may disrupt the latency of HIV-1, we propose to supplement this effect with a programmed interference in the metabolic stress of infected cells. Metformin and chloroquine are cheap and accessible modulators of pro-survival mechanisms to which viruses are constantly confronted to generate alternative energy sources and maximize virus production. Metformin restrains the use of the usurped cellular biosynthetic machinery by viral genes and chloroquine contributes to death of infected cells. We suggest that the combination of vorinostat, chloroquine and metformin should be combined with ART to pursue viral eradication in infected cells. PMID:23639282

  3. Development of avian sarcoma and leukosis virus-based vector-packaging cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Stoker, A.W.; Bissell, M.J. (Univ. of California, Berkeley (USA))

    1988-03-01

    The authors have constructed an avian leukosis virus derivative with a 5{prime} deletion extending from within the tRNA primer binding site to a SacI site in the leader region. The aim was to remove cis-acting replicative and/or encapsidation sequences and to use this derivative, RAV-1{Psi}{sup {minus}}, to develop vector-packaging cell lines. They show that RAV-1{Psi}{sup {minus}} can be stably expressed in the quail cell line QT6 and chicken embryo fibroblasts and that it is completely replication deficient in both cell types. Moreover, they have demonstrated that QT6-derived lines expressing RAV-1{Psi}{sup {minus}} can efficiently package four structurally different replication-defective v-src expression vectors into infectious virus, with very low or undetectable helper virus release. These RAV-{Psi}{sup {minus}}-expressing cell lines comprise the first prototype avian sarcoma and leukosis virus-based vector-packaging system. The construction of our vectors has also shown us that a sequence present within gag, thought to facilitate virus packaging, is not necessary for efficient vector expression and high virus production. They show that quantitation and characterization of replication-defective viruses can be achieved with a sensitive immunocytochemical procedure, presenting an alternative to internal selectable vector markers.

  4. Permissivity of the NCI-60 cancer cell lines to oncolytic Vaccinia Virus GLV-1h68

    Directory of Open Access Journals (Sweden)

    Bedognetti Davide

    2011-10-01

    Full Text Available Abstract Background Oncolytic viral therapy represents an alternative therapeutic strategy for the treatment of cancer. We previously described GLV-1h68, a modified Vaccinia Virus with exclusive tropism for tumor cells, and we observed a cell line-specific relationship between the ability of GLV-1h68 to replicate in vitro and its ability to colonize and eliminate tumor in vivo. Methods In the current study we surveyed the in vitro permissivity to GLV-1h68 replication of the NCI-60 panel of cell lines. Selected cell lines were also tested for permissivity to another Vaccinia Virus and a vesicular stomatitis virus (VSV strain. In order to identify correlates of permissity to viral infection, we measured transcriptional profiles of the cell lines prior infection. Results We observed highly heterogeneous permissivity to VACV infection amongst the cell lines. The heterogeneity of permissivity was independent of tissue with the exception of B cell derivation. Cell lines were also tested for permissivity to another Vaccinia Virus and a vesicular stomatitis virus (VSV strain and a significant correlation was found suggesting a common permissive phenotype. While no clear transcriptional pattern could be identified as predictor of permissivity to infection, some associations were observed suggesting multifactorial basis permissivity to viral infection. Conclusions Our findings have implications for the design of oncolytic therapies for cancer and offer insights into the nature of permissivity of tumor cells to viral infection.

  5. Permissivity of the NCI-60 cancer cell lines to oncolytic Vaccinia Virus GLV-1h68

    International Nuclear Information System (INIS)

    Oncolytic viral therapy represents an alternative therapeutic strategy for the treatment of cancer. We previously described GLV-1h68, a modified Vaccinia Virus with exclusive tropism for tumor cells, and we observed a cell line-specific relationship between the ability of GLV-1h68 to replicate in vitro and its ability to colonize and eliminate tumor in vivo. In the current study we surveyed the in vitro permissivity to GLV-1h68 replication of the NCI-60 panel of cell lines. Selected cell lines were also tested for permissivity to another Vaccinia Virus and a vesicular stomatitis virus (VSV) strain. In order to identify correlates of permissity to viral infection, we measured transcriptional profiles of the cell lines prior infection. We observed highly heterogeneous permissivity to VACV infection amongst the cell lines. The heterogeneity of permissivity was independent of tissue with the exception of B cell derivation. Cell lines were also tested for permissivity to another Vaccinia Virus and a vesicular stomatitis virus (VSV) strain and a significant correlation was found suggesting a common permissive phenotype. While no clear transcriptional pattern could be identified as predictor of permissivity to infection, some associations were observed suggesting multifactorial basis permissivity to viral infection. Our findings have implications for the design of oncolytic therapies for cancer and offer insights into the nature of permissivity of tumor cells to viral infection

  6. Persistent productive infection of human glial cells by human immunodeficiency virus (HIV) and by infectious molecular clones of HIV.

    OpenAIRE

    Dewhurst, S; Sakai, K.; de Bresser, J.; Stevenson, M.; Evinger-Hodges, M J; Volsky, D J

    1987-01-01

    The nature of the interaction between human immunodeficiency virus (HIV) and human cells of astrocytic origin was studied in vitro with cultured glial cells and intact HIV or infectious molecular clones of the virus. Infection of glial cells with intact HIV was characterized by low-level expression of viral transcripts as detected by Northern blotting and in situ hybridization (less than 10 copies of HIV RNA per cell), transient virus replication, absence of viral antigens detectable by immun...

  7. Genetic recombination of Herpes simplex virus, the role of the host cell and UV-irradiation of the virus

    International Nuclear Information System (INIS)

    Recombination frequencies for two sets of genetic markers of Herpes simplex virus were determined in various host cells with and without ultraviolet irradiation of the virus. UV irradiation increased the recombination frequency in all the cell types studied in direct proportion to the unrepaired lethal damage. In human skin fibroblasts derived from a patient with xeroderma pigmentosum (XP) of complementation group A, a given dose of UV stimulated recombination more than that in fibroblasts from normal individuals. On the other hand, UV stimulation of HSV recombination was slightly less than normal in fibroblasts derived from a patient with a variant form XP and from an ataxia telangiectasia patient. Caffeine, an agent known to inhibit repair of UV damage, reduced recombination in most of the cell types studied but did not suppress the UV-induced increase in recombination. These findings suggest that for virus DNA with the same number of unrepaired UV-lesions, each of the tested cell types promoted HSV-recombination to an equivalent extent. (orig.)

  8. Tissue tropism of simian immunodeficiency virus in rhesus monkeys

    International Nuclear Information System (INIS)

    Simian immunodeficiency virus (SIV) is a T-lymphotropic lentivirus that is genetically, immunologically, and morphologically related to the human immunodeficiency viruses type 1 and 2 (HIV-1, HIV-2). In rhesus monkeys, SIV induces a progressively fatal immunodeficiency syndrome strikingly similar to human acquired immunodeficiency syndrome (AIDS). The tissue and cellular tropism of SIV was determined by immunocytochemistry and in situ hybridization using a 3.48 kilobase SIV envelope gene probe labeled with biotin, 35S, or 3H. Probes labeled with 35S nonspecifically bound to tissue eosinophils and produced poor signal resolution compared to tritium labeled probes. Biotin labeled probes did not detect SIV under similar hybridization conditions. Formalin-fixed, paraffin-embedded tissues produced strong hybridization signal with superior morphology compared to frozen tissues. Gastrointestinal, respiratory, and lymphoid tissues most frequently contained SIV RNA. The distribution of SIV did not correlate with sex, or viral inoculum, but was most extensive in animals with SIV induced granulomatous encephalitis. SIV was most frequently observed in lymphocytes and macrophages. In the brain focal granulomas were composed almost entirely of EBM11+, lysozyme+, macrophages which contained large amounts of SIV RNA and p27 core protein detected by the monoclonal antibody R1C7. Cells away from granulomas in the brain parenchyma and around blood vessels contained virus and were compatible with oligodendrocytes and astrocytes. Lymph nodes in follicular hyperplasia contained small numbers of SIV positive cells compatible with lymphocytes in the paracortex and mantle zones as well as in cells of the germinal center. Lymph nodes in various stages of follicular depletion with expanded paracortices contained large numbers of cells with SIV RNA in lymphocytes and macrophages

  9. Venezuelan equine encephalitis virus entry mechanism requires late endosome formation and resists cell membrane cholesterol depletion

    International Nuclear Information System (INIS)

    Virus envelope proteins determine receptor utilization and host range. The choice of receptor not only permits specific targeting of cells that express it, but also directs the virus into specific endosomal trafficking pathways. Disrupting trafficking can result in loss of virus infectivity due to redirection of virions to non-productive pathways. Identification of the pathway or pathways used by a virus is, thus, important in understanding virus pathogenesis mechanisms and for developing new treatment strategies. Most of our understanding of alphavirus entry has focused on the Old World alphaviruses, such as Sindbis and Semliki Forest virus. In comparison, very little is known about the entry route taken by more pathogenic New World alphaviruses. Here, we use a novel contents mixing assay to identify the cellular requirements for entry of a New World alphavirus, Venezuelan equine encephalitis virus (VEEV). Expression of dominant negative forms of key endosomal trafficking genes shows that VEEV must access clathrin-dependent endocytic vesicles for membrane fusion to occur. Unexpectedly, the exit point is different from Old World alphaviruses that leave from early endosomes. Instead, VEEV also requires functional late endosomes. Furthermore, unlike the Old World viruses, VEEV entry is insensitive to cholesterol sequestration from cell membranes and may reflect a need to access an endocytic compartment that lacks cholesterol. This indicates fundamental differences in the entry route taken by VEEV compared to Old World alphaviruses

  10. Giant cell arteritis associated with chronic active Epstein-Barr virus infection

    Directory of Open Access Journals (Sweden)

    A. Giardina

    2013-03-01

    Full Text Available Giant cell arteritis is an inflammatory vasculopathy that preferentially affects medium-sized and large arteries. A viral cause has been suspected but not confirmed in polymyalgia rheumatica and giant-cell arteritis. We report the case of a 81-year-old female who suffered from chronic active Epstein-Barr virus infection and developed giant cell temporal arteritis.

  11. Determination of suitable housekeeping genes for normalisation of quantitative real time PCR analysis of cells infected with human immunodeficiency virus and herpes viruses

    Directory of Open Access Journals (Sweden)

    Wilkinson John

    2007-12-01

    Full Text Available Abstract The choice of an appropriate housekeeping gene for normalisation purposes has now become an essential requirement when designing QPCR experiments. This is of particular importance when using QPCR to measure viral and cellular gene transcription levels in the context of viral infections as viruses can significantly interfere with host cell pathways, the components of which traditional housekeeping genes often encode. In this study we have determined the reliability of 10 housekeeping genes in context of four heavily studied viral infections; human immunodeficiency virus type 1, herpes simplex virus type 1, cytomegalovirus and varicella zoster virus infections using a variety of cell types and virus strains. This provides researchers of these viruses with a shortlist of potential housekeeping genes to use as normalisers for QPCR experiments.

  12. Comparative Pathogenicity of Liver Homogenate and Cell Culture Propagated Hydropericardium Syndrome Virus in Broiler Birds

    Directory of Open Access Journals (Sweden)

    M. D. Ahmad, S. Zaman1, M. H. Mushtaq*, A. A. Anjum1 and M. Akram1

    2011-10-01

    Full Text Available Comparative pathogenicity of liver homogenate and cell culture propagated agents of hydropericardium syndrome was studied in broiler birds. In Experiment I, 25-day-old while in experiment II, broiler birds at different ages were inoculated through different routes. In Experiment I, liver homogenate caused 64% mortality through intramuscular route and 33.33% mortality through oral route. The cell culture propagated HPS virus caused 60 and 13.33% mortality in broiler birds through intramuscular and oral routes, respectively. In Experiment II, none of the day-old-chicks died when challenged with liver homogenate and cell culture propagated HPS virus through S/C and oral route. The liver homogenate and cell culture propagated HPS virus caused higher mortality in different age groups of broiler birds through s/c route compared to oral route. The values of hemoglobin (Hb and packed cell volume (PCV showed highly significant (P<0.05 reduction indicating anemia. The values of Hb and PCV of the broiler birds inoculated with infectious liver homogenate were significantly lower as compared to birds inoculated with cell culture propagated HPS virus. The results indicated that the liver homogenate is more pathogenic than cell culture propagated HPS virus. These changes may be due to adoptability of the original FAdVs (fowl adenovirus after continued passages in the culture of chicken embryo liver cells. Importance of this study in vaccine production is also discussed.

  13. How antibodies alter the cell entry pathway of dengue virus particles in macrophages

    Science.gov (United States)

    Ayala-Nunez, Nilda V.; Hoornweg, Tabitha E.; van de Pol, Denise P.I.; Sjollema, Klaas A.; Flipse, Jacky; van der Schaar, Hilde M.; Smit, Jolanda M.

    2016-01-01

    Antibody-dependent enhancement of dengue virus (DENV) infection plays an important role in the exacerbation of DENV-induced disease. To understand how antibodies influence the fate of DENV particles, we explored the cell entry pathway of DENV in the absence and presence of antibodies in macrophage-like P388D1 cells. Recent studies unraveled that both mature and immature DENV particles contribute to ADE, hence, both particles were studied. We observed that antibody-opsonized DENV enters P388D1 cells through a different pathway than non-opsonized DENV. Antibody-mediated DENV entry was dependent on FcγRs, pH, Eps15, dynamin, actin, PI3K, Rab5, and Rab7. In the absence of antibodies, DENV cell entry was FcγR, PI3K, and Rab5-independent. Live-cell imaging of fluorescently-labeled particles revealed that actin-mediated membrane protrusions facilitate virus uptake. In fact, actin protrusions were found to actively search and capture antibody-bound virus particles distantly located from the cell body, a phenomenon that is not observed in the absence of antibodies. Overall, similar results were seen for antibody-opsonized standard and antibody-bound immature DENV preparations, indicating that the maturation status of the virus does not control the entry pathway. Collectively, our findings suggest that antibodies alter the cell entry pathway of DENV and trigger a novel mechanism of initial virus-cell contact. PMID:27385443

  14. A generic screening platform for inhibitors of virus induced cell fusion using cellular electrical impedance.

    Science.gov (United States)

    Watterson, Daniel; Robinson, Jodie; Chappell, Keith J; Butler, Mark S; Edwards, David J; Fry, Scott R; Bermingham, Imogen M; Cooper, Matthew A; Young, Paul R

    2016-01-01

    Fusion of the viral envelope with host cell membranes is an essential step in the life cycle of all enveloped viruses. Despite such a clear target for antiviral drug development, few anti-fusion drugs have progressed to market. One significant hurdle is the absence of a generic, high-throughput, reproducible fusion assay. Here we report that real time, label-free measurement of cellular electrical impedance can quantify cell-cell fusion mediated by either individually expressed recombinant viral fusion proteins, or native virus infection. We validated this approach for all three classes of viral fusion and demonstrated utility in quantifying fusion inhibition using antibodies and small molecule inhibitors specific for dengue virus and respiratory syncytial virus. PMID:26976324

  15. Mass spectrometric analysis of host cell proteins interacting with dengue virus nonstructural protein 1 in dengue virus-infected HepG2 cells.

