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Sample records for latently infected cell

  1. Human Cytomegalovirus Manipulation of Latently Infected Cells

    PubMed Central

    Sinclair, John H.; Reeves, Matthew B.

    2013-01-01

    Primary infection with human cytomegalovirus (HCMV) results in the establishment of a lifelong infection of the host which is aided by the ability of HCMV to undergo a latent infection. One site of HCMV latency in vivo is in haematopoietic progenitor cells, resident in the bone marrow, with genome carriage and reactivation being restricted to the cells of the myeloid lineage. Until recently, HCMV latency has been considered to be relatively quiescent with the virus being maintained essentially as a “silent partner” until conditions are met that trigger reactivation. However, advances in techniques to study global changes in gene expression have begun to show that HCMV latency is a highly active process which involves expression of specific latency-associated viral gene products which orchestrate major changes in the latently infected cell. These changes are argued to help maintain latent infection and to modulate the cellular environment to the benefit of latent virus. In this review, we will discuss these new findings and how they impact not only on our understanding of the biology of HCMV latency but also how they could provide tantalising glimpses into mechanisms that could become targets for the clearance of latent HCMV. PMID:24284875

  2. Dual-Color HIV Reporters Trace a Population of Latently Infected Cells and Enable Their Purification

    PubMed Central

    Calvanese, Vincenzo; Chavez, Leonard; Laurent, Timothy; Ding, Sheng; Verdin, Eric

    2014-01-01

    SUMMARY HIV latency constitutes the main barrier for clearing HIV infection from patients. Our inability to recognize and isolate latently infected cells hinders the study of latent HIV. We engineered two HIV-based viral reporters expressing different fluorescent markers: one HIV promoter-dependent marker for productive HIV infection, and a second marker under a constitutive promoter independent of HIV promoter activity. Infection of cells with these viruses allows the identification and separation of latently-infected cells from uninfected and productively infected cells. These reporters are sufficiently sensitive and robust for high-throughput screening to identify drugs that reactivate latent HIV. These reporters can be used in primary CD4 T lymphocytes and reveal a rare population of latently infected cells responsive to physiological stimuli. In summary, our HIV-1 reporters enable visualization and purification of latent cell populations and open up new perspectives for studies of latent HIV infection. PMID:24074592

  3. Dual-color HIV reporters trace a population of latently infected cells and enable their purification.

    PubMed

    Calvanese, Vincenzo; Chavez, Leonard; Laurent, Timothy; Ding, Sheng; Verdin, Eric

    2013-11-01

    HIV latency constitutes the main barrier for clearing HIV infection from patients. Our inability to recognize and isolate latently infected cells hinders the study of latent HIV. We engineered two HIV-based viral reporters expressing different fluorescent markers: one HIV promoter-dependent marker for productive HIV infection, and a second marker under a constitutive promoter independent of HIV promoter activity. Infection of cells with these viruses allows the identification and separation of latently infected cells from uninfected and productively infected cells. These reporters are sufficiently sensitive and robust for high-throughput screening to identify drugs that reactivate latent HIV. These reporters can be used in primary CD4 T lymphocytes and reveal a rare population of latently infected cells responsive to physiological stimuli. In summary, our HIV-1 reporters enable visualization and purification of latent-cell populations and open up new perspectives for studies of latent HIV infection.

  4. HIV–1 Infects Multipotent Progenitor Cells Causing Cell Death and Establishing Latent Cellular Reservoirs

    PubMed Central

    Carter, Christoph C.; Onafuwa–Nuga, Adewunmi; McNamara, Lucy A.; Riddell, James; Bixby, Dale; Savona, Michael R.; Collins, Kathleen L.

    2010-01-01

    HIV causes a chronic infection characterized by depletion of CD4+ T lymphocytes and development of opportunistic infections. Despite drugs that inhibit viral spread, HIV has been difficult to cure because of uncharacterized reservoirs of infected cells that are resistant to highly active antiretroviral therapy and the immune response. Here we used CD34+ cells from infected people as well as in vitro studies of wild type HIV to demonstrate infection and killing of CD34+ multipotent hematopoietic progenitor cells (HPCs). In some HPCs, we detected latent infection that stably persisted in cell culture until viral gene expression was activated by differentiation factors. A novel reporter HIV that directly detects latently infected cells in vitro confirmed the presence of distinct populations of active and latently infected HPCs. These findings have important implications for understanding HIV bone marrow pathology and the mechanisms by which HIV causes persistent infection. PMID:20208541

  5. IFITM1 targets HIV-1 latently infected cells for antibody-dependent cytolysis

    PubMed Central

    Raposo, Rui André Saraiva; de Mulder Rougvie, Miguel; Brailey, Phillip M.; Cabido, Vinicius D.; Zdinak, Paul M.; Thomas, Allison S.; Beckerle, Greta A.; Jones, Richard B.; Nixon, Douglas F.

    2017-01-01

    HIV-1 persistence in latent reservoirs during antiretroviral therapy (ART) is the main obstacle to virus eradication. To date, there is no marker that adequately identifies latently infected CD4+ T cells in vivo. Using a well-established ex vivo model, we generated latently infected CD4+ T cells and identified interferon-induced transmembrane protein 1 (IFITM1), a transmembrane antiviral factor, as being overexpressed in latently infected cells. By targeting IFITM1, we showed the efficient and specific killing of a latently infected cell line and CD4+ T cells from ART-suppressed patients through antibody-dependent cytolysis. We hypothesize that IFITM1 could mark natural reservoirs, identifying an immune target for killing of latently infected cells. These novel insights could be explored to develop clinical therapeutic approaches to effectively eradicate HIV-1. PMID:28097226

  6. 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

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

    PubMed

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

    2015-10-01

    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.

  8. Latent KSHV Infected Endothelial Cells Are Glutamine Addicted and Require Glutaminolysis for Survival

    PubMed Central

    Sanchez, Erica L.; Carroll, Patrick A.; Thalhofer, Angel B.; Lagunoff, Michael

    2015-01-01

    Kaposi’s Sarcoma-associated Herpesvirus (KSHV) is the etiologic agent of Kaposi’s Sarcoma (KS). KSHV establishes a predominantly latent infection in the main KS tumor cell type, the spindle cell, which is of endothelial cell origin. KSHV requires the induction of multiple metabolic pathways, including glycolysis and fatty acid synthesis, for the survival of latently infected endothelial cells. Here we demonstrate that latent KSHV infection leads to increased levels of intracellular glutamine and enhanced glutamine uptake. Depletion of glutamine from the culture media leads to a significant increase in apoptotic cell death in latently infected endothelial cells, but not in their mock-infected counterparts. In cancer cells, glutamine is often required for glutaminolysis to provide intermediates for the tri-carboxylic acid (TCA) cycle and support for the production of biosynthetic and bioenergetic precursors. In the absence of glutamine, the TCA cycle intermediates alpha-ketoglutarate (αKG) and pyruvate prevent the death of latently infected cells. Targeted drug inhibition of glutaminolysis also induces increased cell death in latently infected cells. KSHV infection of endothelial cells induces protein expression of the glutamine transporter, SLC1A5. Chemical inhibition of SLC1A5, or knockdown by siRNA, leads to similar cell death rates as glutamine deprivation and, similarly, can be rescued by αKG. KSHV also induces expression of the heterodimeric transcription factors c-Myc-Max and related heterodimer MondoA-Mlx. Knockdown of MondoA inhibits expression of both Mlx and SLC1A5 and induces a significant increase in cell death of only cells latently infected with KSHV, again, fully rescued by the supplementation of αKG. Therefore, during latent infection of endothelial cells, KSHV activates and requires the Myc/MondoA-network to upregulate the glutamine transporter, SLC1A5, leading to increased glutamine uptake for glutaminolysis. These findings expand our

  9. Designed transcription activator-like effector proteins efficiently induced the expression of latent HIV-1 in latently infected cells.

    PubMed

    Wang, Xiaohui; Wang, Pengfei; Fu, Zheng; Ji, Haiyan; Qu, Xiying; Zeng, Hanxian; Zhu, Xiaoli; Deng, Junxiao; Lu, Panpan; Zha, Shijun; Song, Zhishuo; Zhu, Huanzhang

    2015-01-01

    HIV latency is the foremost barrier to clearing HIV infection from patients. Reactivation of latent HIV-1 represents a promising strategy to deplete these viral reservoirs. Here, we report a novel approach to reactivate latent HIV-1 provirus using artificially designed transcription activator-like effector (TALE) fusion proteins containing a DNA-binding domain specifically targeting the HIV-1 promoter and the herpes simplex virus-based transcriptional activator VP64 domain. We engineered four TALE genes (TALE1-4) encoding TALE proteins, each specifically targeting different 20-bp DNA sequences within the HIV-1 promoter, and we constructed four TALE-VP64 expression vectors corresponding to TALE1-4. We found that TALE1-VP64 effectively reactivated HIV-1 gene expression in latently infected C11 and A10.6 cells. We further confirmed that TALE1-VP64 reactivated latent HIV-1 via specific binding to the HIV-LTR promoter. Moreover, we also found that TALE1-VP64 did not affect cell proliferation or cell cycle distribution. Taken together, our data demonstrated that TALE1-VP64 can specifically and effectively reactivate latent HIV-1 transcription, suggesting that this strategy may provide a novel approach for anti-HIV-1 latency therapy in the future.

  10. HIV integration sites in latently infected cell lines: evidence of ongoing replication.

    PubMed

    Symons, Jori; Chopra, Abha; Malatinkova, Eva; De Spiegelaere, Ward; Leary, Shay; Cooper, Don; Abana, Chike O; Rhodes, Ajantha; Rezaei, Simin D; Vandekerckhove, Linos; Mallal, Simon; Lewin, Sharon R; Cameron, Paul U

    2017-01-13

    Assessing the location and frequency of HIV integration sites in latently infected cells can potentially inform our understanding of how HIV persists during combination antiretroviral therapy. We developed a novel high throughput sequencing method to evaluate HIV integration sites in latently infected cell lines to determine whether there was virus replication or clonal expansion in these cell lines observed as multiple integration events at the same position. We modified a previously reported method using random DNA shearing and PCR to allow for high throughput robotic processing to identify the site and frequency of HIV integration in latently infected cell lines. Latently infected cell lines infected with intact virus demonstrated multiple distinct HIV integration sites (28 different sites in U1, 110 in ACH-2 and 117 in J1.1 per 150,000 cells). In contrast, cell lines infected with replication-incompetent viruses (J-Lat cells) demonstrated single integration sites. Following in vitro passaging of the ACH-2 cell line, we observed a significant increase in the frequency of unique HIV integration sites and there were multiple mutations and large deletions in the proviral DNA. When the ACH-2 cell line was cultured with the integrase inhibitor raltegravir, there was a significant decrease in the number of unique HIV integration sites and a transient increase in the frequency of 2-LTR circles consistent with virus replication in these cells. Cell lines latently infected with intact HIV demonstrated multiple unique HIV integration sites indicating that these cell lines are not clonal and in the ACH-2 cell line there was evidence of low level virus replication. These findings have implications for the use of latently infected cell lines as models of HIV latency and for the use of these cells as standards.

  11. Proliferation of latently infected CD4+ T cells carrying replication-competent HIV-1: Potential role in latent reservoir dynamics

    PubMed Central

    Hosmane, Nina N.; Kwon, Kyungyoon J.; Bruner, Katherine M.; Capoferri, Adam A.; Rosenbloom, Daniel I.S.; Keele, Brandon F.; Ho, Ya-Chi

    2017-01-01

    A latent reservoir for HIV-1 in resting CD4+ T lymphocytes precludes cure. Mechanisms underlying reservoir stability are unclear. Recent studies suggest an unexpected degree of infected cell proliferation in vivo. T cell activation drives proliferation but also reverses latency, resulting in productive infection that generally leads to cell death. In this study, we show that latently infected cells can proliferate in response to mitogens without producing virus, generating progeny cells that can release infectious virus. Thus, assays relying on one round of activation underestimate reservoir size. Sequencing of independent clonal isolates of replication-competent virus revealed that 57% had env sequences identical to other isolates from the same patient. Identity was confirmed by full-genome sequencing and was not attributable to limited viral diversity. Phylogenetic and statistical analysis suggested that identical sequences arose from in vivo proliferation of infected cells, rather than infection of multiple cells by a dominant viral species. The possibility that much of the reservoir arises by cell proliferation presents challenges to cure. PMID:28341641

  12. Proliferation of latently infected CD4(+) T cells carrying replication-competent HIV-1: Potential role in latent reservoir dynamics.

    PubMed

    Hosmane, Nina N; Kwon, Kyungyoon J; Bruner, Katherine M; Capoferri, Adam A; Beg, Subul; Rosenbloom, Daniel I S; Keele, Brandon F; Ho, Ya-Chi; Siliciano, Janet D; Siliciano, Robert F

    2017-04-03

    A latent reservoir for HIV-1 in resting CD4(+) T lymphocytes precludes cure. Mechanisms underlying reservoir stability are unclear. Recent studies suggest an unexpected degree of infected cell proliferation in vivo. T cell activation drives proliferation but also reverses latency, resulting in productive infection that generally leads to cell death. In this study, we show that latently infected cells can proliferate in response to mitogens without producing virus, generating progeny cells that can release infectious virus. Thus, assays relying on one round of activation underestimate reservoir size. Sequencing of independent clonal isolates of replication-competent virus revealed that 57% had env sequences identical to other isolates from the same patient. Identity was confirmed by full-genome sequencing and was not attributable to limited viral diversity. Phylogenetic and statistical analysis suggested that identical sequences arose from in vivo proliferation of infected cells, rather than infection of multiple cells by a dominant viral species. The possibility that much of the reservoir arises by cell proliferation presents challenges to cure.

  13. Short Communication: Preferential Killing of HIV Latently Infected CD4(+) T Cells by MALT1 Inhibitor.

    PubMed

    Li, Hongmei; He, Hui; Gong, Leyi; Fu, Mingui; Wang, Tony T

    2016-02-01

    We report that the addition of an host paracaspase MALT1 inhibitor, MI-2, to HIV latently infected ACH-2, Jurkat E4, and J-LAT cells accelerated cell death in the presence of cell stimuli or the protein kinase C agonist, bryostatin 1. MI-2-mediated cell death correlated with the induction of the cellular RNase MCPIP1 and requires the presence of viral component(s). Altogether, the combination of MI-2 and bryostatin 1 displays selective killing of HIV latently infected CD4(+) T cells.

  14. Short Communication: Preferential Killing of HIV Latently Infected CD4+ T Cells by MALT1 Inhibitor

    PubMed Central

    Li, Hongmei; He, Hui; Gong, Leyi; Fu, Mingui

    2016-01-01

    Abstract We report that the addition of an host paracaspase MALT1 inhibitor, MI-2, to HIV latently infected ACH-2, Jurkat E4, and J-LAT cells accelerated cell death in the presence of cell stimuli or the protein kinase C agonist, bryostatin 1. MI-2-mediated cell death correlated with the induction of the cellular RNase MCPIP1 and requires the presence of viral component(s). Altogether, the combination of MI-2 and bryostatin 1 displays selective killing of HIV latently infected CD4+ T cells. PMID:26728103

  15. Selective retention of herpes simplex virus-specific T cells in latently infected human trigeminal ganglia

    PubMed Central

    Verjans, Georges M. G. M.; Hintzen, Rogier Q.; van Dun, Jessica M.; Poot, Angelique; Milikan, Johannes C.; Laman, Jon D.; Langerak, Anton W.; Kinchington, Paul R.; Osterhaus, Albert D. M. E.

    2007-01-01

    Primary infection with herpes simplex virus 1 (HSV-1) and varicella zoster virus (VZV) results in lifelong latent infections of neurons in sensory ganglia such as the trigeminal ganglia (TG). It has been postulated that T cells retained in TG inhibit reactivation of latent virus. The acquisition of TG specimens of individuals within hours after death offered the unique opportunity to characterize the phenotype and specificity of TG-resident T cells in humans. High numbers of activated CD8+ T cells expressing a late effector memory phenotype were found to reside in latently infected TG. The T cell infiltrate was oligoclonal, and T cells selectively clustered around HSV-1 but not VZV latently infected neurons. Neuronal damage was not observed despite granzyme B expression by the neuron-interacting CD8+ T cells. The TG-resident T cells, mainly CD8+ T cells, were directed against HSV-1 and not to VZV, despite neuronal expression of VZV proteins. The results implicate that herpesvirus latency in human TG is associated with a local, persistent T cell response, comprising activated late effector memory CD8+ T cells that appear to control HSV-1 latency by noncytolytic pathways. In contrast, T cells do not seem to be directly involved in controlling VZV latency in human TG. PMID:17360672

  16. Application of a nanoflare probe specific to a latency associated transcript for isolation of KHV latently infected cells

    PubMed Central

    Reed, Aimee N.; Putman, Timothy; Sullivan, Christopher; Jin, Ling

    2015-01-01

    One of the unique features of herpesvirus infection is latent infection following an initial exposure, which is characterized by viral genome persistence in a small fraction of cells within the latently infected tissue. Investigation of the mechanisms of herpesvirus latency has been very challenging in tissues with only a small fraction of cells that are latently infected. Cyprinid herpesvirus 3, also known as koi herpesvirus (KHV), is an important and deadly pathogen of koi and common carp, Cyprinus carpio. Acute infection can cause up to 100% mortality in exposed fish, and fish that survive the infection become latently infected. KHV becomes latent in a small percentage of B lymphocytes and can reactivate under stressful conditions. During latency, KHV ORF6 transcript is expressed in the latently infected B lymphocytes. In order to study KHV latent infection in cells that are only latently infected, a nanoflare probe specific to ORF6 RNA was used to separate KHV latently infected cells from total peripheral white blood cells (WBC). Using the ORF6 nanoflare probe, less than 1% of peripheral WBC was isolated from KHV latently infected koi. When this enriched population of WBC was examined by real-time PCR specific for KHV, it was estimated that about 1 to 2 copies of viral genome persists in the sorted cells. In addition, KHV ORF6 transcript was shown to be the major transcript expressed during latency by RNA-seq analysis. This study demonstrated that an RNA nanoflare probe could be used to enrich latently infected cells, which can subsequently be used to investigate the molecular mechanisms of KHV latency. PMID:26087404

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

    PubMed

    Liang, Xiaozhen; Collins, Christopher M; Mendel, Justin B; Iwakoshi, Neal N; Speck, Samuel H

    2009-11-01

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

  18. Endothelial Cell Stimulation Overcomes Restriction and Promotes Productive and Latent HIV-1 Infection of Resting CD4+ T Cells

    PubMed Central

    Baker, Jacob J.; Scott, Geoffrey L.; Davis, Yelena P.; Ho, Yen-Yi; Siliciano, Robert F.

    2013-01-01

    Highly active antiretroviral therapy (HAART) is able to suppress human immunodeficiency virus type 1 (HIV-1) to undetectable levels in the majority of patients, but eradication has not been achieved because latent viral reservoirs persist, particularly in resting CD4+ T lymphocytes. It is generally understood that HIV-1 does not efficiently infect resting CD4+ T cells, and latent infection in those cells may arise when infected CD4+ T lymphoblasts return to resting state. In this study, we found that stimulation by endothelial cells can render resting CD4+ T cells permissible for direct HIV infection, including both productive and latent infection. These stimulated T cells remain largely phenotypically unactivated and show a lower death rate than activated T cells, which promotes the survival of infected cells. The stimulation by endothelial cells does not involve interleukin 7 (IL-7), IL-15, CCL19, or CCL21. Endothelial cells line the lymphatic vessels in the lymphoid tissues and have frequent interactions with T cells in vivo. Our study proposes a new mechanism for infection of resting CD4+ T cells in vivo and a new mechanism for latent infection in resting CD4+ T cells. PMID:23824795

  19. Cytomegalovirus causes a latent infection in undifferentiated cells and is activated by induction of cell differentiation

    PubMed Central

    Dutko, FJ; Oldstone, MBA

    1981-01-01

    Murine cytomegalovirus (MCMV) does not productively infect OTT6050AF1 BrdU, F9, or PCC4 undifferentiated murine teratocarcinoma cell lines, as shown by immunofluorescence assays for viral antigens and by plaque assays for infectious virus. However, these cells were infected by a variety of other viruses. MCMV does productively infect PYS2 and OTT F12 differentiated murine teratocarcinoma cell lines. The replication of MCMV in the pluripotent PCC4 cell line was examined in detail. Undifferentiated PCC4 cells could be differentiated when propagated in the presence of dimethylacetamide, as judged by changes in the expression of H-2 antigens on the cell surface. Several viruses, including lymphocytic choriomeningitis virus, herpes simplex virus type 1, and vesicular stomatitis virus, replicated to a similar extent in differentiated and undifferentiated PCC4 cells. MCMV did productively infect differentiated PCC4 cells. In contrast, MCMV did not produce infectious virus, viral antigens, or substantial viral RNA in undifferentiated PCC4 cells. The molecular block of MCMV replication occurred at the level of MCMV RNA transcription. Undifferentiated PCC4 cells have receptors for MCMV and bind similar amounts of radiolabeled virus as differentiated PCC4 cells. After MCMV binds to its receptors on undifferentiated cells, MCMV penetrates the plasma membrane and is transported to the cells' nuclei. MCMV DNA was present in the cytoplasm, and small amounts of MCMV RNA (less than 17 percent of that found in MCMV-infected differentiated PCC4 cells) were found in the nucleus. However, MCMV RNA was not detected in the cytoplasm of undifferentiated cells. A latent infection was established by infecting undifferentiated PCC4 cells with MCMV, inactivating residual infectivity with antibodies to MCMV, and propagating cells under conditions that maintained the undifferentiated state. These MCMV-infected undifferentiated cells did not produce infectious virus, viral antigens, or viral RNA

  20. Expression of herpes simplex virus 1 microRNAs in cell culture models of quiescent and latent infection.

    PubMed

    Jurak, Igor; Hackenberg, Michael; Kim, Ju Youn; Pesola, Jean M; Everett, Roger D; Preston, Chris M; Wilson, Angus C; Coen, Donald M

    2014-02-01

    To facilitate studies of herpes simplex virus 1 latency, cell culture models of quiescent or latent infection have been developed. Using deep sequencing, we analyzed the expression of viral microRNAs (miRNAs) in two models employing human fibroblasts and one using rat neurons. In all cases, the expression patterns differed from that in productively infected cells, with the rat neuron pattern most closely resembling that found in latently infected human or mouse ganglia in vivo.

  1. LATENT VIRAL INFECTION OF CELLS IN TISSUE CULTURE

    PubMed Central

    Bader, John P.; Morgan, Herbert R.

    1961-01-01

    A study of the metabolic requirements for the growth of psittacosis virus in L cells has been extended to the water-soluble vitamins. In a system in which a balanced salt solution was used to deplete the cells of their vitamin constituents, only thiamine was essential for psittacosis virus production. Extended depletion of cells with media deficient in specific vitamins demonstrated that pantothenate, niacin (niacinamide), pyridoxine (pyridoxal), and choline, in addition to thiamine, were essential for maximal growth of psittacosis virus. No requirement for biotin, inositol, folic acid, or riboflavin was demonstrated, although the possibility of incomplete vitamin depletion of the cells has not been eliminated. In most cases in which a specific vitamin requirement was shown the decreased yield of virus was correlated with a delay in the cytopathic effects produced in the cell cultures by psittacosis virus. PMID:13685754

  2. Psychological stress compromises CD8+ T cell control of latent herpes simplex virus type 1 infections.

    PubMed

    Freeman, Michael L; Sheridan, Brian S; Bonneau, Robert H; Hendricks, Robert L

    2007-07-01

    Recurrent HSV-1 ocular disease results from reactivation of latent virus in trigeminal ganglia, often following immunosuppression or exposure to a variety of psychological or physical stressors. HSV-specific CD8+ T cells can block HSV-1 reactivation from latency in ex vivo trigeminal ganglia cultures through production of IFN-gamma. In this study, we establish that either CD8+ T cell depletion or exposure to restraint stress permit HSV-1 to transiently escape from latency in vivo. Restraint stress caused a reduction of TG-resident HSV-specific CD8+ T cells and a functional compromise of those cells that survive. Together, these effects of stress resulted in an approximate 65% reduction of cells capable of producing IFN-gamma in response to reactivating virus. Our findings demonstrate persistent in vivo regulation of latent HSV-1 by CD8+ T cells, and strongly support the concept that stress induces HSV-1 reactivation from latency at least in part by compromising CD8+ T cell surveillance of latently infected neurons.

  3. 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.

  4. 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

  5. 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.

  6. 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.

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

    PubMed Central

    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

  8. Soluble Factors Secreted by Endothelial Cells Allow for Productive and Latent HIV-1 Infection in Resting CD4(+) T Cells.

    PubMed

    Morris, John Henry; Nguyen, Tran; Nwadike, Abuoma; Geels, Mackenzie L; Kamp, Derrick L; Kim, Bo Ram; Boyer, Jean D; Shen, Anding

    2017-02-01

    In vitro, it is difficult to infect resting CD4(+) T cells with human immunodeficiency virus type 1 (HIV), but infections readily occur in vivo. Endothelial cells (ECs) interact with resting CD4(+) T cells in vivo, and we found previously that EC stimulation leads to productive and latent HIV infection of resting CD4(+) T cells. In this study, we further characterize the interactions between EC and resting T cells. We found that resting CD4(+) T cells did not require direct contact with EC for productive and/or latent infection to occur, indicating the involvement of soluble factors. Among 30 cytokines tested in a multiplex enzyme-linked immunosorbent assay (ELISA), we found that expressions for IL-6, IL-8, and CCL2 were much higher in EC-stimulated resting T cells than resting T cells cultured alone. IL-6 was found to be the soluble factor responsible for inducing productive infection of resting T cells, although direct contact with EC had an added effect. However, none of the cytokines tested, IL-6, IL-8, or CCL2, induced additional latent infection in resting T cells, suggesting that unidentified cytokines were involved. Intracellular molecules MURR1, c-Jun N-terminal kinase (JNK), and glucose transporter-1 (GLUT1) were previously shown in blocking HIV infection of resting CD4(+) T cells. We found that the concentrations of these proteins were not significantly different in resting T cells before and after stimulation by EC; therefore, they are not likely involved in EC stimulation of resting CD4(+) T cells, and a new mechanism is yet to be identified.

  9. Induction of chemokine production by latent Kaposi's sarcoma-associated herpesvirus infection of endothelial cells.

    PubMed

    Xu, Yiyiang; Ganem, Don

    2007-01-01

    Infection with Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) is linked strongly to development of KS, an endothelial neoplasm also characterized by striking neoangiogenesis and infiltration with inflammatory cells. To elucidate the links between endothelial infection and inflammation, primary human umbilical vein endothelial cells (HUVECs) were examined for the production of chemokines following latent KSHV infection. Several chemokines that are produced in the ground state, including MCP-1, NAP 2 and RANTES, are upregulated significantly by KSHV infection. Moreover, the chemokine CXCL16, which is nearly absent in uninfected cells, is induced significantly following infection. This induction is attributable primarily to expression of vFLIP, a known inducer of NF-kappaB. CXCL16 induces the chemotaxis of activated T cells, whose products have been proposed to positively regulate KS tumour-cell survival and growth. Whilst CXCL16 has also been proposed as a direct endothelial chemoattractant and mitogen, neither proliferation nor chemotaxis of HUVECs was observed following CXCL16 exposure. These results suggest that CXCL16 induction by KSHV contributes to the inflammatory phenotype of KS, but plays little role in the recruitment of endothelial spindle cells.

