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Sample records for latently infected cell

  1. The Role of Latently Infected B Cells in CNS Autoimmunity

    PubMed Central

    Márquez, Ana Citlali; Horwitz, Marc Steven

    2015-01-01

    The onset of multiple sclerosis (MS) is caused by both genetic and environmental factors. Among the environmental factors, it is believed that previous infection with Epstein–Barr virus (EBV) may contribute in the development of MS. EBV has been associated with other autoimmune diseases, such as systemic lupus erythematous, and cancers like Burkitt’s lymphoma. EBV establishes a life-long latency in B cells with occasional reactivation of the virus throughout the individual’s life. The role played by B cells in MS pathology has been largely studied, yet is not clearly understood. In MS patients, Rituximab, a novel treatment that targets CD20+ B cells, has proven to have successful results in diminishing the number of relapses in remitting relapsing MS; however, the mechanism of how this drug acts has not been clearly established. In this review, we analyze the evidence of how B cells latently infected with EBV might be altering the immune system response and helping in the development of MS. We will also discuss how animal models, such as experimental autoimmune encephalomyelitis (EAE) and murine gammaherpesvirus-68 (γHV-68), can be used as powerful tools in the study of the relationship between EBV, MS, and B cells. PMID:26579121

  2. Peripheral Vγ9Vδ2 T Cells Are a Novel Reservoir of Latent HIV Infection

    PubMed Central

    Soriano-Sarabia, Natalia; Archin, Nancie M.; Bateson, Rosalie; Dahl, Noelle P.; Crooks, Amanda M.; Kuruc, JoAnn D.; Garrido, Carolina; Margolis, David M.

    2015-01-01

    Eradication of HIV infection will require the identification of all cellular reservoirs that harbor latent infection. Despite low or lack of CD4 receptor expression on Vδ2 T cells, infection of these cells has previously been reported. We found that upregulation of the CD4 receptor may render primary Vδ2 cells target for HIV infection in vitro and we propose that HIV-induced immune activation may allow infection of γδ T cells in vivo. We assessed the presence of latent HIV infection by measurements of DNA and outgrowth assays within Vδ2 cells in 18 aviremic patients on long-standing antiretroviral therapy. In 14 patients we recovered latent but replication-competent HIV from highly purified Vδ2 cells demonstrating that peripheral Vδ2 T cells are a previously unrecognized reservoir in which latent HIV infection is unexpectedly frequent. PMID:26473478

  3. Electrical response of a B lymphoma cell line latently infected with Kaposi's sarcoma herpesvirus.

    PubMed

    Safavieh, Mohammadali; Khetani, Sultan; Juillard, Franceline; Kaul, Vivasvat; Kanakasabapathy, Manoj Kumar; Kaye, Kenneth M; Shafiee, Hadi

    2016-06-15

    Certain viruses, such as herpesviruses, are capable of persistent and latent infection of host cells. Distinguishing and separating live, latently infected cells from uninfected cells is not easily attainable using current approaches. The ability to perform such separation would greatly enhance the ability to study primary, infected cells and potentially enable elimination of latently infected cells from the host. Here, the dielectrophoretic response of B cells infected with Kaposi's sarcoma-associated herpesvirus (KSHV) were investigated and compared to uninfected B cells. We evaluated the effect of applied voltage, signal frequency, and flow rate of the sample on the cell capture efficiency. We achieved 37.1%±8.5% difference in capture efficiencies between latently KSHV-infected and uninfected BJAB B lymphoma cells at the chip operational conditions of 1V, 50kHz and 0.02μl/min sample flow rate. Our results show that latently infected B lymphoma cells demonstrated significantly different electrical response compared to uninfected B cells and DEP-based microchips can be potentially used for sorting latently infected cells based on their electrical properties. PMID:26851580

  4. Activation and lysis of human CD4 cells latently infected with HIV-1

    PubMed Central

    Pegu, Amarendra; Asokan, Mangaiarkarasi; Wu, Lan; Wang, Keyun; Hataye, Jason; Casazza, Joseph P.; Guo, Xiaoti; Shi, Wei; Georgiev, Ivelin; Zhou, Tongqing; Chen, Xuejun; O'Dell, Sijy; Todd, John-Paul; Kwong, Peter D.; Rao, Srinivas S.; Yang, Zhi-yong; Koup, Richard A.; Mascola, John R.; Nabel, Gary J.

    2015-01-01

    The treatment of AIDS with combination antiretroviral therapy (cART) remains lifelong largely because the virus persists in latent reservoirs. Elimination of latently infected cells could therefore reduce treatment duration and facilitate immune reconstitution. Here we report an approach to reduce the viral reservoir by activating dormant viral gene expression and directing T lymphocytes to lyse previously latent, HIV-1-infected cells. An immunomodulatory protein was created that combines the specificity of a HIV-1 broadly neutralizing antibody with that of an antibody to the CD3 component of the T-cell receptor. CD3 engagement by the protein can stimulate T-cell activation that induces proviral gene expression in latently infected T cells. It further stimulates CD8 T-cell effector function and redirects T cells to lyse these previously latent-infected cells through recognition of newly expressed Env. This immunomodulatory protein could potentially help to eliminate latently infected cells and deplete the viral reservoir in HIV-1-infected individuals. PMID:26485194

  5. Killing of Kaposi's sarcoma-associated herpesvirus-infected fibroblasts during latent infection by activated natural killer cells

    PubMed Central

    Matthews, Nick C; Goodier, Martin R; Robey, Rebecca C; Bower, Mark; Gotch, Frances M

    2011-01-01

    Abstract Kaposi's sarcoma-associated herpesvirus (KSHV) establishes life-long infection by evading clearance by the host immune system. In de novo infection and lytic replication, KSHV escapes cytotoxic T cells and NK cells through downregulation of MHC class-I and ICAM-1 molecules and associated antigens involved in forming and sustaining the immunological synapse. However, the efficacy of such mechanisms in the context of the predominantly latent KSHV infection reported in Kaposi's sarcoma (KS) lesions is unclear. Using primary dermal fibroblasts in a novel in vitro model of chronic latent KSHV infection, we generated target cells with viral loads similar to those in spindle cells extracted from KS lesions. We show that latently KSHV-infected fibroblasts had normal levels of MHC-class I, ICAM-1, HLA-E and NKG2D ligand expression, were resistant to NK-cell natural cytotoxicity and were highly susceptible to killing by cytokine-activated immunocompetent NK cells. KSHV-infected fibroblasts expressed normal levels of IFN-γR1 and responded to exogenous IFN-γ by upregulating MHC class I, ICAM-1 and HLA-E and resisting activated NK-cell killing. These data demonstrate that physiologically relevant levels of latent KSHV infection in primary cells cause limited activation of resting NK cells and confer little specific resistance to control by activated NK cells. PMID:21509779

  6. Signaling through Toll-like receptors triggers HIV-1 replication in latently infected mast cells.

    PubMed

    Sundstrom, J Bruce; Little, Dawn M; Villinger, Francois; Ellis, Jane E; Ansari, Aftab A

    2004-04-01

    Evidence that human progenitor mast cells are susceptible to infection with CCR5-tropic strains of HIV-1 and that circulating HIV-1-infected FcepsilonRIalpha(+) cells with a similar progenitor phenotype have been isolated from AIDS patients has led to speculation that mast cells may serve as a potential reservoir for infectious HIV-1. In this study, progenitor mast cells, developed in vitro from CD34(+) cord blood stem cells, were experimentally infected with the CCR5-tropic strain HIV-1Bal after 28 days in culture as they reached their HIV-1-susceptible progenitor stage. HIV-1 p24 Ag levels were readily detectable by day 7 postinfection (PI), peaked at 2-3 wk PI as mature (tryptase/chymase-positive) HIV-1 infection-resistant mast cells emerged, and then steadily declined to below detectable limits by 10 wk PI, at which point integrated HIV-1 proviral DNA was confirmed by PCR quantitation in ( approximately 34% of) latently infected mast cells. Stimulation by ligands for Toll-like receptor (TLR) 2, TLR4, or TLR9 significantly enhanced viral replication in a dose- and time-dependent manner in both HIV-1-infected progenitor and latently infected mature mast cells, without promoting degranulation, apoptosis, cellular proliferation, or dysregulation of TLR agonist-induced cytokine production in infected mast cells. Limiting dilution analysis of TLR activated, latently infected mature mast cells indicated that one in four was capable of establishing productive infections in A301 sentinel cells. Taken together, these results indicate that mast cells may serve both as a viral reservoir and as a model for studying mechanisms of postintegration latency in HIV infection. PMID:15034054

  7. Transient activation of human cytomegalovirus lytic gene expression during latency allows cytotoxic T cell killing of latently infected cells.

    PubMed

    Krishna, B A; Lau, B; Jackson, S E; Wills, M R; Sinclair, J H; Poole, E

    2016-01-01

    Human cytomegalovirus (HCMV) latency in the myeloid lineage is maintained by repressive histone modifications around the major immediate early promoter (MIEP), which results in inhibition of the lytic viral life cycle. We now show that pharmacological inhibition of histone deacetylases (HDACs) relieves this repression of the MIEP and induces transient expression of the viral lytic immediate early (IE) antigens but, importantly, not full virus reactivation. In turn, these latently infected cells now become targets for IE-specific cytotoxic T cells (CTLs) which are present at high frequency in all normal healthy HCMV positive carriers but would normally be unable to target latent (lytic antigen-negative) cells. This approach of transiently inducing viral lytic gene expression by HDAC inhibition, in otherwise latently infected cells, offers a window of opportunity to target and purge the latent myeloid cell reservoir by making these normally immunologically undetectable cells visible to pre-existing host immune responses to viral lytic antigens. PMID:27091512

  8. Transient activation of human cytomegalovirus lytic gene expression during latency allows cytotoxic T cell killing of latently infected cells

    PubMed Central

    Krishna, B. A.; Lau, B.; Jackson, S. E.; Wills, M. R.; Sinclair, J. H.; Poole, E.

    2016-01-01

    Human cytomegalovirus (HCMV) latency in the myeloid lineage is maintained by repressive histone modifications around the major immediate early promoter (MIEP), which results in inhibition of the lytic viral life cycle. We now show that pharmacological inhibition of histone deacetylases (HDACs) relieves this repression of the MIEP and induces transient expression of the viral lytic immediate early (IE) antigens but, importantly, not full virus reactivation. In turn, these latently infected cells now become targets for IE-specific cytotoxic T cells (CTLs) which are present at high frequency in all normal healthy HCMV positive carriers but would normally be unable to target latent (lytic antigen-negative) cells. This approach of transiently inducing viral lytic gene expression by HDAC inhibition, in otherwise latently infected cells, offers a window of opportunity to target and purge the latent myeloid cell reservoir by making these normally immunologically undetectable cells visible to pre-existing host immune responses to viral lytic antigens. PMID:27091512

  9. CD4 T Cell Responses in Latent and Chronic Viral Infections

    PubMed Central

    Walton, Senta; Mandaric, Sanja; Oxenius, Annette

    2013-01-01

    The spectrum of tasks which is fulfilled by CD4 T cells in the setting of viral infections is large, ranging from support of CD8 T cells and humoral immunity to exertion of direct antiviral effector functions. While our knowledge about the differentiation pathways, plasticity, and memory of CD4 T cell responses upon acute infections or immunizations has significantly increased during the past years, much less is still known about CD4 T cell differentiation and their beneficial or pathological functions during persistent viral infections. In this review we summarize current knowledge about the differentiation, direct or indirect antiviral effector functions, and the regulation of virus-specific CD4 T cells in the setting of persistent latent or active chronic viral infections with a particular emphasis on herpes virus infections for the former and chronic lymphocytic choriomeningitis virus infection for the latter. PMID:23717308

  10. Selected Drugs with Reported Secondary Cell-Differentiating Capacity Prime Latent HIV-1 Infection for Reactivation

    PubMed Central

    Shishido, Takao; Wolschendorf, Frank; Duverger, Alexandra; Wagner, Frederic; Kappes, John; Jones, Jennifer

    2012-01-01

    Reactivation of latent HIV-1 infection is considered our best therapeutic means to eliminate the latent HIV-1 reservoir. Past therapeutic attempts to systemically trigger HIV-1 reactivation using single drugs were unsuccessful. We thus sought to identify drug combinations consisting of one component that would lower the HIV-1 reactivation threshold and a synergistic activator. With aclacinomycin and dactinomycin, we initially identified two FDA-approved drugs that primed latent HIV-1 infection in T cell lines and in primary T cells for reactivation and facilitated complete reactivation at the population level. This effect was correlated not with the reported primary drug effects but with the cell-differentiating capacity of the drugs. We thus tested other cell-differentiating drugs/compounds such as cytarabine and aphidicolin and found that they also primed latent HIV-1 infection for reactivation. This finding extends the therapeutic promise of N′-N′-hexamethylene-bisacetamide (HMBA), another cell-differentiating agent that has been reported to trigger HIV-1 reactivation, into the group of FDA-approved drugs. To this end, it is also noteworthy that suberoylanilide hydroxamic acid (SAHA), a polar compound that was initially developed as a second-generation cell-differentiating agent using HMBA as a structural template and which is now marketed as the histone deacetylase (HDAC) inhibitor vorinostat, also has been reported to trigger HIV-1 reactivation. Our findings suggest that drugs with primary or secondary cell-differentiating capacity should be revisited as HIV-1-reactivating agents as some could potentially be repositioned as candidate drugs to be included in an induction therapy to trigger HIV-1 reactivation. PMID:22696646

  11. Selected drugs with reported secondary cell-differentiating capacity prime latent HIV-1 infection for reactivation.

    PubMed

    Shishido, Takao; Wolschendorf, Frank; Duverger, Alexandra; Wagner, Frederic; Kappes, John; Jones, Jennifer; Kutsch, Olaf

    2012-09-01

    Reactivation of latent HIV-1 infection is considered our best therapeutic means to eliminate the latent HIV-1 reservoir. Past therapeutic attempts to systemically trigger HIV-1 reactivation using single drugs were unsuccessful. We thus sought to identify drug combinations consisting of one component that would lower the HIV-1 reactivation threshold and a synergistic activator. With aclacinomycin and dactinomycin, we initially identified two FDA-approved drugs that primed latent HIV-1 infection in T cell lines and in primary T cells for reactivation and facilitated complete reactivation at the population level. This effect was correlated not with the reported primary drug effects but with the cell-differentiating capacity of the drugs. We thus tested other cell-differentiating drugs/compounds such as cytarabine and aphidicolin and found that they also primed latent HIV-1 infection for reactivation. This finding extends the therapeutic promise of N'-N'-hexamethylene-bisacetamide (HMBA), another cell-differentiating agent that has been reported to trigger HIV-1 reactivation, into the group of FDA-approved drugs. To this end, it is also noteworthy that suberoylanilide hydroxamic acid (SAHA), a polar compound that was initially developed as a second-generation cell-differentiating agent using HMBA as a structural template and which is now marketed as the histone deacetylase (HDAC) inhibitor vorinostat, also has been reported to trigger HIV-1 reactivation. Our findings suggest that drugs with primary or secondary cell-differentiating capacity should be revisited as HIV-1-reactivating agents as some could potentially be repositioned as candidate drugs to be included in an induction therapy to trigger HIV-1 reactivation. PMID:22696646

  12. Specific Elimination of Latently HIV-1 Infected Cells Using HIV-1 Protease-Sensitive Toxin Nanocapsules

    PubMed Central

    Wen, Jing; Yan, Ming; Liu, Yang; Li, Jie; Xie, Yiming; Lu, Yunfeng; Kamata, Masakazu; Chen, Irvin S. Y.

    2016-01-01

    Anti-retroviral drugs suppress HIV-1 plasma viremia to undetectable levels; however, latent HIV-1 persists in reservoirs within HIV-1-infected patients. The silent provirus can be activated through the use of drugs, including protein kinase C activators and histone deacetylase inhibitors. This “shock” approach is then followed by “kill” of the producing cells either through direct HIV-1-induced cell death or natural immune mechanisms. However, these mechanisms are relatively slow and effectiveness is unclear. Here, we develop an approach to specifically target and kill cells that are activated early in the process of virus production. We utilize a novel nanocapsule technology whereby the ricin A chain is encapsulated in an inactive form within a polymer shell. Specificity for release of the ricin A toxin is conferred by peptide crosslinkers that are sensitive to cleavage by HIV-1 protease. By using well-established latent infection models, J-Lat and U1 cells, we demonstrate that only within an HIV-1-producing cell expressing functional HIV-1 protease will the nanocapsule release its ricin A cargo, shutting down viral and cellular protein synthesis, and ultimately leading to rapid death of the producer cell. Thus, we provide proof of principle for a novel technology to kill HIV-1-producing cells without effects on non-target cells. PMID:27049645

  13. Specific Elimination of Latently HIV-1 Infected Cells Using HIV-1 Protease-Sensitive Toxin Nanocapsules.

    PubMed

    Wen, Jing; Yan, Ming; Liu, Yang; Li, Jie; Xie, Yiming; Lu, Yunfeng; Kamata, Masakazu; Chen, Irvin S Y

    2016-01-01

    Anti-retroviral drugs suppress HIV-1 plasma viremia to undetectable levels; however, latent HIV-1 persists in reservoirs within HIV-1-infected patients. The silent provirus can be activated through the use of drugs, including protein kinase C activators and histone deacetylase inhibitors. This "shock" approach is then followed by "kill" of the producing cells either through direct HIV-1-induced cell death or natural immune mechanisms. However, these mechanisms are relatively slow and effectiveness is unclear. Here, we develop an approach to specifically target and kill cells that are activated early in the process of virus production. We utilize a novel nanocapsule technology whereby the ricin A chain is encapsulated in an inactive form within a polymer shell. Specificity for release of the ricin A toxin is conferred by peptide crosslinkers that are sensitive to cleavage by HIV-1 protease. By using well-established latent infection models, J-Lat and U1 cells, we demonstrate that only within an HIV-1-producing cell expressing functional HIV-1 protease will the nanocapsule release its ricin A cargo, shutting down viral and cellular protein synthesis, and ultimately leading to rapid death of the producer cell. Thus, we provide proof of principle for a novel technology to kill HIV-1-producing cells without effects on non-target cells. PMID:27049645

  14. Photodynamic therapy induced production of cytokines by latent Epstein Barr virus infected epithelial tumor cells

    NASA Astrophysics Data System (ADS)

    Koon, H. K.; Lo, K. W.; Lung, M. L.; Chang, C. K. C.; Wong, R. N. S.; Mak, N. K.

    2007-02-01

    Photodynamic therapy (PDT) is a method to treat cancer or non-cancer diseases by activation of the light-sensitive photosensitizers. Epstein Barr virus (EBV) has been implicated in the development of certain cancers such as nasopharyngeal carcinoma and B cell lymphoma. This study aims to examine the effects of EBV infection on the production of pro-inflammatory cytokines and chemokines in cells after the photosensitizer Zn-BC-AM PDT treatment. Epithelial tumor cell lines HONE-1 and latent EBV-infected HONE-1 (EBV-HONE-1) cells were used in this study. Cells were treated with the photosensitizer Zn-BC-AM for 24 hours before light irradiation. RT-PCR and quantitative ELISA methods were used for the evaluation of mRNA expression and production of cytokines, respectively. Results show that Zn-BC-AM PDT increases the production of IL-1a and IL-1b in EBV-HONE-1. Over a 10-fold increase in the production of IL-6 was observed in the culture supernatant of Zn-BC-AM PDT-treated HONE-1 cells. PDT-induced IL-6 production was observed in HONE-1 cells. EBV-HONE-1 has a higher background level of IL-8 production than the HONE-1. The production of IL-8 was suppressed in EBV-HONE-1cells after Zn-BC-AM PDT. Our results indicate that the response of HONE-1 cells to Zn-BC-AM PDT depends on the presence of latent EBV infection. Since IL-8 is a cytokine with angiogenic activity, Zn-BC-AM PDT may exert an anti-angiogenic effect through the suppression of IL-8 production by the EBV-infected cells.

  15. Mycobacterium-Host Cell Relationships in Granulomatous Lesions in a Mouse Model of Latent Tuberculous Infection.

    PubMed

    Ufimtseva, Elena

    2015-01-01

    Tuberculosis (TB) is a dangerous infectious disease characterized by a tight interplay between mycobacteria and host cells in granulomatous lesions (granulomas) during the latent, asymptomatic stage of infection. Mycobacterium-host cell relationships were analyzed in granulomas obtained from various organs of BALB/c mice with chronic TB infection caused by in vivo exposure to the Bacillus Calmette-Guérin (BCG) vaccine. Acid-fast BCG-mycobacteria were found to be morphologically and functionally heterogeneous (in size, shape, and replication rates in colonies) in granuloma macrophages, dendritic cells, and multinucleate Langhans giant cells. Cord formation by BCG-mycobacteria in granuloma cells has been observed. Granuloma macrophages retained their ability to ingest damaged lymphocytes and thrombocytes in the phagosomes; however, their ability to destroy BCG-mycobacteria contained in these cells was compromised. No colocalization of BCG-mycobacteria and the LysoTracker dye was observed in the mouse cells. Various relationships between granuloma cells and BCG-mycobacteria were observed in different mice belonging to the same line. Several mice totally eliminated mycobacterial infection. Granulomas in the other mice had mycobacteria actively replicating in cells of different types and forming cords, which is an indicator of mycobacterial virulence and, probably, a marker of the activation of tuberculous infection in animals. PMID:26064970

  16. Transcriptional activation of bovine leukemia virus in blood cells from experimentally infected, asymptomatic sheep with latent infections.

    PubMed Central

    Lagarias, D M; Radke, K

    1989-01-01

    Infection by bovine leukemia virus (BLV) is characterized by a long latency period, after which some individuals develop B-cell tumors. The behavior of BLV and related retroviruses during the latency period between initial infection and subsequent tumorigenesis is poorly understood. We used in situ hybridization to detect BLV transcripts in individual peripheral blood mononuclear cells from experimentally infected, asymptomatic sheep with latent infections. Viral RNA was not found in most peripheral blood cells that had been isolated as rapidly as possible from circulating blood, but it was present in rare cells. BLV RNA transcripts increased in a biphasic manner within a few hours after the blood cells were placed in culture. Exposure to fetal bovine serum was identified as the principal cause of this transcriptional activation, which occurred in fewer than 1 in 1,000 cells. Agents known to activate immune cells polyclonally caused a further increase in the number of cells containing BLV RNA within 8 h. In some cases, the numbers of viral transcripts within individual cells also increased. Thus, BLV is not detectably expressed in most resting lymphocytes circulating in the blood, but its transcription is activated by components of fetal bovine serum and can be augmented by molecules that mimic activation of immune cells. This activation, which might occur in lymphoid tissue during an immune response, may lead to the synthesis of viral regulatory proteins that are thought to initiate tumorigenesis through host cell genes. Images PMID:2539506

  17. Anti-HIV Designer T Cells Progressively Eradicate a Latently Infected Cell Line by Sequentially Inducing HIV Reactivation then Killing the Newly Gp120-Positive Cells

    PubMed Central

    Sahu, Gautam K; Sango, Kaori; Selliah, Nithianandan; Ma, Qiangzhong; Skowron, Gail; Junghans, Richard P

    2013-01-01

    The current antiretroviral therapy (ART) can effectively reduce plasma HIV loads to undetectable levels, but cannot eliminate latently infected resting memory CD4 T cells that persist for the lifetime of infected patients. Therefore, designing new therapeutic approaches to eliminate these latently infected cells or the cells that produce HIV upon reactivation from latency is a priority in the ART era in order to progress to a cure of HIV. Here, we show that “designer” T cells expressing chimeric antigen receptor (CAR), CD4-CD28-CD3ζ, can target and kill HIV Env-expressing cells. Further, they secrete effector cytokines upon contact with HIV Env+ target cells that can reactivate latent HIV in a cell line model, thereby exposing those cells to recognition and killing by anti-HIV CAR+ T cells. Taken to the limit, this process could form the basis for an eventual functional or sterilizing cure for HIV in patients. PMID:24074590

  18. Analysis of human immunodeficiency virus-infected tissues by amplification and in situ hybridization reveals latent and permissive infections at single-cell resolution.

    PubMed Central

    Embretson, J; Zupancic, M; Beneke, J; Till, M; Wolinsky, S; Ribas, J L; Burke, A; Haase, A T

    1993-01-01

    Latent and productive viral infections are at the extremes of the spectrum of virus-cell interactions that are thought to play a major role in the ability of such important human pathogens as human immunodeficiency virus (HIV) to elude host defenses and cause disease. The recent development of PCR-based methods to amplify target sequences in individual cells in routinely fixed tissues affords opportunities to directly examine the subtle and covert virus-cell relationships at the latent end of the spectrum that are inaccessible to analysis by conventional in situ hybridization techniques. We have now used PCR in situ with in situ hybridization to document latent and permissive HIV infection in routinely fixed and paraffin-embedded tissue. In one of the first specimens we examined, a tumor biopsy from an HIV-infected individual, we found many of the lymphocytes and lymphocytes infiltrating the tumor had HIV DNA that was detectable only by PCR in situ. The fraction of positive cells varied regionally, but there were foci where most of the cells contained HIV DNA. Most of these lymphocytes and macrophages are latently infected, as we could detect HIV RNA in fewer than one in a thousand of these cells. We also detected HIV RNA, surprisingly, in 6% of the tumor cells, where the number of copies of viral RNA per cell was equivalent to productively infected cell lines. The alternative states of HIV-gene expression and high local concentration of latently infected lymphocytes and monocytes revealed by these studies conceptually supports models of lentiviral pathogenesis that attribute persistence to the reservoir of latently infected cells and disease to the consequences of viral-gene expression in this population. The magnitude of infection of lymphocytes documented in this report is also consistent with the emerging view that HIV infection per se could contribute substantially to depletion of immune cells in AIDS. Images PMID:8419941

  19. Stable Phenotypic Changes of the Host T Cells Are Essential to the Long-Term Stability of Latent HIV-1 Infection

    PubMed Central

    Seu, Lillian; Sabbaj, Steffanie; Duverger, Alexandra; Wagner, Frederic; Anderson, Joshua C.; Davies, Elizabeth; Wolschendorf, Frank; Willey, Christopher D.; Saag, Michael S.; Goepfert, Paul

    2015-01-01

    ABSTRACT The extreme stability of the latent HIV-1 reservoir in the CD4+ memory T cell population prevents viral eradication with current antiretroviral therapy. It has been demonstrated that homeostatic T cell proliferation and clonal expansion of latently infected T cells due to viral integration into specific genes contribute to this extraordinary reservoir stability. Nevertheless, given the constant exposure of the memory T cell population to specific antigen or bystander activation, this reservoir stability seems remarkable, unless it is assumed that latent HIV-1 resides exclusively in memory T cells that recognize rare antigens. Another explanation for the stability of the reservoir could be that the latent HIV-1 reservoir is associated with an unresponsive T cell phenotype. We demonstrate here that host cells of latent HIV-1 infection events were functionally altered in ways that are consistent with the idea of an anergic, unresponsive T cell phenotype. Manipulations that induced or mimicked an anergic T cell state promoted latent HIV-1 infection. Kinome analysis data reflected this altered host cell phenotype at a system-wide level and revealed how the stable kinase activity changes networked to stabilize latent HIV-1 infection. Protein-protein interaction networks generated from kinome data could further be used to guide targeted genetic or pharmacological manipulations that alter the stability of latent HIV-1 infection. In summary, our data demonstrate that stable changes to the signal transduction and transcription factor network of latently HIV-1 infected host cells are essential to the ability of HIV-1 to establish and maintain latent HIV-1 infection status. IMPORTANCE The extreme stability of the latent HIV-1 reservoir allows the infection to persist for the lifetime of a patient, despite completely suppressive antiretroviral therapy. This extreme reservoir stability is somewhat surprising, since the latently HIV-1 infected CD4+ memory T cells that

  20. Genome-wide analysis of T cell responses during acute and latent simian varicella virus infections in rhesus macaques.

    PubMed

    Haberthur, Kristen; Kraft, Aubrey; Arnold, Nicole; Park, Byung; Meyer, Christine; Asquith, Mark; Dewane, Jesse; Messaoudi, Ilhem

    2013-11-01

    Varicella zoster virus (VZV) is the etiological agent of varicella (chickenpox) and herpes zoster (HZ [shingles]). Clinical observations suggest that VZV-specific T cell immunity plays a more critical role than humoral immunity in the prevention of VZV reactivation and development of herpes zoster. Although numerous studies have characterized T cell responses directed against select VZV open reading frames (ORFs), a comprehensive analysis of the T cell response to the entire VZV genome has not yet been conducted. We have recently shown that intrabronchial inoculation of young rhesus macaques with simian varicella virus (SVV), a homolog of VZV, recapitulates the hallmarks of acute and latent VZV infection in humans. In this study, we characterized the specificity of T cell responses during acute and latent SVV infection. Animals generated a robust and broad T cell response directed against both structural and nonstructural viral proteins during acute infection in bronchoalveolar lavage (BAL) fluid and peripheral blood. During latency, T cell responses were detected only in the BAL fluid and were lower and more restricted than those observed during acute infection. Interestingly, we identified a small set of ORFs that were immunogenic during both acute and latent infection in the BAL fluid. Given the close genome relatedness of SVV and VZV, our studies highlight immunogenic ORFs that may be further investigated as potential components of novel VZV vaccines that specifically boost T cell immunity. PMID:23986583

  1. Dual-Affinity Re-Targeting proteins direct T cell–mediated cytolysis of latently HIV-infected cells

    PubMed Central

    Sung, Julia A.M.; Pickeral, Joy; Liu, Liqin; Stanfield-Oakley, Sherry A.; Lam, Chia-Ying Kao; Garrido, Carolina; Pollara, Justin; LaBranche, Celia; Bonsignori, Mattia; Moody, M. Anthony; Yang, Yinhua; Parks, Robert; Archin, Nancie; Allard, Brigitte; Kirchherr, Jennifer; Kuruc, JoAnn D.; Gay, Cynthia L.; Cohen, Myron S.; Ochsenbauer, Christina; Soderberg, Kelly; Liao, Hua-Xin; Montefiori, David; Moore, Paul; Johnson, Syd; Koenig, Scott; Haynes, Barton F.; Nordstrom, Jeffrey L.; Margolis, David M.; Ferrari, Guido

    2015-01-01

    Enhancement of HIV-specific immunity is likely required to eliminate latent HIV infection. Here, we have developed an immunotherapeutic modality aimed to improve T cell–mediated clearance of HIV-1–infected cells. Specifically, we employed Dual-Affinity Re-Targeting (DART) proteins, which are bispecific, antibody-based molecules that can bind 2 distinct cell-surface molecules simultaneously. We designed DARTs with a monovalent HIV-1 envelope-binding (Env-binding) arm that was derived from broadly binding, antibody-dependent cellular cytotoxicity–mediating antibodies known to bind to HIV-infected target cells coupled to a monovalent CD3 binding arm designed to engage cytolytic effector T cells (referred to as HIVxCD3 DARTs). Thus, these DARTs redirected polyclonal T cells to specifically engage with and kill Env-expressing cells, including CD4+ T cells infected with different HIV-1 subtypes, thereby obviating the requirement for HIV-specific immunity. Using lymphocytes from patients on suppressive antiretroviral therapy (ART), we demonstrated that DARTs mediate CD8+ T cell clearance of CD4+ T cells that are superinfected with the HIV-1 strain JR-CSF or infected with autologous reservoir viruses isolated from HIV-infected–patient resting CD4+ T cells. Moreover, DARTs mediated CD8+ T cell clearance of HIV from resting CD4+ T cell cultures following induction of latent virus expression. Combined with HIV latency reversing agents, HIVxCD3 DARTs have the potential to be effective immunotherapeutic agents to clear latent HIV-1 reservoirs in HIV-infected individuals. PMID:26413868

  2. Genome-wide analysis of histone modifications in latently HIV-1 infected T cells

    PubMed Central

    Park, Jihwan; Lim, Chae Hyun; Ham, Seokjin; Kim, Sung Soon; Choi, Byeong-Sun; Roh, Tae-Young

    2014-01-01

    Objectives: The transcriptional silencing of HIV type 1 (HIV-1) provirus in latently infected cells is a major hurdle on the pathway to HIV-1 elimination. The epigenetic mechanisms established by histone modifications may affect the transcriptional silencing of HIV-1 and viral latency. A systematic epigenome profiling could be applicable to develop new epigenetic diagnostic markers for detecting HIV-1 latency. Design: The HIV-1 latency cell lines (NCHA1, NCHA2 and ACH2] were compared with CD4+ T-cell line (A3.01). Methods: The histone modification profiles obtained from chromatin immunoprecipiation followed by sequencing (ChIP-Seq) for histone H3K4me3 and H3K9ac were systematically examined and differential gene expression patterns along with levels of histone modifications were used for network analysis. Results: The HIV-1 latency gave rise to downregulation of histone H3K4me3 and H3K9ac levels in 387 and 493 regions and upregulation in 451 and 962 sites, respectively. By network analysis, five gene clusters were associated with downregulated histone modifications and six gene clusters came up with upregulated histone modifications. Integration of gene expression with epigenetic information revealed that the cell cycle regulatory genes such as CDKN1A (p21) and cyclin D2 (CCND2) identified by differentially modified histones might play an important role in maintaining the HIV-1 latency. Conclusion: The transcriptional regulation by epigenetic memory should play a key role in the evolution and maintenance of HIV-1 latency accompanied by modulation of signalling molecules in the host cells. PMID:24762674

  3. The switch from latent to productive infection in epstein-barr virus-infected B cells is associated with sensitization to NK cell killing.

    PubMed

    Pappworth, Isabel Y; Wang, Eddie C; Rowe, Martin

    2007-01-01

    Following activation of Epstein-Barr virus (EBV)-infected B cells from latent to productive (lytic) infection, there is a concomitant reduction in the level of cell surface major histocompatibility complex (MHC) class I molecules and an impaired antigen-presenting function that may facilitate evasion from EBV-specific CD8+ cytotoxic T cells. In some other herpesviruses studied, most notably human cytomegalovirus (HCMV), evasion of virus-specific CD8+ effector responses via downregulation of surface MHC class I molecules is supplemented with specific mechanisms for evading NK cells. We now report that EBV differs from HCMV in this respect. While latently infected EBV-positive B cells were resistant to lysis by two NK lines and by primary polyclonal NK cells from peripheral blood, these effectors efficiently killed cells activated into the lytic cycle. Susceptibility to NK lysis coincided not only with downregulation of HLA-A, -B, and -C molecules that bind to the KIR family of inhibitory receptors on NK cells but also with downregulation of HLA-E molecules binding the CD94/NKG2A inhibitory receptors. Conversely, ULBP-1 and CD112, ligands for the NK cell-activating receptors NKG2D and DNAM-1, respectively, were elevated. Susceptibility of the virus-producing target cells to NK cell lysis was partially reversed by blocking ULBP-1 or CD112 with specific antibodies. These results highlight a fundamental difference between EBV and HCMV with regards to evasion of innate immunity. PMID:17079298

  4. Latent cytomegalovirus infection enhances anti-tumour cytotoxicity through accumulation of NKG2C+ NK cells in healthy humans.

    PubMed

    Bigley, A B; Rezvani, K; Shah, N; Sekine, T; Balneger, N; Pistillo, M; Agha, N; Kunz, H; O'Connor, D P; Bollard, C M; Simpson, R J

    2016-08-01

    Cytomegalovirus (CMV) infection markedly expands NKG2C+/NKG2A- NK cells, which are potent killers of infected cells expressing human leucocyte antigen (HLA)-E. As HLA-E is also over-expressed in several haematological malignancies and CMV has been linked to a reduced risk of leukaemic relapse, we determined the impact of latent CMV infection on NK cell cytotoxicity against four tumour target cell lines with varying levels of HLA-E expression. NK cell cytotoxicity against K562 (leukaemia origin) and U266 (multiple myeloma origin) target cells was strikingly greater in healthy CMV-seropositive donors than seronegative donors and was associated strongly with target cell HLA-E and NK cell NKG2C expression. NK cell cytotoxicity against HLA-E transfected lymphoma target cells (221.AEH) was ∼threefold higher with CMV, while NK cell cytotoxicity against non-transfected 721.221 cells was identical between the CMV groups. NK cell degranulation (CD107a(+) ) and interferon (IFN)-γ production to 221.AEH cells was localized almost exclusively to the NKG2C subset, and antibody blocking of NKG2C completely eliminated the effect of CMV on NK cell cytotoxicity against 221.AEH cells. Moreover, 221.AEH feeder cells and interleukin (IL)-15 were found to expand NKG2C(+) /NKG2A(-) NK cells preferentially from CMV-seronegative donors and increase NK cell cytotoxicity against HLA-E(+) tumour cell lines. We conclude that latent CMV infection enhances NK cell cytotoxicity through accumulation of NKG2C(+) NK cells, which may be beneficial in preventing the initiation and progression of haematological malignancies characterized by high HLA-E expression. PMID:26940026

  5. Differences between Mycobacterium-Host Cell Relationships in Latent Tuberculous Infection of Mice Ex Vivo and Mycobacterial Infection of Mouse Cells In Vitro

    PubMed Central

    Ufimtseva, Elena

    2016-01-01

    The search for factors that account for the reproduction and survival of mycobacteria, including vaccine strains, in host cells is the priority for studies on tuberculosis. A comparison of BCG-mycobacterial loads in granuloma cells obtained from bone marrow and spleens of mice with latent tuberculous infection and cells from mouse bone marrow and peritoneal macrophage cultures infected with the BCG vaccine in vitro has demonstrated that granuloma macrophages each normally contained a single BCG-Mycobacterium, while those acutely infected in vitro had increased mycobacterial loads and death rates. Mouse granuloma cells were observed to produce the IFNγ, IL-1α, GM-CSF, CD1d, CD25, CD31, СD35, and S100 proteins. None of these activation markers were found in mouse cell cultures infected in vitro or in intact macrophages. Lack of colocalization of lipoarabinomannan-labeled BCG-mycobacteria with the lysosomotropic LysoTracker dye in activated granuloma macrophages suggests that these macrophages were unable to destroy BCG-mycobacteria. However, activated mouse granuloma macrophages could control mycobacterial reproduction in cells both in vivo and in ex vivo culture. By contrast, a considerable increase in the number of BCG-mycobacteria was observed in mouse bone marrow and peritoneal macrophages after BCG infection in vitro, when no expression of the activation-related molecules was detected in these cells. PMID:27066505

  6. Modeling the Effects of Vorinostat In Vivo Reveals both Transient and Delayed HIV Transcriptional Activation and Minimal Killing of Latently Infected Cells

    PubMed Central

    Ke, Ruian; Lewin, Sharon R.; Elliott, Julian H; Perelson, Alan S.

    2015-01-01

    Recent efforts to cure human immunodeficiency virus type-1 (HIV-1) infection have focused on developing latency reversing agents as a first step to eradicate the latent reservoir. The histone deacetylase inhibitor, vorinostat, has been shown to activate HIV RNA transcription in CD4+ T-cells and alter host cell gene transcription in HIV-infected individuals on antiretroviral therapy. In order to understand how latently infected cells respond dynamically to vorinostat treatment and determine the impact of vorinostat on reservoir size in vivo, we have constructed viral dynamic models of latency that incorporate vorinostat treatment. We fitted these models to data collected from a recent clinical trial in which vorinostat was administered daily for 14 days to HIV-infected individuals on suppressive ART. The results show that HIV transcription is increased transiently during the first few hours or days of treatment and that there is a delay before a sustained increase of HIV transcription, whose duration varies among study participants and may depend on the long term impact of vorinostat on host gene expression. Parameter estimation suggests that in latently infected cells, HIV transcription induced by vorinostat occurs at lower levels than in productively infected cells. Furthermore, the estimated loss rate of transcriptionally induced cells remains close to baseline in most study participants, suggesting vorinostat treatment does not induce latently infected cell killing and thus reduce the latent reservoir in vivo. PMID:26496627

  7. Modeling the effects of vorinostat in vivo reveals both transient and delayed HIV transcriptional activation and minimal killing of latently infected cells

    SciTech Connect

    Ke, Ruian; Lewin, Sharon R.; Elliott, Julian H.; Perelson, Alan S.; Chakraborty, Arup K.

    2015-10-23

    Recent efforts to cure human immunodeficiency virus type-1 (HIV-1) infection have focused on developing latency reversing agents as a first step to eradicate the latent reservoir. The histone deacetylase inhibitor, vorinostat, has been shown to activate HIV RNA transcription in CD4+ T-cells and alter host cell gene transcription in HIV-infected individuals on antiretroviral therapy. In order to understand how latently infected cells respond dynamically to vorinostat treatment and determine the impact of vorinostat on reservoir size in vivo, we have constructed viral dynamic models of latency that incorporate vorinostat treatment. We fitted these models to data collected from a recent clinical trial in which vorinostat was administered daily for 14 days to HIV-infected individuals on suppressive ART. The results show that HIV transcription is increased transiently during the first few hours or days of treatment and that there is a delay before a sustained increase of HIV transcription, whose duration varies among study participants and may depend on the long term impact of vorinostat on host gene expression. Parameter estimation suggests that in latently infected cells, HIV transcription induced by vorinostat occurs at lower levels than in productively infected cells. Lastly, the estimated loss rate of transcriptionally induced cells remains close to baseline in most study participants, suggesting vorinostat treatment does not induce latently infected cell killing and thus reduce the latent reservoir in vivo.

  8. Modeling the Effects of Vorinostat In Vivo Reveals both Transient and Delayed HIV Transcriptional Activation and Minimal Killing of Latently Infected Cells.

    PubMed

    Ke, Ruian; Lewin, Sharon R; Elliott, Julian H; Perelson, Alan S

    2015-10-01

    Recent efforts to cure human immunodeficiency virus type-1 (HIV-1) infection have focused on developing latency reversing agents as a first step to eradicate the latent reservoir. The histone deacetylase inhibitor, vorinostat, has been shown to activate HIV RNA transcription in CD4+ T-cells and alter host cell gene transcription in HIV-infected individuals on antiretroviral therapy. In order to understand how latently infected cells respond dynamically to vorinostat treatment and determine the impact of vorinostat on reservoir size in vivo, we have constructed viral dynamic models of latency that incorporate vorinostat treatment. We fitted these models to data collected from a recent clinical trial in which vorinostat was administered daily for 14 days to HIV-infected individuals on suppressive ART. The results show that HIV transcription is increased transiently during the first few hours or days of treatment and that there is a delay before a sustained increase of HIV transcription, whose duration varies among study participants and may depend on the long term impact of vorinostat on host gene expression. Parameter estimation suggests that in latently infected cells, HIV transcription induced by vorinostat occurs at lower levels than in productively infected cells. Furthermore, the estimated loss rate of transcriptionally induced cells remains close to baseline in most study participants, suggesting vorinostat treatment does not induce latently infected cell killing and thus reduce the latent reservoir in vivo. PMID:26496627

  9. Modeling the effects of vorinostat in vivo reveals both transient and delayed HIV transcriptional activation and minimal killing of latently infected cells

    DOE PAGESBeta

    Ke, Ruian; Lewin, Sharon R.; Elliott, Julian H.; Perelson, Alan S.; Chakraborty, Arup K.

    2015-10-23

    Recent efforts to cure human immunodeficiency virus type-1 (HIV-1) infection have focused on developing latency reversing agents as a first step to eradicate the latent reservoir. The histone deacetylase inhibitor, vorinostat, has been shown to activate HIV RNA transcription in CD4+ T-cells and alter host cell gene transcription in HIV-infected individuals on antiretroviral therapy. In order to understand how latently infected cells respond dynamically to vorinostat treatment and determine the impact of vorinostat on reservoir size in vivo, we have constructed viral dynamic models of latency that incorporate vorinostat treatment. We fitted these models to data collected from a recentmore » clinical trial in which vorinostat was administered daily for 14 days to HIV-infected individuals on suppressive ART. The results show that HIV transcription is increased transiently during the first few hours or days of treatment and that there is a delay before a sustained increase of HIV transcription, whose duration varies among study participants and may depend on the long term impact of vorinostat on host gene expression. Parameter estimation suggests that in latently infected cells, HIV transcription induced by vorinostat occurs at lower levels than in productively infected cells. Lastly, the estimated loss rate of transcriptionally induced cells remains close to baseline in most study participants, suggesting vorinostat treatment does not induce latently infected cell killing and thus reduce the latent reservoir in vivo.« less

  10. A Novel Histone Deacetylase Inhibitor, AR-42, Reactivates HIV-1 from Chronically and Latently Infected CD4+ T-cells

    PubMed Central

    Mates, Jessica M.; de Silva, Suresh; Lustberg, Mark; Van Deusen, Kelsey; Baiocchi, Robert A.; Wu, Li; Kwiek, Jesse J.

    2015-01-01

    Human immunodeficiency virus type 1 (HIV-1) latency is a major barrier to a cure of AIDS. Latently infected cells harbor an integrated HIV-1 genome but are not actively producing HIV-1. Histone deacetylase (HDAC) inhibitors, such as vorinostat (SAHA), have been shown to reactivate latent HIV-1. AR-42, a modified HDAC inhibitor, has demonstrated efficacy against malignant melanoma, meningioma, and acute myeloid leukemia and is currently used in clinical trials for non-Hodgkin’s lymphoma and multiple myeloma. In this study, we evaluated the ability of AR-42 to reactivate HIV-1 in the two established CD4+ T-cell line models of HIV-1 latency. In HIV-1 chronically infected ACH-2 cells, AR-42-induced histone acetylation was more potent and robust than that of vorinostat. Although AR-42 and vorinostat were equipotent in their ability to reactivate HIV-1, AR-42-induced maximal HIV-1 reactivation was twofold greater than vorinostat in ACH-2 and J-Lat (clone 9.2) cells. These data provide rationale for assessing the efficacy of AR-42-mediated HIV-1 reactivation within primary CD4+ T-cells. PMID:26855567

  11. Circulating herpes simplex type 1 (HSV-1)-specific CD8+ T cells do not access HSV-1 latently infected trigeminal ganglia

    PubMed Central

    2011-01-01

    Background Therapeutic vaccines can be designed to enhance existing T cell memory populations for increased protection against re-infection. In the case of herpes simplex virus type 1, recurrent disease results from reactivation of latent virus in sensory ganglia, which is controlled in part by a ganglia-resident HSV-specific memory CD8+ T cell population. Thus, an important goal of a therapeutic HSV-1 vaccine would be to enhance this population. Methods HSV-1-infected mice were treated with TAK-779 to block CCR5- and CXCR3-mediated CD8+ T cell migration during both acute and latent infections. Additionally, HSV-1-specific CD8+ T cells were transferred into HSV-1 latently infected mice to mimic the effect of a therapeutic vaccine, and their migration into trigeminal ganglia (TG) was traced during steady-state latency, or during recovery of the TG-resident memory CD8+ T cell population following stress-, and corticosterone-induced depletion and HSV-1 reactivation from latency. Bromodeoxy uridine (BrdU) incorporation measured cell proliferation in vivo. Results TAK-779 treatment during acute HSV-1 infection reduced the number of infiltrating CD8+ T cells but did not alter the number of viral genome copies. TAK-779 treatment during HSV latency did not affect the size of the TG-resident memory CD8+ T cell population. Transferred HSV-specific CD8+ T cells failed to access latently infected TG during steady-state latency, or during recovery of the TG resident HSV-specific CD8+ T cell population following exposure of latently infected mice to stress and corticosterone. Recovery of the HSV-specific CD8+ T cell population after stress and corticosterone treatment occurred with homeostatic levels of cell division and did not require CD4+ T cell help. Conclusions Our findings are consistent with the notion that the CD8+ T cells in latently infected TG are a tissue-resident memory (Trm) population that is maintained without replenishment from the periphery, and that when this

  12. Treatment of latent tuberculosis infection induces changes in multifunctional Mycobacterium tuberculosis-specific CD4+ T cells.

    PubMed

    Sauzullo, Ilaria; Mengoni, Fabio; Mascia, Claudia; Rossi, Raffaella; Lichtner, Miriam; Vullo, Vincenzo; Mastroianni, Claudio M

    2016-02-01

    To ascertain whether multiparametric flow cytometry assessment of multifunctional Mycobacterium tuberculosis (Mtb)-specific CD4(+) and CD8(+) T cells can distinguish between untreated and treated patients with latent tuberculosis infection (LTBI), we enrolled 14 LTBI subjects treated with isoniazid (INH) therapy, 16 untreated LTBI patients, and 25 healthy controls. The analysis of mono-functional CD4(+) and CD8(+) T cells producing single cytokines showed significant differences only between uninfected and infected LTBI subjects (both treated and untreated). Conversely, the analysis of multifunctional CD4(+) T cells revealed a significant reduction in the frequency of two CD4(+) T cells subsets, those producing IFN-γ, IL-2, and TNF-α simultaneously (triple positive; p = 0.005) and those producing IL-2 alone (p = 0.0359), as well as a shift towards T cells producing only one cytokine in treated as compared to untreated LTBI subjects. Assigning a triple-positive CD4(+) T cells a cut-off >0.082 %, 94 % of untreated LTBI patients were scored as positive, as compared to only 28 % of treated LTBI patients and none of the healthy controls. No significant differences between untreated and treated LTBI subjects in terms of Mtb-specific CD8(+) T cell cytokine profiles (p > 0.05) were identified. The significant changes in the cytokine profiles of Mtb-specific T cells after INH therapy suggest that analysis of multifunctional T cells may be a promising means for the monitoring of LTBI treatment success. PMID:26108901

  13. Limited but durable changes to cellular gene expression in a model of latent adenovirus infection are reflected in childhood leukemic cell lines.

    PubMed

    Ornelles, D A; Gooding, L R; Dickherber, M L; Policard, M; Garnett-Benson, C

    2016-07-01

    Mucosal lymphocytes support latent infections of species C adenoviruses. Because infected lymphocytes resist re-infection with adenovirus, we sought to identify changes in cellular gene expression that could inhibit the infectious process. The expression of over 30,000 genes was evaluated by microarray in persistently infected B-and T-lymphocytic cells. BBS9, BNIP3, BTG3, CXADR, SLFN11 and SPARCL1 were the only genes differentially expressed between mock and infected B cells. Most of these genes are associated with oncogenesis or cancer progression. Histone deacetylase and DNA methyltransferase inhibitors released the repression of some of these genes. Cellular and viral gene expression was compared among leukemic cell lines following adenovirus infection. Childhood leukemic B-cell lines resist adenovirus infection and also show reduced expression of CXADR and SPARCL. Thus adenovirus induces limited changes to infected B-cell lines that are similar to changes observed in childhood leukemic cell lines. PMID:27085068

  14. Limited but durable changes to cellular gene expression in a model of latent adenovirus infection are reflected in childhood leukemic cell lines

    PubMed Central

    Ornelles, D.A.; Gooding, L.R.; Dickherber, M.L.; Policard, M.; Garnett-Benson, C.

    2016-01-01

    Mucosal lymphocytes support latent infections of species C adenoviruses. Because infected lymphocytes resist re-infection with adenovirus, we sought to identify changes in cellular gene expression that could inhibit the infectious process. The expression of over 30,000 genes was evaluated by microarray in persistently infected B-and T-lymphocytic cells. BBS9, BNIP3, BTG3, CXADR, SLFN11 and SPARCL1 were the only genes differentially expressed between mock and infected B cells. Most of these genes are associated with oncogenesis or cancer progression. Histone deacetylase and DNA methyltransferase inhibitors released the repression of some of these genes. Cellular and viral gene expression was compared among leukemic cell lines following adenovirus infection. Childhood leukemic B-cell lines resist adenovirus infection and also show reduced expression of CXADR and SPARCL. Thus adenovirus induces limited changes to infected B-cell lines that are similar to changes observed in childhood leukemic cell lines. PMID:27085068

  15. Optimization of chemical induction conditions for human herpesvirus 8 (HHV-8) reactivation with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) from latently-infected BC-3 cells.

    PubMed

    Ma, Wenbin; Galvin, Teresa A; Ma, Hailun; Ma, Yunkun; Muller, Jacqueline; Khan, Arifa S

    2011-05-01

    Human herpesvirus 8 (HHV-8) persists as episomal DNA in latently-infected cells and can establish two alternative life cycles, latent or lytic. 12-O-tetradecanoyl-phorbol-13-acetate (TPA) is a known inducer of HHV-8 in several human primary effusion lymphoma cell lines and has been widely used for HHV-8 reactivation; however, induction conditions have differed, resulting in varying levels of virus expression. We have used HHV-8 latently-infected BC-3 cells as a model to determine critical parameters for optimizing virus reactivation by TPA. We found that cell growth properties and drug treatment conditions were important for maximum reactivation of HHV-8. Addition of TPA to cells in the early log phase of a sigmoidal growth curve, which was tightly associated with high percentage of the cells in early S phase and with lower histone deacetylase activity in the cells, provided the optimum cell conditions for latent virus to switch to lytic replication. Furthermore, increasing TPA concentration (up to 320 ng per ml) at 48 h exposure time resulted in increased virus production. The results demonstrate the use of a step-wise strategy with chemical induction that may facilitate broad detection of latent DNA viruses and novel virus discovery. PMID:21470875

  16. Cis and Trans Acting Factors Involved in Human Cytomegalovirus Experimental and Natural Latent Infection of CD14 (+) Monocytes and CD34 (+) Cells

    PubMed Central

    Pari, Gregory S.

    2013-01-01

    The parameters involved in human cytomegalovirus (HCMV) latent infection in CD14 (+) and CD34 (+) cells remain poorly identified. Using next generation sequencing we deduced the transcriptome of HCMV latently infected CD14 (+) and CD34 (+) cells in experimental as well as natural latency settings. The gene expression profile from natural infection in HCMV seropositive donors closely matched experimental latency models, and included two long non-coding RNAs (lncRNAs), RNA4.9 and RNA2.7 as well as the mRNAs encoding replication factors UL84 and UL44. Chromatin immunoprecipitation assays on experimentally infected CD14 (+) monocytes followed by next generation sequencing (ChIP-Seq) were employed to demonstrate both UL84 and UL44 proteins interacted with the latent viral genome and overlapped at 5 of the 8 loci identified. RNA4.9 interacts with components of the polycomb repression complex (PRC) as well as with the MIE promoter region where the enrichment of the repressive H3K27me3 mark suggests that this lncRNA represses transcription. Formaldehyde Assisted Isolation of Regulatory Elements (FAIRE), which identifies nucleosome-depleted viral DNA, was used to confirm that latent mRNAs were associated with actively transcribed, FAIRE analysis also showed that the terminal repeat (TR) region of the latent viral genome is depleted of nucleosomes suggesting that this region may contain an element mediating viral genome maintenance. ChIP assays show that the viral TR region interacts with factors associated with the pre replication complex and a plasmid subclone containing the HCMV TR element persisted in latently infected CD14 (+) monocytes, strongly suggesting that the TR region mediates viral chromosome maintenance. PMID:23717203

  17. Zebularine reactivates silenced E-cadherin but unlike 5-Azacytidine does not induce switching from latent to lytic Epstein-Barr virus infection in Burkitt's lymphoma Akata cells

    PubMed Central

    Rao, Sieta P; Rechsteiner, Markus P; Berger, Christoph; Sigrist, Jürg A; Nadal, David; Bernasconi, Michele

    2007-01-01

    Epigenetic silencing of regulatory genes by aberrant methylation contributes to tumorigenesis. DNA methyltransferase inhibitors (DNMTI) represent promising new drugs for anti-cancer therapies. The DNMTI 5-Azacytidine is effective against myelodysplastic syndrome, but induces switching of latent to lytic Epstein-Barr virus (EBV) in vitro and results in EBV DNA demethylation with the potential of induction of lytic EBV in vivo. This is of considerable concern given that recurrent lytic EBV has been linked with an increased incidence of EBV-associated lymphomas. Based on the distinct properties of action we hypothesized that the newer DNMTI Zebularine might differ from 5-Azacytidine in its potential to induce switching from latent to lytic EBV. Here we show that both 5-Azacytidine and Zebularine are able to induce expression of E-cadherin, a cellular gene frequently silenced by hypermethylation in cancers, and thus demonstrate that both DNMTI are active in our experimental setting consisting of EBV-harboring Burkitt's lymphoma Akata cells. Quantification of mRNA expression of EBV genes revealed that 5-Azacytidine induces switching from latent to lytic EBV and, in addition, that the immediate-early lytic infection progresses to early and late lytic infection. Furthermore, 5-Azacytidine induced upregulation of the latent EBV genes LMP2A, LMP2B, and EBNA2 in a similar fashion as observed following switching of latent to lytic EBV upon cross-linking of the B-cell receptor. In striking contrast, Zebularine did not exhibit any effect neither on lytic nor on latent EBV gene expression. Thus, Zebularine might be safer than 5-Azacytidine for the treatment of cancers in EBV carriers and could also be applied against EBV-harboring tumors, since it does not induce switching from latent to lytic EBV which may result in secondary EBV-associated malignancies. PMID:17214905

  18. Human peripheral blood and bone marrow Epstein-Barr virus-specific T-cell repertoire in latent infection reveals distinct memory T-cell subsets.

    PubMed

    Guerreiro, Manuel; Na, Il-Kang; Letsch, Anne; Haase, Doreen; Bauer, Sandra; Meisel, Christian; Roemhild, Andy; Reinke, Petra; Volk, Hans-Dieter; Scheibenbogen, Carmen

    2010-06-01

    EBV infection leads to life-long viral persistence. Although EBV infection can result in chronic disease and malignant transformation, most carriers remain disease-free as a result of effective control by T cells. EBV-specific IFN-gamma-producing T cells could be demonstrated in acute and chronic infection as well as during latency. Recent studies, however, provide evidence that assessing IFN-gamma alone is insufficient to assess the quantity and quality of a T-cell response. Using overlapping peptide pools of latent EBV nuclear antigen 1 and lytic BZLF-1 protein and multicolor flow cytometry, we demonstrate that the majority of ex vivo EBV-reactive T cells in healthy virus carriers are indeed IL-2- and/or TNF-producing memory cells, the latter being significantly more frequent in BM. After in vitro expansion, a substantial number of EBV-specific CD4(+) and CD8(+) T cells retained a CC-chemokine receptor 7 (CCR7)-positive memory phenotype. Based on their cytokine profiles, six different EBV-specific T-cell subsets could be distinguished with TNF-single or TNF/IL-2-double producing cells expressing the highest CCR7 levels resembling early-differentiated memory T cells. Our study delineates the memory T-cell profile of a protective immune response and provides a basis for analyzing T-cell responses in EBV-associated diseases. PMID:20232341

  19. Tuning of AKT-pathway by Nef and its blockade by protease inhibitors results in limited recovery in latently HIV infected T-cell line

    PubMed Central

    Kumar, Amit; Abbas, Wasim; Colin, Laurence; Khan, Kashif Aziz; Bouchat, Sophie; Varin, Audrey; Larbi, Anis; Gatot, Jean-Stéphane; Kabeya, Kabamba; Vanhulle, Caroline; Delacourt, Nadège; Pasquereau, Sébastien; Coquard, Laurie; Borch, Alexandra; König, Renate; Clumeck, Nathan; De Wit, Stephane; Rohr, Olivier; Rouzioux, Christine; Fulop, Tamas; Van Lint, Carine; Herbein, Georges

    2016-01-01

    Akt signaling plays a central role in many biological processes, which are key players in human immunodeficiency virus 1 (HIV-1) pathogenesis. We found that Akt interacts with HIV-1 Nef protein. In primary T cells treated with exogenous Nef or acutely infected with Nef-expressing HIV-1 in vitro, Akt became phosphorylated on serine473 and threonine308. In vitro, Akt activation mediated by Nef in T-cells was blocked by HIV protease inhibitors (PI), but not by reverse transcriptase inhibitors (RTI). Ex vivo, we found that the Akt pathway is hyperactivated in peripheral blood lymphocytes (PBLs) from cART naïve HIV-1-infected patients. PBLs isolated from PI-treated patients, but not from RTI-treated patients, exhibited decreased Akt activation, T-cell proliferation and IL-2 production. We found that PI but not RTI can block HIV-1 reactivation in latently infected J-Lat lymphoid cells stimulated with various stimuli. Using luciferase measurement, we further confirmed that Nef-mediated reactivation of HIV-1 from latency in 1G5 cells was blocked by PI parallel to decreased Akt activation. Our results indicate that PI-mediated blockade of Akt activation could impact the HIV-1 reservoir and support the need to further assess the therapeutic use of HIV-1 PI in order to curtail latently infected cells in HIV-1-infected patients. PMID:27076174

  20. Tuning of AKT-pathway by Nef and its blockade by protease inhibitors results in limited recovery in latently HIV infected T-cell line.

    PubMed

    Kumar, Amit; Abbas, Wasim; Colin, Laurence; Khan, Kashif Aziz; Bouchat, Sophie; Varin, Audrey; Larbi, Anis; Gatot, Jean-Stéphane; Kabeya, Kabamba; Vanhulle, Caroline; Delacourt, Nadège; Pasquereau, Sébastien; Coquard, Laurie; Borch, Alexandra; König, Renate; Clumeck, Nathan; De Wit, Stephane; Rohr, Olivier; Rouzioux, Christine; Fulop, Tamas; Van Lint, Carine; Herbein, Georges

    2016-01-01

    Akt signaling plays a central role in many biological processes, which are key players in human immunodeficiency virus 1 (HIV-1) pathogenesis. We found that Akt interacts with HIV-1 Nef protein. In primary T cells treated with exogenous Nef or acutely infected with Nef-expressing HIV-1 in vitro, Akt became phosphorylated on serine(473) and threonine(308). In vitro, Akt activation mediated by Nef in T-cells was blocked by HIV protease inhibitors (PI), but not by reverse transcriptase inhibitors (RTI). Ex vivo, we found that the Akt pathway is hyperactivated in peripheral blood lymphocytes (PBLs) from cART naïve HIV-1-infected patients. PBLs isolated from PI-treated patients, but not from RTI-treated patients, exhibited decreased Akt activation, T-cell proliferation and IL-2 production. We found that PI but not RTI can block HIV-1 reactivation in latently infected J-Lat lymphoid cells stimulated with various stimuli. Using luciferase measurement, we further confirmed that Nef-mediated reactivation of HIV-1 from latency in 1G5 cells was blocked by PI parallel to decreased Akt activation. Our results indicate that PI-mediated blockade of Akt activation could impact the HIV-1 reservoir and support the need to further assess the therapeutic use of HIV-1 PI in order to curtail latently infected cells in HIV-1-infected patients. PMID:27076174

  1. Detection of Epstein-Barr virus genome and latent infection gene expression in normal epithelia, epithelial dysplasia, and squamous cell carcinoma of the oral cavity.

    PubMed

    Kikuchi, Kentaro; Noguchi, Yoshihiro; de Rivera, Michelle Wendoline Garcia-Niño; Hoshino, Miyako; Sakashita, Hideaki; Yamada, Tsutomu; Inoue, Harumi; Miyazaki, Yuji; Nozaki, Tadashige; González-López, Blanca Silvia; Ide, Fumio; Kusama, Kaoru

    2016-03-01

    A relationship between Epstein-Barr virus (EBV) infection and cancer of lymphoid and epithelial tissues such as Burkitt's lymphoma, Hodgkin's disease, nasopharyngeal carcinoma (NPC), gastric carcinoma, and oral cancer has been reported. EBV is transmitted orally and infects B cells and epithelial cells. However, it has remained uncertain whether EBV plays a role in carcinogenesis of oral mucosal tissue. In the present study, we detected the EBV genome and latent EBV gene expression in normal mucosal epithelia, epithelial dysplasia, and oral squamous cell carcinoma (OSCC) to clarify whether EBV is involved in carcinogenesis of the oral cavity. We examined 333 formalin-fixed, paraffin-embedded tissue samples (morphologically normal oral mucosa 30 samples, gingivitis 32, tonsillitis 17, oral epithelial dysplasia 83, OSCC 150, and NPC 21). EBV latent infection genes (EBNA-2, LMP-1) were detected not only in OSCC (50.2 %, 10.7 %) but also in severe epithelial dysplasia (66.7 %, 44.4 %), mild to moderate epithelial dysplasia (43.1 %, 18.5 %), gingivitis (78.1 %, 21.9 %), and normal mucosa (83.3 %, 23.3 %). Furthermore, the intensity of EBV latent infection gene expression (EBER, LMP-1) was significantly higher in severe epithelial dysplasia (94.4 %, 72.2 %) than in OSCC (34.7 %, 38.7 %). These results suggest that EBV latent infection genes and their increased expression in severe epithelial dysplasia might play an important role in the dysplasia-carcinoma sequence in the oral cavity. PMID:26449822

  2. Kaposi's Sarcoma-Associated Herpesvirus Induces Nrf2 Activation in Latently Infected Endothelial Cells through SQSTM1 Phosphorylation and Interaction with Polyubiquitinated Keap1

    PubMed Central

    Gjyshi, Olsi; Flaherty, Stephanie; Veettil, Mohanan Valiya; Johnson, Karen E.; Chandran, Bala

    2014-01-01

    ABSTRACT Nuclear factor erythroid 2-related factor 2 (Nrf2), the cellular master regulator of the antioxidant response, dissociates from its inhibitor Keap1 when activated by stress signals and participates in the pathogenesis of viral infections and tumorigenesis. Early during de novo infection of endothelial cells, KSHV induces Nrf2 through an intricate mechanism involving reactive oxygen species (ROS) and prostaglandin E2 (PGE2). When we investigated the Nrf2 activity during latent KSHV infection, we observed increased nuclear serine-40-phosphorylated Nrf2 in human KS lesions compared to that in healthy tissues. Using KSHV long-term-infected endothelial cells (LTC) as a cellular model for KS, we demonstrated that KSHV infection induces Nrf2 constitutively by extending its half-life, increasing its phosphorylation by protein kinase Cζ (PKCζ) via the infection-induced cyclooxygenase-2 (COX-2)/PGE2 axis and inducing its nuclear localization. Nrf2 knockdown in LTC decreased expression of antioxidant genes and genes involved in KS pathogenesis such as the NAD(P)H quinone oxidase 1 (NQO1), gamma glutamylcysteine synthase heavy unit (γGCSH), the cysteine transporter (xCT), interleukin 6 (IL-6), and vascular endothelial growth factor A (VEGF-A) genes. Nrf2 activation was independent of oxidative stress but dependent on the autophagic protein sequestosome-1 (SQSTM1; p62). SQSTM1 levels were elevated in LTC, a consequence of protein accumulation due to decreased autophagy and Nrf2-mediated transcriptional activation. SQSTM1 was phosphorylated on serine-351 and -403, while Keap1 was polyubiquitinated with lysine-63–ubiquitin chains, modifications known to increase their mutual affinity and interaction, leading to Keap1 degradation and Nrf2 activation. The latent KSHV protein Fas-associated death domain-like interleukin-1β-converting enzyme-inhibitory protein (vFLIP) increased SQSTM1 expression and activated Nrf2. Collectively, these results demonstrate that KSHV

  3. Tuberculin skin test and interferon-gamma release assay values are associated with antimicrobial peptides expression in  polymorphonuclear cells during latent tuberculous infection.

    PubMed

    Castañeda-Delgado, Julio E; Cervantes-Villagrana, Alberto; Serrano-Escobedo, Carmen J; Frausto-Lujan, Isabel; Rivas-Santiago, Cesar; Enciso-Moreno, Jose A; Rivas-Santiago, Bruno

    2014-06-01

    It has been reported that patients with progressive tuberculosis (TB) express abundant amounts of the antimicrobial peptides (AMPs) cathelicidin (LL-37) and human neutrophil peptide-1 (HNP-1) in circulating cells, whereas latent TB infected donors showed no differences when compared with purified protein derivative (PPD) and QuantiFERON®-TB Gold (QFT)-healthy individuals. The aim of this study was to determine whether LL-37 and HNP-1 production correlates with higher tuberculin skin test (TST) and QFT values in TB household contacts. Twenty-six TB household contact individuals between 26-58 years old TST and QFT positive with at last two years of latent TB infection were recruited. AMPs production by polymorphonuclear cells was determined by flow cytometry and correlation between TST and QFT values was analysed. Our results showed that there is a positive correlation between levels of HNP-1 and LL-37 production with reactivity to TST and/or QFT levels. This preliminary study suggests the potential use of the expression levels of these peptides as biomarkers for progression in latent infected individuals. PMID:24937049

  4. Tuberculin skin test and interferon-gamma release assay values are associated with antimicrobial peptides expression in  polymorphonuclear cells during latent tuberculous infection

    PubMed Central

    Castañeda-Delgado, Julio E; Cervantes-Villagrana, Alberto; Serrano-Escobedo, Carmen J; Frausto-Lujan, Isabel; Rivas-Santiago, Cesar; Enciso-Moreno, Jose A; Rivas-Santiago, Bruno

    2014-01-01

    It has been reported that patients with progressive tuberculosis (TB) express abundant amounts of the antimicrobial peptides (AMPs) cathelicidin (LL-37) and human neutrophil peptide-1 (HNP-1) in circulating cells, whereas latent TB infected donors showed no differences when compared with purified protein derivative (PPD) and QuantiFERON®-TB Gold (QFT)-healthy individuals. The aim of this study was to determine whether LL-37 and HNP-1 production correlates with higher tuberculin skin test (TST) and QFT values in TB household contacts. Twenty-six TB household contact individuals between 26-58 years old TST and QFT positive with at last two years of latent TB infection were recruited. AMPs production by polymorphonuclear cells was determined by flow cytometry and correlation between TST and QFT values was analysed. Our results showed that there is a positive correlation between levels of HNP-1 and LL-37 production with reactivity to TST and/or QFT levels. This preliminary study suggests the potential use of the expression levels of these peptides as biomarkers for progression in latent infected individuals. PMID:24937049

  5. Latent infection of myeloid progenitors by human cytomegalovirus protects cells from FAS-mediated apoptosis through the cellular IL-10/PEA-15 pathway

    PubMed Central

    Lau, Jonathan C. H.; Sinclair, John

    2015-01-01

    Latent infection of primary CD34+ progenitor cells by human cytomegalovirus (HCMV) results in their increased survival in the face of pro-apoptotic signals. For instance, we have shown previously that primary myeloid cells are refractory to FAS-mediated killing and that cellular IL-10 (cIL-10) is an important survival factor for this effect. However, how cIL-10 mediates this protection is unclear. Here, we have shown that cIL-10 signalling leading to upregulation of the cellular factor PEA-15 mediates latency-associated protection of CD34+ progenitor cells from the extrinsic death pathway. PMID:25957098

  6. The effects of age and latent cytomegalovirus infection on the redeployment of CD8+ T cell subsets in response to acute exercise in humans.

    PubMed

    Spielmann, Guillaume; Bollard, Catherine M; Bigley, Austin B; Hanley, Patrick J; Blaney, James W; LaVoy, Emily C P; Pircher, Hanspeter; Simpson, Richard J

    2014-07-01

    Dynamic exercise evokes a rapid redeployment of cytotoxic T cell subsets with high expression of β2 adrenergic receptors, presumably to enhance immunosurveillance during acute stress. As this response is affected by age and infection history, this study examined latent CMV infection as a potential confounder to age-related differences in blood CD8+ T-cell responses to exercise. Healthy young (n=16) and older (n=16) humans counterbalanced by CMV IgG serostatus (positive or negative) exercised for 30-min at ∼80% peak cycling power. Those with CMV redeployed ∼2-times more CD8+ T-cells and ∼6-times more KLRG1+/CD28- and CD45RA+/CCR7- CD8+ subsets than non-infected exercisers. Seronegative older exercisers had an impaired redeployment of total CD8+ T-cells, CD45RA+/CCR7+ and KLRG1-/CD28+ CD8+ subsets compared to young. Redeployed CD8+ T-cell numbers were similar between infected young and old. CMVpp65 specific CD8+ cells in HLA/A2(∗) subjects increased ∼2.7-fold after exercise, a response that was driven by the KLRG1+/CD28-/CD8+ subset. Stimulating PBMCs before and after exercise with CMVpp65 and CMV IE-1 antigens and overlapping peptide pools revealed a 2.1 and 4.4-fold increases in CMVpp65 and CMV IE-1 IFN-γ secreting cells respectively. The breadth of the T cell response was maintained after exercise with the magnitude of the response being amplified across the entire epitope repertoire. To conclude, latent CMV infection overrides age-related impairments in CD8+ T-cell redeployment with exercise. We also show for the first time that many T-cells redeployed with exercise are specific to CMVpp65 and CMV IE-1 antigens, have broad epitope specificity, and are mostly of a high-differentiated effector memory phenotype. PMID:23684819

  7. Glucocorticosteroids trigger reactivation of human cytomegalovirus from latently infected myeloid cells and increase the risk for HCMV infection in D+R+ liver transplant patients

    PubMed Central

    Van Damme, Ellen; Sauviller, Sarah; Lau, Betty; Kesteleyn, Bart; Griffiths, Paul; Burroughs, Andrew; Emery, Vincent; Sinclair, John

    2015-01-01

    Graft rejection in transplant patients is managed clinically by suppressing T-cell function with immunosuppressive drugs such as prednisolone and methylprednisolone. In such immunocompromised hosts, human cytomegalovirus (HCMV) is an important opportunistic pathogen and can cause severe morbidity and mortality. Currently, the effect of glucocorticosteroids (GCSs) on the HCMV life cycle remains unclear. Previous reports showed enhanced lytic replication of HCMV in vitro in the presence of GCSs. In the present study, we explored the implications of steroid exposure on latency and reactivation. We observed a direct effect of several GCSs used in the clinic on the activation of a quiescent viral major immediate-early promoter in stably transfected THP-1 monocytic cells. This activation was prevented by the glucocorticoid receptor (GR) antagonist Ru486 and by shRNA-mediated knockdown of the GR. Consistent with this observation, prednisolone treatment of latently infected primary monocytes resulted in HCMV reactivation. Analysis of the phenotype of these cells showed that treatment with GCSs was correlated with differentiation to an anti-inflammatory macrophage-like cell type. On the basis that these observations may be pertinent to HCMV reactivation in post-transplant settings, we retrospectively evaluated the incidence, viral kinetics and viral load of HCMV in liver transplant patients in the presence or absence of GCS treatment. We observed that combination therapy of baseline prednisolone and augmented methylprednisolone, upon organ rejection, significantly increased the incidence of HCMV infection in the intermediate risk group where donor and recipient are both HCMV seropositive (D+R+) to levels comparable with the high risk D+R− group. PMID:25312585

  8. Glucocorticosteroids trigger reactivation of human cytomegalovirus from latently infected myeloid cells and increase the risk for HCMV infection in D+R+ liver transplant patients.