    Science.gov (United States)

    Dechtawewat, Thanyaporn; Paemanee, Atchara; Roytrakul, Sittiruk; Songprakhon, Pucharee; Limjindaporn, Thawornchai; Yenchitsomanus, Pa-Thai; Saitornuang, Sawanan; Puttikhunt, Chunya; Kasinrerk, Watchara; Malasit, Prida; Noisakran, Sansanee

    2016-09-01

    Dengue virus (DENV) infection is a leading cause of the mosquito-borne infectious diseases that affect humans worldwide. Virus-host interactions appear to play significant roles in DENV replication and the pathogenesis of DENV infection. Nonstructural protein 1 (NS1) of DENV is likely involved in these processes; however, its associations with host cell proteins in DENV infection remain unclear. In this study, we used a combination of techniques (immunoprecipitation, in-solution trypsin digestion, and LC-MS/MS) to identify the host cell proteins that interact with cell-associated NS1 in an in vitro model of DENV infection in the human hepatocyte HepG2 cell line. Thirty-six novel host cell proteins were identified as potential DENV NS1-interacting partners. A large number of these proteins had characteristic binding or catalytic activities, and were involved in cellular metabolism. Coimmunoprecipitation and colocalization assays confirmed the interactions of DENV NS1 and human NIMA-related kinase 2 (NEK2), thousand and one amino acid protein kinase 1 (TAO1), and component of oligomeric Golgi complex 1 (COG1) proteins in virus-infected cells. This study reports a novel set of DENV NS1-interacting host cell proteins in the HepG2 cell line and proposes possible roles for human NEK2, TAO1, and COG1 in DENV infection. PMID:27108190

  16. Modeling HIV-1 Latency in Primary T Cells Using a Replication-Competent Virus.

    Science.gov (United States)

    Martins, Laura J; Bonczkowski, Pawel; Spivak, Adam M; De Spiegelaere, Ward; Novis, Camille L; DePaula-Silva, Ana Beatriz; Malatinkova, Eva; Typsteen, Wim; Bosque, Alberto; Vanderkerckhove, Linos; Planelles, Vicente

    2016-02-01

    HIV-1 latently infected cells in vivo can be found in extremely low frequencies. Therefore, in vitro cell culture models have been used extensively for the study of HIV-1 latency. Often, these in vitro systems utilize defective viruses. Defective viruses allow for synchronized infections and circumvent the use of antiretrovirals. In addition, replication-defective viruses cause minimal cytopathicity because they fail to spread and usually do not encode env or accessory genes. On the other hand, replication-competent viruses encode all or most viral genes and better recapitulate the nuances of the viral replication cycle. The study of latency with replication-competent viruses requires the use of antiretroviral drugs in culture, and this mirrors the use of antiretroviral treatment (ART) in vivo. We describe a model that utilizes cultured central memory CD4(+) T cells and replication-competent HIV-1. This method generates latently infected cells that can be reactivated using latency reversing agents in the presence of antiretroviral drugs. We also describe a method for the removal of productively infected cells prior to viral reactivation, which takes advantage of the downregulation of CD4 by HIV-1, and the use of a GFP-encoding virus for increased throughput. PMID:26171776

  17. Enhanced replication of herpes simplex virus type 1 in human cells

    International Nuclear Information System (INIS)

    The effects of DNA-damaging agents on the replication of herpes simplex virus type 1 (HSV-1) were assessed in vitro. Monolayers of human lung fibroblast cell lines were exposed to DNA-damaging agents (methyl methanesulfonate [MMS], methyl methanethiosulfonate [MMTS], ultraviolet light [UV], or gamma radiation [GR]) at specific intervals, before or after inoculation with low levels of HSV-1. The ability of cell monolayers to support HSV-1 replication was measured by direct plaque assay and was compared with that of untreated control samples. In this system, monolayers of different cell lines infected with identical HSV-1 strains demonstrated dissimilar levels of recovery of the infectious virus. Exposure of DNA-repair-competent cell cultures to DNA-damaging agents produced time-dependent enhanced virus replication. Treatment with agent before virus inoculation significantly (p less than 0.025) increased the number of plaques by 10 to 68%, compared with untreated control cultures, while treatment with agent after virus adsorption significantly increased (p less than 0.025) the number of plaques by 7 to 15%. In a parallel series of experiments, cells deficient in DNA repair (xeroderma pigmentosum) failed to support enhanced virus replication. These results suggest that after exposure to DNA-damaging agents, fibroblasts competent in DNA repair amplify the replication of HSV-1, and that DNA-repair mechanisms that act on a variety of chromosomal lesions may be involved in the repair and biological activation of HSV-1 genomes

  18. Monkeypox Virus Infection of Rhesus Macaques Induces Massive Expansion of Natural Killer Cells but Suppresses Natural Killer Cell Functions

    OpenAIRE

    Song, Haifeng; Josleyn, Nicole; Janosko, Krisztina; Skinner, Jeff; Reeves, R. Keith; Cohen, Melanie; Jett, Catherine; Johnson, Reed; Blaney, Joseph E.; Bollinger, Laura; Jennings, Gerald; Jahrling, Peter B

    2013-01-01

    Natural killer (NK) cells play critical roles in innate immunity and in bridging innate and adaptive immune responses against viral infection. However, the response of NK cells to monkeypox virus (MPXV) infection is not well characterized. In this intravenous challenge study of MPXV infection in rhesus macaques (Macaca mulatta), we analyzed blood and lymph node NK cell changes in absolute cell numbers, cell proliferation, chemokine receptor expression, and cellular functions. Our results show...

  19. Quantitation, in vitro propagation, and characterization of preleukemic cells induced by radiation leukemia virus

    International Nuclear Information System (INIS)

    Intrathymic (i.t.) inoculation of radiation leukemia virus into C57BL/6 mice induces a population of preleukemic (PL) cells that can progress into mature thymic lymphomas upon transfer into syngeneic recipients. A minimum of 10(3) PL thymic cells are required to induce lymphomas in the recipient. Most of the individual lymphomas developed in mice which were inoculated with cells of a single PL thymus, derived from different T-cell precursors. PL thymic cells could be grown in vitro on a feeder layer consisting of splenic stromal cells. Growth medium was supplemented with supernatant harvested from an established radiation leukemia virus-induced lymphoma cell line (SR4). The in vitro-grown PL cells were characterized as Thy-1+, CD4+, CD8- T-cells, most of which expressed radiation leukemia virus antigens. Cultured PL cells were found to be nontumorigenic, based on their inability to form s.c. tumors. However, these cells could develop into thymic lymphomas if inoculated i.t. into syngeneic recipients. A culture of PL cells, maintained for 2 mo, showed clonal T-cell receptor arrangement. Lymphomas which developed in several recipient mice upon injection with these PL cells were found to possess the same T-cell receptor arrangement. These results indicate that PL cells can be adapted for in vitro growth while maintaining their preleukemic character

  20. Use of chicken cell line LSCC-H32 for titration of animal viruses and exogenous chicken interferon.

    OpenAIRE

    Roth, S.; Kaaden, O R

    1985-01-01

    The chicken embryo cell line LSCC-H32 was tested for the propagation and titration of several animal viruses of the families Toga-, Reo-, Rhabdo-, Herpeto-, Orthomyxo-, Paramyxo-, and Poxviridae and compared with secondary chicken embryo cells. The LSCC-H32 cells were demonstrated to be as susceptible for most of the tested viruses as were secondary chicken embryo cells. Both produced comparably sized virus plaques. The titers of Sindbis and Semliki Forest viruses in LSCC-H32 cells were 5- to...

  1. Caveolae Restrict Tiger Frog Virus Release in HepG2 cells and Caveolae-Associated Proteins Incorporated into Virus Particles

    OpenAIRE

    Jian He; Yi-Wen Zheng; Yi-Fan Lin; Shu Mi; Xiao-Wei Qin; Shao-Ping Weng; Jian-Guo He; Chang-Jun Guo

    2016-01-01

    Caveolae are flask-shaped invaginations of the plasma membrane. Caveolae play important roles in the process of viruses entry into host cells, but the roles of caveolae at the late stage of virus infection were not completely understood. Tiger frog virus (TFV) has been isolated from the diseased tadpoles of the frog, Rana tigrina rugulosa, and causes high mortality of tiger frog tadpoles cultured in Southern China. In the present study, the roles of caveolae at the late stage of TFV infection...

  2. Melaleuca alternifolia Concentrate Inhibits in Vitro Entry of Influenza Virus into Host Cells

    Directory of Open Access Journals (Sweden)

    Lifang Jiang

    2013-08-01

    Full Text Available Influenza virus causes high morbidity among the infected population annually and occasionally the spread of pandemics. Melaleuca alternifolia Concentrate (MAC is an essential oil derived from a native Australian tea tree. Our aim was to investigate whether MAC has any in vitro inhibitory effect on influenza virus infection and what mechanism does the MAC use to fight the virus infection. In this study, the antiviral activity of MAC was examined by its inhibition of cytopathic effects. In silico prediction was performed to evaluate the interaction between MAC and the viral haemagglutinin. We found that when the influenza virus was incubated with 0.010% MAC for one hour, no cytopathic effect on MDCK cells was found after the virus infection and no immunofluorescence signal was detected in the host cells. Electron microscopy showed that the virus treated with MAC retained its structural integrity. By computational simulations, we found that terpinen-4-ol, which is the major bioactive component of MAC, could combine with the membrane fusion site of haemagglutinin. Thus, we proved that MAC could prevent influenza virus from entering the host cells by disturbing the normal viral membrane fusion procedure.

  3. Melaleuca alternifolia concentrate inhibits in vitro entry of influenza virus into host cells.

    Science.gov (United States)

    Li, Xinghua; Duan, Songwei; Chu, Cordia; Xu, Jun; Zeng, Gucheng; Lam, Alfred King-Yin; Zhou, Junmei; Yin, Yue; Fang, Danyun; Reynolds, Maxwell John; Gu, Huaiyu; Jiang, Lifang

    2013-01-01

    Influenza virus causes high morbidity among the infected population annually and occasionally the spread of pandemics. Melaleuca alternifolia Concentrate (MAC) is an essential oil derived from a native Australian tea tree. Our aim was to investigate whether MAC has any in vitro inhibitory effect on influenza virus infection and what mechanism does the MAC use to fight the virus infection. In this study, the antiviral activity of MAC was examined by its inhibition of cytopathic effects. In silico prediction was performed to evaluate the interaction between MAC and the viral haemagglutinin. We found that when the influenza virus was incubated with 0.010% MAC for one hour, no cytopathic effect on MDCK cells was found after the virus infection and no immunofluorescence signal was detected in the host cells. Electron microscopy showed that the virus treated with MAC retained its structural integrity. By computational simulations, we found that terpinen-4-ol, which is the major bioactive component of MAC, could combine with the membrane fusion site of haemagglutinin. Thus, we proved that MAC could prevent influenza virus from entering the host cells by disturbing the normal viral membrane fusion procedure. PMID:23966077

  4. Toso regulates differentiation and activation of inflammatory dendritic cells during persistence-prone virus infection.

    Science.gov (United States)

    Lang, P A; Meryk, A; Pandyra, A A; Brenner, D; Brüstle, A; Xu, H C; Merches, K; Lang, F; Khairnar, V; Sharma, P; Funkner, P; Recher, M; Shaabani, N; Duncan, G S; Duhan, V; Homey, B; Ohashi, P S; Häussinger, D; Knolle, P A; Honke, N; Mak, T W; Lang, K S

    2015-01-01

    During virus infection and autoimmune disease, inflammatory dendritic cells (iDCs) differentiate from blood monocytes and infiltrate infected tissue. Following acute infection with hepatotropic viruses, iDCs are essential for re-stimulating virus-specific CD8(+) T cells and therefore contribute to virus control. Here we used the lymphocytic choriomeningitis virus (LCMV) model system to identify novel signals, which influence the recruitment and activation of iDCs in the liver. We observed that intrinsic expression of Toso (Faim3, FcμR) influenced the differentiation and activation of iDCs in vivo and DCs in vitro. Lack of iDCs in Toso-deficient (Toso(-/-)) mice reduced CD8(+) T-cell function in the liver and resulted in virus persistence. Furthermore, Toso(-/-) DCs failed to induce autoimmune diabetes in the rat insulin promoter-glycoprotein (RIP-GP) autoimmune diabetes model. In conclusion, we found that Toso has an essential role in the differentiation and maturation of iDCs, a process that is required for the control of persistence-prone virus infection. PMID:25257173

  5. Synthesis of plus strands of retroviral DNA in cells infected with avian sarcoma virus and mouse mammary tumor virus.

    OpenAIRE

    Kung, H J; Fung, Y. K.; Majors, J E; Bishop, J M; Varmus, H E

    1981-01-01

    The vast majority of plus strands synthesized in quail cells acutely infected with avian sarcoma virus were subgenomic in size, generally less than 3 kilobases (kb). A series of discrete species could be identified after agarose gel electrophoresis by annealing with various complementary DNAs, indicating specificity in the initiation and termination of plus strands. The first plus strand to appear (within 2 h postinfection) was similar in length to the long redundancy at the ends of linear DN...

  6. Extensive cell heterogeneity during persistent infection with foot-and-mouth disease virus.

    OpenAIRE

    de la Torre, J C; Martínez-Salas, E; J. Díez; Domingo, E

    1989-01-01

    Coevolution of viruses and the host cells occurred in BHK-21 cell cultures persistently infected with foot-and-mouth disease virus (FMDV) (J. C. de la Torre, E. Martínez-Salas, J. Diez, A. Villaverde, F. Gebauer, E. Rocha, M. Dávila, and E. Domingo, J. Virol. 62:2050-2058, 1988). In the present report we provide evidence of an extreme phenotypic heterogeneity of the cells, which was generated in the course of persistence. A total of 248 stable cell clones isolated from FMDV carrier cultures a...

  7. Quantitative detection of Merkel Cell Virus in human tissues and possible mode of transmission

    OpenAIRE

    Loyo, M; Guerrero-Preston, R; Brait, M.; Hoque, MO; Chuang, A.; Kim, MS; SHARMA, R.; Liégeois, NJ; Koch, WM; Califano, J; Westra, WH; Sidransky, D.

    2010-01-01

    Merkel Cell Virus (MCV) is a newly discovered polyoma virus recently found in a rare skin cancer, Merkel cell carcinoma. However, MCV has also been detected in some normal tissue samples. We tested and compared the relative quantity of the MCV in a set of diverse human tissue samples with the Merkel cell carcinoma samples. The levels of MCV in Merkel cell carcinomas were over 60 times higher than the highest values in all other tissues. Low quantities of MCV were detected in diverse tissue sa...

  8. Asthma and influenza virus infection:focusing on cell death and stress pathways in influenza virus replication.

    Directory of Open Access Journals (Sweden)

    Behzad Yeganeh

    2013-03-01

    Full Text Available Asthma is one of the fastest growing syndromes in many countries and is adding a huge cost to the health care system. Increasing reports have linked airway infectious diseases to asthma. Influenza is one of the most serious airway infectious diseases and in recent years there have been some serious influenza virus pandemics which caused increased fatality in numerous different populations. Diverse host response pathways during virus infection have been identified, including different cell death and survival pathways. These pathways include1 programmed cell death I (apoptosis, 2 programmed cell death II (autophagy, and 3 endoplasmic reticulum stress with subsequent unfolded protein response (UPR. There has been extensive research on the regulatory roles of these pathways during the influenza virus life cycle. These studies address the benefits of enhancing or inhibiting these pathways on viral replication. Here we review the most recent and significant knowledge in this area for possible  benefits  to  clinicians and  basic  scientist researchers  in  different  areas  of  the respiratory and virology sciences.