  10. Human Cytomegalovirus US28 Is Important for Latent Infection of Hematopoietic Progenitor Cells

    PubMed Central

    Humby, Monica S.

    2015-01-01

    ABSTRACT Human cytomegalovirus (HCMV) resides latently in hematopoietic progenitor cells (HPCs). During latency, only a subset of HCMV genes is transcribed, including one of the four virus-encoded G protein-coupled receptors (GPCRs), US28. Although US28 is a multifunctional lytic protein, its function during latency has remained undefined. We generated a panel of US28 recombinant viruses in the bacterial artificial chromosome (BAC)-derived clinical HCMV strain TB40/E-mCherry. We deleted the entire US28 open reading frame (ORF), deleted all four of the viral GPCR ORFs, or deleted three of the HCMV GPCRs but not the US28 wild-type protein. Using these recombinant viruses, we assessed the requirement for US28 during latency in the Kasumi-3 in vitro latency model system and in primary ex vivo-cultured CD34+ HPCs. Our data suggest that US28 is required for latency as infection with viruses lacking the US28 ORF alone or in combination with the remaining HCMV-encoded GPCR results in transcription from the major immediate early promoter, the production of extracellular virions, and the production of infectious virus capable of infecting naive fibroblasts. The other HCMV GPCRs are not required for this phenotype as a virus expressing only US28 but not the remaining virus-encoded GPCRs is phenotypically similar to that of wild-type latent infection. Finally, we found that US28 copurifies with mature virions and is expressed in HPCs upon virus entry although its expression at the time of infection does not complement the US28 deletion latency phenotype. This work suggests that US28 protein functions to promote a latent state within hematopoietic progenitor cells. IMPORTANCE Human cytomegalovirus (HCMV) is a widespread pathogen that, once acquired, remains with its host for life. HCMV remains latent, or quiescent, in cells of the hematopoietic compartment and upon immune challenge can reactivate to cause disease. HCMV-encoded US28 is one of several genes expressed during

  11. Impaired Cytokine but Enhanced Cytotoxic Marker Expression in Mycobacterium tuberculosis-Induced CD8+ T Cells in Individuals With Type 2 Diabetes and Latent Mycobacterium tuberculosis Infection.

    PubMed

    Kumar, Nathella Pavan; Moideen, Kadar; George, Parakkal Jovvian; Dolla, Chandrakumar; Kumaran, Paul; Babu, Subash

    2016-03-01

    Type 2 diabetes mellitus (DM) is a risk factor for tuberculosis among individuals with latent Mycobacterium tuberculosis infection. To explore the influence of DM on CD8(+) T-cell responses during latent M. tuberculosis infection, we estimated the cytokine and cytotoxic marker expression pattern in individuals with latent M. tuberculosis infection with DM and those with latent M. tuberculosis infection without DM. Among individuals with latent M. tuberculosis infection, those with DM had diminished frequencies of CD8(+) T-helper type 1 (Th1), Th2, and Th17 cells following stimulation by M. tuberculosis antigen and enhanced frequencies of CD8(+) T cells expressing cytotoxic markers, compared with those without DM. Thus, our results suggest that coincident DM modulates CD8(+) T-cell function during latent M. tuberculosis infection.

  12. Infected Peripheral Blood Mononuclear Cells Transmit Latent Varicella Zoster Virus Infection to the Guinea Pig Enteric Nervous System

    PubMed Central

    Gan, Lin; Wang, Mingli; Chen, Jason J.; Gershon, Michael D.; Gershon, Anne A.

    2014-01-01

    Latent wild-type (WT) and vaccine (vOka) varicella-zoster virus (VZV) are found in the human enteric nervous system (ENS). VZV also infects guinea pig enteric neurons in vitro, establishes latency and can be reactivated. We therefore determined whether lymphocytes infected in vitro with VZV secrete infectious virions and can transfer infection in vivo to the ENS of recipient guinea pigs. T lymphocytes (CD3-immunoreactive) were preferentially infected following co-culture of guinea pig or human peripheral blood mononuclear cells with VZV-infected HELF. VZV proliferated in the infected T cells and expressed immediate early and late VZV genes. Electron microscopy confirmed that VZV-infected T cells produced encapsulated virions. Extracellular virus, however, was pleomorphic, suggesting degradation occurred prior to release, which was confirmed by the failure of VZV-infected T cells to secrete infectious virions. Intravenous injection of WT- or vOka-infected PBMCs, nevertheless, transmitted VZV to recipient animals (guinea pig > human lymphocytes). Two days post-inoculation, lung and liver, but not gut, contained DNA and transcripts encoding ORFs 4, 40, 66 and 67. Twenty-eight days after infection, gut contained DNA and transcripts encoding ORFs 4 and 66 but neither DNA nor transcripts could any longer be found in lung or liver. In situ hybridization revealed VZV DNA in enteric neurons, which also expressed ORF63p (but not ORF68p) immunoreactivity. Observations suggest that VZV infects T cells, which can transfer VZV to and establish latency in enteric neurons in vivo. Guinea pigs may be useful for studies of VZV pathogenesis in the ENS. PMID:24965252

  13. Infected peripheral blood mononuclear cells transmit latent varicella zoster virus infection to the guinea pig enteric nervous system.

    PubMed

    Gan, Lin; Wang, Mingli; Chen, Jason J; Gershon, Michael D; Gershon, Anne A

    2014-10-01

    Latent wild-type (WT) and vaccine (vOka) varicella zoster virus (VZV) are found in the human enteric nervous system (ENS). VZV also infects guinea pig enteric neurons in vitro, establishes latency and can be reactivated. We therefore determined whether lymphocytes infected in vitro with VZV secrete infectious virions and can transfer infection in vivo to the ENS of recipient guinea pigs. T lymphocytes (CD3-immunoreactive) were preferentially infected following co-culture of guinea pig or human peripheral blood mononuclear cells with VZV-infected HELF. VZV proliferated in the infected T cells and expressed immediate early and late VZV genes. Electron microscopy confirmed that VZV-infected T cells produced encapsulated virions. Extracellular virus, however, was pleomorphic, suggesting degradation occurred prior to release, which was confirmed by the failure of VZV-infected T cells to secrete infectious virions. Intravenous injection of WT- or vOka-infected PBMCs, nevertheless, transmitted VZV to recipient animals (guinea pig > human lymphocytes). Two days post-inoculation, lung and liver, but not gut, contained DNA and transcripts encoding ORFs 4, 40, 66 and 67. Twenty-eight days after infection, gut contained DNA and transcripts encoding ORFs 4 and 66 but neither DNA nor transcripts could any longer be found in lung or liver. In situ hybridization revealed VZV DNA in enteric neurons, which also expressed ORF63p (but not ORF68p) immunoreactivity. Observations suggest that VZV infects T cells, which can transfer VZV to and establish latency in enteric neurons in vivo. Guinea pigs may be useful for studies of VZV pathogenesis in the ENS.

  14. Control of human cytomegalovirus gene expression by differential histone modifications during lytic and latent infection of a monocytic cell line.

    PubMed

    Ioudinkova, Elena; Arcangeletti, Maria Cristina; Rynditch, Alla; De Conto, Flora; Motta, Federica; Covan, Silvia; Pinardi, Federica; Razin, Sergey V; Chezzi, Carlo

    2006-12-15

    Non-differentiated THP-1 cells can be infected by human cytomegalovirus (HCMV) Towne strain, which persists in these cells in a non-active (latent) form without undergoing a productive cycle. The same cells become permissive for HCMV lytic infection after induction of cell differentiation by treatment with 12-O-tetradecanoylphorbol-13-acetate. We used this cellular model to study the possible role of histone modifications in the control of HCMV latency. Using chromatin immunoprecipitation with antibodies against histone H3 acetylated or dimethylated in position K9, we demonstrated that in lytically infected cells the HCMV enhancer was associated with heavy acetylated but not dimethylated H3. In the case of latent infection, the HCMV enhancer was associated with neither acetylated nor dimethylated H3. HCMV genes encoding DNA polymerase (early), pp65 (early-late) and pp150 (late) proteins were associated preferentially with acetylated H3 in lytically infected cells and with dimethylated H3 in latently infected cells. These data strongly suggest that K9 methylation of H3 is involved in HCMV gene repression, while association of the above genes with acetylated histones is likely to be necessary for active transcription. It can be postulated that the same histone modifications are used to mark active and repressed genes in both cellular and viral chromatin.

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

    PubMed

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

    2015-07-01

    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. 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 form the

  16. FISHing Out the Hidden Enemy: Advances in Detecting and Measuring Latent HIV-Infected Cells.

    PubMed

    Prasad, Vinayaka R; Kalpana, Ganjam V

    2017-09-19

    The indomitable aspect of HIV-1 infection is not that HIV-1 proviral DNA is integrated into host DNA but that it can also turn itself off, remaining invisible to drug or immune surveillance. Thus, the goals of eradication include ways to precisely excise HIV-1 DNA or wake up the silent HIV-1 provirus and eliminate the infected cells thus identified. Methods to identify and fish out the latently infected cells or to delineate their characteristics are being rapidly developed. In 2016, Baxter et al. (A. E. Baxter, J. Niessl, R. Fromentin, J. Richard, F. Porichis, R. Charlebois, M. Massanella, N. Brassard, N. Alsahafi, G. G. Delgado, J. P. Routy, B. D. Walker, A. Finzi, N. Chomont, and D. E. Kaufmann, Cell Host Microbe 20:368-380, 2016, https://doi.org/10.1016/j.chom.2016.07.015) and Martrus et al. (G. Martrus, A. Niehrs, R. Cornelis, A. Rechtien, W. García-Beltran, M. Lütgehetmann, C. Hoffmann, and M. Altfeld, J Virol 90:9018-9028, 2016, https://doi.org/10.1128/JVI.01448-16) reported using the fluorescence in situ hybridization-flow cytometry technique to identify and quantify cells expressing HIV-1 RNA and Gag protein, as well as bearing unique cell surface markers. In a recent article in mBio, Grau-Expósito et al. (J. Grau-Expósito, C. Serra-Peinado, L. Miguel, J. Navarro, A. Curran, J. Burgos, I. Ocaña, E. Ribera, A. Torrella, B. Planas, R. Badía, J. Castellví, V. Falcó, M. Crespo, and M. J. Buzon, mBio 8:e00876-17, 2017, https://doi.org/10.1128/mBio.00876-17) reported a similar method that they claim to be more sensitive. With these methods, researchers are one step closer to measuring latent reservoirs and eliminating critical barriers to HIV eradication. Copyright © 2017 Prasad and Kalpana.

  17. EBNA1-specific luminescent small molecules for the imaging and inhibition of latent EBV-infected tumor cells.

    PubMed

    Jiang, Lijun; Lui, Yin-Lai; Li, Hongguang; Chan, Chi-Fai; Lan, Rongfeng; Chan, Wai-Lun; Lau, Terrence Chi-Kong; Tsao, George Sai-Wah; Mak, Nak-Ki; Wong, Ka-Leung

    2014-06-21

    An EBNA1-specific small molecule (JLP2) has been synthesised. As a strong binder and dimerization inhibitor of EBNA1 in vitro, JLP2 may be used as a selective luminescent agent for the imaging and inhibition of latent EBV-infected cancer cells.

  18. Unsupervised learning techniques reveal heterogeneity in memory CD8(+) T cell differentiation following acute, chronic and latent viral infections.

    PubMed

    Liu, Mingyong; Barton, Erik S; Jennings, Ryan N; Oldenburg, Darby G; Whirry, Juliann M; White, Douglas W; Grayson, Jason M

    2017-09-01

    CD8(+) T lymphocytes are critical for the control of gammaherpesvirus latency. To determine how memory CD8(+) T cells generated during latency differ from those primed during acute or chronic viral infection, we adoptively transferred naive P14 CD8(+) T cells into uninfected recipients, and examined surface proteins, cytokines and transcription factors following infection with the Armstrong (acute) or Clone 13 (chronic) strains of lymphocytic choriomeningitis virus (LCMV), or murine gammaherpesvirus 68 (MHV68) expressing the LCMV epitope D(b)GP33-41. By performing k-means clustering and generating self organizing maps (SOM), we observed increased short-lived effector-like, CD27(l)(o) CD62L(l)(o) and Bcl-6(l)(o) CD8(+) T cells following latent infection. In addition, we found that memory CD8(+) T cells from latent primed mice underwent less expansion following adoptive transfer and antigen rechallenge. Data from cluster models were combined and visualized by principal component analysis (PCA) demonstrating memory CD8(+) T cells from latent infection occupy an intermediate differentiation space. Copyright © 2017. Published by Elsevier Inc.

  19. Gastric carcinoma: monoclonal epithelial malignant cells expressing Epstein-Barr virus latent infection protein.

    PubMed Central

    Imai, S; Koizumi, S; Sugiura, M; Tokunaga, M; Uemura, Y; Yamamoto, N; Tanaka, S; Sato, E; Osato, T

    1994-01-01

    In 1000 primary gastric carcinomas, 70 (7.0%) contained Epstein-Barr virus (EBV) genomic sequences detected by PCR and Southern blots. The positive tumors comprised 8 of 9 (89%) undifferentiated lymphoepithelioma-like carcinomas, 27 of 476 (5.7%) poorly differentiated adenocarcinomas, and 35 of 515 (6.8%) moderately to well-differentiated adenocarcinomas. In situ EBV-encoded small RNA 1 hybridization and hematoxylin/eosin staining in adjacent sections showed that the EBV was present in every carcinoma cell but was not significantly present in lymphoid stroma and in normal mucosa. Two-color immunofluorescence and hematoxylin/eosin staining in parallel sections revealed that every keratin-positive epithelial malignant cell expressed EBV-determined nuclear antigen 1 (EBNA1) but did not significantly express CD45+ infiltrating leukocytes. A single fused terminal fragment was detected in each of the EBNA1-expressing tumors, thereby suggesting that the EBV-carrying gastric carcinomas represent clonal proliferation of cells infected with EBV. The carcinoma cells had exclusively EBNA1 but not EBNA2, -3A, -3B, and -3C; leader protein; and latent membrane protein 1 because of methylation. The patients with EBV-carrying gastric carcinoma had elevated serum EBV-specific antibodies. The EBV-specific cellular immunity was not significantly reduced; however, the cytotoxic T-cell target antigens were not expressed. These findings strongly suggest a causal relation between a significant proportion of gastric carcinoma and EBV, and the virus-carrying carcinoma cells may evade immune surveillance. Images PMID:8090780

  20. Stochastic modelling of the eradication of the HIV-1 infection by stimulation of latently infected cells in patients under highly active anti-retroviral therapy.

    PubMed

    Sánchez-Taltavull, Daniel; Vieiro, Arturo; Alarcón, Tomás

    2016-10-01

    HIV-1 infected patients are effectively treated with highly active anti-retroviral therapy (HAART). Whilst HAART is successful in keeping the disease at bay with average levels of viral load well below the detection threshold of standard clinical assays, it fails to completely eradicate the infection, which persists due to the emergence of a latent reservoir with a half-life time of years and is immune to HAART. This implies that life-long administration of HAART is, at the moment, necessary for HIV-1-infected patients, which is prone to drug resistance and cumulative side effects as well as imposing a considerable financial burden on developing countries, those more afflicted by HIV, and public health systems. The development of therapies which specifically aim at the removal of this latent reservoir has become a focus of much research. A proposal for such therapy consists of elevating the rate of activation of the latently infected cells: by transferring cells from the latently infected reservoir to the active infected compartment, more cells are exposed to the anti-retroviral drugs thus increasing their effectiveness. In this paper, we present a stochastic model of the dynamics of the HIV-1 infection and study the effect of the rate of latently infected cell activation on the average extinction time of the infection. By analysing the model by means of an asymptotic approximation using the semi-classical quasi steady state approximation (QSS), we ascertain that this therapy reduces the average life-time of the infection by many orders of magnitudes. We test the accuracy of our asymptotic results by means of direct simulation of the stochastic process using a hybrid multi-scale Monte Carlo scheme.

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

    PubMed

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

    2014-07-31

    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. The HIV-1 latency cell lines (NCHA1, NCHA2 and ACH2] were compared with CD4⁺ T-cell line (A3.01). 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. 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. 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.

  2. Tuberculosis Infection and Latent Tuberculosis

    PubMed Central

    2016-01-01

    Active tuberculosis (TB) has a greater burden of TB bacilli than latent TB and acts as an infection source for contacts. Latent tuberculosis infection (LTBI) is the state in which humans are infected with Mycobacterium tuberculosis without any clinical symptoms, radiological abnormality, or microbiological evidence. TB is transmissible by respiratory droplet nucleus of 1–5 µm in diameter, containing 1–10 TB bacilli. TB transmission is affected by the strength of the infectious source, infectiousness of TB bacilli, immunoresistance of the host, environmental stresses, and biosocial factors. Infection controls to reduce TB transmission consist of managerial activities, administrative control, engineering control, environmental control, and personal protective equipment provision. However, diagnosis and treatment for LTBI as a national TB control program is an important strategy on the precondition that active TB is not missed. Therefore, more concrete evidences for LTBI management based on clinical and public perspectives are needed. PMID:27790271

  3. Modulation of mycobacterial-specific Th1 and Th17 cells in latent tuberculosis by coincident hookworm infection.

    PubMed

    George, Parakkal Jovvian; Anuradha, Rajamanickam; Kumaran, Paramasivam Paul; Chandrasekaran, Vedachalam; Nutman, Thomas B; Babu, Subash

    2013-05-15

    Hookworm infections and tuberculosis (TB) are coendemic in many parts of the world. It has been suggested that infection with helminth parasites could suppress the predominant Th1 (IFN-γ-mediated) response needed to control Mycobacterium tuberculosis infection and enhance susceptibility to infection and/or disease. To determine the role of coincident hookworm infection on responses at steady-state and on M. tuberculosis-specific immune responses in latent TB (LTB), we examined the cellular responses in individuals with LTB with or without concomitant hookworm infection. By analyzing the expression of Th1, Th2, and Th17 subsets of CD4(+) T cells, we were able to demonstrate that the presence of coincident hookworm infection significantly diminished both spontaneously expressed and M. tuberculosis-specific mono- and dual-functional Th1 and Th17 cells. Hookworm infection, in contrast, was associated with expanded frequencies of mono- and dual-functional Th2 cells at both steady-state and upon Ag stimulation. This differential induction of CD4(+) T cell subsets was abrogated upon mitogen stimulation. Additionally, coincident hookworm infection was associated with increased adaptive T regulatory cells but not natural regulatory T cells in LTB. Finally, the CD4(+) T cell cytokine expression pattern was also associated with alterations in the systemic levels of Th1 and Th2 cytokines. Thus, coincident hookworm infection exerts a profound inhibitory effect on protective Th1 and Th17 responses in LTB and may predispose toward the development of active tuberculosis in humans.

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

    PubMed Central

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

    2016-01-01

    Summary 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. 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. © 2016 British Society for Immunology.

  6. Provirus activation plus CD59 blockage triggers antibody-dependent complement-mediated lysis of latently HIV-1-infected cells.

    PubMed

    Lan, Jie; Yang, Kai; Byrd, Daniel; Hu, Ningjie; Amet, Tohti; Shepherd, Nicole; Desai, Mona; Gao, Jimin; Gupta, Samir; Sun, Yongtao; Yu, Qigui

    2014-10-01

    Latently HIV-1-infected cells are recognized as the last barrier toward viral eradication and cure. To purge these cells, we combined a provirus stimulant with a blocker of human CD59, a key member of the regulators of complement activation, to trigger Ab-dependent complement-mediated lysis. Provirus stimulants including prostratin and histone deacetylase inhibitors such as romidepsin and suberoylanilide hydroxamic acid activated proviruses in the latently HIV-1-infected T cell line ACH-2 as virion production and viral protein expression on the cell surface were induced. Romidepsin was the most attractive provirus stimulant as it effectively activated proviruses at nanomolar concentrations that can be achieved clinically. Antiretroviral drugs including two protease inhibitors (atazanavir and darunavir) and an RT inhibitor (emtricitabine) did not affect the activity of provirus stimulants in the activation of proviruses. However, saquinavir (a protease inhibitor) markedly suppressed virus production, although it did not affect the percentage of cells expressing viral Env on the cell surface. Provirus-activated ACH-2 cells expressed HIV-1 Env that colocalized with CD59 in lipid rafts on the cell surface, facilitating direct interaction between them. Blockage of CD59 rendered provirus-activated ACH-2 cells and primary human CD4(+) T cells that were latently infected with HIV-1 sensitive to Ab-dependent complement-mediated lysis by anti-HIV-1 polyclonal Abs or plasma from HIV-1-infected patients. Therefore, a combination of provirus stimulants with regulators of complement activation blockers represents a novel approach to eliminate HIV-1. Copyright © 2014 by The American Association of Immunologists, Inc.

  7. Entinostat is a histone deacetylase inhibitor selective for class 1 histone deacetylases and activates HIV production from latently infected primary T cells

    PubMed Central

    Wightman, Fiona; Lu, Hao K.; Solomon, Ajantha E.; Saleh, Suha; Harman, Andrew N.; Cunningham, Anthony L.; Gray, Lachlan; Churchill, Melissa; Cameron, Paul U.; Dear, Anthony E.; Lewin, Sharon R.

    2014-01-01

    Objectives To compare the potency, toxicity and mechanism of action of multiple histone deacetylase inhibitors (HDACi) in activating HIV production from latency. Design In-vitro analysis of HDACi in a primary T-cell model of HIV latency and latently infected cell lines. Methods Latently infected chemokine ligand 19 (CCL19)-treated CD4+ T cells and the latently infected cell lines ACH2 and J-Lat were treated with a panel of HDACi, including entinostat, vorinostat, panonbinostat and MCT3. Viral production and cell viability were compared. Expression of cellular HDACs was measured by western blot and PCR. Association of HDACs with the HIV long-terminal repeat (LTR) using latently infected CCL19-treated primary CD4+ T cells in the presence and absence of specific HDACi was determined by chromatin immunoprecipitation (ChIP). Results We demonstrated considerable variation in the potency and toxicity of HDACi in latently infected primary CD4+ T cells and cell lines. All HDACi tested activated HIV production in latently infected primary T cells with greatest potency demonstrated with entinostat and vorinostat and greatest toxicity with panobinostat. Following the addition of HDACi in vitro, there were no changes in markers of T-cell activation or expression of the HIV coreceptors chemokine (C-X-C motif) receptor 4 (CXCR4) or chemokine (C-C motif) receptor type 5 (CCR5). ChIP analysis of latently infected CCL19-treated primary CD4+ T cells showed binding by HDAC1, HDAC2 and HDAC3 to the LTR with removal of HDAC1 and HDAC2 following treatment with the HDACi vorinostat and HDAC1 only following treatment with entinostat. Conclusion The HDACi entinostat, selective for inhibition of class I HDACs, induced virus expression in latently infected primary CD4+ T cells making this compound an attractive novel option for future clinical trials. PMID:24189584

  8. Reactivation Kinetics of HIV-1 and Susceptibility of Reactivated Latently Infected CD4+ T Cells to HIV-1-Specific CD8+ T Cells

    PubMed Central

    Walker-Sperling, Victoria E. K.; Cohen, Valerie J.; Tarwater, Patrick M.