    PubMed

    Van Damme, Ellen; Sauviller, Sarah; Lau, Betty; Kesteleyn, Bart; Griffiths, Paul; Burroughs, Andrew; Emery, Vincent; Sinclair, John; Van Loock, Marnix

    2015-01-01

    Graft rejection in transplant patients is managed clinically by suppressing T-cell function with immunosuppressive drugs such as prednisolone and methylprednisolone. In such immunocompromised hosts, human cytomegalovirus (HCMV) is an important opportunistic pathogen and can cause severe morbidity and mortality. Currently, the effect of glucocorticosteroids (GCSs) on the HCMV life cycle remains unclear. Previous reports showed enhanced lytic replication of HCMV in vitro in the presence of GCSs. In the present study, we explored the implications of steroid exposure on latency and reactivation. We observed a direct effect of several GCSs used in the clinic on the activation of a quiescent viral major immediate-early promoter in stably transfected THP-1 monocytic cells. This activation was prevented by the glucocorticoid receptor (GR) antagonist Ru486 and by shRNA-mediated knockdown of the GR. Consistent with this observation, prednisolone treatment of latently infected primary monocytes resulted in HCMV reactivation. Analysis of the phenotype of these cells showed that treatment with GCSs was correlated with differentiation to an anti-inflammatory macrophage-like cell type. On the basis that these observations may be pertinent to HCMV reactivation in post-transplant settings, we retrospectively evaluated the incidence, viral kinetics and viral load of HCMV in liver transplant patients in the presence or absence of GCS treatment. We observed that combination therapy of baseline prednisolone and augmented methylprednisolone, upon organ rejection, significantly increased the incidence of HCMV infection in the intermediate risk group where donor and recipient are both HCMV seropositive (D+R+) to levels comparable with the high risk D+R- group. PMID:25312585

  9. CD4+ T cell polyfunctional profile in HIV-TB coinfection are similar between individuals with latent and active TB infection

    PubMed Central

    Canaday, David H.; Sridaran, Sankar; Van Epps, Puja; Aung, Htin; Burant, Christopher J.; Nsereko, Mary; Mayanja-Kizza, Harriet; Betts, Michael R.; Toossi, Zahra

    2015-01-01

    CD4+ T cell counts of HIV-infected individuals with pulmonary TB (PTB) are higher than with other opportunistic infections suggesting that progression to PTB is not merely due to T cell depletion but also dysfunction. There are limited data examining T cell functional signatures in human HIV-TB co-infection particularly in PTB which accounts for about 80% of active TB disease overall. We examined a cohort of HIV-infected anti-retroviral naïve individuals in Kampala, Uganda, a TB endemic area using multi-parametric flow cytometry analysis to determine IFN-γ, IL-2, IL-17, and TNF-α production in CD4+ memory T cell subsets. The cytokine frequency and polyfunctionality profile of Mycobacterium tuberculosis (MTB)-specific CD4+ T cells in HIV-infected persons with latent TB infection (LTBI) or PTB is comparable. This similarity suggests that LTBI may represent a smoldering state of persistent MTB replication rather than dormant infection. This may be a contributory mechanism to the significantly increased risk of progression to PTB in this population. PMID:25956974

  10. Lytic Gene Expression Is Frequent in HSV-1 Latent Infection and Correlates with the Engagement of a Cell-Intrinsic Transcriptional Response

    PubMed Central

    Ma, Joel Z.; Russell, Tiffany A.; Spelman, Tim

    2014-01-01

    Herpes simplex viruses (HSV) are significant human pathogens that provide one of the best-described examples of viral latency and reactivation. HSV latency occurs in sensory neurons, being characterized by the absence of virus replication and only fragmentary evidence of protein production. In mouse models, HSV latency is especially stable but the detection of some lytic gene transcription and the ongoing presence of activated immune cells in latent ganglia have been used to suggest that this state is not entirely quiescent. Alternatively, these findings can be interpreted as signs of a low, but constant level of abortive reactivation punctuating otherwise silent latency. Using single cell analysis of transcription in mouse dorsal root ganglia, we reveal that HSV-1 latency is highly dynamic in the majority of neurons. Specifically, transcription from areas of the HSV genome associated with at least one viral lytic gene occurs in nearly two thirds of latently-infected neurons and more than half of these have RNA from more than one lytic gene locus. Further, bioinformatics analyses of host transcription showed that progressive appearance of these lytic transcripts correlated with alterations in expression of cellular genes. These data show for the first time that transcription consistent with lytic gene expression is a frequent event, taking place in the majority of HSV latently-infected neurons. Furthermore, this transcription is of biological significance in that it influences host gene expression. We suggest that the maintenance of HSV latency involves an active host response to frequent viral activity. PMID:25058429

  11. Early and sustained expression of latent and host modulating genes in coordinated transcriptional program of KSHV productive primary infection of human primary endothelial cells

    PubMed Central

    Yoo, Seung Min; Zhou, Fu-Chun; Ye, Feng-Chun; Pan, Hong-Yi; Gao, Shou-Jiang

    2009-01-01

    Coordinated expression of viral genes in primary infection is essential for successful infection of host cells. We examined the expression profiles of Kaposi’s sarcoma-associated herpesvirus (KSHV) transcripts in productive primary infection of primary human umbilical vein endothelial cells by whole-genome reverse-transcription real-time quantitative PCR. The latent transcripts were expressed early and sustained at high levels throughout the infection while the lytic transcripts were expressed in the order of immediate early, early, and lytic transcripts, all of which culminated before the production of infectious virions. Significantly, transcripts encoding genes with host modulating functions, including mitogenic and cell cycle-regulatory, immune-modulating, and anti-apoptotic genes, were expressed before those encoding viral structure and replication genes, and sustained at high levels throughout the infection, suggesting KSHV manipulation of host environment to facilitate infection. The KSHV transcriptional program in a primary infection defined in this study should provide a basis for further investigation of virus–cell interactions. PMID:16154170

  12. Investigation of Functional Activity of Cells in Granulomatous Inflammatory Lesions from Mice with Latent Tuberculous Infection in the New Ex Vivo Model

    PubMed Central

    2013-01-01

    The new ex vivo model system measuring functional input of individual granuloma cells to formation of granulomatous inflammatory lesions in mice with latent tuberculous infection has been developed and described in the current study. Monolayer cultures of cells that migrated from individual granulomas were established in the proposed culture settings for mouse spleen and lung granulomas induced by in vivo exposure to BCG vaccine. The cellular composition of individual granulomas was analyzed. The expression of the leukocyte surface markers such as phagocytic receptors CD11b, CD11c, CD14, and CD16/CD32 and the expression of the costimulatory molecules CD80, CD83, and CD86 were tested as well as the production of proinflammatory cytokines (IFNγ and IL-1α) and growth factors (GM-CSF and FGFb) for cells of individual granulomas. The colocalization of the phagocytic receptors and costimulatory molecules in the surface microdomains of granuloma cells (with and without acid-fast BCG-mycobacteria) has also been detected. It was found that some part of cytokine macrophage producers have carried acid-fast mycobacteria. Detected modulation in dynamics of production of pro-inflammatory cytokines, growth factors, and leukocyte surface markers by granuloma cells has indicated continued processes of activation and deactivation of granuloma inflammation cells during the latent tuberculous infection progress in mice. PMID:24198843

  13. Secreted Oral Epithelial Cell Membrane Vesicles Induce Epstein-Barr Virus Reactivation in Latently Infected B Cells

    PubMed Central

    Lin, Zhen; Swan, Kenneth; Zhang, Xin; Cao, Subing; Brett, Zoe; Drury, Stacy; Fewell, Claire; Puetter, Adriane; Wang, Xia; Ferris, MaryBeth; Sullivan, Deborah E.; Li, Li

    2016-01-01

    ABSTRACT In the oral epithelium, peripheral stores of Epstein-Barr virus (EBV) are transmitted from infiltrating B cells to epithelial cells. Once the virus is transmitted to epithelial cells, the highly permissive nature of this cell type for lytic replication allows virus amplification and exchange to other hosts. Since the initial transfer of EBV from B cells to epithelial cells requires transitioning of the B-cell to a state that induces virus reactivation, we hypothesized that there might be epithelium-specific signals that allow the infiltrating B cells to sense the appropriate environment to initiate reactivation and begin this exchange process. We previously found that the epithelium-specific miR-200 family of microRNAs promotes EBV lytic replication. Here we show that there are high levels of miR-200 family members in oral and tonsillar epithelia and in saliva. Analysis of cultured oral epithelial cells (OKF6) showed that they actively secrete membrane vesicles (exosomes) that are enriched with miR-200 family members. Coculturing of EBV-positive B cells with OKF6 cells induced viral reactivation. Further, treatment of EBV-positive B cells with OKF6 cell-derived membrane vesicles promoted reactivation. Using a cell system that does not naturally express miR-200 family members, we found that enforced expression of a miR-200 family member produced membrane vesicles that were able to induce the lytic cascade in EBV-positive B cells. We propose that membrane vesicles secreted by oral and tonsillar epithelial cells may serve as a tissue-specific environmental cue that initiates reactivation in B cells, promoting the transfer of virus from peripheral B-cell stores to the oral epithelium to facilitate virus amplification and exchange to other hosts. IMPORTANCE Epstein-Barr virus (EBV) is an important human pathogen that is causally associated with several lymphomas and carcinomas. The switch from latency to the lytic cycle is critical for successful host infection

  14. The Expression of Human Cytomegalovirus MicroRNA MiR-UL148D during Latent Infection in Primary Myeloid Cells Inhibits Activin A-triggered Secretion of IL-6

    PubMed Central

    Lau, Betty; Poole, Emma; Krishna, Benjamin; Sellart, Immaculada; Wills, Mark R.; Murphy, Eain; Sinclair, John

    2016-01-01

    The successful establishment and maintenance of human cytomegalovirus (HCMV) latency is dependent on the expression of a subset of viral genes. Whilst the exact spectrum and functions of these genes are far from clear, inroads have been made for protein-coding genes. In contrast, little is known about the expression of non-coding RNAs. Here we show that HCMV encoded miRNAs are expressed de novo during latent infection of primary myeloid cells. Furthermore, we demonstrate that miR-UL148D, one of the most highly expressed viral miRNAs during latent infection, directly targets the cellular receptor ACVR1B of the activin signalling axis. Consistent with this, we observed upregulation of ACVR1B expression during latent infection with a miR-UL148D deletion virus (ΔmiR-UL148D). Importantly, we observed that monocytes latently infected with ΔmiR-UL148D are more responsive to activin A stimulation, as demonstrated by their increased secretion of IL-6. Collectively, our data indicates miR-UL148D inhibits ACVR1B expression in latently infected cells to limit proinflammatory cytokine secretion, perhaps as an immune evasion strategy or to postpone cytokine-induced reactivation until conditions are more favourable. This is the first demonstration of an HCMV miRNA function during latency in primary myeloid cells, implicating that small RNA species may contribute significantly to latent infection. PMID:27491954

  15. Interaction between Endogenous Bacterial Flora and Latent HIV Infection

    PubMed Central

    Victoriano, Ann Florence B.; Imai, Kenichi

    2013-01-01

    Human commensal bacteria do not normally cause any diseases. However, in certain pathological conditions, they exhibit a number of curious behaviors. In HIV infection, these bacteria exhibit bidirectional relationships: whereas they cause opportunistic infections based on immunological deterioration, they also augment HIV replication, in particular, viral replication from latently infected cells, which is attributable to the effect of butyric acid produced by certain anaerobic bacteria by modifying the state of chromatin. Here, we review recent evidence supporting the contributory role of such endogenous microbes in disrupting HIV latency and its potential link to the clinical progression of AIDS. PMID:23616411

  16. Human Herpesvirus 6 Latently Infects Early Bone Marrow Progenitors In Vivo

    PubMed Central

    Luppi, Mario; Barozzi, Patrizia; Morris, Christine; Maiorana, Antonio; Garber, Richard; Bonacorsi, Goretta; Donelli, Amedea; Marasca, Roberto; Tabilio, Antonio; Torelli, Giuseppe

    1999-01-01

    We have studied the in vivo tropism of human herpesvirus 6 (HHV-6) for hemopoietic cells in patients with latent HHV-6 infection. Having used a variety of cell purification, molecular, cytogenetic, and immunocytochemical procedures, we report the first evidence that HHV-6 latently infects early bone marrow progenitor cells and that HHV-6 may be transmitted longitudinally to cells which differentiate along the committed pathways. PMID:9847383

  17. Potential of Radiation-Induced Cellular Stress for Reactivation of Latent HIV-1 and Killing of Infected Cells.

    PubMed

    Iordanskiy, Sergey; Kashanchi, Fatah

    2016-02-01

    The use of highly active antiretroviral therapy against HIV-1 for last two decades has reduced mortality of patients through extension of nonsymptomatic phase of infection. However, HIV-1 can be preserved in long-lived resting CD4(+) T cells, which form a viral reservoir in infected individuals, and potentially in macrophages and astrocytes. Reactivation of viral replication is critical since the host immune response in combination with antiretroviral therapy may eradicate the virus (shock and kill strategy). In this opinion piece, we consider potential application of therapeutic doses of irradiation, the well-known and effective stress signal that induces DNA damage and activates cellular stress response, to resolve two problems: activate HIV-1 replication and virion production in persistent reservoirs under cART and deplete infected cells through selective cell killing using DNA damage responses. PMID:26765533

  18. Latent porcine circovirus type 2-infected domestic pigs: A potential infection model for the effective development of vaccines against latent or chronic virus induced diseases.

    PubMed

    Sydler, Titus; Brägger, Stefanie; Handke, Martin; Hartnack, Sonja; Lewis, Fraser I; Sidler, Xaver; Brugnera, Enrico

    2016-02-17

    Until recently, knowledge of the pathogenicity of Circoviridae and Anelloviridae family members was limited. Our previous discoveries provided clues toward resolving this issue based on studies of the latent nature of porcine circovirus type 2 (PCV2) genotype group members. We developed a conventional pig infection model that indicated that weaners already harbored latent PCV2 infection in the thymus, which enabled the viruses to specifically modulate the maturation of T-helper cells. This finding raised the possibility that the thymi of normal fetuses were already infected with PCV2. The present findings further substantiate our hypothesis that PCV2 masquerades as the host by infecting fetuses before they acquire immune-competence. We provide the first demonstration that all domestic pig fetuses preferentially harbor latent PCV2-infected cells in their thymi. These PCV2-infected cells are different from thymocytes and are located in the medulla of the fetal thymus. These latent PCV2-infected cells in fetuses are found at the same location and share characteristics with the infected cells observed in adolescent pigs. Moreover, fetuses also harbor these infected cells in other lymph system organs. We provide the first demonstration that the fetal thymus virus pools are minimally affected by sow vaccination, highlighting the immune-privileged character of this organ. Furthermore, we found a striking reduction in virus-infected cells in the fetal spleen and an increase in PCV2-infected cells in the fetal intestine of anti-PCV2-vaccinated mothers. These data indicate that specific immune response interactions occur between mothers and their progeny that are not dependent on the humoral immunity of the mother and cannot be attributed to the rudimentary humoral responses of the fetuses because these pig fetuses do not have any PCV2-specific antibodies. These shifts in our understanding of the PCV2-infected cell pool will lead to different avenues in the search for

  19. Bacillus Calmette-Guérin (BCG) Revaccination of Adults with Latent Mycobacterium tuberculosis Infection Induces Long-Lived BCG-Reactive NK Cell Responses.

    PubMed

    Suliman, Sara; Geldenhuys, Hennie; Johnson, John L; Hughes, Jane E; Smit, Erica; Murphy, Melissa; Toefy, Asma; Lerumo, Lesedi; Hopley, Christiaan; Pienaar, Bernadette; Chheng, Phalkun; Nemes, Elisa; Hoft, Daniel F; Hanekom, Willem A; Boom, W Henry; Hatherill, Mark; Scriba, Thomas J

    2016-08-15

    One third of the global population is estimated to be latently infected with Mycobacterium tuberculosis We performed a phase I randomized controlled trial of isoniazid preventive therapy (IPT) before revaccination with bacillus Calmette-Guérin (BCG) in healthy, tuberculin skin test-positive (≥15-mm induration), HIV-negative South African adults. We hypothesized that preclearance of latent bacilli with IPT modulates BCG immunogenicity following revaccination. Frequencies and coexpression of IFN-γ, TNF-α, IL-2, IL-17, and/or IL-22 in CD4 T cells and IFN-γ-expressing CD8 T, γδ T, CD3(+)CD56(+) NKT-like, and NK cells in response to BCG were measured using whole blood intracellular cytokine staining and flow cytometry. We analyzed 72 participants who were revaccinated with BCG after IPT (n = 33) or without prior IPT (n = 39). IPT had little effect on frequencies or cytokine coexpression patterns of M. tuberculosis- or BCG-specific responses. Revaccination transiently boosted BCG-specific Th1 cytokine-expressing CD4, CD8, and γδ T cells. Despite high frequencies of IFN-γ-expressing BCG-reactive CD3(+)CD56(+) NKT-like cells and CD3(-)CD56(dim) and CD3(-)CD56(hi) NK cells at baseline, BCG revaccination boosted these responses, which remained elevated up to 1 y after revaccination. Such BCG-reactive memory NK cells were induced by BCG vaccination in infants, whereas in vitro IFN-γ expression by NK cells upon BCG stimulation was dependent on IL-12 and IL-18. Our data suggest that isoniazid preclearance of M. tuberculosis bacilli has little effect on the magnitude, persistence, or functional attributes of lymphocyte responses boosted by BCG revaccination. Our study highlights the surprising durability of BCG-boosted memory NKT-like and NK cells expressing antimycobacterial effector molecules, which may be novel targets for tuberculosis vaccines. PMID:27412415

  20. HIV-1 integration landscape during latent and active infection

    PubMed Central

    Cohn, Lillian; Silva, Israel T.; Oliveira, Thiago Y.; Rosales, Rafael A.; Parrish, Erica H.; Learn, Gerald H.; Hahn, Beatrice H.; Czartoski, Julie L.; McElrath, M. Juliana; Lehmann, Clara; Klein, Florian; Caskey, Marina; Walker, Bruce D.; Siliciano, Janet D.; Siliciano, Robert F.; Jankovic, Mila; Nussenzweig, Michel C.

    2015-01-01

    SUMMARY The barrier to curing HIV-1 is thought to reside primarily in CD4+ T cells containing silent proviruses. To characterize these latently infected cells, we studied the integration profile of HIV-1 in viremic progressors, individuals receiving antiretroviral therapy, and viremic controllers. Clonally expanded T cells represented the majority of all integrations and increased during therapy. However, none of the 75 expanded T cell clones assayed contained intact virus. In contrast, the cells bearing single integration events decreased in frequency over time on therapy, and the surviving cells were enriched for HIV-1 integration in silent regions of the genome. Finally, there was a strong preference for integration into, or in close proximity to Alu repeats, which were also enriched in local hotspots for integration. The data indicate that dividing clonally expanded T cells contain defective proviruses, and that the replication competent reservoir is primarily found in CD4+ T cells that remain relatively quiescent. PMID:25635456

  1. RNA-guided endonuclease provides a therapeutic strategy to cure latent herpesviridae infection

    PubMed Central

    Wang, Jianbin; Quake, Stephen R.

    2014-01-01

    Latent viral infection is a persistent cause of human disease. Although standard antiviral therapies can suppress active viral replication, no existing treatment can effectively eradicate latent infection and therefore a cure is lacking for many prevalent viral diseases. The prokaryotic immune system clustered regularly interspaced short palindromic repeat (CRISPR)/Cas evolved as a natural response to phage infections, and we demonstrate here that the CRISPR/Cas9 system can be adapted for antiviral treatment in human cells by specifically targeting the genomes of latent viral infections. Patient-derived cells from a Burkitt’s lymphoma with latent Epstein–Barr virus infection showed dramatic proliferation arrest and a concomitant decrease in viral load after exposure to a CRISPR/Cas9 vector targeted to the viral genome. PMID:25157128

  2. The Effects of Age and Latent Cytomegalovirus Infection on NK-Cell Phenotype and Exercise Responsiveness in Man

    PubMed Central

    Bigley, Austin B.; Spielmann, Guillaume; Agha, Nadia; Simpson, Richard J.

    2015-01-01

    The redeployment of NK-cells in response to an acute bout of exercise is thought to be an integral component of the “fight-or-flight” response, preparing the body for potential injury or infection. We showed previously that CMV seropositivity impairs the redeployment of NK-cells with exercise in the young. In the current study, we examined the effect of aging on the redeployment of NK-cells with exercise in the context of CMV. We show here that CMV blunts the exercise-induced redeployment of NK-cells in both younger (23–39 yrs) and older (50–64 yrs) subjects with older CMVneg subjects showing the largest postexercise mobilization and 1 h postexercise egress of NK-cells. The blunted exercise response in CMVpos individuals was associated with a decreased relative redeployment of the CD158a+ and CD57+ NK-cell subsets in younger and older individuals. In addition, we show that aging is associated with a CMV-independent increase in the proportion of NK-cells expressing the terminal differentiation marker CD57, while CMV is associated with an age-dependent decrease in the proportion of NK-cells expressing the inhibitory receptors KLRG1 (in the younger group) and CD158a (in the older group). Collectively, these data suggest that CMV may decrease NK-cell mediated immunosurveillance after exercise in both younger and older individuals. PMID:26583066

  3. The Effects of Age and Latent Cytomegalovirus Infection on NK-Cell Phenotype and Exercise Responsiveness in Man.

    PubMed

    Bigley, Austin B; Spielmann, Guillaume; Agha, Nadia; Simpson, Richard J

    2015-01-01

    The redeployment of NK-cells in response to an acute bout of exercise is thought to be an integral component of the "fight-or-flight" response, preparing the body for potential injury or infection. We showed previously that CMV seropositivity impairs the redeployment of NK-cells with exercise in the young. In the current study, we examined the effect of aging on the redeployment of NK-cells with exercise in the context of CMV. We show here that CMV blunts the exercise-induced redeployment of NK-cells in both younger (23-39 yrs) and older (50-64 yrs) subjects with older CMV(neg) subjects showing the largest postexercise mobilization and 1 h postexercise egress of NK-cells. The blunted exercise response in CMV(pos) individuals was associated with a decreased relative redeployment of the CD158a+ and CD57+ NK-cell subsets in younger and older individuals. In addition, we show that aging is associated with a CMV-independent increase in the proportion of NK-cells expressing the terminal differentiation marker CD57, while CMV is associated with an age-dependent decrease in the proportion of NK-cells expressing the inhibitory receptors KLRG1 (in the younger group) and CD158a (in the older group). Collectively, these data suggest that CMV may decrease NK-cell mediated immunosurveillance after exercise in both younger and older individuals. PMID:26583066

  4. Acute exercise preferentially redeploys NK-cells with a highly-differentiated phenotype and augments cytotoxicity against lymphoma and multiple myeloma target cells. Part II: impact of latent cytomegalovirus infection and catecholamine sensitivity.

    PubMed

    Bigley, Austin B; Rezvani, Katayoun; Pistillo, Mira; Reed, Justin; Agha, Nadia; Kunz, Hawley; O'Connor, Daniel P; Sekine, Takuya; Bollard, Catherine M; Simpson, Richard J

    2015-10-01

    We showed previously that acute exercise is associated with a preferential redeployment of highly-differentiated NK-cells and increased cytotoxicity against HLA-expressing tumor cell lines during exercise recovery. In this part II study, we retrospectively analyzed these findings in the context of latent cytomegalovirus (CMV) infection and performed additional experiments to explore potential mechanisms underpinning the marked reduction in NK-cell redeployment with exercise in CMV-seropositive individuals. We show here that latent CMV infection impairs NK-cell mobilization with exercise, only when the intensity of the exercise bout exceeds the individual blood lactate threshold (BLT). This impaired mobilization is associated with increased proportions of poorly exercise-responsive NK-cell subsets (NKG2C+/KIR-, NKG2C+/NKG2A-, and NKG2C+/CD57+) and decreased NK-cell β(2)-adrenergic receptor (AR) expression in those with CMV. As a result, NK-cell production of cyclic AMP (cAMP) in response to in vitro isoproterenol (synthetic β-agonist) stimulation was drastically lower in those with CMV (6.0 vs. 20.3pmol/mL, p<0.001) and correlated highly with the proportion of NKG2C+/CD57+ NK-cells (R(2)=0.97). Moreover, NK-cell cytotoxic activity (NKCA) against the K562 (36.6% vs. 22.7%, p<0.05), U266 (23.6% vs. 15.9%, p<0.05), and 221.AEH (41.3% vs. 13.3%, p<0.001) cell lines was increased at baseline in those infected with CMV; however, latent CMV infection abated the post-exercise increase in NKCA as a result of decreased NK-cell mobilization. Additionally, NKCA per cell against the U266 (0.24 vs. 0.12, p<0.01), RPMI-8226 (0.17 vs. 0.11, p<0.05), and 221.AEH (0.18 vs. 0.11, p<0.05) cell lines was increased 1h post-exercise (relative to baseline) in CMV-seronegative subjects, but not in those infected with CMV. Collectively, these data indicate that latent CMV infection may compromise NK-cell mediated immunosurveillance after acute exercise due to an increased proportion of

  5. In Vitro Immunomodulation of a Whole Blood IFN-γ Release Assay Enhances T Cell Responses in Subjects with Latent Tuberculosis Infection

    PubMed Central

    Gaur, Rajiv L.; Suhosk, Megan M.; Banaei, Niaz

    2012-01-01

    Background Activation of innate immunity via pathogen recognition receptors (PRR) modulates adaptive immune responses. PRR ligands are being exploited as vaccine adjuvants and as therapeutics, but their utility in diagnostics has not been explored. Interferon-gamma (IFN-γ) release assays (IGRAs) are functional T cell assays used to diagnose latent tuberculosis infection (LTBI); however, novel approaches are needed to improve their sensitivity. Methods In vitro immunomodulation of a whole blood IGRA (QuantiFERON®-TB GOLD In-Tube) with Toll-like receptor agonists poly(I:C), LPS, and imiquimod was performed on blood from subjects with LTBI and negative controls. Results In vitro immunomodulation significantly enhanced the response of T cells stimulated with M. tuberculosis antigens from subjects with LTBI but not from uninfected controls. Immunomodulation of IGRA revealed T cell responses in subjects with LTBI whose T cells otherwise do not respond to in vitro stimulation with antigens alone. Similar to their in vivo functions, addition of poly(I:C) and LPS to whole blood induced secretion of inflammatory cytokines and IFN-α and enhanced the surface expression of antigen presenting and costimulatory molecules on antigen presenting cells. Conclusions In vitro immunomodulation of whole blood IGRA may be an effective strategy for enhancing the sensitivity of T cells for diagnosis of LTBI. PMID:23144722

  6. Latent Tuberculosis Infection: Myths, Models, and Molecular Mechanisms

    PubMed Central

    Dutta, Noton K.

    2014-01-01

    SUMMARY The aim of this review is to present the current state of knowledge on human latent tuberculosis infection (LTBI) based on clinical studies and observations, as well as experimental in vitro and animal models. Several key terms are defined, including “latency,” “persistence,” “dormancy,” and “antibiotic tolerance.” Dogmas prevalent in the field are critically examined based on available clinical and experimental data, including the long-held beliefs that infection is either latent or active, that LTBI represents a small population of nonreplicating, “dormant” bacilli, and that caseous granulomas are the haven for LTBI. The role of host factors, such as CD4+ and CD8+ T cells, T regulatory cells, tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ), in controlling TB infection is discussed. We also highlight microbial regulatory and metabolic pathways implicated in bacillary growth restriction and antibiotic tolerance under various physiologically relevant conditions. Finally, we pose several clinically important questions, which remain unanswered and will serve to stimulate future research on LTBI. PMID:25184558

  7. Current treatment options for latent tuberculosis infection.

    PubMed

    Bocchino, Marialuisa; Matarese, Alessandro; Sanduzzi, Alessandro

    2014-05-01

    Treatment of latent tuberculosis infection (LTBI) is a key component in TB control strategies worldwide. However, as people with LTBI are neither symptomatic nor contagious, any screening decision should be weighed carefully against the potential benefit of preventing active disease in those who are known to be at higher risk and are willing to accept therapy for LTBI. This means that a targeted approach is desirable to maximize cost effectiveness and to guarantee patient adherence. We focus on LTBI treatment strategies in patient populations at increased risk of developing active TB, including candidates for treatment with tumor necrosis factor-α blockers. In the last 40 years, isoniazid (INH) has represented the keystone of LTBI therapy across the world. Although INH remains the first therapeutic option, alternative treatments that are effective and associated with increased adherence and economic savings are available. Current recommendations, toxicity, compliance, and cost issues are discussed in detail in this review. A balanced relationship between the patient and healthcare provider could increase adherence, while cost-saving treatment strategies with higher effectiveness, fewer side effects, and of shorter duration should be offered as preferred. PMID:24789003

  8. Impact of latent infection treatment in indigenous populations.

    PubMed

    Yuhara, Lucia Suemi; Sacchi, Flávia Patussi Correia; Croda, Julio

    2013-01-01

    The aims of the present study were to identify risk factors associated with latent tuberculosis (TB), examine the development of active disease among contacts, and assess the effectiveness of treating latent infection in indigenous Brazilians from January 2006 to December 2011. This was a retrospective study consisting of 1,371 tuberculosis contacts, 392 of whom underwent treatment for latent infection. Morbidity-from-TB data were obtained from the Information System for Disease Notification (SINAN) database, and the contacts' data were collected from the clinical records using forms employed by Special Department of Indigenous Health (SESAI) multidisciplinary teams, according to SESAI's instructions. The variables that were associated with latent infection among the contacts were age (odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.02-1.04) and close contact with a smear-positive index case (OR: 2.26, 95% CI: 1.59-3.22). The variables associated with the development of active TB among the contacts were a tuberculin skin test (TST) ≥10 mm (relative risk [RR]: 1.12, 95% CI: 1.07-1.17), age (RR: 1.01, 95% CI: 1.00-1.03), and treatment of latent infection (RR: 0.03, 95% CI: 0.01-0.27). The estimated number of latent infection treatments needed to prevent one case of active TB among the contacts was 51 treatments (95% CI: 33-182). In contacts with TST ≥10 mm, 10 (95% CI: 6-19) latent infection treatments were necessary to prevent one case of active TB. Age and close contact with a smear-positive index case were associated with latent TB. Screening with TST is a high priority among individuals contacting smear-positive index cases. Age and TST are associated with the development of active TB among contacts, and treatment of latent infection is an effective measure to control TB in indigenous communities. PMID:23936264

  9. T-Cell Immunophenotyping Distinguishes Active From Latent Tuberculosis

    PubMed Central

    Pollock, Katrina M.; Whitworth, Hilary S.; Montamat-Sicotte, Damien J.; Grass, Lisa; Cooke, Graham S.; Kapembwa, Moses S.; Kon, Onn M.; Sampson, Robert D.; Taylor, Graham P.; Lalvani, Ajit

    2013-01-01

    Background. Changes in the phenotype and function of Mycobacterium tuberculosis (M. tuberculosis)-specific CD4+ and CD8+ T-cell subsets in response to stage of infection may allow discrimination between active tuberculosis and latent tuberculosis infection. Methods. A prospective comparison of M. tuberculosis-specific cellular immunity in subjects with active tuberculosis and latent tuberculosis infection, with and without human immunodeficiency virus (HIV) coinfection. Polychromatic flow cytometry was used to measure CD4+ and CD8+ T-cell subset phenotype and secretion of interferon γ (IFN-γ), interleukin 2 (IL-2), and tumor necrosis factor α (TNF-α). Results. Frequencies of CD4+ and CD8+ cells secreting IFN-γ-only, TNF-α-only and dual IFN-γ/TNF-α were greater in active tuberculosis vs latent tuberculosis infection. All M. tuberculosis-specific CD4+ subsets, with the exception of IL-2-only cells, switched from central to effector memory phenotype in active tuberculosis vs latent tuberculosis infection, accompanied by a reduction in IL-7 receptor α (CD127) expression. The frequency of PPD-specific CD4+ TNF-α-only-secreting T cells with an effector phenotype accurately distinguished active tuberculosis from latent tuberculosis infection with an area under the curve of 0.99, substantially more discriminatory than measurement of function alone. Conclusions. Combined measurement of T-cell phenotype and function defines a highly discriminatory biomarker of tuberculosis disease activity. Unlocking the diagnostic and monitoring potential of this combined approach now requires validation in large-scale prospective studies. PMID:23966657

  10. Treatment guidelines for latent tuberculosis infection.

    PubMed

    2014-01-01

    The treatment of latent tuberculosis infection (LTBI) has been established as valid for patients at high risk for developing active tuberculosis. Treatment of LTBI is also considered an important strategy for eliminating tuberculosis (TB) in Japan. In recent years, interferon-gamma release assays have come into widespread use; isoniazid (INH) preventive therapy for HIV patients has come to be recommended worldwide; and there have been increases in both types of biologics used in the treatment of immune diseases as well as the diseases susceptible to treatment. In light of the above facts, the Prevention Committee and the Treatment Committee of the Japanese Society for Tuberculosis have jointly drafted these guidelines. In determining subjects for LTBI treatment, the following must be considered: 1) risk of TB infection/ development; 2) infection diagnosis; 3) chest image diagnosis; 4) the impact of TB development; 5) the possible manifestation of side effects; and 6) the prospects of treatment completion. LTBI treatment is actively considered when relative risk is deemed 4 or higher, including risk factors such as the following: HIV/AIDS, organ transplants (immunosuppressant use), silicosis, dialysis due to chronic renal failure, recent TB infection (within 2 years), fibronodular shadows in chest radiographs (untreated old TB), the use of biologics, and large doses of corticosteroids. Although the risk is lower, the following risk factors require consideration of LTBI treatment when 2 or more of them are present: use of oral or inhaled corticosteroids, use of other immunosuppressants, diabetes, being underweight, smoking, gastrectomy, and so on. In principle, INH is administered for a period of 6 or 9 months. When INH cannot be used, rifampicin is administered for a period of 4 or 6 months. It is believed that there are no reasons to support long-term LTBI treatment for immunosuppressed patients in Japan, where the risk of infection is not considered markedly high

  11. Tuberculin Skin Testing Compared with T-Cell Responses to Mycobacterium tuberculosis-Specific and Nonspecific Antigens for Detection of Latent Infection in Persons with Recent Tuberculosis Contact

    PubMed Central

    Arend, Sandra M.; Engelhard, Anrik C. F.; Groot, Gertjan; de Boer, Kirsten; Andersen, Peter; Ottenhoff, Tom H. M.; van Dissel, Jaap T.

    2001-01-01

    The tuberculin skin test (TST) is used for the identification of latent tuberculosis (TB) infection (LTBI) but lacks specificity in Mycobacterium bovis BCG-vaccinated individuals, who constitute an increasing proportion of TB patients and their contacts from regions where TB is endemic. In previous studies, T-cell responses to ESAT-6 and CFP-10, M. tuberculosis-specific antigens that are absent from BCG, were sensitive and specific for detection of active TB. We studied 44 close contacts of a patient with smear-positive pulmonary TB and compared the standard screening procedure for LTBI by TST or chest radiographs with T-cell responses to M. tuberculosis-specific and nonspecific antigens. Peripheral blood mononuclear cells were cocultured with ESAT-6, CFP-10, TB10.4 (each as recombinant antigen and as a mixture of overlapping synthetic peptides), M. tuberculosis sonicate, purified protein derivative (PPD), and short-term culture filtrate, using gamma interferon production as the response measure. LTBI screening was by TST in 36 participants and by chest radiographs in 8 persons. Nineteen contacts were categorized as TST negative, 12 were categorized as TST positive, and 5 had indeterminate TST results. Recombinant antigens and peptide mixtures gave similar results. Responses to TB10.4 were neither sensitive nor specific for LTBI. T-cell responses to ESAT-6 and CFP-10 were less sensitive for detection of LTBI than those to PPD (67 versus 100%) but considerably more specific (100 versus 72%). The specificity of the TST or in vitro responses to PPD will be even less when the proportion of BCG-vaccinated persons among TB contacts evaluated for LTBI increases. PMID:11687445

  12. Latent Herpes Simplex Virus 1 Infection Does Not Induce Apoptosis in Human Trigeminal Ganglia

    PubMed Central

    Lindemann, Anja; Sinicina, Inga; Strupp, Michael; Brandt, Thomas; Hüfner, Katharina

    2015-01-01

    Herpes simplex virus 1 (HSV-1) can establish lifelong latency in human trigeminal ganglia. Latently infected ganglia contain CD8+ T cells, which secrete granzyme B and are thus capable of inducing neuronal apoptosis. Using immunohistochemistry and single-cell reverse transcription-quantitative PCR (RT-qPCR), higher frequency and transcript levels of caspase-3 were found in HSV-1-negative compared to HSV-1-positive ganglia and neurons, respectively. No terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay-positive neurons were detected. The infiltrating T cells do not induce apoptosis in latently infected neurons. PMID:25762734

  13. Restricted expression of herpes simplex virus lytic genes during establishment of latent infection by thymidine kinase-negative mutant viruses.

    PubMed Central

    Kosz-Vnenchak, M; Coen, D M; Knipe, D M

    1990-01-01

    Infection of cells by herpes simplex virus (HSV) can lead to either lytic, productive infection or nonlytic, latent infection. The factors influencing this infection pathway decision are largely unknown. Thymidine kinase-negative mutant viruses can establish latent infection in neurons of mouse trigeminal ganglia but do not replicate productively in these cells. We show that during the early stages of establishment of latency by these mutants, expression of viral lytic genes is drastically reduced or undetectable as assayed by in situ hybridization. Thus, establishment of latent infection by HSV can occur despite severely restricted levels of lytic gene expression. This suggests that the block to productive replication during establishment of latent infection by HSV occurs before or early during the expression of alpha genes. Images PMID:2170678

  14. Impact of Latent Infection Treatment in Indigenous Populations

    PubMed Central

    Yuhara, Lucia Suemi; Sacchi, Flávia Patussi Correia; Croda, Julio

    2013-01-01

    The aims of the present study were to identify risk factors associated with latent tuberculosis (TB), examine the development of active disease among contacts, and assess the effectiveness of treating latent infection in indigenous Brazilians from January 2006 to December 2011. This was a retrospective study consisting of 1,371 tuberculosis contacts, 392 of whom underwent treatment for latent infection. Morbidity-from-TB data were obtained from the Information System for Disease Notification (SINAN) database, and the contacts’ data were collected from the clinical records using forms employed by Special Department of Indigenous Health (SESAI) multidisciplinary teams, according to SESAI’s instructions. The variables that were associated with latent infection among the contacts were age (odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.02–1.04) and close contact with a smear-positive index case (OR: 2.26, 95% CI: 1.59–3.22). The variables associated with the development of active TB among the contacts were a tuberculin skin test (TST) ≥10 mm (relative risk [RR]: 1.12, 95% CI: 1.07–1.17), age (RR: 1.01, 95% CI: 1.00–1.03), and treatment of latent infection (RR: 0.03, 95% CI: 0.01–0.27). The estimated number of latent infection treatments needed to prevent one case of active TB among the contacts was 51 treatments (95% CI: 33–182). In contacts with TST ≥10 mm, 10 (95% CI: 6–19) latent infection treatments were necessary to prevent one case of active TB. Age and close contact with a smear-positive index case were associated with latent TB. Screening with TST is a high priority among individuals contacting smear-positive index cases. Age and TST are associated with the development of active TB among contacts, and treatment of latent infection is an effective measure to control TB in indigenous communities. PMID:23936264

  15. Measurement of phenotype and absolute number of circulating heparin-binding hemagglutinin, ESAT-6 and CFP-10, and purified protein derivative antigen-specific CD4 T cells can discriminate active from latent tuberculosis infection.

    PubMed

    Hutchinson, Paul; Barkham, Timothy M S; Tang, Wenying; Kemeny, David M; Chee, Cynthia Bin-Eng; Wang, Yee T

    2015-02-01

    The tuberculin skin test (TST) and interferon gamma (IFN-γ) release assays (IGRAs) are used as adjunctive tests for the evaluation of suspected cases of active tuberculosis (TB). However, a positive test does not differentiate latent from active TB. We investigated whether flow cytometric measurement of novel combinations of intracellular cytokines and surface makers on CD4 T cells could differentiate between active and latent TB after stimulation with Mycobacterium tuberculosis-specific proteins. Blood samples from 60 patients referred to the Singapore Tuberculosis Control Unit for evaluation for active TB or as TB contacts were stimulated with purified protein derivative (PPD), ESAT-6 and CFP-10, or heparin-binding hemagglutinin (HBHA). The CD4 T cell cytokine response (IFN-γ, interleukin-2 [IL-2], interleukin-17A [IL-17A], interleukin-22 [IL-22], granulocyte-macrophage colony-stimulating factor [GM-CSF], and tumor necrosis factor alpha [TNF-α]) and surface marker expression (CD27, CXCR3, and CD154) were then measured. We found that the proportion of PPD-specific CD4 T cells, defined as CD154(+) TNF-α(+) cells that were negative for CD27 and positive for GM-CSF, gave the strongest discrimination between subjects with latent and those with active TB (area under the receiver operator characteristic [ROC] curve of 0.9277; P < 0.0001). Also, the proportions and absolute numbers of HBHA-specific CD4 T cells were significantly higher in those with latent TB infection, particularly CD154(+) TNF-α(+) IFN-γ(+) IL-2(+) and CD154(+) TNF-α(+) CXCR3(+). Finally, we found that the ratio of ESAT-6- and CFP-10-responding to HBHA-responding CD4 T cells was significantly different between the two study populations. In conclusion, we found novel markers of M. tuberculosis-specific CD4 cells which differentiate between active and latent TB. PMID:25520147

  16. Discriminating Active Tuberculosis from Latent Tuberculosis Infection by flow cytometric measurement of CD161-expressing T cells

    PubMed Central

    Yang, Qianting; Xu, Qian; Chen, Qi; Li, Jin; Zhang, Mingxia; Cai, Yi; Liu, Haiying; Zhou, Yiping; Deng, Guofang; Deng, Qunyi; Zhou, Boping; Kornfeld, Hardy; Chen, Xinchun

    2015-01-01

    Interferon-gamma Release Assays (IGRAs) significantly increases the possibility for early diagnosis of tuberculosis, but IGRAs alone cannot discriminate active TB from LTBI. Therefore, fast and reliable discrimination of active tuberculosis, especially bacteriology negative tuberculosis, from LTBI is a great necessity. Here we established an assay based on flow cytometric multiparameter assay assessing expression of CD161 along with CD3, CD4, and CD8, whereby a set of indices formulated by the percentages of CD3+CD161+, CD3+CD4+CD161+ and CD3+CD8+CD161+ T cells multiplied with lymphocyte/monocyte ratio were established. Application of the CD3+CD8+CD161+ index to compare a cohort of active tuberculosis with a cohort of LTBI or health control yielded 0.7662 (95% confidence interval [CI] 0.6559–0.8552) or 0.7922 (95%  CI 0.6846–0.8763) for sensitivity and 0.9048 (95%  CI 0.8209–0.9580) or 0.8939 (95% CI 0.8392–0.9349) for specificity when the TB cohort was AFB+; the corresponding results were 0.7481 (95%  CI 0.6648–0.8198) or 0.7557 (95%  CI 0.6730–0.8265) for sensitivity and 0.8571 (95%  CI 0.7637–0.9239) or 0.8603 (95%  CI 0.8008–0.9075) for specificity when the TB cohort was AFB−. Our results reveal that in combination with IGRAs, CD161-based indices provide a novel, fast diagnostic solution addressing the limitation of current tuberculosis diagnostics. PMID:26643453

  17. HIV gene expression from intact proviruses positioned in bacterial artificial chromosomes at integration sites previously identified in latently infected T cells

    SciTech Connect

    Eipers, Peter G.; Salazar-Gonzalez, Jesus F.; Morrow, Casey D.

    2011-02-05

    HIV integration predominantly occurs in introns of transcriptionally active genes. To study the impact of the integration site on HIV gene expression, a complete HIV-1 provirus (with GFP as a fusion with Nef) was inserted into bacterial artificial chromosomes (BACs) at three sites previously identified in latent T cells of patients: topoisomerase II (Top2A), DNA methyltransferase 1 (DNMT1), or basic leucine transcription factor 2 (BACH2). Transfection of BAC-HIV into 293 T cells resulted in a fourfold difference in production of infectious HIV-1. Cell lines were established that contained BAC-Top2A, BAC-DNMT1, or BAC-BACH2, but only BAC-DNMT1 spontaneously produced virus, albeit at a low level. Stimulation with TNF-{alpha} resulted in virus production from four of five BAC-Top2A and all BAC-DNMT1 cell lines, but not from the BAC-BACH2 lines. The results of these studies highlight differences between integration sites identified in latent T cells to support virus production and reactivation from latency.

  18. Microscopic Analyses of Latent and Visible Monilinia fructicola Infections in Nectarines

    PubMed Central

    Garcia-Benitez, Carlos; Melgarejo, Paloma; De Cal, Antonieta; Fontaniella, Blanca

    2016-01-01

    Little is known about the histologic features of a latent Monilinia fructicola infection and brown rot in infected fruit. This report informs on the results of an investigation whose aim was to analyze the microanatomy of nectarines with a latent and visible M. fructicola infection. Mature nectarines were inoculated with an M. fructicola isolate and incubated at 25°C for 0, 24, 48, 72, or 96 hours in the dark. For investigating the latent infection process, the inoculated nectarines were first incubated at 25°C for 24 hours in the dark and then incubated at 4°C for 72, 144, 216, and 288 hours in the dark. At the end of the incubation, samples of nectarine tissue were excised from the inoculation points and prepared for light and transmission electron microscopic examinations. No signs of disease were seen on the surface of nectarines with a latent infection over the 288-hour incubation period. When the tissue samples were microscopically examined, M. fructicola colonized the stomata and this stomatal colonization progressively increased over time and was associated with gradual collapse of the epidermal cells and colonization of the subepidermis. In nectarines with visible brown rot, the disease usually appeared after 24 hours on the surface and in the uppermost layers of epidermal cells, which began to collapse after 48 hours. Subsequently, the diseased tissues of the nectarines displayed (a) colonization of the epidermis and mesocarp by M. fructicola with thin and thick hyphae, (b) collapse and disruption of epidermal and mesocarpic cells, (c) lysogenic cavities in the subepidermis and mesocarp, (d) degradation of the cuticle and epidermis, and (e) M. fructicola sporulation. M. fructicola is active during latent infections because slow and progressive colonization of nectarine subcuticular cells by the fungus occurs. PMID:27494620

  19. Characterization of Omental Immune Aggregates during Establishment of a Latent Gammaherpesvirus Infection

    PubMed Central

    Gray, Kathleen S.; Collins, Christopher M.; Speck, Samuel H.

    2012-01-01

    Herpesviruses are characterized by their ability to establish lifelong latent infection. The gammaherpesvirus subfamily is distinguished by lymphotropism, establishing and maintaining latent infection predominantly in B lymphocytes. Consequently, gammaherpesvirus pathogenesis is closely linked to normal B cell physiology. Murine gammaherpesvirus 68 (MHV68) pathogenesis in laboratory mice has been extensively studied as a model system to gain insights into the nature of gammaherpesvirus infection in B cells and their associated lymphoid compartments. In addition to B cells, MHV68 infection of macrophages contributes significantly to the frequency of viral genome-positive cells in the peritoneal cavity throughout latency. The omentum, a sheet of richly-vascularized adipose tissue, resides in the peritoneal cavity and contains clusters of immune cell aggregates termed milky spots. Although the value of the omentum in surgical wound-healing has long been appreciated, the unique properties of this tissue and its contribution to both innate and adaptive immunity have only recently been recognized. To determine whether the omentum plays a role in gammaherpesvirus pathogenesis we examined this site during early MHV68 infection and long-term latency. Following intraperitoneal infection, immune aggregates within the omentum expanded in size and number and contained virus-infected cells. Notably, a germinal-center B cell population appeared in the omentum of infected animals with earlier kinetics and greater magnitude than that observed in the spleen. Furthermore, the omentum harbored a stable frequency of viral genome-positive cells through early and into long-term latency, while removal of the omentum prior to infection resulted in a slight decrease in the establishment of splenic latency following intraperitoneal infection. These data provide the first evidence that the omentum is a site of chronic MHV68 infection that may contribute to the maintenance of chronic infection

  20. Characterization of a Latent Virus-Like Infection of Symbiotic Zooxanthellae▿

    PubMed Central

    Lohr, Jayme; Munn, Colin B.; Wilson, William H.

    2007-01-01

    A latent virus-like agent, which we designated zooxanthella filamentous virus 1 (ZFV1), was isolated from Symbiodinium sp. strain CCMP 2465 and characterized. Transmission electron microscopy and analytical flow cytometry revealed the presence of a new group of distinctive filamentous virus-like particles after exposure of the zooxanthellae to UV light. Examination of thin sections of the zooxanthellae revealed the formation and proliferation of filamentous virus-like particles in the UV-induced cells. Assessment of Symbiodinium sp. cultures was used here as a model to show the effects of UV irradiance and induction of potential latent viruses. The unique host-virus system described here provides insight into the role of latent infections in zooxanthellae through environmentally regulated viral induction mechanisms. PMID:17351090

  1. Characterization of a latent virus-like infection of symbiotic zooxanthellae.

    PubMed

    Lohr, Jayme; Munn, Colin B; Wilson, William H

    2007-05-01

    A latent virus-like agent, which we designated zooxanthella filamentous virus 1 (ZFV1), was isolated from Symbiodinium sp. strain CCMP 2465 and characterized. Transmission electron microscopy and analytical flow cytometry revealed the presence of a new group of distinctive filamentous virus-like particles after exposure of the zooxanthellae to UV light. Examination of thin sections of the zooxanthellae revealed the formation and proliferation of filamentous virus-like particles in the UV-induced cells. Assessment of Symbiodinium sp. cultures was used here as a model to show the effects of UV irradiance and induction of potential latent viruses. The unique host-virus system described here provides insight into the role of latent infections in zooxanthellae through environmentally regulated viral induction mechanisms. PMID:17351090

  2. CRISPR/Cas9-Mediated Genome Editing of Herpesviruses Limits Productive and Latent Infections

    PubMed Central

    van Diemen, Ferdy R.; Bruggeling, Carlijn E.; Schürch, Anita C.; van Ham, Petra M.; Imhof, Saskia M.; Nijhuis, Monique; Wiertz, Emmanuel J. H. J.; Lebbink, Robert Jan

    2016-01-01

    Herpesviruses infect the majority of the human population and can cause significant morbidity and mortality. Herpes simplex virus (HSV) type 1 causes cold sores and herpes simplex keratitis, whereas HSV-2 is responsible for genital herpes. Human cytomegalovirus (HCMV) is the most common viral cause of congenital defects and is responsible for serious disease in immuno-compromised individuals. Epstein-Barr virus (EBV) is associated with infectious mononucleosis and a broad range of malignancies, including Burkitt’s lymphoma, nasopharyngeal carcinoma, Hodgkin’s disease, and post-transplant lymphomas. Herpesviruses persist in their host for life by establishing a latent infection that is interrupted by periodic reactivation events during which replication occurs. Current antiviral drug treatments target the clinical manifestations of this productive stage, but they are ineffective at eliminating these viruses from the infected host. Here, we set out to combat both productive and latent herpesvirus infections by exploiting the CRISPR/Cas9 system to target viral genetic elements important for virus fitness. We show effective abrogation of HCMV and HSV-1 replication by targeting gRNAs to essential viral genes. Simultaneous targeting of HSV-1 with multiple gRNAs completely abolished the production of infectious particles from human cells. Using the same approach, EBV can be almost completely cleared from latently infected EBV-transformed human tumor cells. Our studies indicate that the CRISPR/Cas9 system can be effectively targeted to herpesvirus genomes as a potent prophylactic and therapeutic anti-viral strategy that may be used to impair viral replication and clear latent virus infection. PMID:27362483

  3. CRISPR/Cas9-Mediated Genome Editing of Herpesviruses Limits Productive and Latent Infections.

    PubMed

    van Diemen, Ferdy R; Kruse, Elisabeth M; Hooykaas, Marjolein J G; Bruggeling, Carlijn E; Schürch, Anita C; van Ham, Petra M; Imhof, Saskia M; Nijhuis, Monique; Wiertz, Emmanuel J H J; Lebbink, Robert Jan

    2016-06-01

    Herpesviruses infect the majority of the human population and can cause significant morbidity and mortality. Herpes simplex virus (HSV) type 1 causes cold sores and herpes simplex keratitis, whereas HSV-2 is responsible for genital herpes. Human cytomegalovirus (HCMV) is the most common viral cause of congenital defects and is responsible for serious disease in immuno-compromised individuals. Epstein-Barr virus (EBV) is associated with infectious mononucleosis and a broad range of malignancies, including Burkitt's lymphoma, nasopharyngeal carcinoma, Hodgkin's disease, and post-transplant lymphomas. Herpesviruses persist in their host for life by establishing a latent infection that is interrupted by periodic reactivation events during which replication occurs. Current antiviral drug treatments target the clinical manifestations of this productive stage, but they are ineffective at eliminating these viruses from the infected host. Here, we set out to combat both productive and latent herpesvirus infections by exploiting the CRISPR/Cas9 system to target viral genetic elements important for virus fitness. We show effective abrogation of HCMV and HSV-1 replication by targeting gRNAs to essential viral genes. Simultaneous targeting of HSV-1 with multiple gRNAs completely abolished the production of infectious particles from human cells. Using the same approach, EBV can be almost completely cleared from latently infected EBV-transformed human tumor cells. Our studies indicate that the CRISPR/Cas9 system can be effectively targeted to herpesvirus genomes as a potent prophylactic and therapeutic anti-viral strategy that may be used to impair viral replication and clear latent virus infection. PMID:27362483

  4. Sensing of latent EBV infection through exosomal transfer of 5'pppRNA.

    PubMed

    Baglio, S Rubina; van Eijndhoven, Monique A J; Koppers-Lalic, Danijela; Berenguer, Jordi; Lougheed, Sinéad M; Gibbs, Susan; Léveillé, Nicolas; Rinkel, Rico N P M; Hopmans, Erik S; Swaminathan, Sankar; Verkuijlen, Sandra A W M; Scheffer, George L; van Kuppeveld, Frank J M; de Gruijl, Tanja D; Bultink, Irene E M; Jordanova, Ekaterina S; Hackenberg, Michael; Piersma, Sander R; Knol, Jaco C; Voskuyl, Alexandre E; Wurdinger, Thomas; Jiménez, Connie R; Middeldorp, Jaap M; Pegtel, D Michiel

    2016-02-01

    Complex interactions between DNA herpesviruses and host factors determine the establishment of a life-long asymptomatic latent infection. The lymphotropic Epstein-Barr virus (EBV) seems to avoid recognition by innate sensors despite massive transcription of immunostimulatory small RNAs (EBV-EBERs). Here we demonstrate that in latently infected B cells, EBER1 transcripts interact with the lupus antigen (La) ribonucleoprotein, avoiding cytoplasmic RNA sensors. However, in coculture experiments we observed that latent-infected cells trigger antiviral immunity in dendritic cells (DCs) through selective release and transfer of RNA via exosomes. In ex vivo tonsillar cultures, we observed that EBER1-loaded exosomes are preferentially captured and internalized by human plasmacytoid DCs (pDCs) that express the TIM1 phosphatidylserine receptor, a known viral- and exosomal target. Using an EBER-deficient EBV strain, enzymatic removal of 5'ppp, in vitro transcripts, and coculture experiments, we established that 5'pppEBER1 transfer via exosomes drives antiviral immunity in nonpermissive DCs. Lupus erythematosus patients suffer from elevated EBV load and activated antiviral immunity, in particular in skin lesions that are infiltrated with pDCs. We detected high levels of EBER1 RNA in such skin lesions, as well as EBV-microRNAs, but no intact EBV-DNA, linking non-cell-autonomous EBER1 presence with skin inflammation in predisposed individuals. Collectively, our studies indicate that virus-modified exosomes have a physiological role in the host-pathogen stand-off and may promote inflammatory disease. PMID:26768848

  5. Diagnosis and Treatment of Latent Tuberculosis Infection in Healthcare Workers

    PubMed Central

    2016-01-01

    Tuberculosis (TB) is one of the most important occupational risks for healthcare workers (HCWs) in South Korea. Many policies regarding the control and prevention of TB in healthcare settings recommend that HCWs are tested for latent tuberculosis infection (LTBI) in addition to active TB. Moreover, the Korean Tuberculosis Prevention Act also recommends that HCWs receive regular testing for LTBI. However, there are no specific or detailed guidelines for dealing with LTBI in HCWs. Herein, we discuss the diagnosis and treatment of LTBI in HCWs and focus particularly on the baseline screening of hired HCWs, routine follow-up, and contact investigation. PMID:27433172

  6. CD4+ and CD8+ T-Cell Responses to Latent Antigen EBNA-1 and Lytic Antigen BZLF-1 during Persistent Lymphocryptovirus Infection of Rhesus Macaques

    PubMed Central

    Leskowitz, R. M.; Zhou, X. Y.; Villinger, F.; Fogg, M. H.; Kaur, A.; Lieberman, P. M.; Wang, F.

    2013-01-01

    Epstein-Barr virus (EBV) infection leads to lifelong viral persistence through its latency in B cells. EBV-specific T cells control reactivations and prevent the development of EBV-associated malignancies in most healthy carriers, but infection can sometimes cause chronic disease and malignant transformation. Epstein-Barr nuclear antigen 1 (EBNA-1) is the only viral protein consistently expressed during all forms of latency and in all EBV-associated malignancies and is a promising target for a therapeutic vaccine. Here, we studied the EBNA-1-specific immune response using the EBV-homologous rhesus lymphocryptovirus (rhLCV) infection in rhesus macaques. We assessed the frequency, phenotype, and cytokine production profiles of rhLCV EBNA-1 (rhEBNA-1)-specific T cells in 15 rhesus macaques and compared them to the lytic antigen of rhLCV BZLF-1 (rhBZLF-1). We were able to detect rhEBNA-1-specific CD4+ and/or CD8+ T cells in 14 of the 15 animals screened. In comparison, all 15 animals had detectable rhBZLF-1 responses. Most peptide-specific CD4+ T cells exhibited a resting phenotype of central memory (TCM), while peptide-specific CD8+ T cells showed a more activated phenotype, belonging mainly to the effector cell subset. By comparing our results to the human EBV immune response, we demonstrate that the rhLCV model is a valid system for studying chronic EBV infection and for the preclinical development of therapeutic vaccines. PMID:23698300

  7. Emphysematous lung destruction by cigarette smoke. The effects of latent adenoviral infection on the lung inflammatory response.

    PubMed

    Meshi, Bernard; Vitalis, Timothy Z; Ionescu, Diana; Elliott, W Mark; Liu, Chun; Wang, Xiang-Dong; Hayashi, Shizu; Hogg, James C

    2002-01-01

    This study was designed to test the hypothesis that cigarette smoke-induced inflammation and emphysema are amplified by the presence of latent adenoviral (Ad) infection, and to determine whether this emphysematous process can be reversed by all-trans-retinoic acid (RA) treatment. The results confirm that in guinea pigs, chronic cigarette-smoke exposure caused lesions similar to human centrilobular emphysema. They also show that latent Ad infection combined with cigarette-smoke exposure caused an excess increase in lung volume (P < 0.001), air-space volume (P < 0.001), and lung weight (P < 0.01), and further decrease in surface-to-volume ratio (P < 0.001) compared with smoke exposure alone. RA treatment failed to reverse these emphysematous changes. Analysis of inflammatory response in parenchymal and airway tissue showed that smoking caused an increase of polymorphonuclear leukocytes (PMNs) (P < 0.0002), macrophages (P < 0.001), and CD4 cells (P < 0.0009), and that latent Ad infection independently increased PMNs (P < 0.001), macrophages (P = 0.003), and CD8 cells (P < 0.001). We conclude that latent Ad infection amplifies the emphysematous lung destruction and increases the inflammatory response produced by cigarette-smoke exposure. In this study, the increase in CD4 was associated with cigarette smoke and the increase in CD8 cells with latent Ad infection. PMID:11751203

  8. Ocular and neural distribution of feline herpesvirus-1 during active and latent experimental infection in cats

    PubMed Central

    2013-01-01

    Background Herpes simplex virus 1 (HSV-1) and varicella zoster virus (VZV) cause extensive intra-ocular and neural infections in humans and are closely related to Felid herpes virus 1 (FeHV-1). We report the extent of intra-ocular replication and the extent and morphological aspects of neural replication during the acute and latent phases of FeHV-1 infection. Juvenile, SPF cats were inoculated with FeHV-1. Additional cats were used as negative controls. Cats were euthanized on days 6, 10, and 30 post-inoculation. Results FeHV-1 was isolated from the conjunctiva, cornea, uveal tract, retina, optic nerve, ciliary ganglion (CG), pterygopalatine ganglion (PTPG), trigeminal ganglion (TG), brainstem, visual cortex, cerebellum, and olfactory bulb of infected cats during the acute phase, but not the cranial cervical ganglion (CCG) and optic chiasm. Viral DNA was detected in all tissues during acute infection by a real-time quantitative PCR assay. On day 30, viral DNA was detected in all TG, all CCG, and 2 PTPG. Histologically mild inflammation and ganglion cell loss were noted within the TG during acute, but not latent infection. Using linear regression, a strong correlation existed between clinical score and day 30 viral DNA copy number within the TG. Conclusions The correlation between clinical score and day 30 viral DNA copy number suggests the severity of the acute clinical infection is related to the quantity of latent viral DNA. The histologic response was similar to that seen during HSV-1 or VZV infection. To the author’s knowledge this is the first report of FeHV-1 infection involving intraocular structures and autonomic ganglia. PMID:24053192

  9. Three Distinct Regions of the Murine Gammaherpesvirus 68 Genome Are Transcriptionally Active in Latently Infected Mice

    PubMed Central

    Virgin, Herbert W.; Presti, Rachel M.; Li, Xi-Yang; Liu, Carl; Speck, Samuel H.

    1999-01-01

    The program(s) of gene expression operating during murine gammaherpesvirus 68 (γHV68) latency is undefined, as is the relationship between γHV68 latency and latency of primate gammaherpesviruses. We used a nested reverse transcriptase PCR strategy (sensitive to approximately one copy of γHV68 genome for each genomic region tested) to screen for the presence of viral transcripts in latently infected mice. Based on the positions of known latency-associated genes in other gammaherpesviruses, we screened for the presence of transcripts corresponding to 11 open reading frames (ORFs) in the γHV68 genome in RNA from spleens and peritoneal cells of latently infected B-cell-deficient (MuMT) mice which have been shown contain high levels of reactivable latent γHV68 (K. E. Weck, M. L. Barkon, L. I. Yoo, S. H. Speck, and H. W. Virgin, J. Virol. 70:6775–6780, 1996). To control for the possible presence of viral lytic activity, we determined that RNA from latently infected peritoneal and spleen cells contained few or no detectable transcripts corresponding to seven ORFs known to encode viral gene products associated with lytic replication. However, we did detect low-level expression of transcripts arising from the region of gene 50 (encoding the putative homolog of the Epstein-Barr virus BRLF1 transactivator) in peritoneal but not spleen cells. Latently infected peritoneal cells consistently scored for expression of RNA derived from 4 of the 11 candidate latency-associated ORFs examined, including the regions of ORF M2, ORF M11 (encoding v-bcl-2), gene 73 (a homolog of the Kaposi’s sarcoma-associated herpesvirus [human herpesvirus 8] gene encoding latency-associated nuclear antigen), and gene 74 (encoding a G-protein coupled receptor homolog, v-GCR). Latently infected spleen cells consistently scored positive for RNA derived from 3 of the 11 candidate latency-associated ORFs examined, including ORF M2, ORF M3, and ORF M9. To further characterize transcription of these

  10. Latent virus infection upregulates CD40 expression facilitating enhanced autoimmunity in a model of multiple sclerosis

    PubMed Central

    Casiraghi, Costanza; Citlali Márquez, Ana; Shanina, Iryna; Steven Horwitz, Marc

    2015-01-01

    Epstein-Barr virus (EBV) has been identified as a putative environmental trigger of multiple sclerosis (MS) by multiple groups working worldwide. Previously, we reported that when experimental autoimmune encephalomyelitis (EAE) was induced in mice latently infected with murine γ-herpesvirus 68 (γHV-68), the murine homolog to EBV, a disease more reminiscent of MS developed. Specifically, MS-like lesions developed in the brain that included equal numbers of IFN-γ producing CD4+ and CD8+ T cells and demyelination, none of which is observed in MOG induced EAE. Herein, we demonstrate that this enhanced disease was dependent on the γHV-68 latent life cycle and was associated with STAT1 and CD40 upregulation on uninfected dendritic cells. Importantly, we also show that, during viral latency, the frequency of regulatory T cells is reduced via a CD40 dependent mechanism and this contributes towards a strong T helper 1 response that resolves in severe EAE disease pathology. Latent γ-herpesvirus infection established a long-lasting impact that enhances subsequent adaptive autoimmune responses. PMID:26356194

  11. A fifth Epstein-Barr virus nuclear protein (EBNA3C) is expressed in latently infected growth-transformed lymphocytes.

    PubMed Central

    Petti, L; Sample, J; Wang, F; Kieff, E

    1988-01-01

    Three distantly homologous neighboring long open reading frames in the Epstein-Barr virus (EBV) genome are preceded by short open reading frames. The leftmost short and long open reading frames encode EBNA3, a nuclear protein which is slightly smaller (145 kilodaltons [kDa]) than two other nuclear proteins (150 to 155 kDa) detected in Western blots (immunoblots) of latently infected cell protein (K. Hennessy, F. Wang, E. Woodland-Bushman, and E. Kieff, Proc. Natl. Acad. Sci. USA 83:5693-5697, 1986; I. Joab, D. T. Rowe, M. Bodescot, J.-C. Nicolas, P. J. Farrell, and M. Perricaudet, J. Virol. 61:3340-3344, 1987). We have demonstrated that the most rightward short (BERF3) and long (BERF4) open reading frames are spliced in frame at the 3' end of a 5-kilobase latently infected cell RNA and that this RNA begins within or upstream of the EBV long internal repeat. EBV-immune human antibodies specific for the long open reading frame translation product identified a 155-kDa protein on Western blots of latently infected cell protein and specifically reacted with large nonnucleolar nuclear granules in every latently infected cell. Expression of the cDNA in BALB/c 3T3 cells resulted in translation of full-size EBNA3C but had no effect on cell morphology, contact inhibition, or serum independence. Images PMID:2831394

  12. Pulmonary responses to pathogen-specific antigens in latent Mycobacterium tuberculosis infection.

    PubMed

    Jarvela, Jessica R; Tuscano, Lori; Lee, Hung; Silver, Richard F

    2016-01-01

    In this study, we used ELISPOT to quantify frequencies of bronchoalveolar lavage (BAL) and peripheral blood T cells capable of producing IFNγ in response to PPD, antigen 85B, and Mtb-specific antigens CFP-10 and ESAT-6 in individuals with latent tuberculosis infection (LTBI) and Mtb-naïve controls. Compared to peripheral blood, BAL cells of LTBI subjects displayed significant enrichment for T cells responding to PPD, antigen 85B, and CFP-10, but not to ESAT-6. Baseline BAL cells of LTBI subjects displayed significant production of Mig (CXCL9) in response to PPD, antigen 85B, and CFP-10 as well. These findings suggest that enrichment for Mtb-specific T cells within BAL is not unique to active pulmonary tuberculosis and may, to the contrary, contribute to protection from re-infection in Mtb immune individuals. PMID:26732045

  13. Amplification of inflammation in emphysema and its association with latent adenoviral infection.

    PubMed

    Retamales, I; Elliott, W M; Meshi, B; Coxson, H O; Pare, P D; Sciurba, F C; Rogers, R M; Hayashi, S; Hogg, J C

    2001-08-01

    This study examines the hypothesis that the cigarette smoke-induced inflammatory process is amplified in severe emphysema and explores the association of this response with latent adenoviral infection. Lung tissue from patients with similar smoking histories and either no (n = 7), mild (n = 7), or severe emphysema (n = 7) was obtained by lung resection. Numbers of polymorphonuclear cells (PMN), macrophages, B cells, CD4, CD8 lymphocytes, and eosinophils present in tissue and airspaces and of epithelial cells expressing adenoviral E1A protein were determined using quantitative techniques. Severe emphysema was associated with an absolute increase in the total number of inflammatory cells in the lung tissue and airspaces. The computed tomography (CT) determined extent of lung destruction was related to the number of cells/m(2) surface area by R(2) values that ranged from 0.858 (CD8 cells) to 0.483 (B cells) in the tissue and 0.630 (CD4 cells) to 0.198 (B cells) in the airspaces. These changes were associated with a 5- to 40-fold increase in the number of alveolar epithelial cells expressing adenoviral E1A protein in mild and severe disease, respectively. We conclude that cigarette smoke-induced lung inflammation is amplified in severe emphysema and that latent expression of the adenoviral E1A protein expressed by alveolar epithelial cells influenced this amplification process. PMID:11500352

  14. Kaposi's Sarcoma-Associated Herpesvirus Latency-Associated Nuclear Antigen and Angiogenin Interact with Common Host Proteins, Including Annexin A2, Which Is Essential for Survival of Latently Infected Cells

    PubMed Central

    Paudel, Nitika; Sadagopan, Sathish; Balasubramanian, Sandhya

    2012-01-01

    Kaposi's sarcoma-associated herpesvirus (KSHV) infection and latency-associated nuclear antigen (LANA-1) upregulate the multifunctional protein angiogenin (ANG). Our studies demonstrate that silencing ANG or inhibiting its nuclear translocation downregulates KSHV LANA-1 expression and ANG is necessary for KSHV latency, anti-apoptosis and angiogenesis (Sadagopan et al., J. Virol. 83:3342–3364, 2009; Sadagopan et al., J Virol. 85:2666–2685, 2011). Here we show that LANA-1 interacts with ANG and colocalizes in latently infected endothelial telomerase-immortalized human umbilical vein endothelial (TIVE-LTC) cells. Mass spectrometric analyses of TIVE-LTC proteins immunoprecipitated by anti-LANA-1 and ANG antibodies identified 28 common cellular proteins such as ribosomal proteins, structural proteins, tRNA synthetases, metabolic pathway enzymes, chaperons, transcription factors, antioxidants, and ubiquitin proteosome proteins. LANA-1 and ANG interaction with one of the proteins, annexin A2, was validated. Annexin A2 has been shown to play roles in cell proliferation, apoptosis, plasmin generation, exocytosis, endocytosis, and cytoskeleton reorganization. It is also known to associate with glycolytic enzyme 3-phosphoglyceratekinase in the primer recognition protein (PRP) complex that interacts with DNA polymerase α in the lagging strand of DNA during replication. A higher level of annexin A2 is expressed in KSHV+ but not in Epstein-Barr virus (EBV)+ B-lymphoma cell lines. Annexin A2 colocalized with several LANA-1 punctate spots in KSHV+ body cavity B-cell lymphoma (BCBL-1) cells. In triple-staining analyses, we observed annexin A2-ANG-LANA-1, annexin A2-ANG, and ANG-LANA-1 colocalizations. Annexin A2 appeared as punctate nuclear dots in LANA-1-positive TIVE-LTC cells. In LANA-1-negative TIVE-LTC cells, annexin A2 was detected predominately in the cytoplasm, with some nuclear spots, and colocalization with ANG was observed mostly in the cytoplasm. Annexin A2

  15. Sensing of latent EBV infection through exosomal transfer of 5′pppRNA

    PubMed Central

    Baglio, S. Rubina; van Eijndhoven, Monique A. J.; Koppers-Lalic, Danijela; Berenguer, Jordi; Lougheed, Sinéad M.; Gibbs, Susan; Léveillé, Nicolas; Rinkel, Rico N. P. M.; Hopmans, Erik S.; Swaminathan, Sankar; Verkuijlen, Sandra A. W. M.; Scheffer, George L.; van Kuppeveld, Frank J. M.; de Gruijl, Tanja D.; Bultink, Irene E. M.; Jordanova, Ekaterina S.; Hackenberg, Michael; Piersma, Sander R.; Knol, Jaco C.; Voskuyl, Alexandre E.; Wurdinger, Thomas; Jiménez, Connie R.; Middeldorp, Jaap M.; Pegtel, D. Michiel

    2016-01-01

    Complex interactions between DNA herpesviruses and host factors determine the establishment of a life-long asymptomatic latent infection. The lymphotropic Epstein–Barr virus (EBV) seems to avoid recognition by innate sensors despite massive transcription of immunostimulatory small RNAs (EBV-EBERs). Here we demonstrate that in latently infected B cells, EBER1 transcripts interact with the lupus antigen (La) ribonucleoprotein, avoiding cytoplasmic RNA sensors. However, in coculture experiments we observed that latent-infected cells trigger antiviral immunity in dendritic cells (DCs) through selective release and transfer of RNA via exosomes. In ex vivo tonsillar cultures, we observed that EBER1-loaded exosomes are preferentially captured and internalized by human plasmacytoid DCs (pDCs) that express the TIM1 phosphatidylserine receptor, a known viral- and exosomal target. Using an EBER-deficient EBV strain, enzymatic removal of 5′ppp, in vitro transcripts, and coculture experiments, we established that 5′pppEBER1 transfer via exosomes drives antiviral immunity in nonpermissive DCs. Lupus erythematosus patients suffer from elevated EBV load and activated antiviral immunity, in particular in skin lesions that are infiltrated with pDCs. We detected high levels of EBER1 RNA in such skin lesions, as well as EBV-microRNAs, but no intact EBV-DNA, linking non–cell-autonomous EBER1 presence with skin inflammation in predisposed individuals. Collectively, our studies indicate that virus-modified exosomes have a physiological role in the host–pathogen stand-off and may promote inflammatory disease. PMID:26768848

  16. Characterisation of DNA forms associated with cassava latent virus infection.

    PubMed Central

    Stanley, J; Townsend, R

    1985-01-01

    In addition to the major encapsidated DNA species found in preparations of cassava latent virus (genomic DNAs 1 and 2) there are minor DNA populations of twice (dimeric) and approximately half genome length. Both minor species resemble the genomic DNAs in that they are composed of predominantly circular single-stranded DNA. All of these size groups have a corresponding covalently-closed circular double-stranded DNA form in infected tissue. Infectivity studies using cloned DNAs 1 and 2 show that dimeric DNA routinely appears, suggesting it to be an intermediate in the DNA replicative cycle that can be encapsidated at low efficiency. In contrast, half unit length DNA has not yet been detected after multiple passaging of virus derived from the cloned DNA inoculum. Half unit length DNAs appear to be derived exclusively from DNA 2 and consist of a population of molecules exhibiting a relatively specific deletion. As they have an inhibitory effect on virus multiplication, their encapsidated forms are analogous to defective interfering particles associated with other eukaryotic DNA containing viruses. Small primer molecules associated with the genomic single-stranded DNAs, as reported for another geminivirus, have not been detected in CLV. Images PMID:4000956

  17. Latent Tuberculosis Infection and the Risk of Subsequent Cancer.

    PubMed

    Su, Vincent Yi-Fong; Yen, Yung-Feng; Pan, Sheng-Wei; Chuang, Pei-Hung; Feng, Jia-Yih; Chou, Kun-Ta; Chen, Yuh-Min; Chen, Tzeng-Ji; Su, Wei-Juin

    2016-01-01

    The association of latent tuberculosis infection (LTBI) with subsequent cancer remains unclear. We investigated the risk of future cancer among tuberculosis (TB) contacts with or without subsequent TB activation. Using the Taiwan National Health Insurance Research Database, we conducted a nationwide population-based study. TB contacts during 1997 to 2012 were included as the study cohort. Patients with antecedent cancer and TB were excluded. Data from 11,522 TB contacts and 46,088 age-, sex-, and enrollment date-matched subjects during 1997 to 2012 were analyzed. The 2 cohorts were monitored until December 31, 2012 for incidence of cancer and TB infection. LTBI was defined as a TB contact with subsequent TB activation. The primary endpoint was occurrence of newly diagnosed cancer. There was no difference in cancer development between the TB contact cohort and comparison cohort (log-rank test, P = 0.714). After multivariate adjustment, the hazard ratio (HR) for cancer among the LTBI patients was 2.29 [95% confidence interval (CI), 1.26-4.17; P = 0.007]. There was increase in cancer incidences for several specific cancer types, including multiple myeloma (HR 340.28), lung (HR 2.69), kidney and bladder (HR 6.16), hepatobiliary (HR 2.36), and gastrointestinal (HR 2.99) cancers. None of the 136 TB contacts who received isoniazid prophylaxis developed cancer. LTBI patients had a higher risk of future cancer. PMID:26825880

  18. Monitoring latent tuberculosis infection diagnosis and management in the Netherlands.

    PubMed

    Erkens, Connie G M; Slump, Erika; Verhagen, Maurits; Schimmel, Henrieke; de Vries, Gerard; Cobelens, Frank; van den Hof, Susan

    2016-05-01

    Targeted diagnosis and treatment of latent tuberculosis (TB) infection (LTBI) among persons with a high risk of exposure to TB or of developing TB when infected has been performed and monitored routinely in the Netherlands since 1993. We describe trends in target groups, diagnostic methods and treatment regimens, and explore determinants for treatment initiation, treatment completion and adverse events.In total, 37 729 persons were registered with LTBI from 1993 to 2013, of whom 28 931 (77%) started preventive treatment; 82% of those completed preventive treatment and 8% stopped preventive treatment due to adverse events. Two-thirds of the notified cases were detected through contact investigation.Increasing numbers of persons with immunosuppressive disorders, elderly persons and foreign-born persons were notified in recent years, due to policy changes and the introduction of the interferon-γ release assay. Children (96%) and the immunosuppressed (95%) were more likely to start preventive treatment. Children (93%) were also more likely to complete preventive treatment, as were persons treated with rifampicin or rifampicin/isoniazid regimens (91% and 92%, respectively). The latter groups were also 40% less likely to stop preventive treatment due to adverse events.Under these operational conditions, the estimated risk reduction on incident TB in the target population for LTBI management is 40-60%. PMID:26917614

  19. Latent Herpes Simplex Virus Infection of Sensory Neurons Alters Neuronal Gene Expression

    PubMed Central

    Kramer, Martha F.; Cook, W. James; Roth, Frederick P.; Zhu, Jia; Holman, Holly; Knipe, David M.; Coen, Donald M.

    2003-01-01

    The persistence of herpes simplex virus (HSV) and the diseases that it causes in the human population can be attributed to the maintenance of a latent infection within neurons in sensory ganglia. Little is known about the effects of latent infection on the host neuron. We have addressed the question of whether latent HSV infection affects neuronal gene expression by using microarray transcript profiling of host gene expression in ganglia from latently infected versus mock-infected mouse trigeminal ganglia. 33P-labeled cDNA probes from pooled ganglia harvested at 30 days postinfection or post-mock infection were hybridized to nylon arrays printed with 2,556 mouse genes. Signal intensities were acquired by phosphorimager. Mean intensities (n = 4 replicates in each of three independent experiments) of signals from mock-infected versus latently infected ganglia were compared by using a variant of Student's t test. We identified significant changes in the expression of mouse neuronal genes, including several with roles in gene expression, such as the Clk2 gene, and neurotransmission, such as genes encoding potassium voltage-gated channels and a muscarinic acetylcholine receptor. We confirmed the neuronal localization of some of these transcripts by using in situ hybridization. To validate the microarray results, we performed real-time reverse transcriptase PCR analyses for a selection of the genes. These studies demonstrate that latent HSV infection can alter neuronal gene expression and might provide a new mechanism for how persistent viral infection can cause chronic disease. PMID:12915567

  20. Kinase Control of Latent HIV-1 Infection: PIM-1 Kinase as a Major Contributor to HIV-1 Reactivation

    PubMed Central

    Duverger, Alexandra; Wolschendorf, Frank; Anderson, Joshua C.; Wagner, Frederic; Bosque, Alberto; Shishido, Takao; Jones, Jennifer; Planelles, Vicente; Willey, Christopher; Cron, Randall Q.

    2014-01-01

    Despite the clinical relevance of latent HIV-1 infection as a block to HIV-1 eradication, the molecular biology of HIV-1 latency remains incompletely understood. We recently demonstrated the presence of a gatekeeper kinase function that controls latent HIV-1 infection. Using kinase array analysis, we here expand on this finding and demonstrate that the kinase activity profile of latently HIV-1-infected T cells is altered relative to that of uninfected T cells. A ranking of altered kinases generated from these kinome profile data predicted PIM-1 kinase as a key switch involved in HIV-1 latency control. Using genetic and pharmacologic perturbation strategies, we demonstrate that PIM-1 activity is indeed required for HIV-1 reactivation in T cell lines and primary CD4 T cells. The presented results thus confirm that kinases are key contributors to HIV-1 latency control. In addition, through mutational studies we link the inhibitory effect of PIM-1 inhibitor IV (PIMi IV) on HIV-1 reactivation to an AP-1 motif in the CD28-responsive element of the HIV-1 long terminal repeat (LTR). The results expand our conceptual understanding of the dynamic interactions of the host cell and the latent HIV-1 integration event and position kinome profiling as a research tool to reveal novel molecular mechanisms that can eventually be targeted to therapeutically trigger HIV-1 reactivation. PMID:24155393

  1. Kinase control of latent HIV-1 infection: PIM-1 kinase as a major contributor to HIV-1 reactivation.

    PubMed

    Duverger, Alexandra; Wolschendorf, Frank; Anderson, Joshua C; Wagner, Frederic; Bosque, Alberto; Shishido, Takao; Jones, Jennifer; Planelles, Vicente; Willey, Christopher; Cron, Randall Q; Kutsch, Olaf

    2014-01-01

    Despite the clinical relevance of latent HIV-1 infection as a block to HIV-1 eradication, the molecular biology of HIV-1 latency remains incompletely understood. We recently demonstrated the presence of a gatekeeper kinase function that controls latent HIV-1 infection. Using kinase array analysis, we here expand on this finding and demonstrate that the kinase activity profile of latently HIV-1-infected T cells is altered relative to that of uninfected T cells. A ranking of altered kinases generated from these kinome profile data predicted PIM-1 kinase as a key switch involved in HIV-1 latency control. Using genetic and pharmacologic perturbation strategies, we demonstrate that PIM-1 activity is indeed required for HIV-1 reactivation in T cell lines and primary CD4 T cells. The presented results thus confirm that kinases are key contributors to HIV-1 latency control. In addition, through mutational studies we link the inhibitory effect of PIM-1 inhibitor IV (PIMi IV) on HIV-1 reactivation to an AP-1 motif in the CD28-responsive element of the HIV-1 long terminal repeat (LTR). The results expand our conceptual understanding of the dynamic interactions of the host cell and the latent HIV-1 integration event and position kinome profiling as a research tool to reveal novel molecular mechanisms that can eventually be targeted to therapeutically trigger HIV-1 reactivation. PMID:24155393

  2. A Mycobacterium tuberculosis Dormancy Antigen Differentiates Latently Infected Bacillus Calmette–Guérin-vaccinated Individuals

    PubMed Central

    Peña, Delfina; Rovetta, Ana I.; Hernández Del Pino, Rodrigo E.; Amiano, Nicolás O.; Pasquinelli, Virginia; Pellegrini, Joaquín M.; Tateosian, Nancy L.; Rolandelli, Agustín; Gutierrez, Marisa; Musella, Rosa M.; Palmero, Domingo J.; Gherardi, María M.; Iovanna, Juan; Chuluyan, H. Eduardo; García, Verónica E.

    2015-01-01

    IFN-γ release assays (IGRAs) are better indicators of Mycobacterium tuberculosis infection than the tuberculin skin test (TST) in Bacillus Calmette–Guérin (BCG)-vaccinated populations. However, IGRAs do not discriminate active and latent infections (LTBI) and no gold standard for LTBI diagnosis is available. Thus, since improved tests to diagnose M. tuberculosis infection are required, we assessed the efficacy of several M. tuberculosis latency antigens. BCG-vaccinated healthy donors (HD) and tuberculosis (TB) patients were recruited. QuantiFERON-TB Gold In-Tube, TST and clinical data were used to differentiate LTBI. IFN-γ production against CFP-10, ESAT-6, Rv2624c, Rv2626c and Rv2628 antigens was tested in peripheral blood mononuclear cells. LTBI subjects secreted significantly higher IFN-γ levels against Rv2626c than HD. Additionally, Rv2626c peptide pools to which only LTBI responded were identified, and their cumulative IFN-γ response improved LTBI discrimination. Interestingly, whole blood stimulation with Rv2626c allowed the discrimination between active and latent infections, since TB patients did not secrete IFN-γ against Rv2626c, in contrast to CFP-10 + ESAT-6 stimulation that induced IFN-γ response from both LTBI and TB patients. ROC analysis confirmed that Rv2626c discriminated LTBI from HD and TB patients. Therefore, since only LTBI recognizes specific epitopes from Rv2626c, this antigen could improve LTBI diagnosis, even in BCG-vaccinated people. PMID:26425695

  3. A Mycobacterium tuberculosis Dormancy Antigen Differentiates Latently Infected Bacillus Calmette-Guérin-vaccinated Individuals.