  9. Human influenza A viruses are proteolytically activated and do not induce apoptosis in CACO-2 cells

    International Nuclear Information System (INIS)

    Replication of human influenza A/H3N2 and A/H1N1 viruses was studied in human CACO-2 cells, a continuous line of intestinal epithelial differentiated cells. Hemagglutinin (HA) was cleaved in these cells by an endogenous protease. Thus, infectious virus was produced that underwent multiple cycle replication and plaque formation in the absence of trypsin added to the media. Cleavage of de novo-synthesized HA occurred at a late stage of the exocytic pathway as indicated by pulse-chase labeling and by experiments employing endoglycosidase H and brefeldin A treatment. However, surface-labeling experiments employing biotinylation suggested that there is no cleavage at the plasma membrane. Unlike HA of serotypes H5 and H7 cleaved at multibasic cleavage sites by furin, the HAs with monobasic cleavage sites analyzed here were not cleaved in CACO-2 cells in the presence of aprotinin, a natural inhibitor of trypsinlike proteases. Growing CACO-2 cells were able to cleave HA of incoming virus, although influenza virus activating protease was not detected in culture medium. These observations indicate that the activating enzyme of CACO-2 cells is a trypsinlike protease functioning in the trans-Golgi network and presumably endosomes. In support of this concept immune staining with antibodies specific to human and bovine trypsin revealed the presence of a trypsinlike protease in CACO-2 cells. Unlike MDCK and CV-1 cells undergoing rapid apoptosis after influenza virus infection, CACO-2 cells showed no apoptosis but displayed cytopathic effects with necrotic signs significantly later after infection. It follows from these data that, depending on the cell type, influenza virus may kill cells either by apoptosis or by necrosis

  10. Serological responses in chimpanzees inoculated with human immunodeficiency virus glycoprotein (gp120) subunit vaccine

    International Nuclear Information System (INIS)

    The major envelope glycoprotein of a human immunodeficiency virus (HIV) has been purified and was utilized as a prototype vaccine in chimpanzees. The 120,000-dalton glycoprotein (gp120) was purified from membranes of human T-lymphotropic virus (HTLV)-IIIB-infected cells and the final preparation contained low levels to no detectable HTLV-IIIB core antigen (p24) and low levels of endotoxin. Chimpanzees inoculated with gp120 responded by developing antibodies that precipitated radiolabeled gp120 and neutralized in vitro infection of HTLV-IIIB. Antibodies to HTLV-IIIB p24 were not detected in the gp120-immunized chimpanzees. Peripheral blood leukocytes from the vaccinated animals were examined for T4+ and T8+ cells, and no decrease in the T4/T8 ratio was found, indicating that immunization with a ligand (gp120) that binds to T4 has not detectable adverse effect on the population of T4+ cells. The only current animal model that can be reproducibly infected with HIV is the chimpanzee. Immunization of chimpanzees with HIV proteins will provide an experimental system for testing the effectiveness of prototype vaccines for preventing HIV infection in vivo

  11. Serological responses in chimpanzees inoculated with human immunodeficiency virus glycoprotein (gp120) subunit vaccine

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, L.O.; Pyle, S.W.; Nara, P.L.; Bess, J.W. Jr.; Gonda, M.A.; Kelliher, J.C.; Gilden, R.V.; Robey, W.G.; Bolognesi, D.P.; Gallo, R.C.

    1987-12-01

    The major envelope glycoprotein of a human immunodeficiency virus (HIV) has been purified and was utilized as a prototype vaccine in chimpanzees. The 120,000-dalton glycoprotein (gp120) was purified from membranes of human T-lymphotropic virus (HTLV)-IIIB-infected cells and the final preparation contained low levels to no detectable HTLV-IIIB core antigen (p24) and low levels of endotoxin. Chimpanzees inoculated with gp120 responded by developing antibodies that precipitated radiolabeled gp120 and neutralized in vitro infection of HTLV-IIIB. Antibodies to HTLV-IIIB p24 were not detected in the gp120-immunized chimpanzees. Peripheral blood leukocytes from the vaccinated animals were examined for T4/sup +/ and T8/sup +/ cells, and no decrease in the T4/T8 ratio was found, indicating that immunization with a ligand (gp120) that binds to T4 has not detectable adverse effect on the population of T4/sup +/ cells. The only current animal model that can be reproducibly infected with HIV is the chimpanzee. Immunization of chimpanzees with HIV proteins will provide an experimental system for testing the effectiveness of prototype vaccines for preventing HIV infection in vivo.

  12. Measuring Attachment and Internalization of Influenza A Virus in A549 Cells by Flow Cytometry.

    Science.gov (United States)

    Pohl, Marie O; Stertz, Silke

    2015-01-01

    Attachment to target cells followed by internalization are the very first steps of the life cycle of influenza A virus (IAV). We provide here a detailed protocol for measuring relative changes in the amount of viral particles that attach to A549 cells, a human lung epithelial cell line, as well as in the amount of particles that are internalized into the cell. We use biotinylated virus which can be easily detected following staining with Cy3-labeled streptavidin (STV-Cy3). We describe the growth, purification and biotinylation of A/WSN/33, a widely used IAV laboratory strain. Cold-bound biotinylated IAV particles on A549 cells are stained with STV-Cy3 and measured using flow cytometry. To investigate uptake of viral particles, cold-bound virus is allowed to internalize at 37 °C. In order to differentiate between external and internalized viral particles, a blocking step is applied: Free binding spots on the biotin of attached virus on the cell surface are bound by unlabeled streptavidin (STV). Subsequent cell permeabilization and staining with STV-Cy3 then enables detection of internalized viral particles. We present a calculation to determine the relative amount of internalized virus. This assay is suitable to measure effects of drug-treatments or other manipulations on attachment or internalization of IAV. PMID:26575457

  13. A block in virus-like particle maturation following assembly of murine leukaemia virus in insect cells

    International Nuclear Information System (INIS)

    Expression of the murine leukaemia virus (MLV) major Gag antigen p65Gag using the baculovirus expression system leads to efficient assembly and release of virus-like particles (VLP) representative of immature MLV. Expression of p180Gag-Pol, facilitated normally in mammalian cells by readthrough of the p65Gag termination codon, also occurs efficiently in insect cells to provide a source of the MLV protease and a pattern of p65Gag processing similar to that observed in mammalian cells. VLP release from p180Gag-Pol-expressing cells however remains essentially immature with disproportionate levels of the uncleaved p65Gag precursor when compared to the intracellular Gag profile. Changing the p65Gag termination codon altered the level of p65Gag and p180Gag-Pol within expressing cells but did not alter the pattern of released VLP, which remained immature. Coexpression of p65Gag with a fixed readthrough p180Gag-Pol also led to only immature VLP release despite high intracellular protease levels. Our data suggest a mechanism that preferentially selects uncleaved p65Gag for the assembly of MLV in this heterologous expression system and implies that, in addition to their relative levels, active sorting of the correct p65Gag and p180Gag-Pol ratios may occur in producer cells

  14. Murine cellular cytotoxicity to syngeneic and xenogeneic herpes simplex virus-infected cells.

    Science.gov (United States)

    Kohl, S; Drath, D B; Loo, L S

    1982-12-01

    Cellular cytotoxicity of C57BL/6 adult mice peritoneal cells to xenogeneic (Chang liver) and syngeneic (BL/6-WT3) herpes simplex virus (HSV)-infected cells was analyzed in a 6-h 51Cr release assay. There was no difference in antibody-dependent cellular cytotoxicity to either target. There was no natural killer cytotoxicity to targets with cells from uninfected mice except at very high effector cell ratios. HSV-infected (2 X 10(4) PFU intraperitoneally 1 day previously) mice mediated significantly higher antibody-dependent cellular cytotoxicity and required less antibody (10(-5) versus 10(-2) dilution), fewer cells, and less time to kill than cells from uninfected mice. HSV-infected mice mediated natural killer cytotoxicity but preferentially killed syngeneic HSV-infected cells. Stimulation of cytotoxicity was not virus specific since influenza-infected mice mediated similar levels of cytotoxicity to HSV-infected targets. There was no difference in morphology (95% macrophage) or in the percentage of FcR-positive cells, but infected mice had more peritoneal cells and generated higher levels of superoxide in response to opsonized zymosan or phorbolmyristate acetate. These data demonstrate nonspecific virus-stimulated metabolic and effector cell function which may enhance clearance of virus in an infected host. PMID:6295943

  15. Preliminary study on Herpes simplex virus type 1 infection of human oral epithelial cell in vitro

    Institute of Scientific and Technical Information of China (English)

    Jie Zhao; Weibin Sun; Juan Wang

    2008-01-01

    Objective: To explore the functions and mechanisms of herpes simplex virus type 1(HSV-1) while infecting human oral epithelial cells in vitro(being similar to the infection in vivo). Methods:An abundance of HSV-1 strains amplified in Vero cells were used to infect human oral epithelial cells. The culture supernatant was collected to infect Veto cells again. Morphology of HSV-1 was identified by inverted microscope and transmission electron microscope. Nucleic acid of the virus was detected by PCR. Results:The infected human oral epithelial cells didn't display an obvious cytopathic effect(CPE) under inverted microscope(while Veto cells which were infected by the culture supematant showed typical(CPE). The virus particles were not observed in the cytoplasm nor in nucleus of human oral epithelial cells, however under transmission electron microscope in the cytoplasm of Vero cells, the nucleic acid of HSV-1 could be detected in infected human oral epithelial cells, by PCR. Conclusion:HSV-1 can successfully infect human oral epithelial cells. This model may provide a useful approach for studying the pathogenesis of herpes virus-associated periodontal disease.

  16. Comparative analysis of signature genes in porcine reproductive and respiratory syndrome virus (PRRSV)-infected porcine monocyte-derived dendritic cells at differential activation statuses

    Science.gov (United States)

    Activation statuses of monocytic cells, e.g. monocytes, macrophages and dendritic cells (DCs), are critically important for antiviral immunity. In particular, some devastating viruses, including porcine reproductive and respiratory syndrome virus (PRRSV), are capable of directly infecting these cell...

  17. Induction of virus-neutralizing antibodies and T cell responses by dengue virus type 1 virus-like particles prepared from Pichia pastoris

    Institute of Scientific and Technical Information of China (English)

    TANG Yun-xia; JIANG Li-fang; ZHOU Jun-mei; YIN Yue; YANG Xiao-meng; LIU Wen-quan; FANG Dan-yun

    2012-01-01

    Background Dengue is currently a significant global health problem but no vaccines are available against the four dengue serotypes virus infections.The development of safe and effective vaccines has been hampered by the requirement of conferring complete protection against all four dengue serotypes and the lack of a convenient animal model.Virus-like particles (VLPs) have emerged as a promising subunit vaccine candidate.One strategy of vaccine development is to produce a tetravalent dengue subunit vaccine by mixing recombinant VLPs,corresponding to all four dengue virus serotypes.Towards this end,this study aimed to establish a Pichia pastoris (P.pastoris) expression system for production of dengue virus type 1 (DENV-1) VLPs and evaluate the humoral and cellular immune response of this particle in mice.Methods A recombinant yeast P.pastoris clone containing prM and E genes of DENV-1 was constructed and DENV-1 VLPs expressed by this clone were analyzed by sucrose density gradient centrifugation,Western blotting,and transmission electron microscope.Groups of mice were immunized by these particles plus adjuvant formulations,then mice were tested by ELISA and neutralization assay for humoral immune response,and by lymphocyte proliferation and cytokine production assays for a cellular immune response.Results Our data demonstrated that recombinant DENV-1 VLPs consisting of prM and E protein were successfully expressed in the yeast P.pastoris.Sera of VLPs immunized mice were shown to contain a high-titer of antibodies and the neutralization assay suggested that those antibodies neutralized virus infection in vitro.Data from the T lymphocyte proliferation assay showed proliferation of T cell,and ELISA found elevated secretion levels of interferon IFN-y and IL-4.Conclusions P.pastoris-expressed DENV-1 VLPs can induce virus neutralizing antibodies and T cell responses in immunized mice.Using P.pastoris to produce VLPs offers a promising and economic strategy for dengue virus

  18. Studies on Sam68 a cell factor involved in the life cycle of foot-and-mouth disease virus

    Science.gov (United States)

    As with other RNA viruses, Foot-and-Mouth Disease Virus (FMDV) recruits various host cell factors to assist in translation and replication of the virus genome. While FMDV translation has been thoroughly investigated, much remains unknown regarding replication of the positive-sense RNA genome. In th...

  19. Acute human herpesvirus-6A infection of human mesothelial cells modulates HLA molecules.

    Science.gov (United States)

    Caselli, Elisabetta; Campioni, Diana; Cavazzini, Francesco; Gentili, Valentina; Bortolotti, Daria; Cuneo, Antonio; Di Luca, Dario; Rizzo, Roberta

    2015-09-01

    Human herpesvirus 6A (HHV-6A) causes ubiquitous infections and has been associated with several diseases in immunosuppressed and immune dysregulated individuals. Although considered a lymphotropic virus, HHV-6A has the potential to infect many cell types, inducing important alterations in the infected cell. In our search for additional potential targets for HHV-6A infection, we analyzed the susceptibility of human mesothelial cells to viral infection. HHV-6A infection was performed and analyzed on primary human mesothelial cells isolated from serous cavity fluid, infected in vitro with a cell-free HHV-6A inoculum. The results demonstrated that mesothelial cells are susceptible to in vitro HHV-6A infection, and more importantly, that the virus induces an alteration of HLA expression on the cell surface, inducing HLA class II and HLA-G de novo expression. Since mesothelial cells play a pivotal role in many processes, including inflammation and antigen presentation, we speculate that, in vivo, this virus-induced perturbation might be correlated to alterations in mesothelium functions. PMID:26085284

  20. Vaccine-induced T cell-mediated immunity plays a critical role in early protection against pseudorabies virus (suid herpes virus type 1) infection in pigs

    NARCIS (Netherlands)

    Rooij, van E.M.A.; Bruin, de M.G.M.; Visser-Hendriksen, de Y.E.; Middel, W.G.; Boersma, W.J.A.; Bianchi, A.T.J.

    2004-01-01

    The aim of our study was to evaluate the relative importance of antibody and T cell-mediated immunity in protection against pseudorabies virus (suid herpes virus type 1) infection in pigs. We induced different levels of immune responses by using: (1) a modified live vaccine; (2) the same modified li

  1. Generation of lymphomagenic mouse type-C viruses from radiation- or chemically-induced non-producer T-cell lymphoma cell lines infected with non-oncogenic ecotropic virus

    International Nuclear Information System (INIS)

    Highly lymphomagenic mouse type-C viruses were generated from radiation- or chemically-induced T-cell lymphoma cell lines of NFS/N mouse origin infected with a non-oncogenic ecotropic virus E4. By analysis of these progeny viruses, the following results were obtained. 1) The viruses were lymphomagenic in neonatally inoculated NFS/N and C3H/He mice and W/Fu rats but not in Balb/c and C57BL/6N mice, indicating that they possess the Fv-1n tropism of exogenously infected parent virus. 2) Lymphomagenic viruses consisted of plural viral subpopulations. Recombinant mink cell focus-inducing (MCF) and ecotropic viruses were cloned from them. Inoculation of either MCF or ecotropic virus alone or both viruses together did not cause lymphoma in NFS/N mice and there was no evidence of viral replication in the recipients. 3) Inoculation of either MCF- or ecotropic virus-infected NFS-ME cells alone did not cause lymphoma development in pre-irradiated NFS/N mice, while transplantation of both MCF- and ecotropic virus-infected NFS-ME cells resulted in the development of lymphomas of host origin. These results show that lymphomagenic MCF virus was generated through the recombination of E4 viral genome and a modified proviral DNA of endogenous viruses present in radiation- or chemically-induced lymphomas, and that an interaction or synergism of MCF and ecotropic viruses is required for MCF virus to exert lymphomagenic activity. (author)

  2. A thiopurine drug inhibits West Nile virus production in cell culture, but not in mice.

    Directory of Open Access Journals (Sweden)

    Pei-Yin Lim

    Full Text Available Many viruses within the Flavivirus genus cause significant disease in humans; however, effective antivirals against these viruses are not currently available. We have previously shown that a thiopurine drug, 6-methylmercaptopurine riboside (6MMPr, inhibits replication of distantly related viruses within the Flaviviridae family in cell culture, including bovine viral diarrhea virus and hepatitis C virus replicon. Here we further examined the potential antiviral effect of 6MMPr on several diverse flaviviruses. In cell culture, 6MMPr inhibited virus production of yellow fever virus, dengue virus-2 (DENV-2 and West Nile virus (WNV in a dose-dependent manner, and DENV-2 was significantly more sensitive to 6MMPr treatment than WNV. We then explored the use of 6MMPr as an antiviral against WNV in an immunocompetent mouse model. Once a day treatment of mice with 0.5 mg 6MMPr was just below the toxic dose in our mouse model, and this dose was used in subsequent studies. Mice were treated with 6MMPr immediately after subcutaneous inoculation with WNV for eight consecutive days. Treatment with 6MMPr exacerbated weight loss in WNV-inoculated mice and did not significantly affect mortality. We hypothesized that 6MMPr has low bioavailability in the central nervous system (CNS and examined the effect of pre-treatment with 6MMPr on viral loads in the periphery and CNS. Pre-treatment with 6MMPr had no significant effect on viremia or viral titers in the periphery, but resulted in significantly higher viral loads in the brain, suggesting that the effect of 6MMPr is tissue-dependent. In conclusion, despite being a potent inhibitor of flaviviruses in cell culture, 6MMPr was not effective against West Nile disease in mice; however, further studies are warranted to reduce the toxicity and/or improve the bioavailability of this potential antiviral drug.