    2015-01-01

    ABSTRACT The “shock and kill” model of human immunodeficiency virus type 1 (HIV-1) eradication involves the induction of transcription of HIV-1 genes in latently infected CD4+ T cells, followed by the elimination of these infected CD4+ T cells by CD8+ T cells or other effector cells. CD8+ T cells may also be needed to control the spread of new infection if residual infected cells are present at the time combination antiretroviral therapy (cART) is discontinued. In order to determine the time frame needed for CD8+ T cells to effectively prevent the spread of HIV-1 infection, we examined the kinetics of HIV transcription and virus release in latently infected cells reactivated ex vivo. Isolated resting, primary CD4+ T cells from HIV-positive (HIV+) subjects on suppressive regimens were found to upregulate cell-associated HIV-1 mRNA within 1 h of stimulation and produce extracellular virus as early as 6 h poststimulation. In spite of the rapid kinetics of virus production, we show that CD8+ T cells from 2 out of 4 viremic controllers were capable of effectively eliminating reactivated autologous CD4+ cells that upregulate cell-associated HIV-1 mRNA. The results have implications for devising strategies to prevent rebound viremia due to reactivation of rare latently infected cells that persist after potentially curative therapy. IMPORTANCE A prominent HIV-1 cure strategy termed “shock and kill” involves the induction of HIV-1 transcription in latently infected CD4+ T cells with the goal of elimination of these cells by either the cytotoxic T lymphocyte response or other immune cell subsets. However, the cytotoxic T cell response may also be required after curative treatment if residual latently infected cells remain. The kinetics of HIV-1 reactivation indicate rapid upregulation of cell-associated HIV-1 mRNA and a 5-h window between transcription and virus release. Thus, HIV-specific CD8+ T cell responses likely have a very short time frame to eliminate

  9. Distinct Effector Memory CD4+ T Cell Signatures in Latent Mycobacterium tuberculosis Infection, BCG Vaccination and Clinically Resolved Tuberculosis

    PubMed Central

    Adekambi, Toidi; Ibegbu, Chris C.; Kalokhe, Ameeta S.; Yu, Tianwei; Ray, Susan M.; Rengarajan, Jyothi

    2012-01-01

    Two billion people worldwide are estimated to be latently infected with Mycobacterium tuberculosis (Mtb) and are at risk for developing active tuberculosis since Mtb can reactivate to cause TB disease in immune-compromised hosts. Individuals with latent Mtb infection (LTBI) and BCG-vaccinated individuals who are uninfected with Mtb, harbor antigen-specific memory CD4+ T cells. However, the differences between long-lived memory CD4+ T cells induced by latent Mtb infection (LTBI) versus BCG vaccination are unclear. In this study, we characterized the immune phenotype and functionality of antigen-specific memory CD4+ T cells in healthy BCG-vaccinated individuals who were either infected (LTBI) or uninfected (BCG) with Mtb. Individuals were classified into LTBI and BCG groups based on IFN-γ ELISPOT using cell wall antigens and ESAT-6/CFP-10 peptides. We show that LTBI individuals harbored high frequencies of late-stage differentiated (CD45RA−CD27−) antigen-specific effector memory CD4+ T cells that expressed PD-1. In contrast, BCG individuals had primarily early-stage (CD45RA−CD27+) cells with low PD-1 expression. CD27+ and CD27− as well as PD-1+ and PD-1− antigen-specific subsets were polyfunctional, suggesting that loss of CD27 expression and up-regulation of PD-1 did not compromise their capacity to produce IFN-γ, TNF-α and IL-2. PD-1 was preferentially expressed on CD27− antigen-specific CD4+ T cells, indicating that PD-1 is associated with the stage of differentiation. Using statistical models, we determined that CD27 and PD-1 predicted LTBI versus BCG status in healthy individuals and distinguished LTBI individuals from those who had clinically resolved Mtb infection after anti-tuberculosis treatment. This study shows that CD4+ memory responses induced by latent Mtb infection, BCG vaccination and clinically resolved Mtb infection are immunologically distinct. Our data suggest that differentiation into CD27−PD-1+ subsets in LTBI is driven by Mtb

  10. Intensification of Antiretroviral Therapy with a CCR5 Antagonist in Patients with Chronic HIV-1 Infection: Effect on T Cells Latently Infected

    PubMed Central

    Vallejo, Alejandro; Hernández-Novoa, Beatriz; Abad, María; Madrid, Nadia; Dahl, Viktor; Rubio, Rafael; Moreno, Ana M.; Dronda, Fernando; Casado, José Luis; Navas, Enrique; Pérez-Elías, María Jesús; Zamora, Javier; Palmer, Sarah; Muñoz, Eduardo; Muñoz-Fernández, María Ángeles; Moreno, Santiago

    2011-01-01

    Objective The primary objective was to assess the effect of MVC intensification on latently infected CD4+ T cells in chronically HIV-1-infected patients receiving antiretroviral therapy. Methods We performed an open-label pilot phase II clinical trial involving chronically HIV-1-infected patients receiving stable antiretroviral therapy whose regimen was intensified with 48 weeks of maraviroc therapy. We analyzed the latent reservoir, the residual viremia and episomal 2LTR DNA to examine the relationship between these measures and the HIV-1 latent reservoir, immune activation, lymphocyte subsets (including effector and central memory T cells), and markers associated with bacterial translocation. Results Overall a non significant reduction in the size of the latent reservoir was found (p = 0.068). A mean reduction of 1.82 IUPM was observed in 4 patients with detectable latent reservoir at baseline after 48 weeks of intensification. No effect on plasma residual viremia was observed. Unexpectedly, all the patients had detectable 2LTR DNA circles at week 24, while none of them showed those circles at the end of the study. No changes were detected in CD4+ or CD8+ counts, although a significant decrease was found in the proportion of HLA-DR+/CD38+ CD4+ and CD8+ T-cells. LPS and sCD14 levels increased. Conclusions Intensification with MVC was associated with a trend to a decrease in the size of the latent HIV-1 reservoir in memory T cells. No impact on residual viremia was detected. Additional studies with larger samples are needed to confirm the results. Trial Registration ClinicalTrials.gov NCT00795444 PMID:22174752

  11. HCMV protein LUNA is required for viral reactivation from latently infected primary CD14⁺ cells.

    PubMed

    Keyes, Lisa R; Hargett, Danna; Soland, Melisa; Bego, Mariana G; Rossetto, Cyprian C; Almeida-Porada, Graca; St Jeor, Stephen

    2012-01-01

    Human cytomegalovirus (HCMV) is a member of the Herpesviridae family that infects individuals throughout the world. Following an initial lytic stage, HCMV can persist in the individual for life in a non-active (or latent) form. During latency, the virus resides within cells of the myeloid lineage. The mechanisms controlling HCMV latency are not completely understood. A latency associated transcript, UL81-82ast, encoding the protein LUNA (Latency Unique Natural Antigen) was identified from latently infected donors in vivo. To address the role of the UL81-82ast protein product LUNA, in the context of the viral genome, we developed a recombinant HCMV bacterial artificial chromosome (BAC) that does not express LUNA. This construct, LUNA knockout FIX virus (FIX-ΔLUNA), was used to evaluate LUNA's role in HCMV latency. The FIX-ΔLUNA virus was able to lytically infect Human Fibroblast (HF) cells, showing that LUNA is not required to establish a lytic infection. Interestingly, we observed significantly higher viral copy numbers in HF cells infected with FIX-ΔLUNA when compared to FIX-WT virus. Furthermore, FIX-WT and FIX-ΔLUNA genomic DNA and transcription of UL81-82ast persisted over time in primary monocytes. In contrast, the levels of UL138 transcript expression in FIX-ΔLUNA infected HF and CD14⁺ cells was 100 and 1000 fold lower (respectively) when compared to the levels observed for FIX-WT infection. Moreover, FIX-ΔLUNA virus failed to reactivate from infected CD14⁺ cells following differentiation. This lack of viral reactivation was accompanied by a lack of lytic gene expression, increase in viral copy numbers, and lack of the production of infectious units following differentiation of the cells. Our study suggests that the LUNA protein is involved in regulating HCMV reactivation, and that in the absence of LUNA, HCMV may not be able to enter a proper latent state and therefore cannot be rescued from the established persistent infection in CD14⁺ cells.

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

    PubMed

    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.

  13. 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

  14. Latent herpes simplex virus-1 infection in SCID mice transferred with immune CD4+T cells: a new model for latency.

    PubMed

    Minagawa, H; Yanagi, Y

    2000-01-01

    In C.B-17 severe combined immunodeficiency (SCID) mice, corneal challenge with herpes simplex virus-1 (HSV-1) KOS strain usually leads to fatal encephalitis. With the transfer of T cells from immunized BALB/c mice, these SCID mice developed a latent HSV-1 infection. In order to determine the responsible T cell subset, fractionated immune T cells were transferred. Those SCID mice transferred with immune CD4+T cell-enriched fraction developed latent HSV-1 infection in their trigeminal ganglia. Their splenocytes had an increased percentage of CD4+T cells and showed a proliferative response against HSV-1. The transfer of CD8+T cells increased survival in the acute infection, but their engraftment seemed less needed for latency than that of CD4+T cells. Mice that received immune serum survived without developing latent HSV-1 infection. Some latently infected SCID mice had anti-HSV antibodies while others did not, indicating that the engraftment of antibody-producing B cells was not required for latency. Thus, immune CD4+T cells were important for the survival of SCID mice with latent HSV-1 infection. This animal model should be useful for investigation of latency/reactivation of HSV-1.

  15. 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.

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

    DOE PAGES

    Ke, Ruian; Lewin, Sharon R.; Elliott, Julian H.; ...

    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

  17. 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.

  18. Evidence that herpes simplex virus DNA derived from quiescently infected cells in vitro, and latently infected cells in vivo, is physically damaged

    PubMed Central

    Millhouse, Scott; Su, Ying-Hsiu; Zhang, Xianchao; Wang, Xiaohe; Song, Benjamin P.; Zhu, Li; Oppenheim, Emily; Fraser, Nigel W.; Block, Timothy M.

    2010-01-01

    Using PCR and alkaline gel electrophoresis, we show that, compared with DNA derived from virions used to establish infection, herpes simplex virus DNA derived from quiescently infected rat pheochromocytoma (PC12) cells in culture accumulates alkaline-labile lesions. That is, compared with equivalent amounts of virion DNA, viral DNA from nerve growth factor-differentiated long-term infected cells in culture is consistently 3 to 10 times more refractory to amplification by PCR. Despite using equal mole amounts of DNA isolated from quiescently infected cells (determined by quantitative Southern blots), DNA from quiescently infected cells could not be detected by PCR under conditions in which the virion-derived DNA was easily detected. Refractoriness to PCR was confirmed by analysis with a ligation-mediated PCR technique. The refractoriness was not the result of genomic circularization. The refractoriness was, however, related to the time that the quiescently infected cells had been maintained in culture. The refractoriness to PCR was taken as an indication that the viral DNA was damaged. This hypothesis was confirmed by showing that viral DNA from quiescently infected PC12 cells accumulated alkaline-labile DNA lesions, as determined by alkaline gel electrophoresis. The phenomenon was not limited to tissue culture, because viral DNA derived from the ganglia of latently infected mice is also 3 to 10 times more refractory to amplification than are equivalent amounts of virion-derived genomes. Taken together, these results represent the first evidence that herpes simplex virus DNA is physically damaged as a function of long-term infection. Implications for viral reactivation and pathogenesis are discussed. PMID:20874012

  19. 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

  20. CD8+ T Cells Play a Bystander Role in Mice Latently Infected with Herpes Simplex Virus 1

    PubMed Central

    Mott, Kevin R.; Gate, David; Matundan, Harry H.; Ghiasi, Yasamin N.; Town, Terrence

    2016-01-01

    ABSTRACT Based on an explant reactivation model, it has been proposed that CD8+ T cells maintain latency in trigeminal ganglia (TG) of mice latently infected with herpes simplex virus 1 (HSV-1) [T. Liu, K. M. Khanna, X. Chen, D. J. Fink, and R. L. Hendricks, J Exp Med 191:1459–1466, 2000, doi:10.1084/jem.191.9.1459; K. M. Khanna, R. H. Bonneau, P. R. Kinchington, and R. L. Hendricks, Immunity 18:593-603, 2003, doi:10.1016/S1074-7613(03)00112-2]. In those studies, BALB/c mice were ocularly infected with an avirulent HSV-1 strain (RE) after corneal scarification. However, in our studies, we typically infect mice with a virulent HSV-1 strain (McKrae) that does not require corneal scarification. Using a combination of knockout mice, adoptive transfers, and depletion studies, we recently found that CD8α+ dendritic cells (DCs) contribute to HSV-1 latency and reactivation in TG of ocularly infected mice (K. R. Mott, S. J. Allen, M. Zandian, B. Konda, B. G. Sharifi, C. Jones, S. L. Wechsler, T. Town, and H. Ghiasi, PLoS One 9:e93444, 2014, doi:10.1371/journal.pone.0093444). This suggested that CD8+ T cells might not be the major regulators of HSV-1 latency in the mouse TG. To investigate this iconoclastic possibility, we used a blocking CD8 antibody and CD8+ T cells in reactivated TG explants from mice latently infected with (i) the avirulent HSV-1 strain RE following corneal scarification or (ii) the virulent HSV-1 strain McKrae without corneal scarification. Independently of the strain or approach, our results show that CD8α+ DCs, not CD8+ T cells, drive latency and reactivation. In addition, adoptive transfer of CD8+ T cells from wild-type (wt) mice to CD8α−/− mice did not restore latency to the level for wt mice or wt virus. In the presence of latency-associated transcript (LAT(+); wt virus), CD8+ T cells seem to play a bystander role in the TG. These bystander T cells highly express PD-1, most likely due to the presence of CD8α+ DCs. Collectively, these

  1. CD8+ T Cells Play a Bystander Role in Mice Latently Infected with Herpes Simplex Virus 1.

    PubMed

    Mott, Kevin R; Gate, David; Matundan, Harry H; Ghiasi, Yasamin N; Town, Terrence; Ghiasi, Homayon

    2016-05-15

    Based on an explant reactivation model, it has been proposed that CD8(+) T cells maintain latency in trigeminal ganglia (TG) of mice latently infected with herpes simplex virus 1 (HSV-1) [T. Liu, K. M. Khanna, X. Chen, D. J. Fink, and R. L. Hendricks, J Exp Med 191:1459-1466, 2000, doi:10.1084/jem.191.9.1459; K. M. Khanna, R. H. Bonneau, P. R. Kinchington, and R. L. Hendricks, Immunity 18:593-603, 2003, doi:10.1016/S1074-7613(03)00112-2]. In those studies, BALB/c mice were ocularly infected with an avirulent HSV-1 strain (RE) after corneal scarification. However, in our studies, we typically infect mice with a virulent HSV-1 strain (McKrae) that does not require corneal scarification. Using a combination of knockout mice, adoptive transfers, and depletion studies, we recently found that CD8α(+) dendritic cells (DCs) contribute to HSV-1 latency and reactivation in TG of ocularly infected mice (K. R. Mott, S. J. Allen, M. Zandian, B. Konda, B. G. Sharifi, C. Jones, S. L. Wechsler, T. Town, and H. Ghiasi, PLoS One 9:e93444, 2014, doi:10.1371/journal.pone.0093444). This suggested that CD8(+) T cells might not be the major regulators of HSV-1 latency in the mouse TG. To investigate this iconoclastic possibility, we used a blocking CD8 antibody and CD8(+) T cells in reactivated TG explants from mice latently infected with (i) the avirulent HSV-1 strain RE following corneal scarification or (ii) the virulent HSV-1 strain McKrae without corneal scarification. Independently of the strain or approach, our results show that CD8α(+) DCs, not CD8(+) T cells, drive latency and reactivation. In addition, adoptive transfer of CD8(+) T cells from wild-type (wt) mice to CD8α(-/-) mice did not restore latency to the level for wt mice or wt virus. In the presence of latency-associated transcript (LAT((+)); wt virus), CD8(+) T cells seem to play a bystander role in the TG. These bystander T cells highly express PD-1, most likely due to the presence of CD8α(+) DCs. Collectively

  2. Treatment of Latent Tuberculosis Infection.

    PubMed

    Haley, Connie A

    2017-04-01

    There are approximately 56 million people who harbor Mycobacterium tuberculosis that may progress to active tuberculosis (TB) at some point in their lives. Modeling studies suggest that if only 8% of these individuals with latent TB infection (LTBI) were treated annually, overall global incidence would be 14-fold lower by 2050 compared to incidence in 2013, even in the absence of additional TB control measures. This highlights the importance of identifying and treating latently infected individuals, and that this intervention must be scaled up to achieve the goals of the Global End TB Strategy. The efficacy of LTBI treatment is well established, and the most commonly used regimen is 9 months of daily self-administered isoniazid. However, its use has been hindered by limited provider awareness of the benefits, concern about potential side effects such as hepatotoxicity, and low rates of treatment completion. There is increasing evidence that shorter rifamycin-based regimens are as effective, better tolerated, and more likely to be completed compared to isoniazid. Such regimens include four months of daily self-administered rifampin monotherapy, three months of once weekly directly observed isoniazid-rifapentine, and three months of daily self-administered isoniazid-rifampin. The success of LTBI treatment to prevent additional TB disease relies upon choosing an appropriate regimen individualized to the patient, monitoring for potential adverse clinical events, and utilizing strategies to promote adherence. Safer, more cost-effective, and more easily completed regimens are needed and should be combined with interventions to better identify, engage, and retain high-risk individuals across the cascade from diagnosis through treatment completion of LTBI.

  3. In vivo analysis of the effect of panobinostat on cell-associated HIV RNA and DNA levels and latent HIV infection.

    PubMed

    Tsai, Perry; Wu, Guoxin; Baker, Caroline E; Thayer, William O; Spagnuolo, Rae Ann; Sanchez, Rosa; Barrett, Stephanie; Howell, Bonnie; Margolis, David; Hazuda, Daria J; Archin, Nancie M; Garcia, J Victor

    2016-05-21

    The latent reservoir in resting CD4(+) T cells presents a major barrier to HIV cure. Latency-reversing agents are therefore being developed with the ultimate goal of disrupting the latent state, resulting in induction of HIV expression and clearance of infected cells. Histone deacetylase inhibitors (HDACi) have received a significant amount of attention for their potential as latency-reversing agents. Here, we have investigated the in vitro and systemic in vivo effect of panobinostat, a clinically relevant HDACi, on HIV latency. We showed that panobinostat induces histone acetylation in human PBMCs. Further, we showed that panobinostat induced HIV RNA expression and allowed the outgrowth of replication-competent virus ex vivo from resting CD4(+) T cells of HIV-infected patients on suppressive antiretroviral therapy (ART). Next, we demonstrated that panobinostat induced systemic histone acetylation in vivo in the tissues of BLT humanized mice. Finally, in HIV-infected, ART-suppressed BLT mice, we evaluated the effect of panobinostat on systemic cell-associated HIV RNA and DNA levels and the total frequency of latently infected resting CD4(+) T cells. Our data indicate that panobinostat treatment resulted in systemic increases in cellular levels of histone acetylation, a key biomarker for in vivo activity. However, panobinostat did not affect the levels of cell-associated HIV RNA, HIV DNA, or latently infected resting CD4(+) T cells. We have demonstrated robust levels of systemic histone acetylation after panobinostat treatment of BLT humanized mice; and we did not observe a detectable change in the levels of cell-associated HIV RNA, HIV DNA, or latently infected resting CD4(+) T cells in HIV-infected, ART-suppressed BLT mice. These results are consistent with the modest effects noted in vitro and suggest that combination therapies may be necessary to reverse latency and enable clearance. Animal models will contribute to the progress towards an HIV cure.

  4. Functional profile of CD4+ and CD8+ T cells in latently infected individuals and patients with active TB.

    PubMed

    Marín, Nancy D; París, Sara C; Rojas, Mauricio; García, Luis F

    2013-03-01

    Tuberculosis (TB) is one of the most important infectious diseases around the world. Several studies have focused on the identification of correlates of protection against TB. Most of them have concentrated on the study of IFN-γ due to its robust association with protection against TB. However, given the complexity of the immune response elicited after Mtb infection, other cytokines should also be considered. In the present study, we evaluated Th1 and Th17 responses and their association with the protection or development of active disease. Therefore, non infected individuals (nonTBi), latently infected individuals (LTBi) and patients with active TB (ATB) were studied. The evaluation of the number of cytokine producing cells by ELISPOT showed a higher number of IFN-γ-producing cells in ATB patients, but no differences were found regarding the number of IL-17 producing cells among studied groups. The evaluation of IFN-γ, IL-2, TNF-α and IL-17 producing CD4+ and CD8+ T cells at 1 day and 6 days of stimulation with mycobacterial antigens suggests the presence of functional signatures associated with latency or active TB. The results presented herein suggest the possible use of the evaluation of Th1-type cytokines, such as IFN-γ and/or TNF-α, as a correlate of protection against TB; however, these results need to be validated for other groups.

  5. Telomere length dynamics in human memory T cells specific for viruses causing acute or latent infections

    PubMed Central

    2013-01-01

    Background Declining telomere length (TL) is associated with T cell senescence. While TL in naïve and memory T cells declines with increasing age, there is limited data on TL dynamics in virus-specific memory CD4+ T cells in healthy adults. We combined BrdU-labeling of virus-stimulated T cells followed with flow cytometry-fluorescent in situ hybridization for TL determination. We analyzed TL in T cells specific for several virus infections: non-recurring acute (vaccinia virus, VACV), recurring-acute (influenza A virus, IAV), and reactivating viruses (varicella-zoster virus, VZV, and cytomegalovirus, CMV) in 10 healthy subjects. Additionally, five subjects provided multiple blood samples separated by up to 10 years. Results VACV- and CMV-specific T cells had longer average TL than IAV-specific CD4+ T cells. Although most virus-specific cells were CD45RA-, we observed a minor population of BrdU+ CD45RA+ T cells characterized by long telomeres. Longitudinal analysis demonstrated a slow decline in average TL in virus-specific T cells. However, in one subject, VZV reactivation led to an increase in average TL in VZV-specific memory T cells, suggesting a conversion of longer TL cells from the naïve T cell repertoire. Conclusions TLs in memory CD4+ T cells in otherwise healthy adults are heterogeneous and follow distinct virus-specific kinetics. These findings suggests that the distribution of TL and the creation and maintenance of long TL memory T cells could be important for the persistence of long-lived T cell memory. PMID:23971624

  6. Identifcation of differentially expressed long non-coding RNAs in CD4+ T cells response to latent tuberculosis infection.

    PubMed

    Yi, Zhengjun; Li, Jianhua; Gao, Kunshan; Fu, Yurong

    2014-12-01

    To identify differentially expressed long non-coding RNAs (lncRNAs) in CD4(+) T cells triggered upon latent tuberculosis (TB) infection. Expression profiles of lncRNAs and mRNAs in CD4(+) T cells from individuals with latent TB infection (LTBI), active TB and healthy controls were analyzed by microarray assay and four lncRNAs were selected for validation using real time-quantitative polymerase chain reaction (RT-qPCR). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway based approaches were used to investigate biological functions and signaling pathways affected by the differentially expressed mRNAs. LncRNAs and mRNAs in CD4(+) T cells were involved in LTBI and active TB disease. Compared with healthy controls, 449 lncRNAs and 461 mRNAs were deregulated in LTBI group, 1,113 lncRNAs and 1,490 mRNAs were deregulated in active TB group, as well as 163 lncRNAs and 187 mRNAs were differentially expressed in both LTBI and active TB group. It was worth noting that 41 lncRNAs and 60 mRNAs were deregulated between three groups. Most deregulated lncRNAs were from intergenic regions (∼ 50%), natural antisense to protein-coding loci (∼ 20%), or intronic antisense to protein-coding loci (∼ 10%). Significantly enriched signaling pathways based on deregulated mRNAs were mainly involved in mitogen-activated protein kinase (MAPK) signaling pathway, cytokine-cytokine receptor interaction, Toll-like receptor signaling pathway, etc. The study was the first report of differentially expressed lncRNAs in CD4(+) T cells response to TB infection and indicated that some lncRNAs may be involved in regulating host immune response to TB infection. Future studies are needed to further elucidate potential roles of these deregulated lncRNAs in LTBI and its reactivation. Copyright © 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  7. Susceptibility to CD8 T-cell-mediated killing influences the reservoir of latently HIV-1-infected CD4 T cells.

    PubMed

    Buzon, Maria J; Yang, Yue; Ouyang, Zhengyu; Sun, Hong; Seiss, Katherine; Rogich, Jerome; Le Gall, Sylvie; Pereyra, Florencia; Rosenberg, Eric S; Yu, Xu G; Lichterfeld, Mathias

    2014-01-01

    HIV-1 establishes a lifelong infection in the human body, but host factors that influence viral persistence remain poorly understood. Cell-intrinsic characteristics of CD4 T cells, the main target cells for HIV-1, may affect the composition of the latent viral reservoir by altering the susceptibility to CD8 T-cell-mediated killing. We observed that susceptibilities of CD4 T cells to CD8 T-cell-mediated killing, as determined in direct ex vivo assays, were significantly higher in persons with natural control of HIV-1 (elite controllers) than in individuals effectively treated with antiretroviral therapy. These differences were most pronounced in naive and in terminally differentiated CD4 T cells and corresponded to a reduced viral reservoir size in elite controllers. Interestingly, the highest susceptibility to CD8 T-cell-mediated killing and lowest reservoirs of cell-associated HIV-1 DNA was consistently observed in elite controllers expressing the protective HLA class I allele B57. These data suggest that the functional responsiveness of host CD4 T cells to cytotoxic effects of HIV-1-specific CD8 T cells can contribute to shaping the structure and composition of the latently infected CD4 T-cell pool.

  8. Epstein-Barr virus latently infected cells are selectively deleted in simulated-microgravity cultures.

    PubMed

    Long, J P; Hughes, J H

    2001-04-01

    Rotating-wall vessels (RWVs) allow for the cultivation of cells in simulated microgravity. Previously, we showed that the cultivation of lymphoblastoid cells in simulated microgravity results in the suppression of Epstein-Barr virus (EBV) reactivation. To determine if the suppression generated by simulated microgravity could be reversed by changing to static culture conditions, cells were cultured in an RRWV for 5 d, and then switched to static conditions. Following the switch to static conditions, viral reactivation remained suppressed (significantly lower) relative to static control cultures over a 4-d period. Additionally, experiments were conducted to determine if chemical treatment could induce viral reactivation in cells from simulated-microgravity cultures. Cells were cultured in static flask cultures and in simulated microgravity in RWVs for 4-7 d. The cells were then transferred to 50-cm3 tubes, and treated with 3 mM n-butyrate for 48 h, or 18 ng/ml of phorbol ester, viz., 12-0-tetradecanoylphorbol-13 acetate (TPA) for either 2 or 48 h, under static conditions. Although EBV was inducible, the cells from simulated-microgravity cultures treated with n-butyrate displayed significantly lower levels of viral-antigen expression compared with the treated cells from static cultures. Also, incubation with TPA for 2-3 h, but not for 48 h, reactivated EBV in cells from RWV cultures. In contrast, EBV was inducible in cells from static cultures treated for either 2-3 or 48 h with TPA. TPA reactivation of EBV following a 2-3-h period of treatment indicates that the protein kinase C signal-transduction pathway is not impaired in lymphoblastoid cells cultured in simulated microgravity. However, the exposure of B-lymphoblastoid cells from simulated-microgravity cultures to TPA for more than 3-4 h triggered a lytic event (apoptosis or necrosis), which prevented replication of the virus. Thus, EBV-infected cells in simulated microgravity were negatively selected in the

  9. 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

  10. Attenuated Listeria monocytogenes Vectors Overcome Suppressive Plasma Factors During HIV Infection to Stimulate Myeloid Dendritic Cells to Promote Adaptive Immunity and Reactivation of Latent Virus

    PubMed Central

    Miller, Elizabeth A.; Spadaccia, Meredith R.; Norton, Thomas; Demmler, Morgan; Gopal, Ramya; O'Brien, Meagan; Landau, Nathaniel; Dubensky, Thomas W.; Lauer, Peter; Brockstedt, Dirk G.

    2015-01-01

    Abstract HIV-1 infection is characterized by myeloid dendritic cell (DC) dysfunction, which blunts the responsiveness to vaccine adjuvants. We previously showed that nonviral factors in HIV-seropositive plasma are partially responsible for mediating this immune suppression. In this study we investigated recombinant Listeria monocytogenes (Lm) vectors, which naturally infect and potently activate DCs from seronegative donors, as a means to overcome DC dysfunction associated with HIV infection. Monocyte-derived DCs were cocultured with plasma from HIV-infected donors (HIV-moDCs) to induce a dysregulated state and infected with an attenuated, nonreplicative vaccine strain of Lm expressing full length clade B consensus gag (KBMA Lm-gag). Lm infection stimulated cytokine secretion [interleukin (IL)-12p70, tumor necrosis factor (TNF)-α, and IL-6] and Th-1 skewing of allogeneic naive CD4 T cells by HIV-moDCs, in contrast to the suppressive effects observed by HIV plasma on moDCs on toll-like receptor ligand stimulation. Upon coculture of “killed” but metabolically active (KBMA) Lm-gag-infected moDCs from HIV-infected donors with autologous cells, expansion of polyfunctional, gag-specific CD8+ T cells was observed. Reactivation of latent proviruses by moDCs following Lm infection was also observed in models of HIV latency in a TNF-α-dependent manner. These findings reveal the unique ability of Lm vectors to contend with dysregulation of HIV-moDCs, while simultaneously possessing the capacity to activate latent virus. Concurrent stimulation of innate and adaptive immunity and disruption of latency may be an approach to reduce the pool of latently infected cells during HIV infection. Further study of Lm vectors as part of therapeutic vaccination and eradication strategies may advance this evolving field. PMID:25376024

  11. The integrase cofactor LEDGF/p75 associates with Iws1 and Spt6 for postintegration silencing of HIV-1 gene expression in latently infected cells.

    PubMed

    Gérard, Annabelle; Ségéral, Emmanuel; Naughtin, Monica; Abdouni, Ahmed; Charmeteau, Bénédicte; Cheynier, Rémi; Rain, Jean-Christophe; Emiliani, Stéphane

    2015-01-14

    The persistence of a latent reservoir containing transcriptionally silent, but replication-competent, integrated provirus is a serious challenge to HIV eradication. HIV integration is under the control of LEDGF/p75, the cellular cofactor of viral integrase. Investigating possible postintegration roles for LEDGF/p75, we find that LEDGF/p75 represses HIV expression in latently infected cells. LEDGF/p75 associated with two proteins involved in the control of gene expression and chromatin structure, Spt6 and Iws1, to form a stable complex. Iws1 plays a role in the establishment of latent infection, whereas Spt6 functions to recruit Iws1 and LEDGF/p75 to the silenced provirus and maintains histone occupancy at the HIV promoter. In latently infected cells, depletion of the complex results in reactivation of HIV expression Altogether, our results indicate that a complex containing LEDGF/p75, Iws1, and Spt6 participates in regulating postintegration steps of HIV latency. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Transactivation activity of Meq, a Marek's disease herpesvirus bZIP protein persistently expressed in latently infected transformed T cells.