    PubMed

    Peña, Delfina; Rovetta, Ana I; Hernández Del Pino, Rodrigo E; Amiano, Nicolás O; Pasquinelli, Virginia; Pellegrini, Joaquín M; Tateosian, Nancy L; Rolandelli, Agustín; Gutierrez, Marisa; Musella, Rosa M; Palmero, Domingo J; Gherardi, María M; Iovanna, Juan; Chuluyan, H Eduardo; García, Verónica E

    2015-08-01

    IFN-γ release assays (IGRAs) are better indicators of Mycobacterium tuberculosis infection than the tuberculin skin test (TST) in Bacillus Calmette-Guérin (BCG)-vaccinated populations. However, IGRAs do not discriminate active and latent infections (LTBI) and no gold standard for LTBI diagnosis is available. Thus, since improved tests to diagnose M. tuberculosis infection are required, we assessed the efficacy of several M. tuberculosis latency antigens. BCG-vaccinated healthy donors (HD) and tuberculosis (TB) patients were recruited. QuantiFERON-TB Gold In-Tube, TST and clinical data were used to differentiate LTBI. IFN-γ production against CFP-10, ESAT-6, Rv2624c, Rv2626c and Rv2628 antigens was tested in peripheral blood mononuclear cells. LTBI subjects secreted significantly higher IFN-γ levels against Rv2626c than HD. Additionally, Rv2626c peptide pools to which only LTBI responded were identified, and their cumulative IFN-γ response improved LTBI discrimination. Interestingly, whole blood stimulation with Rv2626c allowed the discrimination between active and latent infections, since TB patients did not secrete IFN-γ against Rv2626c, in contrast to CFP-10 + ESAT-6 stimulation that induced IFN-γ response from both LTBI and TB patients. ROC analysis confirmed that Rv2626c discriminated LTBI from HD and TB patients. Therefore, since only LTBI recognizes specific epitopes from Rv2626c, this antigen could improve LTBI diagnosis, even in BCG-vaccinated people. PMID:26425695

  4. A Mouse Model of Latent Tuberculosis Infection to Study Intervention Strategies to Prevent Reactivation.

    PubMed

    Kupz, Andreas; Zedler, Ulrike; Stäber, Manuela; Kaufmann, Stefan H E

    2016-01-01

    Infection with Mycobacterium tuberculosis (Mtb) is the leading cause of death in human immunodeficiency virus (HIV)+ individuals, particularly in Sub-Saharan Africa. Management of this deadly co-infection is a significant global health challenge that is exacerbated by the lack of efficient vaccines against both Mtb and HIV, as well as the lack of reliable and robust animal models for Mtb/HIV co-infection. Here we describe a tractable and reproducible mouse model to study the reactivation dynamics of latent Mtb infection following the loss of CD4+ T cells as it occurs in HIV-co-infected individuals. Whereas intradermally (i.d.) infected C57BL/6 mice contained Mtb within the local draining lymph nodes, depletion of CD4+ cells led to progressive systemic spread of the bacteria and induction of lung pathology. To interrogate whether reactivation of Mtb after CD4+ T cell depletion can be reversed, we employed interleukin (IL)-2/anti-IL-2 complex-mediated cell boost approaches. Although populations of non-CD4 lymphocytes, such as CD8+ memory T cells, natural killer (NK) cells and double-negative (DN) T cells significantly expanded after IL-2/anti-IL-2 complex treatment, progressive development of bacteremia and pathologic lung alterations could not be prevented. These data suggest that the failure to reverse Mtb reactivation is likely not due to anergy of the expanded cell subsets and rather indicates a limited potential for IL-2-complex-based therapies in the management of Mtb/HIV co-infection. PMID:27391012

  5. A Mouse Model of Latent Tuberculosis Infection to Study Intervention Strategies to Prevent Reactivation

    PubMed Central

    Kupz, Andreas; Zedler, Ulrike; Stäber, Manuela

    2016-01-01

    Infection with Mycobacterium tuberculosis (Mtb) is the leading cause of death in human immunodeficiency virus (HIV)+ individuals, particularly in Sub-Saharan Africa. Management of this deadly co-infection is a significant global health challenge that is exacerbated by the lack of efficient vaccines against both Mtb and HIV, as well as the lack of reliable and robust animal models for Mtb/HIV co-infection. Here we describe a tractable and reproducible mouse model to study the reactivation dynamics of latent Mtb infection following the loss of CD4+ T cells as it occurs in HIV-co-infected individuals. Whereas intradermally (i.d.) infected C57BL/6 mice contained Mtb within the local draining lymph nodes, depletion of CD4+ cells led to progressive systemic spread of the bacteria and induction of lung pathology. To interrogate whether reactivation of Mtb after CD4+ T cell depletion can be reversed, we employed interleukin (IL)-2/anti-IL-2 complex-mediated cell boost approaches. Although populations of non-CD4 lymphocytes, such as CD8+ memory T cells, natural killer (NK) cells and double-negative (DN) T cells significantly expanded after IL-2/anti-IL-2 complex treatment, progressive development of bacteremia and pathologic lung alterations could not be prevented. These data suggest that the failure to reverse Mtb reactivation is likely not due to anergy of the expanded cell subsets and rather indicates a limited potential for IL-2-complex-based therapies in the management of Mtb/HIV co-infection. PMID:27391012

  6. Complete Genome Sequence of a Hop Latent Virus Infecting Hop Plants

    PubMed Central

    Jo, Yeonhwa; Choi, Hoseong

    2015-01-01

    The hop latent virus is a single-stranded RNA virus that mainly infects hop plants. Here, we report the complete genome sequence of a hop latent virus, which was de novo assembled by RNA sequencing (RNA-seq). Our study indicates that transcriptome data are useful for identifying a complete viral genome. PMID:25908127

  7. Screening Optimization of Latent Tuberculosis Infection in Rheumatoid Arthritis Patients

    PubMed Central

    Mehta, Bella; Zapantis, Ekaterini; Petryna, Olga; Efthimiou, Petros

    2015-01-01

    Objective. Rheumatoid arthritis (RA) patients are at increased risk of latent tuberculosis infection (LTBI) but there are no clear guidelines for LTBI screening with Tuberculin Skin Test (TST) or Quantiferon TB Gold testing (QFT-G). Methods. A retrospective study was conducted in a high risk, largely foreign-born, inner city, RA population. After screening 280 RA patients, 134 patients who had both TST and QFT-G testing performed during their initial evaluation were included. Results. Out of 132 RA patients included in our analysis, 50 (37.8%) patients were diagnosed with LTBI with either positive TST 42 (31.8%) or QFT-G 23 (17.4%). 15 (11.4%) were positive and 82 (62.1%) were negative for both tests. The agreement between TST and QFT-G was 73.5% (Kappa 0.305, CI = 95% 0.147–0.463, p = 0.081).  Conclusions. There was low-moderate agreement (κ = 0.305) between TST and QFT-G. In the absence of clearly defined gold standard and limitations associated with both tests, we propose early screening with both tests for patients who need prompt treatment with BRMs. Patients who are not immediate candidates for BRM treatment may be safely and cost effectively screened with a two-step process: initial screening with TST and if negative, IGRA testing. Patients positive for either test should be promptly treated. PMID:26294972

  8. Genes Expressed in Grapevine Leaves Reveal Latent Wood Infection by the Fungal Pathogen Neofusicoccum parvum

    PubMed Central

    Czemmel, Stefan; Galarneau, Erin R.; Travadon, Renaud; McElrone, Andrew J.; Cramer, Grant R.; Baumgartner, Kendra

    2015-01-01

    Some pathogenic species of the Botryosphaeriaceae have a latent phase, colonizing woody tissues while perennial hosts show no apparent symptoms until conditions for disease development become favorable. Detection of these pathogens is often limited to the later pathogenic phase. The latent phase is poorly characterized, despite the need for non-destructive detection tools and effective quarantine strategies, which would benefit from identification of host-based markers in leaves. Neofusicoccum parvum infects the wood of grapevines and other horticultural crops, killing the fruit-bearing shoots. We used light microscopy and high-resolution computed tomography (HRCT) to examine the spatio-temporal relationship between pathogen colonization and anatomical changes in stem sections. To identify differentially-expressed grape genes, leaves from inoculated and non-inoculated plants were examined using RNA-Seq. The latent phase occurred between 0 and 1.5 months post-inoculation (MPI), during which time the pathogen did not spread significantly beyond the inoculation site nor were there differences in lesion lengths between inoculated and non-inoculated plants. The pathogenic phase occurred between 1.5 and 2 MPI, when recovery beyond the inoculation site increased and lesion lengths of inoculated plants tripled. By 2 MPI, inoculated plants also had decreased starch content in xylem fibers and rays, and increased levels of gel-occluded xylem vessels, the latter of which HRCT revealed at a higher frequency than microscopy. RNA-Seq and screening of 21 grape expression datasets identified 20 candidate genes that were transcriptionally-activated by infection during the latent phase, and confirmed that the four best candidates (galactinol synthase, abscisic acid-induced wheat plasma membrane polypeptide-19 ortholog, embryonic cell protein 63, BURP domain-containing protein) were not affected by a range of common foliar and wood pathogens or abiotic stresses. Assuming such host

  9. Genes expressed in grapevine leaves reveal latent wood infection by the fungal pathogen Neofusicoccum parvum.

    PubMed

    Czemmel, Stefan; Galarneau, Erin R; Travadon, Renaud; McElrone, Andrew J; Cramer, Grant R; Baumgartner, Kendra

    2015-01-01

    Some pathogenic species of the Botryosphaeriaceae have a latent phase, colonizing woody tissues while perennial hosts show no apparent symptoms until conditions for disease development become favorable. Detection of these pathogens is often limited to the later pathogenic phase. The latent phase is poorly characterized, despite the need for non-destructive detection tools and effective quarantine strategies, which would benefit from identification of host-based markers in leaves. Neofusicoccum parvum infects the wood of grapevines and other horticultural crops, killing the fruit-bearing shoots. We used light microscopy and high-resolution computed tomography (HRCT) to examine the spatio-temporal relationship between pathogen colonization and anatomical changes in stem sections. To identify differentially-expressed grape genes, leaves from inoculated and non-inoculated plants were examined using RNA-Seq. The latent phase occurred between 0 and 1.5 months post-inoculation (MPI), during which time the pathogen did not spread significantly beyond the inoculation site nor were there differences in lesion lengths between inoculated and non-inoculated plants. The pathogenic phase occurred between 1.5 and 2 MPI, when recovery beyond the inoculation site increased and lesion lengths of inoculated plants tripled. By 2 MPI, inoculated plants also had decreased starch content in xylem fibers and rays, and increased levels of gel-occluded xylem vessels, the latter of which HRCT revealed at a higher frequency than microscopy. RNA-Seq and screening of 21 grape expression datasets identified 20 candidate genes that were transcriptionally-activated by infection during the latent phase, and confirmed that the four best candidates (galactinol synthase, abscisic acid-induced wheat plasma membrane polypeptide-19 ortholog, embryonic cell protein 63, BURP domain-containing protein) were not affected by a range of common foliar and wood pathogens or abiotic stresses. Assuming such host

  10. Rapid Detection of Cyprinid Herpesvirus 3 in Latently Infected Koi by Recombinase Polymerase Amplification.

    PubMed

    Prescott, Meagan A; Reed, Aimee N; Jin, Ling; Pastey, Manoj K

    2016-09-01

    Since the emergence of cyprinid herpesvirus 3 (CyHV-3), outbreaks have been devastating to Common Carp Cyprinus carpio and koi (a variant of Common Carp), leading to high economic losses. Current diagnostics for detecting CyHV-3 are limited in sensitivity and are further complicated by latency. Here we describe the detection of CyHV-3 by recombinase polymerase amplification (RPA). The RPA assay can detect as low as 10 copies of the CyHV-3 genome by an isothermal reaction and yields results in approximately 20 min. Using the RPA assay, the CyHV-3 genome can be detected in the total DNA of white blood cells isolated from koi latently infected with CyHV-3, while less than 10% of the latently infected koi can be detected by a real-time PCR assay in the total DNA of white blood cells. In addition, RPA products can be detected in a lateral flow device that is cheap and fast and can be used outside of the diagnostic lab. The RPA assay and lateral flow device provide for the rapid, sensitive, and specific amplification of CyHV-3 that with future modifications for field use and validation could lead to enhanced surveillance and early diagnosis of CyHV-3 in the laboratory and field. Received September 14, 2015; accepted April 9, 2016. PMID:27485254

  11. The HSV-1 Latency-Associated Transcript Functions to Repress Latent Phase Lytic Gene Expression and Suppress Virus Reactivation from Latently Infected Neurons.

    PubMed

    Nicoll, Michael P; Hann, William; Shivkumar, Maitreyi; Harman, Laura E R; Connor, Viv; Coleman, Heather M; Proença, João T; Efstathiou, Stacey

    2016-04-01

    Herpes simplex virus 1 (HSV-1) establishes life-long latent infection within sensory neurons, during which viral lytic gene expression is silenced. The only highly expressed viral gene product during latent infection is the latency-associated transcript (LAT), a non-protein coding RNA that has been strongly implicated in the epigenetic regulation of HSV-1 gene expression. We have investigated LAT-mediated control of latent gene expression using chromatin immunoprecipitation analyses and LAT-negative viruses engineered to express firefly luciferase or β-galactosidase from a heterologous lytic promoter. Whilst we were unable to determine a significant effect of LAT expression upon heterochromatin enrichment on latent HSV-1 genomes, we show that reporter gene expression from latent HSV-1 genomes occurs at a greater frequency in the absence of LAT. Furthermore, using luciferase reporter viruses we have observed that HSV-1 gene expression decreases during long-term latent infection, with a most marked effect during LAT-negative virus infection. Finally, using a fluorescent mouse model of infection to isolate and culture single latently infected neurons, we also show that reactivation occurs at a greater frequency from cultures harbouring LAT-negative HSV-1. Together, our data suggest that the HSV-1 LAT RNA represses HSV-1 gene expression in small populations of neurons within the mouse TG, a phenomenon that directly impacts upon the frequency of reactivation and the maintenance of the transcriptionally active latent reservoir. PMID:27055281

  12. The HSV-1 Latency-Associated Transcript Functions to Repress Latent Phase Lytic Gene Expression and Suppress Virus Reactivation from Latently Infected Neurons

    PubMed Central

    Nicoll, Michael P.; Hann, William; Shivkumar, Maitreyi; Harman, Laura E. R.; Connor, Viv; Coleman, Heather M.; Proença, João T.; Efstathiou, Stacey

    2016-01-01

    Herpes simplex virus 1 (HSV-1) establishes life-long latent infection within sensory neurons, during which viral lytic gene expression is silenced. The only highly expressed viral gene product during latent infection is the latency-associated transcript (LAT), a non-protein coding RNA that has been strongly implicated in the epigenetic regulation of HSV-1 gene expression. We have investigated LAT-mediated control of latent gene expression using chromatin immunoprecipitation analyses and LAT-negative viruses engineered to express firefly luciferase or β-galactosidase from a heterologous lytic promoter. Whilst we were unable to determine a significant effect of LAT expression upon heterochromatin enrichment on latent HSV-1 genomes, we show that reporter gene expression from latent HSV-1 genomes occurs at a greater frequency in the absence of LAT. Furthermore, using luciferase reporter viruses we have observed that HSV-1 gene expression decreases during long-term latent infection, with a most marked effect during LAT-negative virus infection. Finally, using a fluorescent mouse model of infection to isolate and culture single latently infected neurons, we also show that reactivation occurs at a greater frequency from cultures harbouring LAT-negative HSV-1. Together, our data suggest that the HSV-1 LAT RNA represses HSV-1 gene expression in small populations of neurons within the mouse TG, a phenomenon that directly impacts upon the frequency of reactivation and the maintenance of the transcriptionally active latent reservoir. PMID:27055281

  13. Treatment: Latent TB Infection (LTBI) and TB Disease

    MedlinePlus

    ... Search The CDC Cancel Submit Search The CDC Tuberculosis (TB) Note: Javascript is disabled or is not ... message, please visit this page: About CDC.gov . Tuberculosis Basic TB Facts How TB Spreads Latent TB ...

  14. T-cell reprogramming through targeted CD4-coreceptor and T-cell receptor expression on maturing thymocytes by latent Circoviridae family member porcine circovirus type 2 cell infections in the thymus

    PubMed Central

    Klausmann, Stefanie; Sydler, Titus; Summerfield, Artur; Lewis, Fraser I; Weilenmann, Roseline; Sidler, Xaver; Brugnera, Enrico

    2015-01-01

    Although porcine circovirus type 2 (PCV2)-associated diseases have been evaluated for known immune evasion strategies, the pathogenicity of these viruses remained concealed for decades. Surprisingly, the same viruses that cause panzootics in livestock are widespread in young, unaffected animals. Recently, evidence has emerged that circovirus-like viruses are also linked to complex diseases in humans, including children. We detected PCV2 genome-carrying cells in fetal pig thymi. To elucidate virus pathogenicity, we developed a new pig infection model by in vivo transfection of recombinant PCV2 and the immunosuppressant cofactor cyclosporine A. Using flow cytometry, immunofluorescence and fluorescence in situ hybridization, we found evidence that PCV2 dictates positive and negative selection of maturing T cells in the thymus. We show for the first time that PCV2-infected cells reside at the corticomedullary junction of the thymus. In diseased animals, we found polyclonal deletion of single positive cells (SPs) that may result from a loss of major histocompatibility complex class-II expression at the corticomedullary junction. The percentage of PCV2 antigen-presenting cells correlated with the degree of viremia and, in turn, the severity of the defect in thymocyte maturation. Moreover, the reversed T-cell receptor/CD4-coreceptor expression dichotomy on thymocytes at the CD4+CD8interm and CD4SP cell stage is viremia-dependent, resulting in a specific hypo-responsiveness of T-helper cells. We compare our results with the only other better-studied member of Circoviridae, chicken anemia virus. Our data show that PCV2 infection leads to thymocyte selection dysregulation, adding a valuable dimension to our understanding of virus pathogenicity. PMID:26038767

  15. Vascular dysfunction in young, mid-aged and aged mice with latent cytomegalovirus infections

    PubMed Central

    Gombos, R. B.; Brown, J. C.; Teefy, J.; Gibeault, R. L.; Conn, K. L.; Schang, L. M.

    2013-01-01

    Human cytomegalovirus (HCMV) is associated with vascular diseases in both immunosuppressed and immunocompetent individuals. CMV infections cycle between active and latent phases throughout life. We and others have shown vascular dysfunction during active mouse CMV (mCMV) infections. Few studies have examined changes in physiology during latent CMV infections, particularly vascular responses or whether the negative effects of aging on vascular function and fertility will be exacerbated under these conditions. We measured vascular responses in intact mesenteric and uterine arteries dissected from young, mid-aged, and aged latently mCMV-infected (mCMV genomes are present but infectious virus is undetectable) and age-matched uninfected mice using a pressure myograph. We tested responses to the α1-adrenergic agonist phenylephrine, the nitric oxide donor sodium nitroprusside, and the endothelium-dependent vasodilator methacholine. In young latently mCMV-infected mice, vasoconstriction was increased and vasodilation was decreased in mesenteric arteries, whereas both vasoconstriction and vasodilation were increased in uterine arteries compared with those in age-matched uninfected mice. In reproductively active mid-aged latently infected mice, mesenteric arteries showed little change, whereas uterine arteries showed greatly increased vasoconstriction. These vascular effects may have contributed to the decreased reproductive success observed in mid-aged latently mCMV-infected compared with age-matched uninfected mice (16.7 vs. 46.7%, respectively). In aged latently infected mice, vasodilation is increased in mesenteric and uterine arteries likely to compensate for increased vasoconstriction to mediators other than phenylephrine. The novel results of this study show that even when active mCMV infections become undetectable, vascular dysfunction continues and differs with age and artery origin. PMID:23125213

  16. Immune Protection against Virus Challenge in Aging Mice Is Not Affected by Latent Herpesviral Infections

    PubMed Central

    Marandu, Thomas F.; Oduro, Jennifer D.; Borkner, Lisa; Dekhtiarenko, Iryna; Uhrlaub, Jennifer L.; Drabig, Anja; Kröger, Andrea; Nikolich-Zugich, Janko

    2015-01-01

    Latent herpesvirus infections alter immune homeostasis. To understand if this results in aging-related loss of immune protection against emerging infections, we challenged old mice carrying latent mouse cytomegalovirus (CMV), herpes simplex virus 1 (HSV-1), and/or murine gammaherpesvirus 68 (MHV-68) with influenza virus, West Nile virus (WNV), or vesicular stomatitis virus (VSV). We observed no increase in mortality or weight loss compared to results seen with herpesvirus-negative counterparts and a relative but not absolute reduction in CD8 responses to acute infections. Therefore, the presence of herpesviruses does not appear to increase susceptibility to emerging infections in aging patients. PMID:26339051

  17. Therapeutic Immunization with a Mixture of Herpes Simplex Virus 1 Glycoprotein D-Derived “Asymptomatic” Human CD8+ T-Cell Epitopes Decreases Spontaneous Ocular Shedding in Latently Infected HLA Transgenic Rabbits: Association with Low Frequency of Local PD-1+ TIM-3+ CD8+ Exhausted T Cells

    PubMed Central

    Khan, Arif A.; Srivastava, Ruchi; Chentoufi, Aziz A.; Geertsema, Roger; Thai, Nhi Thi Uyen; Dasgupta, Gargi; Osorio, Nelson; Kalantari, Mina; Nesburn, Anthony B.; Wechsler, Steven L.

    2015-01-01

    ABSTRACT Most blinding ocular herpetic disease is due to reactivation of herpes simplex virus 1 (HSV-1) from latency rather than to primary acute infection. No herpes simplex vaccine is currently available for use in humans. In this study, we used the HLA-A*02:01 transgenic (HLA Tg) rabbit model of ocular herpes to assess the efficacy of a therapeutic vaccine based on HSV-1 gD epitopes that are recognized mainly by CD8+ T cells from “naturally” protected HLA-A*02:01-positive, HSV-1-seropositive healthy asymptomatic (ASYMP) individuals (who have never had clinical herpes disease). Three ASYMP CD8+ T-cell epitopes (gD53–61, gD70–78, and gD278–286) were linked with a promiscuous CD4+ T-cell epitope (gD287–317) to create 3 separate pairs of CD4-CD8 peptides, which were then each covalently coupled to an Nε-palmitoyl-lysine moiety, a Toll-like receptor 2 (TLR-2) ligand. This resulted in the construction of 3 CD4-CD8 lipopeptide vaccines. Latently infected HLA Tg rabbits were immunized with a mixture of these 3 ASYMP lipopeptide vaccines, delivered as eye drops in sterile phosphate-buffered saline (PBS). The ASYMP therapeutic vaccination (i) induced HSV-specific CD8+ T cells that prevent HSV-1 reactivation ex vivo from latently infected explanted trigeminal ganglia (TG), (ii) significantly reduced HSV-1 shedding detected in tears, (iii) boosted the number and function of HSV-1 gD epitope-specific CD8+ T cells in draining lymph nodes (DLN), conjunctiva, and TG, and (iv) was associated with fewer exhausted HSV-1 gD-specific PD-1+ TIM-3+ CD8+ T cells. The results underscore the potential of an ASYMP CD8+ T-cell epitope-based therapeutic vaccine strategy against recurrent ocular herpes. IMPORTANCE Seventy percent to 90% of adults harbor herpes simplex virus 1 (HSV-1), which establishes lifelong latency in sensory neurons of the trigeminal ganglia. This latent state sporadically switches to spontaneous reactivation, resulting in viral shedding in tears. Most

  18. CCL2/MCP-I Genotype-Phenotype Relationship in Latent Tuberculosis Infection

    PubMed Central

    Hussain, Rabia; Ansari, Ambreen; Talat, Najeeha; Hasan, Zahra; Dawood, Ghaffar

    2011-01-01

    Among the known biomarkers, chemokines, secreted by activated macrophages and T cells, attract groups of immune cells to the site of infection and may determine the clinical outcome. Association studies of CCL-2/MCP-1 -2518 A/G functional SNP linked to high and low phenotypes with tuberculosis disease susceptibility have shown conflicting results in tuberculosis. Some of these differences could be due the variability of latent infection and recent exposure in the control groups. We have therefore carried out a detailed analysis of CCL-2 genotype SNP -2518 (A/G transition) with plasma CCL-2 levels and related these levels to tuberculin skin test positivity in asymptomatic community controls with no known exposure to tuberculosis and in recently exposed household contacts of pulmonary tuberculosis patients. TST positivity was linked to higher concentrations of plasma CCL2 (Mann Whitney U test; p = 0.004) and was more marked when the G allele was present in TST+ asymptomatic controls (A/G; p = 0.01). Recent exposure also had a significant effect on CCL-2 levels and was linked to the G allele (p = 0.007). Therefore association studies for susceptibility or protection from disease should take into consideration the PPD status as well as recent exposure of the controls group used for comparison. Our results also suggest a role for CCL-2 in maintaining the integrity of granuloma in asymptomatic individuals with latent infection in high TB burden settings. Therefore additional studies into the role of CCL-2 in disease reactivation and progression are warranted. PMID:21991356

  19. CCL2/MCP-I genotype-phenotype relationship in latent tuberculosis infection.

    PubMed

    Hussain, Rabia; Ansari, Ambreen; Talat, Najeeha; Hasan, Zahra; Dawood, Ghaffar

    2011-01-01

    Among the known biomarkers, chemokines, secreted by activated macrophages and T cells, attract groups of immune cells to the site of infection and may determine the clinical outcome. Association studies of CCL-2/MCP-1 -2518 A/G functional SNP linked to high and low phenotypes with tuberculosis disease susceptibility have shown conflicting results in tuberculosis. Some of these differences could be due the variability of latent infection and recent exposure in the control groups. We have therefore carried out a detailed analysis of CCL-2 genotype SNP -2518 (A/G transition) with plasma CCL-2 levels and related these levels to tuberculin skin test positivity in asymptomatic community controls with no known exposure to tuberculosis and in recently exposed household contacts of pulmonary tuberculosis patients. TST positivity was linked to higher concentrations of plasma CCL2 (Mann Whitney U test; p = 0.004) and was more marked when the G allele was present in TST+ asymptomatic controls (A/G; p = 0.01). Recent exposure also had a significant effect on CCL-2 levels and was linked to the G allele (p = 0.007). Therefore association studies for susceptibility or protection from disease should take into consideration the PPD status as well as recent exposure of the controls group used for comparison. Our results also suggest a role for CCL-2 in maintaining the integrity of granuloma in asymptomatic individuals with latent infection in high TB burden settings. Therefore additional studies into the role of CCL-2 in disease reactivation and progression are warranted. PMID:21991356

  20. A novel method for selecting antagonists against postharvest fruit decays originating from latent infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological control of fruit decays originating from wound infections after harvest has made great progress during the past two decades and several products are commercially available. However, this is not the case for postharvest decays originating from latent infections which occur in the orchard....

  1. Selecting antagonists for control of postharvest brown rot of stone fruits originating from latent infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In contrast to biological control of postharvest decays (BCPD) of fruits originating from wound infections after harvest, BCPD originating from latent infections occurring in the orchard has not been developed. This is largely due to the lack of methodology to screen and evaluate microbes for bioco...

  2. RNA from an immediate early region of the type 1 herpes simplex virus genome is present in the trigeminal ganglia of latently infected mice

    SciTech Connect

    Deatly, A.M.; Spivack, J.G.; Lavi, E.; Fraser, N.W.

    1987-05-01

    Transcription of the type 1 herpes simplex virus (HSV-1) genome in trigeminal ganglia of latently infected mice was studied using in situ hybridization. Probes representative of each temporal gene class were used to determine the regions of the genome that encode the transcripts present in latently infected cells. Probes encoding HSV-1 sequences of the five immediate early genes and representative early (thymidine kinase), early-late (major capsid protein), and late (glycoprotein C) genes were used in these experiments. Of the probes tested, only those encoding the immediate early gene product infected-cell polypeptide (ICP) 0 hybridized to RNA in latently infected tissues. Probes containing the other immediate early genes (ICP4, ICP22, ICP27, and ICP47) and the representative early, early-late, and late genes did not hybridize. Two probes covering approx. = 30% of the HSV-1 genome and encoding over 20 early and late transcripts also did not hybridize to RNA in latently infected tissues. These results, with probes spanning > 60% of the HSV-1 genome, suggest that transcription of the HSV-1 genome is restricted to one region in latently infected mouse trigeminal ganglia.

  3. Latent Toxoplasma gondii infection leads to deficits in goal-directed behavior in healthy elderly.

    PubMed

    Beste, Christian; Getzmann, Stephan; Gajewski, Patrick D; Golka, Klaus; Falkenstein, Michael

    2014-05-01

    Goal-directed behavior is well-known to show declines in elderly individuals, possibly because of alterations in dopaminergic neural transmission. The dopaminergic system is modulated by a number of other different factors. One of these factors, which has attracted a considerable amount of interest in neurobiology, but has only rarely been examined with respect to its possible modulatory role for cognitive functions in elderly individuals, is latent Toxoplasma gondii (T. gondii) infection. Latent T. gondii infection may be of relevance to goal-directed behavior as it alters dopaminergic neural transmission. We examine goal-directed behavior in T. gondii IgG positive and negative elderly subjects in auditory distraction paradigm. We apply event-related potentials to examine which cognitive subprocesses are affected by latent T. gondii infection on a neurophysiological level. We show that latent T. gondii infection compromises the management of auditory distraction in elderly by specifically delaying processes of attentional allocation and disengagement. The results show that latent T. gondii infection is neglected but an important neurobiological modulator of cognitive functions in elderly individuals. PMID:24315729

  4. Latent progenitor cells as potential regulators for tympanic membrane regeneration

    NASA Astrophysics Data System (ADS)

    Kim, Seung Won; Kim, Jangho; Seonwoo, Hoon; Jang, Kyung-Jin; Kim, Yeon Ju; Lim, Hye Jin; Lim, Ki-Taek; Tian, Chunjie; Chung, Jong Hoon; Choung, Yun-Hoon

    2015-06-01

    Tympanic membrane (TM) perforation, in particular chronic otitis media, is one of the most common clinical problems in the world and can present with sensorineural healing loss. Here, we explored an approach for TM regeneration where the latent progenitor or stem cells within TM epithelial layers may play an important regulatory role. We showed that potential TM stem cells present highly positive staining for epithelial stem cell markers in all areas of normal TM tissue. Additionally, they are present at high levels in perforated TMs, especially in proximity to the holes, regardless of acute or chronic status, suggesting that TM stem cells may be a potential factor for TM regeneration. Our study suggests that latent TM stem cells could be potential regulators of regeneration, which provides a new insight into this clinically important process and a potential target for new therapies for chronic otitis media and other eardrum injuries.

  5. Latent tuberculosis infection: screening and treatment in an urban setting.

    PubMed

    Morano, Jamie P; Walton, Mary R; Zelenev, Alexei; Bruce, R Douglas; Altice, Frederick L

    2013-10-01

    Despite its benefit for treating active tuberculosis, directly observed therapy (DOT) for latent tuberculosis infection (LTBI) has been largely understudied among challenging inner city populations. Utilizing questionnaire data from a comprehensive mobile healthcare clinic in New Haven, CT from 2003 to July 2011, a total of 2,523 completed tuberculin skin tests (TSTs) resulted in 356 new LTBIs. Multivariate logistic regression correlated covariates of the two outcomes (a) initiation of isoniazid preventative therapy (IPT) and (b) completion of 9 months of IPT. Of the 357 newly positive TSTs, 86.3 % (n = 308) completed screening chest radiographs (CXRs): 90.3 % (n = 278) were normal, and 0.3 % (n = 1) had active tuberculosis. Of those completing CXR screening, 44.0 % (n = 135) agreed to IPT: 69.6 % (n = 94) selected DOT, and 30.4 % (n = 41) selected self-administered therapy (SAT). Initiating IPT was correlated with undocumented status (AOR = 3.43; p < 0.001) and being born in a country of highest and third highest tuberculosis prevalence (AOR = 14.09; p = 0.017 and AOR = 2.25; p = 0.005, respectively). Those selecting DOT were more likely to be Hispanic (83.0 vs 53.7 %; p < 0.0001), undocumented (57.4 vs 41.5 %; p = 0.012), employed (p < 0.0001), uninsured (p = 0.014), and have stable housing (p = 0.002), no prior cocaine or crack use (p = 0.013) and no recent incarceration (p = 0.001). Completing 9 months of IPT was correlated with no recent incarceration (AOR 5.95; p = 0.036) and younger age (AOR 1.03; p = 0.031). SAT and DOT participants did not significantly differ for IPT duration (6.54 vs 5.68 months; p = 0.216) nor 9-month completion (59.8 vs 46.3 %; p = 0.155). In an urban mobile healthcare sample, screening completion for LTBI was high with nearly half initiating IPT. Undocumented, Hispanic immigrants from high prevalence tuberculosis countries were more likely to self-select DOT at the mobile

  6. Determination of Urinary Neopterin/Creatinine Ratio to Distinguish Active Tuberculosis from Latent Mycobacterium tuberculosis Infection

    PubMed Central

    Eisenhut, Michael; Hargreaves, Dougal S.; Scott, Anne; Housley, David; Walters, Andrew; Mulla, Rohinton

    2016-01-01

    Background. Biomarkers to distinguish latent from active Mycobacterium (M.) tuberculosis infection in clinical practice are lacking. The urinary neopterin/creatinine ratio can quantify the systemic interferon-gamma effect in patients with M. tuberculosis infection. Methods. In a prospective observational study, urinary neopterin levels were measured by enzyme linked immunosorbent assay in patients with active tuberculosis, in people with latent M. tuberculosis infection, and in healthy controls and the urinary neopterin/creatinine ratio was calculated. Results. We included a total of 44 patients with M. tuberculosis infection and nine controls. 12 patients had active tuberculosis (8 of them culture-confirmed). The median age was 15 years (range 4.5 to 49). Median urinary neopterin/creatinine ratio in patients with active tuberculosis was 374.1 micromol/mol (129.0 to 1072.3), in patients with latent M. tuberculosis infection it was 142.1 (28.0 to 384.1), and in controls it was 146.0 (40.3 to 200.0), with significantly higher levels in patients with active tuberculosis (p < 0.01). The receiver operating characteristics curve had an area under the curve of 0.84 (95% CI 0.70 to 0.97) (p < 0.01). Conclusions. Urinary neopterin/creatinine ratios are significantly higher in patients with active tuberculosis compared to patients with latent infection and may be a significant predictor of active tuberculosis in patients with M. tuberculosis infection. PMID:27433370

  7. Immunization against Genital Herpes with a Vaccine Virus That has Defects in Productive and Latent Infection

    NASA Astrophysics Data System (ADS)

    da Costa, Xavier J.; Jones, Cheryl A.; Knipe, David M.

    1999-06-01

    An effective vaccine for genital herpes has been difficult to achieve because of the limited efficacy of subunit vaccines and the safety concerns about live viruses. As an alternative approach, mutant herpes simplex virus strains that are replication-defective can induce protective immunity. To increase the level of safety and to prove that replication was not needed for immunization, we constructed a mutant herpes simplex virus 2 strain containing two deletion mutations, each of which eliminated viral replication. The double-mutant virus induces protective immunity that can reduce acute viral shedding and latent infection in a mouse genital model, but importantly, the double-mutant virus shows a phenotypic defect in latent infection. This herpes vaccine strain, which is immunogenic but has defects in both productive and latent infection, provides a paradigm for the design of vaccines and vaccine vectors for other sexually transmitted diseases, such as AIDS.

  8. Protection against Recurrent Ocular Herpes Simplex Virus Type 1 Disease after Therapeutic Vaccination of Latently Infected Mice

    PubMed Central

    Richards, C. M.; Case, R.; Hirst, T. R.; Hill, T. J.; Williams, N. A.

    2003-01-01

    The potential of therapeutic vaccination of animals latently infected with herpes simplex virus type 1 (HSV-1) to enhance protective immunity to the virus and thereby reduce the incidence and severity of recurrent ocular disease was assessed in a mouse model. Mice latently infected with HSV-1 were vaccinated intranasally with a mixture of HSV-1 glycoproteins and recombinant Escherichia coli heat-labile enterotoxin B subunit (rEtxB) as an adjuvant. The systemic immune response induced was characterized by high levels of virus-specific immunoglobulin G1 (IgG1) in serum and very low levels of IgG2a. Mucosal immunity was demonstrated by high levels of IgA in eye and vaginal secretions. Proliferating T cells from lymph nodes of vaccinated animals produced higher levels of interleukin-10 (IL-10) than were produced by such cells from mock-vaccinated animals. This profile suggests that vaccination of latently infected mice modulates the Th1-dominated proinflammatory response usually induced upon infection. After reactivation of latent virus by UV irradiation, vaccinated mice showed reduced viral shedding in tears as well as a reduction in the incidence of recurrent herpetic corneal epithelial disease and stromal disease compared with mock-vaccinated mice. Moreover, vaccinated mice developing recurrent ocular disease showed less severe signs and a quicker recovery rate. Spread of virus to other areas close to the eye, such as the eyelid, was also significantly reduced. Encephalitis occurred in a small percentage (11%) of mock-vaccinated mice, but vaccinated animals were completely protected from such disease. The possible immune mechanisms involved in protection against recurrent ocular herpetic disease in therapeutically vaccinated animals are discussed. PMID:12767989

  9. Single-Cell Cytokine Gene Expression in Peripheral Blood Cells Correlates with Latent Tuberculosis Status

    PubMed Central

    Lakehal, Karim; Davidow, Amy L.; Pine, Richard; Tyagi, Sanjay; Bushkin, Yuri; Lardizabal, Alfred; Gennaro, Maria Laura

    2015-01-01

    RNA flow cytometry (FISH-Flow) achieves high-throughput measurement of single-cell gene expression by combining in-situ nucleic acid hybridization with flow cytometry. We tested whether antigen-specific T-cell responses detected by FISH-Flow correlated with latent tuberculosis infection (LTBI), a condition affecting one-third of the world population. Peripheral-blood mononuclear cells from donors, identified as positive or negative for LTBI by current medical practice, were stimulated ex vivo with mycobacterial antigen. IFNG and IL2 mRNA production was assayed by FISH-Flow. Concurrently, immunophenotypes of the cytokine mRNA-positive cells were characterized by conventional, antibody-based staining of cell-surface markers. An association was found between donor LTBI status and antigen-specific induction of IFNG and IL2 transcripts. Induction of these cytokine genes, which was detected by FISH-Flow in a quarter the time required to see release of the corresponding proteins by ELISA, occurred primarily in activated CD4+ T cells via T-cell receptor engagement. Moreover, NK cells contributed to IFNG gene induction. These results show that antigen-driven induction of T-cell cytokine mRNA is a measurable single-cell parameter of the host responses associated with latent tuberculosis. FISH-Flow read-outs contribute a multi-scale dimension to the immunophenotyping afforded by antibody-based flow cytometry. Multi-scale, single-cell analyses may satisfy the need to determine disease stage and therapy response for tuberculosis and other infectious pathologies. PMID:26658491

  10. Vitamin D3 inhibits TNFα-induced latent HIV reactivation in J-LAT cells.

    PubMed

    Nunnari, G; Fagone, P; Lazzara, F; Longo, A; Cambria, D; Di Stefano, G; Palumbo, M; Malaguarnera, L; Di Rosa, Michelino

    2016-07-01

    1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) is known to suppress NF-kB activity by interfering with its pathways. The aim of this study was to investigate the ability of 1,25(OH)2D3 in reducing the reactivation of the HIV virus J-LAT cells, an established model of latently infected cells, which were treated with TNFalpha (100 ng/ml) for 2 h with or without 24 h 1,25(OH)2D3 (100 nM) pretreatment. Reactivation of HIV RNA in J-LAT was evaluated in terms of green fluorescent protein (GFP) expression. The same experimental setting was repeated on T cells from HIV-infected patients. Treatment with TNFalpha was associated with a 16 % increase in GFP+ cells and a five-fold increase in unspliced HIV RNA expression (p < 0.04). Pretreatment of J-LAT cells with 1,25(OH)2D3 for 24 h followed by TNFalpha (100 ng/ml) for 2 h reduced the percentage of GFP+ cells by 8 %; moreover, a 2.4-fold decrease in unspliced HIV RNA expression was observed (p < 0.002). In T cells from patients, treatment with TNFalpha significantly increased unspliced HIV RNA expression (sixfold increase, p < 0.02), whereas prestimulation with 1,25(OH)2D3 reduced its expression (2.5-fold decrease, p < 0.02) compared to controls.1,25(OH)2D3 is able to reduce the ability of TNFalpha to upregulate the transcription of HIV RNA from latently infected cells. These data provide further understanding of the pathogenic mechanisms regulating viral reactivation from latent reservoirs, along with new insight in viral internalization. PMID:27295094

  11. Prevention of Tumor Formation by Latent Gammaherpesvirus Infection

    PubMed Central

    Raffegerst, S.; Steer, B.; Hohloch, M.; Adler, H.

    2015-01-01

    Recent reports suggested that chronic herpesvirus infection, as a constituent of the so-called virome, may not only exert harmful effects but may also be beneficial to the host, for example mediating increased resistance to secondary infections or to tumors. To further challenge this concept, specifically regarding increased resistance to tumors, we infected chimeric HLA-DR4-H2-E (DR4) mice, a mouse strain which spontaneously develops hematological tumors, with the rodent herpesvirus murine gammaherpesvirus 68 (MHV-68). Using this model, we observed that infection with wildtype MHV-68 completely prevented tumor formation. This happened, however, at the cost of hyposplenism. In contrast to wildtype infection, infection with a latency-deficient mutant of MHV-68 neither prevented tumor formation nor induced hyposplenism. The underlying mechanisms are not known but might be related to an infection-mediated priming of the immune response, resulting in the suppression of a tumor promoting endogenous retrovirus. Thus, under certain circumstances, chronic herpesvirus infection may prevent the development of tumors. PMID:26714031

  12. Isoniazid Completion Rates for Latent Tuberculosis Infection among College Students Managed by a Community Pharmacist

    ERIC Educational Resources Information Center

    Hess, Karl; Goad, Jeffery; Wu, Joanne; Johnson, Kathleen

    2009-01-01

    Objective: The authors' objective was to document 9-month and previously recommended 6-month treatment completion rates for latent tuberculosis infection (LTBI) in a pharmacist-managed LTBI clinic in a community pharmacy on a college campus, and to describe patient characteristics. Participants: Participants were university students diagnosed with…

  13. Latent Gammaherpesvirus 68 Infection Induces Distinct Transcriptional Changes in Different Organs

    PubMed Central

    Canny, Susan P.; Goel, Gautam; Reese, Tiffany A.; Zhang, Xin; Xavier, Ramnik

    2014-01-01

    Previous studies identified a role for latent herpesvirus infection in cross-protection against infection and exacerbation of chronic inflammatory diseases. Here, we identified more than 500 genes differentially expressed in spleens, livers, or brains of mice latently infected with gammaherpesvirus 68 and found that distinct sets of genes linked to different pathways were altered in the spleen compared to those in the liver. Several of the most differentially expressed latency-specific genes (e.g., the gamma interferon [IFN-γ], Cxcl9, and Ccl5 genes) are associated with known latency-specific phenotypes. Chronic herpesvirus infection, therefore, significantly alters the transcriptional status of host organs. We speculate that such changes may influence host physiology, the status of the immune system, and disease susceptibility. PMID:24155394

  14. Anatomical Response and Infection of Soybean during Latent and Pathogenic Infection by Type A and B of Phialophora gregata

    PubMed Central

    Impullitti, Ann E.; Malvick, Dean K.

    2014-01-01

    Growth and anatomical responses of plants during latent and pathogenic infection by fungal pathogens are not well understood. The interactions between soybean (Glycine max) and two types of the pathogen Phialophora gregata were investigated to determine how plants respond during latent and pathogenic infection. Stems of soybean cultivars with different or no genes for resistance to infection by P. gregata were inoculated with wildtype or GFP and RFP-labeled strains of types A or B of P. gregata. Plants were sectioned during latent and pathogenic infection, examined with transmitted light or fluorescent microscopy, and quantitative differences in vessels and qualitative differences in infection were assessed using captured images. During latent infection, the number of vessels was similar in resistant and susceptible plants infected with type A or B compared to the control, and fungal infection was rarely observed in vessels. During pathogenic infection, the resistant cultivars had 20 to 25% more vessels than the uninfected plants, and fungal hyphae were readily observed in the vessels. Furthermore, during the pathogenic phase in a resistant cultivar, P.gregata type A-GFP was limited to outside of the primary xylem, while P.gregata type B-RFP was observed in the primary xylem. The opposite occurred with the susceptible cultivar, where PgA-GFP was observed in the primary xylem and PgB-RFP was limited to the interfascicular region. In summary, soybean cultivars with resistance to BSR produced more vessels and can restrict or exclude P. gregata from the vascular system compared to susceptible cultivars. Structural resistance mechanisms potentially compensate for loss of vessel function and disrupted water movement. PMID:24879418

  15. Protection from genital herpes disease, seroconversion and latent infection in a non-lethal murine genital infection model by immunization with an HSV-2 replication-defective mutant virus.

    PubMed

    Diaz, Fernando M; Knipe, David M

    2016-01-15

    Viral vaccines have traditionally protected against disease, but for viruses that establish latent infection, it is desirable for the vaccine to reduce infection to reduce latent infection and reactivation. While seroconversion has been used in clinical trials of herpes simplex virus (HSV) vaccines to measure protection from infection, this has not been modeled in animal infection systems. To measure the ability of a genital herpes vaccine candidate to protect against various aspects of infection, we established a non-lethal murine model of genital HSV-2 infection, an ELISA assay to measure antibodies specific for infected cell protein 8 (ICP8), and a very sensitive qPCR assay. Using these assays, we observed that immunization with HSV-2 dl5-29 virus reduced disease, viral shedding, seroconversion, and latent infection by the HSV-2 challenge virus. Therefore, it may be feasible to obtain protection against genital disease, seroconversion and latent infection by immunization, even if sterilizing immunity is not achieved. PMID:26609935

  16. IFN-γ release assays in the diagnosis of latent tuberculosis infection among immunocompromised adults.

    PubMed

    Redelman-Sidi, Gil; Sepkowitz, Kent A

    2013-08-15

    Immunocompromised persons with latent tuberculosis infection (LTBI) are at increased risk for tuberculosis reactivation compared with the general population. The tuberculin skin test, the traditional assay for diagnosing LTBI, has reduced accuracy in immunocompromised patients. IFN-γ release assays (IGRAs) are in vitro blood tests that measure T-cell release of IFN-γ after stimulation with antigens unique to Mycobacterium tuberculosis. Here we review the data for the use of QuantiFERON-TB Gold In-Tube and T-SPOT.TB, the two currently available IGRAs, in immunocompromised adults, including persons infected with HIV, patients with immune-mediated inflammatory disorders, candidates for treatment with tumor necrosis factor-α inhibitors, patients receiving hemodialysis, solid-organ transplant recipients, and patients with cancer. On the basis of the available data, IGRAs have advantages over the tuberculin skin test in specific patient populations and in certain situations. Further studies are needed to more accurately define the usefulness of IGRAs in immunocompromised patients. PMID:23262514

  17. Detection of the latency-associated transcript in neuronal cultures during the latent infection with herpes simplex virus type 1.

    PubMed

    Doerig, C; Pizer, L I; Wilcox, C L

    1991-07-01

    The transcriptional studies reported in this paper indicate that the latency-associated transcript (LAT) is present in neuronal cultures during the latent infection with herpes simplex virus type 1 (HSV-1). During the latent infection glycoprotein D (gD) mRNA, a mRNA characteristic of the productive infection, is not detected. However, following reactivation by nerve growth factor (NGF) deprivation, gD mRNA is detected in the neuronal cultures. Thus, the restricted viral gene expression in the in vitro neuronal model indicates that the latent infection in culture is analogous to that observed in vivo. PMID:1647075

  18. Stimulating the RIG-I pathway to kill cells in the latent HIV reservoir following viral reactivation

    PubMed Central

    Li, Peilin; Kaiser, Philipp; Lampiris, Harry W.; Kim, Peggy; Yukl, Steven A.; Havlir, Diane V.; Greene, Warner C.; Wong, Joseph K.

    2016-01-01

    The persistence of latent HIV proviruses in long-lived CD4+ T cells despite antiretroviral therapy (ART)1–3 is a major obstacle to viral eradication4–6. Because current candidate latency-reversing agents (LRAs) induce HIV transcription but fail to clear these cellular reservoirs,7–8 new approaches for killing these reactivated latent HIV reservoir cells are urgently needed. HIV latency depends upon transcriptional quiescence of the integrated provirus and circumvention of immune defense mechanisms4–6,9. These defenses include cell-intrinsic innate responses that use pattern-recognition receptors (PRR) to detect viral pathogens and subsequently induce apoptosis of the infected cell10. Retinoic acid-inducible gene I (RIG-I) forms one class of pattern-recognition receptors that mediates apoptosis and elimination of infected cells after recognition of viral RNA11–14. Here we show that acitretin, an FDA-approved retinoic-acid derivative, enhances RIG-I signaling ex vivo, increases HIV transcription, and induces preferential apoptosis of HIV-infected cells. These effects are abrogated by RIG-I knockdown. Acitretin also decreases proviral DNA levels in CD4+ T cells from HIV-infected subjects on suppressive ART, an effect amplified by combination with suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor. Pharmacologic enhancement of an innate cellular defense network could provide a means to eliminate reactivated cells in the latent HIV reservoir. PMID:27294875

  19. Recognition of Stage-Specific Mycobacterial Antigens Differentiates between Acute and Latent Infections with Mycobacterium tuberculosis

    PubMed Central

    Demissie, Abebech; Leyten, Eliane M. S.; Abebe, Markos; Wassie, Liya; Aseffa, Abraham; Abate, Getahun; Fletcher, Helen; Owiafe, Patrick; Hill, Philip C.; Brookes, Roger; Rook, Graham; Zumla, Alimuddin; Arend, Sandra M.; Klein, Michel; Ottenhoff, Tom H. M.; Andersen, Peter; Doherty, T. Mark

    2006-01-01

    Mycobacterium tuberculosis is estimated to infect 80 to 100 million people annually, the majority of whom do not develop clinical tuberculosis (TB) but instead maintain the infection in a latent state. These individuals generally become positive in response to a tuberculin skin test and may develop clinical TB at a later date, particularly if their immune systems are compromised. Latently infected individuals are interesting for two reasons. First, they are an important reservoir of M. tuberculosis, which needs to be considered for TB control. Second, if detected prior to recrudescence of the disease, they represent a human population that is making a protective immune response to M. tuberculosis, which is very important for defining correlates of protective immunity. In this study, we show that while responsiveness to early secretory antigenic target 6 is a good marker for M. tuberculosis infection, a strong response to the 16-kDa Rv2031c antigen (HspX or α-crystallin) is largely restricted to latently infected individuals, offering the possibility of differential immunodiagnosis of, or therapeutic vaccination against, TB. PMID:16467323

  20. Localization of latency-associated transcripts in the uterovaginal plexus of herpes simplex virus type 1 and 2 latently infected mice.

    PubMed

    Podlech, J; Hengerer, F; Fleck, M; Kunkel, J; Falke, D

    1997-05-01

    The vagina and medulla of the adrenal gland of mice vaginally infected with herpes simplex virus (HSV) types 1 and 2 were examined in the latent stage of infection (5 to 51 weeks post-infection). RNA in situ hybridization with HSV-1 and -2 latency-associated transcript (LAT) RNA probes resulted in positively stained neuronal cell nuclei in the uterovaginal plexus, but not in the medulla of the adrenal gland. These organs were chosen because HSV antigens can be detected not only in the vaginal epithelium, but also in neurons of the uterovaginal plexus and in the medulla of the adrenal gland at the acute stage of genital infection. To our knowledge, this is the first report describing LATs in neurons of the uterovaginal plexus in the genital tract of latently HSV-infected mice. PMID:9152429

  1. Transcription of genes involved in sulfolipid and polyacyltrehalose biosynthesis of Mycobacterium tuberculosis in experimental latent tuberculosis infection.

    PubMed

    Rodríguez, Jimmy E; Ramírez, Ana S; Salas, Laura P; Helguera-Repetto, Cecilia; Gonzalez-y-Merchand, Jorge; Soto, Carlos Y; Hernández-Pando, Rogelio

    2013-01-01

    The Influence of trehalose-based glycolipids in the virulence of Mycobacterium tuberculosis (Mtb) is recognised; however, the actual role of these cell-wall glycolipids in latent infection is unknown. As an initial approach, we determined by two-dimensional thin-layer chromatography the sulfolipid (SL) and diacyltrehalose/polyacyltrehalose (DAT/PAT) profile of the cell wall of hypoxic Mtb. Then, qRT-PCR was extensively conducted to determine the transcription profile of genes involved in the biosynthesis of these glycolipids in non-replicating persistent 1 (NRP1) and anaerobiosis (NRP2) models of hypoxia (Wayne model), and murine models of chronic and progressive pulmonary tuberculosis. A diminished content of SL and increased amounts of glycolipids with chromatographic profile similar to DAT were detected in Mtb grown in the NRP2 stage. A striking decrease in the transcription of mmpL8 and mmpL10 transporter genes and increased transcription of the pks (polyketidesynthase) genes involved in SL and DAT biosynthesis were detected in both the NRP2 stage and the murine model of chronic infection. All genes were found to be up-regulated in the progressive disease. These results suggest that SL production is diminished during latent infection and the DAT/PAT precursors can be accumulated inside tubercle bacilli and are possibly used in reactivation processes. PMID:23472191

  2. Incidence of occupational latent tuberculosis infection in South African healthcare workers.

    PubMed

    Adams, Shahieda; Ehrlich, Rodney; Baatjies, Roslynn; van Zyl-Smit, Richard N; Said-Hartley, Qonita; Dawson, Rodney; Dheda, Keertan

    2015-05-01

    The test-specific incidence of latent tuberculosis infection (LTBI) in healthcare workers from sub-Saharan Africa is unknown. 505 healthcare workers from South Africa were screened at baseline, and after 12 months, with a questionnaire, the tuberculin skin test (TST), and two T-cell assays (T-SPOT.TB and QuantiFERON-TB Gold-In-Tube). Test-specific conversion rates were calculated. The prevalence of presumed LTBI at baseline was 84, 69 and 62% using the TST, QuantiFERON-TB Gold-In-Tube and T-SPOT.TB, respectively. The annual test-specific conversion rate, depending on the cut-off point used, was as follows: TST 38%; QuantiFERON-TB Gold-In-Tube 13-22%; and T-SPOT.TB 18-22%. Annual reversion rates were 4, 7 and 16%, respectively. The annual TST conversion rate was significantly higher than that derived from published local community-based data (IRR 3.53, 95% CI 1.81-6.88). Factors associated with conversion (any test) included healthcare sector of employment, counselling of tuberculosis patients, and a baseline positive TST (for T-SPOT.TB). The annual rate of tuberculosis infection in South African healthcare workers was very high, irrespective of the testing method used, and may be explained by occupational exposure, as the rate was considerably higher than non-healthcare workers from the same community. Collectively, these data support the need for implementation of tuberculosis-specific infection control measures in Africa. PMID:25700382

  3. De Novo Herpes Simplex Virus VP16 Expression Gates a Dynamic Programmatic Transition and Sets the Latent/Lytic Balance during Acute Infection in Trigeminal Ganglia.

    PubMed

    Sawtell, Nancy M; Thompson, Richard L

    2016-09-01

    The life long relationship between herpes simplex virus and its host hinges on the ability of the virus to aggressively replicate in epithelial cells at the site of infection and transport into the nervous system through axons innervating the infection site. Interaction between the virus and the sensory neuron represents a pivot point where largely unknown mechanisms lead to a latent or a lytic infection in the neuron. Regulation at this pivot point is critical for balancing two objectives, efficient widespread seeding of the nervous system and host survival. By combining genetic and in vivo in approaches, our studies reveal that the balance between latent and lytic programs is a process occurring early in the trigeminal ganglion. Unexpectedly, activation of the latent program precedes entry into the lytic program by 12 -14hrs. Importantly, at the individual neuronal level, the lytic program begins as a transition out of this acute stage latent program and this escape from the default latent program is regulated by de novo VP16 expression. Our findings support a model in which regulated de novo VP16 expression in the neuron mediates entry into the lytic cycle during the earliest stages of virus infection in vivo. These findings support the hypothesis that the loose association of VP16 with the viral tegument combined with sensory axon length and transport mechanisms serve to limit arrival of virion associated VP16 into neuronal nuclei favoring latency. Further, our findings point to specialized features of the VP16 promoter that control the de novo expression of VP16 in neurons and this regulation is a key component in setting the balance between lytic and latent infections in the nervous system. PMID:27607440

  4. Detection of herpes simplex virus-specific DNA sequences in latently infected mice and in humans.

    PubMed Central

    Efstathiou, S; Minson, A C; Field, H J; Anderson, J R; Wildy, P

    1986-01-01

    Herpes simplex virus-specific DNA sequences have been detected by Southern hybridization analysis in both central and peripheral nervous system tissues of latently infected mice. We have detected virus-specific sequences corresponding to the junction fragment but not the genomic termini, an observation first made by Rock and Fraser (Nature [London] 302:523-525, 1983). This "endless" herpes simplex virus DNA is both qualitatively and quantitatively stable in mouse neural tissue analyzed over a 4-month period. In addition, examination of DNA extracted from human trigeminal ganglia has shown herpes simplex virus DNA to be present in an "endless" form similar to that found in the mouse model system. Further restriction enzyme analysis of latently infected mouse brainstem and human trigeminal DNA has shown that this "endless" herpes simplex virus DNA is present in all four isomeric configurations. Images PMID:3003377

  5. Potential novel markers to discriminate between active and latent tuberculosis infection in Chinese individuals.

    PubMed

    Bai, Xue-juan; Liang, Yan; Yang, You-rong; Feng, Jin-dong; Luo, Zhan-peng; Zhang, Jun-Xian; Wu, Xue-qiong

    2016-02-01

    Latent tuberculosis infection (LTBI) constitutes the main reservoir for reactivation tuberculosis. The finding of potential biomarkers for differentiating between TB and LTBI is very necessary. In this study, the immunological characteristics and potential diagnostic utility of Rv2029c, Rv2628 and Rv1813c proteins were assessed. These three proteins stimulated PBMCs from ELISPOT-positive LTBI subjects produced higher levels of IFN-γ in comparison with TB patients and ELISPOT-negative healthy subjects (p<0.05). BCG vaccination and non-TB respiratory disease had little influence on the immunological responses of Rv2029c and Rv2628 proteins (p>0.05). The LTBI diagnostic performance of Rv2029c was higher than Rv2628 and Rv1813c by ROC evaluation. But Rv2628 had much higher specificity than Rv2029c in active TB patients and uninfected healthy subjects. The IgG level against Rv1813c was higher in the TB group than in LTBI and uninfected healthy subjects (p<0.05). These results suggest that T cell response to Rv2628 and antibody against Rv1813c might be applicable as biomarkers to distinguish TB from LTBI and uninfected individuals. PMID:26851588

  6. Molecular and pathologic insights from latent HIV-1 infection in the human brain

    PubMed Central

    Desplats, Paula; Dumaop, Wilmar; Smith, David; Adame, Anthony; Everall, Ian; Letendre, Scott; Ellis, Ronald; Cherner, Mariana; Grant, Igor

    2013-01-01

    Objective: We aimed to investigate whether HIV latency in the CNS might have adverse molecular, pathologic, and clinical consequences. Methods: This was a case-control comparison of HIV-1 seropositive (HIV+) patients with clinical and neuropathologic examination. Based on the levels of HIV-1 DNA, RNA, and p24 in the brain, cases were classified as controls, latent HIV CNS infection, and HIV encephalitis (HIVE). Analysis of epigenetic markers including BCL11B, neurodegeneration, and neuroinflammation was performed utilizing immunoblot, confocal microscopy, immunochemistry/image analysis, and qPCR. Detailed antemortem neurocognitive data were available for 23 out of the 32 cases. Results: HIV+ controls (n = 12) had no detectable HIV-1 DNA, RNA, or p24 in the CNS; latent HIV+ cases (n = 10) showed high levels of HIV-1 DNA but no HIV RNA or p24; and HIVE cases (n = 10) had high levels of HIV-1 DNA, RNA, and p24. Compared to HIV+ controls, the HIV+ latent cases displayed moderate cognitive impairment with neurodegenerative and neuroinflammatory alterations, although to a lesser extent than HIVE cases. Remarkably, HIV+ latent cases showed higher levels of BCL11B and other chromatin modifiers involved in silencing. Increased BCL11B was associated with deregulation of proinflammatory genes like interleukin-6, tumor necrosis factor–α, and CD74. Conclusion: Persistence of latent HIV-1 infection in the CNS was associated with increased levels of chromatin modifiers, including BCL11B. Alteration of these epigenetic factors might result in abnormal transcriptomes, leading to inflammation, neurodegeneration, and neurocognitive impairment. BCL11B and other epigenetic factors involved in silencing might represent potential targets for HIV-1 involvement of the CNS. PMID:23486877

  7. [Role of in vitro tests in the diagnosis of latent tubercular infections].

    PubMed

    Richeldi, Luca

    2010-01-01

    Recent advancements in the understanding of pathogenetic mechanisms in tuberculosis infection, allowed the identification of target molecules and antigens, playing a crucial role in an effective M. tuberculosis immune control. Thanks to this new information, the diagnostic approach to latent tuberculosis infection may be complemented today with two new blood assays, based on the detection and the quantification of the key cytokine interferon-gamma by peripheral blood T cells stimulated with M. tuberculosis-specific antigens. These new tests, QuantiFERON-TB Gold and T-SPOT.TB, being certainly more specific than the tuberculin skin test and probably more sensitive in some subgroups of patients, might represent a crucially relevant tool to achieve to goal of global tuberculosis control. Both assays have logistic advantages over the skin test, thus making them ideal candidates in situations where the tests need to be repeated over time (like in the setting of occupational medicine). In particular, the limited occurrence of the so-called "boosting" effect, the fact that there is no need for a return visit, the reduced variability in reading and reporting of the results and the quantitative response obtained with these assays are all elements that, altogether with the high specificity in BCG-vaccinated individuals, should favor the inclusion of these assays in the process of evaluation of the biologic risk for health care workers. Nonetheless, since these tests have been recently introduced in clinical practice, there are several aspects that still need to be clarified, such as the meaning of the quantitative responses and the interpretation of indeterminate results. It's therefore desirable that new documents will be produced soon to guide the use of these new tests in clinical routine. PMID:21061708

  8. High Levels of Epstein-Barr Virus DNA in Latently Infected Gastric Adenocarcinoma

    PubMed Central

    Ryan, Julie L.; Morgan, Douglas R.; Dominguez, Ricardo L.; Thorne, Leigh B.; Elmore, Sandra H.; Mino-Kenudson, Mari; Lauwers, Gregory Y.; Booker, Jessica K.; Gulley, Margaret L.

    2008-01-01

    Gastric adenocarcinoma is the second leading cause of cancer death worldwide. Epstein-Barr virus (EBV) is present in the malignant cells of approximately 10% of cases. It is unclear whether EBV is being missed in some gastric adenocarcinomas due to insensitive test methods or partial EBV genome loss. In the current study, we screened 113 gastric adenocarcinomas from low and high incidence regions (United States and Central America) for the presence of EBV using a battery quantitative real-time PCR (Q-PCR) assays targeting disparate segments of the EBV genome (BamH1W, EBNA1, LMP1, LMP2, BZLF1, EBER1) and histochemical stains targeting EBV-encoded RNA (EBER), the latent proteins LMP1 and LMP2, and the lytic proteins BMRF1 and BZLF1. EBV DNA was detected by Q-PCR in 48/75 United States cancers (64%) and in 38/38 Central American cancers (100%), which was a significant differrence. EBER was localized to malignant epithelial cells in 8/48 (17%) United States and 3/38 (8%) Central American cancers. Viral loads were considerably higher for EBER-positive versus EBER-negative cancers (mean 162,986 versus 62 EBV DNA copies per 100,000 cells). A viral load of 2,000 copies per 100,000 cells is recommended as the threshold distinguishing EBER-positive from EBER-negative tumors. One infected cancer selectively failed to amplify the LMP2 gene because of a point mutation, while another cancer had an atypical pattern of Q-PCR positivity suggesting deletion of large segments of the EBV genome. Three different viral latency profiles were observed in the cancers based on constant expression of EBER and focal or variable expression of LMP1 or LMP2, without lytic protein expression. We conclude that EBV DNA levels generally reflect EBER status, and a panel of at least two Q-PCR assays is recommended for sensitive identification of infected cancers. PMID:19002111

  9. Reactivation of latent herpes simplex virus infection by ultraviolet light: a human model

    SciTech Connect

    Perna, J.J.; Mannix, M.L.; Rooney, J.F.; Notkins, A.L.; Straus, S.E.

    1987-09-01

    Infection with herpes simplex virus often results in a latent infection of local sensory ganglia and a disease characterized by periodic viral reactivation and mucocutaneous lesions. The factors that trigger reactivation in humans are still poorly defined. In our study, five patients with documented histories of recurrent herpes simplex virus infection on the buttocks or sacrum were exposed to three times their minimal erythema dose of ultraviolet light. Site-specific cutaneous herpes simplex virus infection occurred at 4.4 +/- 0.4 days after exposure to ultraviolet light in 8 of 13 attempts at reactivation. We conclude that ultraviolet light can reactivate herpes simplex virus under experimentally defined conditions. This model in humans should prove useful in evaluating the pathophysiology and prevention of viral reactivation.

  10. Type II Toxoplasma gondii KU80 knockout strains enable functional analysis of genes required for cyst development and latent infection.

    PubMed

    Fox, Barbara A; Falla, Alejandra; Rommereim, Leah M; Tomita, Tadakimi; Gigley, Jason P; Mercier, Corinne; Cesbron-Delauw, Marie-France; Weiss, Louis M; Bzik, David J

    2011-09-01

    Type II Toxoplasma gondii KU80 knockouts (Δku80) deficient in nonhomologous end joining were developed to delete the dominant pathway mediating random integration of targeting episomes. Gene targeting frequency in the type II Δku80 Δhxgprt strain measured at the orotate (OPRT) and the uracil (UPRT) phosphoribosyltransferase loci was highly efficient. To assess the potential of the type II Δku80 Δhxgprt strain to examine gene function affecting cyst biology and latent stages of infection, we targeted the deletion of four parasite antigen genes (GRA4, GRA6, ROP7, and tgd057) that encode characterized CD8(+) T cell epitopes that elicit corresponding antigen-specific CD8(+) T cell populations associated with control of infection. Cyst development in these type II mutant strains was not found to be strictly dependent on antigen-specific CD8(+) T cell host responses. In contrast, a significant biological role was revealed for the dense granule proteins GRA4 and GRA6 in cyst development since brain tissue cyst burdens were drastically reduced specifically in mutant strains with GRA4 and/or GRA6 deleted. Complementation of the Δgra4 and Δgra6 mutant strains using a functional allele of the deleted GRA coding region placed under the control of the endogenous UPRT locus was found to significantly restore brain cyst burdens. These results reveal that GRA proteins play a functional role in establishing cyst burdens and latent infection. Collectively, our results suggest that a type II Δku80 Δhxgprt genetic background enables a higher-throughput functional analysis of the parasite genome to reveal fundamental aspects of parasite biology controlling virulence, pathogenesis, and transmission. PMID:21531875

  11. Antagonistic Determinants Controlling Replicative and Latent States of Human Cytomegalovirus Infection

    PubMed Central

    Umashankar, Mahadevaiah; Rak, Michael; Bughio, Farah; Zagallo, Patricia; Caviness, Katie

    2014-01-01

    ABSTRACT The mechanisms by which viruses persist and particularly those by which viruses actively contribute to their own latency have been elusive. Here we report the existence of opposing functions encoded by genes within a polycistronic locus of the human cytomegalovirus (HCMV) genome that regulate cell type-dependent viral fates: replication and latency. The locus, referred to as the UL133-UL138 (UL133/8) locus, encodes four proteins, pUL133, pUL135, pUL136, and pUL138. As part of the ULb′ region of the genome, the UL133/8 locus is lost upon serial passage of clinical strains of HCMV in cultured fibroblasts and is therefore considered dispensable for replication in this context. Strikingly, we could not reconstitute infection in permissive fibroblasts from bacterial artificial chromosome clones of the HCMV genome where UL135 alone was disrupted. The loss of UL135 resulted in complex phenotypes and could ultimately be overcome by infection at high multiplicities. The requirement for UL135 but not the entire locus led us to hypothesize that another gene in this locus suppressed virus replication in the absence of UL135. The defect associated with the loss of UL135 was largely rescued by the additional disruption of the UL138 latency determinant, indicating a requirement for UL135 for virus replication when UL138 is expressed. In the CD34+ hematopoietic progenitor model of latency, viruses lacking only UL135 were defective for viral genome amplification and reactivation. Taken together, these data indicate that UL135 and UL138 comprise a molecular switch whereby UL135 is required to overcome UL138-mediated suppression of virus replication to balance states of latency and reactivation. IMPORTANCE Mechanisms by which viruses persist in their host remain one of the most poorly understood phenomena in virology. Herpesviruses, including HCMV, persist in an incurable, latent state that has profound implications for immunocompromised individuals, including transplant

  12. Hit-and-Run Stimulation: a Novel Concept To Reactivate Latent HIV-1 Infection without Cytokine Gene Induction▿

    PubMed Central

    Wolschendorf, Frank; Duverger, Alexandra; Jones, Jennifer; Wagner, Frederic H.; Huff, Jason; Benjamin, William H.; Saag, Michael S.; Niederweis, Michael; Kutsch, Olaf

    2010-01-01

    Current antiretroviral therapy (ART) efficiently controls HIV-1 replication but fails to eradicate the virus. Even after years of successful ART, HIV-1 can conceal itself in a latent state in long-lived CD4+ memory T cells. From this latent reservoir, HIV-1 rebounds during treatment interruptions. Attempts to therapeutically eradicate this viral reservoir have yielded disappointing results. A major problem with previously utilized activating agents is that at the concentrations required for efficient HIV-1 reactivation, these stimuli trigger high-level cytokine gene expression (hypercytokinemia). Therapeutically relevant HIV-1-reactivating agents will have to trigger HIV-1 reactivation without the induction of cytokine expression. We present here a proof-of-principle study showing that this is a possibility. In a high-throughput screening effort, we identified an HIV-1-reactivating protein factor (HRF) secreted by the nonpathogenic bacterium Massilia timonae. In primary T cells and T-cell lines, HRF triggered a high but nonsustained peak of nuclear factor kappa B (NF-κB) activity. While this short NF-κB peak potently reactivated latent HIV-1 infection, it failed to induce gene expression of several proinflammatory NF-κB-dependent cellular genes, such as those for tumor necrosis factor alpha (TNF-α), interleukin-8 (IL-8), and gamma interferon (IFN-γ). Dissociation of cellular and viral gene induction was achievable, as minimum amounts of Tat protein, synthesized following application of a short NF-κB pulse, triggered HIV-1 transactivation and subsequent self-perpetuated HIV-1 expression. In the absence of such a positive feedback mechanism, cellular gene expression was not sustained, suggesting that strategies modulating the NF-κB activity profile could be used to selectively trigger HIV-1 reactivation. PMID:20538859

  13. Hit-and-run stimulation: a novel concept to reactivate latent HIV-1 infection without cytokine gene induction.

    PubMed

    Wolschendorf, Frank; Duverger, Alexandra; Jones, Jennifer; Wagner, Frederic H; Huff, Jason; Benjamin, William H; Saag, Michael S; Niederweis, Michael; Kutsch, Olaf

    2010-09-01

    Current antiretroviral therapy (ART) efficiently controls HIV-1 replication but fails to eradicate the virus. Even after years of successful ART, HIV-1 can conceal itself in a latent state in long-lived CD4(+) memory T cells. From this latent reservoir, HIV-1 rebounds during treatment interruptions. Attempts to therapeutically eradicate this viral reservoir have yielded disappointing results. A major problem with previously utilized activating agents is that at the concentrations required for efficient HIV-1 reactivation, these stimuli trigger high-level cytokine gene expression (hypercytokinemia). Therapeutically relevant HIV-1-reactivating agents will have to trigger HIV-1 reactivation without the induction of cytokine expression. We present here a proof-of-principle study showing that this is a possibility. In a high-throughput screening effort, we identified an HIV-1-reactivating protein factor (HRF) secreted by the nonpathogenic bacterium Massilia timonae. In primary T cells and T-cell lines, HRF triggered a high but nonsustained peak of nuclear factor kappa B (NF-kappaB) activity. While this short NF-kappaB peak potently reactivated latent HIV-1 infection, it failed to induce gene expression of several proinflammatory NF-kappaB-dependent cellular genes, such as those for tumor necrosis factor alpha (TNF-alpha), interleukin-8 (IL-8), and gamma interferon (IFN-gamma). Dissociation of cellular and viral gene induction was achievable, as minimum amounts of Tat protein, synthesized following application of a short NF-kappaB pulse, triggered HIV-1 transactivation and subsequent self-perpetuated HIV-1 expression. In the absence of such a positive feedback mechanism, cellular gene expression was not sustained, suggesting that strategies modulating the NF-kappaB activity profile could be used to selectively trigger HIV-1 reactivation. PMID:20538859

  14. Latent Mycobacterium tuberculosis Infection in Liver Transplant Recipients—Controversies in Current Diagnosis and Management

    PubMed Central

    Rajagopala, Srinivas; Olithselvan, A; Varghese, Joy; Shanmugam, Naresh; Rela, Mohamed

    2011-01-01

    Liver transplantation for end-stage liver disease is increasingly being undertaken in India.1 Routine tuberculin skin testing (TST) for latent Mycobacterium tuberculosis infection (LTBI) and isoniazid prophylaxis in TST-positive liver-transplant recipients (LTRs) is recommended2,3 but seldom implemented worldwide.4–7 The role of TST-testing and isoniazid prophylaxis in LTRs remains further undefined in high prevalence areas, including India. We describe the burden of LTBI in LTRs; the epidemiological aspects of M. tuberculosis infection in high prevalence areas; identifiable risk factors for M. tuberculosis infection; the limitations of current diagnostic techniques for LTBI in LTRs and the efficacy and toxicity of isoniazid prophylaxis in TST-positive LTRs and suggest directions for future investigations in this area. PMID:25755308

  15. Cruzipain Activates Latent TGF-β from Host Cells during T. cruzi Invasion.

    PubMed

    Ferrão, Patrícia Mello; d'Avila-Levy, Claudia Masini; Araujo-Jorge, Tania Cremonini; Degrave, Wim Maurits; Gonçalves, Antônio da Silva; Garzoni, Luciana Ribeiro; Lima, Ana Paula; Feige, Jean Jacques; Bailly, Sabine; Mendonça-Lima, Leila; Waghabi, Mariana Caldas

    2015-01-01

    Several studies indicate that the activity of cruzipain, the main lysosomal cysteine peptidase of Trypanosoma cruzi, contributes to parasite infectivity. In addition, the parasitic invasion process of mammalian host cells is described to be dependent on the activation of the host TGF-β signaling pathway by T. cruzi. Here, we tested the hypothesis that cruzipain could be an important activator of latent TGF-β and thereby trigger TGF-β-mediated events crucial for the development of Chagas disease. We found that live epimastigotes of T. cruzi, parasite lysates and purified cruzipain were able to activate latent TGF-β in vitro. This activation could be inhibited by the cysteine peptidase inhibitor Z-Phe-Ala-FMK. Moreover, transfected parasites overexpressing chagasin, a potent endogenous cruzipain inhibitor, prevented latent TGF-β activation. We also observed that T. cruzi invasion, as well as parasite intracellular growth, were inhibited by the administration of Z-Phe-Ala-FMK or anti-TGF-β neutralizing antibody to Vero cell cultures. We further demonstrated that addition of purified cruzipain enhanced the invasive activity of trypomastigotes and that this effect could be completely inhibited by addition of a neutralizing anti-TGF-β antibody. Taken together, these results demonstrate that the activities of cruzipain and TGF-β in the process of cell invasion are functionally linked. Our data suggest that cruzipain inhibition is an interesting chemotherapeutic approach for Chagas disease not only because of its trypanocidal activity, but also due to the inhibitory effect on TGF-β activation. PMID:25938232

  16. Cruzipain Activates Latent TGF-β from Host Cells during T. cruzi Invasion

    PubMed Central

    Ferrão, Patrícia Mello; d'Avila-Levy, Claudia Masini; Araujo-Jorge, Tania Cremonini; Degrave, Wim Maurits; Gonçalves, Antônio da Silva; Garzoni, Luciana Ribeiro; Lima, Ana Paula; Feige, Jean Jacques; Bailly, Sabine; Mendonça-Lima, Leila; Waghabi, Mariana Caldas

    2015-01-01

    Several studies indicate that the activity of cruzipain, the main lysosomal cysteine peptidase of Trypanosoma cruzi, contributes to parasite infectivity. In addition, the parasitic invasion process of mammalian host cells is described to be dependent on the activation of the host TGF-β signaling pathway by T. cruzi. Here, we tested the hypothesis that cruzipain could be an important activator of latent TGF-β and thereby trigger TGF-β-mediated events crucial for the development of Chagas disease. We found that live epimastigotes of T. cruzi, parasite lysates and purified cruzipain were able to activate latent TGF-β in vitro. This activation could be inhibited by the cysteine peptidase inhibitor Z-Phe-Ala-FMK. Moreover, transfected parasites overexpressing chagasin, a potent endogenous cruzipain inhibitor, prevented latent TGF-β activation. We also observed that T. cruzi invasion, as well as parasite intracellular growth, were inhibited by the administration of Z-Phe-Ala-FMK or anti-TGF-β neutralizing antibody to Vero cell cultures. We further demonstrated that addition of purified cruzipain enhanced the invasive activity of trypomastigotes and that this effect could be completely inhibited by addition of a neutralizing anti-TGF-β antibody. Taken together, these results demonstrate that the activities of cruzipain and TGF-β in the process of cell invasion are functionally linked. Our data suggest that cruzipain inhibition is an interesting chemotherapeutic approach for Chagas disease not only because of its trypanocidal activity, but also due to the inhibitory effect on TGF-β activation. PMID:25938232

  17. Latent Tuberculosis Infection and Associated Factors among Health Care Workers in Kigali, Rwanda

    PubMed Central

    Rutanga, Claude; Lowrance, David W.; Oeltmann, John E.; Mutembayire, Grace; Willis, Matt; Uwizeye, Claude Bernard; Hinda, Ruton; Bassirou, Chitou; Gutreuter, Steve; Gasana, Michel

    2015-01-01

    Introduction Data are limited regarding tuberculosis (TB) and latent TB infection prevalence in Rwandan health facilities. Methods We conducted a cross-sectional survey among healthcare workers (HCWs) in Kigali during 2010. We purposively selected the public referral hospital, both district hospitals, and randomly selected 7 of 17 health centers. School workers (SWs) from the nearest willing public schools served as a local reference group. We tested for latent TB infection (LTBI) using tuberculin skin testing (TST) and asked about past TB disease. We assessed risk of LTBI and past history of TB disease associated with hospital employment. Among HCWs, we assessed risk associated with facility type (district hospital, referral hospital, health center), work setting (inpatient, outpatient), and occupation. Results Age, gender, and HIV status was similar between the enrolled 1,131 HCWs and 381 SWs. LTBI was more prevalent among HCWs (62%) than SWs (39%). Adjusted odds of a positive TST result were 2.71 (95% CI 2.01–3.67) times greater among HCWs than SWs. Among HCWs, there was no detectable difference between prevalence of LTBI according to facility type, work setting, or occupation. Conclusion HCWs are at greater risk of LTBI, regardless of facility type, work setting, or occupation. The current status of TB infection control practices should be evaluated in the entire workforce in all Rwandan healthcare facilities. PMID:25919759

  18. Isolation of Mycobacterium kumamotonense from a patient with pulmonary infection and latent tuberculosis.

    PubMed

    Kontos, Fanourios; Mavromanolakis, Dimitrios Nikitas; Zande, Marina Chari; Gitti, Zoe Georgios

    2016-01-01

    Mycobacterium kumamotonense is a novel, slow-growing non-chromogenic nontuberculous mycobacterium, which belongs to Mycobacterium terrae complex. We report, for the first time in Greece, the isolation of M. kumamotonense from an immunocompetent patient with pulmonary infection and latent tuberculosis. M. kumamotonense was identified by sequencing analysis of 16S rDNA and 65-kDa heat shock protein genes while by commercial molecular assays it was misidentified as Mycobacterium celatum. Antibiotic susceptibility testing was performed by the reference broth microdilution method. The strain was susceptible to amikacin, clarithromycin, rifampin, ciprofloxacin, moxifloxacin, rifabutin, ethambutol and linezolid. PMID:27080783

  19. Directly Infected Resting CD4+T Cells Can Produce HIV Gag without Spreading Infection in a Model of HIV Latency

    PubMed Central

    Pace, Matthew J.; Graf, Erin H.; Agosto, Luis M.; Mexas, Angela M.; Male, Frances; Brady, Troy; Bushman, Frederic D.; O'Doherty, Una

    2012-01-01

    Despite the effectiveness of highly active antiretroviral therapy (HAART) in treating individuals infected with HIV, HAART is not a cure. A latent reservoir, composed mainly of resting CD4+T cells, drives viral rebound once therapy is stopped. Understanding the formation and maintenance of latently infected cells could provide clues to eradicating this reservoir. However, there have been discrepancies regarding the susceptibility of resting cells to HIV infection in vitro and in vivo. As we have previously shown that resting CD4+T cells are susceptible to HIV integration, we asked whether these cells were capable of producing viral proteins and if so, why resting cells were incapable of supporting productive infection. To answer this question, we spinoculated resting CD4+T cells with or without prior stimulation, and measured integration, transcription, and translation of viral proteins. We found that resting cells were capable of producing HIV Gag without supporting spreading infection. This block corresponded with low HIV envelope levels both at the level of protein and RNA and was not an artifact of spinoculation. The defect was reversed upon stimulation with IL-7 or CD3/28 beads. Thus, a population of latent cells can produce viral proteins without resulting in spreading infection. These results have implications for therapies targeting the latent reservoir and suggest that some latent cells could be cleared by a robust immune response. PMID:22911005

  20. Mycobacterium tuberculosis-specific CD4(+) T-cell response is increased, and Treg cells decreased, in anthelmintic-treated patients with latent TB.