  3. Characterization of dengue virus 2 growth in megakaryocyte-erythrocyte progenitor cells.

    Science.gov (United States)

    Clark, Kristina B; Hsiao, Hui-Mien; Bassit, Leda; Crowe, James E; Schinazi, Raymond F; Perng, Guey Chuen; Villinger, Francois

    2016-06-01

    Megakaryocyte-erythrocyte progenitor (MEP) cells are potential in vivo targets of dengue virus (DENV); the virus has been found associated with megakaryocytes ex vivo and platelets during DENV-induced thrombocytopenia. We report here that DENV serotype 2 (DENV2) propagates well in human nondifferentiated MEP cell lines (Meg01 and K562). In comparison to virus propagated in Vero cells, viruses from MEP cell lines had similar structure and buoyant density. However, differences in MEP-DENV2 stability and composition were suggested by distinct protein patterns in western blot analysis. Also, antibody neutralization of envelope domain I/II on MEP-DENV2 was reduced relative to that on Vero-DENV2. Infectious DENV2 was produced at comparable kinetics and magnitude in MEP and Vero cells. However, fewer virion structures appeared in electron micrographs of MEP cells. We propose that DENV2 infects and produces virus efficiently in megakaryocytes and that megakaryocyte impairment might contribute to dengue disease pathogenesis. PMID:27058763

  4. The Influence of Virus Infection on the Extracellular pH of the Host Cell Detected on Cell Membrane.

    Science.gov (United States)

    Liu, Hengjun; Maruyama, Hisataka; Masuda, Taisuke; Honda, Ayae; Arai, Fumihito

    2016-01-01

    Influenza virus infection can result in changes in the cellular ion levels at 2-3 h post-infection. More H(+) is produced by glycolysis, and the viral M2 proton channel also plays a role in the capture and release of H(+) during both viral entry and egress. Then the cells might regulate the intracellular pH by increasing the export of H(+) from the intracellular compartment. Increased H(+) export could lead indirectly to increased extracellular acidity. To detect changes in extracellular pH of both virus-infected and uninfected cells, pH sensors were synthesized using polystyrene beads (ϕ1 μm) containing Rhodamine B and Fluorescein isothiocyanate (FITC). The fluorescence intensity of FITC can respond to both pH and temperature. So Rhodamine B was also introduced in the sensor for temperature compensation. Then the pH can be measured after temperature compensation. The sensor was adhered to cell membrane for extracellular pH measurement. The results showed that the multiplication of influenza virus in host cell decreased extracellular pH of the host cell by 0.5-0.6 in 4 h after the virus bound to the cell membrane, compared to that in uninfected cells. Immunostaining revealed the presence of viral PB1 protein in the nucleus of virus-bound cells that exhibited extracellular pH changes, but no PB1 protein are detected in virus-unbound cells where the extracellular pH remained constant. PMID:27582727

  5. Dengue virus specific dual HLA binding T cell epitopes induce CD8+ T cell responses in seropositive individuals.

    Science.gov (United States)

    Comber, Joseph D; Karabudak, Aykan; Huang, Xiaofang; Piazza, Paolo A; Marques, Ernesto T A; Philip, Ramila

    2014-01-01

    Dengue virus infects an estimated 300 million people each year and even more are at risk of becoming infected as the virus continues to spread into new areas. Despite the increase in viral prevalence, no anti-viral medications or vaccines are approved for treating or preventing infection. CD8+ T cell responses play a major role in viral clearance. Therefore, effective vaccines that induce a broad, multi-functional T cell response with substantial cross-reactivity between all virus serotypes can have major impacts on reducing infection rates and infection related complications. Here, we took an immunoproteomic approach to identify novel MHC class I restricted T cell epitopes presented by dengue virus infected cells, representing the natural and authentic targets of the T cell response. Using this approach we identified 4 novel MHC-I restricted epitopes: 2 with the binding motif for HLA-A24 molecules and 2 with both HLA-A2 and HLA-A24 binding motifs. These peptides were able to activate CD8+ T cell responses in both healthy, seronegative individuals and in seropositive individuals who have previously been infected with dengue virus. Importantly, the dual binding epitopes activated pre-existing T cell precursors in PBMCs obtained from both HLA-A2+ and HLA-A24+ seropositive individuals. Together, the data indicate that these epitopes are immunologically relevant T cell activating peptides presented on infected cells during a natural infection and therefore may serve as candidate antigens for the development of effective multi-serotype specific dengue virus vaccines. PMID:25668665

  6. Role of CD28 co-stimulation in generation and maintenance of virus-specific T cells

    DEFF Research Database (Denmark)

    Christensen, Jeanette Erbo; Christensen, Jan P; Kristensen, Nanna N; Hansen, Nils J V; Stryhn, Anette; Thomsen, Allan R

    2002-01-01

    and virus dose play little if any role. Direct visualization of antigen-specific cells also confirms the notion that CD28 is more critical for the generation of antiviral T(h)1 cells than for T(c)1 cells generated in response to the same virus (LCMV). Most importantly, the present study reveals that...

  7. VARICELLA ZOSTER VIRUS-ITS PATHOGENESIS, LATENCY & CELL-MEDIATED IMMUNITY

    Directory of Open Access Journals (Sweden)

    Anis Ahmed

    2013-07-01

    Full Text Available Varicella zoster virus causes primary infection as chickenpox, at which time latencyis established in the neurons of the dorsal root ganglia or ganglia of the cranial nerves.Reactivation produces herpes zoster infection (HZI, commonly called shingles. Anunderstanding of the mechanisms of latency is crucial in developing effective therapies forVZV infections of the nervous system. This article describes the pathogenesis of VZVwhich includes immune response to the virus, immune evasion by the virus, mechanism ofits latency and cell-mediated immunity.

  8. Reverse Genetics Demonstrates that Proteolytic Processing of the Ebola Virus Glycoprotein Is Not Essential for Replication in Cell Culture

    OpenAIRE

    Neumann, Gabriele; Feldmann, Heinz; Watanabe, Shinji; Lukashevich, Igor; Kawaoka, Yoshihiro

    2002-01-01

    Ebola virus, a prime example of an emerging pathogen, causes fatal hemorrhagic fever in humans and in nonhuman primates. Identification of major determinants of Ebola virus pathogenicity has been hampered by the lack of effective strategies for experimental mutagenesis. Here we exploit a reverse genetics system that allows the generation of Ebola virus from cloned cDNA to engineer a mutant Ebola virus with an altered furin recognition motif in the glycoprotein (GP). When expressed in cells, t...

  9. Alpha 4 integrin directs virus-activated CD8+ T cells to sites of infection

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Andersson, E C; Scheynius, A; Marker, O; Thomsen, Allan Randrup

    1995-01-01

    response is induced, which is associated with marked CD8+ cell-mediated inflammation. Two expressions of LCMV-induced inflammation were studied: meningitis induced by intracerebral infection and adoptive transfer of virus-specific delayed-type hypersensitivity. Our previous studies have shown that LCMV...... infection results in the appearance of activated CD8+ cells with an increased expression of VLA-4. In this study we have compared various T cell high and low responder situations, and these experiments revealed that acute inflammation correlates directly with VLA-4 expression on splenic CD8+ cells. This...... ability to transfer virus-specific, delayed-type hypersensitivity when the donor cells were given i.v., but not when the cells were injected directly into the test site. Co-transfer of CD8-depleted cells with anti-VLA-4-blocked cells did not reveal any cooperation. Taken together, these results indicate...

  10. Host range restriction of vaccinia virus in Chinese hamster ovary cells: relationship to shutoff of protein synthesis

    International Nuclear Information System (INIS)

    Chinese hamster ovary cells were found to be nonpermissive for vaccinia virus. Although early virus-induced events occurred in these cells (RNA and polypeptide synthesis), subsequent events appeared to be prevented by a very rapid and nonselective shutoff of protein synthesis. Within less than 2 h after infection, both host and viral protein syntheses were arrested. At low multiplicities of infection, inhibition of RNA synthesis with cordycepin resulted in failure of the virus to block protein synthesis. Moreover, infection of the cells in the presence of cycloheximide prevented the immediate onset of shutoff after reversal of cycloheximide. Inactivation of virus particles by uv irradiation also impaired the capacity of the virus to inhibit protein synthesis. These results suggested that an early vaccinia virus-coded product was implicated in the shutoff of protein synthesis. Either the nonpermissive Chinese hamster ovary cells were more sensitive to this inhibition than permissive cells, or a regulatory control of the vaccinia shutoff function was defective

  11. Protein stabilization explains the gag requirement for transformation of lymphoid cells by Abelson murine leukemia virus

    OpenAIRE

    Prywes, R; Hoag, J; Rosenberg, N; Baltimore, D

    1985-01-01

    The single protein encoded by Abelson murine leukemia virus is a fusion of sequence from the retroviral gag genes with the v-abl sequence. Deletion of most of the gag region from the transforming protein results in a virus capable of transforming fibroblasts but no longer capable of transforming lymphoid cells. Smaller deletions in gag reveal that p15 gag sequences are responsible for this effect, whereas deletion of p12 sequences had no effect on lymphoid transformation. In transformed fibro...

  12. Array Analysis of Simian Varicella Virus Gene Transcription in Productively Infected Cells in Tissue Culture

    OpenAIRE

    Deitch, Steven B.; Gilden, Donald H.; Wellish, Mary; Smith, John; Cohrs, Randall J.; Mahalingam, Ravi

    2005-01-01

    Simian varicella virus (SVV) is a neurotropic alphaherpesvirus of monkeys that is a model for varicella pathogenesis and latency. Like human varicella-zoster virus (VZV), SVV causes chicken pox (varicella), becomes latent in ganglia along the entire neuraxis, and reactivates to produce shingles (zoster). We developed macroarrays to determine the extent of viral transcription from all 70 predicted SVV open reading frames (ORFs) in infected cells in tissue culture. Cloned fragments (200 to 400 ...

  13. Human immunodeficiency virus infection of T cells and monocytes proceeds via receptor-mediated endocytosis

    OpenAIRE

    1988-01-01

    The rates of internalization and uncoating of 32P-labelled human immunodeficiency virus (HIV) in the human T lymphoid cell line CEM are consonant with a receptor-mediated endocytosis mechanism of entry. This interpretation was affirmed by electron microscopic observation of virions within endosomes. Virus binding and infectivity were inhibited to the same extent by pretreatment with OKT4A antibody, therefore, the CD4 receptor-dependent pathway of internalization appears to be the infectious r...

  14. Human T cell responses to dengue virus antigens. Proliferative responses and interferon gamma production.

    OpenAIRE

    Kurane, I; Innis, B L; Nisalak, A; Hoke, C; Nimmannitya, S; Meager, A.; Ennis, F A

    1989-01-01

    The severe complications of dengue virus infections, hemorrhagic manifestations and shock, are more commonly observed during secondary dengue virus infections than during primary infections. It has been speculated that these complications are mediated by cross-reactive host-immune responses. We have begun to analyze human T cell responses to dengue antigens in vitro to explain the possible role of T lymphocytes in the pathogenesis of these complications. Dengue antigens induce proliferative r...

  15. Immunofluorescence of bovine virus diarrhea viral antigen in white blood cells from experimentally infected immunocompetent calves.

    OpenAIRE

    Bezek, D M; Baker, J. C.; Kaneene, J B

    1988-01-01

    A study to evaluate the detection of bovine virus diarrhea viral antigen using immunofluorescence testing of white blood cells was conducted. Five colostrum-deprived calves were inoculated intravenously with a cytopathic strain of the virus. Lymphocyte and buffy coat smears were prepared daily for direct immunofluorescent staining for detection of antigen. Lymphocytes were separated from heparinized blood using a Ficoll density procedure. Buffy coat smears were prepared from centrifuged blood...

  16. Varicella-zoster virus glycoprotein expression differentially induces the unfolded protein response in infected cells

    OpenAIRE

    Carpenter, John E.; Grose, Charles

    2014-01-01

    Varicella-zoster virus (VZV) is a human herpesvirus that spreads to children as varicella or chicken pox. The virus then establishes latency in the nervous system and re-emerges, typically decades later, as zoster or shingles. We have reported previously that VZV induces autophagy in infected cells as well as exhibiting evidence of the Unfolded Protein Response (UPR): XBP1 splicing, a greatly expanded Endoplasmic Reticulum (ER) and CHOP expression. Herein we report the results of a UPR specif...

  17. Varicella-Zoster Virus glycoprotein expression differentially induces the unfolded protein response in infected cells.

    OpenAIRE

    John Earl Carpenter; Charles eGrose

    2014-01-01

    Varicella-zoster virus (VZV) is a human herpesvirus that spreads to children as varicella or chicken pox. The virus then establishes latency in the nervous system and re-emerges, typically decades later, as zoster or shingles. We have reported previously that VZV induces autophagy in infected cells as well as exhibiting evidence of the Unfolded Protein Response (UPR): XBP1 splicing, a greatly expanded Endoplasmic Reticulum (ER) and CHOP expression. Herein we report the results of a UPR specif...

  18. Suspected chromosomally integrated human herpes virus 6 in hematopoietic stem cell transplantation

    OpenAIRE

    Anna Todisco; Maria Landi; Beatrice Paola Festa; Lidia Santoro; Gabriella Storti; Giulia Campanini; Raffaele Ariola; Franca Romeo; Generoso Violano

    2016-01-01

    Background and aims: We report a case of a 27-year-old male affected by acute myeloid leukaemia MLL-PTD positive. After autologous stem cell transplantation, he was monitored based on cytomegalovirus, Epstein-Barr virus and human herpes virus 6 (HHV-6) DNA quantification in blood. Relapse occurred one year after transplantation; then the patient underwent to allogenic bone marrow transplantation using genotypically HLA-identical donor (sister). HHV-6 DNAemia was positive and persistently elev...

  19. A Case of Pneumonia Caused by Pneumocystis Jirovecii and Cryptococcus Neoformans in a Patient with HTLV-1 Associated Adult T- Cell Leukemia/Lymphoma: Occam's Razor Blunted.

    Science.gov (United States)

    Desai, Anish; Fe, Alexander; Desai, Amishi; Ilowite, Jonathan; Cunha, Burke A; Mathew, Joseph P

    2016-02-01

    Adult T-cell leukemia/lymphoma (ATLL) is usually preceded by infection with human T-cell lymphotropic virus I (HTLV-I). Patients with ATLL frequently get opportunistic infections of the lungs, intestines, and central nervous system. Pneumocystis pneumonia is commonly known as an AIDS defining illness. Grocott's methenamine silver stain of bronchoalveolar lavage (BAL) samples obtained via bronchoscopy remain the gold standard for diagnosis. Pulmonary cryptococcosis is seen in patients with T-cell deficiencies and a diagnosis is made by culture of sputum, BAL, or occasionally of pleural fluid. We present the second case of coinfection with these two organisms in a patient with ATLL who was successfully treated with trimethoprim-sulfamethoxazole, corticosteroids, and fluconazole. We illustrate the need for high clinical vigilance for seeking out an additional diagnosis, especially in immunocompromised patients if they are not improving despite receiving appropriate treatment. PMID:27024978

  20. Novel avian influenza A (H7N9 virus induces impaired interferon responses in human dendritic cells.

    Directory of Open Access Journals (Sweden)

    Veera Arilahti

    Full Text Available In March 2013 a new avian influenza A(H7N9 virus emerged in China and infected humans with a case fatality rate of over 30%. Like the highly pathogenic H5N1 virus, H7N9 virus is causing severe respiratory distress syndrome in most patients. Based on genetic analysis this avian influenza A virus shows to some extent adaptation to mammalian host. In the present study, we analyzed the activation of innate immune responses by this novel H7N9 influenza A virus and compared these responses to those induced by the avian H5N1 and seasonal H3N2 viruses in human monocyte-derived dendritic cells (moDCs. We observed that in H7N9 virus-infected cells, interferon (IFN responses were weak although the virus replicated as well as the H5N1 and H3N2 viruses in moDCs. H7N9 virus-induced expression of pro-inflammatory cytokines remained at a significantly lower level as compared to H5N1 virus-induced "cytokine storm" seen in human moDCs. However, the H7N9 virus was extremely sensitive to the antiviral effects of IFN-α and IFN-β in pretreated cells. Our data indicates that different highly pathogenic avian viruses may show considerable differences in their ability to induce host antiviral responses in human primary cell models such as moDCs. The unexpected appearance of the novel H7N9 virus clearly emphasizes the importance of the global influenza surveillance system. It is, however, equally important to systematically characterize in normal human cells the replication capacity of the new viruses and their ability to induce and respond to natural antiviral substances such as IFNs.