    PubMed Central

    Qian, Z; Brunovskis, P; Rauscher, F; Lee, L; Kung, H J

    1995-01-01

    Marek's disease virus (MDV) is an avian herpesvirus that induces a variety of diseases, including T-cell lymphomas, in chickens. In latently infected, transformed lymphoid cells, very few viral transcripts or proteins are detected. We previously described a gene, meq (MDV EcoQ), which is persistently expressed in MDV-transformed tumor samples and cell lines. meq codes for a 339-amino-acid protein with a basic-leucine zipper domain near its N terminus and a proline-rich domain near its C terminus. The basic-leucine zipper domain shows homology with Jun/Fos family proteins, whereas the proline-rich domain resembles that of the WT-1 tumor suppressor protein. These structural features raise the possibility that Meq functions as a transcription factor in regulating viral latency or oncogenesis. In this report, we show that the proline-rich domain is a potent transcription activator when fused to the yeast (Saccharomyces cerevisiae) Gal4(1-147) DNA-binding domain. The transactivation activity maps to the C-terminal 130 amino acids, with the last 33 amino acids essential. In the absence of these 33 amino acids, a two-and-one-half proline-rich repeat structure was found to exhibit repression activity. We further show that Meq is able to dimerize not only with itself but also with c-Jun. Meq/c-Jun heterodimers bind to an AP1-like sequence in the meq promoter region with an affinity much greater than that of Meq/Meq or c-Jun/c-Jun homodimers. Cotransfection chloramphenicol acetyltransferase assays suggest that the Meq/c-Jun heterodimers can up-regulate Meq expression in both chicken embryo fibroblasts and F9 cells. Our data provide the first biochemical evidence that Meq is a transcriptional factor and identify c-Jun as one of Meq's interacting partners. PMID:7769661

  13. γδ T-cell function is inhibited in end-stage renal disease and impacted by latent tuberculosis infection.

    PubMed

    Juno, Jennifer A; Waruk, Jillian L M; Harris, Angela; Mesa, Christine; Lopez, Carmen; Bueti, Joe; Ball, T Blake; Kiazyk, Sandra A

    2017-10-01

    Patients with end-stage renal disease (ESRD) are at elevated risk of acquiring infectious diseases, including tuberculosis (TB). Inflammation and uremia negatively impact immune function in this population, but specific pathways involved in TB immunity have not been identified. Although γδ T cells are known to contribute to protection from TB, their phenotype and function in patients with ESRD is relatively unknown. To determine this we recruited 20 patients with and 20 without ESRD (controls), with or without latent TB infection to assess γδ T cell frequency, surface phenotype, and cytokine production by flow cytometry in response to stimulation. γδ T cells derived from patients with ESRD exhibited significantly lower expression of CCR5, CXCR3, and CD26 compared to controls. Furthermore, patients with ESRD, particularly the group with latent TB infection, exhibited poor IFNγ, TNFα, and GMCSF responses to stimulation with either phosphoantigen HMB-PP, IL-12/IL-18, E. coli, or phorbol myristate acetate and ionomycin. Similar dysfunctional responses were observed in patients with active TB. Surprisingly, neither the γδ phenotype nor its function was associated with plasma markers of inflammation or microbial translocation. Thus, there is significant perturbation of the γδ T-cell population in patients with ESRD, particularly in those with latent TB infection. Copyright © 2017 International Society of Nephrology. All rights reserved.

  14. 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.

  15. The Role of LAT in Increased CD8+ T Cell Exhaustion in Trigeminal Ganglia of Mice Latently Infected with Herpes Simplex Virus 1▿

    PubMed Central

    Allen, Sariah J.; Hamrah, Pedram; Gate, David; Mott, Kevin R.; Mantopoulos, Dimosthenis; Zheng, Lixin; Town, Terrence; Jones, Clinton; von Andrian, Ulrich H.; Freeman, Gordon J.; Sharpe, Arlene H.; BenMohamed, Lbachir; Ahmed, Rafi; Wechsler, Steven L.; Ghiasi, Homayon

    2011-01-01

    Herpes simplex virus (HSV) infection is a classic example of latent viral infection in humans and experimental animal models. The HSV-1 latency-associated transcript (LAT) plays a major role in the HSV-1 latency reactivation cycle and thus in recurrent disease. Whether the presence of LAT leads to generation of dysfunctional T cell responses in the trigeminal ganglia (TG) of latently infected mice is not known. To address this issue, we used LAT-positive [LAT(+)] and LAT-deficient [LAT(−)] viruses to evaluate the effect of LAT on CD8 T cell exhaustion in TG of latently infected mice. The amount of latency as determined by quantitative reverse transcription-PCR (qRT-PCR) of viral DNA in total TG extracts was 3-fold higher with LAT(+) than with LAT(−) virus. LAT expression and increased latency correlated with increased mRNA levels of CD8, PD-1, and Tim-3. PD-1 is both a marker for exhaustion and a primary factor leading to exhaustion, and Tim-3 can also contribute to exhaustion. These results suggested that LAT(+) TG contain both more CD8+ T cells and more CD8+ T cells expressing the exhaustion markers PD-1 and Tim-3. This was confirmed by flow cytometry analyses of expression of CD3/CD8/PD-1/Tim-3, HSV-1, CD8+ T cell pentamer (specific for a peptide derived from residues 498 to 505 of glycoprotein B [gB498–505]), interleukin-2 (IL-2), and tumor necrosis factor alpha (TNF-α). The functional significance of PD-1 and its ligands in HSV-1 latency was demonstrated by the significantly reduced amount of HSV-1 latency in PD-1- and PD-L1-deficient mice. Together, these results may suggest that both PD-1 and Tim-3 are mediators of CD8+ T cell exhaustion and latency in HSV-1 infection. PMID:21307196

  16. The role of LAT in increased CD8+ T cell exhaustion in trigeminal ganglia of mice latently infected with herpes simplex virus 1.

    PubMed

    Allen, Sariah J; Hamrah, Pedram; Gate, David; Mott, Kevin R; Mantopoulos, Dimosthenis; Zheng, Lixin; Town, Terrence; Jones, Clinton; von Andrian, Ulrich H; Freeman, Gordon J; Sharpe, Arlene H; BenMohamed, Lbachir; Ahmed, Rafi; Wechsler, Steven L; Ghiasi, Homayon

    2011-05-01

    Herpes simplex virus (HSV) infection is a classic example of latent viral infection in humans and experimental animal models. The HSV-1 latency-associated transcript (LAT) plays a major role in the HSV-1 latency reactivation cycle and thus in recurrent disease. Whether the presence of LAT leads to generation of dysfunctional T cell responses in the trigeminal ganglia (TG) of latently infected mice is not known. To address this issue, we used LAT-positive [LAT(+)] and LAT-deficient [LAT(-)] viruses to evaluate the effect of LAT on CD8 T cell exhaustion in TG of latently infected mice. The amount of latency as determined by quantitative reverse transcription-PCR (qRT-PCR) of viral DNA in total TG extracts was 3-fold higher with LAT(+) than with LAT(-) virus. LAT expression and increased latency correlated with increased mRNA levels of CD8, PD-1, and Tim-3. PD-1 is both a marker for exhaustion and a primary factor leading to exhaustion, and Tim-3 can also contribute to exhaustion. These results suggested that LAT(+) TG contain both more CD8(+) T cells and more CD8(+) T cells expressing the exhaustion markers PD-1 and Tim-3. This was confirmed by flow cytometry analyses of expression of CD3/CD8/PD-1/Tim-3, HSV-1, CD8(+) T cell pentamer (specific for a peptide derived from residues 498 to 505 of glycoprotein B [gB(498-505)]), interleukin-2 (IL-2), and tumor necrosis factor alpha (TNF-α). The functional significance of PD-1 and its ligands in HSV-1 latency was demonstrated by the significantly reduced amount of HSV-1 latency in PD-1- and PD-L1-deficient mice. Together, these results may suggest that both PD-1 and Tim-3 are mediators of CD8(+) T cell exhaustion and latency in HSV-1 infection.

  17. Ets-1 Is Required for the Activation of VEGFR3 during Latent Kaposi's Sarcoma-Associated Herpesvirus Infection of Endothelial Cells

    PubMed Central

    Gutierrez, Kimberley D.; Morris, Valerie A.; Wu, David; Barcy, Serge

    2013-01-01

    Kaposi's sarcoma-associated herpesvirus (KSHV), the etiologic agent of Kaposi's sarcoma (KS), is present in the predominant tumor cells of KS, the spindle cells. Spindle cells express markers of lymphatic endothelium and, interestingly, KSHV infection of blood endothelial cells reprograms them to a lymphatic endothelial cell phenotype. KSHV-induced reprogramming requires the activation of STAT3 and phosphatidylinositol 3 (PI3)/AKT through the activation of cellular receptor gp130. Importantly, KSHV-induced reprogramming is specific to endothelial cells, indicating that there are additional host genes that are differentially regulated during KSHV infection of endothelial cells that contribute to lymphatic reprogramming. We found that the transcription factor Ets-1 is highly expressed in KS spindle cells and is upregulated during KSHV infection of endothelial cells in culture. The KSHV latent vFLIP gene is sufficient to induce Ets-1 expression in an NF-κB-dependent fashion. Ets-1 is required for KSHV-induced expression of VEGFR3, a lymphatic endothelial-cell-specific receptor important for lymphangiogenesis, and Ets-1 activates the promoter of VEGFR3. Ets-1 knockdown does not alter the expression of another lymphatic-specific gene, the podoplanin gene, but does inhibit the expression of VEGFR3 in uninfected lymphatic endothelium, indicating that Ets-1 is a novel cellular regulator of VEGFR3 expression. Knockdown of Ets-1 affects the ability of KSHV-infected cells to display angiogenic phenotypes, indicating that Ets-1 plays a role in KSHV activation of endothelial cells during latent KSHV infection. Thus, Ets-1 is a novel regulator of VEGFR3 and is involved in the induction of angiogenic phenotypes by KSHV. PMID:23552426

  18. Ets-1 is required for the activation of VEGFR3 during latent Kaposi's sarcoma-associated herpesvirus infection of endothelial cells.

    PubMed

    Gutierrez, Kimberley D; Morris, Valerie A; Wu, David; Barcy, Serge; Lagunoff, Michael

    2013-06-01

    Kaposi's sarcoma-associated herpesvirus (KSHV), the etiologic agent of Kaposi's sarcoma (KS), is present in the predominant tumor cells of KS, the spindle cells. Spindle cells express markers of lymphatic endothelium and, interestingly, KSHV infection of blood endothelial cells reprograms them to a lymphatic endothelial cell phenotype. KSHV-induced reprogramming requires the activation of STAT3 and phosphatidylinositol 3 (PI3)/AKT through the activation of cellular receptor gp130. Importantly, KSHV-induced reprogramming is specific to endothelial cells, indicating that there are additional host genes that are differentially regulated during KSHV infection of endothelial cells that contribute to lymphatic reprogramming. We found that the transcription factor Ets-1 is highly expressed in KS spindle cells and is upregulated during KSHV infection of endothelial cells in culture. The KSHV latent vFLIP gene is sufficient to induce Ets-1 expression in an NF-κB-dependent fashion. Ets-1 is required for KSHV-induced expression of VEGFR3, a lymphatic endothelial-cell-specific receptor important for lymphangiogenesis, and Ets-1 activates the promoter of VEGFR3. Ets-1 knockdown does not alter the expression of another lymphatic-specific gene, the podoplanin gene, but does inhibit the expression of VEGFR3 in uninfected lymphatic endothelium, indicating that Ets-1 is a novel cellular regulator of VEGFR3 expression. Knockdown of Ets-1 affects the ability of KSHV-infected cells to display angiogenic phenotypes, indicating that Ets-1 plays a role in KSHV activation of endothelial cells during latent KSHV infection. Thus, Ets-1 is a novel regulator of VEGFR3 and is involved in the induction of angiogenic phenotypes by KSHV.

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

    PubMed

    Poole, Emma; Lau, Jonathan C H; Sinclair, John

    2015-08-01

    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.

  20. Enhancing Virion Tethering by BST2 Sensitizes Productively and Latently HIV-infected T cells to ADCC Mediated by Broadly Neutralizing Antibodies

    PubMed Central

    Pham, Tram N. Q.; Lukhele, Sabelo; Dallaire, Frédéric; Perron, Gabrielle; Cohen, Éric A.

    2016-01-01

    Binding of anti-HIV antibodies (Abs) to envelope (Env) glycoproteins on infected cells can mark them for elimination via antibody-dependent cell-mediated cytotoxicity (ADCC). BST2, a type I interferon (IFN)-stimulated restriction factor that anchors nascent Env-containing virions at the surface of infected cells has been shown to enhance ADCC functions. In a comprehensive analysis of ADCC potency by neutralizing anti-HIV Abs (NAbs), we show in this study that NAbs are capable of mediating ADCC against HIV-infected T cells with 3BNC117, PGT126 and PG9 being most efficient. We demonstrate that HIV-induced BST2 antagonism effectively attenuates Ab binding and ADCC responses mediated by all classes of NAbs that were tested. Interestingly, IFNα treatment can reverse this effect in a BST2-dependent manner. Importantly, while reactivated latent T cell lines display some susceptibility to ADCC mediated by broadly NAbs, inactivating BST2 viral countermeasures and/or exogenous IFNα augment their elimination. Overall, our findings support the notion that NAbs can induce ADCC. They highlight that while BST2 antagonism by HIV promotes ADCC evasion, strategies aimed at restoring BST2 restriction could improve anti-HIV responses and potentially provide a means to eliminate reactivated cells in latent reservoirs. PMID:27853288

  1. 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

  2. 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.

  3. Lytic gene expression is frequent in HSV-1 latent infection and correlates with the engagement of a cell-intrinsic transcriptional response.

    PubMed

    Ma, Joel Z; Russell, Tiffany A; Spelman, Tim; Carbone, Francis R; Tscharke, David C

    2014-07-01

    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.

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

    PubMed

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

    2015-07-01

    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 multiparametric 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.

  5. Immune parameters differentiating active from latent tuberculosis infection in humans.

    PubMed

    Lee, Ji Yeon; Jung, Young Won; Jeong, Ina; Joh, Joon-Sung; Sim, Soo Yeon; Choi, Boram; Jee, Hyeon-Gun; Lim, Dong-Gyun

    2015-12-01

    Tuberculosis remains a highly prevalent infectious disease worldwide. Identification of the immune parameters that differentiate active disease from latent infection will facilitate the development of efficient control measures as well as new diagnostic modalities for tuberculosis. Here, we investigated the cytokine production profiles of monocytes and CD4(+) T lymphocytes upon encountering mycobacterial antigens. In addition, cytokines and lipid mediators with immune-modulating activities were examined in plasma samples ex vivo. Comparison of these parameters in active tuberculosis patients and healthy subjects with latent infection revealed that, active tuberculosis was associated with diminished Th1-type cytokine secretion from CD4(+) T cells and less augmented inflammatory cytokine secretion from monocytes induced by IFN-γ than that in latent tuberculosis infection. In addition, a higher plasma concentration of lipoxin A4 and lower ratio of prostaglandin E2 to lipoxin A4 were observed in active cases than in latent infections. These findings have implications for preparing new therapeutic strategies and for differential diagnosis of the two types of tuberculosis infection.

  6. 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

  7. 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

  8. 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

  9. Immunological and pharmacological strategies to reactivate HIV-1 from latently infected cells: a possibility for HIV-1 paediatric patients?

    PubMed

    Martínez-Bonet, M; Clemente, M I; Serramía, M J; Moreno, S; Muñoz, E; Muñoz-Fernández, M A

    2015-07-01

    The limitations to establishing a viral reservoir facilitated by early cART in children could play a critical role in achieving natural control of viral replication upon discontinuation of cART, which could be defined as 'functional cure'. Viral reservoirs could provide a persistent source of recrudescent viraemia after withdrawal of cART, despite temporary remission of HIV-1 infection, as observed in the 'Mississippi baby'. Intensification of cART has been proposed as a strategy to control residual replication and to diminish the reservoirs. The effects of cART intensification with maraviroc persisted after discontinuation of the drug in HIV-1-infected adults. However, in HIV-1-infected children, the emergence of CXCR4-using variants occurs very early, and the use of CCR5 antagonists in these children as intensification therapy may not be the best alternative. New treatments to eradicate HIV-1 are focused on the activation of viral production from latently infected cells to purge and clear HIV-1 reservoirs. This strategy involves the use of a wide range of small molecules called latency-reversing agents (LRAs). Histone deacetylase inhibitors (HDACi) such as givinostat, belinostat and panobinostat, and class I-selective HDACis that include oxamflatin, NCH-51 and romidepsin, are the most advanced in clinical testing for HIV-1 LRAs. Panobinostat and romidepsin show an efficient reactivation profile in J89GFP cells, a lymphocyte HIV-1 latently infected cell line considered a relevant model to study post-integration HIV-1 latency and reactivation. Clinical trials with panobinostat and romidepsin have been performed in children with other pathologies and it could be reasonable to design a clinical trial using these drugs in combination with cART in HIV-1-infected children.

  10. Regulatory B cells inhibit cytotoxic T lymphocyte (CTL) activity and elimination of infected CD4 T cells after in vitro reactivation of HIV latent reservoirs.

    PubMed

    Siewe, Basile; Wallace, Jennillee; Rygielski, Sonya; Stapleton, Jack T; Martin, Jeffrey; Deeks, Steven G; Landay, Alan

    2014-01-01

    During HIV infection, IL-10/IL-10 receptor and programmed death-1 (PD-1)/programmed death-1-ligand (PD-L1) interactions have been implicated in the impairment of cytotoxic T lymphocyte (CTL) activity. Despite antiretroviral therapy (ART), attenuated anti-HIV CTL functions present a major hurdle towards curative measures requiring viral eradication. Therefore, deeper understanding of the mechanisms underlying impaired CTL is crucial before HIV viral eradication is viable. The generation of robust CTL activity necessitates interactions between antigen-presenting cells (APC), CD4+ and CD8+ T cells. We have shown that in vitro, IL-10hiPD-L1hi regulatory B cells (Bregs) directly attenuate HIV-specific CD8+-mediated CTL activity. Bregs also modulate APC and CD4+ T cell function; herein we characterize the Breg compartment in uninfected (HIVNEG), HIV-infected "elite controllers" (HIVEC), ART-treated (HIVART), and viremic (HIVvir), subjects, and in vitro, assess the impact of Bregs on anti-HIV CTL generation and activity after reactivation of HIV latent reservoirs using suberoylanilide hydroxamic acid (SAHA). We find that Bregs from HIVEC and HIVART subjects exhibit comparable IL-10 expression levels significantly higher than HIVNEG subjects, but significantly lower than HIVVIR subjects. Bregs from HIVEC and HIVART subjects exhibit comparable PD-L1 expression, significantly higher than in HIVVIR and HIVNEG subjects. SAHA-treated Breg-depleted PBMC from HIVEC and HIVART subjects, displayed enhanced CD4+ T-cell proliferation, significant upregulation of antigen-presentation molecules, increased frequency of CD107a+ and HIV-specific CD8+ T cells, associated with efficient elimination of infected CD4+ T cells, and reduction in integrated viral DNA. Finally, IL-10-R and PD-1 antibody blockade partially reversed Breg-mediated inhibition of CD4+ T-cell proliferation. Our data suggest that, possibly, via an IL-10 and PD-L1 synergistic mechanism; Bregs likely inhibit APC function

  11. Level of herpes simplex virus type 1 latency correlates with severity of corneal scarring and exhaustion of CD8+ T cells in trigeminal ganglia of latently infected mice.

    PubMed

    Mott, Kevin R; Bresee, Catherine J; Allen, Sariah J; BenMohamed, Lbachir; Wechsler, Steven L; Ghiasi, Homayon

    2009-03-01

    A hallmark of infection with herpes simplex virus type 1 (HSV-1) is the establishment of latency in ganglia of the infected individual. During the life of the latently infected individual, the virus can occasionally reactivate, travel back to the eye, and cause recurrent disease. Indeed, a major cause of corneal scarring (CS) is the scarring induced by HSV-1 following reactivation from latency. In this study, we evaluated the relationship between the amount of CS and the level of the HSV-1 latency-associated transcript (LAT) in trigeminal ganglia (TG) of latently infected mice. Our results suggested that the amount of CS was not related to the amount of virus replication following primary ocular HSV-1 infection, since replication in the eyes was similar in mice that did not develop CS, mice that developed CS in just one eye, and mice that developed CS in both eyes. In contrast, mice with no CS had significantly less LAT, and thus presumably less latency, in their TG than mice that had CS in both eyes. Higher CS also correlated with higher levels of mRNAs for PD-1, CD4, CD8, F4/80, interleukin-4, gamma interferon, granzyme A, and granzyme B in both cornea and TG. These results suggest that (i) the immunopathology induced by HSV-1 infection does not correlate with primary virus replication in the eye; (ii) increased CS appears to correlate with increased latency in the TG, although the possible cause-and-effect relationship is not known; and (iii) increased latency in mouse TG correlates with higher levels of PD-1 mRNA, suggesting exhaustion of CD8+ T cells.

  12. Comparison of interferon-γ-, interleukin (IL)-17- and IL-22-expressing CD4 T cells, IL-22-expressing granulocytes and proinflammatory cytokines during latent and active tuberculosis infection.

    PubMed

    Cowan, J; Pandey, S; Filion, L G; Angel, J B; Kumar, A; Cameron, D W

    2012-02-01

    In this study, we investigated the role and expression of T helper type 17 (Th17) cells and Th17 cytokines in human tuberculosis. We show that the basal proportion of interferon (IFN)-γ-, interleukin (IL)-17- and IL-22-expressing CD4(+) T cells and IL-22-expressing granulocytes in peripheral blood were significantly lower in latently infected healthy individuals and active tuberculosis patients compared to healthy controls. In contrast, CD4(+) T cells expressing IL-17, IL-22 and IFN-γ were increased significantly following mycobacterial antigens stimulation in both latent and actively infected patients. Interestingly, proinflammatory IFN-γ and tumour necrosis factor (TNF)-α were increased following antigen stimulation in latent infection. Similarly, IL-1β, IL-4, IL-8, IL-22 and TNF-α were increased in the serum of latently infected individuals, whereas IL-6 and TNF-α were increased significantly in actively infected patients. Overall, we observed differential induction of IL-17-, IL-22- and IFN-γ-expressing CD4(+) T cells, IL-22-expressing granulocytes and proinflammatory cytokines in circulation and following antigenic stimulation in latent and active tuberculosis.

  13. Detection of herpes simplex virus type 2 (HSV-2) -specific cell-mediated immune responses in guinea pigs during latent HSV-2 genital infection.

    PubMed

    Perry, Clarice L; Banasik, Brianne N; Gorder, Summer R; Xia, Jingya; Auclair, Sarah; Bourne, Nigel; Milligan, Gregg N

    2016-12-01

    Genital infections with herpes simplex virus type 2 (HSV-2) are a source of considerable morbidity and are a health concern for newborns exposed to virus during vaginal delivery. Additionally, HSV-2 infection diminishes the integrity of the vaginal epithelium resulting in increased susceptibility of individuals to infection with other sexually transmitted pathogens. Understanding immune protection against HSV-2 primary infection and immune modulation of virus shedding events following reactivation of the virus from latency is important for the development of effective prophylactic and therapeutic vaccines. Although the murine model of HSV-2 infection is useful for understanding immunity following immunization, it is limited by the lack of spontaneous reactivation of HSV-2 from latency. Genital infection of guinea pigs with HSV-2 accurately models the disease of humans including the spontaneous reactivation of HSV-2 from latency and provides a unique opportunity to examine virus-host interactions during latency. Although the guinea pig represents an accurate model of many human infections, relatively few reagents are available to study the immunological response to infection. To analyze the cell-mediated immune response of guinea pigs at extended periods of time after establishment of HSV-2 latency, we have modified flow-cytometry based proliferation assays and IFN-γ ELISPOT assays to detect and quantify HSV-specific cell-mediated responses during latent infection of guinea pigs. Here we demonstrate that a combination of proliferation and ELISPOT assays can be used to quantify and characterize effecter function of virus-specific immune memory responses during HSV-latency.

  14. T cell responses to DosR and Rpf proteins in actively and latently infected individuals from Colombia.

    PubMed

    Riaño, Felipe; Arroyo, Leonar; París, Sara; Rojas, Mauricio; Friggen, Annemieke H; van Meijgaarden, Krista E; Franken, Kees L M C; Ottenhoff, Tom H M; García, Luis F; Barrera, Luis F

    2012-03-01

    Mycobacterium tuberculosis DosR regulon-encoded proteins elicit strong immune T-cell responses in individuals with latent tuberculosis (LTBI). Also, resuscitation (Rpf) proteins can induce such responses. However, variations in the immunogenicity of the DosR and Rpf proteins have been observed in European and African populations, and no data are published from other geographic areas. In Colombian LTBI and patients with recently diagnosed PTB, we therefore studied the immune response to DosR, Rpf, stress, and nominal antigens from Mtb, in 7-day stimulated cultures. Three DosR (Rv1737c, Rv2029c, Rv2628c) and 2 Rpf (Rv0867 and Rv2389c) antigens were recognized most prominently on the basis of the net IFNγ production (DosR) or the percentage of responding individuals (Rpf). Results show that the selected DosR antigens induced a higher proportion of CD4-T cells producing IFNγ from LTBI, compared to pulmonary TB patients (PTB), while there were no differences in the proportion of CD8-T cells. An increased frequency of CD4, but not CD8 T-cells with a CD45RO(+)CD27(+) phenotype was observed in LTBI in response to Rv2029c, Rv0867c, and Rv2389c, compared to PTB. The levels of cytokines and chemokines in the supernatants of stimulated cells, showed that the DosR and Rpf antigens induced higher levels of IFNγ in cultures from LTBI compared to PTB, although the induced pattern of cytokines and chemokines was also antigen dependent. In summary, our results are consistent with the significant immunogenicity of Mtb DosR and Rpf antigens in LTBI individuals, and confirm and extend previously reported data from other TB affected human populations.

  15. KSHV miRNAs decrease expression of lytic genes in latently infected PEL and endothelial cells by targeting host transcription factors.