    PubMed

    Toulza, Frederic; Tsang, Lillian; Ottenhoff, Tom H M; Brown, Michael; Dockrell, Hazel M

    2016-03-01

    In many settings, adults with active or latent tuberculosis will also be coinfected with helminths. Our study aimed to investigate how anthelmintic treatment modulates antimycobacterial immunity, in a setting where helminth reinfection should not occur. We investigated the potential impact of helminth infection on immune responses to Mycobacterium tuberculosis (Mtb) in patients with latent Mtb infection with or without helminth infection (Strongyloides or Schistosoma), and tested T-cell responses before and after anthelmintic treatment. The study was performed in migrants resident in the United Kingdom, where reexposure and reinfection following anthelmintic treatment would not occur. The frequency of CD4(+) IFN-γ(+) T cells was measured following stimulation with Mtb Purified Protein Derivative or ESAT-6/CFP-10 antigen, and concentrations of IFN-γ in culture supernatants measured by ELISA and multiplex bead array. Helminth infection was associated with a lower frequency of CD4(+) IFN-γ(+) T cells, which increased following treatment. Patients with helminth infection showed a significant increase in CD4(+) FoxP3(+) T cells (Treg) compared to those without helminth infection. There was a decrease in the frequency of Treg cells, and an associated increase in CD4(+) IFN-γ(+) T cells after the anthelmintic treatment. Here, we show a potential role of Treg cells in reducing the frequency and function of antimycobacterial CD4(+) IFN-γ(+) T cells, and that these effects are reversed after anthelmintic treatment. PMID:26638865

  1. Aminolevulinic acid (ALA)-assisted photodynamic diagnosis of subclinical and latent HPV infection of external genital region.

    PubMed

    Wang, Hong-Wei; Wang, Xiu-Li; Zhang, Ling-Lin; Guo, Ming-Xia; Huang, Zheng

    2008-12-01

    The relatively high recurrence rate of genital warts can be attributed to the unsuccessful elimination of viruses in areas of subclinical and latent infection. Therefore, the identification and treatment of the subclinical and latent infection is a key to reduce the recurrence. The goal of this study is to investigate the usefulness of 5-aminolevulinic acid (ALA)-assisted in situ fluorescence diagnosis of subclinical lesion and latent HPV infection. A total of 30 patients with histologically confirmed genital warts (condylomata acuminata) were subjected to topical application of ALA, acetic acid test, histopathologic examination and HPV DNA subtyping. Topical application of ALA was performed by applying 20% ALA cream to the lesion plus 2-cm margin for 2h followed by fluorescence examination. Correlations between histopathologic examination, aceto-whitening test, HPV DNA subtyping and fluorescence were examined. All warty lesions and subclinical lesions (n=25) showed red fluorescence and harbored HPV DNA (HPV6 or 11). Latent HPV infections at 0.5-2 cm away from the warty lesion also showed red fluorescence. Nonspecific fluorescence was associated with mucosa, inflammatory infiltration and erosive lesion. ALA-assisted photodynamic diagnosis could be employed for the detection of the lesion and subclinical lesion of genital warts. It is also useful in detecting latent HPV infection. PMID:19356665

  2. Epstein-Barr Viruses (EBVs) Deficient in EBV-Encoded RNAs Have Higher Levels of Latent Membrane Protein 2 RNA Expression in Lymphoblastoid Cell Lines and Efficiently Establish Persistent Infections in Humanized Mice

    PubMed Central

    Gregorovic, Goran; Boulden, Elizabeth A.; Bosshard, Rachel; Elgueta Karstegl, Claudio; Skalsky, Rebecca; Cullen, Bryan R.; Gujer, Cornelia; Rämer, Patrick; Münz, Christian

    2015-01-01

    Functions of Epstein-Barr virus (EBV)-encoded RNAs (EBERs) were tested in lymphoblastoid cell lines containing EBER mutants of EBV. Binding of EBER1 to ribosomal protein L22 (RPL22) was confirmed. Deletion of EBER1 or EBER2 correlated with increased levels of cytoplasmic EBV LMP2 RNA and with small effects on specific cellular microRNA (miRNA) levels, but protein levels of LMP1 and LMP2A were not affected. Wild-type EBV and EBER deletion EBV had approximately equal abilities to infect immunodeficient mice reconstituted with a human hematopoietic system. PMID:26339045

  3. Epstein-Barr Viruses (EBVs) Deficient in EBV-Encoded RNAs Have Higher Levels of Latent Membrane Protein 2 RNA Expression in Lymphoblastoid Cell Lines and Efficiently Establish Persistent Infections in Humanized Mice.

    PubMed

    Gregorovic, Goran; Boulden, Elizabeth A; Bosshard, Rachel; Elgueta Karstegl, Claudio; Skalsky, Rebecca; Cullen, Bryan R; Gujer, Cornelia; Rämer, Patrick; Münz, Christian; Farrell, Paul J

    2015-11-01

    Functions of Epstein-Barr virus (EBV)-encoded RNAs (EBERs) were tested in lymphoblastoid cell lines containing EBER mutants of EBV. Binding of EBER1 to ribosomal protein L22 (RPL22) was confirmed. Deletion of EBER1 or EBER2 correlated with increased levels of cytoplasmic EBV LMP2 RNA and with small effects on specific cellular microRNA (miRNA) levels, but protein levels of LMP1 and LMP2A were not affected. Wild-type EBV and EBER deletion EBV had approximately equal abilities to infect immunodeficient mice reconstituted with a human hematopoietic system. PMID:26339045

  4. Language discordance and testing for latent tuberculosis infection among recent Asian and Latino immigrants.

    PubMed

    Leng, Jennifer C F; Changrani, Jyotsna; Gany, Francesca M

    2011-04-01

    The foreign-born population is disproportionately affected by tuberculosis (TB). Testing to identify persons with latent TB infection is critical. The aim of this study was to assess clinic-based testing for latent tuberculosis infection among recent Asian and Latino immigrants. A randomized controlled trial of interpreting methods and their impact on medical outcomes was conducted at the primary care clinic of a New York City municipal hospital. This study is a nested cohort of recruited patients with an indication to receive tuberculin testing, based on recent migration to the US from endemic areas. Medical record data were abstracted to determine referral for, and completion of, tuberculin testing. Bivariate analyses were used to test for differences in tuberculin testing between language concordant and discordant groups. Seven hundred and eighty-two patients were enrolled. One hundred and ninety-one had migrated within 5 years of enrollment from endemic areas. None spoke English as a primary language. Seventy percentage of patient-provider encounters were language discordant. Seventeen of 191 were referred for testing. Fifteen (88%) completed testing. Six (40%) had positive results. There were no significant differences between language concordant and discordant patients. In this at-risk population, every patient in clinical care should be considered for testing if indicated by country of origin. PMID:20697787

  5. The emergence of latent infection in the early evolution of Mycobacterium tuberculosis.

    PubMed

    Chisholm, Rebecca H; Tanaka, Mark M

    2016-05-25

    Mycobacterium tuberculosis has an unusual natural history in that the vast majority of its human hosts enter a latent state that is both non-infectious and devoid of any symptoms of disease. From the pathogen perspective, it seems counterproductive to relinquish reproductive opportunities to achieve a détente with the host immune response. However, a small fraction of latent infections reactivate to the disease state. Thus, latency has been argued to provide a safe harbour for future infections which optimizes the persistence of M. tuberculosis in human populations. Yet, if a pathogen begins interactions with humans as an active disease without latency, how could it begin to evolve latency properties without incurring an immediate reproductive disadvantage? We address this question with a mathematical model. Results suggest that the emergence of tuberculosis latency may have been enabled by a mechanism akin to cryptic genetic variation in that detrimental latency properties were hidden from natural selection until their expression became evolutionarily favoured. PMID:27194699

  6. Brief Report: Prevalence of Latent Rheumatic Heart Disease Among HIV-Infected Children in Kampala, Uganda.

    PubMed

    Gleason, Brigette; Mirembe, Grace; Namuyonga, Judith; Okello, Emmy; Lwabi, Peter; Lubega, Irene; Lubega, Sulaiman; Musiime, Victor; Kityo, Cissy; Salata, Robert A; Longenecker, Chris T

    2016-02-01

    Rheumatic heart disease (RHD) remains highly prevalent in resource-constrained settings around the world, including countries with high rates of HIV/AIDS. Although both are immune-mediated diseases, it is unknown whether HIV modifies the risk or progression of RHD. We performed screening echocardiography to determine the prevalence of latent RHD in 488 HIV-infected children aged 5-18 in Kampala, Uganda. The overall prevalence of borderline/definite RHD was 0.82% (95% confidence interval: 0.26% to 2.23%), which is lower than the published prevalence rates of 1.5%-4% among Ugandan children. There may be protective factors that decrease the risk of RHD in HIV-infected children. PMID:26413847

  7. Association of autophagy-related IRGM polymorphisms with latent versus active tuberculosis infection in a Chinese population.

    PubMed

    Lu, Yanjun; Li, Qian; Peng, Jing; Zhu, Yaowu; Wang, Feng; Wang, Chunyu; Wang, Xiong

    2016-03-01

    The autophagy-related immunity-related GTPase family M protein, IRGM, plays an important role in the defense against tuberculosis (TB) infection. IRGM polymorphisms are associated with TB infection susceptibility, and recent studies demonstrate host genetic differences between active and latent TB. Here, we investigated the association between IRGM polymorphisms and TB infection type in a Chinese population. We recruited 268 and 321 patients with confirmed or latent TB, respectively, and 475 TB-free healthy controls. Three single nucleotide polymorphisms, rs10065172, rs10051924, and rs13361189 within IRGM were genotyped using TaqMan-based assays. Interferon-gamma release levels were tested by T-SPOT. rs10065172 (P = 0.024, OR 0.67 (95% CI 0.48-0.95)), rs10051924 (P = 0.01, OR 0.64 (95% CI 0.46-0.90)), and rs13361189 (P = 0.055, OR 0.72 (95% CI 0.51-1.01)) were associated with a protective role against latent TB progression. Haplotype analysis showed that TCC was protective for latent TB (P = 0.022, OR 0.74 (95% CI 0.57-0.96)) whereas TTC conferred a higher risk of active TB. Additionally, patients with the rs10065172 TT genotype had a higher response to TB specific antigens. Thus, IRGM polymorphism differences between latent and active TB suggests that genetic differences in autophagy might partly affect host TB infection status. PMID:26980495

  8. Whole genome sequencing of Mycobacterium tuberculosis reveals slow growth and low mutation rates during latent infections in humans.

    PubMed

    Colangeli, Roberto; Arcus, Vic L; Cursons, Ray T; Ruthe, Ali; Karalus, Noel; Coley, Kathy; Manning, Shannon D; Kim, Soyeon; Marchiano, Emily; Alland, David

    2014-01-01

    Very little is known about the growth and mutation rates of Mycobacterium tuberculosis during latent infection in humans. However, studies in rhesus macaques have suggested that latent infections have mutation rates that are higher than that observed during active tuberculosis disease. Elevated mutation rates are presumed risk factors for the development of drug resistance. Therefore, the investigation of mutation rates during human latency is of high importance. We performed whole genome mutation analysis of M. tuberculosis isolates from a multi-decade tuberculosis outbreak of the New Zealand Rangipo strain. We used epidemiological and phylogenetic analysis to identify four cases of tuberculosis acquired from the same index case. Two of the tuberculosis cases occurred within two years of exposure and were classified as recently transmitted tuberculosis. Two other cases occurred more than 20 years after exposure and were classified as reactivation of latent M. tuberculosis infections. Mutation rates were compared between the two recently transmitted pairs versus the two latent pairs. Mean mutation rates assuming 20 hour generation times were 5.5 X 10(-10) mutations/bp/generation for recently transmitted tuberculosis and 7.3 X 10(-11) mutations/bp/generation for latent tuberculosis. Generation time versus mutation rate curves were also significantly higher for recently transmitted tuberculosis across all replication rates (p = 0.006). Assuming identical replication and mutation rates among all isolates in the final two years before disease reactivation, the u 20 hr mutation rate attributable to the remaining latent period was 1.6 × 10(-11) mutations/bp/generation, or approximately 30 fold less than that calculated during the two years immediately before disease. Mutations attributable to oxidative stress as might be caused by bacterial exposure to the host immune system were not increased in latent infections. In conclusion, we did not find any evidence to suggest

  9. Whole Genome Sequencing of Mycobacterium tuberculosis Reveals Slow Growth and Low Mutation Rates during Latent Infections in Humans

    PubMed Central

    Colangeli, Roberto; Arcus, Vic L.; Cursons, Ray T.; Ruthe, Ali; Karalus, Noel; Coley, Kathy; Manning, Shannon D.; Kim, Soyeon; Marchiano, Emily; Alland, David

    2014-01-01

    Very little is known about the growth and mutation rates of Mycobacterium tuberculosis during latent infection in humans. However, studies in rhesus macaques have suggested that latent infections have mutation rates that are higher than that observed during active tuberculosis disease. Elevated mutation rates are presumed risk factors for the development of drug resistance. Therefore, the investigation of mutation rates during human latency is of high importance. We performed whole genome mutation analysis of M. tuberculosis isolates from a multi-decade tuberculosis outbreak of the New Zealand Rangipo strain. We used epidemiological and phylogenetic analysis to identify four cases of tuberculosis acquired from the same index case. Two of the tuberculosis cases occurred within two years of exposure and were classified as recently transmitted tuberculosis. Two other cases occurred more than 20 years after exposure and were classified as reactivation of latent M. tuberculosis infections. Mutation rates were compared between the two recently transmitted pairs versus the two latent pairs. Mean mutation rates assuming 20 hour generation times were 5.5X10−10 mutations/bp/generation for recently transmitted tuberculosis and 7.3X10−11 mutations/bp/generation for latent tuberculosis. Generation time versus mutation rate curves were also significantly higher for recently transmitted tuberculosis across all replication rates (p = 0.006). Assuming identical replication and mutation rates among all isolates in the final two years before disease reactivation, the u20hr mutation rate attributable to the remaining latent period was 1.6×10−11 mutations/bp/generation, or approximately 30 fold less than that calculated during the two years immediately before disease. Mutations attributable to oxidative stress as might be caused by bacterial exposure to the host immune system were not increased in latent infections. In conclusion, we did not find any evidence to suggest

  10. Testing for latent tuberculosis infection using interferon gamma release assays in commercial sex workers at an outreach clinic in Birmingham.

    PubMed

    Daly, R; Khatib, N; Larkins, A; Dedicoat, M

    2016-07-01

    This report demonstrates that using interferon gamma release assays to screen for latent tuberculosis infection in female commercial sex workers in an outreach sexual health clinic is feasible and acceptable. Routine interferon gamma release assay use successfully identified high numbers of latent tuberculosis infection. Innovative approaches to treatment and follow up were required to improve treatment adherence in this group. Direct observation of therapy within the sexual health clinic was also feasible. Successful follow up was dependent on the support of outreach workers, interpreters and tuberculosis nurses. PMID:26589629

  11. Identification of cytotoxic T cell epitopes within Epstein-Barr virus (EBV) oncogene latent membrane protein 1 (LMP1): evidence for HLA A2 supertype-restricted immune recognition of EBV-infected cells by LMP1-specific cytotoxic T lymphocytes.

    PubMed

    Khanna, R; Burrows, S R; Nicholls, J; Poulsen, L M

    1998-02-01

    Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) and latent membrane proteins (LMP) are the only antigens consistently expressed in malignancies such as nasopharyngeal carcinoma (NPC) and Hodgkin's disease (HD). Since EBNA1 is not recognized by EBV-specific cytotoxic T lymphocytes (CTL), there is increasing interest in the identification of the potential target epitopes within LMP1. Although LMP1-specific CTL have been isolated from seropositive individuals, earlier attempts to identify the peptide epitopes recognized by these T cells have been unsuccessful. In the present report we used a novel protocol to identify CTL epitopes within LMP1 which can be recognized by both polyclonal and clonal CTL. Firstly, a computer-based program was employed to identify the potential HLA-binding peptides within LMP1. Polyclonal CD8+ CTL were then isolated from seropositive donors that recognized the peptide epitopes YLLEMLWRL and YLQQNWWTL from LMP1 in association with HLA A2. Limiting dilution analysis of the memory CTL response revealed that the LMP1-specific CTL response constitutes a minor component of the CTL response in healthy virus carriers. Interestingly, analysis of YLLEMLWRL-specific CTL revealed that these CTL were able to lyse EBV-infected B cells expressing different HLA A2 supertype alleles including A*0201, A*0202, A*0203, A*0204, A*0206, A*6802 and A*6901. These data strongly support the notion that HLA class I supertype-restricted CTL may be of significant use in the development of peptide-based immunotherapeutics against EBV-associated malignancies in different ethnic populations. PMID:9521052

  12. β-Catenin, a Transcription Factor Activated by Canonical Wnt Signaling, Is Expressed in Sensory Neurons of Calves Latently Infected with Bovine Herpesvirus 1

    PubMed Central

    Liu, Yilin; Hancock, Morgan; Workman, Aspen; Doster, Alan

    2016-01-01

    ABSTRACT Like many Alphaherpesvirinae subfamily members, bovine herpesvirus 1 (BoHV-1) expresses an abundant transcript in latently infected sensory neurons, the latency-related (LR)-RNA. LR-RNA encodes a protein (ORF2) that inhibits apoptosis, interacts with Notch family members, interferes with Notch-mediated transcription, and stimulates neurite formation in cells expressing Notch. An LR mutant virus containing stop codons at the amino terminus of ORF2 does not reactivate from latency or replicate efficiently in certain tissues, indicating that LR gene products are important. In this study, β-catenin, a transcription factor activated by the canonical Wnt signaling pathway, was frequently detected in ORF2-positive trigeminal ganglionic neurons of latently infected, but not mock-infected, calves. Conversely, the lytic cycle regulatory protein (BoHV-1 infected cell protein 0, or bICP0) was not frequently detected in β-catenin-positive neurons in latently infected calves. During dexamethasone-induced reactivation from latency, mRNA expression levels of two Wnt antagonists, Dickkopf-1 (DKK-1) and secreted Frizzled-related protein 2 (SFRP2), were induced in bovine trigeminal ganglia (TG), which correlated with reduced β-catenin protein expression in TG neurons 6 h after dexamethasone treatment. ORF2 and a coactivator of β-catenin, mastermind-like protein 1 (MAML1), stabilized β-catenin protein levels and stimulated β-catenin-dependent transcription in mouse neuroblastoma cells more effectively than MAML1 or ORF2 alone. Neuroblastoma cells expressing ORF2, MAML1, and β-catenin were highly resistant to cell death following serum withdrawal, whereas most cells transfected with only one of these genes died. The Wnt signaling pathway interferes with neurodegeneration but promotes neuronal differentiation, suggesting that stabilization of β-catenin expression by ORF2 promotes neuronal survival and differentiation. IMPORTANCE Bovine herpesvirus 1 (BoHV-1) is an

  13. Bifurcation in Disease Dynamics with Latent Period of Infection and Media Awareness

    NASA Astrophysics Data System (ADS)

    Singh, Harkaran; Dhar, Joydip; Bhatti, Harbax Singh

    2016-06-01

    In the present study, an SIS epidemic model with a latent period of infection and media awareness as control strategy is proposed. The asymptotic stability of the model is studied for both disease-free equilibrium and endemic equilibrium states with respect to the basic reproduction number R0. It is observed that the coefficient of media awareness m does not affect R0, but significantly affects the level of endemic equilibrium. Further, the specific conditions for the existence of Hopf bifurcation have been obtained for the endemic equilibrium state. We also performed the sensitivity analysis of the basic reproduction number and state variables at endemic steady state with respect to the model parameter and identified the respective sensitive parameters. Numerical simulations have been presented in support of our analytic findings.

  14. TRANSMISSION AND RISK FACTORS FOR LATENT TUBERCULOSIS INFECTIONS AMONG INDEX CASE-MATCHED HOUSEHOLD CONTACTS.

    PubMed

    Faksri, Kiatichai; Reechaipichitkul, Wipa; Pimrin, Wilailuk; Bourpoern, Janpen; Prompinij, Supapim

    2015-05-01

    An understanding of the risk factors associated with acquiring and transmitting Mycobacterium tuberculosis (MTB) is required for controlling tuberculosis (TB). We aimed to determine the risk factors and transmission factors for latent tuberculosis infection (LTBI) in northeastern Thailand. Household contact persons (n = 70) and matched index patients with pulmonary TB (n = 42) who presented to Srinagarind Hospital, Khon Kaen, Thailand were interviewed from September 1, 2012 to March 31, 2014. LTBI was determined by positive results on both a tuberculin skin test and the QuantiFERON-TB Gold In-Tube test. Multivariate analysis of host and environmental risk factors was performed. Among contact persons, being aged 20 years (adjusted OR=14.0; 95% CI: 1.2-159.5), having a family relationship with a TB subject such as being a spouse or parent (adjusted OR=24.9; 95% CI: 2.4-263.9) and exposure to a TB subject for 5 hours/day (adjusted OR=9.2; 95% CI: 1.4-58.1) were risk factors for LTBI. Having a high bacillary load (adjusted OR=2; 95% CI: 1.26-3.17) or a moderate bacillary load (adjusted OR=1.39; 95% CI: 1.04-1.84) among TB subjects correlated with increased transmissibility compared to having a low bacillary load. The type of dwelling and density of household members were not found to be risk factors for LTBI in our study. We conclude being aged 20 years and having a relationship with a TB patient as a spouse or parent were risk factors for acquiring LTBI, and having a higher bacillary load was a risk factor for transmitting TB. Keywords: latent tuberculosis infection, transmission factor, risk factor, Mycobacterium tuberculosis, interferon-gamma release assay, Thailand PMID:26521523

  15. Prevalence of tuberculosis symptoms and latent tuberculous infection among prisoners in northeastern Malaysia

    PubMed Central

    Margolis, B.; Al-Darraji, H. A. A.; Wickersham, J. A.; Kamarulzaman, A.; Altice, F. L.

    2014-01-01

    SUMMARY SETTING There are currently no routine screening procedures for active tuberculosis (TB) or latent tuberculous infection (LTBI) in Malaysian prisons. OBJECTIVE To determine the prevalence and correlates of LTBI and active TB symptoms among Malaysian prisoners with and without human immunodeficiency virus (HIV) infection using the tuberculin skin test (TST) and the World Health Organization TB symptom-based screening instrument. DESIGN A cross-sectional survey of 266 prisoners was performed in Kelantan, Malaysia. Consenting participants underwent two-step TST and were screened for active TB symptoms. Standardized cut-offs of respectively ≥5 and ≥10 mm were used to define reactive TST among prisoners with and without HIV. Clinical and behavioral data were assessed and HIV-infected prisoners were stratified by CD4 status. RESULTS Overall LTBI prevalence was 87.6%, with significantly lower TST reactivity among HIV-infected than non-HIV-infected prisoners (83.6% vs. 91.5%, P < 0.05); however, TB symptoms were similar (16.9% vs. 10.1%, P = 0.105). On multivariate analysis, previous incarceration (aOR 4.61, 95%CI 1.76–12.1) was the only significant correlate of LTBI. Increasing age (aOR 1.07, 95%CI 1.01–1.13), lower body mass index (aOR 0.82, 95%CI 0.70–0.96) and TST-reactive status (aOR 3.46, 95%CI 1.20–9.97) were correlated with TB symptoms. CONCLUSION LTBI is highly prevalent, associated with previous incarceration, and suggests the need for routine TB screening on entry to Malaysian prisons. PMID:24200265

  16. Sensitivity of IFN-γ Release Assay to Detect Latent Tuberculosis Infection Is Retained in HIV-Infected Patients but Dependent on HIV/AIDS Progression

    PubMed Central

    Karam, Farba; Mbow, Fatou; Fletcher, Helen; Senghor, Cheikh S.; Coulibaly, Koura D.; LeFevre, Andrea M.; Ngom Gueye, Ndeye F.; Dieye, Tandakha; Sow, Papa S.; Mboup, Souleymane; Lienhardt, Christian

    2008-01-01

    Background Detection and treatment of latent TB infection (LTBI) in HIV infected individuals is strongly recommended to decrease morbidity and mortality in countries with high levels of HIV. Objective To assess the validity of a newly developed in-house ELISPOT interferon-γ release assay (IGRA) for the detection of LTBI amongst HIV infected individuals, in comparison with the Tuberculin Skin Test (TST). Methodology/Principal Findings ESAT6/CFP10 (EC) ELISPOT assays were performed, together with a TST, in 285 HIV infected individuals recruited in HIV clinics in Dakar, Senegal, who had no signs of active TB at time of enrolment. Thirty eight of the subjects (13.3%) failed to respond to PHA stimulation and were excluded from the analysis. In the 247 remaining patients, response to PHA did not vary according to CD4 cell count categories (p = 0.51). EC ELISPOT was positive in 125 (50.6%) subjects, while 53 (21.5%) had a positive TST. Concordance between EC ELISPOT and TST was observed in 151 patients (61.1%) (kappa = 0.23). The proportion of subjects with a positive response to the EC ELISPOT assay decreased with declining CD4 counts (p trend = 0.001), but were consistently higher than the proportion of TST responders. In multivariate analysis, the risk of being EC-ELISPOT positive in HIV infected individuals was associated with age, CD4 count and HIV-1 strain. Conclusion Our study indicates that IGRAs using M. tuberculosis specific antigens are likely to retain their validity for the diagnosis of LTBI among HIV positive individuals, but may be impaired by T-cell anergy in severely immuno-suppressed individuals. PMID:18197251

  17. Trypanosome-induced Interferon-γ production in whole blood stimulation assays is associated with latent Trypanosoma brucei gambiense infections.

    PubMed

    Ilboudo, Hamidou; Jamonneau, Vincent; Koffi, Mathurin; Kaboré, Jacques; Amoussa, Roukiyath; Holzmuller, Philippe; Garcia, André; Bucheton, Bruno; Courtin, David

    2016-06-01

    Control of human African trypanosomiasis (HAT) is highly dependent on the ability to detect and treat infected individuals. However, a number of individuals exposed to Trypanosoma brucei gambiense are able to control infection to undetectable levels in blood. They are long-term potential reservoirs and thus a threat for control strategies. Cytokine responses in whole blood stimulation assays were quantified in individuals with contrasting HAT status. Trypanosome-induced IFN-γ production was only observed in "trypanotolerant" subjects suspected of harboring latent infections. This result contributes new insights into the immune responses associated with infection control and opens novel diagnosis perspectives regarding HAT elimination. PMID:26993030

  18. Characterization of Host and Microbial Determinants in Individuals with Latent Tuberculosis Infection Using a Human Granuloma Model

    PubMed Central

    Guirado, Evelyn; Mbawuike, Uchenna; Keiser, Tracy L.; Arcos, Jesus; Azad, Abul K.; Wang, Shu-Hua

    2015-01-01

    ABSTRACT Granulomas sit at the center of tuberculosis (TB) immunopathogenesis. Progress in biomarkers and treatment specific to the human granuloma environment is hindered by the lack of a relevant and tractable infection model that better accounts for the complexity of the host immune response as well as pathogen counterresponses that subvert host immunity in granulomas. Here we developed and characterized an in vitro granuloma model derived from human peripheral blood mononuclear cells (PBMCs) and autologous serum. Importantly, we interrogated this model for its ability to discriminate between host and bacterial determinants in individuals with and without latent TB infection (LTBI). By the use of this model, we provide the first evidence that granuloma formation, bacterial survival, lymphocyte proliferation, pro- and anti-inflammatory cytokines, and lipid body accumulation are significantly altered in LTBI individuals. Moreover, we show a specific transcriptional signature of Mycobacterium tuberculosis associated with survival within human granuloma structures depending on the host immune status. Our report provides fundamentally new information on how the human host immune status and bacterial transcriptional signature may dictate early granuloma formation and outcome and provides evidence for the validity of the granuloma model and its potential applications. PMID:25691598

  19. Management of latent Mycobacterium tuberculosis infection: WHO guidelines for low tuberculosis burden countries.

    PubMed

    Getahun, Haileyesus; Matteelli, Alberto; Abubakar, Ibrahim; Aziz, Mohamed Abdel; Baddeley, Annabel; Barreira, Draurio; Den Boon, Saskia; Borroto Gutierrez, Susana Marta; Bruchfeld, Judith; Burhan, Erlina; Cavalcante, Solange; Cedillos, Rolando; Chaisson, Richard; Chee, Cynthia Bin-Eng; Chesire, Lucy; Corbett, Elizabeth; Dara, Masoud; Denholm, Justin; de Vries, Gerard; Falzon, Dennis; Ford, Nathan; Gale-Rowe, Margaret; Gilpin, Chris; Girardi, Enrico; Go, Un-Yeong; Govindasamy, Darshini; D Grant, Alison; Grzemska, Malgorzata; Harris, Ross; Horsburgh, C Robert; Ismayilov, Asker; Jaramillo, Ernesto; Kik, Sandra; Kranzer, Katharina; Lienhardt, Christian; LoBue, Philip; Lönnroth, Knut; Marks, Guy; Menzies, Dick; Migliori, Giovanni Battista; Mosca, Davide; Mukadi, Ya Diul; Mwinga, Alwyn; Nelson, Lisa; Nishikiori, Nobuyuki; Oordt-Speets, Anouk; Rangaka, Molebogeng Xheedha; Reis, Andreas; Rotz, Lisa; Sandgren, Andreas; Sañé Schepisi, Monica; Schünemann, Holger J; Sharma, Surender Kumar; Sotgiu, Giovanni; Stagg, Helen R; Sterling, Timothy R; Tayeb, Tamara; Uplekar, Mukund; van der Werf, Marieke J; Vandevelde, Wim; van Kessel, Femke; van't Hoog, Anna; Varma, Jay K; Vezhnina, Natalia; Voniatis, Constantia; Vonk Noordegraaf-Schouten, Marije; Weil, Diana; Weyer, Karin; Wilkinson, Robert John; Yoshiyama, Takashi; Zellweger, Jean Pierre; Raviglione, Mario

    2015-12-01

    Latent tuberculosis infection (LTBI) is characterised by the presence of immune responses to previously acquired Mycobacterium tuberculosis infection without clinical evidence of active tuberculosis (TB). Here we report evidence-based guidelines from the World Health Organization for a public health approach to the management of LTBI in high risk individuals in countries with high or middle upper income and TB incidence of <100 per 100 000 per year. The guidelines strongly recommend systematic testing and treatment of LTBI in people living with HIV, adult and child contacts of pulmonary TB cases, patients initiating anti-tumour necrosis factor treatment, patients receiving dialysis, patients preparing for organ or haematological transplantation, and patients with silicosis. In prisoners, healthcare workers, immigrants from high TB burden countries, homeless persons and illicit drug users, systematic testing and treatment of LTBI is conditionally recommended, according to TB epidemiology and resource availability. Either commercial interferon-gamma release assays or Mantoux tuberculin skin testing could be used to test for LTBI. Chest radiography should be performed before LTBI treatment to rule out active TB disease. Recommended treatment regimens for LTBI include: 6 or 9 month isoniazid; 12 week rifapentine plus isoniazid; 3-4 month isoniazid plus rifampicin; or 3-4 month rifampicin alone. PMID:26405286

  20. Management of latent Mycobacterium tuberculosis infection: WHO guidelines for low tuberculosis burden countries

    PubMed Central

    Matteelli, Alberto; Abubakar, Ibrahim; Aziz, Mohamed Abdel; Baddeley, Annabel; Barreira, Draurio; Den Boon, Saskia; Borroto Gutierrez, Susana Marta; Bruchfeld, Judith; Burhan, Erlina; Cavalcante, Solange; Cedillos, Rolando; Chaisson, Richard; Chee, Cynthia Bin-Eng; Chesire, Lucy; Corbett, Elizabeth; Dara, Masoud; Denholm, Justin; de Vries, Gerard; Falzon, Dennis; Ford, Nathan; Gale-Rowe, Margaret; Gilpin, Chris; Girardi, Enrico; Go, Un-Yeong; Govindasamy, Darshini; D. Grant, Alison; Grzemska, Malgorzata; Harris, Ross; Horsburgh Jr, C. Robert; Ismayilov, Asker; Jaramillo, Ernesto; Kik, Sandra; Kranzer, Katharina; Lienhardt, Christian; LoBue, Philip; Lönnroth, Knut; Marks, Guy; Menzies, Dick; Migliori, Giovanni Battista; Mosca, Davide; Mukadi, Ya Diul; Mwinga, Alwyn; Nelson, Lisa; Nishikiori, Nobuyuki; Oordt-Speets, Anouk; Rangaka, Molebogeng Xheedha; Reis, Andreas; Rotz, Lisa; Sandgren, Andreas; Sañé Schepisi, Monica; Schünemann, Holger J.; Sharma, Surender Kumar; Sotgiu, Giovanni; Stagg, Helen R.; Sterling, Timothy R.; Tayeb, Tamara; Uplekar, Mukund; van der Werf, Marieke J.; Vandevelde, Wim; van Kessel, Femke; van't Hoog, Anna; Varma, Jay K.; Vezhnina, Natalia; Voniatis, Constantia; Vonk Noordegraaf-Schouten, Marije; Weil, Diana; Weyer, Karin; Wilkinson, Robert John; Yoshiyama, Takashi; Zellweger, Jean Pierre; Raviglione, Mario

    2015-01-01

    Latent tuberculosis infection (LTBI) is characterised by the presence of immune responses to previously acquired Mycobacterium tuberculosis infection without clinical evidence of active tuberculosis (TB). Here we report evidence-based guidelines from the World Health Organization for a public health approach to the management of LTBI in high risk individuals in countries with high or middle upper income and TB incidence of <100 per 100 000 per year. The guidelines strongly recommend systematic testing and treatment of LTBI in people living with HIV, adult and child contacts of pulmonary TB cases, patients initiating anti-tumour necrosis factor treatment, patients receiving dialysis, patients preparing for organ or haematological transplantation, and patients with silicosis. In prisoners, healthcare workers, immigrants from high TB burden countries, homeless persons and illicit drug users, systematic testing and treatment of LTBI is conditionally recommended, according to TB epidemiology and resource availability. Either commercial interferon-gamma release assays or Mantoux tuberculin skin testing could be used to test for LTBI. Chest radiography should be performed before LTBI treatment to rule out active TB disease. Recommended treatment regimens for LTBI include: 6 or 9 month isoniazid; 12 week rifapentine plus isoniazid; 3–4 month isoniazid plus rifampicin; or 3–4 month rifampicin alone. PMID:26405286

  1. Latent cytomegalovirus infection exacerbates experimental pulmonary fibrosis by activating TGF-β1.

    PubMed

    Li, Yonghuai; Gao, Jian; Wang, Guoliang; Fei, Guanghe

    2016-08-01

    The aim of the present study was to investigate the hypotheses that cytomegalovirus (CMV) may trigger idiopathic pulmonary fibrosis (IPF) in a susceptible host and/or that the presence of CMV may alter IPF in response to a well-defined trigger of pulmonary fibrosis. A mouse model of murine CMV (MCMV) infection was established, and the mice were divided into a control group, bleomycin group and an MCMV+bleomycin group. Changes in the weights of the mice were determined in the three groups. Pulmonary fibrosis was detected using a histopathological method. The activity of transforming growth factor (TGF)‑β1 was measured, and the levels of E‑cadherin, Vimentin and phosphorylated (phospho)‑small mothers against decapentaplegic (SMAD)2 were determined using western blot analysis. MCMV was found to invade the lungs, however, it did not cause pulmonary fibrosis. The progression of fibrosis in the mice treated with MCMV+bleomycin was more rapid, compared with that in the control mice. The protein levels of Vimentin and phospho-SMAD2 were upregulated, whereas the level of E‑cadherin was downregulated in the MCMV+bleomycin group,. The results suggested that latent MCMV infection aggravated pulmonary fibrosis in the mouse model, possibly through the activation of TGF-β1. PMID:27279470

  2. HIV-1 Vpr Protein Induces Proteasomal Degradation of Chromatin-associated Class I HDACs to Overcome Latent Infection of Macrophages.

    PubMed

    Romani, Bizhan; Baygloo, Nima Shaykh; Hamidi-Fard, Mojtaba; Aghasadeghi, Mohammad Reza; Allahbakhshi, Elham

    2016-02-01

    Mechanisms underlying HIV-1 latency remain among the most crucial questions that need to be answered to adopt strategies for purging the latent viral reservoirs. Here we show that HIV-1 accessory protein Vpr induces depletion of class I HDACs, including HDAC1, 2, 3, and 8, to overcome latency in macrophages. We found that Vpr binds and depletes chromatin-associated class I HDACs through a VprBP-dependent mechanism, with HDAC3 as the most affected class I HDAC. De novo expression of Vpr in infected macrophages induced depletion of HDAC1 and 3 on the HIV-1 LTR that was associated with hyperacetylation of histones on the HIV-1 LTR. As a result of hyperacetylation of histones on HIV-1 promotor, the virus established an active promotor and this contributed to the acute infection of macrophages. Collectively, HIV-1 Vpr down-regulates class I HDACs on chromatin to counteract latent infections of macrophages. PMID:26679995

  3. Latent tuberculosis infection in a Malaysian prison: implications for a comprehensive integrated control program in prisons

    PubMed Central

    2014-01-01

    Background Prisons continue to fuel tuberculosis (TB) epidemics particularly in settings where access to TB screening and prevention services is limited. Malaysia is a middle-income country with a relatively high incarceration rate of 138 per 100,000 population. Despite national TB incidence rate remaining unchanged over the past ten years, data about TB in prisons and its contribution to the overall national rates does not exist. This survey was conducted to address the prevalence of latent TB infection (LTBI) in Malaysia’s largest prison. Methods From July to December 2010, all HIV-infected and a comparative group of HIV-uninfected prisoners housed separately in Kajang prison were asked to participate in the survey after explaining the study protocol. Subjects providing informed consent were interviewed using a structured questionnaire followed by the placement of tuberculin skin test (TST) with 2 TU of PPD RT-23 to subjects not being treated for active TB. TST was read after 48-72 hours and indurations of ≥ 5 mm and ≥ 10 mm were considered positive among HIV-infected and HIV-uninfected subjects, respectively. Additionally, HIV-infected inmates underwent phlebotomy for CD4 lymphocyte count assessment. A logistic regression model was explored to determine factors associated with TST positivity. Results Overall, 286 subjects (138 HIV-infected and 148 HIV-uninfected) had complete data and TST results. The majority were men (95.1%), less than 40 years old (median age 36.0, SD 7.87), and Malaysians (93.3%). Most (82.5%) had been previously incarcerated and more than half (53.1%) reported sharing needles just prior to their incarceration. TST was positive in 88.8% (84.7% among HIV-infected and 92.5% among HIV-uninfected subjects) and was independently associated with being HIV-uninfected (AOR = 2.97, p = 0.01) and with frequent previous incarcerations (AOR = 1.22 for every one previous incarceration, p = 0.01) after adjusting for other

  4. Eligibility for and outcome of treatment of latent tuberculosis infection in a cohort of HIV-infected people in Spain

    PubMed Central

    2010-01-01

    Background Previous studies have demonstrated the efficacy of treatment for latent tuberculosis infection (TLTBI) in persons infected with the human immunodeficiency virus, but few studies have investigated the operational aspects of implementing TLTBI in the co-infected population.The study objectives were to describe eligibility for TLTBI as well as treatment prescription, initiation and completion in an HIV-infected Spanish cohort and to investigate factors associated with treatment completion. Methods Subjects were prospectively identified between 2000 and 2003 at ten HIV hospital-based clinics in Spain. Data were obtained from clinical records. Associations were measured using the odds ratio (OR) and its 95% confidence interval (95% CI). Results A total of 1242 subjects were recruited and 846 (68.1%) were evaluated for TLTBI. Of these, 181 (21.4%) were eligible for TLTBI either because they were tuberculin skin test (TST) positive (121) or because their TST was negative/unknown but they were known contacts of a TB case or had impaired immunity (60). Of the patients eligible for TLTBI, 122 (67.4%) initiated TLTBI: 99 (81.1%) were treated with isoniazid for 6, 9 or 12 months; and 23 (18.9%) with short-course regimens including rifampin plus isoniazid and/or pyrazinamide. In total, 70 patients (57.4%) completed treatment, 39 (32.0%) defaulted, 7 (5.7%) interrupted treatment due to adverse effects, 2 developed TB, 2 died, and 2 moved away. Treatment completion was associated with having acquired HIV infection through heterosexual sex as compared to intravenous drug use (OR:4.6; 95% CI:1.4-14.7) and with having taken rifampin and pyrazinamide for 2 months as compared to isoniazid for 9 months (OR:8.3; 95% CI:2.7-24.9). Conclusions A minority of HIV-infected patients eligible for TLTBI actually starts and completes a course of treatment. Obstacles to successful implementation of this intervention need to be addressed. PMID:20840743

  5. Epstein–Barr virus latent genes

    PubMed Central

    Kang, Myung-Soo; Kieff, Elliott

    2015-01-01

    Latent Epstein–Barr virus (EBV) infection has a substantial role in causing many human disorders. The persistence of these viral genomes in all malignant cells, yet with the expression of limited latent genes, is consistent with the notion that EBV latent genes are important for malignant cell growth. While the EBV-encoded nuclear antigen-1 (EBNA-1) and latent membrane protein-2A (LMP-2A) are critical, the EBNA-leader proteins, EBNA-2, EBNA-3A, EBNA-3C and LMP-1, are individually essential for in vitro transformation of primary B cells to lymphoblastoid cell lines. EBV-encoded RNAs and EBNA-3Bs are dispensable. In this review, the roles of EBV latent genes are summarized. PMID:25613728

  6. Latent Tuberculosis Infection Among Immigrant and Refugee Children Arriving in the United States: 2010.

    PubMed

    Taylor, Eboni M; Painter, John; Posey, Drew L; Zhou, Weigong; Shetty, Sharmila

    2016-10-01

    Immigrants and refugees age 2-14 years entering the United States from countries with estimated tuberculosis (TB) incidence rate ≥20 per 100,000 population are screened for TB. Children with TB disease are treated before US arrival. Children with positive tuberculin skin tests (TST), but negative TB evaluation during their pre-immigration examination, are classified with latent TB infection (LTBI) and are recommended for re-evaluation post-arrival. We examined post-immigration TB evaluation and therapy for children arriving with LTBI. We reviewed medical exam data from immigrant children with medical conditions and all refugee children arriving during 2010. Medical examination data were available for 67,334 children. Of these, 8231 (12 %) had LTBI pre-immigration; 5749 (70 %) were re-evaluated for TB post-immigration, and 64 % were retested by TST or IGRA. The pre-immigration LTBI diagnosis was changed for 38 % when retested by TST and for 71 % retested by IGRA. Estimated LTBI therapy initiation and completion rates were 68 and 12 %. In this population, testing with IGRA may limit the number of children targeted for therapy. Increased pre-immigration TB screening with post-immigration follow-up evaluation leading to completion of LTBI therapy should be encouraged to prevent TB reactivation. PMID:26364054

  7. Identifying components for programmatic latent tuberculosis infection control in the European Union.

    PubMed

    Sandgren, Andreas; Vonk Noordegraaf-Schouten, Jannigje M; Oordt-Speets, Anouk M; van Kessel, Gerarda B; de Vlas, Sake J; van der Werf, Marieke J

    2016-08-25

    Individuals with latent tuberculosis infection (LTBI) are the reservoir of Mycobacterium tuberculosis in a population and as long as this reservoir exists, elimination of tuberculosis (TB) will not be feasible. In 2013, the European Centre for Disease Prevention and Control (ECDC) started an assessment of benefits and risks of introducing programmatic LTBI control, with the aim of providing guidance on how to incorporate LTBI control into national TB strategies in European Union/European Economic Area (EU/EEA) Member States and candidate countries. In a first step, experts from the Member States, candidate countries, and international and national organisations were consulted on the components of programmatic LTBI control that should be considered and evaluated in literature reviews, mathematical models and cost-effectiveness studies. This was done through a questionnaire and two interactive discussion rounds. The main components identified were identification and targeting of risk groups, determinants of LTBI and progression to active TB, optimal diagnostic tests for LTBI, effective preventive treatment regimens, and to explore the potential for combining LTBI control with other health programmes. Political commitment, a solid healthcare infrastructure, and favourable economic situation in specific countries were identified as essential to facilitate the implementation of programmatic LTBI control. PMID:27589214

  8. Can Social History Variables Predict Prison Inmates' Risk for Latent Tuberculosis Infection?

    PubMed Central

    Weant, Tyler E.; Turner, Abigail Norris; Murphy-Weiss, Maureen; Murray, David M.; Wang, Shu-Hua

    2012-01-01

    Improved screening and treatment of latent tuberculosis infection (LTBI) in correctional facilities may improve TB control. The Ohio Department of Rehabilitation and Correction (ODRC) consists of 32 prisons. Inmates are screened upon entry to ODRC and yearly thereafter. The objective of the study was to determine if social history factors such as tobacco, alcohol, and drug use are significant predictors of LTBI and treatment outcomes. We reviewed the medical charts of inmates and randomly selected age-matched controls at one ODRC facility for 2009. We used a conditional logistic regression to assess associations between selected social history variables and LTBI diagnosis. Eighty-nine inmates with a history of LTBI and 88 controls were identified. No social history variable was a significant predictor of LTBI. Medical comorbidities such as asthma, rheumatoid arthritis, and hepatitis C were significantly higher in inmates with LTBI. 84% of inmates diagnosed with LTBI had either completed or were on treatment. Annual TB screening may not be cost-effective in all inmate populations. Identification of factors to help target screening populations at risk for TB is critical. Social history variables did not predict LTBI in our inmate population. Additional studies are needed to identify inmates for the targeted TB testing. PMID:23320160

  9. Knowledge and Perceptions of Latent Tuberculosis Infection among Chinese Immigrants in a Canadian Urban Centre

    PubMed Central

    Gao, Jie; Berry, Nicole S.; Taylor, Darlene; Venners, Scott A.; Cook, Victoria J.; Mayhew, Maureen

    2015-01-01

    Background. Since most tuberculosis (TB) cases in immigrants to British Columbia (BC), Canada, develop from latent TB infection (LTBI), treating immigrants for LTBI can contribute to the eradication of TB. However, adherence to LTBI treatment is a challenge that is influenced by knowledge and perceptions. This research explores Chinese immigrants' knowledge and perceptions towards LTBI in Greater Vancouver. Methods. This mixed methods study included a cross-sectional patient survey at BC's Provincial TB clinics and two focus group discussions (FGDs) with Chinese immigrants. Data from FGDs were coded and analyzed in Simplified Chinese. Codes, themes, and selected quotes were then translated into English. Results. The survey identified a mean basic knowledge score: 40.0% (95% CI: 38.3%, 41.7%). FGDs confirmed that Chinese immigrants' knowledge of LTBI was low, and they confused it with TB disease to the extent of experiencing LTBI associated stigma. Participants also expressed difficulties navigating the health system which impeded testing and treatment of LTBI. Online videos were the preferred format for receiving health information. Conclusion. We identified striking gaps in knowledge surrounding an LTBI diagnosis. Concerns of stigma may influence acceptance and adherence of LTBI treatment in Chinese immigrants. Integrating these findings into routine health care is recommended. PMID:26690263

  10. Prevalence of latent tuberculosis infection among health care workers in a hospital for pulmonary diseases

    PubMed Central

    Schablon, Anja; Beckmann, Gudrun; Harling, Melanie; Diel, Roland; Nienhaus, Albert

    2009-01-01

    Background Little is known about the prevalence of latent tuberculosis infections (LTBI) in health care workers (HCW) in low-incidence countries especially in hospitals for pulmonary diseases. With Interferon-gamma release assays (IGRA), a new method for diagnosis of LTBI is available which is more specific than the tuberculin skin test (TST). Objectives The study was designed to estimate prevalence of LTBI among 270 HCW in a Hospital of Pulmonary Diseases routinely screened for TB. Methods LTBI was assessed by the QuantiFERON-Gold In Tube (QFT-IT). Information on gender, age, workplace, job title, BCG vaccination and history of both TB and TST were collected using a standardised questionnaire. Adjusted odds ratios for potential risk factors for LTBI were calculated. Results The prevalence of LTBI was 7.2%. In HCW younger than 30 years LTBI prevalence was 3.5% and in those older than 50 years 22%. Physicians and nurses showed a higher prevalence rate than other professions (10.8% to 4.5%). The putative risk factors for LTBI were age (>50 year OR 9.3, 95%CI 2.5–33.7), working as physicians/nurses (OR 3. 95%CI 1.2–10.4) and no previous TST in medical history (OR 4.4, 95%CI 1.01–18.9) when compared to those with a negative TST. Conclusion Prevalence of LTBI assessed by QFT-IT is low, this indicates a low infection risk even in hospitals for pulmonary diseases. No statement can be made regarding the occupational risk as compared to the general population because there are no LTBI prevalence data from Germany available. The higher LTBI prevalence rate in older HCWs might be due to the cohort effect or the longer time at risk. PMID:19134168

  11. Modulation of pro- and anti-inflammatory cytokines in active and latent tuberculosis by coexistent Strongyloides stercoralis infection.

    PubMed

    George, Parakkal Jovvian; Pavan Kumar, Nathella; Jaganathan, Jeeva; Dolla, Chandrakumar; Kumaran, Paul; Nair, Dina; Banurekha, Vaithilingam V; Shen, Kui; Nutman, Thomas B; Babu, Subash

    2015-12-01

    Helminth infections are known to induce modulation of both innate and adaptive immune responses in active and latent tuberculosis (TB). However, the role of helminth infections in modulating systemic cytokine responses in active and latent tuberculosis (LTB) is not known. To define the systemic cytokine levels in helminth-TB coinfection, we measured the circulating plasma levels of Type 1, Type 2, Type 17, other pro-inflammatory and regulatory cytokines in individuals with active TB (ATB) with or without coexistent Strongyloides stercoralis (Ss) infection by multiplex ELISA. Similarly, we also measured the same cytokine levels in individuals with LTB with or without concomitant Ss infection in a cross-sectional study. Our data reveal that individuals with ATB or LTB and coexistent Ss infection have significantly lower levels of Type 1 (IFNγ, TNFα and IL-2) and Type 17 (IL-17A and IL-17F) cytokines compared to those without Ss infection. In contrast, those with ATB and LTB with Ss infection have significantly higher levels of the regulatory cytokines (IL-10 and TGFβ), and those with LTB and Ss infection also have significantly higher levels of Type 2 cytokines (IL-4, IL-5 and IL-13) as well. Finally, those with LTB (but not ATB) exhibit significantly lower levels of other pro-inflammatory cytokines (IFNα, IFNβ, IL-6, IL-12 and GM-CSF). Our data therefore reveal a profound effect of Ss infection on the systemic cytokine responses in ATB and LTB and indicate that coincident helminth infections might influence pathogenesis of TB infection and disease. PMID:26542223

  12. Mucosal and Parenteral Vaccination against Acute and Latent Murine Cytomegalovirus (MCMV) Infection by Using an Attenuated MCMV Mutant

    PubMed Central

    MacDonald, Margaret R.; Li, Xi-Yang; Stenberg, Richard M.; Campbell, Ann E.; Virgin, Herbert W.

    1998-01-01

    We used a live attenuated murine cytomegalovirus (MCMV) mutant to analyze mechanisms of vaccination against acute and latent CMV infection. We selected MCMV mutant RV7 as a vaccine candidate since this virus grows well in tissue culture but is profoundly attenuated for growth in normal and severe combined immunodeficient (SCID) mice (V. J. Cavanaugh et al., J. Virol. 70:1365–1374, 1996). BALB/c mice were immunized twice (0 and 14 days) subcutaneously (s.c.) with tissue culture-passaged RV7 and then challenged with salivary gland-passaged wild-type MCMV (sgMCMV) intraperitoneally (i.p.) on day 28. RV7 vaccination protected mice against challenge with 105 PFU of sgMCMV, a dose that killed 100% of mock-vaccinated mice. RV7 vaccination reduced MCMV replication 100- to 500-fold in the spleen between 1 and 8 days after challenge. We used the capacity to control replication of MCMV in the spleen 4 days after challenge as a surrogate for protection. Protection was antigen specific and required both live RV7 and antigen-specific lymphocytes. Interestingly, RV7 was effective when administered s.c., i.p., perorally, intranasally, and intragastrically, demonstrating that attenuated CMV applied to mucosal surfaces can elicit protection against parenteral virus challenge. B cells and immunoglobulin G were not essential for RV7-induced immunity since B-cell-deficient mice were effectively vaccinated by RV7. CD8 T cells, but not CD4 T cells, were critical for RV7-induced protection. Depletion of CD8 T cells by passive transfer of monoclonal anti-CD8 (but not anti-CD4) antibody abrogated RV7-mediated protection, and RV7 vaccination was less efficient in CD8 T-cell-deficient mice with a targeted mutation in the β2-microglobulin gene. Although gamma interferon is important for innate resistance to MCMV, it was not essential for RV7 vaccination since gamma interferon receptor-deficient mice were protected by RV7 vaccination. Establishment of and/or reactivation from latency by sg

  13. Differentially proteomic analysis of the Chinese shrimp at WSSV latent and acute infection stages by iTRAQ approach.

    PubMed

    Li, Shihao; Li, Fuhua; Sun, Zheng; Zhang, Xiaojun; Xiang, Jianhai

    2016-07-01

    As the direct executors of biological function, the expression level of proteins will reveal the molecular mechanisms regulating WSSV acute infection more directly. In the present study, the iTRAQ approach was applied to identifying differentially expressed proteins in Chinese shrimp during WSSV latent infection and acute infection. A total of 4051 unique peptides corresponding to 1286 proteins were identified. 118 unique proteins showed differential up-regulation and 122 proteins were down-regulated in shrimp during WSSV acute infection compared with those in WSSV latent infection stage. A number of proteins related to actin-myosin cytoskeleton process, including myosin, actin, tubulin, clathrin, and tropomyosin were found up-regulated in shrimp at WSSV AI stage, indicating that the phagocytosis process was involved in WSSV AI stage. The apoptosis process in shrimp during WSSV AI seemed to be inhibited because some proteins suppressive on apoptosis were up-regulated, such as ALG-2 interacting protein x, Hsp90, 14-3-3-like protein, peroxiredoxin 5, peroxiredoxin 6 and adenine nucleotide translocase 2. Association analysis between the proteomic data and the previous transcriptome data was performed. Quantitative real-time PCR and western blot were carried out to verify the reliability of the proteomics data. The present study provided a comprehensive view of molecular mechanisms regulating WSSV acute infection at the protein level. PMID:27192146

  14. An AP-1 binding site in the enhancer/core element of the HIV-1 promoter controls the ability of HIV-1 to establish latent infection.

    PubMed

    Duverger, Alexandra; Wolschendorf, Frank; Zhang, Mingce; Wagner, Fredric; Hatcher, Brandon; Jones, Jennifer; Cron, Randall Q; van der Sluis, Renee M; Jeeninga, Rienk E; Berkhout, Ben; Kutsch, Olaf

    2013-02-01

    Following integration, HIV-1 in most cases produces active infection events; however, in some rare instances, latent infection events are established. The latter have major clinical implications, as latent infection allows the virus to persist despite antiretroviral therapy. Both the cellular factors and the viral elements that potentially determine whether HIV-1 establishes active or latent infection events remain largely elusive. We detail here the contribution of different long terminal repeat (LTR) sequences for the establishment of latent HIV-1 infection. Using a panel of full-length replication-competent virus constructs that reflect naturally occurring differences of HIV-1 subtype-specific LTRs and targeted LTR mutants, we found the primary ability of HIV-1 to establish latent infection in this system to be controlled by a four-nucleotide (nt) AP-1 element just upstream of the NF-κB element in the viral promoter. Deletion of this AP-1 site mostly deprived HIV-1 of the ability to establish latent HIV-1 infection. Extension of this site to a 7-nt AP-1 sequence massively promoted latency establishment, suggesting that this promoter region represents a latency establishment element (LEE). Given that these minimal changes in a transcription factor binding site affect latency establishment to such large extent, our data support the notion that HIV-1 latency is a transcription factor restriction phenomenon. PMID:23236059

  15. An AP-1 Binding Site in the Enhancer/Core Element of the HIV-1 Promoter Controls the Ability of HIV-1 To Establish Latent Infection

    PubMed Central

    Duverger, Alexandra; Wolschendorf, Frank; Zhang, Mingce; Wagner, Fredric; Hatcher, Brandon; Jones, Jennifer; Cron, Randall Q.; van der Sluis, Renee M.; Jeeninga, Rienk E.; Berkhout, Ben

    2013-01-01

    Following integration, HIV-1 in most cases produces active infection events; however, in some rare instances, latent infection events are established. The latter have major clinical implications, as latent infection allows the virus to persist despite antiretroviral therapy. Both the cellular factors and the viral elements that potentially determine whether HIV-1 establishes active or latent infection events remain largely elusive. We detail here the contribution of different long terminal repeat (LTR) sequences for the establishment of latent HIV-1 infection. Using a panel of full-length replication-competent virus constructs that reflect naturally occurring differences of HIV-1 subtype-specific LTRs and targeted LTR mutants, we found the primary ability of HIV-1 to establish latent infection in this system to be controlled by a four-nucleotide (nt) AP-1 element just upstream of the NF-κB element in the viral promoter. Deletion of this AP-1 site mostly deprived HIV-1 of the ability to establish latent HIV-1 infection. Extension of this site to a 7-nt AP-1 sequence massively promoted latency establishment, suggesting that this promoter region represents a latency establishment element (LEE). Given that these minimal changes in a transcription factor binding site affect latency establishment to such large extent, our data support the notion that HIV-1 latency is a transcription factor restriction phenomenon. PMID:23236059

  16. Epstein-Barr virus latent membrane protein 2A is a B-cell receptor mimic and essential for B-cell survival

    PubMed Central

    Mancao, Christoph

    2007-01-01

    Many cells latently infected with Epstein-Barr virus (EBV), including certain virus-associated tumors, express latent membrane protein 2A (LMP2A), suggesting an important role for this protein in viral latency and oncogenesis. LMP2A mimics B-cell receptor signaling but can also act as a decoy receptor blocking B-cell receptor (BCR) activation. Studies of peripheral B cells have not resolved this apparent contradiction because LMP2A seems to be dispensable for EBV-induced transformation of these B cells in vitro. We show here that LMP2A is essential for growth transformation of germinal center B cells, which do not express the genuine BCR because of deleterious somatic hypermutations in their immunoglobulin genes. BCR-positive (BCR+) and BCR-negative (BCR−) B cells are readily transformed with a recombinant EBV encoding a conditional, floxed LMP2A allele, but the survival and continued proliferation of both BCR+ and BCR− B cells is strictly dependent on LMP2A. These findings indicate that LMP2A has potent, distinct antiapoptotic and/or transforming characteristics and point to its role as an indispensable BCR mimic in certain B cells from which human B-cell tumors such as Hodgkin lymphoma originate. PMID:17682125

  17. Adipose Tissue-Derived Mesenchymal Stem Cells as a New Host Cell in Latent Leishmaniasis

    PubMed Central

    Allahverdiyev, Adil M.; Bagirova, Melahat; Elcicek, Serhat; Koc, Rabia Cakir; Baydar, Serap Yesilkir; Findikli, Necati; Oztel, Olga N.

    2011-01-01

    Some protozoan infections such as Toxoplasma, Cryptosporidium, and Plasmodium can be transmitted through stem cell transplantations. To our knowledge, so far, there is no study about transmission of Leishmania parasites in stem cell transplantation and interactions between parasites and stem cells in vitro. Therefore, the aim of this study was to investigate the interaction between different species of Leishmania parasites and adipose tissue-derived mesenchymal stem cells (ADMSCs). ADMSCs have been isolated, cultured, characterized, and infected with different species of Leishmania parasites (L. donovani, L. major, L. tropica, and L. infantum). Infectivity was examined by Giemsa staining, microculture, and polymerase chain reaction methods. As a result, infectivity of ADMSCs by Leishmania parasites has been determined for the first time in this study. According to our findings, it is very important that donors are screened for Leishmania parasites before stem cell transplantations in regions where leishmaniasis is endemic. PMID:21896818

  18. Adipose tissue-derived mesenchymal stem cells as a new host cell in latent leishmaniasis.

    PubMed

    Allahverdiyev, Adil M; Bagirova, Melahat; Elcicek, Serhat; Koc, Rabia Cakir; Baydar, Serap Yesilkir; Findikli, Necati; Oztel, Olga N

    2011-09-01

    Some protozoan infections such as Toxoplasma, Cryptosporidium, and Plasmodium can be transmitted through stem cell transplantations. To our knowledge, so far, there is no study about transmission of Leishmania parasites in stem cell transplantation and interactions between parasites and stem cells in vitro. Therefore, the aim of this study was to investigate the interaction between different species of Leishmania parasites and adipose tissue-derived mesenchymal stem cells (ADMSCs). ADMSCs have been isolated, cultured, characterized, and infected with different species of Leishmania parasites (L. donovani, L. major, L. tropica, and L. infantum). Infectivity was examined by Giemsa staining, microculture, and polymerase chain reaction methods. As a result, infectivity of ADMSCs by Leishmania parasites has been determined for the first time in this study. According to our findings, it is very important that donors are screened for Leishmania parasites before stem cell transplantations in regions where leishmaniasis is endemic. PMID:21896818

  19. A Homogeneous Immunoassay Method for Detecting Interferon-Gamma in Patients with Latent Tuberculosis Infection.

    PubMed

    Wu, Fei; Wang, Lin; Guo, Qiaomei; Zhao, Mingna; Gu, Hongchen; Xu, Hong; Lou, Jiatao

    2016-03-28

    IFN-γ release assays (IGRAs) have been developed as viable alternative diagnostic tools for detecting latent tuberculosis infection (LTBI). A customized homogeneous sandwich luminescent oxygen channeling immunoassay (LOCI) was used to quantify IFN-γ levels in IGRAs. Samples were collected from healthy volunteers (n = 40) who were T-Spot-negative and T-Spot-positive patients (n = 32) at rest. Then the amount of IFN-γ in the supernatant of IGRAs was measured by LOCI. The results demonstrated a low background, and high sensitivity, specificity, accuracy, and reproducibility, and a short assay time (only 30 min) with LOCI for IFN-γ. The recovery range was 81.63-102.06%, the coefficients of variation were below 5%, and the limit of detection was 19.0 mIU/ml. Excellent agreement between LOCI IFN-γ and the T-SPOT.TB test was obtained (97.2% agreement, κ = 0.94). The LOCI IFN-γ concentrations were significantly higher in T-Spot-positive patients than in the healthy group (p < 0.001). Moreover, as observed for the comparative LOCI IFN-γ assay, IFN-γ concentrations were related to the numbers of T-SPOT.TB spots. We have established an in vitro blood test for LTBI diagnosis, defined as LOCI IFN-γ. A high level of agreement between the LOCI IFN-γ method and T-SPOT.TB assay was observed in clinical studies that showed the LOCI IFN-γ method could determine LTBI. This study shows acceptable performance characteristics of the LOCI IFN-γ assay to diagnose LTBI. PMID:26628252

  20. Gender Disparities in Latent Tuberculosis Infection in High-Risk Individuals: A Cross-Sectional Study

    PubMed Central

    Ting, Wen-Ying; Huang, Shiang-Fen; Lee, Ming-Che; Lin, Yung-Yang; Lee, Yu-Chin

    2014-01-01

    Male predominance in active tuberculosis (TB) is widely-reported globally. Gender inequalities in socio-cultural status are frequently regarded as contributing factors for disparities in sex in active TB. The disparities of sex in the prevalence of latent TB infection (LTBI) are less frequently investigated and deserve clarification. In this cross-sectional study conducted in a TB endemic area, we enrolled patients at high-risk for LTBI and progression from LTBI to active TB from 2011 to 2012. Diagnosis of LTBI was made by QuantiFERON-TB Gold In-Tube (QFT-GIT). Differences in sex in terms of prevalence of LTBI and clinical predictors for LTBI were investigated. Associations among age, smoking status, and sex disparities in LTBI were also analyzed. A total of 1018 high-risk individuals with definite QFT-GIT results were included for analysis, including 534 males and 484 females. The proportion of LTBI was significantly higher in males than in females (32.6% vs. 25.2%, p = 0.010). Differences in the proportion of LTBI between sexes were most prominent in older patients (age ≥55 years). In multivariate analysis, independent clinical factors associated with LTBI were age (p = 0.014), smoking (p = 0.048), and fibro-calcified lesions on chest radiogram (p = 0.009). Male sex was not an independent factor for LTBI (p = 0.88). When stratifying patients according to the smoking status, the proportion of LTBI remained comparable between sexes among smokers and non-smokers. In conclusion, although the proportion of LTBI is higher in men, there is no significant disparity in terms of sex in LTBI among high-risk individuals after adjusting for age, smoking status, and other clinical factors. PMID:25369472

  1. Dynamics of the resting CD4+ T-cell latent HIV reservoir in infants initiating HAART less than 6 months of age

    PubMed Central

    Persaud, Deborah; Palumbo, Paul E.; Ziemniak, Carrie; Hughes, Michael D.; Alvero, Carmelita G.; Luzuriaga, Katherine; Yogev, Ram; Capparelli, Edmund V.; Chadwick, Ellen G.

    2012-01-01

    Objectives Identification of HIV infection in exposed infants facilitates early therapy, which may limit viral reservoirs that maintain HIV infection under HAART. Methods The dynamics of the resting CD4+ T-cell latent HIV reservoir was determined over the first 2 years of life in 17 HIV-infected infants initiating lopinavir/ritonavir-based HAART at a median age of 8.1 weeks and achieving adequate suppression of plasma viral load by 24 weeks. Results The resting CD4+ T-cell latent HIV reservoir was detected in 12 of 14 (86%) infants tested at 24 weeks of HAART [median frequency 1.88 infectious units per million (IUPM); range <0.22 to 81.7), and remained measurable (median IUPM =0.32; range < 0.22 to 3.25) in six of 10 (60%) children retested at 96 weeks. The reservoir declined, from 24 to 96 weeks of HAART, at an estimated mean rate of 0.028 log10 IUPM/month, corresponding to a half-life of 11 months (95% confidence interval 6–30 months]. A strong relationship was found between the frequency of latently infected CD4+T cells at 96 weeks of HAART and time to first undetectable plasma viral load (Spearman r =0.91, P <0.001). Conclusion Although the resting CD4+ T-cell latent reservoir remains detectable over the first 2 years of HAART in a substantial proportion of infants, its size is associated with time to first undetectable viral load. To minimize HIV reservoirs in infants, rapid curtailment of viremia may limit HIV reservoirs and should be a therapeutic goal of early HAART in infants. PMID:22555165

  2. Diminished Systemic and Antigen-Specific Type 1, Type 17, and Other Proinflammatory Cytokines in Diabetic and Prediabetic Individuals With Latent Mycobacterium tuberculosis Infection

    PubMed Central

    Kumar, Nathella Pavan; George, Parakkal Jovvian; Kumaran, Paul; Dolla, Chandra Kumar; Nutman, Thomas B.; Babu, Subash

    2014-01-01

    Background. Diabetes mellitus type 2 (DM) is known to be a major risk factor for the development of active tuberculosis, although its influence on latent Mycobacterium tuberculosis infection (hereafter, “latent infection”) remains poorly characterized. Methods. We examined circulating plasma cytokine levels in individuals with latent infection with DM or pre-DM (ie, intermediate hyperglycemia) and compared them to levels in patients with latent infection and normal glycemic control. Results. In persons with DM or pre-DM, latent infection is characterized by diminished circulating levels of type 1 (interferon γ, interleukin 2, and tumor necrosis factor α) and type 17 (interleukin 17F) cytokines. This was associated with decreased systemic levels of other proinflammatory cytokines (interleukin 1β and interleukin 18) and the antiinflammatory cytokine interleukin 10 but not with decreased systemic levels of type 2 cytokines. Moreover, latently infected individuals with DM had diminished levels of spontaneous and M. tuberculosis antigen–specific levels of type 1 and type 17 cytokines when antigen-stimulated whole blood was examined. Finally, there was no significant correlation between the levels of any of the cytokines measured (with the exception of interleukin 22) with hemoglobin A1c levels. Conclusions. Our data reveal that latent infection in the presence of DM or pre-DM, is characterized by diminished production of cytokines, implicated in the control of M. tuberculosis activation, allowing for a potential immunological mechanism that could account for the increased risk of active tuberculosis in latently infected individuals with DM. PMID:24907382

  3. High frequency of latent Chlamydia trachomatis infection in patients with rhegmatogenous retinal detachment

    PubMed Central

    Boiko, Ernest V.; Pozniak, Alexei L.; Maltsev, Dmitrii S.; Suetov, Alexei A.; Nuralova, Irina V.

    2016-01-01

    AIM To determine the frequency of detection of ocular and extraocular Chlamydia trachomatis (CT) infection in non-high myopes with rhegmatogenous retinal detachment (RRD). METHODS This was a single-center, nonrandomized, prospective, case-control study. One hundred and four patients were divided into a study group with RRD (n=63) and a control group with traumatic retinal detachment (n=41). Samples of subretinal fluid (SFR), conjunctival, urethral/cervical swabs, and blood were collected. The frequency of detection of CT infection in SRF samples was determined by polymerase chain reaction (PCR), direct fluorescence assay (DFA) and cell culture, whereas that in conjunctival swabs was determined by PCR and DFA, and those in urethral/cervical swabs and blood were determined by DFA. Yates Chi-square test (with Bonferroni correction) and two-tailed Student's t-test were used for statistical analysis. RESULTS SRF CT infection was detected more frequently in the study group (50.8%-71.4%) than in the control group (9.8%-12.2%) by all the methods used (P<0.01). The frequency of detection of conjunctival CT infection by DFA was higher in the RRD patients compared with the controls (81.0% vs 24.4%, P=0.004). The PCR detected conjunctival CT infection more often in the study group than in the controls (46.0% vs 9.8%, P=0.007). The DFA detected CT in blood specimens almost as frequently as in urogenital specimens, for the RRD patients (61.2% vs 63.5%) and the controls (7.3% vs 9.8%). CONCLUSION CT infection is detected with high frequency in non-high myopes with RRD. PMID:27366689

  4. Type II Toxoplasma gondii KU80 Knockout Strains Enable Functional Analysis of Genes Required for Cyst Development and Latent Infection ▿ †

    PubMed Central

    Fox, Barbara A.; Falla, Alejandra; Rommereim, Leah M.; Tomita, Tadakimi; Gigley, Jason P.; Mercier, Corinne; Cesbron-Delauw, Marie-France; Weiss, Louis M.; Bzik, David J.

    2011-01-01

    Type II Toxoplasma gondii KU80 knockouts (Δku80) deficient in nonhomologous end joining were developed to delete the dominant pathway mediating random integration of targeting episomes. Gene targeting frequency in the type II Δku80 Δhxgprt strain measured at the orotate (OPRT) and the uracil (UPRT) phosphoribosyltransferase loci was highly efficient. To assess the potential of the type II Δku80 Δhxgprt strain to examine gene function affecting cyst biology and latent stages of infection, we targeted the deletion of four parasite antigen genes (GRA4, GRA6, ROP7, and tgd057) that encode characterized CD8+ T cell epitopes that elicit corresponding antigen-specific CD8+ T cell populations associated with control of infection. Cyst development in these type II mutant strains was not found to be strictly dependent on antigen-specific CD8+ T cell host responses. In contrast, a significant biological role was revealed for the dense granule proteins GRA4 and GRA6 in cyst development since brain tissue cyst burdens were drastically reduced specifically in mutant strains with GRA4 and/or GRA6 deleted. Complementation of the Δgra4 and Δgra6 mutant strains using a functional allele of the deleted GRA coding region placed under the control of the endogenous UPRT locus was found to significantly restore brain cyst burdens. These results reveal that GRA proteins play a functional role in establishing cyst burdens and latent infection. Collectively, our results suggest that a type II Δku80 Δhxgprt genetic background enables a higher-throughput functional analysis of the parasite genome to reveal fundamental aspects of parasite biology controlling virulence, pathogenesis, and transmission. PMID:21531875

  5. MUC1 induced by Epstein-Barr virus latent membrane protein 1 causes dissociation of the cell-matrix interaction and cellular invasiveness via STAT signaling.

    PubMed

    Kondo, Satoru; Yoshizaki, Tomokazu; Wakisaka, Naohiro; Horikawa, Toshiyuki; Murono, Shigeyuki; Jang, Kyung Lib; Joab, Irene; Furukawa, Mitsuru; Pagano, Joseph S

    2007-02-01

    Disruption of cellular adhesion is an essential pathobiologic step leading to tumor dissemination. Mucin 1 (MUC1) is a mucinous glycoprotein expressed at the surfaces of epithelial cells in many tissues and their carcinomas. MUC1 plays crucial roles in tumor invasion and metastasis, especially in opposing cell adhesion. We have shown that virus infection, specifically by the human tumor virus Epstein-Barr virus (EBV) induces a spectrum of cellular invasiveness and metastasis factors. Here we show that expression of MUC1 is increased in diverse latently EBV-infected cell lines that express latent membrane protein 1 (LMP1), the main viral oncoprotein, and that the level of MUC1 was suppressed by expression of a dominant-negative mutant of LMP1. Expression of LMP1 in EBV-negative nasopharyngeal cell lines induces expression of MUC1 through activation of the MUC1 promoter via binding of STAT1 and STAT3. Finally, LMP1 reduces cell adhesion ability, which is restored by inhibition of MUC1 expression with MUC1 small interfering RNA (siRNA). In addition, LMP1 increases cell invasiveness, which is suppressed by MUC1 siRNA. Thus, LMP1 induces MUC1, a factor important in an early step of detachment and release of tumor cells, which along with induction of other invasiveness and angiogenic factors may combine to act in a complex sequential process that culminates in metastasis of EBV-infected tumor cells. PMID:17151127

  6. Induction of apoptosis accelerates reactivation of latent HSV-1 in ganglionic organ cultures and replication in cell cultures

    PubMed Central

    Du, Te; Zhou, Guoying; Roizman, Bernard

    2012-01-01

    Herpes simplex viruses replicate at the portal of entry into the body and are transported retrograde to sensory neurons in which they can establish a silent, latent infection characterized by the expression of a noncoding latency-associated transcript and a set of microRNAs. At the portal of entry into the body and in cell culture a viral protein, VP16, recruits cellular proteins that initiate a sequential derepression of several kinetic classes of viral genes. Earlier studies have shown that upon reactivation of latent virus in ganglionic organ cultures all genes are derepressed at once, thus obviating the need for VP16 to initiate sequential derepression of viral genes. One hypothesis that could explain the data is that the massive reactivation of all classes of viral genes is the consequence of activation of an apoptotic pathway. Here we show that two proapoptotic drugs, dexamethasone and 2[[3-(2,3-dichlorophenoxy)propyl]amino]-ethanol, each accelerates viral gene expression in ganglionic organ cultures. We also show that in cultured cells apoptosis induced by dexamethasone accelerates viral gene expression and accumulation of infectious virus. The results are surprising in light of the relatively large number of viral proteins that independently block apoptosis induced by viral gene products or exogenous agents. The results suggest that the virus may rely on apoptosis to exit from latency but that apoptosis may be detrimental for virus replication or spread at the portal of entry into the body. PMID:22908263

  7. Bioactive Molecules Released From Cells Infected with the Human Cytomegalovirus

    PubMed Central

    Luganini, Anna; Terlizzi, Maria E.; Gribaudo, Giorgio

    2016-01-01

    Following primary infection in humans, the human cytomegalovirus (HCMV) persists in a latent state throughout the host’s lifetime despite a strong and efficient immune response. If the host experiences some form of immune dysregulation, such as immunosuppression or immunodeficiency, HCMV reactivates, thereby emerging from latency. Thus, in the absence of effective functional immune responses, as occurs in immunocompromised or immunoimmature individuals, both HCMV primary infections and reactivations from latency can cause significant morbidity and mortality. However, even in immunocompetent hosts, HCMV represents a relevant risk factor for the development of several chronic inflammatory diseases and certain forms of neoplasia. HCMV infection may shift between the lytic and latent state, regulated by a delicate and intricate balance between virus-mediated immunomodulation and host immune defenses. Indeed, HCMV is a master in manipulating innate and adaptive host defense pathways, and a large portion of its genome is devoted to encoding immunomodulatory proteins; such proteins may thus represent important virulence determinants. However, the pathogenesis of HCMV-related diseases is strengthened by the activities of bioactive molecules, of both viral and cellular origin, that are secreted from infected cells and collectively named as the secretome. Here, we review the state of knowledge on the composition and functions of HCMV-derived secretomes. In lytic infections of fibroblasts and different types of endothelial cells, the majority of HCMV-induced secreted proteins act in a paracrine fashion to stimulate the generation of an inflammatory microenvironment around infected cells; this may lead to vascular inflammation and angiogenesis that, in turn, foster HCMV replication and its dissemination through host tissues. Conversely, the HCMV secretome derived from latently infected hematopoietic progenitor cells induces an immunosuppressive extracellular environment that

  8. Bioactive Molecules Released From Cells Infected with the Human Cytomegalovirus.

    PubMed

    Luganini, Anna; Terlizzi, Maria E; Gribaudo, Giorgio

    2016-01-01

    Following primary infection in humans, the human cytomegalovirus (HCMV) persists in a latent state throughout the host's lifetime despite a strong and efficient immune response. If the host experiences some form of immune dysregulation, such as immunosuppression or immunodeficiency, HCMV reactivates, thereby emerging from latency. Thus, in the absence of effective functional immune responses, as occurs in immunocompromised or immunoimmature individuals, both HCMV primary infections and reactivations from latency can cause significant morbidity and mortality. However, even in immunocompetent hosts, HCMV represents a relevant risk factor for the development of several chronic inflammatory diseases and certain forms of neoplasia. HCMV infection may shift between the lytic and latent state, regulated by a delicate and intricate balance between virus-mediated immunomodulation and host immune defenses. Indeed, HCMV is a master in manipulating innate and adaptive host defense pathways, and a large portion of its genome is devoted to encoding immunomodulatory proteins; such proteins may thus represent important virulence determinants. However, the pathogenesis of HCMV-related diseases is strengthened by the activities of bioactive molecules, of both viral and cellular origin, that are secreted from infected cells and collectively named as the secretome. Here, we review the state of knowledge on the composition and functions of HCMV-derived secretomes. In lytic infections of fibroblasts and different types of endothelial cells, the majority of HCMV-induced secreted proteins act in a paracrine fashion to stimulate the generation of an inflammatory microenvironment around infected cells; this may lead to vascular inflammation and angiogenesis that, in turn, foster HCMV replication and its dissemination through host tissues. Conversely, the HCMV secretome derived from latently infected hematopoietic progenitor cells induces an immunosuppressive extracellular environment that

  9. Short Communication: The Broad-Spectrum Histone Deacetylase Inhibitors Vorinostat and Panobinostat Activate Latent HIV in CD4(+) T Cells In Part Through Phosphorylation of the T-Loop of the CDK9 Subunit of P-TEFb.