  1. Role of CD4+ and CD8+ T cells in murine resistance to street rabies virus.

    OpenAIRE

    Perry, L. L.; Lodmell, D L

    1991-01-01

    Mice of the SJL/J and BALB/cByJ inbred strains are naturally resistant to street rabies virus (SRV) injected via the intraperitoneal route. To determine the cellular mechanism of resistance, monoclonal antibodies specific for CD4+ or CD8+ subsets of T cells were used to deplete the respective cell population in SRV-infected animals. Elimination of CD4+ T-helper cells abrogated the production of immunoglobulin G (IgG) neutralizing antibodies in response to rabies virus infection and reversed t...

  2. Tubule-guided cell-to-cell movement of a plant virus requires class XI myosin motors.

    Directory of Open Access Journals (Sweden)

    Khalid Amari

    2011-10-01

    Full Text Available Cell-to-cell movement of plant viruses occurs via plasmodesmata (PD, organelles that evolved to facilitate intercellular communications. Viral movement proteins (MP modify PD to allow passage of the virus particles or nucleoproteins. This passage occurs via several distinct mechanisms one of which is MP-dependent formation of the tubules that traverse PD and provide a conduit for virion translocation. The MP of tubule-forming viruses including Grapevine fanleaf virus (GFLV recruit the plant PD receptors called Plasmodesmata Located Proteins (PDLP to mediate tubule assembly and virus movement. Here we show that PDLP1 is transported to PD through a specific route within the secretory pathway in a myosin-dependent manner. This transport relies primarily on the class XI myosins XI-K and XI-2. Inactivation of these myosins using dominant negative inhibition results in mislocalization of PDLP and MP and suppression of GFLV movement. We also found that the proper targeting of specific markers of the Golgi apparatus, the plasma membrane, PD, lipid raft subdomains within the plasma membrane, and the tonoplast was not affected by myosin XI-K inhibition. However, the normal tonoplast dynamics required myosin XI-K activity. These results reveal a new pathway of the myosin-dependent protein trafficking to PD that is hijacked by GFLV to promote tubule-guided transport of this virus between plant cells.

  3. Early Events in Chikungunya Virus Infection-From Virus Cell Binding to Membrane Fusion

    NARCIS (Netherlands)

    van Duijl-Richter, Mareike K. S.; Hoornweg, Tabitha E.; Rodenhuis-Zybert, Izabela A.; Smit, Jolanda M.

    2015-01-01

    Chikungunya virus (CHIKV) is a rapidly emerging mosquito-borne alphavirus causing millions of infections in the tropical and subtropical regions of the world. CHIKV infection often leads to an acute self-limited febrile illness with debilitating myalgia and arthralgia. A potential long-term complica

  4. Nectin4 Is an Epithelial Cell Receptor for Canine Distemper Virus and Involved in Neurovirulence

    OpenAIRE

    Pratakpiriya, Watanyoo; Seki, Fumio; Otsuki, Noriyuki; Sakai, Kouji; FUKUHARA, HIDEO; Katamoto, Hiromu; HIRAI, Takuya; Maenaka, Katsumi; Techangamsuwan, Somporn; LAN, Nguyen Thi; Takeda, Makoto; Yamaguchi, Ryoji

    2012-01-01

    Canine distemper virus (CDV) uses signaling lymphocyte activation molecule (SLAM), expressed on immune cells, as a receptor. However, epithelial and neural cells are also affected by CDV in vivo. Wild-type CDV strains showed efficient replication with syncytia in Vero cells expressing dog nectin4, and the infection was blocked by an anti-nectin4 antibody. In dogs with distemper, CDV antigen was preferentially detected in nectin4-positive neurons and epithelial cells, suggesting that nectin4 i...

  5. Dendritic cells as Achilles' heel and Trojan horse during varicella zoster virus infection

    OpenAIRE

    Günther eSchönrich; Raftery, Martin J.

    2015-01-01

    Varicella zoster virus (VZV), a human alphaherpesvirus, causes varicella and subsequently estab-lishes latency within sensory nerve ganglia. Later in life VZV can reactivate to cause herpes zoster. A reduced frequency of VZV-specific T cells is strongly associated with herpes zoster illustrating that these immune cells are central to control latency. Dendritic cells (DCs) are required for the generation of VZV-specific T cells. However, DCs can also be infected in vitro and in vivo allowing V...

  6. Dendritic cells as Achilles’ heel and Trojan horse during varicella zoster virus infection

    OpenAIRE

    Schönrich, Günther; Raftery, Martin J.

    2015-01-01

    Varicella zoster virus (VZV), a human alphaherpesvirus, causes varicella and subsequently establishes latency within sensory nerve ganglia. Later in life VZV can reactivate to cause herpes zoster. A reduced frequency of VZV-specific T cells is strongly associated with herpes zoster illustrating that these immune cells are central to control latency. Dendritic cells (DCs) are required for the generation of VZV-specific T cells. However, DCs can also be infected in vitro and in vivo allowing VZ...

  7. Ebola virus-like particles produced in insect cells exhibit dendritic cell stimulating activity and induce neutralizing antibodies

    International Nuclear Information System (INIS)

    Recombinant baculoviruses (rBV) expressing Ebola virus VP40 (rBV-VP40) or GP (rBV-GP) proteins were generated. Infection of Sf9 insect cells by rBV-VP40 led to assembly and budding of filamentous particles from the cell surface as shown by electron microscopy. Ebola virus-like particles (VLPs) were produced by coinfection of Sf9 cells with rBV-VP40 and rBV-GP, and incorporation of Ebola GP into VLPs was demonstrated by SDS-PAGE and Western blot analysis. Recombinant baculovirus infection of insect cells yielded high levels of VLPs, which were shown to stimulate cytokine secretion from human dendritic cells similar to VLPs produced in mammalian cells. The immunogenicity of Ebola VLPs produced in insect cells was evaluated by immunization of mice. Analysis of antibody responses showed that most of the GP-specific antibodies were of the IgG2a subtype, while no significant level of IgG1 subtype antibodies specific for GP was induced, indicating the induction of a Th1-biased immune response. Furthermore, sera from Ebola VLP immunized mice were able to block infection by Ebola GP pseudotyped HIV virus in a single round infection assay, indicating that a neutralizing antibody against the Ebola GP protein was induced. These results show that production of Ebola VLPs in insect cells using recombinant baculoviruses represents a promising approach for vaccine development against Ebola virus infection

  8. A20 Deficiency in Lung Epithelial Cells Protects against Influenza A Virus Infection

    Science.gov (United States)

    Vereecke, Lars; Mc Guire, Conor; Sze, Mozes; Schuijs, Martijn J.; Willart, Monique; Itati Ibañez, Lorena; Hammad, Hamida; Lambrecht, Bart N.; Beyaert, Rudi; Saelens, Xavier; van Loo, Geert

    2016-01-01

    A20 negatively regulates multiple inflammatory signalling pathways. We here addressed the role of A20 in club cells (also known as Clara cells) of the bronchial epithelium in their response to influenza A virus infection. Club cells provide a niche for influenza virus replication, but little is known about the functions of these cells in antiviral immunity. Using airway epithelial cell-specific A20 knockout (A20AEC-KO) mice, we show that A20 in club cells critically controls innate immune responses upon TNF or double stranded RNA stimulation. Surprisingly, A20AEC-KO mice are better protected against influenza A virus challenge than their wild type littermates. This phenotype is not due to decreased viral replication. Instead host innate and adaptive immune responses and lung damage are reduced in A20AEC-KO mice. These attenuated responses correlate with a dampened cytotoxic T cell (CTL) response at later stages during infection, indicating that A20AEC-KO mice are better equipped to tolerate Influenza A virus infection. Expression of the chemokine CCL2 (also named MCP-1) is particularly suppressed in the lungs of A20AEC-KO mice during later stages of infection. When A20AEC-KO mice were treated with recombinant CCL2 the protective effect was abrogated demonstrating the crucial contribution of this chemokine to the protection of A20AEC-KO mice to Influenza A virus infection. Taken together, we propose a mechanism of action by which A20 expression in club cells controls inflammation and antiviral CTL responses in response to influenza virus infection. PMID:26815999

  9. Reactivation of UV and γ-inactivated herpes virus in BHK cells

    International Nuclear Information System (INIS)

    The DNA-repair capabilities of baby hamster kidney (BHK) cells were investigated by comparing the reactivation of irradiated herpes simplex virus type I (HSV1) in BHK cells with its reactivation in mouse fibroblasts and in normal and repair-deficient human diploid fibroblasts. BHK cells were found to have an intermediate ability to reactivate UV-irradiated HSV1 (the viral D0 was 14 J/m2) relative to normal human fibroblasts (viral D0 = 19 J/m2) and xeroderma pigmentosum (XP) group A cells (viral D0 = 4.5 J/m2). With mouse L 929 cells as the host, the response of the UV-irradiated virus was biphasic with D0s of 4.6 and 30 J/m2 for the low- and high-dose components respectively. In contrast to the response following UV radiation, γ-irradiated HSV1 was similarly reactivated by BHK and normal human cells (the D0s for the irradiated virus in BHK and CRL 1106 were 55 and 51 krad, respectively, whereas xeroderma pigmentosum cells were slightly less efficient in the repair of γ-irradiated virus (D0 = 45 krad)). UV irradiation of BHK host cells 0-48 h prior to infection enhanced the reactivation of UV-irradiated HSV. (orig.)

  10. CELL CULTURE STUDIES WITH THE IMC-HZ-1 NONOCCLUDED VIRUS

    Science.gov (United States)

    Studies were conducted on an adventitious agent (Hz-lv) isolated from the IMC-Hz-1 cell line. It appeared identical to the virus first obtained by Granados et al. from a persistent infection of this cell line. Restriction endonuclease digestion of Hz-lv DNA indicated the agent wa...

  11. Normal T-cell telomerase activity and upregulation in human immunodeficiency virus-1 infection

    NARCIS (Netherlands)

    Wolthers, KC; Otto, SA; Wisman, GBA; Fleury, S; Reiss, P; ten Kate, RW; van der Zee, AGJ; Miedema, F

    1999-01-01

    In human immunodeficiency virus (HIV)-1 infection, decrease of telomere length is mainly found in CD8(+) T cells and not in CD4(+) T cells. Telomerase, a ribonucleoprotein enzyme that can synthesize telomeric sequence onto chromosomal ends, can compensate for telomere loss. Here, we investigated if

  12. Measles virus-specific murine T cell clones: characterization of fine specificity function.

    NARCIS (Netherlands)

    P. de Vries (Petra); J.P.M. Versteeg-van Oosten (José); I.K.G. Visser (Ilona); R.S. van Binnendijk (Rob); S.A. Langeveld (Sacha); A.D.M.E. Osterhaus (Ab); F.G.C.M. Uytdehaag (Fons)

    1989-01-01

    textabstractMeasles virus (MV)-specific murine helper T cell clones (Thy-1.2+, CD4+, CD8-) were generated from mice immunized with MV-infected mouse brain homogenate by limiting dilution and in vitro stimulation of spleen cells with UV-inactivated MV Ag. The protein specificity of 7 out of 37 stable

  13. Concanavalin A-induced activation of lymphocytic choriomeningitis virus memory lymphocytes into specifically cytotoxic T cells

    DEFF Research Database (Denmark)

    Marker, O; Thomsen, Allan Randrup; Andersen, G T

    1977-01-01

    When spleen cells, which have been primed to Lymphocytic Choriomeningitis (LCM) virus during a primary infection several months previously, are stimulated in vitro with Con A. highly specific secondary cytotoxic effector cells are generated. The degree of cytotoxicity revealed by such Con A...

  14. Small non-coding RNAs, mammalian cells, and viruses: regulatory interactions?

    Directory of Open Access Journals (Sweden)

    Benkirane Monsef

    2007-10-01

    Full Text Available Abstract Recent findings suggest that mammalian cells can use small non-coding RNAs (ncRNA to regulate physiological viral infections. Here, we comment on several lines of evidence that support this concept. We discuss how viruses may in turn protect, suppress, evade, modulate, or adapt to the host cell's ncRNA regulatory schema.

  15. Inter-laboratory comparison of cell lines for susceptibility to three viruses: VHSV, IHNV and IPNV

    DEFF Research Database (Denmark)

    Lorenzen, Ellen; Carstensen, Bendix; Olesen, Niels Jørgen

    1999-01-01

    pancreatic necrosis Virus (IPNV), and the cell lines derived from bluegill fry (BF-2), chinook salmon embryo (CHSE-214), epithelioma papulosum cyprini (EPC), fathead minnow (FHM) and rainbow trout gonad (RTG-2). The results showed that for isolation of VHSV, BF-2 and RTG-2 cells performed equally well and...

  16. High-throughput quantitative proteomic analysis of dengue virus type 2 infected A549 cells.

    Directory of Open Access Journals (Sweden)

    Han-Chen Chiu

    Full Text Available Disease caused by dengue virus is a global health concern with up to 390 million individuals infected annually worldwide. There are no vaccines or antiviral compounds available to either prevent or treat dengue disease which may be fatal. To increase our understanding of the interaction of dengue virus with the host cell, we analyzed changes in the proteome of human A549 cells in response to dengue virus type 2 infection using stable isotope labelling in cell culture (SILAC in combination with high-throughput mass spectrometry (MS. Mock and infected A549 cells were fractionated into nuclear and cytoplasmic extracts before analysis to identify proteins that redistribute between cellular compartments during infection and reduce the complexity of the analysis. We identified and quantified 3098 and 2115 proteins in the cytoplasmic and nuclear fractions respectively. Proteins that showed a significant alteration in amount during infection were examined using gene enrichment, pathway and network analysis tools. The analyses revealed that dengue virus infection modulated the amounts of proteins involved in the interferon and unfolded protein responses, lipid metabolism and the cell cycle. The SILAC-MS results were validated for a select number of proteins over a time course of infection by Western blotting and immunofluorescence microscopy. Our study demonstrates for the first time the power of SILAC-MS for identifying and quantifying novel changes in cellular protein amounts in response to dengue virus infection.

  17. Use of a commercial enzyme immunoassay to monitor dengue virus replication in cultured cells

    Directory of Open Access Journals (Sweden)

    del Angel Rosa M

    2008-04-01

    Full Text Available Abstract Current methods for dengue virus quantitation are either time consuming, technically demanding or costly. As an alternative, the commercial enzyme immunoassay Platelia™ Dengue NS1 AG (Bio-Rad Laboratories was used to monitor semiquantitatively dengue virus replication in cultured cells. The presence of NS1 protein was evaluated in supernatants from Vero and C6/36 HT cells infected with dengue virus. The amount of NS1 detected in the supernatants of infected cells was proportional to the initial MOI used and to the time of post infection harvest. This immunoassay was also able to detect the presence of NS1 in the supernatants of infected human macrophages. Inhibition of dengue virus replication in C6/36 HT cells treated with lysosomotropic drugs was readily monitored with the use of this assay. These results suggest that the Platelia™ Dengue NS1 AG kit can be used as a fast and reliable surrogate method for the relative quantitation of dengue virus replication in cultured cells.