    PubMed

    Plaisance-Bonstaff, Karlie; Choi, Hong Seok; Beals, Tyler; Krueger, Brian J; Boss, Isaac W; Gay, Lauren A; Haecker, Irina; Hu, Jianhong; Renne, Rolf

    2014-10-23

    Kaposi's sarcoma-associated herpesvirus (KSHV) microRNAs are encoded in the latency-associated region. Knockdown of KSHV miR-K12-3 and miR-K12-11 increased expression of lytic genes in BC-3 cells, and increased virus production from latently infected BCBL-1 cells. Furthermore, iSLK cells infected with miR-K12-3 and miR-K12-11 deletion mutant viruses displayed increased spontaneous reactivation and were more sensitive to inducers of reactivation than cells infected with wild type KSHV. Predicted binding sites for miR-K12-3 and miR-K12-11 were found in the 3'UTRs of the cellular transcription factors MYB, Ets-1, and C/EBPα, which activate RTA, the KSHV replication and transcription activator. Targeting of MYB by miR-K12-11 was confirmed by cloning the MYB 3'UTR downstream from the luciferase reporter. Knockdown of miR‑K12-11 resulted in increased levels of MYB transcript, and knockdown of miR-K12-3 increased both C/EBPα and Ets-1 transcripts. Thus, miR-K12-11 and miR-K12-3 contribute to maintenance of latency by decreasing RTA expression indirectly, presumably via down-regulation of MYB, C/EBPα and Ets-1, and possibly other host transcription factors.

  16. 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.

  17. Human Cytomegalovirus miR-UL148D Facilitates Latent Viral Infection by Targeting Host Cell Immediate Early Response Gene 5

    PubMed Central

    Li, Limin; Li, Donghai; Liu, Fenyong; Zhang, Chen-Yu; Zen, Ke

    2016-01-01

    The mechanisms underlying human cytomegalovirus (HCMV) latency remain incompletely understood. Here, we showed that a HCMV-encoded miRNA, miR-UL148D, robustly accumulates during late stages of experimental latent HCMV infection in host cells and promotes HCMV latency by modulating the immediate early response gene 5 (IER5)-cell division cycle 25B (CDC25B) axis in host cells. miR-UL148D inhibited IER5 expression by directly targeting the three-prime untranslated region(3’UTR) of IER5 mRNA and thus rescued CDC25B expression during the establishment of viral latency. Infection with NR-1ΔmiR-UL148D, a derivative of the HCMV clinical strain NR-1 with a miR-UL148D knockout mutation, resulted in sustained induction of IER5 expression but decreased CDC25B expression in host cells. Mechanistically, we further showed that CDC25B plays an important role in suppressing HCMV IE1 and lytic gene transcription by activating cyclin-dependent kinase 1 (CDK-1). Both gain-of-function and lose-of-function assays demonstrated that miR-UL148D promotes HCMV latency by helping maintain CDC25B activity in host cells. These results provide a novel mechanism through which a HCMV miRNA regulates viral latency. PMID:27824944

  18. 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

  19. 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

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

    PubMed

    Wang, Jianbin; Quake, Stephen R

    2014-09-09

    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.

  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 Effect of Latent Toxoplasma gondii Infection on the Immune Response in HIV-Infected Patients.

    PubMed

    Beran, Ondrej; Kodym, Petr; Maly, Marek; Davidova, Alzbeta; Reinvartova, Gabriela; Jilich, David; Holub, Michal; Rozsypal, Hanus

    2015-01-01

    A relationship between latent toxoplasmosis and the immune system during HIV disease is poorly understood. Therefore, the aim of this follow-up study was to characterize immunological parameters in HIV-infected patients with latent toxoplasmosis and noninfected individuals. A total of 101 HIV-infected patients were enrolled in the study. The patients were classified into two groups based on anti-Toxoplasma gondii antibodies: a group of 55 toxoplasma-positive persons (TP) and a group of 46 toxoplasma-negative persons (TN). Absolute counts of several lymphocyte subsets decreased in the TP group, namely, T cells (p = 0.007), B cells (p = 0.002), NK cells (p = 0.009), CD4 T cells (p = 0.028), and CD8 T cells (p = 0.004). On the other hand, the percentage of CD8 T cells expressing CD38 and HLA-DR significantly increased during the follow-up in the TP group (p = 0.003, p = 0.042, resp.) as well as the intensity of CD38 and HLA-DR expression (MFI) on CD8 T cells (p = 0.001, p = 0.057, resp.). In the TN group, analysis of the kinetics of immunological parameters revealed no significant changes over time. In conclusion, the results suggest that latent T. gondii infection modulates the immune response during HIV infection.

  3. 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

  4. 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

  5. The Herpes Simplex Virus Latency-Associated Transcript Gene Is Associated with a Broader Repertoire of Virus-Specific Exhausted CD8+ T Cells Retained within the Trigeminal Ganglia of Latently Infected HLA Transgenic Rabbits

    PubMed Central

    Srivastava, Ruchi; Dervillez, Xavier; Khan, Arif A.; Chentoufi, Aziz A.; Chilukuri, Sravya; Shukr, Nora; Fazli, Yasmin; Ong, Nicolas N.; Afifi, Rasha E.; Osorio, Nelson; Geertsema, Roger; Nesburn, Anthony B.

    2016-01-01

    ABSTRACT Persistent pathogens, such as herpes simplex virus 1 (HSV-1), have evolved a variety of immune evasion strategies to avoid being detected and destroyed by the host's immune system. A dynamic cross talk appears to occur between the HSV-1 latency-associated transcript (LAT), the only viral gene that is abundantly transcribed during latency, and the CD8+ T cells that reside in HSV-1 latently infected human and rabbit trigeminal ganglia (TG). The reactivation phenotype of TG that are latently infected with wild-type HSV-1 or with LAT-rescued mutant (i.e., LAT+ TG) is significantly higher than TG latently infected with LAT-null mutant (i.e., LAT− TG). Whether LAT promotes virus reactivation by selectively shaping a unique repertoire of HSV-specific CD8+ T cells in LAT+ TG is unknown. In the present study, we assessed the frequency, function, and exhaustion status of TG-resident CD8+ T cells specific to 40 epitopes derived from HSV-1 gB, gD, VP11/12, and VP13/14 proteins, in human leukocyte antigen (HLA-A*0201) transgenic rabbits infected ocularly with LAT+ versus LAT– virus. Compared to CD8+ T cells from LAT– TG, CD8+ T cells from LAT+ TG (i) recognized a broader selection of nonoverlapping HSV-1 epitopes, (ii) expressed higher levels of PD-1, TIM-3, and CTLA-4 markers of exhaustion, and (iii) produced less tumor necrosis factor alpha, gamma interferon, and granzyme B. These results suggest a novel immune evasion mechanism by which the HSV-1 LAT may contribute to the shaping of a broader repertoire of exhausted HSV-specific CD8+ T cells in latently infected TG, thus allowing for increased viral reactivation. IMPORTANCE A significantly larger repertoire of dysfunctional (exhausted) HSV-specific CD8+ T cells were found in the TG of HLA transgenic rabbits latently infected with wild-type HSV-1 or with LAT-rescued mutant (i.e., LAT+ TG) than in a more restricted repertoire of functional HSV-specific CD8+ T cells in the TG of HLA transgenic rabbits latently

  6. The Herpes Simplex Virus Latency-Associated Transcript Gene Is Associated with a Broader Repertoire of Virus-Specific Exhausted CD8+ T Cells Retained within the Trigeminal Ganglia of Latently Infected HLA Transgenic Rabbits.

    PubMed

    Srivastava, Ruchi; Dervillez, Xavier; Khan, Arif A; Chentoufi, Aziz A; Chilukuri, Sravya; Shukr, Nora; Fazli, Yasmin; Ong, Nicolas N; Afifi, Rasha E; Osorio, Nelson; Geertsema, Roger; Nesburn, Anthony B; Wechsler, Steven L; BenMohamed, Lbachir

    2016-04-01

    Persistent pathogens, such as herpes simplex virus 1 (HSV-1), have evolved a variety of immune evasion strategies to avoid being detected and destroyed by the host's immune system. A dynamic cross talk appears to occur between the HSV-1 latency-associated transcript (LAT), the only viral gene that is abundantly transcribed during latency, and the CD8(+)T cells that reside in HSV-1 latently infected human and rabbit trigeminal ganglia (TG). The reactivation phenotype of TG that are latently infected with wild-type HSV-1 or with LAT-rescued mutant (i.e., LAT(+)TG) is significantly higher than TG latently infected with LAT-null mutant (i.e., LAT(-)TG). Whether LAT promotes virus reactivation by selectively shaping a unique repertoire of HSV-specific CD8(+)T cells in LAT(+)TG is unknown. In the present study, we assessed the frequency, function, and exhaustion status of TG-resident CD8(+)T cells specific to 40 epitopes derived from HSV-1 gB, gD, VP11/12, and VP13/14 proteins, in human leukocyte antigen (HLA-A*0201) transgenic rabbits infected ocularly with LAT(+)versus LAT(-)virus. Compared to CD8(+)T cells from LAT(-)TG, CD8(+)T cells from LAT(+)TG (i) recognized a broader selection of nonoverlapping HSV-1 epitopes, (ii) expressed higher levels of PD-1, TIM-3, and CTLA-4 markers of exhaustion, and (iii) produced less tumor necrosis factor alpha, gamma interferon, and granzyme B. These results suggest a novel immune evasion mechanism by which the HSV-1 LAT may contribute to the shaping of a broader repertoire of exhausted HSV-specific CD8(+)T cells in latently infected TG, thus allowing for increased viral reactivation. A significantly larger repertoire of dysfunctional (exhausted) HSV-specific CD8(+)T cells were found in the TG of HLA transgenic rabbits latently infected with wild-type HSV-1 or with LAT-rescued mutant (i.e., LAT(+)TG) than in a more restricted repertoire of functional HSV-specific CD8(+)T cells in the TG of HLA transgenic rabbits latently infected

  7. The immunology of human cytomegalovirus latency: could latent infection be cleared by novel immunotherapeutic strategies?

    PubMed

    Wills, Mark R; Poole, Emma; Lau, Betty; Krishna, Ben; Sinclair, John H

    2015-03-01

    While the host immune response following primary human cytomegalovirus (HCMV) infection is generally effective at stopping virus replication and dissemination, virus is never cleared by the host and like all herpesviruses, persists for life. At least in part, this persistence is known to be facilitated by the ability of HCMV to establish latency in myeloid cells in which infection is essentially silent with, importantly, a total lack of new virus production. However, although the viral transcription programme during latency is much suppressed, a number of viral genes are expressed during latent infection at the protein level and many of these have been shown to have profound effects on the latent cell and its environment. Intriguingly, many of these latency-associated genes are also expressed during lytic infection. Therefore, why the same potent host immune responses generated during lytic infection to these viral gene products are not recognized during latency, thereby allowing clearance of latently infected cells, is far from clear. Reactivation from latency is also a major cause of HCMV-mediated disease, particularly in the immune compromised and immune naive, and is also likely to be a major source of virus in chronic subclinical HCMV infection which has been suggested to be associated with long-term diseases such as atherosclerosis and some neoplasias. Consequently, understanding latency and why latently infected cells appear to be immunoprivileged is crucial for an understanding of the pathogenesis of HCMV and may help to design strategies to eliminate latent virus reservoirs, at least in certain clinical settings.

  8. BCG Re-vaccination of Adults with Latent Mycobacterium tuberculosis Infection Induces Long-lived BCG-Reactive Natural Killer Cell Responses1

    PubMed Central

    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

    2016-01-01

    One third of the global population is estimated to be latently infected with Mycobacterium tuberculosis (M.tb). We performed a phase 1 randomized, controlled trial of isoniazid preventive therapy (IPT) before re-vaccination with Bacille Calmette-Guerin (BCG) in healthy, tuberculin skin test positive (≥15mm induration), HIV-negative, South African adults. We hypothesised that pre-clearance of latent bacilli with IPT modulates BCG immunogenicity following re-vaccination. Frequencies and co-expression of IFNγ, TNFα, IL-2, IL-17, and/or IL-22 in CD4, and IFNγ-expressing CD8, 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 BCG re-vaccinated after IPT (n=33) or without prior IPT (n=39). IPT had little effect on frequencies or cytokine co-expression patterns of M.tb- or BCG-specific responses. Re-vaccination transiently boosted BCG-specific Th1 cytokine-expressing CD4, CD8 and γδ T cells. Despite high frequencies of IFNγ-expressing BCG-reactive CD3+CD56+ NKT-like, CD3−CD56dim and CD3−CD56hi NK cells at baseline, BCG re-vaccination boosted these responses, which remained elevated up to one year after re-vaccination. Such BCG-reactive memory NK cells were induced by BCG vaccination in infants, while in vitro IFN-γ expression by NK cells upon BCG stimulation was dependent on IL-12 and IL-18. Our data suggest that isoniazid pre-clearance of M.tb bacilli has little effect on the magnitude, persistence or functional attributes of lymphocyte responses boosted by BCG re-vaccination. Our study highlights surprising durability of BCG-boosted memory NKT-like and NK cells expressing anti-mycobacterial effector molecules, which may be novel targets for TB vaccines. PMID:27412415

  9. Analysis of cell-to-cell and long-distance movement of apple latent spherical virus in infected plants using green, cyan, and yellow fluorescent proteins.

    PubMed

    Takahashi, Tsubasa; Yoshikawa, Nobuyuki

    2008-01-01

    Apple latent spherical virus (ALSV) expressing green, cyan, and yellow fluorescent proteins (GFP, CFP, and YFP) was constructed and used to analyze the local and systemic movement of the virus in infected plants. In Chenopodium quinoa plants inoculated with GFP-ALSV, the infection foci first appeared as small fluorescent spots 2-3 days post inoculation (dpi). The GFP spots expanded as rings from 5 dpi, then fused to each other, and most fluorescence faded out at 10-12 dpi. In upper uninoculated leaves, GFP fluorescence was first observed 6-7 dpi on the basal area of mature leaves and on the entire area of young developing leaves. The appearance of fluorescent flecks on young leaves was first found on and near the class III and IV veins. ALSV labeled with two different fluorescent proteins (CFP-ALSV and YFP-ALSV) were used to investigate the distribution of identical, but differently labeled viruses in mixed infection. Fluorescence from CFP and YFP was in each case observed in separate areas in both inoculated and upper uninoculated leaves, indicating that populations of identical, but differently labeled viruses were replicated and distributed in discrete areas of infected leaves.

  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. An Upstream YY1 Binding Site on the HIV-1 LTR Contributes to Latent Infection

    PubMed Central

    Bernhard, Wendy; Barreto, Kris; Raithatha, Sheetal; Sadowski, Ivan

    2013-01-01

    During HIV-1 infection a population of latently infected cells is established. This population is the major obstacle preventing total eradication of the virus from AIDS patients. HIV-1 latency is thought to arise by various mechanisms including repressive chromatin modifications. Transcription factors such as YY1 have been shown to facilitate repressive chromatin modifications by the recruitment of histone deacetylases. In this study, we identified a novel binding site for YY1 on the HIV-1 LTR, 120 nucleotides upstream of the transcription start site. We show that YY1 can bind to this site in vitro and in vivo and that binding to the LTR is dissociated upon T cell activation. Overexpression of YY1 causes an increase in the proportion of cells that produce latent infections. These observations, in combination with previous results, demonstrate that YY1 plays a prominent role in controlling the establishment and maintenance of latent HIV-1 provirus in unstimulated cells. PMID:24116200

  12. Human cytomegalovirus latent infection alters the expression of cellular and viral microRNA.

    PubMed

    Fu, Miao; Gao, Yan; Zhou, Qiuju; Zhang, Qi; Peng, Ying; Tian, Kegang; Wang, Jinhua; Zheng, Xiaoqun

    2014-02-25

    MicroRNAs (miRNAs) play important roles in regulating gene expression of plants, animals and viruses. Comprehensive characterization of host and viral miRNA will help uncover the molecular mechanisms that underlie the progression of human cytomegalovirus (HCMV) latent infection. To investigate the miRNA expression profile of HCMV and host cells during latent infection, we performed deep-sequencing analysis of the small RNAs isolated from HCMV-infected and mock-infected human monocytic leukemia cell line, THP-1. We established a HCMV latent infection cell model using the THP-1 cells. High-throughput sequencing technology was used to sequence small RNA libraries of the HCMV-infected and mock-infected THP-1 and to investigate their small RNA transcriptomes. We found eight miRNAs including miR-US25-1, miR-US25-2-5p and miR-UL112 that were expressed by HCMV during latent infection. The expressions of the host miRNAs were also affected by HCMV latent infection. At least 49 cellular miRNAs were differentially expressed: 39 were up-regulated and 10 were down-regulated upon HCMV latent infection. The expression of the human miRNA hsa-miR-124-3p was significantly up-regulated in the HCMV latent infection library. In addition, we found 14 cellular novel miRNAs in the HCMV-infected and mock-infected THP-1 libraries. Functional annotation of the target genes of the differentially expressed miRNAs suggested that the majority of the genes are involved in melanogenesis, pathways in cancer, endocytosis and wnt signaling pathway. The small RNA transcriptomes obtained in this study demonstrate the usefulness of the deep-sequencing combined with bioinformatics approach in understanding of the expression and function of host and viral small RNAs in HCMV latent infection. This approach can also be applied to the study of other kinds of viruses. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Persistently elevated T cell interferon-γ responses after treatment for latent tuberculosis infection among health care workers in India: a preliminary report

    PubMed Central

    Pai, Madhukar; Joshi, Rajnish; Dogra, Sandeep; Mendiratta, Deepak K; Narang, Pratibha; Dheda, Keertan; Kalantri, Shriprakash

    2006-01-01

    Background T cell-based interferon-γ (IFN-γ) release assays (IGRAs) are novel tests for latent tuberculosis infection (LTBI). It has been suggested that T cell responses may be correlated with bacterial burden and, therefore, IGRAs may have a role in monitoring treatment response. We investigated IFN-γ responses to specific TB antigens among Indian health care workers (HCWs) before, and after LTBI preventive therapy. Methods In 2004, we established a cohort of HCWs who underwent tuberculin skin testing (TST) and a whole-blood IGRA (QuantiFERON-TB-Gold In-Tube [QFT-G], Cellestis Ltd, Victoria, Australia) at a rural hospital in India. HCWs positive by either test were offered 6 months of isoniazid (INH) preventive therapy. Among the HCWs who underwent therapy, we prospectively followed-up 10 nursing students who were positive by both tests at baseline. The QFT-G assay was repeated 4 and 10 months after INH treatment completion (i.e. approximately 12 months and 18 months after the initial testing). IFN-γ responses to ESAT-6, CFP-10 and TB7.7 peptides were measured using ELISA, and IFN-γ ≥0.35 IU/mL was used to define a positive QFT-G test result. Results All participants (N = 10) reported direct contact with smear-positive TB patients at baseline, during and after LTBI treatment. All participants except one started treatment with high baseline IFN-γ responses (median 10.0 IU/mL). The second QFT-G was positive in 9 of 10 participants, but IFN-γ responses had declined (median 5.0 IU/mL); however, this difference was not significant (P = 0.10). The third QFT-G assay continued to be positive in 9 of 10 participants, with persistently elevated IFN-γ responses (median 7.9 IU/mL; P = 0.32 for difference against baseline average). Conclusion In an environment with ongoing, intensive nosocomial exposure, HCWs had strong IFN-γ responses at baseline, and continued to have persistently elevated responses, despite LTBI treatment. It is plausible that persistence of

  14. 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

  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 Central

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

    2014-01-01

    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. 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

  17. Transcriptional profiling of Marek's disease virus genes during cytolytic and latent infection

    USDA-ARS?s Scientific Manuscript database

    Marek’s disease (MD), a lymphoproliferative disease of chicken is caused by a highly cell-associated alpha-herpesvirus, Marek’s disease virus (MDV). MDV replicates in chicken lymphocytes and establishes a latent infection within CD4+ T cells. The expression analysis of limited viral transcripts ha...

  18. T cells increase before zoster and PD-1 expression increases at the time of zoster in immunosuppressed nonhuman primates latently infected with simian varicella virus.

    PubMed

    James, Stephanie F; Traina-Dorge, Vicki; Deharo, Eileen; Wellish, Mary; Palmer, Brent E; Gilden, Don; Mahalingam, Ravi

    2014-06-01

    Like varicella zoster virus in humans, simian varicella virus (SVV) becomes latent in ganglionic neurons along the entire neuraxis and reactivates in immunosuppressed monkeys. Five rhesus macaques were inoculated with SVV; 142 days later (latency), four monkeys were immunosuppressed, and T cells were analyzed for naïve, memory, and effector phenotypes and expression of programmed death receptor-1 (PD-1; T cell exhaustion). All T cell subsets decreased during immunosuppression and except for CD8 effectors, peaked 2 weeks before zoster. Compared to before immunosuppression, PD-1 expression increased at reactivation. Increased T cells before zoster is likely due to virus reactivation.

  19. Host-pathogen interactions in latent Mycobacterium tuberculosis infection: identification of new targets for tuberculosis intervention.

    PubMed

    Lin, May Young; Ottenhoff, Tom H M

    2008-03-01

    Mycobacterium tuberculosis (M. tuberculosis) is one of the worlds' most successful and sophisticated pathogens. It is estimated that over 2 billion people today harbour latent M. tuberculosis infection without any clinical symptoms. Since most new cases of active tuberculosis (TB) arise from this (growing) number of latently infected individuals, urgent measures to control TB reactivation are required, including more effective drugs and new TB vaccines. The currently widely used BCG vaccines, as well as most new generation TB-vaccines that are being developed are designed as prophylactic or as BCG-booster vaccines. Unfortunately, many of these vaccines are unlikely to be effective in individuals already latently infected with M. tuberculosis. Here we argue that detailed analysis of M. tuberculosis genes that are switched on predominantly during the latent stage of infection may lead to the identification of new M. tuberculosis targets for drug and vaccine development. First, we will describe essential host-pathogen interactions in TB with particular emphasis on TB latency and persistent infection. Subsequently, we will focus on a novel group of late-stage specific genes, encoded by the M. tuberculosis dormancy (dosR) regulon, and summarize recent studies describing human T-cell recognition of these dormancy antigens in relation to (latent) M. tuberculosis infection. We will discuss the possible relevance of these new classes of antigens for new TB intervention strategies.

  20. 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

  1. The immunology of human cytomegalovirus latency: could latent infection be cleared by novel immunotherapeutic strategies?

    PubMed Central

    Wills, Mark R; Poole, Emma; Lau, Betty; Krishna, Ben; Sinclair, John H

    2015-01-01

    While the host immune response following primary human cytomegalovirus (HCMV) infection is generally effective at stopping virus replication and dissemination, virus is never cleared by the host and like all herpesviruses, persists for life. At least in part, this persistence is known to be facilitated by the ability of HCMV to establish latency in myeloid cells in which infection is essentially silent with, importantly, a total lack of new virus production. However, although the viral transcription programme during latency is much suppressed, a number of viral genes are expressed during latent infection at the protein level and many of these have been shown to have profound effects on the latent cell and its environment. Intriguingly, many of these latency-associated genes are also expressed during lytic infection. Therefore, why the same potent host immune responses generated during lytic infection to these viral gene products are not recognized during latency, thereby allowing clearance of latently infected cells, is far from clear. Reactivation from latency is also a major cause of HCMV-mediated disease, particularly in the immune compromised and immune naive, and is also likely to be a major source of virus in chronic subclinical HCMV infection which has been suggested to be associated with long-term diseases such as atherosclerosis and some neoplasias. Consequently, understanding latency and why latently infected cells appear to be immunoprivileged is crucial for an understanding of the pathogenesis of HCMV and may help to design strategies to eliminate latent virus reservoirs, at least in certain clinical settings. PMID:25132454

  2. Identification of T cell-signaling pathways that stimulate latent HIV in primary cells

    PubMed Central

    Brooks, David G.; Arlen, Philip A.; Gao, Lianying; Kitchen, Christina M. R.; Zack, Jerome A.

    2003-01-01

    Eradication of HIV infection depends on the elimination of a small, but stable population of latently infected T cells. After the discontinuation of therapy, activation of latent virus can rekindle infection. To purge this reservoir, it is necessary to define cellular signaling pathways that lead to activation of latent HIV. We used the SCID-hu (Thy/Liv) mouse model of HIV latency to analyze a broad array of T cell-signaling pathways and show in primary, quiescent cells that viral induction depends on the activation of two primary intracellular signaling pathways, protein kinase C or nuclear factor of activated T cells (NF-AT). In contrast, inhibition or activation of other important T cell stimulatory pathways (such as mitogen-activated protein kinase, calcium flux, or histone deacetylation) do not significantly induce virus expression. We found that the activation of NF-κB is critical to viral reactivation; however, all pathways that stimulate NF-κBdonot reactivate latent virus. Our studies further show that inhibition of NF-κB does not prevent activation of HIV by NF-AT, indicating that these pathways can function independently to activate the HIV LTR. Thus, we define several molecular pathways that trigger HIV reactivation from latency and provide evidence that latent HIV infection is maintained by the functional lack of particular transcription factors in quiescent cells. PMID:14569007

  3. Epstein-Barr Virus: The Path from Latent to Productive Infection.

    PubMed

    Chiu, Ya-Fang; Sugden, Bill

    2016-09-29

    The intrinsic properties of different viruses have driven their study. For example, the capacity for efficient productive infection of cultured cells by herpes simplex virus 1 has made it a paradigm for this mode of infection for herpesviruses in general. Epstein-Barr virus, another herpesvirus, has two properties that have driven its study: It causes human cancers, and it exhibits a tractable transition from its latent to its productive cycle in cell culture. Here, we review our understanding of the path Epstein-Barr virus follows to move from a latent infection to and through its productive cycle. We use information from human infections to provide a framework for describing studies in cell culture and, where possible, the molecular resolutions from these studies. We also pose questions whose answers we think are pivotal to understanding this path, and we provide answers where we can.

  4. 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.

  5. Comparison of the QuantiFERON-TB Gold In-Tube test with the tuberculin skin test for detecting latent tuberculosis infection prior to hematopoietic stem cell transplantation.

    PubMed

    Moon, S M; Lee, S-O; Choi, S-H; Kim, Y S; Woo, J H; Yoon, D H; Suh, C; Kim, D-Y; Lee, J-H; Lee, Je-H; Lee, K-H; Kim, S-H

    2013-02-01

    A total of 244 patients including 100 (41%) autologous hematopoietic stem cell transplant (HCT) recipients and 144 (59%) allogeneic HCT recipients were enrolled over a 28-month period. During the study period, no prophylaxis for latent tuberculosis (TB) infection was administrated. Of these, 201 (82%) had Bacillus Calmette-Guérin (BCG) scars or prior histories of BCG vaccination. The tuberculin skin test (TST) and the QuantiFERON-TB Gold In-Tube (QFT-GIT) test were performed simultaneously in all 244 patients. TST indurations were ≥ 5 mm in 39 of these patients (15%), and in 25 (10%) indurations were ≥ 10 mm. In addition, 40 (16%) had positive QFT-GIT outcomes, and 34 (14%) indeterminate outcomes. If the 34 patients with indeterminate QFT-GIT results were excluded from the overall agreement analysis, the agreement between the TST results (induration size ≥ 5 mm) and the QFT-GIT results in the 210 patients with clear QFT results was poor (κ = 0.08, 95% confidence interval [CI] -0.06 to 0.24), as it was for the patients with indurations ≥ 10 mm (κ = 0.15, 95% CI -0.004 to 0.31). During follow up, 2 patients developed TB after HCT. The incidence of TB in the patients with positive QFT-GIT outcomes was 2.80 per 100 person-years (95% CI 0.07-15.81), whereas among those with positive TST (≥ 5 mm) results, it was 0 per 100 person-years (95% CI 0-8.00). However, this finding should be cautiously interpreted because of the relatively short follow up and the fact that the sample size of the study cohort did not have adequate power. In conclusion, our data show that, although the frequencies of positive outcomes in the 2 TB screening tests were similar, the overall agreement between the TST and the QFT-GIT test was poor, regardless of BCG vaccination history.