    PubMed

    Jamaluddin, Md Saha; Hu, Pei-Wen; Jan, Yih; Siwak, Edward B; Rice, Andrew P

    2016-02-01

    Cessation of highly active antiretroviral therapy (HAART) in HIV-infected individual leads to a rebound of viral replication due to reactivation of a viral reservoir composed largely of latently infected memory CD4(+) T cells. Efforts to deplete this reservoir have focused on reactivation of transcriptionally silent latent proviruses. HIV provirus transcription depends critically on the positive transcription elongation factor b (P-TEFb), whose core components are cyclin-dependent kinase 9 (CDK9) and cyclin T1. In resting CD4(+) cells, the functional levels of P-TEFb are extremely low. Cellular activation upregulates cyclin T1 protein levels and CDK9 T-loop (T186) phosphorylation. The broad-spectrum histone deacetylase inhibitors (HDACis) vorinostat and panobinostat have been shown to reactivate latent virus in vivo in HAART-treated individuals. In this study, we have found that vorinostat and panobinostat activate P-TEFb in resting primary CD4(+) T cells through induction of CDK9 T-loop phosphorylation. In contrast, tacedinaline and romidepsin, HDAC 1 and 2 inhibitors, were unable to activate CDK9 T-loop phosphorylation. We used a CCL19 primary CD4(+) T-cell model HIV latency to assess the correlation between induction of CDK9 T-loop phosphorylation and reactivation of latent HIV virus by HDACis. Vorinostat and panobinostat treatment of cells harboring latent HIV increased CDK9 T-loop phosphorylation and reactivation of latent virus, whereas tacedinaline and romidepsin failed to induce T-loop phosphorylation or reactivate latent virus. We conclude that the ability of vorinostat and panobinostat to induce latent HIV is, in part, likely due to the ability of the broad-spectrum HDACis to upregulate P-TEFb through increased CDK9 T-loop phosphorylation. PMID:26727990

  10. Lolium latent virus (Alphaflexiviridae) coat proteins: expression and functions in infected plant tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Lolium latent virus (LoLV, Lolavirus, Alphaflexiviridae) viral genome is encapsidated by two carboxy-coterminal coat protein (CP) variants (about 28 and 33 kDa), in equimolar proportion. The CP ORF contains two 5'-proximal AUGs, encoding Met 1 and Met 49, respectively promoting translation of th...

  11. Targeting the latent reservoir to achieve functional HIV cure

    PubMed Central

    Cary, Daniele C.; Peterlin, B. Matija

    2016-01-01

    While highly active anti-retroviral therapy has greatly improved the lives of HIV-infected individuals, current treatments are unable to completely eradicate the virus. This is due to the presence of HIV latently infected cells which harbor transcriptionally silent HIV. Latent HIV does not replicate or produce viral proteins, thereby preventing efficient targeting by anti-retroviral drugs. Strategies to target the HIV latent reservoir include viral reactivation, enhancing host defense mechanisms, keeping latent HIV silent, and using gene therapy techniques to knock out or reactivate latent HIV. While research into each of these areas has yielded promising results, currently no one mechanism eradicates latent HIV. Instead, combinations of these approaches should be considered for a potential HIV functional cure. PMID:27303638

  12. A passive-flow microfluidic device for imaging latent HIV activation dynamics in single T cells

    PubMed Central

    Gearhart, Larisa M.; Miller-Jensen, Kathryn

    2015-01-01

    Quantifying cell-to-cell variability in drug response dynamics is important when evaluating therapeutic efficacy. For example, optimizing latency reversing agents (LRAs) for use in a clinical “activate-and-kill” strategy to purge the latent HIV reservoir in patients requires minimizing heterogeneous viral activation dynamics. To evaluate how heterogeneity in latent HIV activation varies across a range of LRAs, we tracked drug-induced response dynamics in single cells via live-cell imaging using a latent HIV–GFP reporter virus in a clonal Jurkat T cell line. To enable these studies in suspension cells, we designed a simple method to capture an array of single Jurkat T cells using a passive-flow microfluidic device. Our device, which does not require external pumps or tubing, can trap hundreds of cells within minutes with a high retention rate over 12 hours of imaging. Using this device, we quantified heterogeneity in viral activation stimulated by transcription factor (TF) activators and histone deacetylase (HDAC) inhibitors. Generally, TF activators resulted in both faster onset of viral activation and faster rates of production, while HDAC inhibitors resulted in more uniform onset times, but more heterogeneous rates of production. Finally, we demonstrated that while onset time of viral gene expression and rate of viral production together predict total HIV activation, rate and onset time were not correlated within the same individual cell, suggesting that these features are regulated independently. Overall, our results reveal drug-specific patterns of noisy HIV activation dynamics not previously identified in static single-cell assays, which may require consideration for the most effective activate-and-kill regime. PMID:26138068

  13. A Herpesviral Lytic Protein Regulates the Structure of Latent Viral Chromatin

    PubMed Central

    Raja, Priya; Lee, Jennifer S.; Pan, Dongli; Pesola, Jean M.; Coen, Donald M.

    2016-01-01

    ABSTRACT Latent infections by viruses usually involve minimizing viral protein expression so that the host immune system cannot recognize the infected cell through the viral peptides presented on its cell surface. Herpes simplex virus (HSV), for example, is thought to express noncoding RNAs such as latency-associated transcripts (LATs) and microRNAs (miRNAs) as the only abundant viral gene products during latent infection. Here we describe analysis of HSV-1 mutant viruses, providing strong genetic evidence that HSV-infected cell protein 0 (ICP0) is expressed during establishment and/or maintenance of latent infection in murine sensory neurons in vivo. Studies of an ICP0 nonsense mutant virus showed that ICP0 promotes heterochromatin and latent and lytic transcription, arguing that ICP0 is expressed and functional. We propose that ICP0 promotes transcription of LATs during establishment or maintenance of HSV latent infection, much as it promotes lytic gene transcription. This report introduces the new concept that a lytic viral protein can be expressed during latent infection and can serve dual roles to regulate viral chromatin to optimize latent infection in addition to its role in epigenetic regulation during lytic infection. An additional implication of the results is that ICP0 might serve as a target for an antiviral therapeutic acting on lytic and latent infections. PMID:27190217

  14. Histone deacetylases and the nuclear receptor corepressor regulate lytic-latent switch gene 50 in murine gammaherpesvirus 68-infected macrophages.

    PubMed

    Goodwin, Megan M; Molleston, Jerome M; Canny, Susan; Abou El Hassan, Mohamed; Willert, Erin K; Bremner, Rod; Virgin, Herbert W

    2010-11-01

    Gammaherpesviruses are important oncogenic pathogens that transit between lytic and latent life cycles. Silencing the lytic gene expression program enables the establishment of latency and a lifelong chronic infection of the host. In murine gammaherpesvirus 68 (MHV68, γHV68), essential lytic switch gene 50 controls the interchange between lytic and latent gene expression programs. However, negative regulators of gene 50 expression remain largely undefined. We report that the MHV68 lytic cycle is silenced in infected macrophages but not fibroblasts and that histone deacetylases (HDACs) mediate silencing. The HDAC inhibitor trichostatin A (TSA) acts on the gene 50 promoter to induce lytic replication of MHV68. HDAC3, HDAC4, and the nuclear receptor corepressor (NCoR) are required for efficient silencing of gene 50 expression. NCoR is critical for transcriptional repression of cellular genes by unliganded nuclear receptors. Retinoic acid, a known ligand for the NCoR complex, derepresses gene 50 expression and enhances MHV68 lytic replication. Moreover, HDAC3, HDAC4, and NCoR act on the gene 50 promoter and are recruited to this promoter in a retinoic acid-responsive manner. We provide the first example of NCoR-mediated, HDAC-dependent regulation of viral gene expression. PMID:20719946

  15. Extracellular vesicles from infected cells: potential for direct pathogenesis

    PubMed Central

    Schwab, Angela; Meyering, Shabana S.; Lepene, Ben; Iordanskiy, Sergey; van Hoek, Monique L.; Hakami, Ramin M.; Kashanchi, Fatah

    2015-01-01

    Infections that result in natural or manmade spread of lethal biological agents are a concern and require national and focused preparedness. In this manuscript, as part of an early diagnostics and pathogen treatment strategy, we have focused on extracellular vesicles (EVs) that arise following infections. Although the field of biodefense does not currently have a rich resource in EVs literature, none the less, similar pathogens belonging to the more classical emerging and non-emerging diseases have been studied in their EV/exosomal contents and function. These exosomes are formed in late endosomes and released from the cell membrane in almost every cell type in vivo. These vesicles contain proteins, RNA, and lipids from the cells they originate from and function in development, signal transduction, cell survival, and transfer of infectious material. The current review focuses on how different forms of infection exploit the exosomal pathway and how exosomes can be exploited artificially to treat infection and disease and potentially also be used as a source of vaccine. Virally-infected cells can secrete viral as well as cellular proteins and RNA in exosomes, allowing viruses to cause latent infection and spread of miRNA to nearby cells prior to a subsequent infection. In addition to virally-infected host cells, bacteria, protozoa, and fungi can all release small vesicles that contain pathogen-associated molecular patterns, regulating the neighboring uninfected cells. Examples of exosomes from both virally and bacterially infected cells point toward a re-programming network of pathways in the recipient cells. Finally, many of these exosomes contain cytokines and miRNAs that in turn can effect gene expression in the recipient cells through the classical toll-like receptor and NFκB pathway. Therefore, although exosomes do not replicate as an independent entity, they however facilitate movement of infectious material through tissues and may be the cause of many

  16. Extracellular vesicles from infected cells: potential for direct pathogenesis.

    PubMed

    Schwab, Angela; Meyering, Shabana S; Lepene, Ben; Iordanskiy, Sergey; van Hoek, Monique L; Hakami, Ramin M; Kashanchi, Fatah

    2015-01-01

    Infections that result in natural or manmade spread of lethal biological agents are a concern and require national and focused preparedness. In this manuscript, as part of an early diagnostics and pathogen treatment strategy, we have focused on extracellular vesicles (EVs) that arise following infections. Although the field of biodefense does not currently have a rich resource in EVs literature, none the less, similar pathogens belonging to the more classical emerging and non-emerging diseases have been studied in their EV/exosomal contents and function. These exosomes are formed in late endosomes and released from the cell membrane in almost every cell type in vivo. These vesicles contain proteins, RNA, and lipids from the cells they originate from and function in development, signal transduction, cell survival, and transfer of infectious material. The current review focuses on how different forms of infection exploit the exosomal pathway and how exosomes can be exploited artificially to treat infection and disease and potentially also be used as a source of vaccine. Virally-infected cells can secrete viral as well as cellular proteins and RNA in exosomes, allowing viruses to cause latent infection and spread of miRNA to nearby cells prior to a subsequent infection. In addition to virally-infected host cells, bacteria, protozoa, and fungi can all release small vesicles that contain pathogen-associated molecular patterns, regulating the neighboring uninfected cells. Examples of exosomes from both virally and bacterially infected cells point toward a re-programming network of pathways in the recipient cells. Finally, many of these exosomes contain cytokines and miRNAs that in turn can effect gene expression in the recipient cells through the classical toll-like receptor and NFκB pathway. Therefore, although exosomes do not replicate as an independent entity, they however facilitate movement of infectious material through tissues and may be the cause of many

  17. The Ozobranchus leech as a mechanical vector for the fibropapilloma-associated turtle herpes virus found latently infecting skin tumors on Hawaiian green turtles (Chelonia mydas)

    USGS Publications Warehouse

    Greenblatt, R.J.; Work, T.M.; Balazs, G.; Sutton, C.A.; Casey, R.N.; Casey, J.W.

    2004-01-01

    Fibropapillomatosis (FP) of marine turtles is a neoplastic disease of ecological concern. A fibropapilloma-associated turtle herpesvirus (FPTHV) is consistently present, usually at loads exceeding one virus copy per tumor cell. DNA from an array of parasites of green turtles (Chelonia mydas) was examined with quantitative PCR (qPCR) to determine whether any carried viral loads are sufficient to implicate them as vectors for FPTHV. Marine leeches (Ozobranchus spp.) were found to carry high viral DNA loads; some samples approached 10 million copies per leech. Isopycnic sucrose density gradient/qPCR analysis confirmed that some of these copies were associated with particles of the density of enveloped viruses. The data implicate the marine leech Ozobranchus as a mechanical vector for FPTHV. Quantitative RT-PCR analysis of FPTHV gene expression indicated that most of the FPTHV copies in a fibropapilloma have restricted DNA polymerase expression, suggestive of latent infection.

  18. Prevalence of Latent and Active Tuberculosis among Dairy Farm Workers Exposed to Cattle Infected by Mycobacterium bovis

    PubMed Central

    Torres-Gonzalez, Pedro; Soberanis-Ramos, Orbelin; Martinez-Gamboa, Areli; Chavez-Mazari, Barbara; Barrios-Herrera, Ma Teresa; Torres-Rojas, Martha; Cruz-Hervert, Luis Pablo; Garcia-Garcia, Lourdes; Singh, Mahavir; Gonzalez-Aguirre, Adrian; Ponce de Leon-Garduño, Alfredo; Sifuentes-Osornio, José; Bobadilla-del-Valle, Miriam

    2013-01-01

    Background Human tuberculosis caused by M. bovis is a zoonosis presently considered sporadic in developed countries, but remains a poorly studied problem in low and middle resource countries. The disease in humans is mainly attributed to unpasteurized dairy products consumption. However, transmission due to exposure of humans to infected animals has been also recognized. The prevalence of tuberculosis infection and associated risk factors have been insufficiently characterized among dairy farm workers (DFW) exposed in settings with poor control of bovine tuberculosis. Methodology/Principal Findings Tuberculin skin test (TST) and Interferon-gamma release assay (IGRA) were administered to 311 dairy farm and abattoir workers and their household contacts linked to a dairy production and livestock facility in Mexico. Sputa of individuals with respiratory symptoms and samples from routine cattle necropsies were cultured for M. bovis and resulting spoligotypes were compared. The overall prevalence of latent tuberculosis infection (LTBI) was 76.2% (95% CI, 71.4–80.9%) by TST and 58.5% (95% CI, 53.0–64.0%) by IGRA. Occupational exposure was associated to TST (OR 2.72; 95% CI, 1.31–5.64) and IGRA (OR 2.38; 95% CI, 1.31–4.30) adjusting for relevant variables. Two subjects were diagnosed with pulmonary tuberculosis, both caused by M. bovis. In one case, the spoligotype was identical to a strain isolated from bovines. Conclusions We documented a high prevalence of latent and pulmonary TB among workers exposed to cattle infected with M. bovis, and increased risk among those occupationally exposed in non-ventilated spaces. Interspecies transmission is frequent and represents an occupational hazard in this setting. PMID:23638198

  19. Chromatin organization of gammaherpesvirus latent genomes.

    PubMed

    Tempera, Italo; Lieberman, Paul M

    2010-01-01

    The gammaherpesviruses are a subclass of the herpesvirus family that establish stable latent infections in proliferating lymphoid and epithelial cells. The latent genomes are maintained as multicopy chromatinized episomes that replicate in synchrony with the cellular genome. Importantly, most of the episomes do not integrate into the host chromosome. Therefore, it is essential that the viral "minichromosome" establish a chromatin structure that is suitable for gene expression, DNA replication, and chromosome segregation. Evidence suggests that chromatin organization is important for each of these functions and plays a regulatory role in the establishment and maintenance of latent infection. Here, we review recent studies on the chromatin organization of the human gammaherpesviruses, Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV). We discuss the potential role of viral origins of DNA replication and viral encoded origin-binding proteins like EBNA1 and LANA in establishment of viral chromosome organization during latent infection. We also discuss the roles of host cell factors, like CTCF and cohesins, that contribute to higher-order chromosome structures that may be important for stable gene expression programs during latent infection in proliferating cells. PMID:19853673

  20. Identification and Sequencing of a Novel Rodent Gammaherpesvirus That Establishes Acute and Latent Infection in Laboratory Mice ▿

    PubMed Central

    Loh, Joy; Zhao, Guoyan; Nelson, Christopher A.; Coder, Penny; Droit, Lindsay; Handley, Scott A.; Johnson, L. Steven; Vachharajani, Punit; Guzman, Hilda; Tesh, Robert B.; Wang, David; Fremont, Daved H.; Virgin, Herbert W.

    2011-01-01

    Gammaherpesviruses encode numerous immunomodulatory molecules that contribute to their ability to evade the host immune response and establish persistent, lifelong infections. As the human gammaherpesviruses are strictly species specific, small animal models of gammaherpesvirus infection, such as murine gammaherpesvirus 68 (γHV68) infection, are important for studying the roles of gammaherpesvirus immune evasion genes in in vivo infection and pathogenesis. We report here the genome sequence and characterization of a novel rodent gammaherpesvirus, designated rodent herpesvirus Peru (RHVP), that shares conserved genes and genome organization with γHV68 and the primate gammaherpesviruses but is phylogenetically distinct from γHV68. RHVP establishes acute and latent infection in laboratory mice. Additionally, RHVP contains multiple open reading frames (ORFs) not present in γHV68 that have sequence similarity to primate gammaherpesvirus immunomodulatory genes or cellular genes. These include ORFs with similarity to major histocompatibility complex class I (MHC-I), C-type lectins, and the mouse mammary tumor virus and herpesvirus saimiri superantigens. As these ORFs may function as immunomodulatory or virulence factors, RHVP presents new opportunities for the study of mechanisms of immune evasion by gammaherpesviruses. PMID:21209105

  1. Experimental infections of rabbits with proliferative and latent stages of Besnoitia besnoiti.

    PubMed

    Liénard, Emmanuel; Pop, Loredana; Prevot, Françoise; Grisez, Christelle; Mallet, Virginie; Raymond-Letron, Isabelle; Bouhsira, Émilie; Franc, Michel; Jacquiet, Philippe

    2015-10-01

    Cattle besnoitiosis due to Besnoitia besnoiti is spreading across Europe and is responsible for severe economic losses in newly infected herds. Experimentally speaking, rabbits have been found to be susceptible to this parasite. The adaptation of B. besnoiti to rabbits may offer a new, easier and cheaper model of investigation for this disease. This study compared the virulence between tachyzoites and bradyzoites of B. besnoiti in rabbits. Eighteen New Zealand rabbits were allocated into three groups of six animals each. The rabbits from the control (group C), "tachyzoite" (group T) and "bradyzoite" (group B) groups were subcutaneously injected in the right flank with 66 μg of ovalbumin, 6.10(6) tachyzoites (125th passage on Vero cells) and 6.10(6) bradyzoites (collected from a natural infected cow) of B. besnoiti, respectively. Clinical follow-up and blood sampling for serological survey and qPCR were performed during 10 weeks until euthanasia. Molecular and immunohistochemistry examination was achieved on 25 samples of tissue per rabbit. Seroconversion occurred in group T without any clinical signs. Rabbits of group B exhibited a febrile condition (temperature above 40 °C from day 8 to day 11 following injection) with positive qPCR in blood. Cysts of B. besnoiti were found on skin samples and organs of rabbits from group B in tissue explored with threshold cycle (Ct) values below 30. These results suggest a higher virulence of bradyzoites in rabbits than Vero cell-cultivated tachyzoites. The proposed model could be used to assess the in vivo effectiveness of vaccine or drugs against cattle besnoitiosis. PMID:26143866

  2. The Prevalence of Latent Tuberculosis Infection and Smear Positive Pulmonary Tuberculosis in People with Household Close Contact with Tuberculosis in North of Iran

    PubMed Central

    Moosazadeh, Mahmood; Khanjani, Narges; Parsaee, Mohammadreza

    2015-01-01

    One of the recommended strategies for preventing tuberculosis is to screen high-risk populations with respect to Mycobacterium tuberculosis (TB) infection. The aim of the present study was to investigate latent infection and active tuberculosis in people with close household contact. It was a cross-sectional descriptive, analytical study with the sample size of 668 people from homes with one infected resident. In order to diagnose tuberculosis latent infection, the PPD test was done. To determine patients with smear-positive pulmonary tuberculosis, three sputum samples were taken from every patient and were examined using direct microscopy and culture. Data was analyzed by SPSS20 software. The prevalence of latent tuberculosis infection and smear-positive pulmonary tuberculosis were 42.8% and 0.9% respectively. The prevalence of latent tuberculosis infection and smear-positive pulmonary tuberculosis in people with close household contact were less than that of other studies. However, smear-positive pulmonary tuberculosis in people with close household contact was 199.5 times more than that of the general population. PMID:25821296

  3. Quantifying the Turnover of Transcriptional Subclasses of HIV-1-Infected Cells

    PubMed Central

    Althaus, Christian L.; Joos, Beda; Perelson, Alan S.; Günthard, Huldrych F.

    2014-01-01

    HIV-1-infected cells in peripheral blood can be grouped into different transcriptional subclasses. Quantifying the turnover of these cellular subclasses can provide important insights into the viral life cycle and the generation and maintenance of latently infected cells. We used previously published data from five patients chronically infected with HIV-1 that initiated combination antiretroviral therapy (cART). Patient-matched PCR for unspliced and multiply spliced viral RNAs combined with limiting dilution analysis provided measurements of transcriptional profiles at the single cell level. Furthermore, measurement of intracellular transcripts and extracellular virion-enclosed HIV-1 RNA allowed us to distinguish productive from non-productive cells. We developed a mathematical model describing the dynamics of plasma virus and the transcriptional subclasses of HIV-1-infected cells. Fitting the model to the data allowed us to better understand the phenotype of different transcriptional subclasses and their contribution to the overall turnover of HIV-1 before and during cART. The average number of virus-producing cells in peripheral blood is small during chronic infection. We find that a substantial fraction of cells can become defectively infected. Assuming that the infection is homogenous throughout the body, we estimate an average in vivo viral burst size on the order of 104 virions per cell. Our study provides novel quantitative insights into the turnover and development of different subclasses of HIV-1-infected cells, and indicates that cells containing solely unspliced viral RNA are a good marker for viral latency. The model illustrates how the pool of latently infected cells becomes rapidly established during the first months of acute infection and continues to increase slowly during the first years of chronic infection. Having a detailed understanding of this process will be useful for the evaluation of viral eradication strategies that aim to deplete the

  4. Genes expressed in grapevine leaves reveal latent wood infection by the fungal pathogen Neofusicoccum parvum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Detection of wood-infecting pathogens is often limited to the late stage of infection, when disease symptoms are obvious. Detection of the early stage of infection would benefit from identification of host-based markers in asymptomatic leaves. The fungus Neofusicoccum parvum (Botryosphaeria diebac...

  5. Comparison of human sera reactivities in immunoblots with recombinant human herpesvirus (HHV)-8 proteins associated with the latent (ORF73) and lytic (ORFs 65, K8.1A, and K8.1B) replicative cycles and in immunofluorescence assays with HHV-8-infected BCBL-1 cells.

    PubMed

    Zhu, L; Wang, R; Sweat, A; Goldstein, E; Horvat, R; Chandran, B

    1999-04-10

    The development of reliable, sensitive, and specific serological methods for the detection of human herpesvirus-8 (HHV-8) antibodies is critical for a thorough understanding of HHV-8 prevalence and pathogenesis. To evaluate the potential usefulness of HHV-8 proteins in measuring the responses against both latent and lytic antigens, we selected 1 latent [open reading frame (ORF) 73] antigen and 3 HHV-8 lytic antigens (ORFs 65, K8.1A, and K8.1B) previously identified as immunogenic [Virology (1998) 243, 208-217]. Full-length genomic ORF 73 and full-length ORFs 65, K8.1A, and K8.1B from the cDNA clones were cloned, expressed in bacterial and baculovirus-insect cell expression systems, and purified as GST fusion proteins. These recombinant proteins were used in Western blot reactions to test sera from 104 human immunodeficiency virus (HIV)+/Kaposi's sarcoma (KS)+ homosexual men, 77 HIV+/KS- homosexual men, and 84 age-matched HIV-/KS- men. These sera were also tested in immunofluorescence assays (IFAs) with uninduced and 12-O-tetradecanoylphorbol-13-acetate-induced B cell lymphoma-1 cells to detect antibodies against latency-associated nuclear antigens (LANA) and antibodies against lytic antigens (cytoplasmic fluorescence). These sera exhibited differential reactivities reflecting different titers of antibodies against HHV-8 proteins, and variable reactivities were seen more commonly with the sera from HIV-/KS- adult men. In the Western blot assay, 89% (93 of 104) of HIV+/KS + sera, 60% (46 of 77) of HIV+/KS- sera, and 7% (6 of 84) HIV+/KS- sera were reactive with both latent and lytic recombinant antigens. Western blot reactions with ORF 73 protein were more sensitive than LANA-IFA results. The lytic IFA and lytic Western blot (ORFs 65 and K8.1A) assays were more sensitive than the ORF 73 Western blots and LANA-IFA. With an exception of 2 sera from the HIV-/KS- group, all sera positive for lytic IFA antibodies and ORF 65 and K8.1A antibodies were also positive for

  6. Progress toward curing HIV infections with hematopoietic stem cell transplantation.

    PubMed

    Smiley, Stephen T; Singh, Anjali; Read, Sarah W; Sharma, Opendra K; Finzi, Diana; Lane, Clifford; Rice, Jeffrey S

    2015-01-15

    Combination antiretroviral therapy can suppress human immunodeficiency virus (HIV) infection but cannot completely eradicate the virus. A major obstacle in the quest for a cure is the difficulty in targeting and measuring latently infected cells. To date, a single person seems to have been cured of HIV. Hematopoietic stem cell transplantation (HSCT) preceded this cancer patient's long-term sustained HIV remission, but researchers have been unable to replicate this cure, and the mechanisms that led to HIV remission remain to be established. In February 2014, the National Institute of Allergy and Infectious Diseases sponsored a workshop that provided a venue for in-depth discussion of whether HSCT could be exploited to cure HIV in cancer patients requiring such procedures. Participants also discussed how HSCT might be applied to a broader community of HIV-infected persons in whom the risks of HSCT currently outweigh the likelihood and benefits of HIV cure. PMID:25273081

  7. Targeted screening and treatment for latent tuberculosis infection using QuantiFERON®-TB Gold is cost-effective in Mexico

    PubMed Central

    Burgos, J. L.; Kahn, J. G.; Strathdee, S. A.; Valencia-Mendoza, A.; Bautista-Arredondo, S.; Laniado-Laborin, R.; Castañeda, R.; Deiss, R.; Garfein, R. S.

    2009-01-01

    SUMMARY OBJECTIVE To assess the cost-effectiveness of screening for latent tuberculosis infection (LTBI) using a commercially available detection test and treating individuals at high risk for human immunodeficiency virus (HIV) infection in a middle-income country. DESIGN We developed a Markov model to evaluate the cost per LTBI case detected, TB case averted and quality-adjusted life year (QALY) gained for a cohort of 1000 individuals at high risk for HIV infection over 20 years. Baseline model inputs for LTBI prevalence were obtained from published literature and cross-sectional data from tuberculosis (TB) screening using QuantiFERON®-TB Gold In-Tube (QFT-GIT) testing among sex workers and illicit drug users at high risk for HIV recruited through street outreach in Tijuana, Mexico. Costs are reported in 2007 US dollars. Future costs and QALYs were discounted at 3% per year. Sensitivity analyses were performed to evaluate model robustness. RESULTS Over 20 years, we estimate the program would prevent 78 cases of active TB and 55 TB-related deaths. The incremental cost per case of LTBI detected was US$730, cost per active TB averted was US$529 and cost per QALY gained was US$108. CONCLUSIONS In settings of endemic TB and escalating HIV incidence, targeting LTBI screening and treatment among high-risk groups may be highly cost-effective. PMID:19723375

  8. The herpes simplex virus type 1 immediate-early protein ICP0 is necessary for the efficient establishment of latent infection.

    PubMed

    Wilcox, C L; Smith, R L; Everett, R D; Mysofski, D

    1997-09-01

    The immediate-early protein ICP0 of herpes simplex virus type 1 (HSV-1) is not essential for viral replication. However, ICP0 is important for efficient viral replication during the productive infection and for reactivation of latent HSV-1 in vivo. The in vitro model of HSV-1 latency in dorsal root ganglia neurons was used to examine the role of ICP0 in the individual steps that could lead to the appearance of a decreased reactivation phenotype of ICP0 mutant viruses. After establishment of latent infections in the neuronal cultures, induction of reactivation by nerve growth factor (NGF) deprivation resulted in the production of infectious virus with delayed kinetics and a burst size that was significantly decreased for the ICP0 mutants compared with wild-type HSV-1. The efficiency of establishment of latency with the ICP0 mutants was similarly decreased at least 10-fold, as measured by three criteria: (i) the percentage of neurons expressing the major latency-associated transcript during the latent infection, (ii) the amount of viral DNA detected in the neuronal cultures, and (iii) the percentage of neurons expressing ICP4 immunoreactivity after the induction of reactivation. The most striking finding was that ICP0 supplied by an adenovirus vector significantly restored the ability of an ICP0 mutant to establish latency and reactivation. These results strongly indicate a critical role for ICP0 in the establishment of the latent HSV-1 infection in the in vitro neuronal model. PMID:9261402

  9. Localization of Herpes Simplex Virus Type 1 DNA in Latently Infected BALB/c Mice Neurons Using in situ Polymerase Chain Reaction

    PubMed Central

    Khansarinejad, Behzad; Soleimanjahi, Hoorieh; Ghaemi, Amir; Tiraihi, Taki; Pour Beiranvand, Shahram

    2010-01-01

    Background: Herpes simplex virus type-1 (HSV-1) establishes a lifelong latent infection in neurons following primary infection. The existence of latent HSV-1 DNA in the trigeminal ganglia of infected BALB/c mice was examined using a direct in situ PCR technique, based on Digoxigenin-11-dUTP detection system with anti-digoxigenin-peroxidase and 3,3'-diaminobenzidine (DAB) substrate. Methods: Eight-week-old male BALB/c mice were inoculated via the eye by 104 plaque forming unit of wild type Iranian isolates of HSV-1. After establishment of latency, trigeminal ganglia were removed and examined using in situ PCR to detect HSV-1 genome. Finally, the results of in situ PCR were verified by a two-round PCR method, using amplification cocktail of in situ reaction, as a template for a conventional gel base PCR. Results and Conclusion: The results suggest that a direct in situ PCR method using a peroxidase and DAB detection system is a useful means for detection of latent HSV-1 DNA in the latently infected ganglia. PMID:21079658

  10. Completion Rate and Side-Effect Profile of Three-Month Isoniazid and Rifapentine Treatment for Latent Tuberculosis Infection in an Urban County Jail

    PubMed Central

    Juarez-Reyes, Maria; Gallivan, Mark; Chyorny, Alexander; O'Keeffe, Linda; Shah, Neha S.

    2016-01-01

    In an urban jail population, 3 months of isoniazid and rifapentine (3HP) was associated with an 85% latent tuberculosis infection treatment completion rate compared with 18% in a standard 9-month isoniazid treatment group. Among the 91 patients who started 3HP therapy, there were 2 treatment discontinuations from adverse drug reactions. PMID:26885547

  11. ß-catenin, a transcription factor activated by canonical Wnt signaling, is expressed in sensory neurons of calves latently infected with bovine herpesvirus 1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Like many a-herpesvirinae subfamily members, bovine herpes virus 1 (BoHV-1) expresses an abundant transcript in latently infected sensory neurons: the latency-related (LR) RNA. LR-RNA encodes a protein (ORF2) that inhibits apoptosis, interacts with Notch family members, interferes with Notch mediate...

  12. Attenuation of Toll-Like Receptor Expression and Function in Latent Tuberculosis by Coexistent Filarial Infection with Restoration Following Antifilarial Chemotherapy

    PubMed Central

    Babu, Subash; Bhat, Sajid Q.; Kumar, N. Pavan; Anuradha, R.; Kumaran, Paul; Gopi, P. G.; Kolappan, C.; Kumaraswami, V.; Nutman, Thomas B.

    2009-01-01

    Mycobacterium tuberculosis (Mtb) and filarial coinfection is highly prevalent, and the presence of filarial infections may regulate the Toll-like receptor (TLR)-dependent immune response needed to control Mtb infection. By analyzing the baseline and mycobacterial antigen–stimulated expression of TLR1, 2, 4, and 9 (in individuals with latent tuberculosis [TB] with or without filarial infection), we were able to demonstrate that filarial infection, coincident with Mtb, significantly diminishes both baseline and Mtb antigen-specific TLR2 and TLR9 expression. In addition, pro-inflammatory cytokine responses to TLR2 and 9 ligands are significantly diminished in filaria/TB-coinfected individuals. Definitive treatment of lymphatic filariasis significantly restores the pro-inflammatory cytokine responses in individuals with latent TB. Coincident filarial infection exerted a profound inhibitory effect on protective mycobacteria-specific TLR-mediated immune responses in latent tuberculosis and suggests a novel mechanism by which concomitant filarial infections predispose to the development of active tuberculosis in humans. PMID:19636364

  13. Estimation of test characteristics of real-time PCR and bacterial culture for diagnosis of subclinical intramammary infections with Streptococcus agalactiae in Danish dairy cattle in 2012 using latent class analysis.

    PubMed

    Mahmmod, Yasser S; Toft, Nils; Katholm, Jørgen; Grønbæk, Carsten; Klaas, Ilka C

    2013-05-01

    The misdiagnosis of intramammary infections (IMI) with Streptococcus agalactiae (S. agalactiae) could lead farmers to treat or cull animals unnecessarily. The objective of this field study was to estimate the sensitivity (Se) and specificity (Sp) of real-time PCR at different cut-offs for cycle threshold (Ct) values against bacterial culture (BC) for diagnosis of S. agalactiae IMI using latent class analysis to avoid the assumption of a perfect reference test. A total of 614 dairy cows were randomly selected from 6 herds with bulk tank PCR Ct value ≤ 39 for S. agalactiae and S. aureus. At milk recording, 2456 quarter milk samples were taken aseptically for BC and the routinely taken cow level milk samples were analyzed by PCR. Results showed that 53 cows (8.6%) were positive for S. agalactiae IMI by BC. Sensitivity of PCR at cut-offs; ≤ 39, ≤ 37, ≤ 34, and ≤ 32, was 96.2%, 91.9%, 87.2% and 73.9%, while Se of BC was 25.7%, 29.9%, 59.9% and 72.1%. Specificity of PCR at cut-offs; ≤ 39, ≤ 37, ≤ 34, and ≤ 32, was 96.8%, 96.9%, 96.7%, and 97.22%, while Sp of BC was 99.7%, 99.5%, 99.2%, and 98.9%. The estimated prevalence of S. agalactiae IMI by PCR was higher than the apparent prevalence at the tested cut-offs, indicating under estimation of S. agalactiae IMI in the examined dairy cows. In conclusion, Se of PCR is always higher than Se of BC at all tested cut-offs. The lower cut-off, the more comparable becomes Se of PCR and Se of BC. The changes in Se in both PCR and BC at different Ct-value cut-offs may indicate a change in the definition of the latent infection. The similar Se of both tests at cut-off ≤ 32 may indicate high concentrations of S. agalactiae viable cells, representing a cow truly/heavily infected with S. agalactiae and thus easier to detect with BC. At cut-off ≤ 39 the latent definition of infection may reflect a more general condition of cows being positive for S. agalactiae. Our findings indicate that PCR Ct-value cut-offs should

  14. Systematic Expression Profiling Analysis Identifies Specific MicroRNA-Gene Interactions that May Differentiate between Active and Latent Tuberculosis Infection

    PubMed Central

    Wu, Lawrence Shih-Hsin; Huang, Kai-Yao; Lee, Tzong-Yi; Hsu, Paul Wei-Che

    2014-01-01

    Tuberculosis (TB) is the second most common cause of death from infectious diseases. About 90% of those infected are asymptomatic—the so-called latent TB infections (LTBI), with a 10% lifetime chance of progressing to active TB. To further understand the molecular pathogenesis of TB, several molecular studies have attempted to compare the expression profiles between healthy controls and active TB or LTBI patients. However, the results vary due to diverse genetic backgrounds and study designs and the inherent complexity of the disease process. Thus, developing a sensitive and efficient method for the detection of LTBI is both crucial and challenging. For the present study, we performed a systematic analysis of the gene and microRNA profiles of healthy individuals versus those affected with TB or LTBI. Combined with a series of in silico analysis utilizing publicly available microRNA knowledge bases and published literature data, we have uncovered several microRNA-gene interactions that specifically target both the blood and lungs. Some of these molecular interactions are novel and may serve as potential biomarkers of TB and LTBI, facilitating the development for a more sensitive, efficient, and cost-effective diagnostic assay for TB and LTBI for the Taiwanese population. PMID:25276827

  15. 'Tipping the Balance': Karl Friedrich Meyer, Latent Infections, and the Birth of Modern Ideas of Disease Ecology.

    PubMed

    Honigsbaum, Mark

    2016-04-01

    The Swiss-born medical researcher Karl Friedrich Meyer (1884-1974) is best known as a 'microbe hunter' who pioneered investigations into diseases at the intersection of animal and human health in California in the 1920s and 1930s. In particular, historians have singled out Meyer's 1931 Ludwig Hektoen Lecture in which he described the animal kingdom as a 'reservoir of disease' as a forerunner of 'one medicine' approaches to emerging zoonoses. In so doing, however, historians risk overlooking Meyer's other intellectual contributions. Developed in a series of papers from the mid-1930s onwards, these were ordered around the concept of latent infections and sought to link microbial behavior to broader bio-ecological, environmental, and social factors that impact hostpathogen interactions. In this respect Meyer-like the comparative pathologist Theobald Smith and the immunologist Frank Macfarlane Burnet-can be seen as a pioneer of modern ideas of disease ecology. However, while Burnet's and Smith's contributions to this scientific field have been widely acknowledged, Meyer's have been largely ignored. Drawing on Meyer's published writings and private correspondence, this paper aims to correct that lacuna while contributing to a reorientation of the historiography of bacteriological epidemiology. In particular I trace Meyer's intellectual exchanges with Smith, Burnet and the animal ecologist Charles Elton, over brucellosis, psittacosis and plague-exchanges that not only showed how environmental and ecological conditions could 'tip the balance' in favor of parasites but which transformed Meyer thinking about resistance to infection and disease. PMID:26612760

  16. Human tissue mast cells are an inducible reservoir of persistent HIV infection.

    PubMed

    Sundstrom, J Bruce; Ellis, Jane E; Hair, Gregory A; Kirshenbaum, Arnold S; Metcalfe, Dean D; Yi, Hong; Cardona, Adriana C; Lindsay, Michael K; Ansari, Aftab A

    2007-06-15

    We have proposed that, unlike other HIV-vulnerable cell lineages, progenitor mast cells (prMCs), cultured in vitro from undifferentiated bone marrow-derived CD34(+) pluripotent progenitors (PPPs), are susceptible to infection during a limited period of their ontogeny. As infected prMCs mature in culture, they lose expression of viral chemokine coreceptors necessary for viral entry and develop into long-lived, latently infected mature tissue mast cells (MCs), resistant to new infection. In vivo recruitment of prMCs to different tissue compartments occurs in response to tissue injury, growth, and remodeling or allergic inflammation, allowing populations of circulating and potentially HIV-susceptible prMCs to spread persistent infection to diverse tissue compartments. In this report, we provide in vivo evidence to confirm this model by demonstrating that HIV-infected women have both circulating prMCs and placental tissue MCs (PLMCs) that harbor inducible infectious HIV even after highly active antiretroviral therapy (HAART) during pregnancy. Furthermore, infectious virus, capable of infecting alloactivated fetal cord blood mononuclear cells (CBMCs), could be induced in isolated latently infected PLMCs after weeks in culture in vitro. These data provide the first in vivo evidence that tissue MCs, developed from infected circulating prMCs, comprise a long-lived inducible reservoir of persistent HIV in infected persons during HAART. PMID:17351109

  17. Human tissue mast cells are an inducible reservoir of persistent HIV infection

    PubMed Central

    Ellis, Jane E.; Hair, Gregory A.; Kirshenbaum, Arnold S.; Metcalfe, Dean D.; Yi, Hong; Cardona, Adriana C.; Lindsay, Michael K.; Ansari, Aftab A.

    2007-01-01

    We have proposed that, unlike other HIV-vulnerable cell lineages, progenitor mast cells (prMCs), cultured in vitro from undifferentiated bone marrow–derived CD34+ pluripotent progenitors (PPPs), are susceptible to infection during a limited period of their ontogeny. As infected prMCs mature in culture, they lose expression of viral chemokine coreceptors necessary for viral entry and develop into long-lived, latently infected mature tissue mast cells (MCs), resistant to new infection. In vivo recruitment of prMCs to different tissue compartments occurs in response to tissue injury, growth, and remodeling or allergic inflammation, allowing populations of circulating and potentially HIV-susceptible prMCs to spread persistent infection to diverse tissue compartments. In this report, we provide in vivo evidence to confirm this model by demonstrating that HIV-infected women have both circulating prMCs and placental tissue MCs (PLMCs) that harbor inducible infectious HIV even after highly active antiretroviral therapy (HAART) during pregnancy. Furthermore, infectious virus, capable of infecting alloactivated fetal cord blood mononuclear cells (CBMCs), could be induced in isolated latently infected PLMCs after weeks in culture in vitro. These data provide the first in vivo evidence that tissue MCs, developed from infected circulating prMCs, comprise a long-lived inducible reservoir of persistent HIV in infected persons during HAART. PMID:17351109

  18. Interleukin-2 from Adaptive T Cells Enhances Natural Killer Cell Activity against Human Cytomegalovirus-Infected Macrophages

    PubMed Central

    Wu, Zeguang; Frascaroli, Giada; Bayer, Carina; Schmal, Tatjana

    2015-01-01

    ABSTRACT Control of human cytomegalovirus (HCMV) requires a continuous immune surveillance, thus HCMV is the most important viral pathogen in severely immunocompromised individuals. Both innate and adaptive immunity contribute to the control of HCMV. Here, we report that peripheral blood natural killer cells (PBNKs) from HCMV-seropositive donors showed an enhanced activity toward HCMV-infected autologous macrophages. However, this enhanced response was abolished when purified NK cells were applied as effectors. We demonstrate that this enhanced PBNK activity was dependent on the interleukin-2 (IL-2) secretion of CD4+ T cells when reexposed to the virus. Purified T cells enhanced the activity of purified NK cells in response to HCMV-infected macrophages. This effect could be suppressed by IL-2 blocking. Our findings not only extend the knowledge on the immune surveillance in HCMV—namely, that NK cell-mediated innate immunity can be enhanced by a preexisting T cell antiviral immunity—but also indicate a potential clinical implication for patients at risk for severe HCMV manifestations due to immunosuppressive drugs, which mainly suppress IL-2 production and T cell responsiveness. IMPORTANCE Human cytomegalovirus (HCMV) is never cleared by the host after primary infection but instead establishes a lifelong latent infection with possible reactivations when the host′s immunity becomes suppressed. Both innate immunity and adaptive immunity are important for the control of viral infections. Natural killer (NK) cells are main innate effectors providing a rapid response to virus-infected cells. Virus-specific T cells are the main adaptive effectors that are critical for the control of the latent infection and limitation of reinfection. In this study, we found that IL-2 secreted by adaptive CD4+ T cells after reexposure to HCMV enhances the activity of NK cells in response to HCMV-infected target cells. This is the first direct evidence that the adaptive T cells can

  19. Prevalence and correlates of latent tuberculosis infection among employees of a high security prison in Malaysia

    PubMed Central

    Al-Darraji, Haider Abdulrazzaq Abed; Tan, Cynthia; Kamarulzaman, Adeeba; Altice, Frederick L

    2015-01-01

    Objectives Although prison employees share the same tuberculosis (TB) risk environment with prisoners, the magnitude of TB problems among prison employees is unknown in most resource-limited prisons. This survey was conducted to investigate the prevalence and correlates of tuberculin skin test (TST) positivity among employees in Malaysia’s largest prison. Methods Consented, full-time prison employees were interviewed using a structured questionnaire that included sociodemographic data, history of working in the correctional system and TB-related risk. TST was placed intradermally and read after 48–72 h. Induration size of ≥10 mm was considered positive. Logistic regression analyses were conducted to explore associations with TST positivity. Results Of the 445 recruited prison employees, 420 (94.4%) had complete data. Most were young (median=30.0 years) men (88.8%) who had only worked at this prison (76.4%) for a median total employment period of 60 months (IQR 34.5–132.0). The majority were correctional officers, while civilian employees represented only 7.6% of the sample. Only 26 (6.2%) reported having ever been screened for TB since employment. Prevalence of TST positivity was 81% and was independently associated with longer (≥12 months) prison employment (AOR 4.9; 95% CI 1.5 to 15.9) and current tobacco smoking (AOR=1.9, 95% CI 1.2 to 3.2). Conclusions Latent TB prevalence was high in this sample, approximating that of prisoners in this setting, perhaps suggesting within prison TB transmission in this facility. Formal TB control programmes for personnel and prisoners alike are urgently needed within the Malaysian correctional system. PMID:25794506

  20. The Latent Reservoir for HIV-1: How Immunologic Memory and Clonal Expansion Contribute to HIV-1 Persistence.

    PubMed

    Murray, Alexandra J; Kwon, Kyungyoon J; Farber, Donna L; Siliciano, Robert F

    2016-07-15

    Combination antiretroviral therapy (ART) for HIV-1 infection reduces plasma virus levels to below the limit of detection of clinical assays. However, even with prolonged suppression of viral replication with ART, viremia rebounds rapidly after treatment interruption. Thus, ART is not curative. The principal barrier to cure is a remarkably stable reservoir of latent HIV-1 in resting memory CD4(+) T cells. In this review, we consider explanations for the remarkable stability of the latent reservoir. Stability does not appear to reflect replenishment from new infection events but rather normal physiologic processes that provide for immunologic memory. Of particular importance are proliferative processes that drive clonal expansion of infected cells. Recent evidence suggests that in some infected cells, proliferation is a consequence of proviral integration into host genes associated with cell growth. Efforts to cure HIV-1 infection by targeting the latent reservoir may need to consider the potential of latently infected cells to proliferate. PMID:27382129

  1. Aggressive Peripheral CD70-positive T-cell Lymphoma Associated with Severe Chronic Active EBV Infection

    PubMed Central

    Shaffer, Donald R.; Sheehan, Andrea M.; Yi, Zhongzhen; Rodgers, Cheryl C; Bollard, Catherine M; Brenner, Malcolm K; Rooney, Cliona M; Heslop, Helen E; Gottschalk, Stephen

    2011-01-01

    Severe chronic active Epstein-Barr virus infection (CAEBV) in T or NK cells is a rare complication of latent EBV infection. CAEBV associated T-cell lymphoproliferative disease (LPD) consists of polyclonal lesions as well as aggressive lymphomas. Here we report such a patient. In addition, we show that this primary CAEBV associated T-cell lymphoma expresses CD70 and is sensitive to killing by CD70-specific T cells, identifying CD70 as a potential immunotherapeutic target for CAEBV-associated T-cell lymphoma. PMID:21994111

  2. EBV latent membrane proteins (LMPs) 1 and 2 as immunotherapeutic targets: LMP-specific CD4+ cytotoxic T cell recognition of EBV-transformed B cell lines.

    PubMed

    Haigh, Tracey A; Lin, Xiaorong; Jia, Hui; Hui, Edwin P; Chan, Anthony T C; Rickinson, Alan B; Taylor, Graham S

    2008-02-01

    The EBV-latent membrane proteins (LMPs) 1 and 2 are among only three viral proteins expressed in EBV-associated Hodgkin's lymphoma and nasopharyngeal carcinoma. Since these tumors are HLA class I and class II-positive, the LMPs could serve as both CD8+ and CD4+ T cell targets. In contrast to CD8 responses, very little is known about CD4 responses to LMPs. In this study, we describe CD4+ T cell clones defining four LMP1- and three LMP2-derived peptide epitopes and their restricting alleles. All clones produced Th1-like cytokines in response to peptide and most killed peptide-loaded target cells by perforin-mediated lysis. Although clones to different epitopes showed different functional avidities in peptide titration assays, avidity per se was a poor predictor of the ability to recognize naturally infected B lymphoblastoid cell lines (LCLs) expressing LMPs at physiologic levels. Some epitopes, particularly within LMP1, consistently mediated strong LCL recognition detectable in cytokine release, cytotoxicity, and outgrowth inhibition assays. Using cyclosporin A to selectively block cytokine release, we found that CD4+ T cell cytotoxicity is the key effector of LCL outgrowth control. We therefore infer that cytotoxic CD4+ T cells to a subset of LMP epitopes could have therapeutic potential against LMP-expressing tumors. PMID:18209060

  3. A prospective large-scale study of methods for the detection of latent Mycobacterium tuberculosis infection in refugee children.

    PubMed

    Lucas, Michaela; Nicol, Pam; McKinnon, Elizabeth; Whidborne, Rebecca; Lucas, Andrew; Thambiran, Aesen; Burgner, David; Waring, Justin; French, Martyn

    2010-05-01

    BACKGROUND Diagnosis of latent tuberculosis infection (LTBI) is a cornerstone of the health assessment of resettled high incidence populations, particularly in children. Two blood-based interferon gamma release assays (IGRAs), T-SPOT.TB and QFT-Gold in-tube (QFT-GIT), have greater sensitivity and specificity than the tuberculin skin test (TST), but their performance as screening tools for LTBI in children, especially refugee children, remains unclear. METHODS 524 African and ethnic Burmese children, including 107 under 3 years of age, were prospectively enrolled in a comparison of the T-SPOT.TB and QFT-GIT. The TST was also performed in 342 of the children. RESULTS The T-SPOT.TB and QFT-GIT had similar rates of positivity (8% and 10%, respectively) and showed good concordance when both tests gave definitive results (kappa=0.78; p<0.0001). However, the IGRAs had significant failure rates: 15% of QFT-GIT gave indeterminate results due to failed mitogen response and 14% of T-SPOT.TB results were inconclusive, largely because of insufficient mononuclear leucocyte yields. Failure of the QFT-GIT mitogen response was associated with African ethnicity and co-morbid infections, particularly with helminths. The TST results showed poor concordance ( approximately 50%) with both IGRAs. CONCLUSIONS It is reasonable to screen using either IGRA with follow-up by the alternative if the test fails. In general, the QFT-GIT is the preferred option for non-African populations but the T-SPOT.TB is recommended when there are epidemiological and/or clinical high risk factors for TB infection. However, both IGRAs have methodological and performance characteristics that limit their usefulness in refugee children, highlighting the need for continued development of screening strategies. PMID:20435869

  4. Decoded calreticulin-deficient embryonic stem cell transcriptome resolves latent cardiophenotype.

    PubMed

    Faustino, Randolph S; Chiriac, Anca; Niederlander, Nicolas J; Nelson, Timothy J; Behfar, Atta; Mishra, Prasanna K; Macura, Slobodan; Michalak, Marek; Terzic, Andre; Perez-Terzic, Carmen

    2010-07-01

    Genomic perturbations that challenge normal signaling at the pluripotent stage may trigger unforeseen ontogenic aberrancies. Anticipatory systems biology identification of transcriptome landscapes that underlie latent phenotypes would offer molecular diagnosis before the onset of symptoms. The purpose of this study was to assess the impact of calreticulin-deficient embryonic stem cell transcriptomes on molecular functions and physiological systems. Bioinformatic surveillance of calreticulin-null stem cells, a monogenic insult model, diagnosed a disruption in transcriptome dynamics, which re-prioritized essential cellular functions. Calreticulin-calibrated signaling axes were uncovered, and network-wide cartography of undifferentiated stem cell transcripts suggested cardiac manifestations. Calreticulin-deficient stem cell-derived cardiac cells verified disorganized sarcomerogenesis, mitochondrial paucity, and cytoarchitectural aberrations to validate calreticulin-dependent network forecasts. Furthermore, magnetic resonance imaging and histopathology detected a ventricular septal defect, revealing organogenic manifestation of calreticulin deletion. Thus, bioinformatic deciphering of a primordial calreticulin-deficient transcriptome decoded at the pluripotent stem cell stage a reconfigured multifunctional molecular registry to anticipate predifferentiation susceptibility toward abnormal cardiophenotype. PMID:20506533

  5. Abandonment of Treatment for Latent Tuberculosis Infection and Socioeconomic Factors in Children and Adolescents: Rio De Janeiro, Brazil

    PubMed Central

    Mendonça, Angela Marcia Cabral; Kritski, Afrânio Lineu; Land, Marcelo Gerardin Poirot; Sant’Anna, Clemax Couto

    2016-01-01

    Background Routine data on the use of isoniazid preventive therapy (IPT) in children and adolescents are scarce in high tuberculosis (TB) burden countries. Objective To describe the factors related to abandonment of IPT in children and adolescents with latent tuberculosis infection (LTBI) receiving routine care. Methods Retrospective (2005–2009) descriptive study of 286 LTBI cases with indication of IPT and serviced at a pediatric hospital in the State of Rio de Janeiro, Brazil. Survival analysis of the risk of abandonment of IPT over six months was performed, including multivariate analysis using the Cox proportional hazards model. Results Out of the 245 cases of LTBI included, 62 abandoned IPT (25.3%; 95% CI: 20%-31%). On multivariate analysis, the variables related to the IPT abandonment hazard ratio were the Human Development Index (HDI) (hazard ratio—HR: 0.004; 0.000–0.569) of the place of residence and the contact with adults that were not undergoing anti-TB treatment (HR: 7.30; 1.00–53.3). Conclusion This study reveals the relevance of the relation of abandonment of IPT to the socioeconomic conditions at the place of residence and poor adherence to the active TB treatment. Educational measures to stimulate preventive treatment of child contacts and curative treatment of index cases should target the full familial setting. PMID:27149514

  6. Interferon Gamma-Based Detection of Latent Tuberculosis Infection in the Border States of Nuevo Leon and Tamaulipas, Mexico

    PubMed Central

    Oren, Eyal; Alatorre-Izaguirre, Gabriela; Vargas-Villarreal, Javier; Moreno-Treviño, Maria Guadalupe; Garcialuna-Martinez, Javier; Gonzalez-Salazar, Francisco

    2015-01-01

    Nearly one-third of the world’s population is infected with latent tuberculosis (LTBI). Tuberculosis (TB) rates in the border states are higher than national rates in both the US and Mexico, with the border accounting for 30% of total registered TB cases in both countries. However, LTBI rates in the general population in Mexican border states are unknown. In this region, LTBI is diagnosed using the tuberculin skin test (TST). New methods of detection more specific than TST have been developed, although there is currently no gold standard for LTBI detection. Our objective is to demonstrate utility of the Quantiferon TB gold In-Tube (QFT-GIT) test compared with the TST to detect LTBI among border populations. This is an observational, cross-sectional study carried out in border areas of the states of Nuevo Leon and Tamaulipas, Mexico. Participants (n = 210) provided a TST and blood sample for the QFT-GIT. Kappa coefficients assessed the agreement between TST and QFT-GIT. Participant characteristics were compared using Fisher exact tests. Thirty-eight percent of participants were diagnosed with LTBI by QFT-GIT. The proportion of LTBI detected using QFT-GIT was almost double [38% (79/210)] that found by TST [19% (39/210)] (P < 0.001). Concordance between TST and QFT-GIT was low (kappa = 0.37). We recommend further studies utilizing the QFT-GIT test to detect LTBI among border populations. PMID:26484340

  7. Change in the Prevalence of Testing for Latent Tuberculosis Infection in the United States: 1999–2012

    PubMed Central

    Vozoris, Nicholas T.; Batt, Jane

    2016-01-01

    Purpose. There is no information on the change in prevalence of latent tuberculosis infection (LTBI) testing in the United States (US) following the introduction of the interferon gamma release assay (IGRA), a new and alternative diagnostic method for LTBI. The purpose of this study was to evaluate potential changes in the prevalence of LTBI testing in the US following the introduction of IGRA. Methods. This was a multiyear cross-sectional study using nationally representative data from the 1999-2000 and 2011-2012 US National Health and Nutrition Examination Surveys. Self-reported prevalence of LTBI testing was estimated among groups known to have increased LTBI risk. Descriptive statistics were used. Results. Compared to 1999-2000, significantly fewer individuals self-reported being tested for LTBI in 2011-2012 among Hispanic Americans (68.0% versus 60.7%, p < 0.0001) and among those with comorbidities (74.7% versus 72.0%, p = 0.02). There were also nonsignificant trends towards less self-reported LTBI testing in 2011-2012 versus 1999-2000 among household contacts of active TB cases, foreign-born individuals, and African Americans. Conclusions. Despite the introduction of IGRA, LTBI testing occurs less frequently in the US among vulnerable groups. Possibly inadequate targeted LTBI testing could result in increased active TB in the US in the future.

  8. High Latent TB Infection Rate and Associated Risk Factors in the Eastern China of Low TB Incidence

    PubMed Central

    Wang, Zhijian; Peng, Hong; Kong, Wen; Zhou, Yang; Shao, Yan; Zhu, Limei; Lu, Wei

    2015-01-01

    Objectives To disclose the associated risk factors for latent tuberculosis infection (LTBI) and the current situation of LTBI in the eastern China. Methods A cross-sectional study was undertaken to evaluate the LTBI rate and risk factors. Results A total of 5305 subjects were finally included, with the IGRA positive rate of 19.98% (1060/5305). The LTBI rates were increasing with age (ORs were in significance from 6.60 to 20.92). Male gender significantly increased the risk of LTBI by 0.52 fold (OR = 1.52). Both smoking and drinking significantly increased the risk of LTBI (OR = 1.83 and OR = 1.67, respectively). Meanwhile, overweight and close contact with tuberculosis were risk factors for LTBI (OR = 1.36 and OR = 2.38, respectively). However, higher level of education and BCG vaccination lowered the risk of LTBI (OR = 0.16 and OR = 0.39, respectively). The multivariate logistic regression showed that age, male gender, smoking, overweight and close contacting with tuberculosis were risk factors for LTBI, but BCG vaccination was a protective factor for LTBI. Conclusions BCG vaccination exerted protective effect on tuberculosis. However, LTBI rate in the Chinese rural area was critical and subjects above 30 years, male, smoking, overweight and close contact with tuberculosis wound be the targets for LTBI screening and source of tuberculosis. PMID:26505997

  9. Interferon Gamma-Based Detection of Latent Tuberculosis Infection in the Border States of Nuevo Leon and Tamaulipas, Mexico.

    PubMed

    Oren, Eyal; Alatorre-Izaguirre, Gabriela; Vargas-Villarreal, Javier; Moreno-Treviño, Maria Guadalupe; Garcialuna-Martinez, Javier; Gonzalez-Salazar, Francisco

    2015-01-01

    Nearly one-third of the world's population is infected with latent tuberculosis (LTBI). Tuberculosis (TB) rates in the border states are higher than national rates in both the US and Mexico, with the border accounting for 30% of total registered TB cases in both countries. However, LTBI rates in the general population in Mexican border states are unknown. In this region, LTBI is diagnosed using the tuberculin skin test (TST). New methods of detection more specific than TST have been developed, although there is currently no gold standard for LTBI detection. Our objective is to demonstrate utility of the Quantiferon TB gold In-Tube (QFT-GIT) test compared with the TST to detect LTBI among border populations. This is an observational, cross-sectional study carried out in border areas of the states of Nuevo Leon and Tamaulipas, Mexico. Participants (n = 210) provided a TST and blood sample for the QFT-GIT. Kappa coefficients assessed the agreement between TST and QFT-GIT. Participant characteristics were compared using Fisher exact tests. Thirty-eight percent of participants were diagnosed with LTBI by QFT-GIT. The proportion of LTBI detected using QFT-GIT was almost double [38% (79/210)] that found by TST [19% (39/210)] (P < 0.001). Concordance between TST and QFT-GIT was low (kappa = 0.37). We recommend further studies utilizing the QFT-GIT test to detect LTBI among border populations. PMID:26484340

  10. Coordinated expansion of both memory T cells and NK cells in response to CMV infection in humans.

    PubMed

    Bayard, Charles; Lepetitcorps, Hélène; Roux, Antoine; Larsen, Martin; Fastenackels, Solène; Salle, Virginie; Vieillard, Vincent; Marchant, Arnaud; Stern, Marc; Boddaert, Jacques; Bajolle, Fanny; Appay, Victor; Sauce, Delphine

    2016-05-01

    NK cells are key players in the fight against persistent viruses. Human cytomegalovirus (HCMV) infection is associated with the presence of a population of CD16(+) CD56(dim) NKG2C(+) NK cells in both acutely and latently infected individuals. Here, we studied the nature of these terminally differentiated NK cells in different human populations infected with HCMV: healthy donors stratified by age, thymectomized individuals, pregnant women suffering from primary CMV infection, and lung transplant patients. Both CD16(+) CD56(dim) NK- and CD8 T-cell phenotypes as well as functional capacities were determined and stratified according to age and/or CMV event. Similarly to T-cell responsiveness, we observe an accumulation over time of NKG2C(+) NK cells, which preferentially expressed CD57. This accumulation is particularly prominent in elderly and amplified further by CMV infection. Latent HCMV infection (without replication) is sufficient for NKG2C(+) CD57(+) NK cells to persist in healthy individuals but is not necessarily required in old age. Collectively, the present work supports the emerging concept that CMV shapes both innate and adaptive immunity in humans. PMID:26910859

  11. Usefulness of interferon-γ release assay for the diagnosis of latent tuberculosis infection in young children

    PubMed Central

    Kim, Young Kwang; Kim, Hae Ryun; Lee, Mi Kyung; Lim, In Seok

    2016-01-01

    Purpose Latent tuberculosis infection (LTBI) in young children may progress to severe active tuberculosis (TB) disease and serve as a reservoir for future transmission of TB disease. There are limited data on interferon-γ release assay (IGRA) performance in young children, which our research aims to address by investigating the usefulness of IGRA for the diagnosis of LTBI. Methods We performed a tuberculin skin test (TST) and IGRA on children who were younger than 18 years and were admitted to Chung-Ang University Hospital during May 2011–June 2015. Blood samples for IGRA were collected, processed, and interpreted according to manufacturer protocol. Results Among 149 children, 31 (20.8%) and 10 (6.7%) were diagnosed with LTBI and active pulmonary TB, respectively. In subjects lacking contact history with active TB patients, TST and IGRA results were positive in 41.4% (29 of 70) and 12.9% (9 of 70) subjects, respectively. The agreement (kappa) of TST and IGRA was 0.123. The control group, consisting of non-TB-infected subjects, showed no correlation between age and changes in interferon-γ concentration after nil antigen, TB-specific antigen, or mitogen stimulation in IGRAs (P=0.384, P=0.176, and P=0.077, respectively). In serial IGRAs, interferon-γ response to TB antigen increased in IGRA-positive LTBI subjects, but did not change considerably in initially IGRA-negative LTBI or control subjects. Conclusion The lack of decrease in interferon-γ response in young children indicates that IGRA could be considered for this age group. Serial IGRA tests might accurately diagnose LTBI in children lacking contact history with active TB patients. PMID:27462354

  12. Evaluation of heat shock proteins for discriminating between latent tuberculosis infection and active tuberculosis: A preliminary report.

    PubMed

    Shekhawat, Seema D; Purohit, Hemant J; Taori, Girdhar M; Daginawala, Hatim F; Kashyap, Rajpal S

    2016-01-01

    The diagnosis of a latent tuberculosis infection (LTBI) is of the utmost concern. The available tests, the tuberculin skin test (TST) and the Quantiferon-TB Gold test (QFT-G) cannot discriminate between active TB and LTBI. Therefore, the aim of the study is to identify new biomarkers that can discriminate between active TB and LTBI and can also assess the risk of the individual developing active TB. In total, 55 blood samples were collected, of which 10 samples were from the active TB infection group, 10 were from the high-risk exposure group, 23 were from the low-risk exposure group, and 12 were from healthy controls living in a non-TB endemic area. A panel of heat shock proteins (Hsps), including host Hsp25, Hsp60, Hsp70, and Hsp90 and Mycobacterium tuberculosis (MTB) Hsp16, were evaluated in all of the collected samples using ELISA. The levels of the host Hsp(s) (Hsp25, Hsp60, Hsp70 and Hsp90) and MTB Hsp16 were significantly (p<0.05) elevated in the active TB group compared to the high-risk exposure group, the low-risk exposure group and the control group. Notably, the levels of the same panel of Hsp(s) were elevated in the high-risk exposure group compared to the low-risk exposure group. On follow-up, out of the 10 high-risk exposure participants, 3 converted into active TB, indicating that this group has the highest risk of developing TB. Thus, the evaluated panel of Hsp(s) can discriminate between LTBI and active TB. They can also identify individuals who are at the highest risk of developing active TB. Because they can be rapidly detected, Hsp(s) have an edge over the existing diagnostic tools for LTBI. The evaluation of these proteins will be useful in designing better diagnostic methods for LTBI. PMID:26300163

  13. Stem Cell Transplant Patients and Fungal Infections

    MedlinePlus

    ... Foodborne, Waterborne, and Environmental Diseases Mycotic Diseases Branch Stem Cell Transplant Patients and Fungal Infections Recommend on Facebook ... Mold . Top of Page Preventing fungal infections in stem cell transplant patients Fungi are difficult to avoid because ...

  14. Mast cells: innate attractors recruiting protective CD8 T cells to sites of cytomegalovirus infection.

    PubMed

    Podlech, Jürgen; Ebert, Stefan; Becker, Marc; Reddehase, Matthias J; Stassen, Michael; Lemmermann, Niels A W

    2015-06-01

    Reactivation of latent cytomegalovirus (CMV) in the transient immunocompromised state after hematoablative treatment is a major concern in patients undergoing hematopoietic cell transplantation (HCT) as a therapy of hematopoietic malignancies. Timely reconstitution of antiviral CD8 T cells and their efficient recruitment to the lungs is crucial for preventing interstitial pneumonia, the most severe disease manifestation of CMV in HCT recipients. Here, we review recent work in a murine model, implicating mast cells (MC) in the control of pulmonary infection. Murine CMV (mCMV) productively infects MC in vivo and triggers their degranulation, resulting in the release of the CC chemokine ligand 5 (CCL5) that attracts CD8 T cells to infiltrate infected tissues. Comparing infection of MC-sufficient C57BL/6 mice and congenic MC-deficient Kit (W-sh/W-sh) "sash" mutants revealed an inverse relation between the number of lung-infiltrating CD8 T cells and viral burden in the lungs. Specifically, reduced lung infiltration by CD8 T cells in "sash" mutants was associated with an impaired infection control. The causal, though indirect, involvement of MC in antiviral control was confirmed by reversion of the deficiency phenotype in "sash" mutants reconstituted with MC. These recent findings predict that efficient MC reconstitution facilitates the control of CMV infection also in immunocompromised HCT recipients. PMID:25648117

  15. Human Type 1 and 17 Responses in Latent Tuberculosis Are Modulated by Coincident Filarial Infection through Cytotoxic T Lymphocyte Antigen–4 and Programmed Death–1

    PubMed Central

    Babu, Subash; Bhat, Sajid Q.; Kumar, N. Pavan; Jayantasri, S.; Rukmani, S.; Kumaran, Paul; Gopi, P. G.; Kolappan, C.; Kumaraswami, V.; Nutman, Thomas B.

    2010-01-01

    Mycobacterium tuberculosis and filarial coinfection is highly prevalent, and the presence of a tissue-invasive helminth may modulate the predominant type 1 T helper (Th1; interferon [IFN]–γ–mediated) response needed to control M. tuberculosis infection. By analyzing the cellular responses to mycobacterial antigens in patients who had latent tuberculosis with or without filarial infection, we were able to demonstrate that filarial infection coincident with M. tuberculosis infection significantly diminishes M. tuberculosis–specific Th1 (interleukin [IL]–12 and IFN-γ) and type 17 T helper (Th17; IL-23 and IL-17) responses related to increased expression of cytotoxic T lymphocyte antigen (CTLA)–4 and programmed death (PD)–1. Blockade of CTLA-4 restored production of both IFN-γ and IL-17, whereas PD-1 blockade restored IFN-γ production only. Thus, coincident filarial infection exerted a profound inhibitory effect on protective mycobacteria-specific Th1 and Th17 responses in latent tuberculosis, suggesting a mechanism by which concomitant filarial (and other systemic helminth) infections predispose to the development of active tuberculosis in humans. PMID:19505258

  16. Hepatic Stellate Cells Inhibit T Cells through Active TGF-β1 from a Cell Surface-Bound Latent TGF-β1/GARP Complex.

    PubMed

    Li, Yan; Kim, Byung-Gyu; Qian, Shiguang; Letterio, John J; Fung, John J; Lu, Lina; Lin, Feng

    2015-09-15

    Hepatic stellate cells (HSCs) inhibit T cells, a process that could help the liver to maintain its immunoprivileged status. HSCs secrete latent TGF-β1, but the detailed mechanisms by which latent TGF-β1 is activated and whether it plays any role in HSC-mediated T cell suppression remain unclear. Glycoprotein A repetitions predominant (GARP) is a surface marker of activated regulatory T cells. GARP binds latent TGF-β1 for its activation, which is critical for regulatory T cells to suppress effector T cells; however, it is still unclear whether GARP is present on HSCs and whether it has any impact on HSC function. In this study, we found that TGF-β1(+/-) HSCs, which produce reduced levels of TGF-β1, showed decreased potency in inhibiting T cells. We also found that pharmaceutical or genetic inhibition of the TGF-β1 signaling pathway reduced the T cell-inhibiting activity of HSCs. Additionally, using isolated primary HSCs, we demonstrated that GARP was constitutively expressed on HSCs. Blocking GARP function or knocking down GARP expression significantly impaired the potency of HSCs to suppress the proliferation of and IFN-γ production from activated T cells, suggesting that GARP is important for HSCs to inhibit T cells. These results demonstrate the unexpected presence of GARP on HSCs and its significance in regard to the ability of HSCs to activate latent TGF-β1 and thereby inhibit T cells. Our study reveals a new mechanism for HSC-mediated immune regulation and potentially for other conditions, such as liver fibrosis, that involve HSC-secreted TGF-β1. PMID:26246140

  17. Productive Lytic Replication of a Recombinant Kaposi's Sarcoma-Associated Herpesvirus in Efficient Primary Infection of Primary Human Endothelial Cells

    PubMed Central

    Gao, Shou-Jiang; Deng, Jian-Hong; Zhou, Fu-Chun

    2003-01-01

    Kaposi's sarcoma-associated herpesvirus (KSHV) is linked to the development of Kaposi's sarcoma (KS), a vascular spindle cell tumor primarily consisting of proliferating endothelial cells. Although KSHV has been shown to infect primary human endothelial cells and convert them into spindle shapes, KSHV infection is largely latent, and efforts to establish a highly efficient and sustainable infection system have been unsuccessful. A recombinant KSHV, BAC36, that has high primary-infection efficiency in 293 cells has been obtained (F. C. Zhou, Y. J. Zhang, J. H. Deng, X. P. Wang, H. Y. Pan, E. Hettler, and S. J. Gao, J. Virol. 76:6185-6196, 2002). BAC36 contains a green fluorescent protein cassette which can be used to conveniently monitor viral infection. Here, we describe the establishment of a KSHV lytic-replication-permissive infection cell model using BAC36 virions to infect primary human umbilical vein endothelial cell (HUVEC) cultures. BAC36 infection of HUVEC cultures has as high as 90% primary-infection efficiency and consists of two phases: a permissive phase, in which the cultures undergo active viral lytic replication, producing a large number of virions and concomitantly resulting in large-scale cell death, and a latent phase, in which the surviving cells from the permissive phase switch into latent infection, with a small number of cells undergoing spontaneous viral lytic replication, and proliferate into bundles of spindle cells with KS slit-like spaces. An assay for determining the KSHV titer in a virus preparation has also been developed. The cell model should be useful for examining KSHV infection and replication, as well as for understanding the development of KS. PMID:12941882

  18. Towards an HIV-1 cure: measuring the latent reservoir

    PubMed Central

    Bruner, Katherine M.; Hosmane, Nina N.; Siliciano, Robert F.