  18. TCR Down-Regulation Controls Virus-Specific CD8+ T Cell Responses

    DEFF Research Database (Denmark)

    Bonefeld, Charlotte Menné; Haks, Mariëlle; Nielsen, Bodil;

    2008-01-01

    The CD3gamma di-leucine-based motif plays a central role in TCR down-regulation. However, little is understood about the role of the CD3gamma di-leucine-based motif in physiological T cell responses. In this study, we show that the expansion in numbers of virus-specific CD8(+) T cells is impaired...... in mice with a mutated CD3gamma di-leucine-based motif. The CD3gamma mutation did not impair early TCR signaling, nor did it compromise recruitment or proliferation of virus-specific T cells, but it increased the apoptosis rate of the activated T cells by increasing down-regulation of the...... antiapoptotic molecule Bcl-2. This resulted in a 2-fold reduction in the clonal expansion of virus-specific CD8(+) T cells during the acute phase of vesicular stomatitis virus and lymphocytic choriomeningitis virus infections. These results identify an important role of CD3gamma-mediated TCR down-regulation in...

  19. TCR down-regulation controls virus-specific CD8+ T cell responses

    DEFF Research Database (Denmark)

    Bonefeld, Charlotte Menné; Haks, Mariëlle; Nielsen, Bodil;

    2008-01-01

    The CD3gamma di-leucine-based motif plays a central role in TCR down-regulation. However, little is understood about the role of the CD3gamma di-leucine-based motif in physiological T cell responses. In this study, we show that the expansion in numbers of virus-specific CD8(+) T cells is impaired...... in mice with a mutated CD3gamma di-leucine-based motif. The CD3gamma mutation did not impair early TCR signaling, nor did it compromise recruitment or proliferation of virus-specific T cells, but it increased the apoptosis rate of the activated T cells by increasing down-regulation of the...... antiapoptotic molecule Bcl-2. This resulted in a 2-fold reduction in the clonal expansion of virus-specific CD8(+) T cells during the acute phase of vesicular stomatitis virus and lymphocytic choriomeningitis virus infections. These results identify an important role of CD3gamma-mediated TCR down-regulation in...

  20. The role of T-cell-mediated mechanisms in virus infections of the nervous system.

    Science.gov (United States)

    Dörries, R

    2001-01-01

    T lymphocytes play a decisive role in the course and clinical outcome of viral CNS infection. Summarizing the information presented in this review, the following sequence of events might occur during acute virus infection: After invasion of the host and a few initial rounds of replication, the virus reaches the CNS in most cases by hematogeneous spread. After passage through the BBB, CNS cells are infected and replication of virus in brain cells causes activation of the surrounding microglia population. Moreover, local production of IFN-alpha/beta induces expression of MHC antigens on CNS cells, and microglial cells start to phagocytose cellular debris, which accumulates as a result of virus-induced cytopathogenic effects. Upon phagocytosis, microglia becomes more activated; they up-regulate MHC molecules, acquire antigen presentation capabilities and secrete chemokines. This will initiate up-regulation of adhesion molecules on adjacent endothelial cells of the BBB. Transmigration of activated T lymphocytes through the BBB is followed by interaction with APC, presenting the appropriate peptides in the context of MHC antigens. It appears that CD8+ T lymphocytes are amongst the first mononuclear cells to arrive at the infected tissue. Without a doubt, their induction and attraction is deeply influenced by natural killer cells, which, after virus infection, secrete IFN-gamma, a cytokine that stimulates CD8+ T cells and diverts the immune response to a TH1-type CD4+ T cell-dominated response. Following the CD8+ T lymphocytes, tissue-penetrating, TH1 CD4+ T cells contact local APC. This results in a tremendous up-regulation of MHC molecules and secretion of more chemotactic and toxic substances. Consequently an increasing number of inflammatory cells, including macrophages/microglia and finally antibody-secreting plasma cells, are attracted to the site of virus infection. All trapped cells are mainly terminally differentiated cells that are going to enter apoptosis

  1. Apoptosis and pro-inflammatory cytokine response of mast cells induced by influenza A viruses.

    Directory of Open Access Journals (Sweden)

    Bo Liu

    Full Text Available The pathogenesis of the influenza A virus has been investigated heavily, and both the inflammatory response and apoptosis have been found to have a definitive role in this process. The results of studies performed by the present and other groups have indicated that mast cells may play a role in the severity of the disease. To further investigate cellular responses to influenza A virus infection, apoptosis and inflammatory response were studied in mouse mastocytoma cell line P815. This is the first study to demonstrate that H1N1 (A/WSN/33, H5N1 (A/Chicken/Henan/1/04, and H7N2 (A/Chicken/Hebei/2/02 influenza viruses can induce mast cell apoptosis. They were found to do this mainly through the mitochondria/cytochrome c-mediated intrinsic pathway, and the activation of caspase 8-mediated extrinsic pathway was here found to be weak. Two pro-apoptotic Bcl-2 homology domain 3 (BH3 -only molecules Bim and Puma appeared to be involved in the apoptotic pathways. When virus-induced apoptosis was inhibited in P815 cells using pan-caspase (Z-VAD-fmk and caspase-9 (Z-LEHD-fmk inhibitors, the replication of these three subtypes of viruses was suppressed and the secretions of pro-inflammatory cytokines and chemokines, including IL-6, IL-18, TNF-α, and MCP-1, decreased. The results of this study may further understanding of the role of mast cells in host defense and pathogenesis of influenza virus. They may also facilitate the development of novel therapeutic aids against influenza virus infection.

  2. Expression Analysis Highlights AXL as a Candidate Zika Virus Entry Receptor in Neural Stem Cells.

    Science.gov (United States)

    Nowakowski, Tomasz J; Pollen, Alex A; Di Lullo, Elizabeth; Sandoval-Espinosa, Carmen; Bershteyn, Marina; Kriegstein, Arnold R

    2016-05-01

    The recent outbreak of Zika virus (ZIKV) in Brazil has been linked to substantial increases in fetal abnormalities and microcephaly. However, information about the underlying molecular and cellular mechanisms connecting viral infection to these defects remains limited. In this study we have examined the expression of receptors implicated in cell entry of several enveloped viruses including ZIKV across diverse cell types in the developing brain. Using single-cell RNA-seq and immunohistochemistry, we found that the candidate viral entry receptor AXL is highly expressed by human radial glial cells, astrocytes, endothelial cells, and microglia in developing human cortex and by progenitor cells in developing retina. We also show that AXL expression in radial glia is conserved in developing mouse and ferret cortex and in human stem cell-derived cerebral organoids, highlighting multiple experimental systems that could be applied to study mechanisms of ZIKV infectivity and effects on brain development. PMID:27038591

  3. Dendritic Cell Internalization of Foot-and-Mouth Disease Virus: Influence of Heparan Sulfate Binding on Virus Uptake and Induction of the Immune Response▿

    OpenAIRE

    Harwood, Lisa J.; Gerber, Heidi; Sobrino, Francisco; Summerfield, Artur; McCullough, Kenneth C.

    2008-01-01

    Dendritic cells (DC), which are essential for inducing and regulating immune defenses and responses, represent the critical target for vaccines against pathogens such as foot-and-mouth disease virus (FMDV). Although it is clear that FMDV enters epithelial cells via integrins, little is known about FMDV interaction with DC. Accordingly, DC internalization of FMDV antigen was analyzed by comparing vaccine virus dominated by heparan sulfate (HS)-binding variants with FMDV lacking HS-binding capa...

  4. Simultaneous Cell-to-Cell Transmission of Human Immunodeficiency Virus to Multiple Targets through Polysynapses▿ †

    Science.gov (United States)

    Rudnicka, Dominika; Feldmann, Jérôme; Porrot, Françoise; Wietgrefe, Steve; Guadagnini, Stéphanie; Prévost, Marie-Christine; Estaquier, Jérôme; Haase, Ashley T.; Sol-Foulon, Nathalie; Schwartz, Olivier

    2009-01-01

    Human immunodeficiency virus type 1 (HIV-1) efficiently propagates through cell-to-cell contacts, which include virological synapses (VS), filopodia, and nanotubes. Here, we quantified and characterized further these diverse modes of contact in lymphocytes. We report that viral transmission mainly occurs across VS and through “polysynapses,” a rosette-like structure formed between one infected cell and multiple adjacent recipients. Polysynapses are characterized by simultaneous HIV clustering and transfer at multiple membrane regions. HIV Gag proteins often adopt a ring-like supramolecular organization at sites of intercellular contacts and colocalize with CD63 tetraspanin and raft components GM1, Thy-1, and CD59. In donor cells engaged in polysynapses, there is no preferential accumulation of Gag proteins at contact sites facing the microtubule organizing center. The LFA-1 adhesion molecule, known to facilitate viral replication, enhances formation of polysynapses. Altogether, our results reveal an underestimated mode of viral transfer through polysynapses. In HIV-infected individuals, these structures, by promoting concomitant infection of multiple targets in the vicinity of infected cells, may facilitate exponential viral growth and escape from immune responses. PMID:19369333

  5. Modulation of gene expression in a human cell line caused by poliovirus, vaccinia virus and interferon

    Directory of Open Access Journals (Sweden)

    Hoddevik Gunnar

    2007-03-01

    Full Text Available Abstract Background The project was initiated to describe the response of a human embryonic fibroblast cell line to the replication of two different viruses, and, more specifically, to look for candidate genes involved in viral defense. For this purpose, the cells were synchronously infected with poliovirus in the absence or presence of interferon-alpha, or with vaccinia virus, a virus that is not inhibited by interferon. By comparing the changes in transcriptosome due to these different challenges, it should be possible to suggest genes that might be involved in defense. Results The viral titers were sufficient to yield productive infection in a majority of the cells. The cells were harvested in triplicate at various time-points, and the transcriptosome compared with mock infected cells using oligo-based, global 35 k microarrays. While there was very limited similarities in the response to the different viruses, a large proportion of the genes up-regulated by interferon-alpha were also up-regulated by poliovirus. Interferon-alpha inhibited poliovirus replication, but there were no signs of any interferons being induced by poliovirus. The observations suggest that the cells do launch an antiviral response to poliovirus in the absence of interferon. Analyses of the data led to a list of candidate antiviral genes. Functional information was limited, or absent, for most of the candidate genes. Conclusion The data are relevant for our understanding of how the cells respond to poliovirus and vaccinia virus infection. More annotations, and more microarray studies with related viruses, are required in order to narrow the list of putative defence-related genes.

  6. Suppression of local RNA silencing is not sufficient to promote cell-to-cell movement of Turnip crinkle virus in Nicotiana benthamiana

    OpenAIRE

    Shi, Yan; Ryabov, Eugene V.; van Wezel, Rene; Li, Chunyang; Jin, Mingfei; Wang, Wenjing; Fan, Zaifeng; Hong, Yiguo

    2009-01-01

    The biological relationship between suppression of RNA silencing and virus movement poses an intriguing question in virus-plant interactions. Here, we have used a local RNA silencing assay, based on a movement-deficient Turnip crinkle virus TCV/GFPΔCP, to investigate the influence of silencing suppression by three different viral suppressors: the TCV 38K coat protein (CP), the 126K protein of Tobacco mosaic virus (TMV), and P19 of Tomato bushy stunt virus (TBSV) on cell-to-cell movement and l...

  7. Successful propagation of Alkhumra (misnamed as Alkhurma) virus in C6/36 mosquito cells.

    Science.gov (United States)

    Madani, Tariq A; Kao, Moujahed; Azhar, Esam I; Abuelzein, El-Tayeb M E; Al-Bar, Hussein M S; Abu-Araki, Huda; Ksiazek, Thomas G

    2012-03-01

    Epidemiological data suggest that Alkhumra (misnamed as Alkhurma) virus (ALKV) is transmitted from livestock animals to humans by direct contact with animals or by the mosquito bites, but not by ticks. To assess the ability of the virus to replicate in mosquito cells, serum and plasma of seven acutely febrile patients with clinically suspected ALKV infection reported in Najran, Saudi Arabia in 2009 were inoculated onto Aedes albopictus mosquito cells (C6/36) and directly examined with ALKV-RNA-specific real time RT-PCR as well as indirect immunfluorescence assay (IFA) using ALKV-specific polyclonal antibodies. The isolated virus was titrated in the mammalian rhesus monkey kidney cells (LLC-MK2). Five of the seven specimens were RT-PCR- and culture-positive demonstrating cytopathic effects in the form of cell rounding and aggregation appearing on day 3 post inoculation with syncytia eventually appearing on day 8 post inoculation. Identification of ALKV-RNA in the cell culture was confirmed with RT-PCR and IFA. The virus titre was 3.2×10(6) tissue culture infective dose 50 (TCID(50)) per mL. Three more viral passages were successfully made in the C6/36 cells. This is the first description of propagation of ALKV in mosquito cells. PMID:22154975

  8. Anti-tumour activity of oncolytic Western Reserve vaccinia viruses in canine tumour cell lines, xenografts, and fresh tumour biopsies.

    Science.gov (United States)

    Autio, K; Knuuttila, A; Kipar, A; Ahonen, M; Parviainen, S; Diaconu, I; Kanerva, A; Hakonen, T; Vähä-Koskela, M; Hemminki, A

    2014-10-10

    Cancer is one of the most common reasons for death in dogs. One promising approach is oncolytic virotherapy. We assessed the oncolytic effect of genetically modified vaccinia viruses in canine cancer cells, in freshly excised tumour biopsies, and in mice harbouring canine tumour xenografts. Tumour transduction efficacy was assessed using virus expressing luciferase or fluorescent marker genes and oncolysis was quantified by a colorimetric cell viability assay. Oncolytic efficacy in vivo was evaluated in a nude mouse xenograft model. Vaccinia virus was shown to infect most tested canine cancer cell lines and primary surgical tumour tissues. Virus infection significantly reduced tumour growth in the xenograft model. Oncolytic vaccinia virus has antitumour effects against canine cancer cells and experimental tumours and is able to replicate in freshly excised patient tumour tissue. Our results suggest that oncolytic vaccinia virus may offer an effective treatment option for otherwise incurable canine tumours. PMID:25302859

  9. High Frequency of Virus-Specific CD8+ T Cells in the Central Nervous System of Macaques Chronically Infected with Simian Immunodeficiency Virus SIVmac251

    OpenAIRE

    Moniuszko, Marcin; Brown, Charlie; Pal, Ranajit; Tryniszewska, Elzbieta; Tsai, Wen-Po; Hirsch, Vanessa M.; Franchini, Genoveffa

    2003-01-01

    Infection with human immunodeficiency virus or simian immunodeficiency virus (SIV) induces virus-specific CD8+ T cells that traffic to lymphoid and nonlymphoid tissues. In this study, we used Gag-specific tetramer staining to investigate the frequency of CD8+ T cells in peripheral blood and the central nervous system of Mamu-A*01-positive SIV-infected rhesus macaques. Most of these infected macaques were vaccinated prior to SIVmac251 exposure. The frequency of Gag181-189 CM9 tetramer-positive...

  10. Association between Virus-Specific T-Cell Responses and Plasma Viral Load in Human Immunodeficiency Virus Type 1 Subtype C Infection

    OpenAIRE

    Novitsky, Vladimir A.; Gilbert, P; T. Peter; McLane, Mary Frances; Gaolekwe, S.; Rybak, N.; Thior, Ibou; Ndung, T.; Marlink, Richard G.; Lee, Tae Ho; Essex, Myron Elmer

    2003-01-01

    Virus-specific T-cell immune responses are important in restraint of human immunodeficiency virus type 1 (HIV-1) replication and control of disease. Plasma viral load is a key determinant of disease progression and infectiousness in HIV infection. Although HIV-1 subtype C (HIV-1C) is the predominant virus in the AIDS epidemic worldwide, the relationship between HIV-1C-specific T-cell immune responses and plasma viral load has not been elucidated. In the present study we address (i) the associ...