  6. 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

  7. Syphilis superinfection activates expression of human immunodeficiency virus I in latently infected rabbits.

    PubMed Central

    Tseng, C. K.; Hughes, M. A.; Hsu, P. L.; Mahoney, S.; Duvic, M.; Sell, S.

    1991-01-01

    Superinfection of latently human immunodeficiency virus (HIV)-infected rabbits with either Treponema pallidum or Shope fibroma virus (SFV) activates HIV expression. In addition, HIV-infected rabbits demonstrate prolonged cutaneous lesions (chancres) after intracutaneous challenge with T. pallidum, the causative agent of syphilis. Rabbits were infected by intravenous inoculation of 3 x 10(7) human T-cell lymphotrophic virus type III (HTLV-III)/B10 (HIV-1)-infected H9 (human) cells. Five weeks after initial infection, integrated HIV-1-specific DNA sequences were detected in the DNA of the peripheral blood lymphocytes of only one of eight rabbits using polymerase chain reactions (PCR); human DNA could not be detected at this time. Furthermore HIV infection could not be demonstrated by either seroconversion or PCR during the next 6 months. All HIV-infected rabbits remained clinically healthy and had normal white blood cell counts. Six months after HIV infection, four HIV-infected and two noninfected controls were superinfected with 10(6) T. pallidum in eight skin sites in the shaved skin of the back, and four infected and two control animals were challenged with an intradermal injection with SFV. After infection with either syphilis or SFV, the DNA from the white blood cells of all eight HIV-infected rabbits contained HIV sequences, and HIV sequences were demonstrated in dermal mononuclear cells of the syphilitic lesions by in situ hybridization. The SFV-induced tumors were rejected normally in the HIV-infected rabbits, but four of the four rabbits challenged with T. pallidum had delayed development of cutaneous lesions and three of four demonstrated larger and more prolonged lesions. White blood counts, mitogen responses, and interleukin-2 production remained within normal limits, and seroconversion for HIV was not detected. Three of four rabbits in a second group, challenged with T. pallidum 4 months after HIV-inoculation, also had delayed healing of syphilitic

  8. Bryostatin modulates latent HIV-1 infection via PKC and AMPK signaling but inhibits acute infection in a receptor independent manner.

    PubMed

    Mehla, Rajeev; Bivalkar-Mehla, Shalmali; Zhang, Ruonan; Handy, Indhira; Albrecht, Helmut; Giri, Shailendra; Nagarkatti, Prakash; Nagarkatti, Mitzi; Chauhan, Ashok

    2010-06-16

    HIV's ability to establish long-lived latent infection is mainly due to transcriptional silencing in resting memory T lymphocytes and other non dividing cells including monocytes. Despite an undetectable viral load in patients treated with potent antiretrovirals, current therapy is unable to purge the virus from these latent reservoirs. In order to broaden the inhibitory range and effectiveness of current antiretrovirals, the potential of bryostatin was investigated as an HIV inhibitor and latent activator. Bryostatin revealed antiviral activity against R5- and X4-tropic viruses in receptor independent and partly via transient decrease in CD4/CXCR4 expression. Further, bryostatin at low nanomolar concentrations robustly reactivated latent viral infection in monocytic and lymphocytic cells via activation of Protein Kinase C (PKC) -alpha and -delta, because PKC inhibitors rottlerin and GF109203X abrogated the bryostatin effect. Bryostatin specifically modulated novel PKC (nPKC) involving stress induced AMP Kinase (AMPK) inasmuch as an inhibitor of AMPK, compound C partially ablated the viral reactivation effect. Above all, bryostatin was non-toxic in vitro and was unable to provoke T-cell activation. The dual role of bryostatin on HIV life cycle may be a beneficial adjunct to the treatment of HIV especially by purging latent virus from different cellular reservoirs such as brain and lymphoid organs.

  9. Bryostatin Modulates Latent HIV-1 Infection via PKC and AMPK Signaling but Inhibits Acute Infection in a Receptor Independent Manner

    PubMed Central

    Zhang, Ruonan; Handy, Indhira; Albrecht, Helmut; Giri, Shailendra; Nagarkatti, Prakash; Nagarkatti, Mitzi; Chauhan, Ashok

    2010-01-01

    HIV's ability to establish long-lived latent infection is mainly due to transcriptional silencing in resting memory T lymphocytes and other non dividing cells including monocytes. Despite an undetectable viral load in patients treated with potent antiretrovirals, current therapy is unable to purge the virus from these latent reservoirs. In order to broaden the inhibitory range and effectiveness of current antiretrovirals, the potential of bryostatin was investigated as an HIV inhibitor and latent activator. Bryostatin revealed antiviral activity against R5- and X4-tropic viruses in receptor independent and partly via transient decrease in CD4/CXCR4 expression. Further, bryostatin at low nanomolar concentrations robustly reactivated latent viral infection in monocytic and lymphocytic cells via activation of Protein Kinase C (PKC) -α and -δ, because PKC inhibitors rottlerin and GF109203X abrogated the bryostatin effect. Bryostatin specifically modulated novel PKC (nPKC) involving stress induced AMP Kinase (AMPK) inasmuch as an inhibitor of AMPK, compound C partially ablated the viral reactivation effect. Above all, bryostatin was non-toxic in vitro and was unable to provoke T-cell activation. The dual role of bryostatin on HIV life cycle may be a beneficial adjunct to the treatment of HIV especially by purging latent virus from different cellular reservoirs such as brain and lymphoid organs. PMID:20585398

  10. Microarray analysis in the HSV-1 latently infected mouse trigeminal ganglion.

    PubMed

    Higaki, Shiro; Deai, Tatsunori; Fukuda, Masahiko; Shimomura, Yoshikazu

    2004-11-01

    drugs compared with untreated latent mice. These genes were peripheral myelin protein 22, decorin, transcription factor AP-1, dystroglycan 1, myelin protein zero, mitogen-activated protein kinase 3, prothymosin beta4, and brain lipid-binding protein. The results obtained by semiquantitative RT-PCR results were similar to those obtained by microarray analysis. Six hours after heat stress, the genes whose expression was altered included the FK506-binding protein gene (decreased), the T-complex protein 1alpha subunit gene (increased), and the 94-kDa glucose-regulated protein gene (increased in uninfected TG, decreased in infected TG). Heat stress increased expression of the DNA excision repair protein ERCC5 gene 24 hours after the treatment. Genes previously reported to exhibit increased transcription 1 hour after heat stress did not continue to show significant transcriptional activation at 6 or 24 hours. Those genes whose expression is altered by immunosuppressive drug treatment may play an important role in ocular HSV-1 recurrence. Changes in gene expression in the prostaglandin pathway, a transcription factor, and an enzyme in the cell cycle are considered of special importance for HSV-1 reactivation by immunosuppression. Altered gene expression at 6 and 24 hours after heat stress was different from previously reported changes in gene expression 1 hour after hyperthermia in HSV-1 latently infected mice.

  11. The Herpes Simplex Virus 1 Latency-Associated Transcript Promotes Functional Exhaustion of Virus-Specific CD8+ T Cells in Latently Infected Trigeminal Ganglia: a Novel Immune Evasion Mechanism▿

    PubMed Central

    Chentoufi, Aziz A.; Kritzer, Elizabeth; Tran, Michael V.; Dasgupta, Gargi; Lim, Chang Hyun; Yu, David C.; Afifi, Rasha E.; Jiang, Xianzhi; Carpenter, Dale; Osorio, Nelson; Hsiang, Chinhui; Nesburn, Anthony B.; Wechsler, Steven L.; BenMohamed, Lbachir

    2011-01-01

    Following ocular herpes simplex virus 1 (HSV-1) infection of C57BL/6 mice, HSV-specific (HSV-gB498–505 tetramer+) CD8+ T cells are induced, selectively retained in latently infected trigeminal ganglia (TG), and appear to decrease HSV-1 reactivation. The HSV-1 latency-associated transcript (LAT) gene, the only viral gene that is abundantly transcribed during latency, increases reactivation. Previously we found that during latency with HSV-1 strain McKrae-derived viruses, more of the total TG resident CD8 T cells expressed markers of exhaustion with LAT+ virus compared to LAT− virus. Here we extend these findings to HSV-1 strain 17syn+-derived LAT+ and LAT− viruses and to a virus expressing just the first 20% of LAT. Thus, the previous findings were not an artifact of HSV-1 strain McKrae, and the LAT function involved mapped to the first 1.5 kb of LAT. Importantly, to our knowledge, we show here for the first time that during LAT+ virus latency, most of the HSV-1-specific TG resident CD8 T cells were functionally exhausted, as judged by low cytotoxic function and decreased gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) production. This resulted in LAT− TG having more functional HSV-gB498–505 tetramer+ CD8+ T cells compared to LAT+ TG. In addition, LAT expression, in the absence of other HSV-1 gene products, appeared to be able to directly or indirectly upregulate both PD-L1 and major histocompatibility complex class I (MHC-I) on mouse neuroblastoma cells (Neuro2A). These findings may constitute a novel immune evasion mechanism whereby the HSV-1 LAT directly or indirectly promotes functional exhaustion (i.e., dysfunction) of HSV-specific CD8+ T cells in latently infected TG, resulting in increased virus reactivation. PMID:21715478

  12. Integrated systems biology analysis of KSHV latent infection reveals viral induction and reliance on peroxisome mediated lipid metabolism

    PubMed Central

    Sychev, Zoi E.; Hu, Alex; Lagunoff, Michael

    2017-01-01

    Kaposi’s Sarcoma associated Herpesvirus (KSHV), an oncogenic, human gamma-herpesvirus, is the etiological agent of Kaposi’s Sarcoma the most common tumor of AIDS patients world-wide. KSHV is predominantly latent in the main KS tumor cell, the spindle cell, a cell of endothelial origin. KSHV modulates numerous host cell-signaling pathways to activate endothelial cells including major metabolic pathways involved in lipid metabolism. To identify the underlying cellular mechanisms of KSHV alteration of host signaling and endothelial cell activation, we identified changes in the host proteome, phosphoproteome and transcriptome landscape following KSHV infection of endothelial cells. A Steiner forest algorithm was used to integrate the global data sets and, together with transcriptome based predicted transcription factor activity, cellular networks altered by latent KSHV were predicted. Several interesting pathways were identified, including peroxisome biogenesis. To validate the predictions, we showed that KSHV latent infection increases the number of peroxisomes per cell. Additionally, proteins involved in peroxisomal lipid metabolism of very long chain fatty acids, including ABCD3 and ACOX1, are required for the survival of latently infected cells. In summary, novel cellular pathways altered during herpesvirus latency that could not be predicted by a single systems biology platform, were identified by integrated proteomics and transcriptomics data analysis and when correlated with our metabolomics data revealed that peroxisome lipid metabolism is essential for KSHV latent infection of endothelial cells. PMID:28257516

  13. Integrated systems biology analysis of KSHV latent infection reveals viral induction and reliance on peroxisome mediated lipid metabolism.

    PubMed

    Sychev, Zoi E; Hu, Alex; DiMaio, Terri A; Gitter, Anthony; Camp, Nathan D; Noble, William S; Wolf-Yadlin, Alejandro; Lagunoff, Michael

    2017-03-01

    Kaposi's Sarcoma associated Herpesvirus (KSHV), an oncogenic, human gamma-herpesvirus, is the etiological agent of Kaposi's Sarcoma the most common tumor of AIDS patients world-wide. KSHV is predominantly latent in the main KS tumor cell, the spindle cell, a cell of endothelial origin. KSHV modulates numerous host cell-signaling pathways to activate endothelial cells including major metabolic pathways involved in lipid metabolism. To identify the underlying cellular mechanisms of KSHV alteration of host signaling and endothelial cell activation, we identified changes in the host proteome, phosphoproteome and transcriptome landscape following KSHV infection of endothelial cells. A Steiner forest algorithm was used to integrate the global data sets and, together with transcriptome based predicted transcription factor activity, cellular networks altered by latent KSHV were predicted. Several interesting pathways were identified, including peroxisome biogenesis. To validate the predictions, we showed that KSHV latent infection increases the number of peroxisomes per cell. Additionally, proteins involved in peroxisomal lipid metabolism of very long chain fatty acids, including ABCD3 and ACOX1, are required for the survival of latently infected cells. In summary, novel cellular pathways altered during herpesvirus latency that could not be predicted by a single systems biology platform, were identified by integrated proteomics and transcriptomics data analysis and when correlated with our metabolomics data revealed that peroxisome lipid metabolism is essential for KSHV latent infection of endothelial cells.

  14. Brain Macrophages in Simian Immunodeficiency Virus-Infected, Antiretroviral-Suppressed Macaques: a Functional Latent Reservoir.

    PubMed

    Avalos, Claudia R; Abreu, Celina M; Queen, Suzanne E; Li, Ming; Price, Sarah; Shirk, Erin N; Engle, Elizabeth L; Forsyth, Ellen; Bullock, Brandon T; Mac Gabhann, Feilim; Wietgrefe, Stephen W; Haase, Ashley T; Zink, M Christine; Mankowski, Joseph L; Clements, Janice E; Gama, Lucio

    2017-08-15

    A human immunodeficiency virus (HIV) infection cure requires an understanding of the cellular and anatomical sites harboring virus that contribute to viral rebound upon treatment interruption. Despite antiretroviral therapy (ART), HIV-associated neurocognitive disorders (HAND) are reported in HIV-infected individuals on ART. Biomarkers for macrophage activation and neuronal damage in cerebrospinal fluid (CSF) of HIV-infected individuals demonstrate continued effects of HIV in brain and suggest that the central nervous system (CNS) may serve as a viral reservoir. Using a simian immunodeficiency virus (SIV)/macaque model for HIV encephalitis and AIDS, we evaluated whether infected cells persist in brain despite ART. Eight SIV-infected pig-tailed macaques were virally suppressed with ART, and plasma and CSF viremia levels were analyzed longitudinally. To assess whether virus persisted in brain macrophages (BrMΦ) in these macaques, we used a macrophage quantitative viral outgrowth assay (MΦ-QVOA), PCR, and in situ hybridization (ISH) to measure the frequency of infected cells and the levels of viral RNA and DNA in brain. Viral RNA in brain tissue of suppressed macaques was undetectable, although viral DNA was detected in all animals. The MΦ-QVOA demonstrated that the majority of suppressed animals contained latently infected BrMΦ. We also showed that virus produced in the MΦ-QVOAs was replication competent, suggesting that latently infected BrMΦ are capable of reestablishing productive infection upon treatment interruption. This report provides the first confirmation of the presence of replication-competent SIV in BrMΦ of ART-suppressed macaques and suggests that the highly debated issue of viral latency in macrophages, at least in brain, has been addressed in SIV-infected macaques treated with ART.IMPORTANCE Resting CD4(+) T cells are currently the only cells that fit the definition of a latent reservoir. However, recent evidence suggests that HIV/SIV-infected

  15. Vpx-containing Dendritic Cell Vaccine Vectors Induce CTLs and Reactivate Latent HIV-1 in vitro

    PubMed Central

    Norton, Thomas D.; Miller, Elizabeth A.; Bhardwaj, Nina; Landau, Nathaniel R.

    2015-01-01

    Eradication of HIV-1 from an infected individual requires a means of inducing production of virus from latently infected cells and stimulating an immune response against the infected cells. We report the development of lentiviral vectors that transduce dendritic cells (DCs) to both induce production of virus from latently infected cells and stimulate antigen-specific CTLs. The vectors package Vpx, a lentiviral accessory protein that counteracts the SAMHD1-mediated block to DC transduction, allowing for long-term expression of vector-encoded proteins. The vectors encode influenza or HIV-1-derived epitopes fused via a self-cleaving peptide to CD40L that releases the peptide into the endoplasmic reticulum for entry into the antigen presentation pathway. Expression of CD40L caused transduced DCs to mature and produce Th1-skewing cytokines. The DCs presented antigen to CD8 T cells, enhancing antigen-specific CTLs. Coculture of the transduced DCs with latently infected cells induced high level virus production, an effect that was mediated by TNF-α. The ability of a DC vaccine to reactivate latent HIV-1 and stimulate an adaptive immune response provides a means to reduce the size of the latent reservoir in patients. This strategy can also be applied to develop DC vaccines for other diseases. PMID:25567537

  16. Dendritic cell type-specific HIV-1 activation in effector T cells: implications for latent HIV-1 reservoir establishment.

    PubMed

    van der Sluis, Renée M; van Capel, Toni M M; Speijer, Dave; Sanders, Rogier W; Berkhout, Ben; de Jong, Esther C; Jeeninga, Rienk E; van Montfort, Thijs

    2015-06-01

    Latent HIV type I (HIV-1) infections can frequently occur in short-lived proliferating effector T lymphocytes. These latently infected cells could revert into resting T lymphocytes and thereby contribute to the establishment of the long-lived viral reservoir. Monocyte-derived dendritic cells can revert latency in effector T cells in vitro. Here we investigated the latency activation properties of tissue-specific immune cells, including a large panel of dendritic cell subsets, to explore in which body compartments effector T cells are most likely to maintain latent HIV-1 provirus and thus potentially contribute to the long-lived reservoir. Our results demonstrate that blood or genital tract dendritic cells do not activate latent provirus in effector T cells, whereas gut or lymphoid dendritic cells induce virus production from latently infected effector T cells in our in-vitro model for latency. Toll-like receptor 3-induced interferon production by myeloid dendritic cells abolished the dendritic cells' ability to induce viral gene expression. In this study, we show that HIV-1 provirus residing in effector T cells is activated from latency by tissue-specific dendritic cell subsets and other immune cells with remarkably different efficiencies.Our new assay system points to an important, neglected aspect of HIV-1 research: the ability of other immune cells, especially dendritic cells, to differentially affect latency establishment as well as virus reactivation.

  17. 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

  18. Blockage of CD59 Function Restores Activities of Neutralizing and Nonneutralizing Antibodies in Triggering Antibody-Dependent Complement-Mediated Lysis of HIV-1 Virions and Provirus-Activated Latently Infected Cells

    PubMed Central

    Yang, Kai; Lan, Jie; Shepherd, Nicole; Hu, Ningjie; Xing, Yanyan; Byrd, Daniel; Amet, Tohti; Jewell, Corlin; Gupta, Samir; Kounga, Carole

    2015-01-01

    ABSTRACT Both HIV-1 virions and infected cells use their surface regulators of complement activation (RCA) to resist antibody-dependent complement-mediated lysis (ADCML). Blockage of the biological function of RCA members, particularly CD59 (a key RCA member that controls formation of the membrane attack complex at the terminal stage of the complement activation cascades via all three activation pathways), has rendered both HIV-1 virions and infected cells sensitive to ADCML mediated by anti-Env antibodies (Abs) or sera/plasma from patients at different stages of viral infection. In the current study, we used the well-characterized anti-HIV-1 neutralizing Abs (nAbs), including 2G12, 2F5, and 4E10, and non-nAbs, including 2.2C, A32, N5-i5, and N12-i15, to investigate whether the enhancement of ADCML by blockage of CD59 function is mediated by nAbs, non-nAbs, or both. We found that all nAbs and two non-nAbs (N5-i5 and A32) strongly reacted to three HIV-1 laboratory strains (R5, X4, and R5/X4), six primary isolates, and provirus-activated ACH-2 cells examined. In contrast, two non-nAbs, 2.2C and N12-i15, reacted weakly and did not react to these targets, respectively. After blockage of CD59 function, the reactive Abs, regardless of their neutralizing activities, significantly enhanced specific ADCML of HIV-1 virions (both laboratory strains and primary isolates) and provirus-activated latently infected cells. The ADMCL efficacy positively correlated with the enzyme-linked immunosorbent assay-reactive intensity of those Abs with their targets. Thus, blockage of RCA function represents a novel approach to restore activities of both nAbs and non-nAbs in triggering ADCML of HIV-1 virions and provirus-activated latently infected cells. IMPORTANCE There is a renewed interest in the potential role of non-nAbs in the control of HIV-1 infection. Our data, for the first time, demonstrated that blockage of the biological function of RCA members rendered both HIV-1 virions and

  19. Blockage of CD59 Function Restores Activities of Neutralizing and Nonneutralizing Antibodies in Triggering Antibody-Dependent Complement-Mediated Lysis of HIV-1 Virions and Provirus-Activated Latently Infected Cells.

    PubMed

    Yang, Kai; Lan, Jie; Shepherd, Nicole; Hu, Ningjie; Xing, Yanyan; Byrd, Daniel; Amet, Tohti; Jewell, Corlin; Gupta, Samir; Kounga, Carole; Gao, Jimin; Yu, Qigui

    2015-09-01

    Both HIV-1 virions and infected cells use their surface regulators of complement activation (RCA) to resist antibody-dependent complement-mediated lysis (ADCML). Blockage of the biological function of RCA members, particularly CD59 (a key RCA member that controls formation of the membrane attack complex at the terminal stage of the complement activation cascades via all three activation pathways), has rendered both HIV-1 virions and infected cells sensitive to ADCML mediated by anti-Env antibodies (Abs) or sera/plasma from patients at different stages of viral infection. In the current study, we used the well-characterized anti-HIV-1 neutralizing Abs (nAbs), including 2G12, 2F5, and 4E10, and non-nAbs, including 2.2C, A32, N5-i5, and N12-i15, to investigate whether the enhancement of ADCML by blockage of CD59 function is mediated by nAbs, non-nAbs, or both. We found that all nAbs and two non-nAbs (N5-i5 and A32) strongly reacted to three HIV-1 laboratory strains (R5, X4, and R5/X4), six primary isolates, and provirus-activated ACH-2 cells examined. In contrast, two non-nAbs, 2.2C and N12-i15, reacted weakly and did not react to these targets, respectively. After blockage of CD59 function, the reactive Abs, regardless of their neutralizing activities, significantly enhanced specific ADCML of HIV-1 virions (both laboratory strains and primary isolates) and provirus-activated latently infected cells. The ADMCL efficacy positively correlated with the enzyme-linked immunosorbent assay-reactive intensity of those Abs with their targets. Thus, blockage of RCA function represents a novel approach to restore activities of both nAbs and non-nAbs in triggering ADCML of HIV-1 virions and provirus-activated latently infected cells. There is a renewed interest in the potential role of non-nAbs in the control of HIV-1 infection. Our data, for the first time, demonstrated that blockage of the biological function of RCA members rendered both HIV-1 virions and infected cells

  20. Mexican immigrants' explanatory model of latent tuberculosis infection.

    PubMed

    McEwen, Marylyn M

    2005-10-01

    This article reveals how the multiple and disparate explanations of latent tuberculosis infection (LTBI) from the U.S. and Mexico professional health sectors and the popular sector are used to inform the explanatory model (EM) of LTBI for Mexican immigrants residing in the U.S.-Mexico border region. Fourteen immigrants, nine diagnosed with LTBI (n = 9) and their spouses (n = 5) participated in this critical ethnographic study. Because care seeking and treatment decisions are influenced by EMs, the results indicate that it is imperative that interventions for Mexican immigrants with LTBI are built on an understanding of their illness experience and are contextually meaningful.

  1. 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

  2. Proteomic Profiling of EBNA1-Host Protein Interactions in Latent and Lytic Epstein-Barr Virus Infections

    PubMed Central

    Malik-Soni, Natasha

    2012-01-01

    The Epstein-Barr nuclear antigen 1 (EBNA1) protein of Epstein-Barr virus (EBV) is expressed in both latent and lytic modes of EBV infection and contributes to EBV-associated cancers. Using a proteomics approach, we profiled EBNA1-host protein interactions in nasopharyngeal and gastric carcinoma cells in the context of latent and lytic EBV infection. We identified several interactions that occur in both modes of infection, including a previously unreported interaction with nucleophosmin and RNA-mediated interactions with several heterogeneous ribonucleoproteins (hnRNPs) and La protein. PMID:22496234

  3. Proteomic profiling of EBNA1-host protein interactions in latent and lytic Epstein-Barr virus infections.

    PubMed

    Malik-Soni, Natasha; Frappier, Lori

    2012-06-01

    The Epstein-Barr nuclear antigen 1 (EBNA1) protein of Epstein-Barr virus (EBV) is expressed in both latent and lytic modes of EBV infection and contributes to EBV-associated cancers. Using a proteomics approach, we profiled EBNA1-host protein interactions in nasopharyngeal and gastric carcinoma cells in the context of latent and lytic EBV infection. We identified several interactions that occur in both modes of infection, including a previously unreported interaction with nucleophosmin and RNA-mediated interactions with several heterogeneous ribonucleoproteins (hnRNPs) and La protein.

  4. 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

  5. Epidemiology of cyprinid herpesvirus-3 infection in latently infected carp from aquaculture.

    PubMed

    Baumer, A; Fabian, M; Wilkens, M R; Steinhagen, D; Runge, M

    2013-07-22

    Cyprinid herpesvirus-3 (CyHV-3, koi herpesvirus, KHV) is the causative agent of an economically important disease in carp. The mode of transmission of this virus, especially how the infectious agent is introduced into ponds de novo, is not known in detail. The aim of this study was to investigate the shedding of CyHV-3 from fish with latent infections, under aquaculture conditions. Ponds in Saxony, Germany, with latently infected carp were examined at different times during the production cycle to investigate the influence of fish farming procedures on virus activation and shedding. Carp and water samples were investigated by quantitative real-time PCR. Some of the latently infected carp shed CyHV-3. Virus shedding was induced mainly when the ponds were drained and the carp either harvested or moved to different ponds, and was independent of the water temperature. This indicated that during these times there was a risk that effluent water from the ponds could disseminate the infectious agent. During summer, on-growing carp are infected with low numbers of CyHV-3. These findings are important for disease management strategies in carp aquaculture and for the design of testing protocols for the detection of latent infection in carp populations.

  6. Latent Mycobacterium tuberculosis Infection and Interferon-Gamma Release Assays.

    PubMed

    Pai, Madhukar; Behr, Marcel

    2016-10-01

    The identification of individuals with latent tuberculosis infection (LTBI) is useful for both fundamental understanding of the pathogenesis of disease and for clinical and public health interventions (i.e., to prevent progression to disease). Basic research suggests there is a pathogenetic continuum from exposure to infection to disease, and individuals may advance or reverse positions within the spectrum, depending on changes in the host immunity. Unfortunately, there is no diagnostic test that resolves the various stages within the spectrum of Mycobacterium tuberculosis infection. Two main immune-based approaches are currently used for identification of LTBI: the tuberculin skin test (TST) and the interferon-gamma release assay (IGRA). TST can use either the conventional purified protein derivative or more specific antigens. Extensive research suggests that both TST and IGRA represent indirect markers of M. tuberculosis exposure and indicates a cellular immune response to M. tuberculosis. The imperfect concordance between these two tests suggests that neither test is perfect, presumably due to both technical and biological reasons. Neither test can accurately differentiate between LTBI and active TB. Both IGRA and TST have low sensitivity in a variety of immunocompromised populations. Cohort studies have shown that both TST and IGRA have low predictive value for progression from infection to active TB. For fundamental applications, basic research is necessary to identify those at highest risk of disease with a positive TST and/or IGRA. For clinical applications, the identification of such biomarkers can help prioritize efforts to interrupt progression to disease through preventive therapy.