    2015-01-01

    The latent reservoir of HIV-1 in resting memory CD4+ T cells serves as a major barrier to curing HIV-1 infection. While many PCR- and culture-based assays have been used to measure the size of the latent reservoir, correlation between results of different assays is poor and recent studies indicate that no available assay provides an accurate measurement of reservoir size. The discrepancies between assays are a hurdle to clinical trials that aim to measure the efficacy of HIV-1 eradication strategies. Here we describe the advantages and disadvantages of various approaches to measure the latent reservoir. PMID:25747663

  19. Pandemic Influenza A (H1N1) Virus Infection Increases Apoptosis and HIV-1 Replication in HIV-1 Infected Jurkat Cells

    PubMed Central

    Wang, Xue; Tan, Jiying; Biswas, Santanu; Zhao, Jiangqin; Devadas, Krishnakumar; Ye, Zhiping; Hewlett, Indira

    2016-01-01

    Influenza virus infection has a significant impact on public health, since it is a major cause of morbidity and mortality. It is not well-known whether influenza virus infection affects cell death and human immunodeficiency virus (HIV)-1 replication in HIV-1-infected patients. Using a lymphoma cell line, Jurkat, we examined the in vitro effects of pandemic influenza A (H1N1) virus (pH1N1) infection on cell death and HIV-1 RNA production in infected cells. We found that pH1N1 infection increased apoptotic cell death through Fas and Bax-mediated pathways in HIV-1-infected Jurkat cells. Infection with pH1N1 virus could promote HIV-1 RNA production by activating host transcription factors including nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB), nuclear factor of activated T-cells (NFAT) and activator protein 1 (AP-1) through mitogen-activated protein kinases (MAPK) pathways and T-cell antigen receptor (TCR)-related pathways. The replication of HIV-1 latent infection could be reactivated by pH1N1 infection through TCR and apoptotic pathways. These data indicate that HIV-1 replication can be activated by pH1N1 virus in HIV-1-infected cells resulting in induction of cell death through apoptotic pathways. PMID:26848681

  20. Risk of latent TB infection in individuals employed in the healthcare sector in Germany: a multicentre prevalence study

    PubMed Central

    2010-01-01

    Background Healthcare workers are still recognised as a high-risk group for latent TB infection (LTBI). Therefore, the screening of people employed in the healthcare sector for active and LTBI is fundamental to infection control programmes in German hospitals. It was the aim of the study to determine the prevalence and putative risk factors of LTBI. Methods We tested 2028 employees in the healthcare sector with the QuantiFERON-Gold In-tube (QFT-IT) test between December 2005 and May 2009, either in the course of contact tracing or in serial testing of TB high-risk groups following German OSH legislation. Results A positive IGRA was found in 9.9% of the healthcare workers (HCWs). Nurses and physicians showed similar prevalence rates (9.7% to 9.6%). Analysed by occupational group, the highest prevalence was found in administration staff and ancillary nursing staff (17.4% and 16.7%). None of the individuals in the trainee group showed a positive IGRA result. In the different workplaces the observed prevalence was 14.7% in administration, 12.0% in geriatric care, 14.2% in technicians (radiology, laboratory and pathology), 6.5% in admission ward staff and 8.3% in the staff of pulmonary/infectious disease wards. Putative risk factors for LTBI were age (>55 years: OR14.7, 95% CI 5.1-42.1), being foreign-born (OR 1.99, 95% CI 1.4-2.8), TB in the individual's own history (OR 4.96, 95% CI 1.99-12.3) and previous positive TST results (OR 3.5, 95% CI 2.4-4.98). We observed no statistically significant association with gender, BCG vaccination, workplace or profession. Conclusion The prevalence of LTBI in low-incidence countries depends on age. We found no positive IGRA results among trainees in the healthcare sector. Incidence studies are needed to assess the infection risk. Pre-employment screening might be helpful in this endeavour. PMID:20429957

  1. The Prevalence and Incidence of Latent Tuberculosis Infection and Its Associated Factors among Village Doctors in China

    PubMed Central

    Fan, Haiying; Gao, Fangfang; Gao, Fei; Han, Guoxin; Ren, Liping; Song, Yudan; Xiong, Yongchao; Geng, Mengjie; Hou, Yueyun; He, Guoming; Li, Jianbo; Guo, Shufang; Yang, Jun; Yan, Daiqin; Wang, Yali; Gao, Haiyan; An, Jing; Duan, Xiaoyan; Wu, Chunru; Duan, Fengming; Hu, Dongmei; Lu, Kai; Zhao, Yanlin; Rao, Carol Y.; Wang, Yu

    2015-01-01

    Background China is a high tuberculosis (TB) burden country. More than half of acute TB cases first seek medical care in village doctors’ clinics or community health centers. Despite being responsible for patient referral and management, village doctors are not systematically evaluated for TB infection or disease. We assessed prevalence and incidence of latent TB infection (LTBI) among village doctors in China. Methods and Findings A longitudinal study was conducted in Inner Mongolia Autonomous Region. We administered a questionnaire on demographics and risk factors for TB exposure and disease; Tuberculin skin testing (TST) and QuantiFERON-TB Gold in-tube assay (QFT-GIT) was conducted at baseline and repeated 12 months later. We used a logistic regression model to calculate adjusted odds ratios (ORs) for risk factors for TST and QFT-GIT prevalence and incidence. At the time of follow up, 19.5% of the 880 participating village doctors had a positive TST and 46.0% had a positive QFT-GIT result. Factors associated with TST prevalence included having a BCG scar (OR = 1.45, 95%CI 1.03–2.04) and smoking (OR = 1.69, 95%CI 1.17–2.44). Risk factors associated with QFT-GIT prevalence included being male (OR = 2.17, 95%CI 1.63–2.89), below college education (OR=1.42, 95%CI 1.01–1.97), and working for ≥25 years as a village doctor (OR = 1.64, 95%CI 1.12–2.39). The annual incidence of LTBI was 11.4% by TST and 19.1% by QFT-GIT. QFT-GIT conversion was associated with spending 15 minutes or more per patient on average (OR = 2.62, 95%CI 1.39–4.97) and having BCG scar (OR = 0.53, 95%CI 0.28–1.00). Conclusions Prevalence and incidence of LTBI among Chinese village doctors is high. TB infection control measures should be strengthened among village doctors and at village healthcare settings. PMID:25996960

  2. Perinatal hepatitis B virus infection caused by antihepatitis Be positive maternal mononuclear cells.

    PubMed

    Shimizu, H; Mitsuda, T; Fujita, S; Yokota, S

    1991-06-01

    To investigate the infectivity of hepatitis B virus (HBV) from mothers to their newborn offspring, HBV-DNA in plasma and peripheral mononuclear cells from 28 antihepatitis Be positive, hepatitis B surface antigen positive carrier mothers was examined by a highly sensitive polymerase chain reaction/Southern hybridisation technique. HBV specific DNA was detected in three maternal mononuclear cell samples, but was absent in plasma. Two of four infants born to the three mothers with HBV-DNA positive mononuclear cells developed acute or fulminant hepatitis within three months after birth. Two infants were effectively prevented from infection with HBV by combined hepatitis B immunoglobulin/HBV vaccine administration. The 25 infants born to the HBV-DNA negative mothers were free of HBV infection within the next seven months to 3.5 years. These results suggest that latent infection with HBV in maternal mononuclear cells is responsible for perinatal HBV infection. PMID:2053794

  3. QuantiFERON-TB Gold and Tuberculin Skin Test for the Diagnosis of Latent Tuberculosis Infection in Children

    PubMed Central

    Masoumi Asl, Hossein; Alborzi, Abdolvahab; Pourabbas, Bahman; Kalani, Mehdi

    2015-01-01

    Background: Appropriate diagnosis and treatment of latent tuberculosis infection (LTBI) play the most important role in the control of tuberculosis. This study aimed to determine the prevalence of LTBI among healthy tuberculosis unexposed children vaccinated with BCG using the tuberculin skin test (TST) and QuantiFERON TB Gold In-Tube (QFT-GIT) and comparing the agreement between the two tests. Methods: A cross-sectional study was carried out between October 2009 and March 2010 in 24 schools and 11 daycare centers. A total of 967 children were divided into 15 age groups, with a minimum of 64 children per group. Results: The prevalence rates of LTBI with TST were 3.8%, and 2.2% with QFT-GIT. One case was positive in TST and QFT-GIT, 20 cases were QFT-GIT positive, but TST negative and 36 cases were TST positive, but QFT-GIT negative, and finally, 910 cases were negative in both. There was poor agreement between TST and QFT-GIT (1.8%, 95%, CI: 0%-5.3%, k=0.007). The specificity of QFT-GIT in the BCG vaccinated, children aged 1-15 years old, was 97.8% (97.8%, 95% CI: 96.8%-98.8%). After three months, 2/17 (11.8%) of those initially QFT-GIT negative converted, and 10/15 (66%) of those initially QFT-GIT positive reverted. Conclusion: It seems that TST and QFT-GIT are not appropriate tests for the diagnosis of LTBI among healthy tuberculosis unexposed BCG vaccinated children. There was a low reproducibility rate of QFT-GIT. The cause of the the poor agreement requires further studies. PMID:26379347

  4. Exploitation of the Complement System by Oncogenic Kaposi's Sarcoma-Associated Herpesvirus for Cell Survival and Persistent Infection

    PubMed Central

    Lee, Myung-Shin; Jones, Tiffany; Song, Dae-Yong; Jang, Jae-Hyuk; Jung, Jae U.; Gao, Shou-Jiang

    2014-01-01

    During evolution, herpesviruses have developed numerous, and often very ingenious, strategies to counteract efficient host immunity. Specifically, Kaposi's sarcoma-associated herpesvirus (KSHV) eludes host immunity by undergoing a dormant stage, called latency wherein it expresses a minimal number of viral proteins to evade host immune activation. Here, we show that during latency, KSHV hijacks the complement pathway to promote cell survival. We detected strong deposition of complement membrane attack complex C5b-9 and the complement component C3 activated product C3b on Kaposi's sarcoma spindle tumor cells, and on human endothelial cells latently infected by KSHV, TIME-KSHV and TIVE-LTC, but not on their respective uninfected control cells, TIME and TIVE. We further showed that complement activation in latently KSHV-infected cells was mediated by the alternative complement pathway through down-regulation of cell surface complement regulatory proteins CD55 and CD59. Interestingly, complement activation caused minimal cell death but promoted the survival of latently KSHV-infected cells grown in medium depleted of growth factors. We found that complement activation increased STAT3 tyrosine phosphorylation (Y705) of KSHV-infected cells, which was required for the enhanced cell survival. Furthermore, overexpression of either CD55 or CD59 in latently KSHV-infected cells was sufficient to inhibit complement activation, prevent STAT3 Y705 phosphorylation and abolish the enhanced survival of cells cultured in growth factor-depleted condition. Together, these results demonstrate a novel mechanism by which an oncogenic virus subverts and exploits the host innate immune system to promote viral persistent infection. PMID:25254972

  5. Therapeutic doses of irradiation activate viral transcription and induce apoptosis in HIV-1 infected cells.

    PubMed

    Iordanskiy, Sergey; Van Duyne, Rachel; Sampey, Gavin C; Woodson, Caitlin M; Fry, Kelsi; Saifuddin, Mohammed; Guo, Jia; Wu, Yuntao; Romerio, Fabio; Kashanchi, Fatah

    2015-11-01

    The highly active antiretroviral therapy reduces HIV-1 RNA in plasma to undetectable levels. However, the virus continues to persist in the long-lived resting CD4(+) T cells, macrophages and astrocytes which form a viral reservoir in infected individuals. Reactivation of viral transcription is critical since the host immune response in combination with antiretroviral therapy may eradicate the virus. Using the chronically HIV-1 infected T lymphoblastoid and monocytic cell lines, primary quiescent CD4(+) T cells and humanized mice infected with dual-tropic HIV-1 89.6, we examined the effect of various X-ray irradiation (IR) doses (used for HIV-related lymphoma treatment and lower doses) on HIV-1 transcription and viability of infected cells. Treatment of both T cells and monocytes with IR, a well-defined stress signal, led to increase of HIV-1 transcription, as evidenced by the presence of RNA polymerase II and reduction of HDAC1 and methyl transferase SUV39H1 on the HIV-1 promoter. This correlated with the increased GFP signal and elevated level of intracellular HIV-1 RNA in the IR-treated quiescent CD4(+) T cells infected with GFP-encoding HIV-1. Exposition of latently HIV-1infected monocytes treated with PKC agonist bryostatin 1 to IR enhanced transcription activation effect of this latency-reversing agent. Increased HIV-1 replication after IR correlated with higher cell death: the level of phosphorylated Ser46 in p53, responsible for apoptosis induction, was markedly higher in the HIV-1 infected cells following IR treatment. Exposure of HIV-1 infected humanized mice with undetectable viral RNA level to IR resulted in a significant increase of HIV-1 RNA in plasma, lung and brain tissues. Collectively, these data point to the use of low to moderate dose of IR alone or in combination with HIV-1 transcription activators as a potential application for the "Shock and Kill" strategy for latently HIV-1 infected cells. PMID:26184775

  6. A lacZ Reporter-Based Strategy for Rapid Expression Analysis and Target Validation of Mycobacterium tuberculosis Latent Infection Genes.

    PubMed

    Sood, Shivani; Kaur, Satinder; Shrivastava, Rahul

    2016-02-01

    We report a novel lacZ fusion vector and demonstrate its utility for expression analysis of genes associated with Mycobacterium tuberculosis latent infection. The vector contains E. coli (oriE) and mycobacterial (oriM) origins of replication, a kanamycin resistance gene (Km(r)) as selection marker, and a lacZ reporter gene in fusion with MCS for cloning of upstream regulatory sequence of the desired genes. β-galactosidase activity of the vector was standardized for expression analysis under latent mycobacterial conditions using Phsp60, a constitutive mycobacterial promoter, utilizing Mycobacterium smegmatis as model organism. Validation of the vector was done by cloning and expression analysis of PhspX (alpha crystalline) and Picl (isocitrate lyase), promoters from two of the genes shown to be involved in M. tuberculosis persistence. Both genes showed appreciable levels of β-galactosidase expression under hypoxia-induced persistent conditions in comparison to their actively replicating state. Expression analysis of a set of hypothetical genes was also done, of which Rv0628c showed increased expression under persistent conditions. The reported fusion vector and the strategy can be effectively used for short listing and validation of drug targets deduced from various non-conclusive approaches such as bioinformatics and microarray analysis against latent/persistent form of mycobacterial infection. PMID:26597215

  7. Frequent Detection of Latent Tuberculosis Infection among Aged Underground Hard Coal Miners in the Absence of Recent Tuberculosis Exposure

    PubMed Central

    Ringshausen, Felix C.; Nienhaus, Albert; Schablon, Anja; Torres Costa, José; Knoop, Heiko; Hoffmeyer, Frank; Bünger, Jürgen; Merget, Rolf; Harth, Volker; Schultze-Werninghaus, Gerhard; Rohde, Gernot

    2013-01-01

    Background Miners are at particular risk for tuberculosis (TB) infection due to exposure to silica dust and silicosis. The objectives of the present observational cohort study were to determine the prevalence of latent TB infection (LTBI) among aged German underground hard coal miners with silicosis or chronic obstructive pulmonary disease (COPD) using two commercial interferon-gamma release assays (IGRAs) and to compare their performance with respect to predictors of test positivity. Methods Between October 2008 and June 2010, miners were consecutively recruited when routinely attending pneumoconiosis clinics for an expert opinion. Both IGRAs, the QuantiFERON®-TB Gold In-Tube (QFT) and the T-SPOT®.TB (T-SPOT), were performed at baseline. A standardized clinical interview was conducted at baseline and at follow-up. The cohort was prospectively followed regarding the development of active TB for at least two years after inclusion of the last study subject. Independent predictors of IGRA positivity were calculated using logistic regression. Results Among 118 subjects (mean age 75 years), none reported recent exposure to TB. Overall, the QFT and the T-SPOT yielded similarly high rates of positive results (QFT: 46.6%; 95% confidence interval 37.6–55.6%; T-SPOT: 61.0%; 95% confidence interval 52.2–69.8%). Positive results were independently predicted by age ≥80 years and foreign country of birth for both IGRAs. In addition, radiological evidence of prior healed TB increased the chance of a positive QFT result fivefold. While 28 subjects were lost to follow-up, no cases of active TB occurred among 90 subjects during an average follow-up of >2 years. Conclusions Considering the high prevalence of LTBI, the absence of recent TB exposure, and the currently low TB incidence in Germany, our study provides evidence for the persistence of specific interferon-gamma responses even decades after putative exposure. However, the clinical value of current IGRAs among our

  8. Incidence of active mycobacterial infections in Brazilian patients with chronic inflammatory arthritis and negative evaluation for latent tuberculosis infection at baseline - A longitudinal analysis after using TNFα blockers

    PubMed Central

    Gomes, Carina Mori Frade; Terreri, Maria Teresa; de Moraes-Pinto, Maria Isabel; Barbosa, Cássia; Machado, Natália Pereira; Melo, Maria Roberta; Pinheiro, Marcelo Medeiros

    2015-01-01

    Several studies point to the increased risk of reactivation of latent tuberculosis infection (LTBI) in patients with chronic inflammatory arthritis (CIAs) after using tumour necrosis factor (TNF)α blockers. To study the incidence of active mycobacterial infections (aMI) in patients starting TNF α blockers, 262 patients were included in this study: 109 with rheumatoid arthritis (RA), 93 with ankylosing spondylitis (AS), 44 with juvenile idiopathic arthritis (JIA) and 16 with psoriatic arthritis (PsA). All patients had indication for anti-TNF α therapy. Epidemiologic and clinical data were evaluated and a simple X-ray and tuberculin skin test (TST) were performed. The control group included 215 healthy individuals. The follow-up was 48 months to identify cases of aMI. TST positivity was higher in patients with AS (37.6%) than in RA (12.8%), PsA (18.8%) and JIA (6.8%) (p < 0.001). In the control group, TST positivity was 32.7%. Nine (3.43%) patients were diagnosed with aMI. The overall incidence rate of aMI was 86.93/100,000 person-years [95% confidence interval (CI) 23.6-217.9] for patients and 35.79/100,000 person-years (95% CI 12.4-69.6) for control group (p < 0.001). All patients who developed aMI had no evidence of LTBI at the baseline evaluation. Patients with CIA starting TNF α blockers and no evidence of LTBI at baseline, particularly with nonreactive TST, may have higher risk of aMI. PMID:26560983

  9. Parvovirus infection-induced cell death and cell cycle arrest

    PubMed Central

    Chen, Aaron Yun; Qiu, Jianming

    2011-01-01

    The cytopathic effects induced during parvovirus infection have been widely documented. Parvovirus infection-induced cell death is often directly associated with disease outcomes (e.g., anemia resulting from loss of erythroid progenitors during parvovirus B19 infection). Apoptosis is the major form of cell death induced by parvovirus infection. However, nonapoptotic cell death, namely necrosis, has also been reported during infection of the minute virus of mice, parvovirus H-1 and bovine parvovirus. Recent studies have revealed multiple mechanisms underlying the cell death during parvovirus infection. These mechanisms vary in different parvoviruses, although the large nonstructural protein (NS)1 and the small NS proteins (e.g., the 11 kDa of parvovirus B19), as well as replication of the viral genome, are responsible for causing infection-induced cell death. Cell cycle arrest is also common, and contributes to the cytopathic effects induced during parvovirus infection. While viral NS proteins have been indicated to induce cell cycle arrest, increasing evidence suggests that a cellular DNA damage response triggered by an invading single-stranded parvoviral genome is the major inducer of cell cycle arrest in parvovirus-infected cells. Apparently, in response to infection, cell death and cell cycle arrest of parvovirus-infected cells are beneficial to the viral cell lifecycle (e.g., viral DNA replication and virus egress). In this article, we will discuss recent advances in the understanding of the mechanisms underlying parvovirus infection-induced cell death and cell cycle arrest. PMID:21331319

  10. Differentiation-Dependent KLF4 Expression Promotes Lytic Epstein-Barr Virus Infection in Epithelial Cells

    PubMed Central

    Nawandar, Dhananjay M.; Wang, Anqi; Makielski, Kathleen; Lee, Denis; Ma, Shidong; Barlow, Elizabeth; Reusch, Jessica; Jiang, Ru; Wille, Coral K.; Greenspan, Deborah; Greenspan, John S.; Mertz, Janet E.; Hutt-Fletcher, Lindsey; Johannsen, Eric C.; Lambert, Paul F.; Kenney, Shannon C.

    2015-01-01

    Epstein-Barr virus (EBV) is a human herpesvirus associated with B-cell and epithelial cell malignancies. EBV lytically infects normal differentiated oral epithelial cells, where it causes a tongue lesion known as oral hairy leukoplakia (OHL) in immunosuppressed patients. However, the cellular mechanism(s) that enable EBV to establish exclusively lytic infection in normal differentiated oral epithelial cells are not currently understood. Here we show that a cellular transcription factor known to promote epithelial cell differentiation, KLF4, induces differentiation-dependent lytic EBV infection by binding to and activating the two EBV immediate-early gene (BZLF1 and BRLF1) promoters. We demonstrate that latently EBV-infected, telomerase-immortalized normal oral keratinocyte (NOKs) cells undergo lytic viral reactivation confined to the more differentiated cell layers in organotypic raft culture. Furthermore, we show that endogenous KLF4 expression is required for efficient lytic viral reactivation in response to phorbol ester and sodium butyrate treatment in several different EBV-infected epithelial cell lines, and that the combination of KLF4 and another differentiation-dependent cellular transcription factor, BLIMP1, is highly synergistic for inducing lytic EBV infection. We confirm that both KLF4 and BLIMP1 are expressed in differentiated, but not undifferentiated, epithelial cells in normal tongue tissue, and show that KLF4 and BLIMP1 are both expressed in a patient-derived OHL lesion. In contrast, KLF4 protein is not detectably expressed in B cells, where EBV normally enters latent infection, although KLF4 over-expression is sufficient to induce lytic EBV reactivation in Burkitt lymphoma cells. Thus, KLF4, together with BLIMP1, plays a critical role in mediating lytic EBV reactivation in epithelial cells. PMID:26431332

  11. The growth of human HIV-1 infected U937 cells in immune-deprived mice.

    PubMed

    Chernukhin, I V; Chepurnov, A A; Gaidul, K V

    1995-01-01

    We report in vivo growth of human promonocytic cells infected with HIV-1 presented in new mouse model. Cloned U937 cells chronically infected with HIV-1 were grafted in (CBA*C57B1/6)F1 mice deprived of immunity by thymectomia and total body irradiation with subsequent marrow reconstitution. Nine weeks after cell inoculation, HIV-1-positive cells were found only in mice that received an additional single dose of cyclophosphamide (100 mg/kg bw) prior to transplantation, whereas, in mice without further immune deprivation, the complete elimination of cells bearing viral antigen occurred already on the seventh day after transplantation. The approach described may be suitable for in vivo development of antiviral drugs against latent infection in macrophage-like cells which represent a serious problem in therapy of AIDS in humans. PMID:8562863

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

    SciTech Connect

    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.

  13. Impacts of 12-dose regimen for latent tuberculosis infection: Treatment completion rate and cost-effectiveness in Taiwan.

    PubMed

    Huang, Yi-Wen; Yang, Shun-Fa; Yeh, Yen-Po; Tsao, Thomas Chang-Yao; Tsao, Shih-Ming

    2016-08-01

    Treatment of latent tuberculosis infection (LTBI) is essential for eradicating tuberculosis (TB). Moreover, the patient adherence is crucial in determining the effectiveness of TB control. Isoniazid given by DOTS daily for 9 months (9H) is the standard treatment for LTBI in Taiwan. However, the completion rate is low due to the long treatment period and its side effects. The combined regimen using a high dose of rifapentine/isoniazid once weekly for 12 weeks (3HP) has been used as an alternative treatment option for LTBI in the United States. This may result in a higher completion rate. In this pilot study, patient adherence and cost of these 2 treatment regimens were investigated. Thus, we aimed to assess the treatment completion rate and costs of 3HP and compare to those with 9H.Data from 691 cases of LTBI treatments including 590 cases using the conventional regimen and 101 cases with rifapentine/Isoniazid were collected. The cost was the sum of the cost of treatment with Isoniazid for 9 months or with rifapentin/Isoniazid for 3 months of all contacts. The effectiveness was the cost of cases of tuberculosis avoided.In this study, the treatment completion rate for patients prescribed with the 3 months rifapentine/isoniazid regimen (97.03%) was higher than those given the conventional 9-month isoniazid regimen (87.29%) (P <0.001). The cost of 3HP and 9H was US$261.24 and US$717.3, respectively. The cost-effectiveness ratio with isoniazid for 9 months was US$ 15392/avoided 1 case of tuberculosis and US$ 5225/avoided 1 case of tuberculosis with 3HP. In addition, when compared with the conventional regimen, there were fewer patients discontinued with rifapentine/isoniazid regimen due to undesirable side effects.This was the first study to compare the 2 treatment regimens in Taiwan, and it showed that a short-term high-dosage rifapentine/isoniazid treatment regimen reduced costs and resulted in higher treatment completion than the standard LTBI isoniazid treatment

  14. Predictors and Prevalence of Latent Tuberculosis Infection in Patients Receiving Long-Term Hemodialysis and Peritoneal Dialysis

    PubMed Central

    Shu, Chin-Chung; Wu, Vin-Cent; Yang, Feng-Jung; Pan, Sung-Ching; Lai, Tai-Shuan; Wang, Jann-Yuan; Wang, Jann-Tay; Lee, Li-Na

    2012-01-01

    Background Tuberculosis is a common infectious disease in long-term dialysis patients. The prevalence of latent tuberculosis infection (LTBI) in this population is unclear, particularly in those receiving peritoneal dialysis (PD). This study investigated the prevalence of LTBI in patients receiving either hemodialysis (HD) or PD to determine predictors of LTBI and indeterminate results of interferon-gamma release assay. Methods Patients receiving long-term (≥3 months) HD or PD from March 2011 to February 2012 in two medical centers were prospectively enrolled. QuantiFERON-Gold in tube (QFT) test was used to determine the status of LTBI after excluding active tuberculosis. The LTBI prevalence was determined in patients receiving different dialysis modes to obtain predictors of LTBI and QFT-indeterminate results. Results Of 427 patients enrolled (124 PD and 303 HD), 91 (21.3%) were QFT-positive, 316 (74.0%) QFT-negative, and 20 (4.7%) QFT-indeterminate. The prevalence of LTBI was similar in the PD and HD groups. Independent predictors of LTBI were old age (OR: 1.034 [1.013–1.056] per year increment), TB history (OR: 6.467 [1.985–21.066]), and current smoker (OR: 2.675 [1.061–6.747]). Factors associated with indeterminate QFT results were HD (OR: 10.535 [1.336–83.093]), dialysis duration (OR: 1.113 [1.015–1.221] per year increment), anemia (OR: 8.760 [1.014–75.651]), and serum albumin level (OR: 0.244 [0.086–0.693] per 1 g/dL increment). Conclusion More than one-fifth of dialysis patients have LTBI. The LTBI prevalence is similar in PD and HD patients but is higher in the elderly, current smokers, and those with prior TB history. Such patients require closer follow-up. Repeated or alternative test may be required for malnutrition patients who received long length of HD. PMID:22916137

  15. Cell-to-cell signaling and Pseudomonas aeruginosa infections.

    PubMed Central

    Van Delden, C.; Iglewski, B. H.

    1998-01-01

    Pseudomonas aeruginosa is a bacterium responsible for severe nosocomial infections, life-threatening infections in immunocompromised persons, and chronic infections in cystic fibrosis patients. The bacterium's virulence depends on a large number of cell-associated and extracellular factors. Cell-to-cell signaling systems control the expression and allow a coordinated, cell-density-dependent production of many extracellular virulence factors. We discuss the possible role of cell-to-cell signaling in the pathogenesis of P. aeruginosa infections and present a rationale for targeting cell-to-cell signaling systems in the development of new therapeutic approaches. PMID:9866731

  16. Proteolytic activation of latent TGF-beta precedes caspase-3 activation and enhances apoptotic death of lung epithelial cells.

    PubMed

    Solovyan, Victor T; Keski-Oja, Jorma

    2006-05-01

    Transforming growth factors beta (TGF-betas) are multifunctional cytokines, which are secreted in latent forms in large latent TGF-beta complexes (LL-TGF-beta) with subsequent deposition to the extracellular matrix (ECM). While a variety of mechanisms capable of activating latent TGF-beta in vitro have been described, the physiological conditions, which promote the activation of TGF-beta in vivo are poorly understood. Mink lung epithelial cells (Mv1Lu) are a widely used model for evaluation of the effects of exogenous TGF-beta both in transcriptional and growth inhibitor assays. We find here that apoptosis of Mv1Lu cells, induced either by staurosporine or serum deprivation, is accompanied by proteolytic processing of LL-TGF-beta and the activation of endogenous TGF-beta. Activation of TGF-beta preceded caspase-3 activation and was almost completely suppressed by the serine protease inhibitor, AEBSF. Both exogenous and endogenously activated TGF-betas were able to enhance the apoptotic response of Mv1Lu cells leading to potentiation of cell death. Potentiation of cell death by activated TGF-beta was associated with downregulation of Akt and p38 MAPK, which were both activated at the initial stages of Mv1Lu apoptosis and were suppressed by exogenous TGF-beta. Pharmacological interruption of either phosphoinositide-3-kinase (PI-3K)/Akt or p38 MAPK signaling by the specific inhibitors mimicked the effect of TGF-beta leading to potentiation of cell death. Current results suggest that proteolytic activation of endogenous TGF-beta is a component of the apoptotic response, capable of modulating the death of Mv1Lu cells by inhibition of both PI-3K/Akt and p38 MAPK-dependent survival pathways. PMID:16447253

  17. Complete genome sequence of sweet potato latent virus and its relationship to other potyviruses infecting sweet potato

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The complete genome of sweet potato latent virus (SPLV) was determined to be 10,081 nucleotides long, excluding the 3’ poly (A) tail. The genome contains a single large open reading frame encoding a polyprotein of 3,247 amino acids. Its genomic organization is typical of potyviruses and contains mot...

  18. Latent viral infections in young patients with inflammatory diseases treated with biological agents: prevalence of JC virus genotype 2.

    PubMed

    Comar, Manola; Delbue, Serena; Lepore, Loredana; Martelossi, Stefano; Radillo, Oriano; Ronfani, Luca; D'Agaro, Pierlanfranco; Ferrante, Pasquale

    2013-04-01

    Treatment with biological drugs is associated with increased susceptibility to viral infections. Reactivation of JC virus (JCV) and human cytomegalovirus (HCMV) in adults after therapy has been documented. The long-term effects of biological and conventional therapy on human herpesviruses and polyomaviruses infections in young patients were assessed. One hundred eighty-six samples [urine, serum, and blood cells (PBMCs)] from 62 patients (15.8 ± 6.2 years old) with Crohn's disease, ulcerative rectocolitis or juvenile rheumatoid arthritis treated with immunotherapy or conventional therapy for over 12 months were tested by real time PCR. One hundred twenty-four samples (urine and blood) from 62 matched healthy volunteers (13.8 ± 8.6 years old) were included as controls. Sequencing of the JCV viral protein 1 (VP1) and transcriptional control region (TCR) was performed. Herpes simplex virus 1/2 and varicella zoster virus genomes were not detected in any patients, whereas Epstein-Barr virus, HCMV, and human herpesvirus-6 genomes were detected in 4.8%, 3.2%, and 1.6% of the patients, respectively. JCV was detected in 22.6% (14/62) of urine samples from patients and in 8% (5/62) from controls, in 50% (7/14) of sera from patients shedding JCV, and in 71.4% (5/7) of matched PBMCs. There was a significant association between infliximab treatment and excretion of JCV genotype 2. Subclinical infection/reactivation of JCV genotype 2 in young patients during infliximab therapy was demonstrated. Conversely, increased susceptibility to herpesviruses infection was not shown. Future studies are warranted to investigate the effects of JCV reactivation on the health of young patients treated with infliximab. PMID:23364870

  19. T cell responses in dengue viral infections.

    PubMed

    Malavige, Gathsaurie Neelika; Ogg, Graham S

    2013-12-01

    Dengue viral infections are the commonest mosquito borne viral infection in the world, affecting more than 100 countries and 390 million individuals annually. Currently, there are no effective antiviral drugs or an effective vaccine to prevent infection. A main hurdle in developing a safe and effective vaccine has been our poor understanding of the complex nature of the protective immune response in acute dengue infection and the presence of four dengue virus (DV) serotypes that are highly homologous. The role of DV specific T cells in the pathogenesis of severe clinical disease in not clear. It has been speculated that highly cross reactive T cells for the previous infecting heterologous DV serotype, which produce pro-inflammatory cytokines, contribute to disease pathogenesis. These cross reactive T cells are believed to be suboptimal in clearing the infection with the current DV-serotype. However, other studies have shown that cross-reactive DV-specific T cells are absent or present in very low frequency during acute infection, appearing only during the convalescent period in the majority of patients. Furthermore, significant apoptosis of T cells occurs in severe acute clinical disease. Overall therefore, it is unclear what role T cells play in contributing to disease pathogenesis during acute dengue infection. Existing data have been complicated by cross-reactivity in T cells assays. These findings can now be re-evaluated in the light of novel technologies to identify serotype-specific T cell responses. PMID:24220605

  20. PET CT Identifies Reactivation Risk in Cynomolgus Macaques with Latent M. tuberculosis

    PubMed Central

    Lin, Philana Ling; Maiello, Pauline; Gideon, Hannah P.; Cadena, Anthony M.; Rodgers, Mark A.; Gregg, Robert; O’Malley, Melanie; Fillmore, Daniel; Frye, L. James; Rutledge, Tara; DiFazio, Robert M.; Janssen, Christopher; Klein, Edwin; Andersen, Peter L.; Fortune, Sarah M.; Flynn, JoAnne L.

    2016-01-01

    Mycobacterium tuberculosis infection presents across a spectrum in humans, from latent infection to active tuberculosis. Among those with latent tuberculosis, it is now recognized that there is also a spectrum of infection and this likely contributes to the variable risk of reactivation tuberculosis. Here, functional imaging with 18F-fluorodeoxygluose positron emission tomography and computed tomography (PET CT) of cynomolgus macaques with latent M. tuberculosis infection was used to characterize the features of reactivation after tumor necrosis factor (TNF) neutralization and determine which imaging characteristics before TNF neutralization distinguish reactivation risk. PET CT was performed on latently infected macaques (n = 26) before and during the course of TNF neutralization and a separate set of latently infected controls (n = 25). Reactivation occurred in 50% of the latently infected animals receiving TNF neutralizing antibody defined as development of at least one new granuloma in adjacent or distant locations including extrapulmonary sites. Increased lung inflammation measured by PET and the presence of extrapulmonary involvement before TNF neutralization predicted reactivation with 92% sensitivity and specificity. To define the biologic features associated with risk of reactivation, we used these PET CT parameters to identify latently infected animals at high risk for reactivation. High risk animals had higher cumulative lung bacterial burden and higher maximum lesional bacterial burdens, and more T cells producing IL-2, IL-10 and IL-17 in lung granulomas as compared to low risk macaques. In total, these data support that risk of reactivation is associated with lung inflammation and higher bacterial burden in macaques with latent Mtb infection. PMID:27379816

  1. A Step toward Tuberculosis Elimination in a Low-Incidence Country: Successful Diagnosis and Treatment of Latent Tuberculosis Infection in a Refugee Clinic.

    PubMed

    Rennert-May, Elissa; Hansen, Elisabeth; Zadeh, Toktam; Krinke, Valerie; Houston, Stan; Cooper, Ryan

    2016-01-01

    Objectives. Approximately 65 percent of tuberculosis (TB) cases in Canada each year occur from reactivation in foreign-born individuals. Refugees are at high risk after immigration. Routine screening of this population for latent TB infection (LTBI) is generally considered infeasible. We evaluated the outcome of LTBI screening and treatment amongst refugees. Methods. Government-sponsored refugees in Edmonton are seen at the New Canadians' Clinic and screened for TB and LTBI. We reviewed records of patients between 2009 and 2011. Completeness of initial assessment, diagnosis of latent infection, and completion of LTBI treatment were evaluated. Treatment for LTBI was offered when patients had a positive Tuberculin Skin Test (TST) and risk factors for progression to TB. An Interferon-Gamma Release Assay (IGRA) was performed on all other TST positives; treatment is only offered if it was positive. Results. 949 refugees were evaluated. 746 TSTs were read, with 265 positive individuals. IGRA testing was performed in 203 TST positive individuals without other TB risk factors; 110 were positive. LTBI treatment was offered to 147 of 151 eligible patients, 141 accepted, and 103 completed a treatment course. Conclusion. We observed high proportions of patient retention, completion of investigations, and treatment. This care model promises to be a component of effective TB prevention in this high-risk population. PMID:27445565

  2. Gammaherpesvirus Infection of Human Neuronal Cells

    PubMed Central

    Jha, Hem Chandra; Mehta, Devan; Lu, Jie; El-Naccache, Darine; Shukla, Sanket K.; Kovacsics, Colleen; Kolson, Dennis

    2015-01-01

    ABSTRACT Gammaherpesviruses human herpesvirus 4 (HHV4) and HHV8 are two prominent members of the herpesvirus family associated with a number of human cancers. HHV4, also known as Epstein-Barr virus (EBV), a ubiquitous gammaherpesvirus prevalent in 90 to 95% of the human population, is clinically associated with various neurological diseases such as primary central nervous system lymphoma, multiple sclerosis, Alzheimer’s disease, cerebellar ataxia, and encephalitis. However, the possibility that EBV and Kaposi’s sarcoma-associated herpesvirus (KSHV) can directly infect neurons has been largely overlooked. This study has, for the first time, characterized EBV infection in neural cell backgrounds by using the Sh-Sy5y neuroblastoma cell line, teratocarcinoma Ntera2 neurons, and primary human fetal neurons. Furthermore, we also demonstrated KSHV infection of neural Sh-Sy5y cells. These neuronal cells were infected with green fluorescent protein-expressing recombinant EBV or KSHV. Microscopy, genetic analysis, immunofluorescence, and Western blot analyses for specific viral antigens supported and validated the infection of these cells by EBV and KSHV and showed that the infection was efficient and productive. Progeny virus produced from infected neuronal cells efficiently infected fresh neuronal cells, as well as peripheral blood mononuclear cells. Furthermore, acyclovir was effective at inhibiting the production of virus from neuronal cells similar to lymphoblastoid cell lines; this suggests active lytic replication in infected neurons in vitro. These studies represent a potentially new in vitro model of EBV- and KSHV-associated neuronal disease development and pathogenesis. PMID:26628726

  3. c-myc activation renders proliferation of Epstein-Barr virus (EBV)-transformed cells independent of EBV nuclear antigen 2 and latent membrane protein 1.

    PubMed Central

    Polack, A; Hörtnagel, K; Pajic, A; Christoph, B; Baier, B; Falk, M; Mautner, J; Geltinger, C; Bornkamm, G W; Kempkes, B

    1996-01-01

    Two genetic events contribute to the development of endemic Burkitt lymphoma (BL) infection of B lymphocytes with Epstein-Barr virus (EBV) and the activation of the protooncogene c-myc through chromosomal translocation. The viral genes EBV nuclear antigen 2 (EBNA2) and latent membrane protein 1 (LMP1) are essential for transformation of primary human B cells by EBV in vitro; however, these genes are not expressed in BL cells in vivo. To address the question whether c-myc activation might abrogate the requirement of the EBNA2 and LMP1 function, we have introduced an activated c-myc gene into an EBV-transformed cell line in which EBNA2 was rendered estrogen-dependent through fusion with the hormone binding domain of the estrogen receptor. The c-myc gene was placed under the control of regulatory elements of the immunoglobulin kappa locus composed a matrix attachment region, the intron enhancer, and the 3' enhancer. We show here that transfection of a c-myc expression plasmid followed by selection for high MYC expression is capable of inducing continuous proliferation of these cells in the absence of functional EBNA2 and LMP1. c-myc-induced hormone-independent proliferation was associated with a dramatic change in the growth behavior as well as cell surface marker expression of these cells. The typical lymphoblastoid morphology and phenotype of EBV-transformed cells completely changed into that of BL cells in vivo. We conclude that the phenotype of BL cells reflects the expression pattern of viral and cellular genes rather than its germinal center origin. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:8816814

  4. Sulfonation Pathway Inhibitors Block Reactivation of Latent HIV-1

    PubMed Central

    Murry, Jeffrey P.; Godoy, Joseph; Mukim, Amey; Swann, Justine; Bruce, James W.; Ahlquist, Paul; Bosque, Alberto; Planelles, Vicente; Spina, Celsa A.; Young, John A. T.

    2015-01-01

    Long-lived pools of latently infected cells are a significant barrier to the development of a cure for HIV-1 infection. A better understanding of the mechanisms of reactivation from latency is needed to facilitate the development of novel therapies that address this problem. Here we show that chemical inhibitors of the sulfonation pathway prevent virus reactivation, both in latently infected J-Lat and U1 cell lines and in a primary human CD4+ T cell model of latency. In each of these models, sulfonation inhibitors decreased transcription initiation from the HIV-1 promoter. These inhibitors block transcription initiation at a step that lies downstream of nucleosome remodeling and affects RNA polymerase II recruitment to the viral promoter. These results suggest that the sulfonation pathway acts by a novel mechanism to regulate efficient virus transcription initiation during reactivation from latency, and further that augmentation of this pathway could be therapeutically useful. PMID:25310595

  5. Latent class analysis of diagnostic tests for adenovirus, Bordetella pertussis and influenza virus infections in German adults with longer lasting coughs.

    PubMed

    Sobotzki, C; Riffelmann, M; Kennerknecht, N; Hülsse, C; Littmann, M; White, A; Von Kries, R; Wirsing VON König, C H

    2016-03-01

    Laboratory tests in adult outpatients with longer lasting coughs to identify a potential causal pathogen are rarely performed, and there is no gold standard for these diagnostic tests. While the diagnostic validity of serological tests for pertussis is well established their potential contribution for diagnosing adenovirus and influenza virus A and B infections is unclear. A sentinel study into the population-based incidence of longer lasting coughs in adults was done in Rostock (former East Germany) and Krefeld (former West Germany). A total of 971 outpatients who consulted general practitioners or internists were included. Inclusion criteria were coughing for ⩾1 week and no chronic respiratory diseases. We evaluated the performance of polymerase chain reaction (PCR) as well as IgG and IgA serology, applying a latent class model for diagnosing infections with adenovirus, B. pertussis, and influenza virus A and B. The adult outpatients first sought medical attention when they had been coughing for a median of 3 weeks. In this situation, direct detection of infectious agents by PCR had a low sensitivity. Modelling showed that additional serological tests equally improved sensitivity and specificity for diagnosis for adenovirus, B. pertussis and influenza virus A and B infections. The combination of serology and PCR may improve the overall performance of diagnostic tests for B. pertussis and also for adenovirus, and influenza virus A and B infections. PMID:26380914

  6. Activation of latent nucleolus organizers induced by experimental polyploidization in cells of hexaploid wheat Triticum aestivum L.

    PubMed

    Lazareva, E M; Khoudoleeva, O A; Chentsov YuS; Polyakov VYu

    2000-01-01

    The effect of prolonged colchicine-induced polyploidization on activation of latent nucleolus-organizing regions (NOR) of chromosomes was studied in diploid meristematic cells and polyploid root cells of Triticum aestivum L. It has been shown that control diploid and tetraploid cells have maximal number of nucleoli equal to four, which corresponds to the number of nucleolar chromosomes (NC) with active (visualized by staining with AgNO3) NOR (two pairs of homologous chromosomes 1B and 6B). Treatment of wheat seedlings with colchicine for 30 h results in following changes in polyploid cells: (1) impregnation of NOR with silver is observed on homologues of either chromosomes 1A or 5D in all tetraploid metaphase plates (4n, 2x, 4c), which is indicative of the NOR activation on this chromosome in pre-mitotic polyploid interphase; (2) In tetraploid metaphase, NOR in all four homologues of activated chromosomes or in only two of them may be stained; (3) maximal number of nucleoli in tetraploid nuclei is increased till 12, which confirms activation of transcription of additional rRNA gene clusters in polyploids; (4) activation of the rRNA gene expression is induced by the cell polyploidization rather than by colchicine, since in the colchicine-treated diploid cells both maximal number of nucleoli and the number of metaphase chromosomes with active NOR is not changed as compared with control. The obtained data allow us to suggest that structural "separation" of NC in polyploid nuclei stimulates activation of latent NOR. PMID:11093578

  7. Intestinal immune cells in Strongyloides stercoralis infection.

    PubMed Central

    Trajman, A; MacDonald, T T; Elia, C C

    1997-01-01

    BACKGROUND: Strongyloides stercoralis can cause a wide spectrum of disease in man, ranging from a chronic asymptomatic infection to a hyperinfective, often fatal syndrome. In rodents, spontaneous expulsion of Strongyloides spp occurs after experimental infection. Mast cells, goblet cells, and eosinophils have been identified as possible effectors of this expulsion. AIMS: To investigate intestinal histopathology and mucosal immunity in immunocompetent patients with chronic S stercoralis infection. METHODS: Jejunal biopsies were performed in 19 immunocompetent patients with a positive stool examination for S stercoralis and few or no symptoms, and in seven healthy controls. Specimens were processed for histopathological analysis and stained by the immunoperoxidase technique, using the following monoclonal antibodies: CD2, CD3, CD4, CD8, anti-T cell receptor (TcR) gamma/delta, RFD1 and RFD7 (two different macrophage markers), Ki67+ (proliferating) cells, antihuman leucocyte antigen (HLA)-DR, and anticollagen IV. In addition, CD25+ cells, mast cells, IgE expressing cells, calprotectin containing cells, and neutrophil elastase positive cells were stained by the alkaline phosphatase method. RESULTS: Jejunal morphology and the numbers of different T cell subsets, mast cells, IgE expressing cells, eosinophils, and goblet cells were unaffected by S stercoralis infection. Conversely, the numbers of mature macrophages and dividing enterocytes in the crypts were reduced significantly. Crypt enterocytes did not express HLA-DR in both groups. The expression of HLA-DR by villus enterocytes was also comparable in patients and controls. There were no activated (CD25+) cells in the mucosa of either patients or controls. CONCLUSIONS: Compared with seven healthy uninfected volunteers, a group of 19 Brazilians with clinically mild strongyloides infection showed no abnormality of mucosal structure and no increase in non-specific inflammatory cells. Likewise, there was no increase in

  8. Extracellular heat shock protein HSP90{beta} secreted by MG63 osteosarcoma cells inhibits activation of latent TGF-{beta}1

    SciTech Connect

    Suzuki, Shigeki; Kulkarni, Ashok B.

    2010-07-30

    Transforming growth factor-beta 1 (TGF-{beta}1) is secreted as a latent complex, which consists of latency-associated peptide (LAP) and the mature ligand. The release of the mature ligand from LAP usually occurs through conformational change of the latent complex and is therefore considered to be the first step in the activation of the TGF-{beta} signaling pathway. So far, factors such as heat, pH changes, and proteolytic cleavage are reportedly involved in this activation process, but the precise molecular mechanism is still far from clear. Identification and characterization of the cell surface proteins that bind to LAP are important to our understanding of the latent TGF-{beta} activation process. In this study, we have identified heat shock protein 90 {beta} (HSP90{beta}) from the cell surface of the MG63 osteosarcoma cell line as a LAP binding protein. We have also found that MG63 cells secrete HSP90{beta} into extracellular space which inhibits the activation of latent TGF-{beta}1, and that there is a subsequent decrease in cell proliferation. TGF-{beta}1-mediated stimulation of MG63 cells resulted in the increased cell surface expression of HSP90{beta}. Thus, extracellular HSP90{beta} is a negative regulator for the activation of latent TGF-{beta}1 modulating TGF-{beta} signaling in the extracellular domain. -- Research highlights: {yields} Transforming growth factor-beta 1 (TGF-{beta}1) is secreted as a latent complex. {yields} This complex consists of latency-associated peptide (LAP) and the mature ligand. {yields} The release of the mature ligand from LAP is the first step in TGF-{beta} activation. {yields} We identified for the first time a novel mechanism for this activation process. {yields} Heat shock protein 90 {beta} is discovered as a negative regulator for this process.

  9. Latent TB Infection Diagnosis in Population Exposed to TB Subjects in Close and Poor Ventilated High TB Endemic Zone in India

    PubMed Central

    Kashyap, Rajpal S.; Nayak, Amit R.; Gaherwar, Hari M.; Husain, Aliabbas A.; Shekhawat, Seema D.; Jain, Ruchika K.; Panchbhai, Milind S.; Raje, Dhananjay V.; Purohit, Hemant J.; Taori, Girdhar M.; Daginawala, Hatim F.

    2014-01-01

    Background The present study was designed to investigate the utility of Quantiferon TB gold (QFT-G) and Tuberculin skin test (TST) for diagnosis of latent TB infection (LTBI) in high crowding TB endemic zone of Nagpur, India and their comparison with associated risk factors. Methods Out of 342 eligible participants, QFT-G and TST were performed in 162 participants. Results The prevalence of LTBI observed according to QFT-G and TST was 48% and 42% respectively, with an agreement of 52.47%. QFT-G positivity was associated with age while TST positivity was associated with body mass index (BMI). Duration of exposure emerged as a key risk factor significantly associated with both the tests. Conclusion The prevalence of LTBI was quite high in the studied zone as detected by both the evaluated tests and thus, the combination of both the tests will be best predictive for LTBI in such high TB endemic regions. PMID:24614179

  10. Expression of Extremely Low Levels of Thymidine Kinase from an Acyclovir-Resistant Herpes Simplex Virus Mutant Supports Reactivation from Latently Infected Mouse Trigeminal Ganglia▿

    PubMed Central

    Besecker, Michael I.; Furness, Caroline L.; Coen, Donald M.; Griffiths, Anthony

    2007-01-01

    A single-cytosine-deletion in the herpes simplex virus gene encoding thymidine kinase (TK) was previously found in an acyclovir-resistant clinical isolate. A laboratory strain engineered to carry this mutation did not generate sufficient TK activity for detection by plaque autoradiography, which detected 0.25% wild-type activity. However, a drug sensitivity assay suggested that extremely low levels of TK are generated by this virus. The virus was estimated to express 0.09% of wild-type TK activity via a ribosomal frameshift 24 nucleotides upstream of the mutation. Remarkably, this appeared to be sufficient active TK to support a low level of reactivation from latently infected mouse trigeminal ganglia. PMID:17522225

  11. Performance of QuantiFERON-TB Gold In-Tube test and Tuberculin Skin Test for diagnosis of latent tuberculosis infection in BCG vaccinated health care workers

    PubMed Central

    Babayigit, Cenk; Ozer, Burcin; Inandi, Tacettin; Ozer, Cahit; Duran, Nizami; Gocmen, Orhan

    2014-01-01

    Background Tuberculin skin test (TST) has been used for years as an aid in diagnosing latent tuberculosis infection (LTBI) but it suffers from a number of well-documented performance and logistic problems. Quantiferon-TB Gold In Tube test (QFT-GIT) has been reported to have better sensitivity and specifity than TST. In this study, it was aimed to compare the performance of a commercial IFN-γ release assay (QFT-GIT) with TST in the diagnosis of HCWs at risk for latent TB infection in BCG vaccinated population. Material/Methods Hundred healthy volunteer health care workers were enrolled. All were subjected to TST and QFT-GIT. Results were compared among Health Care Workers (HCWs) groups in terms of profession, workplace, working duration. Results TST is affected by previous BCG vaccinations and number of cases with QFT-GIT positivity is increased in accordance with the TST induration diameter range. QFT-GIT result was negative in 17 of 32 TST positive (≥15 mm) cases and positive in 4 of 61 cases whose TST diameters are between 6–14 mm, that is attritutable to previous BCG vaccination(s). It was negative in all cases with TST diameters between 0–5 mm. HCWs with positive QFT-GIT results were significantly older than the ones with negative results. Furthermore duration of work was significantly longer in QFT-GIT positive than in negative HCWs. Conclusions There was a moderate concordance between QFT-GIT and TST, when TST result was defined as positive with a ≥15 mm diameter of induration. We suggest that QFT-GIT can be used as an alternative to TST for detection of LTBI, especially in groups with high risk of LTBI and in population with routine BCG vaccination program. PMID:24681806

  12. The Use of Interferon Gamma Inducible Protein 10 as a Potential Biomarker in the Diagnosis of Latent Tuberculosis Infection in Uganda

    PubMed Central

    Biraro, Irene Andia; Kimuda, Simon; Egesa, Moses; Cose, Stephen; Webb, Emily L.; Joloba, Moses; Smith, Steven G.; Elliott, Alison M.; Dockrell, Hazel M.; Katamba, Achilles

    2016-01-01

    Background In the absence of a gold standard for the diagnosis of latent tuberculosis (TB) infection (LTBI), the current tests available for the diagnosis of LTBI are limited by their inability to differentiate between LTBI and active TB disease. We investigated IP-10 as a potential biomarker for LTBI among household contacts exposed to sputum positive active TB cases. Methods Active TB cases and contacts were recruited into a cohort with six months’ follow-up. Contacts were tested for LTBI using QuantiFERON®-TB Gold In-Tube (QFN) assay and the tuberculin skin test (TST). Baseline supernatants from the QFN assay of 237 contacts and 102 active TB cases were analysed for Mycobacterium tuberculosis (MTB) specific and mitogen specific IP-10 responses. Results Contacts with LTBI (QFN+TST+) had the highest MTB specific IP-10 responses at baseline, compared to uninfected contacts (QFN-TST-) p<0.0001; and active cases, p = 0.01. Using a cut-off of 8,239 pg/ml, MTB specific IP-10 was able to diagnose LTBI with a sensitivity of 87.1% (95% CI, 76.2–94.3) and specificity of 90.9% (95% CI, 81.3–96.6). MTB specific to mitogen specific IP-10 ratio was higher in HIV negative active TB cases, compared to HIV negative latently infected contacts, p = 0.0004. Concentrations of MTB specific IP-10 were higher in contacts with TST conversion (negative at baseline, positive at 6-months) than in those that were persistently TST negative, p = 0.001. Conclusion IP-10 performed well in differentiating contacts with either latent or active TB from those who were uninfected but was not able to differentiate LTBI from active disease except when MTB specific to mitogen specific ratios were used in HIV negative adults. In addition, IP-10 had the potential to diagnose ‘recent TB infection’ in persons classified as having LTBI using the TST. Such individuals with strong IP-10 responses would likely benefit from chemoprophylaxis. PMID:26771653

  13. Treatment of latent syphilis in HIV-infected patients with 10 d of benzylpenicillin G benethamine: a prospective study in Maputo, Mozambique.

    PubMed

    Tattevin, Pierre; Renault, Patrick; Joly, Véronique; Bastos, Rui; Coelho, Elisabeth; Adda, Christian; Ebel, Anne; Yeni, Patrick

    2002-01-01

    Neurosyphilis has been reported in HIV-infected patients previously treated with penicillin G benzathine, which does not achieve treponemicidal levels in cerebrospinal fluid. Therapy combining benzylpenicillin G and its repository form benzylpenicillin G benethamine could be a potentially effective alternative enhanced regimen for treating latent syphilis in HIV-infected patients because peak serum and cerebrospinal fluid concentrations would be achieved early post-administration by the former molecule and sustained for 24 h due to the prolonged half-life of the latter. In this study, 23 asymptomatic HIV and Treponema pallidum co-infected patients received 10 d of combined therapy (2 M IU intramuscular once daily) and were followed up at 3, 6 and 12 months. None experienced side effects or clinical symptoms. Of the 18 patients who were evaluated 1 y later, 8 (44.4%) exhibited serological treatment failure, defined as a positive serum rapid plasma reagin test. In conclusion, a 10-d regimen combining penicillin G and penicillin G benethamine seems to be of no benefit compared to currently recommended treatment. PMID:12064687

  14. Reactivation of latently infected HIV-1 viral reservoirs and correction of aberrant alternative splicing in the LMNA gene via AMPK activation: Common mechanism of action linking HIV-1 latency and Hutchinson-Gilford progeria syndrome.

    PubMed

    Finley, Jahahreeh

    2015-09-01

    Although the use of antiretroviral therapy (ART) has proven highly effective in controlling and suppressing HIV-1 replication, the persistence of latent but replication-competent proviruses in a small subset of CD4(+) memory T cells presents significant challenges to viral eradication from infected individuals. Attempts to eliminate latent reservoirs are epitomized by the 'shock and kill' approach, a strategy involving the combinatorial usage of compounds that influence epigenetic modulation and initiation of proviral transcription. However, efficient regulation of viral pre-mRNA splicing through manipulation of host cell splicing machinery is also indispensible for HIV-1 replication. Interestingly, aberrant alternative splicing of the LMNA gene via the usage of a cryptic splice site has been shown to be the cause of most cases of Hutchinson-Gilford progeria syndrome (HGPS), a rare genetic condition characterized by an accelerated aging phenotype due to the accumulation of a truncated form of lamin A known as progerin. Recent evidence has shown that inhibition of the splicing factors ASF/SF2 (or SRSF1) and SRp55 (or SRSF6) leads to a reduction or an increase in progerin at both the mRNA and protein levels, respectively, thus altering the LMNA pre-mRNA splicing ratio. It is also well-established that during the latter stages of HIV-1 infection, an increase in the production and nuclear export of unspliced viral mRNA is indispensible for efficient HIV-1 replication and that the presence of ASF/SF2 leads to excessive viral pre-mRNA splicing and a reduction of unspliced mRNA, while the presence of SRp55 inhibits viral pre-mRNA splicing and aids in the generation and translation of unspliced HIV-1 mRNAs. The splicing-factor associated protein and putative mitochondrial chaperone p32 has also been shown to inhibit ASF/SF2, increase unspliced HIV-1 viral mRNA, and enhance mitochondrial DNA replication and oxidative phosphorylation. It is our hypothesis that activation of

  15. Latent tuberculosis screening tests and active tuberculosis infection rates in Turkish inflammatory bowel disease patients under anti-tumor necrosis factor therapy

    PubMed Central

    Çekiç, Cem; Aslan, Fatih; Vatansever, Sezgin; Topal, Firdevs; Yüksel, Elif Sarıtaş; Alper, Emrah; Dallı, Ayşe; Ünsal, Belkıs

    2015-01-01

    Background Tumor necrosis factor (TNF)-α inhibitors increase the risk of tuberculosis (TB). The objective of the present study was to determine the rate of active TB infection in inflammatory bowel disease (IBD) patients receiving anti-TNF therapy and to determine the results of their latent TB infection (LTBI) screening tests during the follow up. Methods This is a retrospective observational study of IBD patients receiving anti-TNF therapy. Tuberculin skin test (TST), interferon-γ release assay (IGRA), and chest radiography were used to determine LTBI. Active TB infection rate during anti-TNF treatment was determined. Results Seventy-six IBD patients (25 with ulcerative colitis, 51 with Crohn’s disease; 53 male; mean age 42.0±12.4 years) were included. Forty-four (57.9%) patients received infliximab and 32 (42.1%) adalimumab. Their median duration of anti-TNF therapy was 15 months. Forty-five (59.2%) patients had LTBI and received isoniazid (INH) prophylaxis. During the follow-up period, active TB was identified in 3 (4.7%) patients who were not receiving INH prophylaxis. There was a moderate concordance between the TST and the IGRA (kappa coefficient 0.44, 95% CI 0.24-0.76). Patients with or without immunosuppressive therapy did not differ significantly with respect to TST (P=0.318) and IGRA (P=0.157). Conclusion IBD patients receiving anti-TNF therapy and prophylactic INH have a decreased risk of developing active TB infection. However, despite LTBI screening, the risk of developing active TB infection persists. PMID:25831138

  16. EFFECT OF ENDOTOXIN ON CELLS AND ON THEIR RESPONSE TO INFECTION BY POLIOVIRUSES1

    PubMed Central

    Murphy, William H.; Wisner, Carolyn

    1962-01-01

    Murphy, W. H. (The University of Michigan, Ann Arbor) and C. Wisner. Effect of endotoxin on cells and on their response to infection by polioviruses. J. Bacteriol. 83:649–662. 1962.—The effect of lipopolysaccharide on HeLa-S3, HeLa-Gey, Chang-liver, Maben, and L strain mouse fibroblasts was studied. The liminal dose of endotoxin for the human epithelial cell strains was approximately 250 μg/ml, and their order of sensitivity to endotoxin was: Chang-liver, HeLa-Gey, HeLa-S3, and Maben, the latter being the most resistant. Endotoxin at concentrations exceeding 100 μg/ml was cytotoxic to the L strain of mouse fibroblasts and caused them to markedly agglutinate. Cytotoxic response of cells to endotoxin was not characterized by cell lysis, but by distinctive nuclear changes. In an attempt to demonstrate the metabolic induction of the latent infection of cell cultures by a noncytopathic variant of poliovirus, endotoxin was added at maximal subliminal concentration to cell cultures totally, partially, or fully susceptible to virus. Endotoxin caused a slight but consistent accelerative cytopathic response of cells to infection by cytopathic poliovirus, but failed to induce cytopathic response to infection by submoderate (noncytopathic) poliovirus. Although endotoxin slightly suppressed yields of poliovirus from cells, it did not affect the plating efficiency of virus on cell monolayers. Images PMID:14477444

  17. The Role of Plasmacytoid Dendritic Cells in Innate and Adaptive Immune Responses against Alpha Herpes Virus Infections

    PubMed Central

    Schuster, Philipp; Boscheinen, Jan Bernardin; Tennert, Karin; Schmidt, Barbara

    2011-01-01

    In 1999, two independent groups identified plasmacytoid dendritic cells (PDC) as major type I interferon- (IFN-) producing cells in the blood. Since then, evidence is accumulating that PDC are a multifunctional cell population effectively coordinating innate and adaptive immune responses. This paper focuses on the role of different immune cells and their interactions in the surveillance of alpha herpes virus infections, summarizes current knowledge on PDC surface receptors and their role in direct cell-cell contacts, and develops a risk factor model for the clinical implications of herpes simplex and varicella zoster virus reactivation. Data from studies involving knockout mice and cell-depletion experiments as well as human studies converge into a “spider web”, in which the direct and indirect crosstalk between many cell populations tightly controls acute, latent, and recurrent alpha herpes virus infections. Notably, cells involved in innate immune regulations appear to shape adaptive immune responses more extensively than previously thought. PMID:22312349

  18. Prevalence and Treatment of Latent Tuberculosis Infection Among Newly Arrived Refugees in San Diego County, January 2010–October 2012

    PubMed Central

    Bennett, Rachel J.; Brodine, Stephanie; Waalen, Jill; Moser, Kathleen; Rodwell, Timothy C.

    2014-01-01

    Objectives. We determined the prevalence and treatment rates of latent tuberculosis infection (LTBI) in newly arrived refugees in San Diego County, California, and assessed demographic and clinical characteristics associated with these outcomes. Methods. We analyzed data from LTBI screening results of 4280 refugees resettled in San Diego County between January 2010 and October 2012. Using multivariate logistic regression, we calculated the associations between demographic and clinical risk factors and the outcomes of LTBI diagnosis and LTBI treatment initiation. Results. The prevalence of LTBI was highest among refugees from sub-Saharan Africa (43%) and was associated with current smoking and having a clinical comorbidity that increases the risk for active tuberculosis. Although refugees from sub-Saharan Africa had the highest prevalence of infection, they were significantly less likely to initiate treatment than refugees from the Middle East. Refugees with postsecondary education were significantly more likely to initiate LTBI treatment. Conclusions. Public health strategies are needed to increase treatment rates among high-risk refugees with LTBI. Particular attention is required among refugees from sub-Saharan Africa and those with less education. PMID:24524534

  19. Rhesus lymphocryptovirus latent membrane protein 2A activates {beta}-catenin signaling and inhibits differentiation in epithelial cells

    SciTech Connect

    Siler, Catherine A.; Raab-Traub, Nancy

    2008-08-01

    Rhesus lymphocryptovirus (LCV) is a {gamma}-herpesvirus closely related to Epstein-Barr virus (EBV). The rhesus latent membrane protein 2A (LMP2A) is highly homologous to EBV LMP2A. EBV LMP2A activates the phosphatidylinositol 3-kinase (PI3K) and {beta}-catenin signaling pathways in epithelial cells and affects differentiation. In the present study, the biochemical and biological properties of rhesus LMP2A in epithelial cells were investigated. The expression of rhesus LMP2A in epithelial cells induced Akt activation, GSK3{beta} inactivation and accumulation of {beta}-catenin in the cytoplasm and nucleus. The nuclear translocation, but not accumulation of {beta}-catenin was dependent on Akt activation. Rhesus LMP2A also impaired epithelial cell differentiation; however, this process was not dependent upon Akt activation. A mutant rhesus LMP2A lacking six transmembrane domains functioned similarly to wild-type rhesus LMP2A indicating that the full number of transmembrane domains is not required for effects on {beta}-catenin or cell differentiation. These results underscore the similarity of LCV to EBV and the suitability of the macaque as an animal model for studying EBV pathogenesis.

  20. A framework for the joint modeling of longitudinal diagnostic outcome data and latent infection status: application to investigating the temporal relationship between infection and disease.

    PubMed

    Jones, G; Johnson, W O; Vink, W D; French, N

    2012-06-01

    For many diseases the infection status of individuals cannot be observed directly, but can only be inferred from biomarkers that are subject to measurement error. Diagnosis of infection based on observed symptoms can itself be regarded as an imperfect test of infection status. The temporal relationship between infection and marker outcomes may be complex, especially for recurrent diseases where individuals can experience multiple bouts of infection. We propose an approach that first models the unobserved longitudinal infection status of individuals conditional on relevant covariates, and then jointly models the longitudinal sequence of biomarker outcomes conditional on infection status and covariate information through time, thus resulting in a joint model for longitudinal infection and biomarker sequences. This model can be used to investigate the temporal dynamics of infection, and to evaluate the usefulness of biomarkers for monitoring purposes. Our work is motivated and illustrated by a longitudinal study of bovine digital dermatitis (BDD) on commercial dairy farms in North West England and North Wales, in which the infection of interest is Treponeme spp., and the biomarkers of interest are a continuous enzyme-linked immunosorbent assay test outcome and a dichotomous outcome, foot lesion status. BDD is known to be one of the possible causes of foot lesions in cows. PMID:22004274

  1. HIV Provirus Stably Reproduces Parental Latent and Induced Transcription Phenotypes Regardless of the Chromosomal Integration Site

    PubMed Central

    Hashemi, Farhad B.; Barreto, Kris; Bernhard, Wendy; Hashemi, Pargol; Lomness, Adam

    2016-01-01

    ABSTRACT Understanding the mechanisms of HIV proviral latency is essential for development of a means to eradicate infection and achieve a cure. We have previously described an in vitro latency model that reliably identifies HIV expression phenotypes of infected cells using a dual-fluorescence reporter virus. Our results have demonstrated that ∼50% of infected cells establish latency immediately upon integration of provirus, a phenomenon termed early latency, which appears to occur by mechanisms that are distinct from epigenetic silencing observed with HIV provirus that establishes productive infections. In this study, we have used a mini-dual HIV reporter virus (mdHIV) to compare the long-term stability of provirus produced as early latent or productive infections using Jurkat-Tat T cell clones. Cloned lines bearing mdHIV provirus integrated at different chromosomal locations display unique differences in responsiveness to signaling agonists and chromatin-modifying compounds, and they also produce characteristic expression patterns from the 5′ long terminal repeat (LTR) dsRed and internal EIF1α-enhanced green fluorescent protein (EIF1α-eGFP) reporters. Furthermore, reporter expression profiles of single cell sorted subcultures faithfully reproduce expression profiles identical to that of their original parental population, following prolonged growth in culture, without shifting toward expression patterns resembling that of cell subclones at the time of sorting. Comparison of population dispersion coefficient (CV) and mean fluorescence intensity (MFI) of the subcloned lines showed that both untreated and phorbol myristate acetate (PMA)-ionomycin-stimulated cultures produce expression patterns identical to those of their parental lines. These results indicate that HIV provirus expression characteristics are strongly influenced by the epigenetic landscape at the site of chromosomal integration. IMPORTANCE There is currently considerable interest in development

  2. Dendritic cells cross-present HIV antigens from live as well as apoptotic infected CD4+ T lymphocytes

    NASA Astrophysics Data System (ADS)

    Marañón, Concepción; Desoutter, Jean-François; Hoeffel, Guillaume; Cohen, William; Hanau, Daniel; Hosmalin, Anne

    2004-04-01

    A better understanding of the antigen presentation pathways that lead to CD8+ T cell recognition of HIV epitopes in vivo is needed to achieve better immune control of HIV replication. Here, we show that cross-presentation of very small amounts of HIV proteins from apoptotic infected CD4+ T lymphocytes by dendritic cells to CD8+ T cells is much more efficient than other known HIV presentation pathways, i.e., direct presentation of infectious virus or cross-presentation of defective virus. Unexpectedly, dendritic cells also take up actively antigens into endosomes from live infected CD4+ T lymphocytes and cross-present them as efficiently as antigens derived from apoptotic infected cells. Moreover, live infected CD4+ T cells costimulate cross-presenting dendritic cells in the process. Therefore, dendritic cells can present very small amounts of viral proteins from infected T cells either after apoptosis, which is frequent during HIV infection, or not. Thus, if HIV expression is transiently induced while costimulation is enhanced (for instance after IL-2 and IFN immune therapy), this HIV antigen presentation pathway could be exploited to eradicate latently infected reservoirs, which are poorly recognized by patients' immune systems.

  3. Xanthosine administration does not affect the proportion of epithelial stem cells in bovine mammary tissue, but has a latent negative effect on cell proliferation

    SciTech Connect

    Rauner, Gat; Barash, Itamar

    2014-10-15

    The challenge in manipulating the proportion of somatic stem cells lies in having to override tissue homeostasis. Xanthosine infusion via the teat canal has been reported to augment the number of label-retaining cells in the mammary gland of 3-month-old bovine calves. To further delineate xanthosine's effect on defined stem cells in the mammary gland of heifers—which are candidates for increased prospective milk production following such manipulation—bovine mammary parenchymal tissue was transplanted and integrated into the cleared mammary fat pad of immunodeficient mice. Xanthosine administration for 14 days did not affect the number of label-retaining cells after 10- and 11-week chases. No change in stem cell proportion, analyzed according to CD49f and CD24 expression, was noted. Clone formation and propagation rate of cultured cells, as well as expression of stem cell markers, were also unaffected. In contrast, a latent 50% decrease in bovine mammary cell proliferation rate was observed 11 weeks after xanthosine administration. Tumor development in mice was also limited by xanthosine administration. These effects may have resulted from an initial decrease in expression of the rate-limiting enzyme in guanine synthesis, IMPDH. The data indicate that caution should be exerted when considering xanthosine for stem cell manipulation. - Highlights: • Novel “bovinized“ mouse model for exogenous effects on bovine mammary gland. • Xanthosine did not affect stem cell number/function in bovine mammary gland. • Xanthosine caused an immediate decrease in IMPDH expression in bovine mammary gland. • Xanthosine had latent negative effect on cell proliferation in bovine mammary gland. • Xanthosine administration limited mammary tumor growth.

  4. Prophylactic Use of Ganoderma lucidum Extract May Inhibit Mycobacterium tuberculosis Replication in a New Mouse Model of Spontaneous Latent Tuberculosis Infection

    PubMed Central

    Zhan, Lingjun; Tang, Jun; Lin, Shuzhu; Xu, Yanfeng; Xu, Yuhuan; Qin, Chuan

    2016-01-01

    A mouse model of spontaneous latent tuberculosis infection (LTBI) that mimics LTBI in humans is valuable for drug/vaccine development and the study of tuberculosis. However, most LTBI mouse models require interventions, and a spontaneous LTBI mouse model with a low bacterial load is difficult to establish. In this study, mice were IV-inoculated with 100 CFU Mycobacterium tuberculosis H37Rv, and a persistent LTBI was established with low bacterial loads (0.5~1.5log10 CFU in the lung; < 4log10 CFU in the spleen). Histopathological changes in the lung and spleen were mild during the first 20 weeks post-inoculation. The model was used to demonstrate the comparative effects of prophylactic and therapeutic administration of Ganoderma lucidum extract (spores and spores lipid) in preventing H37Rv replication in both lung and spleen. H37Rv was inhibited with prophylactic use of G. lucidum extract relative to that of the untreated control and therapy groups, and observed in the spleen and lung as early as post-inoculation week 3 and week 5 respectively. H37Rv infection in the therapy group was comparable to that of the untreated control mice. No significant mitigation of pathological changes was observed in either the prophylactic or therapeutic group. Our results suggest that this new LTBI mouse model is an efficient tool of testing anti-tuberculosis drug, the use of G. lucidum extract prior to M. tuberculosis infection may protect the host against bacterial replication to some extent. PMID:26779146

  5. Prophylactic Use of Ganoderma lucidum Extract May Inhibit Mycobacterium tuberculosis Replication in a New Mouse Model of Spontaneous Latent Tuberculosis Infection.

    PubMed

    Zhan, Lingjun; Tang, Jun; Lin, Shuzhu; Xu, Yanfeng; Xu, Yuhuan; Qin, Chuan

    2015-01-01

    A mouse model of spontaneous latent tuberculosis infection (LTBI) that mimics LTBI in humans is valuable for drug/vaccine development and the study of tuberculosis. However, most LTBI mouse models require interventions, and a spontaneous LTBI mouse model with a low bacterial load is difficult to establish. In this study, mice were IV-inoculated with 100 CFU Mycobacterium tuberculosis H37Rv, and a persistent LTBI was established with low bacterial loads (0.5~1.5log10 CFU in the lung; < 4log10 CFU in the spleen). Histopathological changes in the lung and spleen were mild during the first 20 weeks post-inoculation. The model was used to demonstrate the comparative effects of prophylactic and therapeutic administration of Ganoderma lucidum extract (spores and spores lipid) in preventing H37Rv replication in both lung and spleen. H37Rv was inhibited with prophylactic use of G. lucidum extract relative to that of the untreated control and therapy groups, and observed in the spleen and lung as early as post-inoculation week 3 and week 5 respectively. H37Rv infection in the therapy group was comparable to that of the untreated control mice. No significant mitigation of pathological changes was observed in either the prophylactic or therapeutic group. Our results suggest that this new LTBI mouse model is an efficient tool of testing anti-tuberculosis drug, the use of G. lucidum extract prior to M. tuberculosis infection may protect the host against bacterial replication to some extent. PMID:26779146

  6. Infection in sickle cell disease: a review.

    PubMed

    Booth, Catherine; Inusa, Baba; Obaro, Stephen K

    2010-01-01

    Infection is a significant contributor to morbidity and mortality in sickle cell disease (SCD). The sickle gene confers an increased susceptibility to infection, especially to certain bacterial pathogens, and at the same time infection provokes a cascade of SCD-specific pathophysiological changes. Historically, infection is a major cause of mortality in SCD, particularly in children, and it was implicated in 20-50% of deaths in prospective cohort studies over the last 20 years. Worldwide, it remains the leading cause of death, particularly in less developed nations. In developed countries, measures to prevent and effectively treat infection have made a substantial contribution to improvements in survival and quality of life, and are continually being developed and extended. However, progress continues to lag in less developed countries where the patterns of morbidity and mortality are less well defined and implementation of preventive care is poor. This review provides an overview of how SCD increases susceptibility to infections, the underlying mechanisms for susceptibility to specific pathogens, and how infection modifies the outcome of SCD. It also highlights the challenges in reducing the global burden of mortality in SCD. PMID:19497774

  7. Alteration of cell cycle progression by Sindbis virus infection

    SciTech Connect

    Yi, Ruirong; Saito, Kengo; Isegawa, Naohisa; Shirasawa, Hiroshi

    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.

  8. Increased poly(ADP-ribose)polymerase activity in cells infected by human immunodeficiency virus type-1.

    PubMed

    Furlini, G; Re, M C; La Placa, M

    1991-04-01

    Poly(ADP-ribose)polymerase is a chromatin-bound enzyme which is activated by free DNA ends and is therefore stimulated by a variety of DNA-damaging agents. The enzyme transfers the ADP moiety of NAD to nuclear proteins to create protein-bound ADP-ribose polymers. Under conditions favouring an accelerated poly(ADP-ribose) polymer formation, the enzyme may exhaust cellular NAD pools. At the same time, or shortly thereafter ATP levels drop and cell viability eventually declines. As a series of chemical and physical agents which may play a role in activating latent HIV-1 infection or favouring HIV-1 replication, have a DNA-damaging activity, we investigated the behaviour of poly(ADP-ribose)polymerase activity in various types of HIV-1-infected cells. The results obtained show that HIV-1-infected cells to possess an increased poly(ADP-ribosol)ating activity together with an accentuated fragmentation of cellular DNA which are associated with the time course of HIV-1 replication. These data give circumstantial support to the hypothesis that a NAD-depdendent cellular suicide response to DNA damage, could play a role in the death of HIV-1 infected cells. In this respect, the impared immunocompetence of HIV-1-infected patients could bear some resemblance to immune attribution that sometimes accompanies some inborn errors affecting DNA precursor metabolism and DNA integrity. PMID:1906973

  9. Epstein-Barr virus-positive and -negative B-cell lines can be infected with human immunodeficiency virus types 1 and 2.

    PubMed Central

    Monroe, J E; Calender, A; Mulder, C

    1988-01-01

    Human immunodeficiency virus type 1 (HIV-1) can infect CD4+ lymphocytes, monocytes-macrophages, and various other cell lines, including B-cell lines. To study the parameters of B-cell infections, we examined the susceptibility of 24 B-lymphoid cell lines to both HIV-1 and HIV-2 infections. These cell lines included a series of Epstein-Barr virus (EBV) genome-negative Burkitt's lymphoma cell lines and their EBV-converted counterparts. To infect these cells we used two HIV-1 isolates and one HIV-2 isolate. Infections were monitored with a cytoplasmic RNA dot-blot and a syncytium assay. HIV infection was also studied by a novel method based on electrophoresis of DNA liberated from cells that were lysed in situ in the well of an agarose gel. All human B-cell lines could be infected with HIV-1, regardless of the presence of EBV genomes; thus, EBV infection had no major effect on HIV susceptibility of B-cell lines. Integrated proviral HIV genomes could be detected by Southern blot analysis of DNA extracted from long-term, non-HIV-producing B-cell lines. This study suggests that B-lymphoid cells may serve as reservoirs for latent or persistent HIV infections in vivo, even in the absence of EBV infection. Images PMID:2841499

  10. NKT Cell Immune Responses to Viral Infection

    PubMed Central

    Tessmer, Marlowe S.; Fatima, Ayesha; Paget, Christophe; Trottein, François; Brossay, Laurent

    2010-01-01

    Background Natural killer T (NKT) cells are a heterogeneous population of innate T cells that have attracted recent interest because of their potential to regulate immune responses to a variety of pathogens. The most widely studied NKT cell subset is the invariant (i)NKT cells that recognize glycolipids in the context of the CD1d molecule. The multifaceted methods of activation iNKT cells possess and their ability to produce regulatory cytokines has made them a primary target for therapeutic studies. Objective/Methods This review gives insight into the roles of iNKT cells during infectious diseases, particularly viral infections. We also highlight the different mechanisms leading to iNKT cell activation in response to pathogens. Conclusions The iNKT cell versatility allows them to detect and respond to several viral infections. However, therapeutic approaches to specifically target iNKT cells will require additional research. Notably, examination of the roles of non-invariant NKT cells in response to pathogens warrant further investigations. PMID:19236234

  11. Glycosaminoglycan receptors facilitate infection of mammalian cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A growing list of viruses has been reported to use more than one receptor for binding and internalization during infection of the host cell. Sialic acid residues or glycosaminoglycans, such as heparin sulfate, frequently function in this scenario, as a first contact, charge based, low affinity bindi...

  12. The Functional Response of B Cells to Antigenic Stimulation: A Preliminary Report of Latent Tuberculosis.

    PubMed

    du Plessis, Willem J; Kleynhans, Léanie; du Plessis, Nelita; Stanley, Kim; Malherbe, Stephanus T; Maasdorp, Elizna; Ronacher, Katharina; Chegou, Novel N; Walzl, Gerhard; Loxton, Andre G

    2016-01-01

    Mycobacterium tuberculosis (M.tb) remains a successful pathogen, causing tuberculosis disease numbers to constantly increase. Although great progress has been made in delineating the disease, the host-pathogen interaction is incompletely described. B cells have shown to function as both effectors and regulators of immunity via non-humoral methods in both innate and adaptive immune settings. Here we assessed specific B cell functional interaction following stimulation with a broad range of antigens within the LTBI milieu. Our results indicate that B cells readily produce pro- and anti-inflammatory cytokines (including IL-1β, IL-10, IL-17, IL-21 and TNF-α) in response to stimulation. TLR4 and TLR9 based stimulations achieved the greatest secreted cytokine-production response and BCG stimulation displayed a clear preference for inducing IL-1β production. We also show that the cytokines produced by B cells are implicated strongly in cell-mediated communication and that plasma (memory) B cells (CD19+CD27+CD138+) is the subset with the greatest contribution to cytokine production. Collectively our data provides insight into B cell responses, where they are implicated in and quantifies responses from specific B cell phenotypes. These findings warrant further functional B cell research with a focus on specific B cell phenotypes under conditions of active TB disease to further our knowledge about the contribution of various cell subsets which could have implications for future vaccine development or refined B cell orientated treatment in the health setting. PMID:27050308

  13. The Functional Response of B Cells to Antigenic Stimulation: A Preliminary Report of Latent Tuberculosis

    PubMed Central

    du Plessis, Willem J.; Kleynhans, Léanie; du Plessis, Nelita; Stanley, Kim; Malherbe, Stephanus T.; Maasdorp, Elizna; Ronacher, Katharina; Chegou, Novel N.; Walzl, Gerhard; Loxton, Andre G.

    2016-01-01

    Mycobacterium tuberculosis (M.tb) remains a successful pathogen, causing tuberculosis disease numbers to constantly increase. Although great progress has been made in delineating the disease, the host-pathogen interaction is incompletely described. B cells have shown to function as both effectors and regulators of immunity via non-humoral methods in both innate and adaptive immune settings. Here we assessed specific B cell functional interaction following stimulation with a broad range of antigens within the LTBI milieu. Our results indicate that B cells readily produce pro- and anti-inflammatory cytokines (including IL-1β, IL-10, IL-17, IL-21 and TNF-α) in response to stimulation. TLR4 and TLR9 based stimulations achieved the greatest secreted cytokine-production response and BCG stimulation displayed a clear preference for inducing IL-1β production. We also show that the cytokines produced by B cells are implicated strongly in cell-mediated communication and that plasma (memory) B cells (CD19+CD27+CD138+) is the subset with the greatest contribution to cytokine production. Collectively our data provides insight into B cell responses, where they are implicated in and quantifies responses from specific B cell phenotypes. These findings warrant further functional B cell research with a focus on specific B cell phenotypes under conditions of active TB disease to further our knowledge about the contribution of various cell subsets which could have implications for future vaccine development or refined B cell orientated treatment in the health setting. PMID:27050308

  14. Cells in Dengue Virus Infection In Vivo

    PubMed Central

    Noisakran, Sansanee; Onlamoon, Nattawat; Songprakhon, Pucharee; Hsiao, Hui-Mien; Chokephaibulkit, Kulkanya; Perng, Guey Chuen

    2010-01-01

    Dengue has been recognized as one of the most important vector-borne emerging infectious diseases globally. Though dengue normally causes a self-limiting infection, some patients may develop a life-threatening illness, dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS). The reason why DHF/DSS occurs in certain individuals is unclear. Studies in the endemic regions suggest that the preexisting antibodies are a risk factor for DHF/DSS. Viremia and thrombocytopenia are the key clinical features of dengue virus infection in patients. The amounts of virus circulating in patients are highly correlated with severe dengue disease, DHF/DSS. Also, the disturbance, mainly a transient depression, of hematological cells is a critical clinical finding in acute dengue patients. However, the cells responsible for the dengue viremia are unresolved in spite of the intensive efforts been made. Dengue virus appears to replicate and proliferate in many adapted cell lines, but these in vitro properties are extremely difficult to be reproduced in primary cells or in vivo. This paper summarizes reports on the permissive cells in vitro and in vivo and suggests a hematological cell lineage for dengue virus infection in vivo, with the hope that a new focus will shed light on further understanding of the complexities of dengue disease. PMID:22331984

  15. Latent membrane protein 1 is critical for efficient growth transformation of human B cells by epstein-barr virus.

    PubMed

    Dirmeier, Ulrike; Neuhierl, Bernhard; Kilger, Ellen; Reisbach, Gilbert; Sandberg, Mark L; Hammerschmidt, Wolfgang

    2003-06-01

    The EBV latent membrane protein 1 (LMP1) is an integral membrane protein that acts like a constitutively activated receptor. LMP1 interacts with members of the tumor necrosis factor receptor-associated factor family, as well as with tumor necrosis factor receptor-associated death domain, resulting in induction of nuclear factor-kappaB, the p38 mitogen-activated protein kinase pathway, and the c-Jun NH(2)-terminal kinase activator protein 1-signaling cascade. The binding of Janus kinase 3 results in activation of signal transducers and activators of transcription. The domain structure of LMP1 has been mapped extensively, but the quantitative contribution of distinct LMP1 domains to the efficiency of B-cell proliferation by EBV has not been determined. On the basis of the maxi-EBV system, which allows us to introduce and study mutations in the context of the complete EBV genome, a panel of 10 EBV mutants with alterations in the LMP1 gene locus was established. The mutant EBVs were tested for their efficiency to induce and maintain proliferation of clonal B-cell lines in vitro. Surprisingly and with reduced frequency, EBV mutants which deleted LMP1's COOH terminus, transmembrane domains, or the entire open reading frame were able to generate proliferating B-cell clones that were dependent on the presence of human fibroblast feeder cells. A B-cell clone carrying the LMP1-null mutant EBV genome was also analyzed for oncogenicity in severe combined immunodeficiency mice. Our results demonstrate that LMP1 is critical but not mandatory for the generation of proliferating B cells in vitro. LMP1 functions greatly contribute to EBV's transformation potential and appear essential for its oncogenicity in severe combined immunodeficiency mice. PMID:12782607

  16. Role of neutralizing antibodies and T-cells in pathogenesis of herpes simplex virus infection in congenitally athymic mice.