  11. Sialic Acids on Varicella-Zoster Virus Glycoprotein B Are Required for Cell-Cell Fusion.

    Science.gov (United States)

    Suenaga, Tadahiro; Matsumoto, Maki; Arisawa, Fuminori; Kohyama, Masako; Hirayasu, Kouyuki; Mori, Yasuko; Arase, Hisashi

    2015-08-01

    Varicella-zoster virus (VZV) is a member of the human Herpesvirus family that causes varicella (chicken pox) and zoster (shingles). VZV latently infects sensory ganglia and is also responsible for encephalomyelitis. Myelin-associated glycoprotein (MAG), a member of the sialic acid (SA)-binding immunoglobulin-like lectin family, is mainly expressed in neural tissues. VZV glycoprotein B (gB) associates with MAG and mediates membrane fusion during VZV entry into host cells. The SA requirements of MAG when associating with its ligands vary depending on the specific ligand, but it is unclear whether the SAs on gB are involved in the association with MAG. In this study, we found that SAs on gB are essential for the association with MAG as well as for membrane fusion during VZV infection. MAG with a point mutation in the SA-binding site did not bind to gB and did not mediate cell-cell fusion or VZV entry. Cell-cell fusion and VZV entry mediated by the gB-MAG interaction were blocked by sialidase treatment. N-glycosylation or O-glycosylation inhibitors also inhibited the fusion and entry mediated by gB-MAG interaction. Furthermore, gB with mutations in N-glycosylation sites, i.e. asparagine residues 557 and 686, did not associate with MAG, and the cell-cell fusion efficiency was low. Fusion between the viral envelope and cellular membrane is essential for host cell entry by herpesviruses. Therefore, these results suggest that SAs on gB play important roles in MAG-mediated VZV infection. PMID:26105052

  12. The generation of CD8+ T-cell population specific for vaccinia virus epitope involved in the antiviral protection against ectromelia virus challenge.

    Science.gov (United States)

    Gierynska, Malgorzata; Szulc-Dabrowska, Lidia; Dzieciatkowski, Tomasz; Golke, Anna; Schollenberger, Ada

    2015-12-01

    Eradication of smallpox has led to cessation of vaccination programs. This has rendered the human population increasingly susceptible not only to variola virus infection but also to infections with other representatives of Poxviridae family that cause zoonotic variola-like diseases. Thus, new approaches for designing improved vaccine against smallpox are required. Discovering that orthopoxviruses, e.g. variola virus, vaccinia virus, ectromelia virus, share common immunodominant antigen, may result in the development of such a vaccine. In our study, the generation of antigen-specific CD8(+) T cells in mice during the acute and memory phase of the immune response was induced using the vaccinia virus immunodominant TSYKFESV epitope and CpG oligodeoxynucleotides as adjuvants. The role of the generated TSYKFESV-specific CD8(+) T cells was evaluated in mice during ectromelia virus infection using systemic and mucosal model. Moreover, the involvement of dendritic cells subsets in the adaptive immune response stimulation was assessed. Our results indicate that the TSYKFESV epitope/TLR9 agonist approach, delivered systemically or mucosally, generated strong CD8(+) T-cell response when measured 10 days after immunization. Furthermore, the TSYKFESV-specific cell population remained functionally active 2 months post-immunization, and gave cross-protection in virally challenged mice, even though the numbers of detectable antigen-specific T cells decreased. PMID:26474845

  13. Expression of the A56 and K2 Proteins Is Sufficient To Inhibit Vaccinia Virus Entry and Cell Fusion▿ †

    OpenAIRE

    Wagenaar, Timothy R.; Moss, Bernard

    2008-01-01

    Many animal viruses induce cells to fuse and form syncytia. For vaccinia virus, this phenomenon is associated with mutations affecting the A56 and K2 proteins, which form a multimer (A56/K2) on the surface of infected cells. Recent evidence that A56/K2 interacts with the entry/fusion complex (EFC) and that the EFC is necessary for syncytium formation furnishes a strong connection between virus entry and cell fusion. Among the important remaining questions are whether A56/K2 can prevent virus ...

  14. Production of CCHF Virus-Like Particle by a Baculovirus-Insect Cell Expression System

    Institute of Scientific and Technical Information of China (English)

    Zhao-rui Zhou; Man-li Wang; Fei Deng; Tian-xian Li; Zhi-hong Hu; Hua-fin Wang

    2011-01-01

    Crimean-Congo Haemorrhagic Fever Virus(CCHFV)is a tick-born virus of the Nairovirus genus within the Bunyaviridae family,which is widespread and causes,high fatality. The nucleocapsid of CCHFV is comprised of N proteins that are encoded by the S segment. In this research,the N protein of CCHFV was expressed in insect cells using a recombinant baculovirus. Under an electron microscope,Virus-Like Particles (VLPs)with various size and morphology were observed in cytoplasmic vesicles in the infected cells.Sucrose-gradient purification of the cell lysate indicated that the VLPs were mainly located in the upper fraction after ultracentrifugation,which was confirmed by Western blot analysis and immuno-electron microscopy(IEM).

  15. The scaffolding protein Dlg1 is a negative regulator of cell-free virus infectivity but not of cell-to-cell HIV-1 transmission in T cells.

    Directory of Open Access Journals (Sweden)

    Patrycja Nzounza

    Full Text Available BACKGROUND: Cell-to-cell virus transmission of Human immunodeficiency virus type-1 (HIV-1 is predominantly mediated by cellular structures such as the virological synapse (VS. The VS formed between an HIV-1-infected T cell and a target T cell shares features with the immunological synapse (IS. We have previously identified the human homologue of the Drosophila Discs Large (Dlg1 protein as a new cellular partner for the HIV-1 Gag protein and a negative regulator of HIV-1 infectivity. Dlg1, a scaffolding protein plays a key role in clustering protein complexes in the plasma membrane at cellular contacts. It is implicated in IS formation and T cell signaling, but its role in HIV-1 cell-to-cell transmission was not studied before. METHODOLOGY/PRINCIPAL FINDINGS: Kinetics of HIV-1 infection in Dlg1-depleted Jurkat T cells show that Dlg1 modulates the replication of HIV-1. Single-cycle infectivity tests show that this modulation does not take place during early steps of the HIV-1 life cycle. Immunofluorescence studies of Dlg1-depleted Jurkat T cells show that while Dlg1 depletion affects IS formation, it does not affect HIV-1-induced VS formation. Co-culture assays and quantitative cell-to-cell HIV-1 transfer analyses show that Dlg1 depletion does not modify transfer of HIV-1 material from infected to target T cells, or HIV-1 transmission leading to productive infection via cell contact. Dlg1 depletion results in increased virus yield and infectivity of the viral particles produced. Particles with increased infectivity present an increase in their cholesterol content and during the first hours of T cell infection these particles induce higher accumulation of total HIV-1 DNA. CONCLUSION: Despite its role in the IS formation, Dlg1 does not affect the VS and cell-to-cell spread of HIV-1, but plays a role in HIV-1 cell-free virus transmission. We propose that the effect of Dlg1 on HIV-1 infectivity is at the stage of virus entry.

  16. Assessment of humoral and cell-mediated immune response to measles–mumps–rubella vaccine viruses among patients with asthma

    OpenAIRE

    Yoo, Kwang Ha; Agarwal, Kanishtha; Butterfield, Michael; Jacobson, Robert M.; Poland, Gregory A.; Juhn, Young J.

    2010-01-01

    Little is known about the influence of asthma status on humoral and cell-mediated immune responses to measles–mumps–rubella (MMR) vaccine viruses. We compared the virus-specific IgG levels and lymphoproliferative response of peripheral blood mononuclear cells to MMR vaccine viruses between asthmatic and nonasthmatic patients. The study subjects included 342 healthy children aged 12–18 years who had received two doses of the MMR vaccine. We ascertained asthma status by applying predetermined c...

  17. Comparative analysis of transcriptomic and hormonal responses to compatible and incompatible plant-virus interactions that lead to cell death

    OpenAIRE

    Pacheco, Remedios; García Marcos, Alberto; Manzano, Aranzazu; García de Lacoba, Mario; Camañes Querol, Gemma; García Agustín, Pilar; Díaz Ruíz, José Ramón; Tenllado, Francisco

    2012-01-01

    Hypersensitive response-related programmed cell death (PCD) has been extensively analyzed in various plant-virus interactions. However, little is known about the changes in gene expression and phytohormone levels associated with cell death caused by compatible viruses. The synergistic interaction of Potato virus X (PVX) with a number of Potyvirus spp. results in increased symptoms that lead to systemic necrosis (SN) in Nicotiana benthamiana. Here, we show that SN induced by a PVX recombinant ...

  18. Detection of human enteric viruses in stream water with RT-PCR and cell culture.

    Science.gov (United States)

    Denis-Mize, K.; Fout, G.S.; Dahling, D.R.; Francy, D.S.

    2004-01-01

    A multiplex RT-PCR method was used to measure virus occurrence at five stream water sites that span a range of hydroclimatic, water-quality, and land-use characteristics. The performance of the molecular method was evaluated in comparison with traditional cell culture and Escherichia coli membrane filtration assays. The study incorporated multiple quality controls and included a control for virus recovery during the sampling procedure as well as controls to detect potentially false-negative and false-positive data. Poliovirus recovery ranged from 16 to 65% and was variable, even in samples collected within the same stream. All five sites were positive for viruses by both molecular and cell culture-based virus assays. Enteroviruses, reoviruses, rotaviruses, and hepatitis A viruses were detected, but the use of the quality controls proved critical for interpretation of the molecular data. All sites showed evidence of faecal contamination, and culturable viruses were detected in four samples that would have met the US Environmental Protection Agency's recommended E. coli guideline for safe recreational water.

  19. Rapid preparation of plasma membranes from avian lymphoid cells and fibroblasts for virus binding studies.

    Science.gov (United States)

    Nieper, H; Müller, H

    1998-06-01

    A simple and rapid protocol for the preparation of plasma membranes from chicken embryo fibroblasts and chicken lymphoid cells was developed. Characterization of the preparations by morphological, biochemical and serological methods indicated the specific enrichment of the plasma membranes as well as cell surface proteins. Binding of infectious bursal disease virus (IBDV) particles was demonstrated after immobilization of the plasma membranes, and cell type-specific differences were observed. Although the results of these studies reflect the interaction between IBDV and isolated cells only partially, the advantages of these plasma membrane preparations, the specific enrichment of cell surface proteins, their constant quality and the possibility to store aliquots over several months, make them a useful tool for virus binding studies with avian cells. PMID:9694323

  20. Simplified Bryostatin Analogues Protect Cells from Chikungunya Virus-Induced Cell Death.

    Science.gov (United States)

    Staveness, Daryl; Abdelnabi, Rana; Schrier, Adam J; Loy, Brian A; Verma, Vishal A; DeChristopher, Brian A; Near, Katherine E; Neyts, Johan; Delang, Leen; Leyssen, Pieter; Wender, Paul A

    2016-04-22

    Chikungunya virus (CHIKV) is a mosquito-borne alphavirus showing a recent resurgence and rapid spread worldwide. While vaccines are under development, there are currently no therapies to treat this disease, except for over-the-counter (OTC) analgesics, which alleviate the devastating arthritic and arthralgic symptoms. To identify novel inhibitors of the virus, analogues of the natural product bryostatin 1, a clinical lead for the treatment of cancer, Alzheimer's disease, and HIV eradication, were investigated for in vitro antiviral activity and were found to be among the most potent inhibitors of CHIKV replication reported to date. Bryostatin-based therapeutic efforts and even recent anti-CHIKV strategies have centered on modulation of protein kinase C (PKC). Intriguingly, while the C ring of bryostatin primarily drives interactions with PKC, A- and B-ring functionality in these analogues has a significant effect on the observed cell-protective activity. Significantly, bryostatin 1 itself, a potent pan-PKC modulator, is inactive in these assays. These new findings indicate that the observed anti-CHIKV activity is not solely mediated by PKC modulation, suggesting possible as yet unidentified targets for CHIKV therapeutic intervention. The high potency and low toxicity of these bryologs make them promising new leads for the development of a CHIKV treatment. PMID:26900625

  1. Enhanced replication of UV-damaged Simian virus 40 DNA in carcinogen-treated mammalian cells

    International Nuclear Information System (INIS)

    The replication of UV-damaged Simian virus 40 (SV40) in carcinogen-treated monkey cells has been studied to elucidate the mechanism of carcinogen-enhanced reactivation. Carcinogen enhanced reactivation is the observed increase in UV-irradiated virus survival in host cells treated with low doses of carcinogen compared to UV-irradiated virus survival in untreated hosts. Carcinogen treatment of monkey kidney cells with either N-acetoxy-2-acetylaminofluorene (AAAF) or UV radiation leads to an enhanced capacity to replicate UV-damaged virus during the first round of infection. To further define the mechanism leading to enhanced replication, a detailed biochemical analysis of replication intermediates in carcinogen-treated cells was performed. Several conclusions can be drawn. First enhanced replication can be observed in the first four rounds of replication after UV irradiation of viral templates. The second major finding is that the relaxed circular intermediate model proposed for the replication of UV-damaged templates in untreated cells appears valid for replication of UV-damaged templates in carcinogen-treated cells. Possible mechanisms and the supporting evidence are discussed and future experiments outlined

  2. Porcine aminopeptidase N mediated polarized infection by porcine epidemic diarrhea virus in target cells

    International Nuclear Information System (INIS)

    Infection of polarized intestinal epithelial cells by porcine epidemic diarrhea virus (PEDV) was characterized. Indirect immunofluorescence assay, real-time PCR, and transmission electron microscopy confirmed PEDV can be successfully propagated in immortalized swine small intestine epithelial cells (IECs). Infection involved porcine aminpeptidase N (pAPN), a reported cellular receptor for PEDV, transient expression of pAPN and siRNA targeted pAPN increased and decreased the infectivity of PEDV in IECs, respectively. Subsequently, polarized entry into and release from both Vero E6 and IECs was analyzed. PEDV entry into polarized cells and pAPN grown on membrane inserts occurs via apical membrane. The progeny virus released into the medium was also quantified which demonstrated that PEDV is preferentially released from the apical membrane. Collectively, our data demonstrate that pAPN, the cellular receptor for PEDV, mediates polarized PEDV infection. These results imply the possibility that PEDV infection may proceed by lateral spread of virus in intestinal epithelial cells. - Highlights: • PEDV infection of polarized intestinal epithelial cells (IECs) was characterized. • Porcine aminpeptidase N (pAPN) facilitated PEDV infection in IECs. • PEDV entry into and release from polarized cell via its apical membrane. • PEDV infection may proceed by lateral spread of virus in IECs

  3. Egg drop syndrome virus enters duck embryonic fibroblast cells via clathrin-mediated endocytosis.

    Science.gov (United States)

    Huang, Jingjing; Tan, Dan; Wang, Yang; Liu, Caihong; Xu, Jiamin; Wang, Jingyu

    2015-12-01

    Previous studies of egg drop syndrome virus (EDSV) is restricted to serological surveys, disease diagnostics, and complete viral genome analysis. Consequently, the infection characteristics and entry routes of EDSV are poorly understood. Therefore, we aimed to explore the entry pathway of EDSV into duck embryonic fibroblast (DEF) cells as well as the infection characteristics and proliferation of EDSV in primary DEF and primary chicken embryo liver (CEL) cells. Transmission electron microscopy revealed that the virus triggered DEF cell membrane invagination as early as 10 min post-infection and that integrated endocytic vesicles formed at 20 min post-infection. The virus yield in EDSV-infected DEF cells treated with chlorpromazine (CPZ), sucrose, methyl-β-cyclodextrin (MβCD), or NH4Cl was measured by quantitative real-time PCR. Compared with the mock treatment, CPZ and sucrose greatly inhibited the production of viral progeny in a dose-dependent manner, while MβCD treatment did not result in a significant difference. Furthermore, NH4Cl had a strong inhibitory effect on the production of EDSV progeny. In addition, indirect immunofluorescence demonstrated that virus particles clustered on the surface of DEF cells treated with CPZ or sucrose. These results indicate that EDSV enters DEF cells through clathrin-mediated endocytosis followed by a pH-dependent step, which is similar to the mechanism of entry of human adenovirus types 2 and 5. PMID:26200954