  7. 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.

  8. Varicella-zoster virus transcriptome in latently infected human ganglia.

    PubMed

    Nagel, Maria A; Choe, Alexander; Traktinskiy, Igor; Cordery-Cotter, Robert; Gilden, Don; Cohrs, Randall J

    2011-03-01

    We recently developed a novel multiplex reverse transcription (RT)-PCR assay that allows rapid and sensitive detection of transcripts corresponding to all 68 unique varicella-zoster virus (VZV) open reading frames (ORFs) in only five amplification reactions (M. A. Nagel, D. Gilden, T. Shade, B. Gao, and R. J. Cohrs, J. Virol. Methods 157:62-68, 2009). Herein, we applied multiplex RT-PCR analysis to mRNA extracted from 26 trigeminal ganglia latently infected with VZV and one control trigeminal ganglion negative for VZV DNA that were removed from 14 men and women, 16 to 84 years of age, within 24 h after death. Analysis identified VZV transcripts mapping to VZV ORFs 29, 62, and 63, previously detected and sequence verified; VZV ORFs 4 and 40, previously detected by in situ hybridization; and VZV ORFs 11, 41, 43, 57, and 68, not previously detected. VZV ORF 63 transcripts were the most prevalent. Comparison of the 10 VZV ORFs transcribed during latency to their herpes simplex virus type 1 homologues reveals that the latently transcribed VZV genes encode immediate-early, early, and late transcripts.

  9. RNA-directed gene editing specifically eradicates latent and prevents new HIV-1 infection.

    PubMed

    Hu, Wenhui; Kaminski, Rafal; Yang, Fan; Zhang, Yonggang; Cosentino, Laura; Li, Fang; Luo, Biao; Alvarez-Carbonell, David; Garcia-Mesa, Yoelvis; Karn, Jonathan; Mo, Xianming; Khalili, Kamel

    2014-08-05

    AIDS remains incurable due to the permanent integration of HIV-1 into the host genome, imparting risk of viral reactivation even after antiretroviral therapy. New strategies are needed to ablate the viral genome from latently infected cells, because current methods are too inefficient and prone to adverse off-target effects. To eliminate the integrated HIV-1 genome, we used the Cas9/guide RNA (gRNA) system, in single and multiplex configurations. We identified highly specific targets within the HIV-1 LTR U3 region that were efficiently edited by Cas9/gRNA, inactivating viral gene expression and replication in latently infected microglial, promonocytic, and T cells. Cas9/gRNAs caused neither genotoxicity nor off-target editing to the host cells, and completely excised a 9,709-bp fragment of integrated proviral DNA that spanned from its 5' to 3' LTRs. Furthermore, the presence of multiplex gRNAs within Cas9-expressing cells prevented HIV-1 infection. Our results suggest that Cas9/gRNA can be engineered to provide a specific, efficacious prophylactic and therapeutic approach against AIDS.

  10. Management of tuberculosis and latent tuberculosis infection in human immunodeficiency virus-infected persons.

    PubMed

    Lee, Shui Shan; Meintjes, Graeme; Kamarulzaman, Adeeba; Leung, Chi Chiu

    2013-08-01

    The syndemic of human immunodeficiency virus (HIV)/tuberculosis (TB) co-infection has grown as a result of the considerable sociogeographic overlaps between the two epidemics. The situation is particularly worrisome in countries with high or intermediate TB burden against the background of a variable HIV epidemic state. Early diagnosis of TB disease in an HIV-infected person is paramount but suffers from lack of sensitive and specific diagnostic tools. Enhanced symptom screening is currently advocated, and the wide application of affordable molecular diagnostics is urgently needed. Treatment of TB/HIV co-infection involves the concurrent use of standard antiretrovirals and antimycobacterials during which harmful drug interaction may occur. The pharmacokinetic interaction between rifamycin and antiretrovirals is a case in point, requiring dosage adjustment and preferential use of rifabutin, if available. Early initiation of antiretroviral therapy is indicated, preferably at 2 weeks after starting TB treatment for patients with a CD4 of <50 cells/μL. Development of TB-immune reconstitution inflammatory syndrome (TB-IRIS) is however more frequent with early antiretroviral therapy. The diagnosis of TB-IRIS is another clinical challenge, and cautious use of corticosteroids is suggested to improve clinical outcome. As a preventive measure against active TB disease, the screening for latent TB infection should be widely practiced, followed by at least 6-9 months of isoniazid treatment. To date tuberculin skin test remains the only diagnostic tool in high TB burden countries. The role of alternative tests, for example, interferon-γ release assay, would need to be better defined for clinical application.

  11. 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

  12. [Prevalence of latent tuberculosis infection amongst immigrants entering prison].

    PubMed

    Solé, N; Marco, A; Escribano, M; Orcau, A; Quintero, S; Del Baño, L; Caylà, J A

    2012-01-01

    To study the prevalence of latent tuberculosis infection (LTBI) and the predictive factors amongst immigrants entering prison. prospective study conducted in May and June of 2009. The tuberculin skin test (TST) was performed, with induration of ≥ 10 mm being regarded as positive. Variables collected were: age, origin, number of incarcerations, length of time living in Spain, heroin and cocaine consumption, intravenous drug use and HIV infection. The rate of LTBI was calculated and the overall infection rate (ITL and history of TB). To study predictable factors, a bivariant and multivariant analysis were carried out using logistic regression. 152 male immigrants. Average age: 31.9 years ± 7.8; 37.2% of them with heroin or cocaine consumption and 7.5% IDU. 12 patients were previously TST positive and 6 patients had history of TB. TST was performed on 134 people, 63 with positive results and 71 with negative ones. ITL rate: 49.3. Overall infection rate: 53.3%. Bivariate associated with LTBI: more than one incarceration (67.4% vs. 36.4% in primary, p=0.001), age (76% ≥ 40 vs. 40.4% under this age and heroin and cocaine consumption (60% consumers vs. 39.3% non consumers; p=0.02. Multivariate analysis only confirmed the association with age (p=0.001; OR: 2.34, IC=1.39-3.94). The LTBI rate amongst immigrants entering prison is very high. A complete study is recommended for all of them, with special attention being paid to the most vulnerable ones, such as older people.

  13. Prevalence of latent Mycobacterium tuberculosis infection in prisoners

    PubMed Central

    de Navarro, Pedro Daibert; de Almeida, Isabela Neves; Kritski, Afrânio Lineu; Ceccato, Maria das Graças; Maciel, Mônica Maria Delgado; Carvalho, Wânia da Silva; de Miranda, Silvana Spindola

    2016-01-01

    ABSTRACT Objective: To determine the prevalence of and the factors associated with latent Mycobacterium tuberculosis infection (LTBI) in prisoners in the state of Minas Gerais, Brazil. Methods: This was a cross-sectional cohort study conducted in two prisons in Minas Gerais. Tuberculin skin tests were performed in the individuals who agreed to participate in the study. Results: A total of 1,120 individuals were selected for inclusion in this study. The prevalence of LTBI was 25.2%. In the multivariate analysis, LTBI was associated with self-reported contact with active tuberculosis patients within prisons (adjusted OR = 1.51; 95% CI: 1.05-2.18) and use of inhaled drugs (adjusted OR = 1.48; 95% CI: 1.03-2.13). Respiratory symptoms were identified in 131 (11.7%) of the participants. Serological testing for HIV was performed in 940 (83.9%) of the participants, and the result was positive in 5 (0.5%). Two cases of active tuberculosis were identified during the study period. Conclusions: Within the prisons under study, the prevalence of LTBI was high. In addition, LTBI was associated with self-reported contact with active tuberculosis patients and with the use of inhaled drugs. Our findings demonstrate that it is necessary to improve the conditions in prisons, as well as to introduce strategies, such as chest X-ray screening, in order to detect tuberculosis cases and, consequently, reduce M. tuberculosis infection within the prison system. PMID:27812634

  14. Latent herpes simplex virus infection of sensory neurons alters neuronal gene expression.

    PubMed

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

    2003-09-01

    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. (33)P-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.

  15. 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

  16. Persistent expression of chemokine and chemokine receptor RNAs at primary and latent sites of herpes simplex virus 1 infection

    PubMed Central

    Cook, W James; Kramer, Martha F; Walker, Russell M; Burwell, Timothy J; Holman, Holly A; Coen, Donald M; Knipe, David M

    2004-01-01

    Inflammatory cytokines and infiltrating T cells are readily detected in herpes simplex virus (HSV) infected mouse cornea and trigeminal ganglia (TG) during the acute phase of infection, and certain cytokines continue to be expressed at lower levels in infected TG during the subsequent latent phase. Recent results have shown that HSV infection activates Toll-like receptor signaling. Thus, we hypothesized that chemokines may be broadly expressed at both primary sites and latent sites of HSV infection for prolonged periods of time. Real-time reverse transcriptase-polymrease chain reaction (RT-PCR) to quantify expression levels of transcripts encoding chemokines and their receptors in cornea and TG following corneal infection. RNAs encoding the inflammatory-type chemokine receptors CCR1, CCR2, CCR5, and CXCR3, which are highly expressed on activated T cells, macrophages and most immature dendritic cells (DC), and the more broadly expressed CCR7, were highly expressed and strongly induced in infected cornea and TG at 3 and 10 days postinfection (dpi). Elevated levels of these RNAs persisted in both cornea and TG during the latent phase at 30 dpi. RNAs for the broadly expressed CXCR4 receptor was induced at 30 dpi but less so at 3 and 10 dpi in both cornea and TG. Transcripts for CCR3 and CCR6, receptors that are not highly expressed on activated T cells or macrophages, also appeared to be induced during acute and latent phases; however, their very low expression levels were near the limit of our detection. RNAs encoding the CCR1 and CCR5 chemokine ligands MIP-1α, MIP-1β and RANTES, and the CCR2 ligand MCP-1 were also strongly induced and persisted in cornea and TG during the latent phase. These and other recent results argue that HSV antigens or DNA can stimulate expression of chemokines, perhaps through activation of Toll-like receptors, for long periods of time at both primary and latent sites of HSV infection. These chemokines recruit activated T cells and other

  17. Persistent expression of chemokine and chemokine receptor RNAs at primary and latent sites of herpes simplex virus 1 infection.

    PubMed

    Cook, W James; Kramer, Martha F; Walker, Russell M; Burwell, Timothy J; Holman, Holly A; Coen, Donald M; Knipe, David M

    2004-09-23

    Inflammatory cytokines and infiltrating T cells are readily detected in herpes simplex virus (HSV) infected mouse cornea and trigeminal ganglia (TG) during the acute phase of infection, and certain cytokines continue to be expressed at lower levels in infected TG during the subsequent latent phase. Recent results have shown that HSV infection activates Toll-like receptor signaling. Thus, we hypothesized that chemokines may be broadly expressed at both primary sites and latent sites of HSV infection for prolonged periods of time. Real-time reverse transcriptase-polymrease chain reaction (RT-PCR) to quantify expression levels of transcripts encoding chemokines and their receptors in cornea and TG following corneal infection. RNAs encoding the inflammatory-type chemokine receptors CCR1, CCR2, CCR5, and CXCR3, which are highly expressed on activated T cells, macrophages and most immature dendritic cells (DC), and the more broadly expressed CCR7, were highly expressed and strongly induced in infected cornea and TG at 3 and 10 days postinfection (dpi). Elevated levels of these RNAs persisted in both cornea and TG during the latent phase at 30 dpi. RNAs for the broadly expressed CXCR4 receptor was induced at 30 dpi but less so at 3 and 10 dpi in both cornea and TG. Transcripts for CCR3 and CCR6, receptors that are not highly expressed on activated T cells or macrophages, also appeared to be induced during acute and latent phases; however, their very low expression levels were near the limit of our detection. RNAs encoding the CCR1 and CCR5 chemokine ligands MIP-1alpha, MIP-1beta and RANTES, and the CCR2 ligand MCP-1 were also strongly induced and persisted in cornea and TG during the latent phase. These and other recent results argue that HSV antigens or DNA can stimulate expression of chemokines, perhaps through activation of Toll-like receptors, for long periods of time at both primary and latent sites of HSV infection. These chemokines recruit activated T cells and

  18. Latent M. tuberculosis infection--pathogenesis, diagnosis, treatment and prevention strategies.

    PubMed

    Druszczyńska, Magdalena; Kowalewicz-Kulbat, Magdalena; Fol, Marek; Włodarczyk, Marcin; Rudnicka, Wiesława

    2012-01-01

    One third of the earths population is infected with Mycobacterium tuberculosis (Mtb), but only 5-10% of the infected individuals develop active tuberculosis (TB) over their lifetime. The remaining 90-95% stay healthy and are called latently infected individuals. They are the biggest reservoir of the tubercle bacilli and identifying the cases of latent TB is a part of the global plan of TB control. From the clinical point of view detection of latent TB infections (LTBI) in individuals with the highest active TB risk including cases of HIV infection, autoimmune inflammatory diseases or cancer, is a priority. This review summarizes the recent findings in the pathogenesis of latent TB, its diagnosis, treatment and prevention.

  19. 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

  20. Detection of Mycobacterium tuberculosis in latently infected lungs by immunohistochemistry and confocal microscopy

    PubMed Central

    Eugenin, Eliseo; Kaplan, Gilla

    2014-01-01

    Detection of latent Mycobacterium tuberculosis is a challenge in the diagnosis of asymptomatic, subclinical tuberculosis. We report the development of an immunofluorescence technique to visualize and enumerate M. tuberculosis in latently infected rabbit lungs where no acid-fast–stained organisms were seen and no cultivable bacilli were obtained by the agar-plating method. PMID:25161200

  1. 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

  2. Completion of screening for latent tuberculosis infection among immigrants.

    PubMed Central

    Carvalho, A. C. C.; Saleri, N.; El-Hamad, I.; Tedoldi, S.; Capone, S.; Pezzoli, M. C.; Zaccaria, M.; Pizzocolo, A.; Scarcella, C.; Matteelli, A.

    2005-01-01

    The objective of our study was to evaluate the sociodemographic factors associated with completion of screening for latent tuberculosis infection (LTBI) among undocumented immigrants in Brescia, Italy. Screening for LTBI was offered to 649 immigrants; 213 (33%) immigrants completed the first step of screening; only 44% (55/124) of individuals with a positive tuberculin skin test result started treatment for LTBI. The univariate analysis showed that being unmarried, of Senegalese nationality and being interviewed by a health-care worker with the same native language as the immigrant were significantly associated with completion of screening for LTBI. In the multiple logistic regression, being interviewed in the native language of the health-care worker (OR 2.5, 95% CI 1.3-4.8, P = 0.004) and being of Senegalese origin (OR 2.3, 95% CI 1.4-3.6, P = 0.0005) were independently associated with adherence to LTBI screening. Our results suggest that knowledge of the sociodemographic characteristics of immigrants, and the participation of health-care workers of the same cultural origin as the immigrant during the visits, can be an important tool to improve completion of screening for LTBI. PMID:15724725

  3. Substantial molecular evolution and mutation rates in prolonged latent Mycobacterium tuberculosis infection in humans.

    PubMed

    Lillebaek, Troels; Norman, Anders; Rasmussen, Erik Michael; Marvig, Rasmus L; Folkvardsen, Dorte Bek; Andersen, Åse Bengård; Jelsbak, Lars

    2016-11-01

    The genome of Mycobacterium tuberculosis (Mtb) of latently infected individuals may hold the key to understanding the processes that lead to reactivation and progression to clinical disease. We report here analysis of pairs of Mtb isolates from putative prolonged latent TB cases. We identified two confirmed cases, and used whole genome sequencing to investigate the mutational processes that occur over decades in latent Mtb. We found an estimated mutation rate between 0.2 and 0.3 over 33 years, suggesting that latent Mtb accumulates mutations at rates similar to observations from cases of active disease.

  4. Gamma interferon expression during acute and latent nervous system infection by herpes simplex virus type 1.

    PubMed Central

    Cantin, E M; Hinton, D R; Chen, J; Openshaw, H

    1995-01-01

    This study was initiated to evaluate a role for gamma interferon (IFN-gamma) in herpes simplex virus type 1 (HSV-1) infection. At the acute stage of infection in mice, HSV-1 replication in trigeminal ganglia and brain stem tissue was modestly but consistently enhanced in mice from which IFN-gamma was by ablated monoclonal antibody treatment and in mice genetically lacking the IFN-gamma receptor (Rgko mice). As determined by reverse transcriptase PCR, IFN-gamma and tumor necrosis factor alpha transcripts were present in trigeminal ganglia during both acute and latent HSV-1 infection. CD4+ and CD8+ T cells were detected initially in trigeminal ganglia at day 5 after HSV-1 inoculation, and these cells persisted for 6 months into latency. The T cells were focused around morphologically normal neurons that showed no signs of active infection, but many of which expressed HSV-1 latency-associated transcripts. Secreted IFN-gamma was present up to 6 months into latency in areas of the T-cell infiltration. By 9 months into latency, both the T-cell infiltrate and IFN-gamma expression had cleared, although there remained a slight increase in macrophage levels in trigeminal ganglia. In HSV-1-infected brain stem tissue, T cells and IFN-gamma expression were present at 1 month but were gone by 6 months after infection. Our hypothesis is that the persistence of T cells and the sustained IFN-gamma expression occur in response to an HSV-1 antigen(s) in the nervous system. This hypothesis is consistent with a new model of HSV-1 latency which suggests that limited HSV-1 antigen expression occurs during latency (M. Kosz-Vnenchak, J. Jacobson, D.M. Coen, and D.M. Knipe, J. Virol. 67:5383-5393, 1993). We speculate that prolonged secretion of IFN-gamma during latency may modulate a reactivated HSV-1 infection. PMID:7609058

  5. 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

  6. 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

  7. Ranunculus latent virus: a strain of artichoke latent virus or a new macluravirus infecting artichoke?

    PubMed

    Ciuffo, M; Testa, M; Lenzi, R; Turina, M

    2011-06-01

    An elongated virus was isolated from artichoke crops in Liguria, and a 700-bp fragment was amplified by RT-PCR using oligonucleotides to detect members of the family Potyviridae. Comparison of fragment sequences showed 98% identity at the nucleotide level with the ranunculus isolate of the macluravirus Ranunculus latent virus (RaLV). RaLV was then detected by DAS-ELISA in symptomatic and asymptomatic artichoke plants from Liguria, Sardinia and Latium. The sequence of a 5.5-kb region was assembled from a cDNA library, and a 500-bp NIa fragment showed 80% identity to Artichoke latent virus.

  8. Gene-expression reversal of lncRNAs and associated mRNAs expression in active vs latent HIV infection

    PubMed Central

    Nair, Madhavan; Sagar, Vidya; Pilakka-Kanthikeel, Sudheesh

    2016-01-01

    Interplay between lncRNAs and mRNAs is rapidly emerging as a key epigenetic mechanism in controlling various cell functions. HIV can actively infect and/or can persist latently for years by manipulating host epigenetics; however, its molecular essence remains undiscovered in entirety. Here for the first time, we delineate the influence of HIV on global lncRNAs expression in monocytic cells lines. Our analysis revealed the expression modulation of nearly 1060 such lncRNAs which are associated with differentially expressed mRNAs in active and latent infection. This suggests a greater role of lncRNAs in regulating transcriptional and post-transcriptional gene expression during HIV infection. The differentially expressed mRNAs were involved in several different biological pathways where immunological networks were most enriched. Importantly, we discovered that HIV induces expression reversal of more than 150 lncRNAs between its active and latent infection. Also, hundreds of unique lncRNAs were identified in both infection conditions. The pathology specific “gene-expression reversal” and “on-and-off” switching of lncRNAs and associated mRNAs may lead to establish the relationship between active and HIV infection. PMID:27756902

  9. 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.

  10. 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

  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.

  12. Homeostatically Maintained Resting Naive CD4+ T Cells Resist Latent HIV Reactivation

    PubMed Central

    Tsunetsugu-Yokota, Yasuko; Kobayahi-Ishihara, Mie; Wada, Yamato; Terahara, Kazutaka; Takeyama, Haruko; Kawana-Tachikawa, Ai; Tokunaga, Kenzo; Yamagishi, Makoto; Martinez, Javier P.; Meyerhans, Andreas

    2016-01-01

    Homeostatic proliferation (HSP) is a major mechanism by which long-lived naïve and memory CD4+ T cells are maintained in vivo and suggested to contribute to the persistence of the latent HIV-1 reservoir. However, while many in vitro latency models rely on CD4+ T cells that were initially differentiated via T-cell receptor (TCR) stimulation into memory/effector cells, latent infection of naïve resting CD4+ T cells maintained under HSP conditions has not been fully addressed. Here, we describe an in vitro HSP culture system utilizing the cytokines IL-7 and IL-15 that allows studying latency in naïve resting CD4+ T cells. CD4+ T cells isolated from several healthy donors were infected with HIV pseudotypes expressing GFP and cultured under HSP conditions or TCR conditions as control. Cell proliferation, phenotype, and GFP expression were analyzed by flow cytometry. RNA expression was quantified by qRT-PCR. Under HSP culture conditions, latently HIV-1 infected naïve cells are in part maintained in the non-dividing (= resting) state. Although a few HIV-1 provirus+ cells were present in these resting GFP negative cells, the estimated level of GFP transcripts per infected cell seems to indicate a block at the post-transcriptional level. Interestingly, neither TCR nor the prototypic HDAC inhibitor SAHA were able to reactivate HIV-1 provirus from these cells. This lack of reactivation was not due to methylation of the HIV LTR. These results point to a mechanism of HIV control in HSP-cultured resting naïve CD4+ T cells that may be distinct from that in TCR-stimulated memory/effector T cells. PMID:27990142

  13. Two epithelial tumor cell lines (HNE-1 and HONE-1) latently infected with Epstein-Barr virus that were derived from nasopharyngeal carcinomas

    SciTech Connect

    Glaser, R.; Zhang, Haizhang ); Yao, Kaitai; Zhu, Hecheng; Wang, Fuxi; Li, Guiyuan; Wen, Dongseng; Li, Yingping )

    1989-12-01

    Two epithelia tumor cell lines were established from biopsy specimens of nasopharyngeal carcinomas (NPC). The specimens were taken from poorly differentiated squamous cell carcinomas of the nasopharynx. The tissues were prepared for cell culture and eventually two continuous epithelia cell lines were obtained and designated HONE-1 and HNE-1. Light and electron microscopic examination of these two cell lines demonstrated cells with an epithelial morphology including the presence of desmosomes. It was found that early-passage uncloned HNE-1 cells (passage 23) could be superinfected with B95-8 and NPC-EBV isolates as demonstrated by the induction of Epstein-Barr virus (EBV)-specific early antigen(s) in a small percentage of the cells; HONE-1 cells could also be superinfected with EBV. Southern blot analysis detected EBV DNA in samples from uncloned HNE-1 cells at passages 12, 17, 21, 27, and 35. However, by passage 45, EBV DNA could no longer be detected in HNE-1 cells by Southern blot analysis. The EBV genome was detected in parental HONE-1 cells at subculture 9 and in clone 40 cells up to passage 40 thus far. The data suggest that EBV genome-positive HNE-1 and HONE-1 cells were lost as the cells were cultivated in vitro and that cloning the cells at an early passage level may be critical in maintaining EBV genome-positive epithelial NPC cells. These EBV genome-positive epithelia NPC cell lines will be useful for studying the association of EBV and NPC.

  14. Prevalence of latent Mycobacterium tuberculosis infection in prisoners.

    PubMed

    Navarro, Pedro Daibert de; Almeida, Isabela Neves de; Kritski, Afrânio Lineu; Ceccato, Maria das Graças; Maciel, Mônica Maria Delgado; Carvalho, Wânia da Silva; Miranda, Silvana Spindola de

    2016-01-01

    To determine the prevalence of and the factors associated with latent Mycobacterium tuberculosis infection (LTBI) in prisoners in the state of Minas Gerais, Brazil. This was a cross-sectional cohort study conducted in two prisons in Minas Gerais. Tuberculin skin tests were performed in the individuals who agreed to participate in the study. A total of 1,120 individuals were selected for inclusion in this study. The prevalence of LTBI was 25.2%. In the multivariate analysis, LTBI was associated with self-reported contact with active tuberculosis patients within prisons (adjusted OR = 1.51; 95% CI: 1.05-2.18) and use of inhaled drugs (adjusted OR = 1.48; 95% CI: 1.03-2.13). Respiratory symptoms were identified in 131 (11.7%) of the participants. Serological testing for HIV was performed in 940 (83.9%) of the participants, and the result was positive in 5 (0.5%). Two cases of active tuberculosis were identified during the study period. Within the prisons under study, the prevalence of LTBI was high. In addition, LTBI was associated with self-reported contact with active tuberculosis patients and with the use of inhaled drugs. Our findings demonstrate that it is necessary to improve the conditions in prisons, as well as to introduce strategies, such as chest X-ray screening, in order to detect tuberculosis cases and, consequently, reduce M. tuberculosis infection within the prison system. Determinar a prevalência e os fatores associados à infecção latente por Mycobacterium tuberculosis (ILTB) em pessoas privadas de liberdade no Estado de Minas Gerais. Estudo de coorte transversal realizado em duas penitenciárias em Minas Gerais. Foi realizada a prova tuberculínica nos indivíduos que aceitaram participar do estudo. Foram selecionados 1.120 indivíduos para a pesquisa. A prevalência da ILTB foi de 25,2%. Na análise multivariada, a ILTB esteve associada com relato de contato com caso de tuberculose ativa dentro da penitenciária (OR ajustada = 1,51; IC95%: 1

  15. 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 ...

  16. Three months of rifapentine and isoniazid for latent tuberculosis infection.

    PubMed

    Sterling, Timothy R; Villarino, M Elsa; Borisov, Andrey S; Shang, Nong; Gordin, Fred; Bliven-Sizemore, Erin; Hackman, Judith; Hamilton, Carol Dukes; Menzies, Dick; Kerrigan, Amy; Weis, Stephen E; Weiner, Marc; Wing, Diane; Conde, Marcus B; Bozeman, Lorna; Horsburgh, C Robert; Chaisson, Richard E

    2011-12-08

    Treatment of latent Mycobacterium tuberculosis infection is an essential component of tuberculosis control and elimination. The current standard regimen of isoniazid for 9 months is efficacious but is limited by toxicity and low rates of treatment completion. We conducted an open-label, randomized noninferiority trial comparing 3 months of directly observed once-weekly therapy with rifapentine (900 mg) plus isoniazid (900 mg) (combination-therapy group) with 9 months of self-administered daily isoniazid (300 mg) (isoniazid-only group) in subjects at high risk for tuberculosis. Subjects were enrolled from the United States, Canada, Brazil, and Spain and followed for 33 months. The primary end point was confirmed tuberculosis, and the noninferiority margin was 0.75%. In the modified intention-to-treat analysis, tuberculosis developed in 7 of 3986 subjects in the combination-therapy group (cumulative rate, 0.19%) and in 15 of 3745 subjects in the isoniazid-only group (cumulative rate, 0.43%), for a difference of 0.24 percentage points. Rates of treatment completion were 82.1% in the combination-therapy group and 69.0% in the isoniazid-only group (P<0.001). Rates of permanent drug discontinuation owing to an adverse event were 4.9% in the combination-therapy group and 3.7% in the isoniazid-only group (P=0.009). Rates of investigator-assessed drug-related hepatotoxicity were 0.4% and 2.7%, respectively (P<0.001). The use of rifapentine plus isoniazid for 3 months was as effective as 9 months of isoniazid alone in preventing tuberculosis and had a higher treatment-completion rate. Long-term safety monitoring will be important. (Funded by the Centers for Disease Control and Prevention; PREVENT TB ClinicalTrials.gov number, NCT00023452.).