    PubMed

    Kapoor, A K; Buckmaster, A; Nash, A A; Field, H J; Wildy, P

    1982-11-01

    Congenitally athymic nude mice were infected with 10(4) p.f.u. herpes simplex type 1 (strain SC16). Following the passive transfer of neutralizing monoclonal antibodies (AP7, AP8 and AP12) it was observed that AP7 alone reduced the virus infectivity in the nervous system; AP8 and AP12 failed to protect mice probably due to poor in vivo binding to the neutralization site on the virus. Latent ganglionic infection could be established in nude mice following adoptive transfer of optimum number (2 x 10(7) cells/mouse) of immune lymph node cells from day 7 herpes virus-infected hairy immunocompetent donor mice. Moreover, in some of the immune lymph node cell protected nudes, latency could be maintained even in complete absence of neutralizing antibodies. Results of ear-ablation experiments revealed that removal of primary source of infection after day 5 of infection reduced the amount of virus in the ganglia and spinal cord. Acute neurological infection was not detected following transfer of protective anti-gp-D neutralizing antibody (LP2) in combination with removal of infected pinna. These data suggest that continuous seeding of virus occurs in related ganglia via the axonal route from infected ear pinna. It appears that local T-cell-mediated immune mechanisms are involved in maintenance of latency. PMID:6984425

  17. Vpr Enhances Tumor Necrosis Factor Production by HIV-1-Infected T Cells

    PubMed Central

    Roesch, Ferdinand; Richard, Léa; Rua, Réjane; Porrot, Françoise; Casartelli, Nicoletta

    2015-01-01

    ABSTRACT The HIV-1 accessory protein Vpr displays different activities potentially impacting viral replication, including the arrest of the cell cycle in the G2 phase and the stimulation of apoptosis and DNA damage response pathways. Vpr also modulates cytokine production by infected cells, but this property remains partly characterized. Here, we investigated the effect of Vpr on the production of the proinflammatory cytokine tumor necrosis factor (TNF). We report that Vpr significantly increases TNF secretion by infected lymphocytes. De novo production of Vpr is required for this effect. Vpr mutants known to be defective for G2 cell cycle arrest induce lower levels of TNF secretion, suggesting a link between these two functions. Silencing experiments and the use of chemical inhibitors further implicated the cellular proteins DDB1 and TAK1 in this activity of Vpr. TNF secreted by HIV-1-infected cells triggers NF-κB activity in bystander cells and allows viral reactivation in a model of latently infected cells. Thus, the stimulation of the proinflammatory pathway by Vpr may impact HIV-1 replication in vivo. IMPORTANCE The role of the HIV-1 accessory protein Vpr remains only partially characterized. This protein is important for viral pathogenesis in infected individuals but is dispensable for viral replication in most cell culture systems. Some of the functions described for Vpr remain controversial. In particular, it remains unclear whether Vpr promotes or instead prevents proinflammatory and antiviral immune responses. In this report, we show that Vpr promotes the release of TNF, a proinflammatory cytokine associated with rapid disease progression. Using Vpr mutants or inhibiting selected cellular genes, we show that the cellular proteins DDB1 and TAK1 are involved in the release of TNF by HIV-infected cells. This report provides novel insights into how Vpr manipulates TNF production and helps clarify the role of Vpr in innate immune responses and inflammation

  18. Should all patients undergoing treatment with biologic agents be screened annually for latent tuberculosis infection with an interferon gamma release assay?

    PubMed

    Johnson, M G; Bialas, R W; Hall, R P; Stout, J E

    2016-08-01

    Systemic biologic therapy has become commonplace for the treatment of a variety of inflammatory dermatologic conditions, particularly psoriasis. Screening for latent tuberculosis infection (LTBI) is recommended prior to initiation of systemic biologic agents, and an interferon gamma release assays (IGRA) is often used as the screening modality. Annual screening for LTBI is also recommended for patients while on systemic biologic therapy, but the literature does not clearly support how often screening should be performed. In addition, serial testing with IGRAs, particularly among low-risk populations without any new tuberculosis (TB) exposures, has proven to be unreliable with frequent reversions and conversions. We propose that in low-incidence TB regions, repeat LTBI screening should only be considered for patients on systemic biologic therapy if any new TB exposures occurred since initial LTBI screening was performed prior to starting biologic therapy. This strategy aims to reduce false-positive LTBI testing that can expose patients to hazardous antibiotics and result in the unnecessary interruption of systemic biologic therapy. PMID:26652171

  19. A Subgroup of Latently Mycobacterium tuberculosis Infected Individuals Is Characterized by Consistently Elevated IgA Responses to Several Mycobacterial Antigens

    PubMed Central

    Baumann, Ralf; Kaempfer, Susanne; Chegou, Novel N.; Oehlmann, Wulf; Spallek, Ralf; Loxton, André G.; van Helden, Paul D.; Black, Gillian F.; Singh, Mahavir; Walzl, Gerhard

    2015-01-01

    Elevated antibody responses to Mycobacterium tuberculosis antigens in individuals with latent infection (LTBI) have previously been linked to an increased risk for progression to active disease. Studies in the field focussed mainly on IgG antibodies. In the present study, IgA and/or IgG responses to the mycobacterial protein antigens AlaDH, NarL, 19 kDa, PstS3, and MPT83 were determined in a blinded fashion in sera from 53 LTBI controls, 14 healthy controls, and 42 active TB subjects. Among controls, we found that elevated IgA levels against all investigated antigens were not randomly distributed but concentrated on a subgroup of <30%—with particular high levels in a small subgroup of ~5% comprising one progressor to active TB. Based on a specificity of 100%, anti-NarL IgA antibodies achieved with 78.6% sensitivity the highest accuracy for the detection of active TB compared to healthy controls. In conclusion, the consistently elevated IgA levels in a subgroup of controls suggest higher mycobacterial load, a risk factor for progression to active TB, and together with high IgG levels may have prognostic potential and should be investigated in future large scale studies. The novel antigen NarL may also be promising for the antibody-based diagnosis of active TB cases. PMID:26347586

  20. The GARP/Latent TGF-β1 complex on Treg cells modulates the induction of peripherally derived Treg cells during oral tolerance.

    PubMed

    Edwards, Justin P; Hand, Timothy W; Morais da Fonseca, Denise; Glass, Deborah D; Belkaid, Yasmine; Shevach, Ethan M

    2016-06-01

    Treg cells can secrete latent TGF-β1 (LTGF-β1), but can also utilize an alternative pathway for transport and expression of LTGF-β1 on the cell surface in which LTGF-β1 is coupled to a distinct LTGF-β binding protein termed glycoprotein A repetitions predominant (GARP)/LRRC32. The function of the GARP/LTGF-β1 complex has remained elusive. Here, we examine in vivo the roles of GARP and TGF-β1 in the induction of oral tolerance. When Foxp3(-) OT-II T cells were transferred to wild-type recipient mice followed by OVA feeding, the conversion of Foxp3(-) to Foxp3(+) OT-II cells was dependent on recipient Treg cells. Neutralization of IL-2 in the recipient mice also abrogated this conversion. The GARP/LTGF-β1 complex on recipient Treg cells, but not dendritic cell-derived TGF-β1, was required for efficient induction of Foxp3(+) T cells and for the suppression of delayed hypersensitivity. Expression of the integrin αvβ8 by Treg cells (or T cells) in the recipients was dispensable for induction of Foxp3 expression. Transient depletion of the bacterial flora enhanced the development of oral tolerance by expanding Treg cells with enhanced expression of the GARP/LTGF-β1 complex. PMID:27062243

  1. CRISPR-mediated Activation of Latent HIV-1 Expression.

    PubMed

    Limsirichai, Prajit; Gaj, Thomas; Schaffer, David V

    2016-03-01

    Complete eradication of HIV-1 infection is impeded by the existence of cells that harbor chromosomally integrated but transcriptionally inactive provirus. These cells can persist for years without producing viral progeny, rendering them refractory to immune surveillance and antiretroviral therapy and providing a permanent reservoir for the stochastic reactivation and reseeding of HIV-1. Strategies for purging this latent reservoir are thus needed to eradicate infection. Here, we show that engineered transcriptional activation systems based on CRISPR/Cas9 can be harnessed to activate viral gene expression in cell line models of HIV-1 latency. We further demonstrate that complementing Cas9 activators with latency-reversing compounds can enhance latent HIV-1 transcription and that epigenome modulation using CRISPR-based acetyltransferases can also promote viral gene activation. Collectively, these results demonstrate that CRISPR systems are potentially effective tools for inducing latent HIV-1 expression and that their use, in combination with antiretroviral therapy, could lead to improved therapies for HIV-1 infection. PMID:26607397

  2. Detection of Mycobacterium tuberculosis Peptides in the Exosomes of Patients with Active and Latent M. tuberculosis Infection Using MRM-MS

    PubMed Central

    Kruh-Garcia, Nicole A.; Wolfe, Lisa M.; Chaisson, Lelia H.; Worodria, William O.; Nahid, Payam; Schorey, Jeff S.; Davis, J. Lucian; Dobos, Karen M.

    2014-01-01

    The identification of easily measured, accurate diagnostic biomarkers for active tuberculosis (TB) will have a significant impact on global TB control efforts. Because of the host and pathogen complexities involved in TB pathogenesis, identifying a single biomarker that is adequately sensitive and specific continues to be a major hurdle. Our previous studies in models of TB demonstrated that exosomes, such as those released from infected macrophages, contain mycobacterial products, including many Mtb proteins. In this report, we describe the development of targeted proteomics assays employing multiplexed multiple reaction monitoring mass spectrometry (MRM-MS) in order to allow us to follow those proteins previously identified by western blot or shotgun mass spectrometry, and enhance biomarker discovery to include detection of Mtb proteins in human serum exosomes. Targeted MRM-MS assays were applied to exosomes isolated from human serum samples obtained from culture-confirmed active TB patients to detect 76 peptides representing 33 unique Mtb proteins. Our studies revealed the first identification of bacteria-derived biomarker candidates of active TB in exosomes from human serum. Twenty of the 33 proteins targeted for detection were found in the exosomes of TB patients, and included multiple peptides from 8 proteins (Antigen 85B, Antigen 85C, Apa, BfrB, GlcB, HspX, KatG, and Mpt64). Interestingly, all of these proteins are known mycobacterial adhesins and/or proteins that contribute to the intracellular survival of Mtb. These proteins will be included as target analytes in future validation studies as they may serve as markers for persistent active and latent Mtb infection. In summary, this work is the first step in identifying a unique and specific panel of Mtb peptide biomarkers encapsulated in exosomes and reveals complex biomarker patterns across a spectrum of TB disease states. PMID:25080351

  3. Primary B Lymphocytes Infected with Kaposi's Sarcoma-Associated Herpesvirus Can Be Expanded In Vitro and Are Recognized by LANA-Specific CD4+ T Cells

    PubMed Central

    Nicol, Samantha M.; Sabbah, Shereen; Brulois, Kevin F.; Jung, Jae U.; Bell, Andrew I.

    2016-01-01

    ABSTRACT Kaposi's sarcoma-associated herpesvirus (KSHV) has tropism for B lymphocytes, in which it establishes latency, and can also cause lymphoproliferative disorders of these cells manifesting as primary effusion lymphoma (PEL) and multicentric Castleman disease (MCD). T cell immunity is vital for the control of KSHV infection and disease; however, few models of B lymphocyte infection exist to study immune recognition of such cells. Here, we developed a model of B lymphocyte infection with KSHV in which infected tonsillar B lymphocytes were expanded by providing mitogenic stimuli and then challenged with KSHV-specific CD4+ T cells. The infected cells expressed viral proteins found in PELs, namely, LANA and viral IRF3 (vIRF3), albeit at lower levels, with similar patterns of gene expression for the major latency, viral interleukin 6 (vIL-6), and vIRF3 transcripts. Despite low-level expression of open reading frame 50 (ORF50), transcripts for the immune evasion genes K3 and K5 were detected, with some downregulation of cell surface-expressed CD86 and ICAM. The vast majority of infected lymphocytes expressed IgM heavy chains with Igλ light chains, recapitulating the features seen in infected cells in MCD. We assessed the ability of the infected lymphocytes to be targeted by a panel of major histocompatibility complex (MHC) class II-matched CD4+ T cells and found that LANA-specific T cells restricted to different epitopes recognized these infected cells. Given that at least some KSHV latent antigens are thought to be poor targets for CD8+ T cells, we suggest that CD4+ T cells are potentially important effectors for the in vivo control of KSHV-infected B lymphocytes. IMPORTANCE KSHV establishes a latent reservoir within B lymphocytes, but few models exist to study KSHV-infected B cells other than the transformed PEL cell lines, which have likely accrued mutations during the transformation process. We developed a model of KSHV-infected primary B lymphocytes that

  4. Activation of Latent HIV Using Drug-loaded Nanoparticles

    NASA Astrophysics Data System (ADS)

    Kovochich, Michael

    Antiretroviral therapy is currently only capable of controlling human immunodeficiency virus (HIV) replication, rather than completely eradicating virus from patients. This is due in part to the establishment of a latent virus reservoir in resting CD4+ T-cells, which persists even in the presence of highly active antiretroviral therapy (HAART). It is thought that forced activation of latently infected cells could induce virus production, allowing targeting of the cell by the immune response. A variety of molecules are able to stimulate HIV from latency. However, no tested purging strategy has proven capable of eliminating the infection completely or preventing viral rebound if therapy is stopped. Hence, novel latency activation approaches are required. Nanoparticles can offer several advantages over more traditional drug delivery methods, including improved drug solubility, stability, and the ability to simultaneously target multiple different molecules to particular cell or tissue types. Here we describe the development of a novel lipid nanoparticle with the protein kinase C activator bryostatin-2 incorporated (LNP-Bry). These particles can target, activate primary human CD4+ T-cells, and stimulate latent virus production from human T-cell lines in vitro and from latently infected cells in a humanized mouse model ex vivo. This activation was synergistically enhanced by the histone deacetylase inhibitor (HDACi) sodium butyrate. Furthermore, LNP-Bry can also be loaded with the protease inhibitor nelfinavir (LNP-Bry-Nel), producing a particle capable of both activating latent virus and inhibiting viral spread. LNP-Bry was further tested for its in vivo biodistribution in both wild type mice (C57 black 6), as well as humanized mice (SCID-hu Thy/Liv, and bone marrow-liver-thymus [BLT]). LNP-Bry accumulated in the spleen and induced the early activation marker CD69 in wild type mice. Taken together, these data demonstrate the ability of nanotechnological approaches to

  5. Recombination enhances HIV-1 envelope diversity by facilitating the survival of latent genomic fragments in the plasma virus population

    SciTech Connect

    Immonen, Taina T.; Conway, Jessica M.; Romero-Severson, Ethan O.; Perelson, Alan S.; Leitner, Thomas; Kouyos, Roger Dimitri

    2015-12-22

    HIV-1 is subject to immune pressure exerted by the host, giving variants that escape the immune response an advantage. Virus released from activated latent cells competes against variants that have continually evolved and adapted to host immune pressure. Nevertheless, there is increasing evidence that virus displaying a signal of latency survives in patient plasma despite having reduced fitness due to long-term immune memory. We investigated the survival of virus with latent envelope genomic fragments by simulating within-host HIV-1 sequence evolution and the cycling of viral lineages in and out of the latent reservoir. Our model incorporates a detailed mutation process including nucleotide substitution, recombination, latent reservoir dynamics, diversifying selection pressure driven by the immune response, and purifying selection pressure asserted by deleterious mutations. We evaluated the ability of our model to capture sequence evolution in vivo by comparing our simulated sequences to HIV-1 envelope sequence data from 16 HIV-infected untreated patients. Empirical sequence divergence and diversity measures were qualitatively and quantitatively similar to those of our simulated HIV-1 populations, suggesting that our model invokes realistic trends of HIV-1 genetic evolution. Moreover, reconstructed phylogenies of simulated and patient HIV-1 populations showed similar topological structures. Our simulation results suggest that recombination is a key mechanism facilitating the persistence of virus with latent envelope genomic fragments in the productively infected cell population. Recombination increased the survival probability of latent virus forms approximately 13-fold. Prevalence of virus with latent fragments in productively infected cells was observed in only 2% of simulations when we ignored recombination, while the proportion increased to 27% of simulations when we allowed recombination. We also found that the selection pressures exerted by different fitness

  6. Recombination Enhances HIV-1 Envelope Diversity by Facilitating the Survival of Latent Genomic Fragments in the Plasma Virus Population

    PubMed Central

    Immonen, Taina T.; Conway, Jessica M.; Romero-Severson, Ethan O.; Perelson, Alan S.; Leitner, Thomas

    2015-01-01

    HIV-1 is subject to immune pressure exerted by the host, giving variants that escape the immune response an advantage. Virus released from activated latent cells competes against variants that have continually evolved and adapted to host immune pressure. Nevertheless, there is increasing evidence that virus displaying a signal of latency survives in patient plasma despite having reduced fitness due to long-term immune memory. We investigated the survival of virus with latent envelope genomic fragments by simulating within-host HIV-1 sequence evolution and the cycling of viral lineages in and out of the latent reservoir. Our model incorporates a detailed mutation process including nucleotide substitution, recombination, latent reservoir dynamics, diversifying selection pressure driven by the immune response, and purifying selection pressure asserted by deleterious mutations. We evaluated the ability of our model to capture sequence evolution in vivo by comparing our simulated sequences to HIV-1 envelope sequence data from 16 HIV-infected untreated patients. Empirical sequence divergence and diversity measures were qualitatively and quantitatively similar to those of our simulated HIV-1 populations, suggesting that our model invokes realistic trends of HIV-1 genetic evolution. Moreover, reconstructed phylogenies of simulated and patient HIV-1 populations showed similar topological structures. Our simulation results suggest that recombination is a key mechanism facilitating the persistence of virus with latent envelope genomic fragments in the productively infected cell population. Recombination increased the survival probability of latent virus forms approximately 13-fold. Prevalence of virus with latent fragments in productively infected cells was observed in only 2% of simulations when we ignored recombination, while the proportion increased to 27% of simulations when we allowed recombination. We also found that the selection pressures exerted by different fitness

  7. Evaluating Clonal Expansion of HIV-Infected Cells: Optimization of PCR Strategies to Predict Clonality

    PubMed Central

    Laskey, Sarah B.; Pohlmeyer, Christopher W.; Bruner, Katherine M.; Siliciano, Robert F.

    2016-01-01

    In HIV-infected individuals receiving suppressive antiretroviral therapy, the virus persists indefinitely in a reservoir of latently infected cells. The proliferation of these cells may contribute to the stability of the reservoir and thus to the lifelong persistence of HIV-1 in infected individuals. Because the HIV-1 replication process is highly error-prone, the detection of identical viral genomes in distinct host cells provides evidence for the clonal expansion of infected cells. We evaluated alignments of unique, near-full-length HIV-1 sequences to determine the relationship between clonality in a short region and clonality in the full genome. Although it is common to amplify and sequence short, subgenomic regions of the viral genome for phylogenetic analysis, we show that sequence identity of these amplicons does not guarantee clonality across the full viral genome. We show that although longer amplicons capture more diversity, no subgenomic region can recapitulate the diversity of full viral genomes. Consequently, some identical subgenomic amplicons should be expected even from the analysis of completely unique viral genomes, and the presence of identical amplicons alone is not proof of clonally expanded HIV-1. We present a method for evaluating evidence of clonal expansion in the context of these findings. PMID:27494508

  8. Evaluating Clonal Expansion of HIV-Infected Cells: Optimization of PCR Strategies to Predict Clonality.

    PubMed

    Laskey, Sarah B; Pohlmeyer, Christopher W; Bruner, Katherine M; Siliciano, Robert F

    2016-08-01

    In HIV-infected individuals receiving suppressive antiretroviral therapy, the virus persists indefinitely in a reservoir of latently infected cells. The proliferation of these cells may contribute to the stability of the reservoir and thus to the lifelong persistence of HIV-1 in infected individuals. Because the HIV-1 replication process is highly error-prone, the detection of identical viral genomes in distinct host cells provides evidence for the clonal expansion of infected cells. We evaluated alignments of unique, near-full-length HIV-1 sequences to determine the relationship between clonality in a short region and clonality in the full genome. Although it is common to amplify and sequence short, subgenomic regions of the viral genome for phylogenetic analysis, we show that sequence identity of these amplicons does not guarantee clonality across the full viral genome. We show that although longer amplicons capture more diversity, no subgenomic region can recapitulate the diversity of full viral genomes. Consequently, some identical subgenomic amplicons should be expected even from the analysis of completely unique viral genomes, and the presence of identical amplicons alone is not proof of clonally expanded HIV-1. We present a method for evaluating evidence of clonal expansion in the context of these findings. PMID:27494508

  9. Manifest and Latent Variates

    ERIC Educational Resources Information Center

    Maraun, Michael D.; Halpin, Peter F.

    2008-01-01

    The clue to what latent variable models are, and to a workable account of the basis for the traditional manifest/latent variable distinction, lies in a reconsideration of the indeterminacy property of linear factor structures. In this article, the authors contend that latent variable models are not detectors of unobservable latent structures,…

  10. Characterization of a spliced exon product of herpes simplex type-1 latency-associated transcript in productively infected cells

    SciTech Connect

    Kang, Wen; Mukerjee, Ruma; Gartner, Jared J.; Hatzigeorgiou, Artemis G.; Sandri-Goldin, Rozanne M.; Fraser, Nigel W. . E-mail: nfraser@mail.med.upenn.edu

    2006-12-20

    The latency-associated transcripts (LATs) of herpes simplex virus type-1 (HSV-1) are the only viral RNAs accumulating during latent infections in the sensory ganglia of the peripheral nervous system. The major form of LAT that accumulates in latently infected neurons is a 2 kb intron, spliced from a much less abundant 8.3 primary transcript. The spliced exon mRNA has been hard to detect. However, in this study, we have examined the spliced exon RNA in productively infected cells using ribonuclease protection (RPA), and quantitative RT-PCR (q-PCR) assays. We were able to detect the LAT exon RNA in productively infected SY5Y cells (a human neuronal cell line). The level of the LAT exon RNA was found to be approximately 5% that of the 2 kb intron RNA and thus is likely to be relatively unstable. Quantitative RT-PCR (q-PCR) assays were used to examine the LAT exon RNA and its properties. They confirmed that the LAT exon mRNA is present at a very low level in productively infected cells, compared to the levels of other viral transcripts. Furthermore, experiments showed that the LAT exon mRNA is expressed as a true late gene, and appears to be polyadenylated. In SY5Y cells, in contrast to most late viral transcripts, the LAT exon RNA was found to be mainly nuclear localized during the late stage of a productive infection. Interestingly, more LAT exon RNA was found in the cytoplasm in differentiated compared to undifferentiated SY5Y cells, suggesting the nucleocytoplasmic distribution of the LAT exon RNA and its related function may be influenced by the differentiation state of cells.

  11. BACTERIAL FOODBORNE INFECTIONS AFTER HEMATOPOIETIC CELL TRANSPLANTATION

    PubMed Central

    Boyle, Nicole; Podczervinski, Sara; Jordan, Kim; Stednick, Zach; Butler-Wu, Susan; McMillen, Kerry; Pergam, Steven A.

    2014-01-01

    Background Diarrhea, abdominal pain and fever are common among patients undergoing hematopoietic cell transplant (HCT), but such symptoms are also typical with foodborne infections. The burden of disease caused by foodborne infections in patients undergoing HCT is unknown. We sought to describe bacterial foodborne infection incidence post-transplant within a single-center population of HCT recipients. Methods All HCT recipients transplanted from 2001 through 2011 at the Fred Hutchinson Cancer Research Center in Seattle, WA were followed for one year post-transplant. Data were collected retrospectively using center databases, which include information from transplant, on-site examinations, outside records, and collected laboratory data. Patients were considered to have a bacterial foodborne infection if Campylobacter jejuni/coli, Listeria monocytogenes, E. coli 0157:H7, Salmonella species, Shigella species, Vibrio species or Yersinia species were isolated in culture within one-year post-transplant. Non-foodborne infections with these agents and patients with preexisting bacterial foodborne infection (within 30 days of transplant) were excluded from analyses. Results A total of 12/4069 (0.3%) patients developed a bacterial foodborne infection within one year post-transplant. Patients with infections had a median age at transplant of 50.5 years (interquartile range [IQR]: 35–57), and the majority were adults ≥18 years of age (9/12 [75%]), male gender (8/12 [67%]) and post-allogeneic transplant (8/12 [67%]). Infectious episodes occurred at an incidence rate of 1.0 per 100,000 patient-days (95% CI: 0.5–1.7) and at a median of 50.5 days after transplant (IQR: 26–58.5). The most frequent pathogen detected was Campylobacter jejuni/coli (5/12 [42%]) followed by Yersinia (3/12 [25%]), while Salmonella (2/12 [17%]) and Listeria (2/12 [17%]) showed equal frequencies; no cases of Shigella, Vibrio, or E. coli 0157:H7 were detected. Most patients were diagnosed via stool

  12. Purinergic signalling in a latent stem cell niche of the rat spinal cord.

    PubMed

    Marichal, Nicolás; Fabbiani, Gabriela; Trujillo-Cenóz, Omar; Russo, Raúl E

    2016-06-01

    The ependyma of the spinal cord harbours stem cells which are activated by traumatic spinal cord injury. Progenitor-like cells in the central canal (CC) are organized in spatial domains. The cells lining the lateral aspects combine characteristics of ependymocytes and radial glia (RG) whereas in the dorsal and ventral poles, CC-contacting cells have the morphological phenotype of RG and display complex electrophysiological phenotypes. The signals that may affect these progenitors are little understood. Because ATP is massively released after spinal cord injury, we hypothesized that purinergic signalling plays a part in this spinal stem cell niche. We combined immunohistochemistry, in vitro patch-clamp whole-cell recordings and Ca(2+) imaging to explore the effects of purinergic agonists on ependymal progenitor-like cells in the neonatal (P1-P6) rat spinal cord. Prolonged focal application of a high concentration of ATP (1 mM) induced a slow inward current. Equimolar concentrations of BzATP generated larger currents that reversed close to 0 mV, had a linear current-voltage relationship and were blocked by Brilliant Blue G, suggesting the presence of functional P2X7 receptors. Immunohistochemistry showed that P2X7 receptors were expressed around the CC and the processes of RG. BzATP also generated Ca(2+) waves in RG that were triggered by Ca(2+) influx and propagated via Ca(2+) release from internal stores through activation of ryanodine receptors. We speculate that the intracellular Ca(2+) signalling triggered by P2X7 receptor activation may be an epigenetic mechanism to modulate the behaviour of progenitors in response to ATP released after injury. PMID:26988236

  13. Performance of Interferon-Gamma and IP-10 Release Assays for Diagnosing Latent Tuberculosis Infections in Patients with Concurrent Malaria in Tanzania.

    PubMed

    Drabe, Camilla H; Vestergaard, Lasse S; Helleberg, Marie; Nyagonde, Nyagonde; Rose, Michala V; Francis, Filbert; Theilgaard, Ola P; Asbjørn, Jens; Amos, Ben; Bygbjerg, Ib Christian; Ruhwald, Morten; Ravn, Pernille

    2016-04-01

    Interferon-gamma (IFN-γ) release assays (IGRAs) are used to detect cellular immune recognition of Mycobacterium tuberculosis The chemokine IFN-γ-inducible protein 10 (IP-10) is an alternative diagnostic biomarker to IFN-γ. Several conditions interfere with IGRA test performance. We aimed to assess the possible influence of Plasmodium falciparum infection on the IGRA test QuantiFERON-TB GOLD® In-Tube (QFT) test and an in-house IP-10 release assay. In total, 241 Tanzanian adults were included; 184 patients with uncomplicated malaria (88 human immunodeficiency virus [HIV] coinfected) and 57 HIV-infected patients without malaria infection. Malaria was treated with artemether-lumefantrine (Coartem®). QFT testing was performed before initiation of malaria treatment and at days 7 and 42. In total, 172 patients completed follow-up. IFN-γ and IP-10 was measured in QFT supernatants. We found that during malaria infection IFN-γ and IP-10 levels in the unstimulated samples were elevated, mitogen responsiveness was impaired, and CD4 cell counts were decreased. These alterations reverted after malaria treatment. Concurrent malaria infection did not affect QFT test results, whereas there were more indeterminate IP-10 results during acute malaria infection. We suggest that IGRA and IP-10 release assay results of malaria patients should be interpreted with caution and that testing preferably should be postponed until after malaria treatment. PMID:26834199

  14. Eliminating the latent HIV reservoir by reactivation strategies

    PubMed Central

    Rasmussen, Thomas A.; Tolstrup, Martin; Winckelmann, Anni; Østergaard, Lars; Søgaard, Ole S.

    2013-01-01

    Combination antiretroviral therapy (cART) has transformed HIV from a deadly to a chronic disease, but HIV patients are still burdened with excess morbidity and mortality, long-term toxicities from cART, stigmatization, and insufficient access to cART worldwide. Thus, a cure for HIV would have enormous impact on society as well as the individual. As the complexity and mechanisms of HIV persistence during therapy are being unraveled, new therapeutic targets for HIV eradication are discovered. Substances that activate HIV production in the latently infected cells have recently received much attention. By turning on expression of latent HIV proviruses, reactivation strategies could contribute to the eradication HIV infection. Compounds that are currently being or soon to be tested in clinical trials are emphasized. The results from these trials will provide important clues as to whether or not reactivating strategies could become significant components of a cure for HIV. PMID:23563519

  15. Deconvolution of Ensemble Chromatin Interaction Data Reveals the Latent Mixing Structures in Cell Subpopulations.

    PubMed

    Sefer, Emre; Duggal, Geet; Kingsford, Carl

    2016-06-01

    Chromosome conformation capture (3C) experiments provide a window into the spatial packing of a genome in three dimensions within the cell. This structure has been shown to be correlated with gene regulation, cancer mutations, and other genomic functions. However, 3C provides mixed measurements on a population of typically millions of cells, each with a different genome structure due to the fluidity of the genome and differing cell states. Here, we present several algorithms to deconvolve these measured 3C matrices into estimations of the contact matrices for each subpopulation of cells and relative densities of each subpopulation. We formulate the problem as that of choosing matrices and densities that minimize the Frobenius distance between the observed 3C matrix and the weighted sum of the estimated subpopulation matrices. Results on HeLa 5C and mouse and bacteria Hi-C data demonstrate the methods' effectiveness. We also show that domain boundaries from deconvolved matrices are often more enriched or depleted for regulatory chromatin markers when compared to boundaries from convolved matrices. PMID:27267775

  16. HIV Eradication: Combinatorial Approaches to Activate Latent Viruses

    PubMed Central

    De Crignis, Elisa; Mahmoudi, Tokameh

    2014-01-01

    The concept of eradication of the Human Immune Deficiency Virus (HIV) from infected patients has gained much attention in the last few years. While combination Anti-Retroviral Therapy (c-ART) has been extremely effective in suppressing viral replication, it is not curative. This is due to the presence of a reservoir of latent HIV infected cells, which persist in the presence of c-ART. Recently, pharmaceutical approaches have focused on the development of molecules able to induce HIV-1 replication from latently infected cells in order to render them susceptible to viral cytopathic effects and host immune responses. Alternative pathways and transcription complexes function to regulate the activity of the HIV promoter and might serve as molecular targets for compounds to activate latent HIV. A combined therapy coupling various depressors and activators will likely be the most effective in promoting HIV replication while avoiding pleiotropic effects at the cellular level. Moreover, in light of differences among HIV subtypes and variability in integration sites, the combination of multiple agents targeting multiple pathways will increase likelihood of therapeutic effectiveness and prevent mutational escape. This review provides an overview of the mechanisms that can be targeted to induce HIV activation focusing on potential combinatorial approaches. PMID:25421889

  17. HIV eradication: combinatorial approaches to activate latent viruses.

    PubMed

    De Crignis, Elisa; Mahmoudi, Tokameh

    2014-11-01

    The concept of eradication of the Human Immune Deficiency Virus (HIV) from infected patients has gained much attention in the last few years. While combination Anti-Retroviral Therapy (c-ART) has been extremely effective in suppressing viral replication, it is not curative. This is due to the presence of a reservoir of latent HIV infected cells, which persist in the presence of c-ART. Recently, pharmaceutical approaches have focused on the development of molecules able to induce HIV-1 replication from latently infected cells in order to render them susceptible to viral cytopathic effects and host immune responses. Alternative pathways and transcription complexes function to regulate the activity of the HIV promoter and might serve as molecular targets for compounds to activate latent HIV. A combined therapy coupling various depressors and activators will likely be the most effective in promoting HIV replication while avoiding pleiotropic effects at the cellular level. Moreover, in light of differences among HIV subtypes and variability in integration sites, the combination of multiple agents targeting multiple pathways will increase likelihood of therapeutic effectiveness and prevent mutational escape. This review provides an overview of the mechanisms that can be targeted to induce HIV activation focusing on potential combinatorial approaches. PMID:25421889

  18. Attenuation of the type I interferon response in cells infected with human rhinovirus

    SciTech Connect

    Kotla, Swathi; Peng, Tao; Bumgarner, Roger E.; Gustin, Kurt E.

    2008-05-10

    The type I interferon (IFN) response requires the coordinated activation of the latent transcription factors NF-{kappa}B, IRF-3 and ATF-2 which in turn activate transcription from the IFN-{beta} promoter. Here we have examined the type I interferon response in rhinovirus type 14-infected A549 cells, with particular emphasis on the status of the transcription factor IRF-3. Our results indicate that although rhinovirus type 14 (RV14) infection induces the activation of NF-{kappa}B and ATF-2, only very low levels of IFN-{beta} mRNA are detected. Analysis of ISG54 mRNA levels revealed very little induction of this IRF-3 responsive transcript and suggested that IRF-3 activation might be impaired. Examination of IRF-3 in RV14-infected cells demonstrated only low levels of phosphorylation, a lack of homodimer formation and an absence of nuclear accumulation indicating that this transcription factor is not activated. Inhibition of viral protein synthesis following infection resulted in an increase in IFN-{beta} mRNA levels indicating that viral gene products prevent induction of this pathway. Collectively, these results indicate that RV14 infection inhibits the host type I interferon response by interfering with IRF-3 activation.

  19. Parasitic Infections in Hematopoietic Stem Cell Transplantation

    PubMed Central

    Jarque, Isidro; Salavert, Miguel; Pemán, Javier

    2016-01-01

    Parasitic infections are rarely documented in hematopoietic stem cell transplant recipients. However they may be responsible for fatal complications that are only diagnosed at autopsy. Increased awareness of the possibility of parasitic diseases both in autologous and allogeneic stem cell transplant patients is relevant not only for implementing preventive measures but also for performing an early diagnosis and starting appropriate therapy for these unrecognized but fatal infectious complications in hematopoietic transplant recipients. In this review, we will focus on parasitic diseases occurring in this population especially those with major clinical relevance including toxoplasmosis, American trypanosomiasis, leishmaniasis, malaria, and strongyloidiasis, among others, highlighting the diagnosis and management in hematopoietic transplant recipients. PMID:27413527

  20. Parasitic Infections in Hematopoietic Stem Cell Transplantation.

    PubMed

    Jarque, Isidro; Salavert, Miguel; Pemán, Javier

    2016-01-01

    Parasitic infections are rarely documented in hematopoietic stem cell transplant recipients. However they may be responsible for fatal complications that are only diagnosed at autopsy. Increased awareness of the possibility of parasitic diseases both in autologous and allogeneic stem cell transplant patients is relevant not only for implementing preventive measures but also for performing an early diagnosis and starting appropriate therapy for these unrecognized but fatal infectious complications in hematopoietic transplant recipients. In this review, we will focus on parasitic diseases occurring in this population especially those with major clinical relevance including toxoplasmosis, American trypanosomiasis, leishmaniasis, malaria, and strongyloidiasis, among others, highlighting the diagnosis and management in hematopoietic transplant recipients. PMID:27413527

  1. Hospital infection control in hematopoietic stem cell transplant recipients.

    PubMed Central

    Dykewicz, C. A.

    2001-01-01

    Guidelines for Preventing Opportunistic Infections Among Hematopoietic Stem Cell Transplant Recipients contains a section on hospital infection control including evidence-based recommendations regarding ventilation, construction, equipment, plants, play areas and toys, health-care workers, visitors, patient skin and oral care, catheter-related infections, drug-resistant organisms, and specific nosocomial infections. These guidelines are intended to reduce the number and severity of hospital infections in hematopoietic stem cell transplant recipients. PMID:11294720

  2. In vitro Inactivation of Latent HSV by Targeted Mutagenesis Using an HSV-specific Homing Endonuclease.

    PubMed

    Aubert, Martine; Boyle, Nicole M; Stone, Daniel; Stensland, Laurence; Huang, Meei-Li; Magaret, Amalia S; Galetto, Roman; Rawlings, David J; Scharenberg, Andrew M; Jerome, Keith R

    2014-01-01

    Following acute infection, herpes simplex virus (HSV) establishes latency in sensory neurons, from which it can reactivate and cause recurrent disease. Available antiviral therapies do not affect latent viral genomes; therefore, they do not prevent reactivation following therapy cessation. One possible curative approach involves the introduction of DNA double strand breaks in latent HSV genomes by rare-cutting endonucleases, leading to mutagenesis of essential viral genes. We tested this approach in an in vitro HSV latency model using the engineered homing endonuclease (HE) HSV1m5, which recognizes a sequence in the HSV-1 gene UL19, encoding the virion protein VP5. Coexpression of the 3'-exonuclease Trex2 with HEs increased HE-mediated mutagenesis frequencies up to sixfold. Following HSV1m5/Trex2 delivery with adeno-associated viral (AAV) vectors, the target site was mutated in latent HSV genomes with no detectable cell toxicity. Importantly, HSV production by latently infected cells after reactivation was decreased after HSV1m5/Trex2 exposure. Exposure to histone deacetylase inhibitors prior to HSV1m5/Trex2 treatment increased mutagenesis frequencies of latent HSV genomes another two- to fivefold, suggesting that chromatin modification may be a useful adjunct to gene-targeting approaches. These results support the continuing development of HEs and other nucleases (ZFNs, TALENs, CRISPRs) for cure of chronic viral infections.Molecular Therapy-Nucleic Acids (2014) 3, e1; doi:10.1038/mtna.2013.75; published online 4 February 2014. PMID:24496438

  3. In vitro Inactivation of Latent HSV by Targeted Mutagenesis Using an HSV-specific Homing Endonuclease

    PubMed Central

    Aubert, Martine; Boyle, Nicole M; Stone, Daniel; Stensland, Laurence; Huang, Meei-Li; Magaret, Amalia S; Galetto, Roman; Rawlings, David J; Scharenberg, Andrew M; Jerome, Keith R

    2014-01-01

    Following acute infection, herpes simplex virus (HSV) establishes latency in sensory neurons, from which it can reactivate and cause recurrent disease. Available antiviral therapies do not affect latent viral genomes; therefore, they do not prevent reactivation following therapy cessation. One possible curative approach involves the introduction of DNA double strand breaks in latent HSV genomes by rare-cutting endonucleases, leading to mutagenesis of essential viral genes. We tested this approach in an in vitro HSV latency model using the engineered homing endonuclease (HE) HSV1m5, which recognizes a sequence in the HSV-1 gene UL19, encoding the virion protein VP5. Coexpression of the 3′-exonuclease Trex2 with HEs increased HE-mediated mutagenesis frequencies up to sixfold. Following HSV1m5/Trex2 delivery with adeno-associated viral (AAV) vectors, the target site was mutated in latent HSV genomes with no detectable cell toxicity. Importantly, HSV production by latently infected cells after reactivation was decreased after HSV1m5/Trex2 exposure. Exposure to histone deacetylase inhibitors prior to HSV1m5/Trex2 treatment increased mutagenesis frequencies of latent HSV genomes another two- to fivefold, suggesting that chromatin modification may be a useful adjunct to gene-targeting approaches. These results support the continuing development of HEs and other nucleases (ZFNs, TALENs, CRISPRs) for cure of chronic viral infections. PMID:24496438

  4. Vaccinia Virus Recombinant Expressing Herpes Simplex Virus Type 1 Glycoprotein D Prevents Latent Herpes in Mice

    NASA Astrophysics Data System (ADS)

    Cremer, Kenneth J.; Mackett, Michael; Wohlenberg, Charles; Notkins, Abner Louis; Moss, Bernard

    1985-05-01

    In humans, herpes simplex virus causes a primary infection and then often a latent ganglionic infection that persists for life. Because these latent infections can recur periodically, vaccines are needed that can protect against both primary and latent herpes simplex infections. Infectious vaccinia virus recombinants that contain the herpes simplex virus type 1 (HSV-1) glycoprotein D gene under control of defined early or late vaccinia virus promoters were constructed. Tissue culture cells infected with these recombinant viruses synthesized a glycosylated protein that had the same mass (60,000 daltons) as the glycoprotein D produced by HSV-1. Immunization of mice with one of these recombinant viruses by intradermal, subcutaneous, or intraperitoneal routes resulted in the production of antibodies that neutralized HSV-1 and protected the mice against subsequent lethal challenge with HSV-1 or HSV-2. Immunization with the recombinant virus also protected the majority of the mice against the development of a latent HSV-1 infection of the trigeminal ganglia. This is the first demonstration that a genetically engineered vaccine can prevent the development of latency.

  5. Comparison of QuantiFERON-TB gold in tube test versus tuberculin skin test for screening of latent tuberculosis infection in Saudi Arabia: A population-based study

    PubMed Central

    Balkhy, Hanan H.; El Beltagy, Kamel; El-Saed, Aiman; Aljasir, Badr; Althaqafi, Abdulhakeem; Alothman, Adel F.; Alshalaan, Mohammad; Al-Jahdali, Hamdan

    2016-01-01

    OBJECTIVES: To compare QuantiFERON-TB gold in tube (QFT-GIT) test with tuberculin skin test (TST) in detecting latent tuberculosis infection (LTBI) among a general population in Saudi Arabia. METHODS: A population-based cross-sectional study was conducted between July 2010 and March 2013 among individuals randomly selected from the list of those receiving care at primary healthcare centers in three provinces of Saudi Arabia; Central, Western, and Eastern provinces. Those younger than 5 years, immunocompromised, had a current or previous history of active TB, LTBI, or who were receiving anti-TB medications were excluded. Informed consent was obtained before the study questionnaire was completed. Participants were then evaluated for LTBI using QFT-GIT test followed immediately by TST. RESULTS: Of the 1369 subjects included in the final analysis, QFT-GIT was positive in 124 (9.1%) and TST was positive in 127 (9.3%). Positive concordance was observed in 49 (3.6%) subjects while negative concordance was observed in 1167 (85.2%) subjects. The overall agreement between the two tests was 88.8% with a significant kappa (κ) test (κ = 0.332, P < 0.001). Concordance was significantly higher in younger age, female gender, single status, students, primary education, living in middle-sized families, and never smoked. CONCLUSIONS: The overall agreement of TST and QFT-GIT for the detection of LTBI among a Saudi general population was 88.8%. QFT-GIT is probably comparable to TST for detecting LTBI in an intermediate TB burden country with high at birth bacille calmette guerin vaccination coverage. Further prospective studies are needed to compare the ability of both tests to predict TB disease. PMID:27512509

  6. Timing of therapy for latent tuberculosis infection among immigrants presenting to a U.S. public health clinic: a retrospective study

    PubMed Central

    Page, Kathleen R; Manabe, Yukari C; Adelakun, Akintoye; Federline, Lynn; Cronin, Wendy; Campbell, James D; Dorman, Susan E

    2008-01-01

    Background In the U.S. more than half of incident tuberculosis (TB) cases occur in immigrants. Current guidelines recommend screening and treatment for latent TB infection (LTBI) within 5 years of arrival to the U.S. This study evaluates the timing of LTBI therapy among immigrants presenting for care to a public health TB clinic. Methods Retrospective chart review of patients prescribed LTBI treatment based on medical records from Prince Georges County Health Department. Results 1882 immigrants received LTBI therapy at Prince Georges County Health Department between 1999 and 2004. 417 of these patients were diagnosed with LTBI through contact investigations and were excluded from the analysis. Among the remaining 1465 individuals, median time from arrival to the U.S. until initiation of LTBI therapy was 5 months (range 0–42.4 years). 16% of all immigrants initiated therapy more than 5 years after arrival to the U.S. A logistic regression model using risks identified on univariate analysis revealed that referral for therapy by non-immigration proceedings was the strongest predictor of initiation of therapy more than 5 years after arrival to the U.S. Other factors associated with > 5 year U.S. residence prior to initiation of LTBI therapy included female gender (adjusted odds ratio (AOR) 1.8, 95% CI 1.2–2.6), age ≥ 35 (AOR = 4.1, 95% 2.5–6.6), and originating from Latin American and the Caribbean (AOR = 1.9, 95% CI 1.3–3.0). Conclusion Foreign-born individuals who are not referred for LTBI therapy through immigration proceedings are less likely to receive LTBI therapy within 5 years of arrival to the U.S. These data highlight the need to explore other mechanisms for timely LTBI screening beyond services provided by immigration. PMID:18474110

  7. Screening of latent tuberculosis infection by interferon-γ release assays in rheumatic patients: a systemic review and meta-analysis.

    PubMed

    Ruan, Qiaoling; Zhang, Shu; Ai, Jingwen; Shao, Lingyun; Zhang, Wenhong

    2016-02-01

    The aim of this study is to assess the diagnostic value of interferon-γ release assays (IGRAs) for latent tuberculosis infection (LTBI) in patients with rheumatic disease before receiving biologic agents. MEDLINE and EMBASE databases were used for searching studies concerning the evaluation on the performance of IGRAs [QuantiFERON-TB Gold (QFT-G), QuantiFERON-TB Gold In-Tube (QFT-GIT) and T-SPOT.TB] in rheumatic patients before biological therapy. After assessing the quality of all studies included in the review, we summarized the results in subgroups using forest plots and calculated pooled estimates if applicable. The search identified 11 studies with a total sample size of 1940 individuals. Compared with the tuberculin skin test (TST), the pooled agreements in QFT-G/GIT and T-SPOT.TB were 72 % (95 % confidence interval (CI) 65, 78 %) and 75 % (95 % CI 67, 83 %), respectively. BCG vaccination was positively correlated with positive rates of TST (pooled odds ratio (OR) 1.64, 95 % CI 1.06, 2.53). Compared with TST, IGRAs were better associated with the presentence of one or more tuberculosis (TB) risk factors. Neither steroid nor disease-modifying anti-rheumatic drugs (DMARDs) significantly affect positive IGRA results. In contrast, TST positivity was significantly impacted by the use of steroid (pooled OR 0.45, 95 % CI 0.30, 0.69), but less significantly by the use of DMARDs (pooled OR 0.78, 95 % CI 0.50, 1.21). In conclusion, in rheumatic patients with previous BCG vaccination or currently on steroid therapy, IGRAs would be the better choice to identify LTBI by decreasing the false-positivity and false-negativity rate compared with conventional TST. PMID:25376466

  8. Comparison study of QuantiFERON test with tuberculin skin testing to diagnose latent tuberculosis infection among nurses working in teaching hospitals of Ahvaz, Iran.

    PubMed Central

    Salmanzadeh, Shokrollah; Abbasissifar, Hajar; Alavi, Seyed Mohmmad

    2016-01-01

    Background: Prompt diagnosis and treatment of latent tuberculosis (TB) infection (LTBI) are needed to control TB. The aim of the study was to compare the performance of Quanti FERON-TB test (QFT) with conventional TST for the diagnosis of LTBI. Methods: In this analytical - comparison study, we enrolled 87 nurses working in teaching hospitals in Ahvaz. All study subjects were tested by TST. TST results were interpreted as positive if induration was more than 10 mm. If the level of QFT after stimulation was equal or greater than 0.35 IU/ml, test was considered as positive. Data were analyzed with SPSS program. QFT results compared with induration in TST and its relation to all variables were investigated. Results: The rate of LTB diagnosis by TST and QFT was 31% and 35.6%, respectively. There was no significant difference between TST and QFT in LTB diagnosis (P=0.62). Among the 56 subjects who were TST- negative, 14 cases (approximately 25%) were QFT- positive and 42 (75%) were QFT- negative. Among the 31 cases (35.6%) that had TST- positive, 13 (42%) were QFT-positive and 18 (58%) were QFT- negative. The overall percent agreement was 63.2% (k=0.139, P=0.69), discordance %=15.9-20.7, sensitivity= 41.5% and specificity=75.5%. Conclusion: Diagnostic value of QFT is similar to TST, when there is strong clinical and epidemiological evidence of LTB in a nurse with negative TST, adding QFT to diagnostic evaluation is associated with increased rate of LTB diagnosis.

  9. Mast cells expedite control of pulmonary murine cytomegalovirus infection by enhancing the recruitment of protective CD8 T cells to the lungs.

    PubMed

    Ebert, Stefan; Becker, Marc; Lemmermann, Niels A W; Büttner, Julia K; Michel, Anastasija; Taube, Christian; Podlech, Jürgen; Böhm, Verena; Freitag, Kirsten; Thomas, Doris; Holtappels, Rafaela; Reddehase, Matthias J; Stassen, Michael

    2014-04-01

    The lungs are a noted predilection site of acute, latent, and reactivated cytomegalovirus (CMV) infections. Interstitial pneumonia is the most dreaded manifestation of CMV disease in the immunocompromised host, whereas in the immunocompetent host lung-infiltrating CD8 T cells confine the infection in nodular inflammatory foci and prevent viral pathology. By using murine CMV infection as a model, we provide evidence for a critical role of mast cells (MC) in the recruitment of protective CD8 T cells to the lungs. Systemic infection triggered degranulation selectively in infected MC. The viral activation of MC was associated with a wave of CC chemokine ligand 5 (CCL5) in the serum of C57BL/6 mice that was MC-derived as verified by infection of MC-deficient Kit(W-sh/W-sh) "sash" mutants. In these mutants, CD8 T cells were recruited less efficiently to the lungs, correlating with enhanced viral replication and delayed virus clearance. A causative role for MC was verified by MC reconstitution of "sash" mice restoring both, efficient CD8 T-cell recruitment and infection control. These results reveal a novel crosstalk axis between innate and adaptive immune defense against CMV, and identify MC as a hitherto unconsidered player in the immune surveillance at a relevant site of CMV disease. PMID:24763809

  10. Rampant infections of bone marrow stem cell niches as triggers for spondyloarthropathies and rheumatoid arthritis.

    PubMed

    Berthelot, Jean-Marie; Sibilia, Jean

    2016-01-01

    Tropheryma Whipplei can induce rheumatism mimicking SpA or RA, but even more rampant bacterial/viral infections in epiphyseal bones could also contribute to the onset of RA and SpA. Indeed, as bone marrow stem cell niches are enriched in Tregs and myeloid derived suppressor cells, these areas are favourable for the persistence of quiescent viruses and/or dormant bacteria. This review focuses on the possibility that such silent infections of bone marrow stem cell niches might contribute to the pathogenesis of SpA and RA, at least during their onset. Some infections can affect the bone marrow mesenchymal stem cells, which can transmit these pathogens to their progeny. Transient but repeated revivals of viruses or dormant bacteria could promote the conversion of marrow regulatory T cells into effector phenotypes, leading to autoimmunity in the epiphyseal bone marrow, entheses and adjacent synovium. This scenario would also fit the flares of rheumatic disorders and explain why some joints or enthuses can be severely involved whereas their neighbours remain intact. The efficiency of anti-TNF drugs does not rule out a role of persistent infections in SpA and RA. These drugs do not affect chlamydial clearance, or the reactivation of latent Salmonella enterica serovar Typhimurium in mice or Epstein-Barr virus in humans. Anti-TNF might even prevent, rather than foster, the revival of dormant bacteria and viruses in marrow stem cell niches. Indeed, anti-TNF enhance the maturation of the immunosuppressive immature myeloid cells around stem cells into dendritic cells and macrophages, thus restoring immune responses in these areas. PMID:26886813

  11. The Significance of Sensitive Interferon Gamma Release Assays for Diagnosis of Latent Tuberculosis Infection in Patients Receiving Tumor Necrosis Factor-α Antagonist Therapy

    PubMed Central

    Jung, Yu Jung; Woo, Hye In; Jeon, Kyeongman; Koh, Won-Jung; Jang, Dong Kyoung; Cha, Hoon Suk; Koh, Eun Mi; Lee, Nam Yong; Kang, Eun-Suk

    2015-01-01

    Objective We compared two interferon gamma release assays (IGRAs), QuantiFERON-TB Gold In-Tube (QFT-GIT) and T-SPOT.TB, for diagnosis of latent tuberculosis infection (LTBI) in patients before and while receiving tumor necrosis factor (TNF)-α antagonist therapy. This study evaluated the significance of sensitive IGRAs for LTBI screening and monitoring. Methods Before starting TNF-α antagonist therapy, 156 consecutive patients with rheumatic diseases were screened for LTBI using QFT-GIT and T-SPOT.TB tests. According to our study protocol, QFT-GIT-positive patients received LTBI treatment. Patients positive by any IGRAs were subjected to follow-up IGRA tests after completing LTBI-treatment and/or during TNF-α antagonist therapy. Results At the initial LTBI screening, 45 (28.9%) and 70 (44.9%) patients were positive by QFT-GIT and T-SPOT.TB, respectively. The agreement rate between IGRA results was 78.8% (k = 0.56; 95% confidence interval [95% CI] = 0.43 to 0.68). Of 29 patients who were positive only by T-SPOT.TB in the initial screening, 83% (19/23) were persistently positive by T-SPOT.TB, while QFT-GIT testing showed that 36% (9/25) had conversion during TNF-α antagonist therapy. By the end of the follow-up period (218 to 1,264 days), four patients (4/137, 2.9%) developed active tuberculosis (TB) diseases during receiving TNF-α antagonist therapy. Among them, one was Q-T+, one was Q+T-, and the remaining two were Q-T- at the initial screening (Q, QuantiFERON-TB Gold In-Tube; T, T-SPOT.TB; +, positive; -, negative). Two (2/4, 50%) patients with TB reactivation had at least one prior risk factor consistent with previous TB infection. Conclusion This study demonstrated the need to capitalize on sensitive IGRAs to monitor for LTBI in at-risk patients for a more sensitive diagnosis in countries with an intermediate TB burden. PMID:26474294

  12. The interplay between human herpes simplex virus infection and the apoptosis and necroptosis cell death pathways.

    PubMed

    Yu, Xiaoliang; He, Sudan

    2016-01-01

    Human herpes simplex virus (HSV) is a ubiquitous human pathogen that establishes a lifelong latent infection and is associated with mucocutaneous lesions. In multicellular organisms, cell death is a crucial host defense mechanism that eliminates pathogen-infected cells. Apoptosis is a well-defined form of programmed cell death executed by a group of cysteine proteases, called caspases. Studies have shown that HSV has evolved strategies to counteract caspase activation and apoptosis by encoding anti-apoptotic viral proteins such as gD, gJ, Us3, LAT, and the ribonucleotide reductase large subunit (R1). Recently, necroptosis has been identified as a regulated form of necrosis that can be invoked in the absence of caspase activity. Receptor-interacting kinase 3 (RIP3 or RIPK3) has emerged as a central signaling molecule in necroptosis; it is activated via interaction with other RIP homotypic interaction motif (RHIM)-containing proteins such as RIP1 (or RIPK1). There is increasing evidence that HSV R1 manipulates necroptosis via the RHIM-dependent inactivation or activation ofRIP3 in a species-specific manner. This review summarizes the current understanding of the interplay between HSV infection and cell death pathways, with an emphasis on apoptosis and necroptosis. PMID:27154074

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

    PubMed Central

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

    2016-01-01

    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

  14. Macrophage cell death upon intracellular bacterial infection

    PubMed Central

    Lai, Xin-He; Xu, Yunsheng; Chen, Xiao-Ming; Ren, Yi

    2015-01-01

    Macrophage-pathogen interaction is a complex process and the outcome of this tag-of-war for both sides is to live or die. Without attempting to be comprehensive, this review will discuss the complexity and significance of the interaction outcomes between macrophages and some facultative intracellular bacterial pathogens as exemplified by Francisella, Salmonella, Shigella and Yersinia. Upon bacterial infection, macrophages can die by a variety of ways, such as apoptosis, autophagic cell death, necrosis, necroptosis, oncosis, pyronecrosis, pyroptosis etc, which is the focus of this review. PMID:26690967

  15. Ethanol stimulation of HIV infection of oral epithelial cells.

    PubMed

    Zheng, Jun; Yang, Otto O; Xie, Yiming; Campbell, Richard; Chen, Irvin S Y; Pang, Shen

    2004-12-01

    Oral mucosal cells can be infected by exogenous HIV during receptive oral sex or breast-feeding. The risk of oral mucosal infection depends on the infection efficiency of the HIV strains present in the oral cavity, the viral titers, and the defense mechanisms in the oral cavity environment. It is expected that alcohol can weaken the host defense mechanism against HIV infection in the oral cavity. We modified an HIV strain, NL4-3, by inserting the enhanced green fluorescent protein gene and used this virus to infect oral epithelial cells obtained from patients. Various concentrations of ethanol (0%-4%) were added to the infected cells. HIV-infected cells were detected by fluorescent microscopy or fluorescence-activated cell sorting. We found that ethanol significantly increases HIV infection of primary oral epithelial cells (POEs). POEs pretreated with 4% ethanol for less than 10 minutes demonstrated 3- to 6-fold higher susceptibility to infection by the CXCR-4 HIV strain NL4-3. Our studies also demonstrated that HIV infects POEs through a gp120-independent mechanism. We tested an HIV CCR5 strain, JRCSF, and also found its infection efficiency to be stimulated by alcohol. Our results indicate that in cell culture conditions, the ranges of concentrations of alcohol that are commercially available are able to stimulate the infection efficiency of HIV in POEs. PMID:15602121

  16. Extracellular Hsp90 serves as a co-factor for MAPK activation and latent viral gene expression during de novo infection by KSHV

    SciTech Connect

    Qin Zhiqiang; DeFee, Michael; Isaacs, Jennifer S.; Parsons, Chris

    2010-07-20

    The Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma (KS), an important cause of morbidity and mortality in immunocompromised patients. KSHV interaction with the cell membrane triggers activation of specific intracellular signal transduction pathways to facilitate virus entry, nuclear trafficking, and ultimately viral oncogene expression. Extracellular heat shock protein 90 localizes to the cell surface (csHsp90) and facilitates signal transduction in cancer cell lines, but whether csHsp90 assists in the coordination of KSHV gene expression through these or other mechanisms is unknown. Using a recently characterized non-permeable inhibitor specifically targeting csHsp90 and Hsp90-specific antibodies, we show that csHsp90 inhibition suppresses KSHV gene expression during de novo infection, and that this effect is mediated largely through the inhibition of mitogen-activated protein kinase (MAPK) activation by KSHV. Moreover, we show that targeting csHsp90 reduces constitutive MAPK expression and the release of infectious viral particles by patient-derived, KSHV-infected primary effusion lymphoma cells. These data suggest that csHsp90 serves as an important co-factor for KSHV-initiated MAPK activation and provide proof-of-concept for the potential benefit of targeting csHsp90 for the treatment or prevention of KSHV-associated illnesses.

  17. Extracellular Hsp90 serves as a co-factor for MAPK activation and latent viral gene expression during de novo infection by KSHV

    PubMed Central

    Qin, Zhiqiang; DeFee, Michael; Isaacs, Jennifer; Parsons, Chris

    2010-01-01

    The Kaposi’s sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi’s sarcoma (KS), an important cause of morbidity and mortality in immunocompromised patients. KSHV interaction with the cell membrane triggers activation of specific intracellular signal transduction pathways to facilitate virus entry, nuclear trafficking, and ultimately viral oncogene expression. Extracellular heat shock protein 90 localizes to the cell surface (csHsp90) and facilitates signal transduction in cancer cell lines, but whether csHsp90 assists in the coordination of KSHV gene expression through these or other mechanisms is unknown. Using a recently characterized non-permeable inhibitor specifically targeting csHsp90, we show that csHsp90 inhibition suppresses KSHV gene expression during de novo infection, and that this effect is mediated largely through the inhibition of mitogen-activated protein kinase (MAPK) activation by KSHV. Moreover, we show that targeting csHsp90 reduces constitutive MAPK expression and the release of infectious viral particles by patient-derived, KSHV-infected primary effusion lymphoma cells. These data suggest that csHsp90 serves as an important co-factor for KSHV-initiated MAPK activation and provide proof-of-concept for the potential benefit of targeting csHsp90 for the treatment or prevention of KSHV-associated illnesses. PMID:20451233

  18. Infection of vascular endothelial cells with herpes simplex virus enhances tissue factor activity and reduces thrombomodulin expression.

    PubMed Central

    Key, N S; Vercellotti, G M; Winkelmann, J C; Moldow, C F; Goodman, J L; Esmon, N L; Esmon, C T; Jacob, H S

    1990-01-01

    Latent infection of vascular cells with herpes-viruses may play a pathogenic role in the development of human atherosclerosis. In a previous study, we found that cultured human umbilical vein endothelial cells (HUVECs) infected with herpes simplex virus 1 (HSV-1) became procoagulant, exemplified both by their enhanced assembly of the prothrombinase complex and by their inability to reduce adhesion of platelets. We now report two further procoagulant consequences of endothelial HSV infection: loss of surface thrombomodulin (TM) activity and induction of synthesis of tissue factor. Within 4 hr of infection of HUVECs, TM activity measured by thrombin-dependent protein C activation declined 21 +/- 3% (P less than 0.05) and by 18 hr, 48 +/- 5% (P less than 0.001). Similar significant TM decrements accompanied infection of bovine aortic endothelial cells. Identical TM loss was induced with HSV-2 infection but not with adenovirus infection. Decreased surface expression of TM antigen (measured by the specific binding of a polyclonal antibody to bovine TM) closely paralleled the loss of TM activity. As examined by Northern blotting, these losses apparently reflected rapid onset (within 4 hr of HSV infection) loss of mRNA for TM. In contrast, HSV infection induced a viral-dose-dependent increase in synthesis of tissue factor protein, adding to the procoagulant state. The results indicate that loss of endothelial protein-synthetic capacity is not a universal effect of HSV infection. We suggest that the procoagulant state induced by reduction in TM activity and amplified tissue factor activity accompanying HSV infection of endothelium could contribute to deposition of thrombi on atherosclerotic plaques and to the "coagulant-necrosis" state that characterizes HSV-infected mucocutaneous lesions. Images PMID:2169619

  19. Cells infected with herpes simplex virus 1 export to uninfected cells exosomes containing STING, viral mRNAs, and microRNAs

    PubMed Central

    Kalamvoki, Maria; Du, Te; Roizman, Bernard

    2014-01-01

    STING (stimulator of IFN genes) activates the IFN-dependent innate immune response to infection on sensing the presence of DNA in cytosol. The quantity of STING accumulating in cultured cells varies; it is relatively high in some cell lines [e.g., HEp-2, human embryonic lung fibroblasts (HEL), and HeLa] and low in others (e.g., Vero cells). In a preceding publication we reported that STING was stable in four cell lines infected with herpes simplex virus 1 and that it was actively stabilized in at least two cell lines derived from human cancers. In this report we show that STING is exported from HEp-2 cells to Vero cells along with virions, viral mRNAs, microRNAs, and the exosome marker protein CD9. The virions and exosomes copurified. The quantity of STING and CD9 exported from one cell line to another was inoculum-size–dependent and reflected the levels of STING and CD9 accumulating in the cells in which the virus inoculum was made. The export of STING, an innate immune sensor, and of viral mRNAs whose major role may be in silencing viral genes in latently infected neurons, suggests that the virus has evolved mechanisms that curtail rather than foster the spread of infection under certain conditions. PMID:25368198

  20. Tissue myeloid cells in SIV-infected primates acquire viral DNA through phagocytosis of infected T cells.

    PubMed

    Calantone, Nina; Wu, Fan; Klase, Zachary; Deleage, Claire; Perkins, Molly; Matsuda, Kenta; Thompson, Elizabeth A; Ortiz, Alexandra M; Vinton, Carol L; Ourmanov, Ilnour; Loré, Karin; Douek, Daniel C; Estes, Jacob D; Hirsch, Vanessa M; Brenchley, Jason M

    2014-09-18

    The viral accessory protein Vpx, expressed by certain simian and human immunodeficiency viruses (SIVs and HIVs), is thought to improve viral infectivity of myeloid cells. We infected 35 Asian macaques and African green monkeys with viruses that do or do not express Vpx and examined viral targeting of cells in vivo. While lack of Vpx expression affected viral dynamics in vivo, with decreased viral loads and infection of CD4⁺ T cells, Vpx expression had no detectable effect on infectivity of myeloid cells. Moreover, viral DNA was observed only within myeloid cells in tissues not massively depleted of CD4⁺ T cells. Myeloid cells containing viral DNA also showed evidence of T cell phagocytosis in vivo, suggesting that their viral DNA may be attributed to phagocytosis of SIV-infected T cells. These data suggest that myeloid cells are not a major source of SIV in vivo, irrespective of Vpx expression. PMID:25238099

  1. Roles of the ITAM and PY motifs of Epstein-Barr virus latent membrane protein 2A in the inhibition of epithelial cell differentiation and activation of {beta}-catenin signaling.

    PubMed

    Morrison, Jennifer A; Raab-Traub, Nancy

    2005-02-01

    Epstein-Barr virus (EBV) latent membrane protein 2A (LMP2A) is important for maintenance of latency in infected B lymphocytes. Through its immunoreceptor tyrosine-based activation motif (ITAM) and PY motifs, LMP2A is able to block B-cell receptor (BCR) signaling, bind BCR-associated kinases, and manipulate the turnover of itself and these kinases via a PY-mediated interaction with the Nedd4 family of ubiquitin ligases. In epithelial cells, LMP2A has been shown to activate the phosphatidylinositol 3'-OH kinase/Akt and beta-catenin signaling pathways. In the present study, the biological consequences of LMP2A expression in the normal human foreskin keratinocyte (HFK) cell line were investigated and the importance of the ITAM and PY motifs for LMP2A signaling effects in HFK cells was ascertained. The ITAM was essential for the activation of Akt by LMP2A in HFK cells, while both the ITAM and PY motifs contributed to LMP2A-mediated accumulation and nuclear translocation of the oncoprotein beta-catenin. LMP2A inhibited induction of differentiation in an assay conducted with semisolid methylcellulose medium, and the PY motifs were critical for this inhibition. LMP2A is expressed in the EBV-associated epithelial malignancies nasopharyngeal carcinoma and gastric carcinoma, and these data indicate that LMP2A affects cellular processes that likely contribute to carcinogenesis. PMID:15681438

  2. Generalized Latent Trait Models.

    ERIC Educational Resources Information Center

    Moustaki, Irini; Knott, Martin

    2000-01-01

    Discusses a general model framework within which manifest variables with different distributions in the exponential family can be analyzed with a latent trait model. Presents a unified maximum likelihood method for estimating the parameters of the generalized latent trait model and discusses the scoring of individuals on the latent dimensions.…

  3. Infected cell protein 0 functional domains and their coordination in herpes simplex virus replication.

    PubMed

    Gu, Haidong

    2016-02-12

    Herpes simplex virus 1 (HSV-1) is a ubiquitous human pathogen that establishes latent infection in ganglia neurons. Its unique life cycle requires a balanced "conquer and compromise" strategy to deal with the host anti-viral defenses. One of HSV-1 α (immediate early) gene products, infected cell protein 0 (ICP0), is a multifunctional protein that interacts with and modulates a wide range of cellular defensive pathways. These pathways may locate in different cell compartments, which then migrate or exchange factors upon stimulation, for the purpose of a concerted and effective defense. ICP0 is able to simultaneously attack multiple host pathways by either degrading key restrictive factors or modifying repressive complexes. This is a viral protein that contains an E3 ubiquitin ligase, translocates among different cell compartments and interacts with major defensive complexes. The multiple functional domains of ICP0 can work independently and at the same time coordinate with each other. Dissecting the functional domains of ICP0 and delineating the coordination of these domains will help us understand HSV-1 pathogenicity as well as host defense mechanisms. This article focuses on describing individual ICP0 domains, their biochemical properties and their implication in HSV-1 infection. By putting individual domain functions back into the picture of host anti-viral defense network, this review seeks to elaborate the complex interactions between HSV-1 and its host. PMID:26870669

  4. Infected cell protein 0 functional domains and their coordination in herpes simplex virus replication

    PubMed Central

    Gu, Haidong

    2016-01-01

    Herpes simplex virus 1 (HSV-1) is a ubiquitous human pathogen that establishes latent infection in ganglia neurons. Its unique life cycle requires a balanced “conquer and compromise” strategy to deal with the host anti-viral defenses. One of HSV-1 α (immediate early) gene products, infected cell protein 0 (ICP0), is a multifunctional protein that interacts with and modulates a wide range of cellular defensive pathways. These pathways may locate in different cell compartments, which then migrate or exchange factors upon stimulation, for the purpose of a concerted and effective defense. ICP0 is able to simultaneously attack multiple host pathways by either degrading key restrictive factors or modifying repressive complexes. This is a viral protein that contains an E3 ubiquitin ligase, translocates among different cell compartments and interacts with major defensive complexes. The multiple functional domains of ICP0 can work independently and at the same time coordinate with each other. Dissecting the functional domains of ICP0 and delineating the coordination of these domains will help us understand HSV-1 pathogenicity as well as host defense mechanisms. This article focuses on describing individual ICP0 domains, their biochemical properties and their implication in HSV-1 infection. By putting individual domain functions back into the picture of host anti-viral defense network, this review seeks to elaborate the complex interactions between HSV-1 and its host. PMID:26870669

  5. High-Throughput Single-Cell Kinetics of Virus Infections in the Presence of Defective Interfering Particles

    PubMed Central

    Akpinar, Fulya; Timm, Andrea

    2015-01-01

    ABSTRACT Defective interfering particles (DIPs) are virus mutants that lack essential genes for growth. In coinfections with helper virus, the diversion of viral proteins to the replication and packaging of DIP genomes can interfere with virus production. Mounting cases of DIPs and DIP-like genomes in clinical and natural isolates, as well as growing interest in DIP-based therapies, underscore a need to better elucidate how DIPs work. DIP activity is primarily measured by its inhibition of virus infection yield, an endpoint that masks the dynamic and potentially diverse individual cell behaviors. Using vesicular stomatitis virus (VSV) as a model, we coinfected BHK cells with VSV DIPs and recombinant helper virus carrying a gene encoding a red fluorescent protein (RFP) whose expression correlates with the timing and level of virus release. For single cells within a monolayer, 10 DIPs per cell suppressed the reporter expression in only 1.2% of the cells. In most cells, it slowed and reduced viral gene expression, manifested as a shift in mean latent time from 4 to 6 h and reduced virus yields by 10-fold. For single cells isolated in microwells, DIP effects were more pronounced, reducing virus yields by 100-fold and extending latent times to 12 h, including individual instances above 20 h. Together, these results suggest that direct or indirect cell-cell interactions prevent most coinfected cells from being completely suppressed by DIPs. Finally, a gamma distribution model captures well how the infection kinetics quantitatively depends on the DIP dose. Such models will be useful for advancing a predictive biology of DIP-associated virus growth and infection spread. IMPORTANCE During the last century, basic studies in virology have focused on developing a molecular mechanistic understanding of how infectious viruses reproduce in their living host cells. However, over the last 10 years, the advent of deep sequencing and other powerful technologies has revealed in

  6. Isolation of virus from brain after immunosuppression of mice with latent herpes simplex

    NASA Astrophysics Data System (ADS)

    Kastrukoff, Lorne; Long, Carol; Doherty, Peter C.; Wroblewska, Zofia; Koprowski, Hilary

    1981-06-01

    Herpes simplex virus (HSV) is usually present in a latent form in the trigeminal ganglion of man1-3. Various stress factors may induce virus reactivation, which is manifest by a lip lesion (innervated from the trigeminal ganglion) and the production of infectious virus. The considerable experimental efforts to define the conditions that lead to the reactivation of latent HSV have concentrated on isolating virus either from the original extraneural site of virus inoculation, or from cell-free homogenates of sensory ganglia from latently infected animals4-15. Recent DNA hybridization experiments resulted in the demonstration of the presence of HSV genomes in the brain tissue of both latently infected mice, and of humans who showed no clinical symptoms of HSV (ref. 16 and N. Fraser, personal communication). This led us to consider the possibility that HSV may be present in brain tissue as the result of either reactivation of the virus in brain cells or the passage of reactivated virus from trigeminal ganglia through the brain stem to the brain. The presence of infectious HSV in brain tissue has not previously been demonstrated; yet this could be a factor in chronic, relapsing neurological diseases such as multiple sclerosis. We have now shown experimentally that mice carrying latent HSV in their trigeminal ganglia may, following massive immunosuppression, express infectious virus in the central nervous system (CNS).

  7. The effect of HIV coinfection, HAART and TB treatment on cytokine/chemokine responses to Mycobacterium tuberculosis (Mtb) antigens in active TB patients and latently Mtb infected individuals.

    PubMed

    Kassa, Desta; de Jager, Wilco; Gebremichael, Gebremedhin; Alemayehu, Yodit; Ran, Leonie; Fransen, Justin; Wolday, Dawit; Messele, Tsehaynesh; Tegbaru, Belete; Ottenhoff, Tom H M; van Baarle, Debbie

    2016-01-01

    Identification of Mtb specific induced cytokine/chemokine host biomarkers could assist in developing novel diagnostic, prognostic and therapeutic tools for TB. Levels of IFN-γ, IL-2, IL-17, IL-10, IP-10 and MIP-1α were measured in supernatants of whole blood stimulated with Mtb specific fusion protein ESAT-6/CFP-10 using xMAP technology. The study groups were HIV positive TB patients (HIV(+)TB(+)), HIV negative TB patients (HIV(-)TB(+)), HIV positive tuberculin skin test positive (TST+) (HIV(+)TST(+)), HIV negative TST+ (HIV(-)TST(+)), and HIV(-)TST(-) individuals. Compared to HIV(-)TST(-), latent TB infection led to increased levels of IP-10, IFN-γ and IL-17, while levels of IL-2 and IP-10 were increased with active TB. Levels of IFN-γ, IL-17, MIP-1α, and IL-10 were increased in HIV(-)TST(+) individuals compared to HIV(-)TB(+) patients. HIV coinfection decreased the level of IFN-γ, IL-17, IP-10 and IL-2. After six months (M6) of anti-TB treatment (ATT) in HIV(-)TB(+) patients, IFN-γ, IL-10, and MIP-1α levels normalized. After M6 and M18 of ATT plus HAART in HIV(+)TB(+) patients, levels of MIP-1α and IL-10 normalized, while this was not the case for IFN-γ, IL-2, IL-17, and IP-10 levels. In HIV(+)TST(+) patients on HAART, levels of IFN-γ, IL-17, IL-10 and MIP-1α normalized, while no change in the levels of IL-2 and IP-10 were observed. In conclusion, the simultaneous measurement of IFN-γ, IL-17 and IP-10 may assist in diagnosing LTBI; IL-2 and IP-10 may assist in diagnosing active TB; while IFN-γ, IL-17, MIP-1α, and IL-10 levels could help to discriminate LTBI and active TB. In addition, IL-10 and MIP-1α levels could help to monitor responses to TB treatment and HAART. PMID:26631832

  8. Comparison of Interferon-γ Release Assay to Two Cut-Off Points of Tuberculin Skin Test to Detect Latent Mycobacterium tuberculosis Infection in Primary Health Care Workers

    PubMed Central

    de Souza, Fernanda Mattos; do Prado, Thiago Nascimento; Pinheiro, Jair dos Santos; Peres, Renata Lyrio; Lacerda, Thamy Carvalho; Loureiro, Rafaela Borge; Carvalho, Jose Américo; Fregona, Geisa; Dias, Elias Santos; Cosme, Lorrayne Beliqui; Rodrigues, Rodrigo Ribeiro; Riley, Lee Wood; Maciel, Ethel Leonor Noia

    2014-01-01

    Background An interferon-γ release assay, QuantiFERON-TB (QFT) test, has been introduced an alternative test for the diagnosis of latent Mycobacterium tuberculosis infection (LTBI). Here, we compared the performance of QFT with tuberculin skin test (TST) measured at two different cut-off points among primary health care work (HCW) in Brazil. Methods A cross-sectional study was carried out among HCWs in four Brazilian cities with a known history of high incidence of TB. Results of the QFT were compared to TST results based on both ≥5 mm and ≥10 mm as cut-off points. Results We enrolled 632 HCWs. When the cut-off value of ≥10 mm was used, agreement between QFT and TST was 69% (k = 0.31), and when the cut-off of ≥5 mm was chosen, the agreement was 57% (k = 0.22). We investigated possible factors of discordance of TST vs QFT. Compared to the TST−/QFT− group, risk factors for discordance in the TST+/QFT− group with TST cut-off of ≥5 mm included age between 41–45 years [OR = 2.70; CI 95%: 1.32–5.51] and 46–64 years [OR = 2.04; CI 95%: 1.05–3.93], BCG scar [OR = 2.72; CI 95%: 1.40–5.25], and having worked only in primary health care [OR = 2.30; CI 95%: 1.09–4.86]. On the other hand, for the cut-off of ≥10 mm, BCG scar [OR = 2.26; CI 95%: 1.03–4.91], being a household contact of a TB patient [OR = 1.72; CI 95%: 1.01–2.92] and having had a previous TST [OR = 1.66; CI 95%: 1.05–2.62], were significantly associated with the TST+/QFT− group. No statistically significant associations were found among the TST−/QFT+ discordant group with either TST cut-off value. Conclusions Although we identified BCG vaccination to contribute to the discordance at both TST cut-off measures, the current Brazilian recommendation for the initiation of LTBI treatment, based on information gathered from medical history, TST, chest radiograph and physical examination, should not be changed. PMID:25137040

  9. Latent Tuberculosis Infection Diagnostic and Treatment Cascade among Contacts in Primary Health Care in a City of Sao Paulo State, Brazil: Cross-Sectional Study

    PubMed Central

    2016-01-01

    Background Diagnosis and treatment of latent tuberculosis infection (LTBI) is a tool for global TB control, especially in close contacts. But data is scarce in high burden countries, under field conditions, including data on the benefits of LTBI management. Objective To analyze the LTBI diagnosis and treatment cascade among contacts in primary health care (PHC) services in São José do Rio Preto—SP, Brazil. Methods Cross-sectional design, conducted with contacts of pulmonary TB patients followed in all PHC services. Data was collected from May to September 2014 in the Reporting System for TB cases (TBWEB) and Reporting System for Chemoprophylaxis. Medical records and treatment follow-up forms were reviewed and all the nurses responsible for TB in PHC services were interviewed. Results Among 336 contacts included, 267 (79.4%) were screened for TB or LTBI, according to the presence or not of respiratory symptoms. Among those contacts screened, 140 (52.4%) were symptomatic, 9 (3.4%) had TB disease, 106/221 (48%) had positive TST result, meeting the criteria for LTBI treatment, and 64/106 (60.4%) actually started it. Overall, among 267 screened, only 64 (24%) started LTBI treatment. The completion rates of treatment among the contacts who started it, those with positive TST result and those screened were 56.3% (36/64), 16.3% (36/221) and 13.5% (36/267), respectively. Nurses claimed that asymptomatic TB contacts pay no attention to preventive health care and do not seek medical care as they do not have symptoms of the disease. In reviewing the medical records, high proportions of contacts without evaluation, incomplete assessment, incorrect records of contraindication for LTBI treatment, lack of notes regarding the identification and evaluation of contacts were identified. Conclusions There is a need for better organization of the surveillance and investigation routine for contacts in PHC, considering the reorganization of the work process and the features of the

  10. Latent tuberculosis infection, tuberculin skin test and vitamin D status in contacts of tuberculosis patients: a cross-sectional and case-control study

    PubMed Central

    2011-01-01

    Background Deficient serum vitamin D levels have been associated with incidence of tuberculosis (TB), and latent tuberculosis infection (LTBI). However, to our knowledge, no studies on vitamin D status and tuberculin skin test (TST) conversion have been published to date. The aim of this study was to estimate the associations of serum 25-hydroxyvitamin D3 (25[OH]D) status with LTBI prevalence and TST conversion in contacts of active TB in Castellon (Spain). Methods The study was designed in two phases: cross-sectional and case-control. From November 2009 to October 2010, contacts of 42 TB patients (36 pulmonary, and 6 extra-pulmonary) were studied in order to screen for TB. LTBI and TST conversion cases were defined following TST, clinical, analytic and radiographic examinations. Serum 25(OH)D levels were measured by electrochemiluminescence immunoassay (ECLIA) on a COBAS® 410 ROCHE® analyzer. Logistic regression models were used in the statistical analysis. Results The study comprised 202 people with a participation rate of 60.1%. Only 20.3% of the participants had a sufficient serum 25(OH)D (≥ 30 ng/ml) level. In the cross-sectional phase, 50 participants had LTBI and no association between LTBI status and serum 25(OH)D was found. After 2 months, 11 out of 93 negative LTBI participants, without primary prophylaxis, presented TST conversion with initial serum 25(OH)D levels: a:19.4% (7/36): < 20 ng/ml, b:12.5% (4/32):20-29 ng/ml, and c:0%(0/25) ≥ 30 ng/ml. A sufficient serum 25(OH)D level was a protector against TST conversion a: Odds Ratio (OR) = 1.00; b: OR = 0.49 (95% confidence interval (CI) 0.07-2.66); and c: OR = 0.10 (95% CI 0.00-0.76), trends p = 0.019, adjusted for high exposure and sputum acid-fast bacilli positive index cases. The mean of serum level 25(OH)D in TST conversion cases was lower than controls,17.5 ± 5.6 ng/ml versus 25.9 ± 13.7 ng/ml (p = 0.041). Conclusions The results suggest that sufficient serum 25(OH)D levels protect against

  11. Combined Expression of IFN-γ, IL-17, and IL-4 mRNA by Recall PBMCs Moderately Discriminates Active Tuberculosis from Latent Mycobacterium tuberculosis Infection in Patients with Miscellaneous Inflammatory Underlying Conditions.