  4. Adaptation of infectious bronchitis virus in primary cells of the chick embryo chorioallantoic membrane

    Directory of Open Access Journals (Sweden)

    M. H. Mohammed

    2013-06-01

    Full Text Available The susceptibility of the primary chick embryo chorioallontoic membrane cells to infectious bronchitis virus was evaluated after twenty consecutive passages in chick embryo chorioallontoic membrane cells. Virus replication was monitored by cytopathic observation, indirect immunoperoxidase, and reverse transcription polymerase chain reaction (RT-PCR. At 72 hours post-infection (p.i. in third passage, the cytopathic effect was characterized by rounding up of cells, monolayer detachment, intracytoplasmic brownish colouration was readily observed by immunoperoxidase from 24 hours p.i in third passage, and at all times the extracted viral RNA from IBV-infected monolayers was demonstrated by RT-PCR. Tissue culture ineffective dose50 (TCID50 was used to measure virus titration performed on primary chick embryo chorioallontoic membrane cells and the titre in twenty passage was 108.6 TCID50/ml. The results obtained in this study suggested that the primary chick embryo chorioallontoic membrane cells can be used for adaptation infectious bronchitis virus (IBV and may be considered a step forward for the use of these cells in the future for IBV vaccine production

  5. Porcine aminopeptidase N mediated polarized infection by porcine epidemic diarrhea virus in target cells

    Energy Technology Data Exchange (ETDEWEB)

    Cong, Yingying; Li, Xiaoxue; Bai, Yunyun [College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030 (China); Lv, Xiaonan [College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030 (China); CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience & Technology of China, Beijing 100090 (China); Herrler, Georg [Institute for Virology, University of Veterinary Medicine, Hannover D-30559 (Germany); Enjuanes, Luis [Department of Molecular and Cell Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus Universidad Autónoma de Madrid, Cantoblanco, Madrid (Spain); Zhou, Xingdong [College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030 (China); Qu, Bo [Faculty of Life Sciences, Northeast Agricultural University, Harbin 150030 (China); Meng, Fandan [Institute for Virology, University of Veterinary Medicine, Hannover D-30559 (Germany); Cong, Chengcheng [College Animal Husbandry and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110161 (China); Ren, Xiaofeng; Li, Guangxing [College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030 (China)

    2015-04-15

    Infection of polarized intestinal epithelial cells by porcine epidemic diarrhea virus (PEDV) was characterized. Indirect immunofluorescence assay, real-time PCR, and transmission electron microscopy confirmed PEDV can be successfully propagated in immortalized swine small intestine epithelial cells (IECs). Infection involved porcine aminpeptidase N (pAPN), a reported cellular receptor for PEDV, transient expression of pAPN and siRNA targeted pAPN increased and decreased the infectivity of PEDV in IECs, respectively. Subsequently, polarized entry into and release from both Vero E6 and IECs was analyzed. PEDV entry into polarized cells and pAPN grown on membrane inserts occurs via apical membrane. The progeny virus released into the medium was also quantified which demonstrated that PEDV is preferentially released from the apical membrane. Collectively, our data demonstrate that pAPN, the cellular receptor for PEDV, mediates polarized PEDV infection. These results imply the possibility that PEDV infection may proceed by lateral spread of virus in intestinal epithelial cells. - Highlights: • PEDV infection of polarized intestinal epithelial cells (IECs) was characterized. • Porcine aminpeptidase N (pAPN) facilitated PEDV infection in IECs. • PEDV entry into and release from polarized cell via its apical membrane. • PEDV infection may proceed by lateral spread of virus in IECs.

  6. A plant vacuolar protease, VPE, mediates virus-induced hypersensitive cell death.

    Science.gov (United States)

    Hatsugai, Noriyuki; Kuroyanagi, Miwa; Yamada, Kenji; Meshi, Tetsuo; Tsuda, Shinya; Kondo, Maki; Nishimura, Mikio; Hara-Nishimura, Ikuko

    2004-08-01

    Programmed cell death (PCD) in animals depends on caspase protease activity. Plants also exhibit PCD, for example as a response to pathogens, although a plant caspase remains elusive. Here we show that vacuolar processing enzyme (VPE) is a protease essential for a virus-induced hypersensitive response that involves PCD. VPE deficiency prevented virus-induced hypersensitive cell death in tobacco plants. VPE is structurally unrelated to caspases, although VPE has a caspase-1 activity. Thus, plants have evolved a regulated cellular suicide strategy that, unlike PCD of animals, is mediated by VPE and the cellular vacuole. PMID:15297671

  7. Potential cellular receptors involved in hepatitis C virus entry into cells

    Directory of Open Access Journals (Sweden)

    Muellhaupt Beat

    2005-04-01

    Full Text Available Abstract Hepatitis C virus (HCV infects hepatocytes and leads to permanent, severe liver damage. Since the genomic sequence of HCV was determined, progress has been made towards understanding the functions of the HCV-encoded proteins and identifying the cellular receptor(s responsible for adsorption and penetration of the virus particle into the target cells. Several cellular receptors for HCV have been proposed, all of which are associated with lipid and lipoprotein metabolism. This article reviews the cellular receptors for HCV and suggests a general model for HCV entry into cells, in which lipoproteins play a crucial role.

  8. Packaging cells for avian leukosis virus-based vectors with various host ranges.

    OpenAIRE

    Cosset, F L; Ronfort, C.; Molina, R. M.; Flamant, F.; Drynda, A; Benchaibi, M; Valsesia, S; Nigon, V M; Verdier, G

    1992-01-01

    Using our previously described Haydée semipackaging cell line (F. L. Cosset, C. Legras, Y. Chebloune, P. Savatier, P. Thoraval, J. L. Thomas, J. Samarut, V. M. Nigon, and G. Verdier, J. Virol. 64:1070-1078, 1990) which produces avian leukosis virus gag and pol proteins, we have constructed packaging cells with subgroups B, C, and E envelope specificities. This allows us to produce helper-free avian leukosis virus particles carrying the lacZ reporter gene and the A, B, C, or E subgroup specifi...

  9. Antioxidants Enhancement to the Immune Response of NIH Mice to Vero Cell Grown Rabies Virus Vaccine

    OpenAIRE

    Aly Fahmy Mohamed

    2006-01-01

    Introduction: Rabies cell culture vaccine (Vero-Rab) showed to be more immunogenic and a higher and faster release of antibody titer could be detected than in case of using Fermi type vaccine, DEV and CECV. Result: The immune response of NIH mice immunized intramuscularly using both vE - Se adjuvated and non adjuvated Vero cell rabies virus vaccine (Vero-Rab) showed an elevation of antibody level of vaccinated mice groups more than the limits decided by WHO for a potent rabies virus vaccine. ...

  10. Multiple Effector Functions Mediated by Human Immunodeficiency Virus-Specific CD4+ T-Cell Clones

    OpenAIRE

    Norris, Philip J.; Sumaroka, Marina; Brander, Christian; Moffett, Howell F.; Boswell, Steven L.; Nguyen, Tam; Sykulev, Yuri; Walker, Bruce D; Rosenberg, Eric S.

    2001-01-01

    Mounting evidence suggests that human immunodeficiency virus type 1 (HIV-1) Gag-specific T helper cells contribute to effective antiviral control, but their functional characteristics and the precise epitopes targeted by this response remain to be defined. In this study, we generated CD4+ T-cell clones specific for Gag from HIV-1-infected persons with vigorous Gag-specific responses detectable in peripheral blood mononuclear cells. Multiple peptides containing T helper epitopes were identifie...

  11. The mechanism of Epstein-Barr virus infection in nasopharyngeal carcinoma cells.

    OpenAIRE

    Lin, C T; Lin, C. R.; Tan, G. K.; Chen, W.; Dee, A. N.; Chan, W Y

    1997-01-01

    To investigate the relationship between Epstein-Barr virus (EBV) and nasopharyngeal carcinoma (NPC) cells, we examined the pathway of EBV infection in NPC cell lines. We used immunolocalization to investigate the EBV receptor (C3d-R) and polymeric immunoglobulin receptor [secretory component (SC) protein]. We incubated IgA anti-EBV and EBV particles with NPC cells and observed the EBV DNA signal by in situ polymerase chain reaction hybridization and polymerase chain reaction plus Southern blo...

  12. Immunological characterization of proteins detected by phosphotyrosine antibodies in cells transformed by Rous sarcoma virus.

    OpenAIRE

    Linder, M E; Burr, J G

    1988-01-01

    Phosphotyrosine antibodies were used to identify tyrosine-phosphorylated proteins in Rous sarcoma virus (RSV)-transformed chicken embryo fibroblasts. A large number of tyrosine phosphoproteins were detected. A similar set of proteins was observed in RSV-transformed murine cells. An 85,000-dalton protein, however, was present in transformed avian cells but missing in transformed murine cells. Neither the 85,000-dalton protein nor any of the other tyrosine phosphoproteins appeared to be viral s...

  13. Ginseng Protects Against Respiratory Syncytial Virus by Modulating Multiple Immune Cells and Inhibiting Viral Replication

    OpenAIRE

    Jong Seok Lee; Yu-Na Lee; Young-Tae Lee; Hye Suk Hwang; Ki-Hye Kim; Eun-Ju Ko; Min-Chul Kim; Sang-Moo Kang

    2015-01-01

    Ginseng has been used in humans for thousands of years but its effects on viral infection have not been well understood. We investigated the effects of red ginseng extract (RGE) on respiratory syncytial virus (RSV) infection using in vitro cell culture and in vivo mouse models. RGE partially protected human epithelial (HEp2) cells from RSV-induced cell death and viral replication. In addition, RGE significantly inhibited the production of RSV-induced pro-inflammatory cytokine (TNF-α) in murin...

  14. Enumeration of the Simian Virus 40 Early Region Elements Necessary for Human Cell Transformation

    OpenAIRE

    Hahn, William C.; Scott K Dessain; Brooks, Mary W.; King, Jessie E.; Elenbaas, Brian; Sabatini, David M.; DeCaprio, James A.; Weinberg, Robert A.

    2002-01-01

    While it is clear that cancer arises from the accumulation of genetic mutations that endow the malignant cell with the properties of uncontrolled growth and proliferation, the precise combinations of mutations that program human tumor cell growth remain unknown. The study of the transforming proteins derived from DNA tumor viruses in experimental models of transformation has provided fundamental insights into the process of cell transformation. We recently reported that coexpression of the si...

  15. Blockade of Immunosuppressive Cytokines Restores NK Cell Antiviral Function in Chronic Hepatitis B Virus Infection

    OpenAIRE

    Dimitra Peppa; Lorenzo Micco; Alia Javaid; Kennedy, Patrick T.F.; Anna Schurich; Claire Dunn; Celeste Pallant; Gidon Ellis; Pooja Khanna; Geoffrey Dusheiko; Gilson, Richard J.; Mala K Maini

    2010-01-01

    NK cells are enriched in the liver, constituting around a third of intrahepatic lymphocytes. We have previously demonstrated that they upregulate the death ligand TRAIL in patients with chronic hepatitis B virus infection (CHB), allowing them to kill hepatocytes bearing TRAIL receptors. In this study we investigated whether, in addition to their pathogenic role, NK cells have antiviral potential in CHB. We characterised NK cell subsets and effector function in 64 patients with CHB compared to...

  16. Human immunodeficiency virus-1 gp120 and gp160 envelope proteins modulate mesangial cell gelatinolytic activity.

    OpenAIRE

    Singhal, P. C.; Sagar, S.; D. Chandra; Garg, P

    1995-01-01

    Patients with human immunodeficiency virus (HIV) infection often develop glomerular lesions (mesangial expansion and sclerosis). Modulation of matrix degradation may be important in the expansion of the mesangium. We studied the effect of HIV sera and HIV-1 envelope glycoproteins on gelatinolytic activity of human mesangial cells. HIV serum-treated cells showed lower (P < 0.01) gelatinolytic activity when compared with cells treated with control serum (control serum, 4.3 +/- 0.1 versus HIV se...

  17. Hepatitis B virus produced by transfected Hep G2 cells causes hepatitis in chimpanzees.

    OpenAIRE

    Acs, G; Sells, M. A.; Purcell, R H; Price, P; Engle, R; Shapiro, M.; Popper, H.

    1987-01-01

    We have reported that clonal cells derived from Hep G2 cells transfected with a plasmid containing hepatitis B virus (HBV) DNA secrete spherical and filamentous forms of hepatitis B surface antigen (HBsAg), core particles, and virions into the culture medium. Here we describe the development of typical hepatitis in two chimpanzees following intravenous inoculation with the medium in which the transfected cells had grown. The liver biopsies from these animals showed characteristic lesions in p...

  18. Cellular mechanisms of alpha herpesvirus egress: live cell fluorescence microscopy of pseudorabies virus exocytosis.

    OpenAIRE

    Hogue, Ian B.; Jens B Bosse; Jiun-Ruey Hu; Thiberge, Stephan Y.; Enquist, Lynn W.

    2014-01-01

    Egress of newly assembled herpesvirus particles from infected cells is a highly dynamic process involving the host secretory pathway working in concert with viral components. To elucidate the location, dynamics, and molecular mechanisms of alpha herpesvirus egress, we developed a live-cell fluorescence microscopy method to visualize the final transport and exocytosis of pseudorabies virus (PRV) particles in non-polarized epithelial cells. This method is based on total internal reflection fluo...

  19. Detection and quantitation of human immunodeficiency virus-infected peripheral blood mononuclear cells by flow cytometry.

    OpenAIRE

    McSharry, J J; Costantino, R; Robbiano, E; Echols, R; Stevens, R; Lehman, J M

    1990-01-01

    A flow cytometric assay has been developed to detect and quantitate human immunodeficiency virus (HIV)-infected peripheral blood mononuclear cells obtained from HIV-seropositive patients. Peripheral blood was obtained from patients attending an acquired immune deficiency syndrome clinic, and mononuclear cells were separated by centrifugation onto Ficoll-Hypaque. The cell layer at the interface was removed, washed in phosphate-buffered saline without Ca2+ and Mg2+, and fixed with 90% methanol,...

  20. The Epstein-Barr Virus (EBV) in T Cell and NK Cell Lymphomas: Time for a Reassessment

    Science.gov (United States)

    Gru, A. A.; Haverkos, B. H.; Freud, A. G.; Hastings, J.; Nowacki, N. B.; Barrionuevo, C.; Vigil, C. E.; Rochford, R.; Natkunam, Y.; Baiocchi, R. A.

    2015-01-01

    While Epstein-Barr virus (EBV) was initially discovered and characterized as an oncogenic virus in B cell neoplasms, it also plays a complex and multifaceted role in T/NK cell lymphomas. In B cell lymphomas, EBV-encoded proteins have been shown to directly promote immortalization and proliferation through stimulation of the NF-κB pathway and increased expression of anti-apoptotic genes. In the context of mature T/NK lymphomas (MTNKL), with the possible exception on extranodal NK/T cell lymphoma (ENKTL), the virus likely plays a more diverse and nuanced role. EBV has been shown to shape the tumor microenvironment by promoting Th2-skewed T cell responses and by increasing the expression of the immune checkpoint ligand PD-L1. The type of cell infected, the amount of plasma EBV DNA, and the degree of viral lytic replication have all been proposed to have prognostic value in T/NK cell lymphomas. Latency patterns of EBV infection have been defined using EBV-infected B cell models and have not been definitively established in T/NK cell lymphomas. Identifying the expression profile of EBV lytic proteins could allow for individualized therapy with the use of antiviral medications. More work needs to be done to determine whether EBV-associated MTNKL have distinct biological and clinical features, which can be leveraged for risk stratification, disease monitoring, and therapeutic purposes. PMID:26449716