    PubMed

    Savolainen, Laura E; Kantele, Anu; Knuuttila, Aija; Pusa, Liana; Karttunen, Riitta; Valleala, Heikki; Tuuminen, Tamara

    2016-01-01

    New biomarkers are needed for discriminating active tuberculosis (TB) from latent TB infection (LTBI), especially in vulnerable groups representing the major diagnostic challenge. This pilot study was carried out to explore the diagnostic potential of selected genes, IFN-γ, IL-17, IL-4, and FoxP3, associated with TB immunity and immunopathology. IFN-γ, IL-17, IL-4, and FoxP3 mRNA expression levels were measured by quantitative reverse transcription PCR (RT-qPCR) from antigen-stimulated peripheral blood mononuclear cells of patients with active TB (n = 25); patients with miscellaneous inflammatory disorders and concomitant LTBI (n = 20), rheumatoid arthritis (RA) being the most predominant in the group (n = 11); and in healthy Bacillus Calmette-Guérin (BCG) vaccinees (n = 8). While the levels of FoxP3 mRNA did not differ between the tested groups, the cumulative expression levels of purified protein derivative-stimulated IFN-γ, IL-17, and IL-4 mRNAs were found to distinguish active TB from the whole group of LTBI with 48% sensitivity and 85% specificity. When restricting the LTBI group to RA cases only, the sensitivity was 56% and specificity 100%. When interpreting the result as positive in at least one of the mRNAs IFN-γ, IL-17, or IL-4, sensitivity of 64% and specificities of 75% (heterogeneous group of LTBI) or 100% (LTBI with RA) were achieved. Moderate discrimination of active TB from LTBI with miscellaneous inflammatory underlying conditions by using combined quantitative expression of IFN-γ, IL-17, and IL-4 mRNA seems not to be of high diagnostic potential. PMID:27379100

  12. Combined Expression of IFN-γ, IL-17, and IL-4 mRNA by Recall PBMCs Moderately Discriminates Active Tuberculosis from Latent Mycobacterium tuberculosis Infection in Patients with Miscellaneous Inflammatory Underlying Conditions

    PubMed Central

    Savolainen, Laura E.; Kantele, Anu; Knuuttila, Aija; Pusa, Liana; Karttunen, Riitta; Valleala, Heikki; Tuuminen, Tamara

    2016-01-01

    New biomarkers are needed for discriminating active tuberculosis (TB) from latent TB infection (LTBI), especially in vulnerable groups representing the major diagnostic challenge. This pilot study was carried out to explore the diagnostic potential of selected genes, IFN-γ, IL-17, IL-4, and FoxP3, associated with TB immunity and immunopathology. IFN-γ, IL-17, IL-4, and FoxP3 mRNA expression levels were measured by quantitative reverse transcription PCR (RT-qPCR) from antigen-stimulated peripheral blood mononuclear cells of patients with active TB (n = 25); patients with miscellaneous inflammatory disorders and concomitant LTBI (n = 20), rheumatoid arthritis (RA) being the most predominant in the group (n = 11); and in healthy Bacillus Calmette–Guérin (BCG) vaccinees (n = 8). While the levels of FoxP3 mRNA did not differ between the tested groups, the cumulative expression levels of purified protein derivative-stimulated IFN-γ, IL-17, and IL-4 mRNAs were found to distinguish active TB from the whole group of LTBI with 48% sensitivity and 85% specificity. When restricting the LTBI group to RA cases only, the sensitivity was 56% and specificity 100%. When interpreting the result as positive in at least one of the mRNAs IFN-γ, IL-17, or IL-4, sensitivity of 64% and specificities of 75% (heterogeneous group of LTBI) or 100% (LTBI with RA) were achieved. Moderate discrimination of active TB from LTBI with miscellaneous inflammatory underlying conditions by using combined quantitative expression of IFN-γ, IL-17, and IL-4 mRNA seems not to be of high diagnostic potential. PMID:27379100

  13. Senescence affects endothelial cells susceptibility to dengue virus infection.

    PubMed

    AbuBakar, Sazaly; Shu, Meng-Hooi; Johari, Jefree; Wong, Pooi-Fong

    2014-01-01

    Alteration in the endothelium leading to increased vascular permeability contributes to plasma leakage seen in dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). An earlier study showed that senescent endothelial cells (ECs) altered the ECs permeability. Here we investigated the susceptibility of senescing human umbilical vein endothelial cells (HUVECs) to dengue virus infection and determined if dengue virus infection induces HUVECs senescence. Our results suggest that DENV type-2 (DENV-2) foci forming unit (FFU) and extracellular virus RNA copy number were reduced by at least 35% and 85% in infection of the intermediate young and early senescent HUVECs, respectively, in comparison to infection of young HUVECs. No to low infectivity was recovered from infection of late senescent HUVECs. DENV infection also increases the percentage of HUVECs expressing senescence-associated (SA)-β-gal, cells arrested at the G2/M phase or 4N DNA content stage and cells with enlarged morphology, indicative of senescing cells. Alteration of HUVECs morphology was recorded using impedance-based real-time cell analysis system following DENV-2 infection. These results suggest that senescing HUVECs do not support DENV infection and DENV infection induces HUVECs senescence. The finding highlights the possible role of induction of senescence in DENV infection of the endothelial cells. PMID:24782642

  14. [Is it possible to cure HIV infection?].

    PubMed

    Gutiérrez, Carolina; Madrid, Nadia P; Moreno, Santiago

    2015-09-01

    Antiretroviral therapy has significantly improved the life expectancy in HIV-infected people, but it cannot cure the disease by itself. Several barriers have been identified for the cure of HIV infection, including a reservoir of latently infected cells, persistent viral replication in tissues, and anatomical sanctuaries. The main strategy proposed for the cure of HIV consists on the administration of drugs that, through the reactivation of latent HIV, would eliminate the cell reservoir. Ongoing clinical trials have shown the proof of concept, but the efficacy of these drugs in decreasing the reservoir size has not been proved so far. PMID:26365737

  15. Combined Analysis of IFN-γ, IL-2, IL-5, IL-10, IL-1RA and MCP-1 in QFT Supernatant Is Useful for Distinguishing Active Tuberculosis from Latent Infection.

    PubMed

    Suzukawa, Maho; Akashi, Shunsuke; Nagai, Hideaki; Nagase, Hiroyuki; Nakamura, Hiroyuki; Matsui, Hirotoshi; Hebisawa, Akira; Ohta, Ken

    2016-01-01

    The QuantiFERON®-TB Gold In-Tube test (QFT), an interferon-γ release assay, is used to diagnose Mycobacterium tuberculosis, but its inaccuracy in distinguishing active tuberculosis from latent infection is a major concern. There is thus a need for an easy and accurate tool for achieving that goal in daily clinical settings. This study aimed to identify candidate cytokines for specifically differentiating active tuberculosis from latent infection. Our study population consisted of 31 active TB (tuberculosis) patients, 29 LTBI (latent tuberculosis infection) patients and 10 healthy control subjects. We assayed for 27 cytokines in QFT supernatants of both specific antigen-stimulated blood samples (TBAg) and negative-control samples (Nil). We analyzed their specificities and sensitivities by creating receiver operating characteristic (ROC) curves and measuring the area under those curves (AUCs). In TBAg-Nil supernatants, IL-10, IFN-γ, MCP-1 and IL-1RA showed high AUCs of 0.8120, 0.7842, 0.7419 and 0.7375, respectively. Compared with each cytokine alone, combined assay for these top four cytokines showed positive rates in diagnosing active TB, and GDA analysis revealed that MCP-1 and IL-5 are potent in distinguishing active TB from LTBI, with Wilk's lambda = 0.718 (p < 0.001). Furthermore, utilizing the unique characteristic of IL-2 that its TBAg-Nil supernatant levels are higher in LTBI compared to active TB, the difference between IFN-γ and IL-2 showed a large AUC of 0.8910. In summary, besides IFN-γ, IL-2, IL-5, IL-10, IL-1RA and MCP-1 in QFT supernatants may be useful for distinguishing active TB from LTBI. Those cytokines may also help us understand the difference in pathogenesis between active TB and LTBI. PMID:27035669

  16. Combined Analysis of IFN-γ, IL-2, IL-5, IL-10, IL-1RA and MCP-1 in QFT Supernatant Is Useful for Distinguishing Active Tuberculosis from Latent Infection

    PubMed Central

    Suzukawa, Maho; Akashi, Shunsuke; Nagai, Hideaki; Nagase, Hiroyuki; Nakamura, Hiroyuki; Matsui, Hirotoshi; Hebisawa, Akira; Ohta, Ken

    2016-01-01

    The QuantiFERON®-TB Gold In-Tube test (QFT), an interferon-γ release assay, is used to diagnose Mycobacterium tuberculosis, but its inaccuracy in distinguishing active tuberculosis from latent infection is a major concern. There is thus a need for an easy and accurate tool for achieving that goal in daily clinical settings. This study aimed to identify candidate cytokines for specifically differentiating active tuberculosis from latent infection. Our study population consisted of 31 active TB (tuberculosis) patients, 29 LTBI (latent tuberculosis infection) patients and 10 healthy control subjects. We assayed for 27 cytokines in QFT supernatants of both specific antigen-stimulated blood samples (TBAg) and negative-control samples (Nil). We analyzed their specificities and sensitivities by creating receiver operating characteristic (ROC) curves and measuring the area under those curves (AUCs). In TBAg–Nil supernatants, IL-10, IFN-γ, MCP-1 and IL-1RA showed high AUCs of 0.8120, 0.7842, 0.7419 and 0.7375, respectively. Compared with each cytokine alone, combined assay for these top four cytokines showed positive rates in diagnosing active TB, and GDA analysis revealed that MCP-1 and IL-5 are potent in distinguishing active TB from LTBI, with Wilk’s lambda = 0.718 (p < 0.001). Furthermore, utilizing the unique characteristic of IL-2 that its TBAg–Nil supernatant levels are higher in LTBI compared to active TB, the difference between IFN-γ and IL-2 showed a large AUC of 0.8910. In summary, besides IFN-γ, IL-2, IL-5, IL-10, IL-1RA and MCP-1 in QFT supernatants may be useful for distinguishing active TB from LTBI. Those cytokines may also help us understand the difference in pathogenesis between active TB and LTBI. PMID:27035669

  17. Erbb2 DNA vaccine combined with regulatory T cell deletion enhances antibody response and reveals latent low-avidity T cells: potential and limits of its therapeutic efficacy.

    PubMed

    Rolla, Simona; Ria, Francesco; Occhipinti, Sergio; Di Sante, Gabriele; Iezzi, Manuela; Spadaro, Michela; Nicolò, Chiara; Ambrosino, Elena; Merighi, Irene Fiore; Musiani, Piero; Forni, Guido; Cavallo, Federica

    2010-06-01

    Rat (r)Erbb2 transgenic BALB-neuT mice genetically predestined to develop multiple invasive carcinomas allow an assessment of the potential of a vaccine against the stages of cancer progression. Because of rErbb2 expression in the thymus and its overexpression in the mammary gland, CD8(+) T cell clones reacting at high avidity with dominant rErbb2 epitopes are deleted in these mice. In BALB-neuT mice with diffuse and invasive in situ lesions and almost palpable carcinomas, a temporary regulatory T cells depletion combined with anti-rErbb2 vaccine markedly enhanced the anti-rErbb2 Ab response and allowed the expansion of latent pools of low-avidity CD8(+) T cells bearing TCRs repertoire reacting with the rErbb2 dominant peptide. This combination of a higher Ab response and activation of a low-avidity cytotoxic response persistently blocked tumor progression at stages in which the vaccine alone was ineffective. However, when diffuse and invasive microscopic cancers become almost palpable, this combination was no longer able to secure a significant extension of mice survival. PMID:20435927

  18. Microfold Cells Actively Translocate Mycobacterium tuberculosis to Initiate Infection.

    PubMed

    Nair, Vidhya R; Franco, Luis H; Zacharia, Vineetha M; Khan, Haaris S; Stamm, Chelsea E; You, Wu; Marciano, Denise K; Yagita, Hideo; Levine, Beth; Shiloh, Michael U

    2016-08-01

    The prevailing paradigm is that tuberculosis infection is initiated when patrolling alveolar macrophages and dendritic cells within the terminal alveolus ingest inhaled Mycobacterium tuberculosis (Mtb). However, definitive data for this model are lacking. Among the epithelial cells of the upper airway, a specialized epithelial cell known as a microfold cell (M cell) overlies various components of mucosa-associated lymphatic tissue. Here, using multiple mouse models, we show that Mtb invades via M cells to initiate infection. Intranasal Mtb infection in mice lacking M cells either genetically or by antibody depletion resulted in reduced invasion and dissemination to draining lymph nodes. M cell-depleted mice infected via aerosol also had delayed dissemination to lymph nodes and reduced mortality. Translocation of Mtb across two M cell transwell models was rapid and transcellular. Thus, M cell translocation is a vital entry mechanism that contributes to the pathogenesis of Mtb. PMID:27452467

  19. Polypeptide synthesis in alphavirus-infected Aedes albopictus cells during the establishment of persistent infection.

    PubMed

    Richardson, M A; Boulton, R W; Raghow, R S; Dalgarno, L

    1980-01-01

    Polypeptide synthesis was examined in mosquito cells during the establishment of a persistent infection with two alphaviruses, Ross River virus (RRV) and Semliki Forest virus (SFV), and in vertebrate cells cytopathically-infected with the same viruses. In Aedes albopictus cell, RRV reached peak titres at 34--48 hours p.i. At 12 hours 85 per cent of cells assayed as infected by infective centre assay; by 48 hours when persistence was established, virus production was reduced and less than 5 per cent of cells assayed as infected. There was no shut-down of host polypeptide synthesis during infection. Viral polypeptide synthesis was maximal between 10 and 24 hours p.i. The major viral polypeptides labelled were nucleocapsid protein and envelope protein(s). The precursor polypeptide p95 which was prominent in infected BHK cells was not detected in mosquito cells. Similar results were obtained on SFV infection. During the establishment of persistence there was a coordinate decline in the synthesis of RRV polypeptides, reaching undetectable levels by 72 hours p.i. Subculturing persitently-infected cells led to a small increase in viral polypeptide synthesis and virus titre. In contrast, during RRV growth in BHK celos host protein synthesis was severly inhibited and by 9--11 hours p.i. virus-specific polypeptide synthesis represented more than 90 per cent of total protein synthetic activity. PMID:7356398

  20. Prokineticins and Merkel cell polyomavirus infection in Merkel cell carcinoma

    PubMed Central

    Lauttia, S; Sihto, H; Kavola, H; Koljonen, V; Böhling, T; Joensuu, H

    2014-01-01

    Background: Prokineticin-1 (PROK1) and prokineticin-2 (PROK2) are chemokine-like proteins that may influence cancer growth by regulating host defence and angiogenesis. Their significance in viral infection-associated cancer is incompletely understood. We studied prokineticins in Merkel cell carcinoma (MCC), a skin cancer linked with Merkel cell polyomavirus (MCPyV) infection. Methods: Carcinoma cell expression of PROK1 and PROK2 and their receptors (PROKR1 and PROKR2) was investigated with immunohistochemistry, and tumour PROK1 and PROK2 mRNA content with quantitative PCR from 98 MCCs. Subsets of tumour infiltrating leukocytes were identified using immunohistochemistry. Results: Merkel cell polyomavirus-positive MCCs had higher than the median PROK2 mRNA content, whereas MCPyV-negative MCCs contained frequently PROK1 mRNA. Cancers with high tumour PROK2 mRNA content had high counts of tumour infiltrating macrophages (CD68+ and CD163+ cells). Patients with higher than the median PROK2 mRNA content had 44.9% 5-year survival compared with 23.5% among those with a smaller content (hazard ratio (HR): 0.53; 95% confidence interval (CI): 0.34–0.84; P=0.005), whereas the presence of PROK1 mRNA in tumour was associated with unfavourable survival (P=0.052). Conclusions: The results suggest that prokineticins are associated with MCPyV infection and participate in regulation of the immune response in MCC, and may influence outcome of MCC patients. PMID:24496457

  1. Maintenance of Large Numbers of Virus Genomes in Human Cytomegalovirus-Infected T98G Glioblastoma Cells

    PubMed Central

    Duan, Ying-Liang; Ye, Han-Qing; Zavala, Anamaria G.; Yang, Cui-Qing; Miao, Ling-Feng; Fu, Bi-Shi; Seo, Keun Seok; Davrinche, Christian

    2014-01-01

    ABSTRACT After infection, human cytomegalovirus (HCMV) persists for life. Primary infections and reactivation of latent virus can both result in congenital infection, a leading cause of central nervous system birth defects. We previously reported long-term HCMV infection in the T98G glioblastoma cell line (1). HCMV infection has been further characterized in T98Gs, emphasizing the presence of HCMV DNA over an extended time frame. T98Gs were infected with either HCMV Towne or AD169-IE2-enhanced green fluorescent protein (eGFP) strains. Towne infections yielded mixed IE1 antigen-positive and -negative (Ag+/Ag−) populations. AD169-IE2-eGFP infections also yielded mixed populations, which were sorted to obtain an IE2− (Ag−) population. Viral gene expression over the course of infection was determined by immunofluorescent analysis (IFA) and reverse transcription-PCR (RT-PCR). The presence of HCMV genomes was determined by PCR, nested PCR (n-PCR), and fluorescence in situ hybridization (FISH). Compared to the HCMV latency model, THP-1, Towne-infected T98Gs expressed IE1 and latency-associated transcripts for longer periods, contained many more HCMV genomes during early passages, and carried genomes for a greatly extended period of passaging. Large numbers of HCMV genomes were also found in purified Ag− AD169-infected cells for the first several passages. Interestingly, latency transcripts were observed from very early times in the Towne-infected cells, even when IE1 was expressed at low levels. Although AD169-infected Ag− cells expressed no detectable levels of either IE1 or latency transcripts, they also maintained large numbers of genomes within the cell nuclei for several passages. These results identify HCMV-infected T98Gs as an attractive new model in the study of the long-term maintenance of virus genomes in the context of neural cell types. IMPORTANCE Our previous work showed that T98G glioblastoma cells were semipermissive to HCMV infection; virus

  2. Epstein-Barr Virus (EBV) Latent Membrane Protein-1 Down-Regulates Tumor Necrosis Factor-α (TNF-α) Receptor-1 and Confers Resistance to TNF-α-Induced Apoptosis in T Cells

    PubMed Central

    Chuang, Huai-Chia; Lay, Jong-Ding; Chuang, Shuang-En; Hsieh, Wen-Chuan; Chang, Yao; Su, Ih-Jen

    2007-01-01

    The infection of T cells by Epstein-Barr virus (EBV) may result in hemophagocytic syndrome (HPS) through enhanced cytokine secretion, particularly tumor necrosis factor-α (TNF-α), by EBV latent membrane protein-1 (LMP-1). One bewildering observation of HPS patients is relapsing disease or progression to T-cell lymphoma. This finding raises the question whether EBV LMP-1-expressing T cells may survive and proliferate in the cytokine milieu of HPS. To explore this possibility, we tested the sensitivity of LMP-1-expressing T cells to apoptosis in the presence of TNF-α. LMP-1 up-regulated TNF-α through TRAF2,5 and nuclear factor-κB pathway in T cells. The LMP-1-expressing T cells then became resistant to TNF-α-induced apoptosis. Interestingly, the expression of TNFR1 was remarkably down-regulated by LMP-1 in T cells. Furthermore, the TNF-α/TNFR1 downstream death signal TNFR1-associated death domain protein was constitutively recruited by LMP-1, and the activities of apoptotic caspases 3, 8, and 9 were suppressed. Reconstitution of TNFR1 successfully reversed the TNF-α-induced apoptotic cascades. Therefore, EBV LMP-1 not only activates T cells to proliferate but also confers resistance to TNF-α-mediated apoptosis via down-regulation of TNFR1 in the cytokine milieu of HPS. This finding provides a potential mechanism to explain the disease persistence or progression to T-cell lymphoma in HPS patients. PMID:17456766

  3. Acute Morphine Administration Reduces Cell-Mediated Immunity and Induces Reactivation of Latent Herpes Simplex Virus Type 1 in BALB/c Mice

    PubMed Central

    Mojadadi, Shafi; Jamali, Abbas; Khansarinejad, Behzad; Soleimanjahi, Hoorieh; Bamdad, Taravat

    2009-01-01

    Acute morphine administration is known to alter the course of herpes simplex virus infection. In this study, the effect of acute morphine administration on the reactivation of latent herpes was investigated in a mouse model. Because of the important role of cytolytic T lymphocyte (CTL) activity in the inhibition of herpes simplex virus type 1 (HSV-1) reactivation, the effect of acute morphine administration on CTL responses was also evaluated. Furthermore, lymphocyte proliferation and IFN-γ production were evaluated for their roles in the induction of the CTL response. The findings showed that acute morphine administration significantly reduced CTL responses, lymphocyte proliferation, and IFN-γ production. Furthermore, acute morphine administration has been shown to reactivate latent HSV-1. Previous studies have shown that cellular immune responses have important roles in the inhibition of HSV reactivation. These findings suggest that suppression of a portion of the cellular immune response after acute morphine administration may constitute one part of the mechanism that induces HSV reactivation. PMID:19403060

  4. Permissiveness of human hepatoma cell lines for HCV infection

    PubMed Central

    2012-01-01

    Background Although primary and established human hepatoma cell lines have been evaluated for hepatitis C virus (HCV) infection in vitro, thus far only Huh7 cells have been found to be highly permissive for infectious HCV. Since our understanding of the HCV lifecycle would benefit from the identification of additional permissive cell lines, we assembled a panel of hepatic and non-hepatic cell lines and assessed their ability to support HCV infection. Here we show infection of the human hepatoma cell lines PLC/PRF/5 and Hep3B with cell culture-derived HCV (HCVcc), albeit to lower levels than that achieved in Huh7 cells. To better understand the reduced permissiveness of PLC and Hep3B cells for HCVcc infection, we performed studies to evaluate the ability of each cell line to support specific steps of the viral lifecycle (i.e. entry, replication, egress and spread). Results We found that while the early events in HCV infection (i.e. entry plus replication initiation) are cumulatively equivalent or only marginally reduced in PLC and Hep3B cells, later steps of the viral life cycle such as steady-state replication, de novo virus production and/or spread are impaired to different degrees in PLC and Hep3B cultures compared to Huh7 cell cultures. Interestingly, we also observed that interferon stimulated gene (i.e. ISG56) expression was significantly and differentially up-regulated in PLC and Hep3B cells following viral infection. Conclusions We conclude that the restrictions observed later during HCV infection in these cell lines could in part be attributed to HCV-induced innate signaling. Nevertheless, the identification of two new cell lines capable of supporting authentic HCVcc infection, even at reduced levels, expands the current repertoire of cell lines amendable for the study of HCV in vitro and should aid in further elucidating HCV biology and the cellular determinants that modulate HCV infection. PMID:22273112

  5. Host-Cell Survival and Death During Chlamydia Infection

    PubMed Central

    Ying, Songmin; Pettengill, Matthew; Ojcius, David M.; Häcker, Georg

    2008-01-01

    Different Chlamydia trachomatis strains are responsible for prevalent bacterial sexually-transmitted disease and represent the leading cause of preventable blindness worldwide. Factors that predispose individuals to disease and mechanisms by which chlamydiae cause inflammation and tissue damage remain unclear. Results from recent studies indicate that prolonged survival and subsequent death of infected cells and their effect on immune effector cells during chlamydial infection may be important in determining the outcome. Survival of infected cells is favored at early times of infection through inhibition of the mitochondrial pathway of apoptosis. Death at later times displays features of both apoptosis and necrosis, but pro-apoptotic caspases are not involved. Most studies on chlamydial modulation of host-cell death until now have been performed in cell lines. The consequences for pathogenesis and the immune response will require animal models of chlamydial infection, preferably mice with targeted deletions of genes that play a role in cell survival and death. PMID:18843378

  6. Dendritic cells in progression and pathology of HIV infection

    PubMed Central

    Manches, Olivier; Frleta, Davor; Bhardwaj, Nina

    2014-01-01

    Although the major targets of HIV infection are CD4+ T cells, dendritic cells (DC) represent a crucial subset in HIV infection as they influence viral transmission, target cell infection and antigen presentation of HIV antigens. DC are potent antigen presenting cells that can modulate anti-viral immune responses. Through secretion of inflammatory cytokines and interferons (IFN), DC also alter T cell proliferation and differentiation, participating in the immune dysregulation characteristic of chronic HIV infection. Their wide distribution in close proximity with the mucosal epithelia makes them one of the first cell types to encounter HIV during sexual transmission [1]. We will discuss here the multiple roles that DC play at different stages of HIV infection, emphasizing their relevance to HIV pathology and progression. PMID:24246474

  7. TIM3 Mediates T Cell Exhaustion during Mycobacterium tuberculosis Infection

    PubMed Central

    Jayaraman, Pushpa; Jacques, Miye K.; Zhu, Chen; Steblenko, Katherine M.; Stowell, Britni L.; Madi, Asaf; Anderson, Ana C.; Kuchroo, Vijay K.; Behar, Samuel M.

    2016-01-01

    While T cell immunity initially limits Mycobacterium tuberculosis infection, why T cell immunity fails to sterilize the infection and allows recrudescence is not clear. One hypothesis is that T cell exhaustion impairs immunity and is detrimental to the outcome of M. tuberculosis infection. Here we provide functional evidence for the development T cell exhaustion during chronic TB. Second, we evaluate the role of the inhibitory receptor T cell immunoglobulin and mucin domain–containing-3 (TIM3) during chronic M. tuberculosis infection. We find that TIM3 expressing T cells accumulate during chronic infection, co-express other inhibitory receptors including PD1, produce less IL-2 and TNF but more IL-10, and are functionally exhausted. Finally, we show that TIM3 blockade restores T cell function and improves bacterial control, particularly in chronically infected susceptible mice. These data show that T cell immunity is suboptimal during chronic M. tuberculosis infection due to T cell exhaustion. Moreover, in chronically infected mice, treatment with anti-TIM3 mAb is an effective therapeutic strategy against tuberculosis. PMID:26967901

  8. HIV integration site distributions in resting and activated CD4+ T cells infected in culture

    PubMed Central

    Brady, Troy; Agosto, Luis M.; Malani, Nirav; Berry, Charles C.; O'Doherty, Una; Bushman, Frederic

    2010-01-01

    Objective The goal of this study was to investigate whether the location of HIV integration differs in resting versus activated T cells, a feature that could contribute to the formation of latent viral reservoirs via effects on integration targeting. Design Primary resting or activated CD4+ T cells were infected with purified X4-tropic HIV in the presence and absence of nucleoside triphosphates and genomic locations of integrated provirus determined. Methods We sequenced and analyzed a total of 2661 HIV integration sites using linker-mediated PCR and 454 sequencing. Integration site data sets were then compared to each other and to computationally generated random distributions. Results HIV integration was favored in active transcription units in both cell types, but integration sites from activated cells were found more often in genomic regions that were dense in genes, dense in CpG islands, and enriched in G/C bases. Integration sites from activated cells were also more strongly correlated with histone methylation patterns associated with active genes. Conclusion These data indicate that integration site distributions show modest but significant differences between resting and activated CD4+ T cells, and that integration in resting cells occurs more often in regions that may be suboptimal for proviral gene expression. PMID:19550285

  9. Effect of Cell Physiological State on Infection by Rat Virus

    PubMed Central

    Tennant, Raymond W.; Layman, Kenneth R.; Hand, Russell E.

    1969-01-01

    Infection by rat virus has been studied in cultures of rat embryo cells to evaluate the Margolis-Kilham hypothesis that the virus preferentially infects tissues with actively dividing cells. An enhancement of infection was seen in cultures infected 10 hr after fresh medium was added as compared to infection of stationary cultures (infected before addition of fresh medium). Since addition of fresh medium stimulates deoxyribonucleic acid (DNA) synthesis, the number of cells per culture synthesizing DNA at the time of infection was compared with the proportion of cells which synthesized viral protein. Cells were infected before the medium change and 10 or 24 hr after the medium change and were pulse-labeled with 3H-thymidine at the time virus was added. The cells were allowed to initiate viral protein synthesis before they were fixed and stained with fluorescein-conjugated anti-rat virus serum. Fluorescence microscopy permitted both labels to be counted simultaneouly and showed that the greatest proportion of cells synthesizing viral protein were those which had incorporated 3H-thymidine at the time of infection. Images PMID:16789120

  10. Gnidimacrin, a Potent Anti-HIV Diterpene, Can Eliminate Latent HIV-1 Ex Vivo by Activation of Protein Kinase C β.

    PubMed

    Lai, Weihong; Huang, Li; Zhu, Lei; Ferrari, Guido; Chan, Cliburn; Li, Wei; Lee, Kuo-Hsiung; Chen, Chin-Ho

    2015-11-12

    HIV-1-latency-reversing agents, such as histone deacetylase inhibitors (HDACIs), were ineffective in reducing latent HIV-1 reservoirs ex vivo using CD4 cells from patients as a model. This deficiency poses a challenge to current pharmacological approaches for HIV-1 eradication. The results of this study indicated that gnidimacrin (GM) was able to markedly reduce the latent HIV-1 DNA level and the frequency of latently infected cells in an ex vivo model using patients peripheral blood mononuclear cells. GM induced approximately 10-fold more HIV-1 production than the HDACI SAHA or romidepsin, which may be responsible for the effectiveness of GM in reducing latent HIV-1 levels. GM achieved these effects at low picomolar concentrations by selective activation of protein kinase C βI and βII. Notably, GM was able to reduce the frequency of HIV-1 latently infected cells at concentrations without global T cell activation or stimulating inflammatory cytokine production. GM merits further development as a clinical trial candidate for latent HIV-1 eradication. PMID:26509731

  11. Macrophage Infection via Selective Capture of HIV-1-Infected CD4+ T Cells

    PubMed Central

    Baxter, Amy E.; Russell, Rebecca A.; Duncan, Christopher J.A.; Moore, Michael D.; Willberg, Christian B.; Pablos, Jose L.; Finzi, Andrés; Kaufmann, Daniel E.; Ochsenbauer, Christina; Kappes, John C.; Groot, Fedde; Sattentau, Quentin J.

    2014-01-01

    Summary Macrophages contribute to HIV-1 pathogenesis by forming a viral reservoir and mediating neurological disorders. Cell-free HIV-1 infection of macrophages is inefficient, in part due to low plasma membrane expression of viral entry receptors. We find that macrophages selectively capture and engulf HIV-1-infected CD4+ T cells leading to efficient macrophage infection. Infectedcells, both healthy and dead or dying, were taken up through viral envelope glycoprotein-receptor-independent interactions, implying a mechanism distinct from conventional virological synapse formation. Macrophages infected by this cell-to-cell route were highly permissive for both CCR5-using macrophage-tropic and otherwise weakly macrophage-tropic transmitted/founder viruses but restrictive for nonmacrophage-tropic CXCR4-using virus. These results have implications for establishment of the macrophage reservoir and HIV-1 dissemination in vivo. PMID:25467409

  12. Cytokines and T-Cell Homeostasis in HIV Infection.

    PubMed

    Freeman, Michael L; Shive, Carey L; Nguyen, Thao P; Younes, Souheil-Antoine; Panigrahi, Soumya; Lederman, Michael M

    2016-10-01

    Untreated human immunodeficiency virus (HIV) infection is characterized by progressive CD4(+) T-cell depletion and CD8(+) T-cell expansion, and CD4(+) T-cell depletion is linked directly to the risk for opportunistic infections and infection-associated mortality. With suppression of HIV replication by antiretroviral therapy, circulating CD4(+) Tcell numbers typically improve while CD8(+) T-cell expansion persists, and both CD4(+) T-cell cytopenia and CD8(+) T-cell expansion are associated with morbidity and mortality. In this brief review, we report on the role that selected homeostatic and inflammatory cytokines may play both in the failure of CD4(+) T-cell restoration and the CD8(+) T-cell expansion that characterize HIV infection. PMID:27625431

  13. Direct Transfer of Viral and Cellular Proteins from Varicella-Zoster Virus-Infected Non-Neuronal Cells to Human Axons

    PubMed Central

    Grigoryan, Sergei; Yee, Michael B; Glick, Yair; Gerber, Doron; Kepten, Eldad; Garini, Yuval; Yang, In Hong; Kinchington, Paul R.; Goldstein, Ronald S.

    2015-01-01

    Varicella Zoster Virus (VZV), the alphaherpesvirus that causes varicella upon primary infection and Herpes zoster (shingles) following reactivation in latently infected neurons, is known to be fusogenic. It forms polynuclear syncytia in culture, in varicella skin lesions and in infected fetal human ganglia xenografted to mice. After axonal infection using VZV expressing green fluorescent protein (GFP) in compartmentalized microfluidic cultures there is diffuse filling of axons with GFP as well as punctate fluorescence corresponding to capsids. Use of viruses with fluorescent fusions to VZV proteins reveals that both proteins encoded by VZV genes and those of the infecting cell are transferred in bulk from infecting non-neuronal cells to axons. Similar transfer of protein to axons was observed following cell associated HSV1 infection. Fluorescence recovery after photobleaching (FRAP) experiments provide evidence that this transfer is by diffusion of proteins from the infecting cells into axons. Time-lapse movies and immunocytochemical experiments in co-cultures demonstrate that non-neuronal cells fuse with neuronal somata and proteins from both cell types are present in the syncytia formed. The fusogenic nature of VZV therefore may enable not only conventional entry of virions and capsids into axonal endings in the skin by classical entry mechanisms, but also by cytoplasmic fusion that permits viral protein transfer to neurons in bulk. PMID:25973990

  14. CD4 Depletion in SIV-Infected Macaques Results in Macrophage and Microglia Infection with Rapid Turnover of Infected Cells

    PubMed Central

    Ortiz, Alexandra M.; Ryan, Emily S.; McGary, Colleen S.; Deleage, Claire; McAtee, Brigitte B.; He, Tianyu; Apetrei, Cristian; Easley, Kirk; Pahwa, Savita; Collman, Ronald G.; Derdeyn, Cynthia A.; Davenport, Miles P.; Estes, Jacob D.; Silvestri, Guido; Lackner, Andrew A.; Paiardini, Mirko

    2014-01-01

    In rhesus macaques (RMs), experimental depletion of CD4+ T-cells prior to SIV infection results in higher viremia and emergence of CD4-independent SIV-envelopes. In this study we used the rhesus recombinant anti-CD4 antibody CD4R1 to deplete RM CD4+ T-cells prior to SIVmac251 infection and investigate the sources of the increased viral burden and the lifespan of productively infected cells. CD4-depleted animals showed (i) set-point viral load two-logs higher than controls; (ii) macrophages constituting 80% of all SIV vRNA+ cells in lymph node and mucosal tissues; (iii) substantial expansion of pro-inflammatory monocytes; (iv) aberrant activation and infection of microglial cells; and (v) lifespan of productively infected cells significantly longer in comparison to controls, but markedly shorter than previously estimated for macrophages. The net effect of CD4+ T-cell depletion is an inability to control SIV replication and a shift in the tropism of infected cells to macrophages, microglia, and, potentially, other CD4-low cells which all appear to have a shortened in vivo lifespan. We believe these findings have important implications for HIV eradication studies. PMID:25356757

  15. Cytotoxic cells induced after Chlamydia psittaci infection in mice

    SciTech Connect

    Lammert, J.K.

    1982-03-01

    The ability of spleen cells from Chlamydia psittaci-infected mice to lyse C. psittaci-infected and uninfected target cell monolayers was studied. The cytotoxicity assay used was a terminal label method in which the number of adherent target cells surviving the interaction with effector cells was determined by measuring the uptake of (3H)uridine by such cells. It was observed that in the first few days postinfection (3 to 5), spleens contained cells that lysed infected and uninfected targets with equal efficiency. Subsequently, infected targets were killed primarily. The activity of effector spleen cells for infected targets continued, although at a reduced level, beyond 21 days postinfection. Intact effector cells were required since a disruption by sonication resulted in a loss of cytotoxicity. The enhanced killing observed with infected targets was also observed when target cells were sensitized with heat- or UV-inactivated C. psittaci. This study suggests that the induction of cytotoxic cells after C. psittaci infection may contribute to the ability of the host to control multiplication of the microorganism.

  16. Immune Function and Reactivation of Latent Viruses

    NASA Technical Reports Server (NTRS)

    Butel, Janet S.

    1999-01-01

    A major concern associated with long-duration space flight is the possibility of infectious diseases posing an unacceptable medical risk to crew members. One major hypothesis addressed in this project is that space flight will cause alterations in the immune system that will allow latent viruses that are endogenous in the human population to reactivate and shed to higher levels than normal, which may affect the health of crew members. The second major hypothesis being examined is that the effects of space flight will alter the mucosal immune system, the first line of defense against many microbial infections, including herpesviruses, polyomaviruses, and gastroenteritis viruses, rendering crew members more susceptible to virus infections across the mucosa. We are focusing the virus studies on the human herpesviruses and polyomaviruses, important pathogens known to establish latent infections in most of the human population. Both primary infection and reactivation from latent infection with these groups of viruses (especially certain herpesviruses) can cause a variety of illnesses that result in morbidity and, occasionally, mortality. Both herpesviruses and polyomaviruses have been associated with human cancer, as well. Effective vaccines exist for only one of the eight known human herpesviruses and available antivirals are of limited use. Whereas normal individuals display minimal consequences from latent viral infections, events which alter immune function (such as immunosuppressive therapy following solid organ transplantation) are known to increase the risk of complications as a result of viral reactivations.

  17. Suppression of HIV-1 Infectivity by Human Glioma Cells.

    PubMed

    Hoque, Sheikh Ariful; Tanaka, Atsushi; Islam, Salequl; Ahsan, Gias Uddin; Jinno-Oue, Atsushi; Hoshino, Hiroo

    2016-05-01

    HIV-1 infection to the central nervous system (CNS) is very common in AIDS patients. The predominant cell types infected in the brain are monocytes and macrophages, which are surrounded by several HIV-1-resistant cell types, such as astrocytes, oligodendrocytes, neurons, and microvascular cells. The effect of these HIV-1-resistant cells on HIV-1 infection is largely unknown. In this study, we examined the stability of HIV-1 cultured with several human glioblastoma cell lines, for example, NP-2, U87MG, T98G, and A172, to determine whether these HIV-1-resistant brain cells could enhance or suppress HIV-1 infection and thus modulate HIV-1 infection in the CNS. The HIV-1 titer was determined using the MAGIC-5A indicator cell line as well as naturally occurring CD4(+) T cells. We found that the stability of HIV-1 incubated with NP-2 or U87MG cells at 37°C was significantly shorter (half-life, 2.5-4 h) compared to that of HIV-1 incubated with T98G or A172 cells or in culture medium without cells (half-life, 8-18 h). The spent culture media (SCM) of NP-2 and U87MG cells had the ability to suppress both R5- and X4-HIV-1 infection by inhibiting HIV-1 attachment to target cells. This inhibitory effect was eliminated by the treatment of the SCM with chondroitinase ABC but not heparinase, suggesting that the inhibitory factor(s) secreted by NP-2 and U87MG cells was chiefly mediated by chondroitin sulfate (CS) or CS-like moiety. Thus, this study reveals that some but not all glioma cells secrete inhibitory molecules to HIV-1 infection that may contribute in lowering HIV-1 infection in the CNS in vivo. PMID:26650729

  18. Intracellular Events and Cell Fate in Filovirus Infection

    PubMed Central

    Olejnik, Judith; Ryabchikova, Elena; Corley, Ronald B.; Mühlberger, Elke

    2011-01-01

    Marburg and Ebola viruses cause a severe hemorrhagic disease in humans with high fatality rates. Early target cells of filoviruses are monocytes, macrophages, and dendritic cells. The infection spreads to the liver, spleen and later other organs by blood and lymph flow. A hallmark of filovirus infection is the depletion of non-infected lymphocytes; however, the molecular mechanisms leading to the observed bystander lymphocyte apoptosis are poorly understood. Also, there is limited knowledge about the fate of infected cells in filovirus disease. In this review we will explore what is known about the intracellular events leading to virus amplification and cell damage in filovirus infection. Furthermore, we will discuss how cellular dysfunction and cell death may correlate with disease pathogenesis. PMID:21927676

  19. MAIT cells are activated during human viral infections.

    PubMed

    van Wilgenburg, Bonnie; Scherwitzl, Iris; Hutchinson, Edward C; Leng, Tianqi; Kurioka, Ayako; Kulicke, Corinna; de Lara, Catherine; Cole, Suzanne; Vasanawathana, Sirijitt; Limpitikul, Wannee; Malasit, Prida; Young, Duncan; Denney, Laura; Moore, Michael D; Fabris, Paolo; Giordani, Maria Teresa; Oo, Ye Htun; Laidlaw, Stephen M; Dustin, Lynn B; Ho, Ling-Pei; Thompson, Fiona M; Ramamurthy, Narayan; Mongkolsapaya, Juthathip; Willberg, Christian B; Screaton, Gavin R; Klenerman, Paul

    2016-01-01

    Mucosal-associated invariant T (MAIT) cells are abundant in humans and recognize bacterial ligands. Here, we demonstrate that MAIT cells are also activated during human viral infections in vivo. MAIT cells activation was observed during infection with dengue virus, hepatitis C virus and influenza virus. This activation-driving cytokine release and Granzyme B upregulation-is TCR-independent but dependent on IL-18 in synergy with IL-12, IL-15 and/or interferon-α/β. IL-18 levels and MAIT cell activation correlate with disease severity in acute dengue infection. Furthermore, HCV treatment with interferon-α leads to specific MAIT cell activation in vivo in parallel with an enhanced therapeutic response. Moreover, TCR-independent activation of MAIT cells leads to a reduction of HCV replication in vitro mediated by IFN-γ. Together these data demonstrate MAIT cells are activated following viral infections, and suggest a potential role in both host defence and immunopathology. PMID:27337592

  20. MAIT cells are activated during human viral infections

    PubMed Central

    van Wilgenburg, Bonnie; Scherwitzl, Iris; Hutchinson, Edward C.; Leng, Tianqi; Kurioka, Ayako; Kulicke, Corinna; de Lara, Catherine; Cole, Suzanne; Vasanawathana, Sirijitt; Limpitikul, Wannee; Malasit, Prida; Young, Duncan; Denney, Laura; Barnes, Eleanor; Ball, Jonathan; Burgess, Gary; Cooke, Graham; Dillon, John; Gore, Charles; Foster, Graham; Guha, Neil; Halford, Rachel; Herath, Cham; Holmes, Chris; Howe, Anita; Hudson, Emma; Irving, William; Khakoo, Salim; Koletzki, Diana; Martin, Natasha; Mbisa, Tamyo; McKeating, Jane; McLauchlan, John; Miners, Alec; Murray, Andrea; Shaw, Peter; Simmonds, Peter; Spencer, Chris; Targett-Adams, Paul; Thomson, Emma; Vickerman, Peter; Zitzmann, Nicole; Moore, Michael D.; Fabris, Paolo; Giordani, Maria Teresa; Oo, Ye Htun; Laidlaw, Stephen M.; Dustin, Lynn B.; Ho, Ling-Pei; Thompson, Fiona M.; Ramamurthy, Narayan; Mongkolsapaya, Juthathip; Willberg, Christian B.; Screaton, Gavin R.; Klenerman, Paul

    2016-01-01

    Mucosal-associated invariant T (MAIT) cells are abundant in humans and recognize bacterial ligands. Here, we demonstrate that MAIT cells are also activated during human viral infections in vivo. MAIT cells activation was observed during infection with dengue virus, hepatitis C virus and influenza virus. This activation—driving cytokine release and Granzyme B upregulation—is TCR-independent but dependent on IL-18 in synergy with IL-12, IL-15 and/or interferon-α/β. IL-18 levels and MAIT cell activation correlate with disease severity in acute dengue infection. Furthermore, HCV treatment with interferon-α leads to specific MAIT cell activation in vivo in parallel with an enhanced therapeutic response. Moreover, TCR-independent activation of MAIT cells leads to a reduction of HCV replication in vitro mediated by IFN-γ. Together these data demonstrate MAIT cells are activated following viral infections, and suggest a potential role in both host defence and immunopathology. PMID:27337592

  1. Highly potent, synthetically accessible prostratin analogs induce latent HIV expression in vitro and ex vivo

    PubMed Central

    Beans, Elizabeth J.; Fournogerakis, Dennis; Gauntlett, Carolyn; Heumann, Lars V.; Kramer, Rainer; Marsden, Matthew D.; Murray, Danielle; Zack, Jerome A.; Wender, Paul A.

    2013-01-01

    Highly active antiretroviral therapy (HAART) decreases plasma viremia below the limits of detection in the majority of HIV-infected individuals, thus serving to slow disease progression. However, HAART targets only actively replicating virus and is unable to eliminate latently infected, resting CD4+ T cells. Such infected cells are potentially capable of reinitiating virus replication upon cessation of HAART, thus leading to viral rebound. Agents that would eliminate these reservoirs, when used in combination with HAART, could thus provide a strategy for the eradication of HIV. Prostratin is a preclinical candidate that induces HIV expression from latently infected CD4+ T cells, potentially leading to their elimination through a virus-induced cytopathic effect or host anti-HIV immunity. Here, we report the synthesis of a series of designed prostratin analogs and report in vitro and ex vivo studies of their activity relevant to induction of HIV expression. Members of this series are up to 100-fold more potent than the preclinical lead (prostratin) in binding to cell-free PKC, and in inducing HIV expression in a latently infected cell line and prostratin-like modulation of cell surface receptor expression in primary cells from HIV-negative donors. Significantly, selected members were also tested for HIV induction in resting CD4+ T cells isolated from infected individuals receiving HAART and were found to exhibit potent induction activity. These more potent agents and by extension related tunable analogs now accessible through the studies described herein should facilitate research and preclinical advancement of this strategy for HIV/AIDS eradication. PMID:23812750

  2. On latent fingerprint enhancement

    NASA Astrophysics Data System (ADS)

    Yoon, Soweon; Feng, Jianjiang; Jain, Anil K.

    2010-04-01

    Automatic feature extraction in latent fingerprints is a challenging problem due to poor quality of most latents, such as unclear ridge structures, overlapped lines and letters, and overlapped fingerprints. We proposed a latent fingerprint enhancement algorithm which requires manually marked region of interest (ROI) and singular points. The core of the proposed enhancement algorithm is a novel orientation field estimation algorithm, which fits orientation field model to coarse orientation field estimated from skeleton outputted by a commercial fingerprint SDK. Experimental results on NIST SD27 latent fingerprint database indicate that by incorporating the proposed enhancement algorithm, the matching accuracy of the commercial matcher was significantly improved.

  3. Synergistic Activation of Latent HIV-1 Expression by Novel Histone Deacetylase Inhibitors and Bryostatin-1

    PubMed Central

    Martínez-Bonet, Marta; Isabel Clemente, Maria; Jesús Serramía, Maria; Muñoz, Eduardo; Moreno, Santiago; Ángeles Muñoz-Fernández, Maria

    2015-01-01

    Viral reactivation from latently infected cells has become a promising therapeutic approach to eradicate HIV. Due to the complexity of the viral latency, combinations of efficient and available drugs targeting different pathways of latency are needed. In this work, we evaluated the effect of various combinations of bryostatin-1 (BRY) and novel histone deacetylase inhibitors (HDACIs) on HIV-reactivation and on cellular phenotype. The lymphocyte (J89GFP) or monocyte/macrophage (THP89GFP) latently infected cell lines were treated with BRY, panobinostat (PNB) and romidepsin (RMD) either alone or in combination. Thus, the effect on the viral reactivation was evaluated. We calculated the combination index for each drug combination; the BRY/HDACIs showed a synergistic HIV-reactivation profile in the majority of the combinations tested, whereas non-synergistic effects were observed when PNB was mixed with RMD. Indeed, the 75% effective concentrations of BRY, PNB and RMD were reduced in these combinations. Moreover, primary CD4 T cells treated with such drug combinations presented similar activation and proliferation profiles in comparison with single drug treated cells. Summing up, combinations between BRY, PNB and/or RMD presented a synergistic profile by inducing virus expression in HIV-latently infected cells, rendering these combinations an attractive novel and safe option for future clinical trials. PMID:26563568

  4. A novel mechanism inducing genome instability in Kaposi's sarcoma-associated herpesvirus infected cells.

    PubMed

    Jackson, Brian R; Noerenberg, Marko; Whitehouse, Adrian

    2014-05-01

    Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic herpesvirus associated with multiple AIDS-related malignancies. Like other herpesviruses, KSHV has a biphasic life cycle and both the lytic and latent phases are required for tumorigenesis. Evidence suggests that KSHV lytic replication can cause genome instability in KSHV-infected cells, although no mechanism has thus far been described. A surprising link has recently been suggested between mRNA export, genome instability and cancer development. Notably, aberrations in the cellular transcription and export complex (hTREX) proteins have been identified in high-grade tumours and these defects contribute to genome instability. We have previously shown that the lytically expressed KSHV ORF57 protein interacts with the complete hTREX complex; therefore, we investigated the possible intriguing link between ORF57, hTREX and KSHV-induced genome instability. Herein, we show that lytically active KSHV infected cells induce a DNA damage response and, importantly, we demonstrate directly that this is due to DNA strand breaks. Furthermore, we show that sequestration of the hTREX complex by the KSHV ORF57 protein leads to this double strand break response and significant DNA damage. Moreover, we describe a novel mechanism showing that the genetic instability observed is a consequence of R-loop formation. Importantly, the link between hTREX sequestration and DNA damage may be a common feature in herpesvirus infection, as a similar phenotype was observed with the herpes simplex virus 1 (HSV-1) ICP27 protein. Our data provide a model of R-loop induced DNA damage in KSHV infected cells and describes a novel system for studying genome instability caused by aberrant hTREX. PMID:24788796

  5. Human NK Cell Diversity in Viral Infection: Ramifications of Ramification

    PubMed Central

    Strauss-Albee, Dara M.; Blish, Catherine A.

    2016-01-01

    Natural killer (NK) cells are a unique lymphocyte lineage with remarkable agility in the rapid destruction of virus-infected cells. They are also the most poorly understood class of lymphocyte. A spectrum of activating and inhibitory receptors at the NK cell surface leads to an unusual and difficult-to-study mechanism of cellular recognition, as well as a very high capacity for diversity at the single-cell level. Here, we review the evidence for the role of NK cells in the earliest stage of human viral infection, and in its prevention. We argue that single-cell diversity is a logical evolutionary adaptation for their position in the immune response and contributes to their ability to kill virus-infected cells. Finally, we look to the future, where emerging single-cell technologies will enable a new generation of rigorous and clinically relevant studies on NK cells accounting for all of their unique and diverse characteristics. PMID:26973646

  6. Infection of simian B lymphoblastoid cells with simian immunodeficiency virus is associated with upregulation of CD23 and CD40 cell surface markers.

    PubMed

    Titti, Fausto; Zamarchi, Rita; Maggiorella, Maria Teresa; Sernicola, Leonardo; Geraci, Andrea; Negri, Donatella Rita Maria; Borsetti, Alessandra; Menin, Chiara; D'Andrea, Emma; Modesti, Andrea; Masuelli, Laura; Verani, Paola; Chieco-Bianchi, Luigi; Amadori, Alberto

    2002-09-01

    Simian immunodeficiency virus (SIV) as well as human immunodeficiency virus (HIV) induce polyclonal B-cell activation and are associated with the appearance of lymphomas in their respective hosts in either the presence or the absence of other co-infecting viruses such as Epstein-Barr virus (EBV). However, the pathogenic role of these retroviruses in the development of lymphoproliferative disorders remains poorly understood. To explore the virus-B-cell interactions, two immortalized lymphoblastoid B-cell lines (SL-P1 and SL-691) were established from cynomolgus monkeys that were naturally co-infected with a simian type D retrovirus-2 (SRV-2) and with the herpes virus Macaca fascicularis (HVMF-1). We addressed their susceptibility to SIV infection and the phenotypic modifications associated with SIV infection. In response, both cell lines (1) were co-infected with HVMF-1 (latent infection) and with SRV-2 (productive infection), (2) had a transformed phenotype because they did not require exogenous growth factors, and (3) when injected into mice with severe combined immunodeficiency (SCID), generated serially transplantable tumors. The B-cell origin of SL cells was demonstrated by the presence of rearrangements of the IgH gene and by the expression of typical B-cell lineage markers, such as CD20. SL-P1 and SL-691 could be discriminated on the basis of different expressions of CD23 and CD40 and of kappa- and lambda-chains. Most importantly, SL-691 cells, but not SL-P1 cells, were susceptible to chronic noncytolytic SIV infection. This infection occurred in a CD4/CCR5/CXCR4-independent manner and was associated with the upregulated expression of CD23 and CD40 cell surface markers. In addition, CD20 expression, which progressively disappeared in SL-691 noninfected cells, was maintained in the SIV-infected counterpart. These findings support the hypothesis that SIV induce phenotypic perturbations in B cells that might eventually contribute to the development of

  7. The CD8+ T-Cell Response to an Epstein-Barr Virus-Related Gammaherpesvirus Infecting Rhesus Macaques Provides Evidence for Immune Evasion by the EBNA-1 Homologue

    PubMed Central

    Fogg, Mark H.; Kaur, Amitinder; Cho, Young-Gyu; Wang, Fred

    2005-01-01

    Epstein-Barr virus (EBV) infection persists for life in humans, similar to other gammaherpesviruses in the same lymphocryptovirus (LCV) genus that naturally infect Old World nonhuman primates. The specific immune elements required for control of EBV infection and potential immune evasion strategies essential for persistent EBV infection are not well defined. We evaluated the cellular immune response to latent infection proteins in rhesus macaques with naturally and experimentally acquired rhesus LCV (rhLCV) infection. RhLCV EBNA-1 (rhEBNA-1) was the most frequently targeted latent infection protein and induced the most robust responses by peripheral blood mononuclear cells tested ex vivo using the gamma interferon ELISPOT assay. In contrast, although in vitro stimulation and expansion of rhLCV-specific T lymphocytes demonstrated cytotoxic T-lymphocyte (CTL) activity against autologous rhLCV-infected B cells, rhEBNA-1-specific CTL activity could not be detected. rhEBNA-1 CTL epitopes were identified and demonstrated that rhEBNA-1-specific CTL were stimulated and expanded in vitro but did not lyse targets expressing rhEBNA-1. Similarly, rhEBNA-1-specific CTL clones were able to lyse targets pulsed with rhEBNA-1 peptides or expressing rhEBNA-1 deleted for the glycine-alanine repeat (GAR) but not full-length rhEBNA-1 or rhLCV-infected B cells. These studies show that the rhLCV-specific immune response to latent infection proteins is similar to the EBV response in humans, and a potential immune evasion mechanism for EBNA-1 has been conserved in rhLCV. Thus, the rhLCV animal model can be used to analyze the immune responses important for control of persistent LCV infection and the role of the EBNA-1 GAR for immune evasion in vivo. PMID:16188971

  8. A dichotomy in cortical actin and chemotactic actin activity between human memory and naive T cells contributes to their differential susceptibility to HIV-1 infection.

    PubMed

    Wang, Weifeng; Guo, Jia; Yu, Dongyang; Vorster, Paul J; Chen, WanJun; Wu, Yuntao

    2012-10-12

    Human memory and naive CD4 T cells can mainly be identified by the reciprocal expression of the CD45RO or CD45RA isoforms. In HIV-1 infection, blood CD45RO memory CD4 T cells are preferentially infected and serve as a major viral reservoir. The molecular mechanism dictating this differential susceptibility to HIV-1 remains largely obscure. Here, we report that the different susceptibility of memory and naive T cells to HIV is not determined by restriction factors such as Apobec3G or BST2. However, we observed a phenotypic distinction between human CD45RO and CD45RA resting CD4 T cells in their cortical actin density and actin dynamics. CD45RO CD4 T cells possess a higher cortical actin density and can be distinguished as CD45RO(+)Actin(high). In contrast, CD45RA T cells are phenotypically CD45RA(+)Actin(low). In addition, the cortical actin in CD45RO memory CD4 T cells is more dynamic and can respond to low dosages of chemotactic induction by SDF-1, whereas that of naive cells cannot, despite a similar level of the chemokine receptor CXCR4 present on both cells. We further demonstrate that this difference in the cortical actin contributes to their differential susceptibility to HIV-1; resting memory but not naive T cells are highly responsive to HIV-mediated actin dynamics that promote higher levels of viral entry and early DNA synthesis in resting memory CD4 T cells. Furthermore, transient induction of actin dynamics in resting naive T cells rescues HIV latent infection following CD3/CD28 stimulation. These results suggest a key role of chemotactic actin activity in facilitating HIV-1 latent infection of these T cell subsets. PMID:22879601

  9. Late steps of parvoviral infection induce changes in cell morphology.

    PubMed

    Pakkanen, Kirsi; Nykky, Jonna; Vuento, Matti

    2008-11-01

    Previously, virus-induced non-filopodial extensions have not been encountered in connection with viral infections. Here, we report emergence of long extensions protruding from Norden laboratory feline kidney (NLFK) and A72 (canine fibroma) cells infected with canine parvovirus for 72 h. These extensions significantly differ in length and number from those appearing in control cells. The most striking feature in the extensions is the length, reaching up to 130 microm, almost twice the average length of a healthy NLFK cell. In A72 cells, the extensions were even longer, up to 200 microm. The results presented here also suggest that the events leading to the growth of these extensions start earlier in infection and abnormal extension growth is detectable already at 24-h post-infection (p.i.). These extensions may have a vital role in the cell-to-cell transmission of the virus. PMID:18718495

  10. CD8+ T cells control Ross River virus infection in musculoskeletal tissues of infected mice.

    PubMed

    Burrack, Kristina S; Montgomery, Stephanie A; Homann, Dirk; Morrison, Thomas E

    2015-01-15

    Ross River virus (RRV), chikungunya virus, and related alphaviruses cause debilitating polyarthralgia and myalgia. Mouse models of RRV and chikungunya virus have demonstrated a role for the adaptive immune response in the control of these infections. However, questions remain regarding the role for T cells in viral control, including the magnitude, location, and dynamics of CD8(+) T cell responses. To address these questions, we generated a recombinant RRV expressing the H-2(b)-restricted glycoprotein 33 (gp33) determinant derived from the glycoprotein of lymphocytic choriomeningitis virus. Using tetramers, we tracked gp33-specific CD8(+) T cells during RRV-lymphocytic choriomeningitis virus infection. We found that acute RRV infection induces activation of CD8(+) T cell responses in lymphoid and musculoskeletal tissues that peak from 10-14 d postinoculation, suggesting that CD8(+) T cells contribute to control of acute RRV infection. Mice genetically deficient for CD8(+) T cells or wild-type mice depleted of CD8(+) T cells had elevated RRV loads in skeletal muscle tissue, but not joint-associated tissues, at 14 d postinoculation, suggesting that the ability of CD8(+) T cells to control RRV infection is tissue dependent. Finally, adoptively transferred T cells were capable of reducing RRV loads in skeletal muscle tissue of Rag1(-/-) mice, indicating that T cells can contribute to the control of RRV infection in the absence of B cells and Ab. Collectively, these data demonstrate a role for T cells in the control of RRV infection and suggest that the antiviral capacity of T cells is controlled in a tissue-specific manner. PMID:25488988

  11. CD8+ T cells control Ross River virus infection in musculoskeletal tissues of infected mice

    PubMed Central

    Burrack, Kristina S.; Montgomery, Stephanie A.; Homann, Dirk; Morrison, Thomas E.

    2014-01-01

    Ross River virus (RRV), chikungunya virus (CHIKV), and related alphaviruses cause debilitating polyarthralgia and myalgia. Mouse models of RRV and CHIKV have demonstrated a role for the adaptive immune response in the control of these infections. However, questions remain regarding the role for T cells in viral control, including the magnitude, location, and dynamics of CD8+ T cell responses. To address these questions, we generated a recombinant RRV expressing the H-2b-restricted gp33 determinant derived from the glycoprotein (gp) of lymphocytic choriomeningitis virus (LCMV) (“RRV-LCMV”). Utilizing tetramers, we tracked gp33-specific CD8+ T cells during RRV-LCMV infection. We found that acute RRV infection induces activation of CD8+ T cell responses in lymphoid and musculoskeletal tissues that peak from 10 to 14 days post-inoculation (dpi), suggesting that CD8+ T cells contribute to control of acute RRV infection. Mice genetically deficient for CD8+ T cells or wild-type mice depleted of CD8+ T cells had elevated RRV loads in skeletal muscle tissue, but not joint-associated tissues, at 14 dpi, suggesting that the ability of CD8+ T cells to control RRV infection is tissue-dependent. Finally, adoptively transferred T cells were capable of reducing RRV loads in skeletal muscle tissue of Rag1−/− mice, indicating that T cells can contribute to the control of RRV infection in the absence of B cells and antibody. Collectively, these data demonstrate a role for T cells in the control of RRV infection and suggest that the antiviral capacity of T cells is controlled in a tissue-specific manner. PMID:25488988

  12. Inapparent Viral Infection of Cells In Vitro III. Manifestations of Infection of L Mouse Cells by Japanese Encephalitis Virus1

    PubMed Central

    Dubbs, D. R.; Scherer, W. F.

    1966-01-01

    Dubbs, D. R. (University of Minnesota, Minneapolis), and W. F. Scherer. Inapparent viral infection of cells in vitro. III. Manifestations of infection of L mouse cells by Japanese encephalitis virus. J. Bacteriol. 91:2349–2355. 1966.—Nine strains of Japanese encephalitis (JE) virus were propagated serially in cultures of L cells reaching titers of 103.5 to 106.3. Although cytopathic effects were not seen in cultures of contiguous L cells after infection with JE virus, cell growth was inhibited. Moreover, cell destruction was readily apparent in infected cultures of sparse, noncontiguous L cells. Differences in the size of cell population of infected and noninfected cultures (i) occurred despite only 0.2 to 3.5% of the cells in infected cultures being associated with infectious virus, (ii) were greater in actively growing cultures than in those kept in maintenance media, and (iii) were probably in part related to an interferon produced in infected cultures. Images PMID:4287589

  13. Detection and quantification of Epstein-Barr virus EBER1 in EBV-infected cells by fluorescent in situ hybridization and flow cytometry

    NASA Technical Reports Server (NTRS)

    Stowe, R. P.; Cubbage, M. L.; Sams, C. F.; Pierson, D. L.; Barrett, A. D.

    1998-01-01

    A rapid and highly sensitive fluorescent in situ hybridization (FISH) assay was developed to detect Epstein Barr virus (EBV)-infected cells in peripheral blood. Multiple fluorescein-labeled antisense oligonucleotide probes were designed to hybridize to the EBER1 transcript, which is highly expressed in latently infected cells. After a rapid (30 min) hybridization, the cells were analyzed by flow cytometry. EBER1 was detected in several positive control cell lines that have variable numbers of EBV genome copies. No EBER1 was detected in two known EBV-negative cell lines. Northern blot analyses confirmed the presence and quantity of EBER1 transcripts in each cell line. This method was used to quantify the number of EBV-infected cells in peripheral blood from a patient with chronic mononucleosis. These results indicate that EBV-infected cells can be detected at the single cell level, and that this assay can be used to quantify the number of EBV-infected cells in clinical samples.

  14. In vivo infection of IgG-containing cells by Jembrana disease virus during acute infection

    SciTech Connect

    Desport, Moira; Tenaya, I.W. Masa; McLachlan, Alexander; McNab, Tegan J.; Rachmat, Judhi; Hartaningsih, Nining; Wilcox, Graham E.

    2009-10-25

    Jembrana disease virus (JDV) is an unusual bovine lentivirus which causes a non-follicular proliferation of lymphocytes, a transient immunosuppression and a delayed humoral response in infected Bali cattle in Indonesia. A double-immunofluorescent labeling method was developed to identify the subset of mononuclear cells in which the viral capsid protein could be detected. Viral antigen was present in pleomorphic centroblast-like cells which were identified as IgG-containing cells, including plasma cells, in lymphoid tissues. There was no evidence of infection of CD3{sup +} T-cells or MAC387{sup +} monocytes in tissues but large vacuolated cells with a macrophage-like morphology in the lung were found to contain viral antigen although they could not be shown conclusively to be infected. The tropism of JDV for mature IgG-containing cells may be relevant to understanding the pathogenesis of Jembrana disease, the delayed antibody responses and the genetic composition of this atypical lentivirus.

  15. Modeling multiple infection of cells by viruses: challenges and insights

    PubMed Central

    Phan, Dustin; Wodarz, Dominik

    2015-01-01

    The multiple infection of cells with several copies of a given virus has been demonstrated in experimental systems, and has been subject to previous mathematical modeling approaches. Such models, especially those based on ordinary differential equations, can be characterized by difficulties and pitfalls. One such difficulty arises from what we refer to as multiple infection cascades. That is, such models subdivide the infected cell population into sub-populations that are carry i viruses, and each sub-population can in principle always be further infected to contain i+1 viruses. In order to study the model with numerical simulations, the infection cascade needs to be cut artificially, and this can influence the results. This is shown here in the context of the simplest setting that involves a single, homogeneous virus population. If the viral replication rate is sufficiently fast, then most infected cells will accumulate in the last member of the infection cascade, leading to incorrect numerical results. This can be observed even with relatively long infection cascades, and in this case computational costs associated with a sufficiently long infection cascade can render this approach impractical. We subsequently examine a more complex scenario where two virus types / strains with different fitness are allowed to compete. Again, we find that the length of the infection cascade can have a crucial influence on the results. Competitive exclusion can be observed for shorter infection cascades, while coexistence can be observed for longer infection cascades. More subtly, the length of the infection cascade can influence the equilibrium level of the populations in numerical simulations. Studying the model in a parameter regime where an increase in the infection cascade length does not influence the results, we examine the effect of multiple infection on the outcome of competition. We find that multiple infection can promote coexistence of virus types if there is a degree

  16. Latent Variable Theory

    ERIC Educational Resources Information Center

    Borsboom, Denny

    2008-01-01

    This paper formulates a metatheoretical framework for latent variable modeling. It does so by spelling out the difference between observed and latent variables. This difference is argued to be purely epistemic in nature: We treat a variable as "observed" when the inference from data structure to variable structure can be made with certainty and as…

  17. Effect of parasitic infection on dopamine biosynthesis in dopaminergic cells

    PubMed Central

    Martin, H.L.; Alsaady, I.; Howell, G.; Prandovszky, E.; Peers, C.; Robinson, P.; McConkey, G.A.

    2015-01-01

    Infection by the neurotropic agent Toxoplasma gondii alters rodent behavior and can result in neuropsychiatric symptoms in humans. Little is understood regarding the effects of infection on host neural processes but alterations to dopaminergic neurotransmission are implicated. We have previously reported elevated levels of dopamine (DA) in infected dopaminergic cells however the involvement of the host enzymes and fate of the produced DA were not defined. In order to clarify the effects of infection on host DA biosynthetic enzymes and DA packaging we examined enzyme levels and activity and DA accumulation and release in T. gondii-infected neurosecretory cells. Although the levels of the host tyrosine hydroxylase (TH) and DOPA decarboxylase and AADC (DDC) did not change significantly in infected cultures, DDC was found within the parasitophorous vacuole (PV), the vacuolar compartment where the parasites reside, as well as in the host cytosol in infected dopaminergic cells. Strikingly, DDC was found within the intracellular parasite cysts in infected brain tissue. This finding could provide some explanation for observations of DA within tissue cysts in infected brain as a parasite-encoded enzyme with TH activity was also localized within tissue cysts. In contrast, cellular DA packaging appeared unchanged in single-cell microamperometry experiments and only a fraction of the increased DA was accessible to high potassium-induced release. This study provides some understanding of how this parasite produces elevated DA within dopaminergic cells without the toxic ramifications of free cytosolic DA. The mechanism for synthesis and packaging of DA by T. gondii-infected dopaminergic cells may have important implications for the effects of chronic T. gondii infection on humans and animals. PMID:26297895

  18. Post-treatment control of HIV infection

    SciTech Connect

    Conway, Jessica M.; Perelson, Alan S.

    2015-04-13

    Antiretroviral therapy (ART) for HIV is not a cure. However, recent studies suggest that ART, initiated early during primary infection, may induce post-treatment control (PTC) of HIV infection with HIV RNA maintained at <50 copies per mL. We investigate the hypothesis that ART initiated early during primary infection permits PTC by limiting the size of the latent reservoir, which, if small enough at treatment termination, may allow the adaptive immune response to prevent viral rebound (VR) and control infection. We use a mathematical model of within host HIV dynamics to capture interactions among target cells, productively infected cells, latently infected cells, virus, and cytotoxic T lymphocytes (CTLs). Analysis of our model reveals a range in CTL response strengths where a patient may show either VR or PTC, depending on the size of the latent reservoir at treatment termination. Below this range, patients will always rebound, whereas above this range, patients are predicted to behave like elite controllers. As a result, using data on latent reservoir sizes in patients treated during primary infection, we also predict population-level VR times for non-controllers consistent with observations.

  19. Cytomegalovirus-Infected Cells Resist T Cell Mediated Killing in an HLA-Recognition Independent Manner.

    PubMed

    Proff, Julia; Walterskirchen, Christian; Brey, Charlotte; Geyeregger, Rene; Full, Florian; Ensser, Armin; Lehner, Manfred; Holter, Wolfgang

    2016-01-01

    In order to explore the potential of HLA-independent T cell therapy for human cytomegalovirus (HCMV) infections, we developed a chimeric antigen receptor (CAR) directed against the HCMV encoded glycoprotein B (gB), which is expressed at high levels on the surface of infected cells. T cells engineered with this anti-gB CAR recognized HCMV-infected cells and released cytokines and cytotoxic granules. Unexpectedly, and in contrast to analogous approaches for HIV, Hepatitis B or Hepatitis C virus, we found that HCMV-infected cells were resistant to killing by the CAR-modified T cells. In order to elucidate whether this phenomenon was restricted to the use of CARs, we extended our experiments to T cell receptor (TCR)-mediated recognition of infected cells. To this end we infected fibroblasts with HCMV-strains deficient in viral inhibitors of antigenic peptide presentation and targeted these HLA-class I expressing peptide-loaded infected cells with peptide-specific cytotoxic T cells (CTLs). Despite strong degranulation and cytokine production by the T cells, we again found significant inhibition of lysis of HCMV-infected cells. Impairment of cell lysis became detectable 1 day after HCMV infection and gradually increased during the following 3 days. We thus postulate that viral anti-apoptotic factors, known to inhibit suicide of infected host cells, have evolved additional functions to directly abrogate T cell cytotoxicity. In line with this hypothesis, CAR-T cell cytotoxicity was strongly inhibited in non-infected fibroblasts by expression of the HCMV-protein UL37x1, and even more so by additional expression of UL36. Our data extend the current knowledge on Betaherpesviral evasion from T cell immunity and show for the first time that, beyond impaired antigen presentation, infected cells are efficiently protected by direct blockade of cytotoxic effector functions through viral proteins. PMID:27375569

  20. Cytomegalovirus-Infected Cells Resist T Cell Mediated Killing in an HLA-Recognition Independent Manner

    PubMed Central

    Proff, Julia; Walterskirchen, Christian; Brey, Charlotte; Geyeregger, Rene; Full, Florian; Ensser, Armin; Lehner, Manfred; Holter, Wolfgang

    2016-01-01

    In order to explore the potential of HLA-independent T cell therapy for human cytomegalovirus (HCMV) infections, we developed a chimeric antigen receptor (CAR) directed against the HCMV encoded glycoprotein B (gB), which is expressed at high levels on the surface of infected cells. T cells engineered with this anti-gB CAR recognized HCMV-infected cells and released cytokines and cytotoxic granules. Unexpectedly, and in contrast to analogous approaches for HIV, Hepatitis B or Hepatitis C virus, we found that HCMV-infected cells were resistant to killing by the CAR-modified T cells. In order to elucidate whether this phenomenon was restricted to the use of CARs, we extended our experiments to T cell receptor (TCR)-mediated recognition of infected cells. To this end we infected fibroblasts with HCMV-strains deficient in viral inhibitors of antigenic peptide presentation and targeted these HLA-class I expressing peptide-loaded infected cells with peptide-specific cytotoxic T cells (CTLs). Despite strong degranulation and cytokine production by the T cells, we again found significant inhibition of lysis of HCMV-infected cells. Impairment of cell lysis became detectable 1 day after HCMV infection and gradually increased during the following 3 days. We thus postulate that viral anti-apoptotic factors, known to inhibit suicide of infected host cells, have evolved additional functions to directly abrogate T cell cytotoxicity. In line with this hypothesis, CAR-T cell cytotoxicity was strongly inhibited in non-infected fibroblasts by expression of the HCMV-protein UL37x1, and even more so by additional expression of UL36. Our data extend the current knowledge on Betaherpesviral evasion from T cell immunity and show for the first time that, beyond impaired antigen presentation, infected cells are efficiently protected by direct blockade of cytotoxic effector functions through viral proteins. PMID:27375569

  1. Splenic Damage during SIV Infection: Role of T-Cell Depletion and Macrophage Polarization and Infection.

    PubMed

    Williams, Dionna W; Engle, Elizabeth L; Shirk, Erin N; Queen, Suzanne E; Gama, Lucio; Mankowski, Joseph L; Zink, M Christine; Clements, Janice E

    2016-08-01

    The effects of HIV infection on spleen and its cellular subsets have not been fully characterized, particularly for macrophages in which diverse populations exist. We used an accelerated SIV-infected macaque model to examine longitudinal effects on T-cell and macrophage populations and their susceptibilities to infection. Substantial lymphoid depletion occurred, characterized by follicular burn out and a loss of CD3 T lymphocytes, which was associated with cellular activation and transient dysregulations in CD4/CD8 ratios and memory effector populations. In contrast, the loss of CD68 and CD163(+)CD68(+) macrophages and increase in CD163 cells was irreversible, which began during acute infection and persisted until terminal disease. Mac387 macrophages and monocytes were transiently recruited into spleen, but were not sufficient to mitigate the changes in macrophage subsets. Type I interferon, M2 polarizing genes, and chemokine-chemokine receptor signaling were up-regulated in spleen and drove macrophage alterations. SIV-infected T cells were numerous within the white pulp during acute infection, but were rarely observed thereafter. CD68, CD163, and Mac387 macrophages were highly infected, which primarily occurred in the red pulp independent of T cells. Few macrophages underwent apoptosis, indicating that they are a long-lasting target for HIV/SIV. Our results identify macrophages as an important contributor to HIV/SIV infection in spleen and in promoting morphologic changes through the loss of specific macrophage subsets that mediate splenic organization. PMID:27322772

  2. The role of human dendritic cells in HIV-1 infection.

    PubMed

    Ahmed, Zahra; Kawamura, Tatsuyoshi; Shimada, Shinji; Piguet, Vincent

    2015-05-01

    Dendritic cells (DCs) and their subsets have multifaceted roles in the early stages of HIV-1 transmission and infection. DC studies have led to remarkable discoveries, including identification of restriction factors, cellular structures promoting viral transmission including the infectious synapse or the interplay of the C-type lectins, Langerin on Langerhans cells (LCs), and dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin on other DC subsets, limiting or facilitating HIV transmission to CD4(+) T cells, respectively. LCs/DCs are also exposed to encountering HIV-1 and other sexually transmitted infections (herpes simplex virus-2, bacteria, fungi), which reprogram HIV-1 interactio