  17. Latent Toxoplasma gondii Infection and Associated Risk Factors among HIV-Infected Individuals at Arba Minch Hospital, South Ethiopia

    PubMed Central

    2014-01-01

    Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii (T. gondii). The parasite has cosmopolitan distribution, infecting almost all species of warm-blooded animals. Latent T. gondii infection in HIV/AIDS patients is a risk for development of cerebral toxoplasmosis (CT). The aim of this study is to determine seroprevalence of latent T. gondii infection and assess its associated factors among individuals infected with HIV in Arba Minch Hospital, south Ethiopia. A facility-based cross-sectional study involving 170 HIV-infected individuals attending Arba Minch Hospital antiretroviral therapy (ART) clinic was conducted from April to June 2013. Data on demographic profile of the study participants and factors associated with T. gondii infection were gathered using a questionnaire. Serum was tested for IgG anti-T. gondii antibody by enzyme-linked immunosorbent assay (ELISA). Data were analyzed using SPSS version 20 software. Seroprevalence of latent T. gondii infection among the study participants was 88.2%. Consumption of raw meat (AOR = 4.361; 95% CI: 1.409–13.496) and involvement in farming/gardening activities (AOR = 4.051; 95% CI: 1.112–14.758) were independent predictors of T. gondii seropositivity. This study revealed high prevalence of latent T. gondii infection, similar to other studies. Monitoring of the patients to prevent reactivation of the latent T. gondii infection is recommended. PMID:25431660

  18. Latent Toxoplasma gondii Infection and Associated Risk Factors among HIV-Infected Individuals at Arba Minch Hospital, South Ethiopia.

    PubMed

    Yohanes, Tsegaye; Debalke, Serkadis; Zemene, Endalew

    2014-01-01

    Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii (T. gondii). The parasite has cosmopolitan distribution, infecting almost all species of warm-blooded animals. Latent T. gondii infection in HIV/AIDS patients is a risk for development of cerebral toxoplasmosis (CT). The aim of this study is to determine seroprevalence of latent T. gondii infection and assess its associated factors among individuals infected with HIV in Arba Minch Hospital, south Ethiopia. A facility-based cross-sectional study involving 170 HIV-infected individuals attending Arba Minch Hospital antiretroviral therapy (ART) clinic was conducted from April to June 2013. Data on demographic profile of the study participants and factors associated with T. gondii infection were gathered using a questionnaire. Serum was tested for IgG anti-T. gondii antibody by enzyme-linked immunosorbent assay (ELISA). Data were analyzed using SPSS version 20 software. Seroprevalence of latent T. gondii infection among the study participants was 88.2%. Consumption of raw meat (AOR = 4.361; 95% CI: 1.409-13.496) and involvement in farming/gardening activities (AOR = 4.051; 95% CI: 1.112-14.758) were independent predictors of T. gondii seropositivity. This study revealed high prevalence of latent T. gondii infection, similar to other studies. Monitoring of the patients to prevent reactivation of the latent T. gondii infection is recommended.

  19. Upregulation of class I major histocompatibility complex gene expression in primary sensory neurons, satellite cells, and Schwann cells of mice in response to acute but not latent herpes simplex virus infection in vivo

    PubMed Central

    1994-01-01

    Major histocompatibility complex (MHC) deficiency is typical of almost all resident cells in normal neural tissue. However, CD8+ T cells, which recognize antigenic peptides in the context of class I MHC molecules, are known to mediate clearance of herpes simplex virus (HSV) from spinal ganglia of experimentally infected mice, leading to the hypothesis that class I expression in the peripheral nervous system must be upregulated in response to HSV infection. In addressing this hypothesis it is shown, in BALB/c (H-2d) mice, that normally deficient class I transcripts transiently accumulate in peripheral nerve Schwann cells, ganglionic satellite cells, and primary sensory neurons, indicating that in each of these cell types class I expression is regulated at the transcriptional level in vivo. Furthermore, for 3-4 wk after infection, H-2Kd/Dd antigens are expressed by satellite and Schwann cells but not neurons, suggesting additional posttranscriptional regulation of class I synthesis in neurons. Alternatively, the class I RNAs induced in neurons may not be derived from classical class I genes. Factors regulating H-2 class I expression emanate from within infected ganglia, probably from infected neurons themselves. However, induction of class I molecules was not maintained during latency, when viral gene expression in neurons is restricted to a single region within the virus repeats. These data have implications for the long-term survival of cells in HSV-infected neural tissue. PMID:8064236

  20. The AT-hook DNA binding ability of the Epstein Barr virus EBNA1 protein is necessary for the maintenance of viral genomes in latently infected cells.

    PubMed

    Chakravorty, Adityarup; Sugden, Bill

    2015-10-01

    Epstein Barr Virus (EBV) is a human tumor virus that is causally linked to malignancies such as Burkitt׳s lymphoma, and gastric and nasopharyngeal carcinomas. Tethering of EBV genomes to cellular chromosomes is required for the synthesis and persistence of viral plasmids in tumor cells. However, it is not established how EBV genomes are tethered to cellular chromosomes. We test the hypothesis that the viral protein EBNA1 tethers EBV genomes to chromosomes specifically through its N-terminal AT-hook DNA-binding domains by using a small molecule, netropsin, that has been shown to inhibit the AT-hook DNA-binding of EBNA1 in vitro. We show that netropsin forces the loss of EBV genomes from epithelial and lymphoid cells in an AT-hook dependent manner and that EBV-positive lymphoma cells are significantly more inhibited in their growth by netropsin than are corresponding EBV-negative cells.

  1. Recent developments in the search for a cure for HIV-1 infection: targeting the latent reservoir for HIV-1.

    PubMed

    Siliciano, Janet D; Siliciano, Robert F

    2014-07-01

    HIV-1 infection can now be readily controlled with combination antiretroviral therapy. However, the virus persists indefinitely in a stable latent reservoir in resting CD4(+) T cells. This reservoir generally prevents cure of the infection with combination antiretroviral therapy alone. However, several recent cases of potential HIV-1 cure have generated renewed optimism. Here we review these cases and consider new developments in our understanding of the latent reservoir. In addition, we consider clinical aspects of curative strategies to provide a more realistic picture of what a generally applicable cure for HIV-1 infection is likely to entail. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  2. In vivo activation of latent HIV with a synthetic bryostatin analog effects both latent cell "kick" and "kill" in strategy for virus eradication.

    PubMed

    Marsden, Matthew D; Loy, Brian A; Wu, Xiaomeng; Ramirez, Christina M; Schrier, Adam J; Murray, Danielle; Shimizu, Akira; Ryckbosch, Steven M; Near, Katherine E; Chun, Tae-Wook; Wender, Paul A; Zack, Jerome A

    2017-09-01

    The ability of HIV to establish a long-lived latent infection within resting CD4+ T cells leads to persistence and episodic resupply of the virus in patients treated with antiretroviral therapy (ART), thereby preventing eradication of the disease. Protein kinase C (PKC) modulators such as bryostatin 1 can activate these latently infected cells, potentially leading to their elimination by virus-mediated cytopathic effects, the host's immune response and/or therapeutic strategies targeting cells actively expressing virus. While research in this area has focused heavily on naturally-occurring PKC modulators, their study has been hampered by their limited and variable availability, and equally significantly by sub-optimal activity and in vivo tolerability. Here we show that a designed, synthetically-accessible analog of bryostatin 1 is better-tolerated in vivo when compared with the naturally-occurring product and potently induces HIV expression from latency in humanized BLT mice, a proven and important model for studying HIV persistence and pathogenesis in vivo. Importantly, this induction of virus expression causes some of the newly HIV-expressing cells to die. Thus, designed, synthetically-accessible, tunable, and efficacious bryostatin analogs can mediate both a "kick" and "kill" response in latently-infected cells and exhibit improved tolerability, therefore showing unique promise as clinical adjuvants for HIV eradication.

  3. In vivo activation of latent HIV with a synthetic bryostatin analog effects both latent cell "kick" and "kill" in strategy for virus eradication

    PubMed Central

    Marsden, Matthew D.; Schrier, Adam J.; Murray, Danielle; Shimizu, Akira; Ryckbosch, Steven M.; Chun, Tae-Wook; Wender, Paul A.

    2017-01-01

    The ability of HIV to establish a long-lived latent infection within resting CD4+ T cells leads to persistence and episodic resupply of the virus in patients treated with antiretroviral therapy (ART), thereby preventing eradication of the disease. Protein kinase C (PKC) modulators such as bryostatin 1 can activate these latently infected cells, potentially leading to their elimination by virus-mediated cytopathic effects, the host’s immune response and/or therapeutic strategies targeting cells actively expressing virus. While research in this area has focused heavily on naturally-occurring PKC modulators, their study has been hampered by their limited and variable availability, and equally significantly by sub-optimal activity and in vivo tolerability. Here we show that a designed, synthetically-accessible analog of bryostatin 1 is better-tolerated in vivo when compared with the naturally-occurring product and potently induces HIV expression from latency in humanized BLT mice, a proven and important model for studying HIV persistence and pathogenesis in vivo. Importantly, this induction of virus expression causes some of the newly HIV-expressing cells to die. Thus, designed, synthetically-accessible, tunable, and efficacious bryostatin analogs can mediate both a “kick” and “kill” response in latently-infected cells and exhibit improved tolerability, therefore showing unique promise as clinical adjuvants for HIV eradication. PMID:28934369

  4. The product of ORF O located within the domain of herpes simplex virus 1 genome transcribed during latent infection binds to and inhibits in vitro binding of infected cell protein 4 to its cognate DNA site

    PubMed Central

    Randall, Glenn; Lagunoff, Michael; Roizman, Bernard

    1997-01-01

    The partially overlapping ORF P and ORF O are located within the domains of the herpes simplex virus 1 genome transcribed during latency. Earlier studies have shown that ORF P is repressed by infected cell protein 4 (ICP4), the major viral regulatory protein, binding to its cognate site at the transcription initiation site of ORF P. The ORF P protein binds to p32, a component of the ASF/SF2 alternate splicing factors; in cells infected with a recombinant virus in which ORF P was derepressed there was a significant decrease in the expression of products of key regulatory genes containing introns. We report that (i) the expression of ORF O is repressed during productive infection by the same mechanism as that determining the expression of ORF P; (ii) in cells infected at the nonpermissive temperature for ICP4, ORF O protein is made in significantly lower amounts than the ORF P protein; (iii) the results of insertion of a sequence encoding 20 amino acids between the putative initiator methionine codons of ORF O and ORF P suggest that ORF O initiates at the methionine codon of ORF P and that the synthesis of ORF O results from frameshift or editing of its RNA; and (iv) glutathione S-transferase–ORF O fusion protein bound specifically ICP4 and precluded its binding to its cognate site on DNA in vitro. These and earlier results indicate that ORF P and ORF O together have the capacity to reduce the synthesis or block the expression of regulatory proteins essential for viral replication in productive infection. PMID:9294219

  5. 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

  6. 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

    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; BenMohamed, Lbachir

    2015-07-01

    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 (gD(53-61), gD(70-78), and gD(278-286)) were linked with a promiscuous CD4(+) T-cell epitope (gD(287-317)) 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. 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 blinding

  7. The latent cytomegalovirus decreases telomere length by microcompetition

    PubMed Central

    Javaherian, Adrian

    2015-01-01

    Reduced telomere length has been associated with aging and age-related diseases. Latent infection with the Cytomegalovirus (CMV) induces telomere shortening in the infected cells. Latent CMV infection may cause reduced telomere length via GABP transcription factor deficiency, according to the Microcompetition Theory. Microcompetition and viral-induced transcription factor deficiency is important since most people harbor a latent viral infection.

  8. 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.

  9. A built-in co-carcinogenic effect due to viruses involved in latent or persistent infections.

    PubMed

    Hersoug, Lars-Georg; Arnau, José

    2007-01-01

    A new hypothesis for some cancers, which combines the chromosomal instability theories with a co-carcinogenic effect of viruses causing latent or persistent infection, is presented. The hypothesis incorporates the multi-step model of cancer and that pre-cancerous cells reach a state of chromosomal instability. Because of chromosomal instability, the genome of these cell lines will lead to changes from generation to generation and will face a remarkable selection pressure both from lost traits, apoptosis, and from the immune system. Viruses causing latent or persistent infections have evolved many different genes capable to evade the immune system. If these viruses are harboured in the genome of pre-cancerous cells they could provide them with "superpowers" and with genes that may assist the cells to elude the immune system. The theory explains why cancer predominantly is a disease of old age. Upon aging, the immune system becomes reduced including the ability to control and suppress the viruses that cause latent or persistent infections. The risk of cancer could thereby increase as the immune functions decrease. The theory provides new insights to the genesis of cancers.

  10. Murine cytomegalovirus: detection of latent infection by nucleic acid hybridization technique.

    PubMed Central

    Cheung, K S; Huang, E S; Lang, D J

    1980-01-01

    The technique of nucleic acid hybridization was used to detect the presence of murine cytomegalovirus (MCMV)-specific deoxyribonucleic acid (DNA) in cell cultures and salivary gland tissues. The presence of approximately 4.5 and 0.2 genome equivalents per cell of MCMV-specific DNA was identified in cultures of salivary (ISG2) and prostate gland (IP) cells, respectively. These cells, derived from animals with experimentally induced latent infections, were negative for virus-specific antigens by immunofluorescence and on electron microscopy revealed no visible evidence of the presence of herpesviruses. A cell line derived from the salivary gland of an uninoculated animal (NSG2) was also found to possess MCMV-specific DNA (0.2 genome equivalents per cell). For this reason, salivary gland tissues from uninoculated animals supplied as "specific pathogen-free" mice by three commercial sources were tested upon arrival for the presence of MCMC-specific DNA. MCMV-specific DNA was detectable in pooled salivary gland extracts from uninoculated animals derived from two commercial sources. All of these animals were seronegative and virus negative by conventional infectivity assays. PMID:6247281

  11. Comparative study of different latent infections of herpes simplex virus type I in a murine model.

    PubMed

    Huang, Wen; Zhao, Ping; Chen, Xiao; Li, Ping; Zhao, Gaonian; Xu, Mingming; Chen, Xiuying; Xie, Peng

    2014-01-01

    This study aims to compare the different latent infections of herpes simplex virus type I in a murine model. One hundred and twenty BALB/c mice were randomly assigned into either of three groups: intravenous inoculation group, ocular abrasion group, and intranasal inoculation group. Six weeks later, the trigeminal ganglia (TG) were removed to detect the expression of HSV-I antigen. HSV DNA in TG was also detected by polymerase chain reaction to confirm latent infection. The rate of HSV DNA in TG detected in the intravenous inoculation group was 18/22 and 22/26 in the ocular abrasion group, both of which were higher than the rate detected in the intranasal inoculation group (18/30). The expression of HSV antigen in TG in these three groups was all negative. Mortality rate in the intravenous inoculation group was 8/30, which was much higher than those of the two other groups. Intranasal virus dripping, cornea abrasion, and intravenous injection can detect latent HSV-I infection in a murine model. Compared to two other groups, the cornea abrasion group showed less severe signs, a quicker recovery rate in acute infection, and higher incidence rate of latent infection. Therefore, it is an ideal method in the presence of latent HSV-I infection.

  12. Latent toxoplasmosis is associated with neurocognitive impairment in young adults with and without chronic HIV infection.

    PubMed

    Ene, L; Marcotte, T D; Umlauf, A; Grancea, C; Temereanca, A; Bharti, A; Achim, C L; Letendre, S; Ruta, S M

    2016-10-15

    We evaluated the impact of latent toxoplasmosis (LT) on neurocognitive (NC) and neurobehavioural functioning in young adults with and without chronic HIV infection, using a standardised NC test battery, self-reported Beck Depression Inventory, Frontal System Behavior Scale, MINI-International Neuropsychiatric Interview and risk-assessment battery. 194 young adults (median age 24years, 48.2% males) with chronic HIV infection (HIV+) since childhood and 51 HIV seronegative (HIV-) participants were included. HIV+ individuals had good current immunological status (median CD4: 479 cells/μl) despite a low CD4 nadir (median: 93 cells/μl). LT (positive anti-Toxoplasma IgG antibodies) was present in one third of participants. The impairment rates in the HIV- with and without Toxo were not significantly different (p=0.17). However, we observed an increasing trend (p<0.001) in impairment rates with HIV and LT status: HIV-/LT- (6.1%); HIV-/LT+ (22%), HIV+/LT- (31%), HIV+/LT+ (49%). In a multivariable analysis using the entire study group there were main effects on cognition for HIV and also for LT. Within the HIV+ group LT was associated with worse performance globally (p=0.006), in memory (p=0.009), speed of information processing (p=0.01), verbal (p=0.02) and learning (p=0.02) domains. LT was not associated with depressive symptoms, frontal systems dysfunction or risk behaviors in any of the groups. HIV participants with lower Toxoplasma antibody concentration had worse NC performance, with higher GDS values (p=0.03) and worse learning (p=0.002), memory (p=0.006), speed of information processing (p=0.01) T scores. Latent Toxoplasmosis may contribute to NC impairment in young adults, including those with and without chronic HIV infection.

  13. Activation of HIV-1 from latent infection via synergy of RUNX1 inhibitor Ro5-3335 and SAHA.

    PubMed

    Klase, Zachary; Yedavalli, Venkat S R K; Houzet, Laurent; Perkins, Molly; Maldarelli, Frank; Brenchley, Jason; Strebel, Klaus; Liu, Paul; Jeang, Kuan-Teh

    2014-03-01

    A major barrier to the elimination of HIV-1 infection is the presence of a pool of long-lived, latently infected CD4+ memory T-cells. The search for treatments to re-activate latent HIV to aid in clearance is hindered by the incomplete understanding of the mechanisms that lead to transcriptional silencing of viral gene expression in host cells. Here we identify a previously unknown role for RUNX1 in HIV-1 transcriptional latency. The RUNX proteins, in combination with the co-factor CBF-β, are critical transcriptional regulators in T-cells. RUNX1 strongly modulates CD4 expression and contributes to CD4+ T-cell function. We show that RUNX1 can bind DNA sequences within the HIV-1 LTR and that this binding represses transcription. Using patient samples we show a negative correlation between RUNX1 expression and viral load. Furthermore, we find that pharmacologic inhibition of RUNX1 by a small molecule inhibitor, Ro5-3335, synergizes with the histone deacetylase (HDAC) inhibitor SAHA (Vorinostat) to enhance the activation of latent HIV-1 in both cell lines and PBMCs from patients. Our findings indicate that RUNX1 and CBF-β cooperate in cells to modulate HIV-1 replication, identifying for the first time RUNX1 as a cellular factor involved in HIV-1 latency. This work highlights the therapeutic potential of inhibitors of RUNX1 to re-activate virus and aid in clearance of HIV-1.

  14. New approaches in the diagnosis and treatment of latent tuberculosis infection

    PubMed Central

    2010-01-01

    With nearly 9 million new active disease cases and 2 million deaths occurring worldwide every year, tuberculosis continues to remain a major public health problem. Exposure to Mycobacterium tuberculosis leads to active disease in only ~10% people. An effective immune response in remaining individuals stops M. tuberculosis multiplication. However, the pathogen is completely eradicated in ~10% people while others only succeed in containment of infection as some bacilli escape killing and remain in non-replicating (dormant) state (latent tuberculosis infection) in old lesions. The dormant bacilli can resuscitate and cause active disease if a disruption of immune response occurs. Nearly one-third of world population is latently infected with M. tuberculosis and 5%-10% of infected individuals will develop active disease during their life time. However, the risk of developing active disease is greatly increased (5%-15% every year and ~50% over lifetime) by human immunodeficiency virus-coinfection. While active transmission is a significant contributor of active disease cases in high tuberculosis burden countries, most active disease cases in low tuberculosis incidence countries arise from this pool of latently infected individuals. A positive tuberculin skin test or a more recent and specific interferon-gamma release assay in a person without overt signs of active disease indicates latent tuberculosis infection. Two commercial interferon-gamma release assays, QFT-G-IT and T-SPOT.TB have been developed. The standard treatment for latent tuberculosis infection is daily therapy with isoniazid for nine months. Other options include therapy with rifampicin for 4 months or isoniazid + rifampicin for 3 months or rifampicin + pyrazinamide for 2 months or isoniazid + rifapentine for 3 months. Identification of latently infected individuals and their treatment has lowered tuberculosis incidence in rich, advanced countries. Similar approaches also hold great promise for other

  15. [Efficacy of the treatment for latent tuberculosis infection and delayed reactivation of tuberculosis].

    PubMed

    Toyota, Makoto

    2013-09-01

    To evaluate the efficacy of treatment for latent tuberculosis infection and delayed reactivation of tuberculosis. During a large tuberculosis outbreak, 129 individuals who were in close contact with tuberculosis patients and subsequently tested strongly positive by the tuberculin skin test were followed up for 10 years after identification of the source case. Of the 129 individuals, 105 received treatment for latent tuberculosis infection for 6 months as per recommendation, while the remaining 24 did not receive treatment, because most of them were above 30 years of age and were therefore discouraged from receiving treatment, as was done in the earlier times in Japan. Of the 105 individuals, 5 (4.8%) were newly diagnosed with tuberculosis, and the average duration from identification of the source case to reactivation of tuberculosis was 53 months. Of the 24 individuals who did not receive treatment for latent tuberculosis infection, 6 (25.0%) were newly diagnosed with tuberculosis, and the average duration from identification of the source case to reactivation of tuberculosis was 8.2 months. The risk of active tuberculosis was reduced by 81.0% with treatment for latent tuberculosis infection, compared with that without treatment. Delayed reactivation of tuberculosis was observed among patients treated with isoniazid for latent tuberculosis infection for 6 months.

  16. 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.

  17. 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

  18. 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.

  19. Transcriptional reactivation of murine cytomegalovirus ie gene expression by 5-aza-2'-deoxycytidine and trichostatin A in latently infected cells despite lack of methylation of the major immediate-early promoter.

    PubMed

    Hummel, Mary; Yan, Shixian; Li, Zhigao; Varghese, Thomas K; Abecassis, Michael

    2007-04-01

    We have used a spleen explant model to investigate mechanisms of murine cytomegalovirus latency and reactivation. Induction of immediate-early (ie) gene expression occurs in explants after approximately 9 days in culture and virus reactivation follows induction of ie gene expression with kinetics similar to that of productive infection in vitro. This occurs independently of TNF receptor signalling. Treatment with the DNA methylation inhibitor 5-aza-2'-deoxycytidine and the histone deacetylase inhibitor trichostatin A results in more rapid induction of ie gene expression and reactivation of virus. Despite these results, which suggest a role for DNA methylation in maintenance of viral latency, we find that the major immediate-early promoter/enhancer is not methylated in latently infected mice. Our results support the hypothesis that latency is maintained by epigenetic control of ie gene expression, and that induction of ie gene expression leads to reactivation of virus, but suggest that these are not controlled by DNA methylation.

  20. Not to wake a sleeping giant: new insights into host-pathogen interactions identify new targets for vaccination against latent Mycobacterium tuberculosis infection.

    PubMed

    Lin, May Young; Ottenhoff, Tom H M

    2008-05-01

    Mycobacterium tuberculosis is one of the worlds' most successful and sophisticated pathogens. It is estimated that over 2 billion people today harbour latent M. tuberculosis infection without any clinical symptoms. As most new cases of active tuberculosis (TB) arise from this (growing) number of latently infected individuals, urgent measures to control TB reactivation are required, including post-exposure/therapeutic vaccines. The current bacille Calmette-Guérin (BCG) vaccine and all new generation TB vaccines being developed and tested are essentially designed as prophylactic vaccines. Unfortunately, these vaccines are unlikely to be effective in individuals already latently infected with M. tuberculosis. Here, we argue that detailed analysis of M. tuberculosis genes that are switched on predominantly during latent stage infection may lead to the identification of new antigenic targets for anti-TB strategies. We will describe essential host-pathogen interactions in TB with particular emphasis on TB latency and persistent infection. Subsequently, we will focus on novel groups of late-stage specific genes, encoded amongst others by the M. tuberculosis dormancy (dosR) regulon, and summarise recent studies describing human T-cell recognition of these dormancy antigens in relation to (latent) M. tuberculosis infection. We will discuss the possible relevance of these new classes of antigens for vaccine development against TB.

  1. Detection of interleukin-2 in addition to interferon-gamma discriminates active tuberculosis patients, latently infected individuals, and controls.

    PubMed

    Biselli, R; Mariotti, S; Sargentini, V; Sauzullo, I; Lastilla, M; Mengoni, F; Vanini, V; Girardi, E; Goletti, D; D' Amelio, R; Nisini, R

    2010-08-01

    Effective control of tuberculosis (TB) includes discrimination of subjects with active TB from individuals with latent TB infection (LTBI). As distinct interferon (IFN)-gamma and interleukin (IL)-2 profiles of antigen-specific T-cells have been associated with different clinical stages and antigen loads in several viral and bacterial diseases, we analysed these cytokines in TB using a modified QuantiFERON-TB Gold In Tube test. Detection of IL-2 in addition to IFN-gamma distinguishes not only Mycobacterium tuberculosis-infected subjects from healthy controls, but also individuals with LTBI from active TB patients. This may help to improve diagnostic tests for TB.

  2. Can Taenia solium latent post-oncospheral stages be found in muscle tissue of cysticercosis-infected pigs (Sus scrofa)?

    PubMed

    Rodrìguez, Mary L; Rodriguez, Silvia; Gonzalez, Armando E; Verastegui, Manuela; Bernal, Teresa; Jimenez, Juan A; Garcia, Hector H

    2006-02-01

    The existence of latent Taenia solium post-oncospheral stages in the tissues of infected pigs has been postulated. To assess whether such structures exist and can be detected, we examined muscle samples from cysticercosis-infected and uninfected pigs. Pork samples were homogenized, centrifuged, and resuspended in saline solution. Round microscopic structures of approximately 10 microm with variable refringence were found in the pellets of all samples from both infected and uninfected pigs. These became homogeneously red after staining with Sudan IV and disappeared after ether extraction. The only difference between samples from infected and uninfected pigs was the presence of inflammatory cells and tissue necrosis debris in the former group. Taenia solium oncospheres were stained and observed for comparative purposes, before and after inoculation into pork. Control oncospheres were ellipsoidal, had nucleated basophile cells in their interior, and showed red aggregates on their surfaces when stained with 3% Sudan IV. While rounded microscopical structures similar to those previously reported were found, these differed morphologically from oncospheres, were of a lipid nature, and occurred in both infected and uninfected animals. No evidence supporting the presence of latent post-oncospheral stages of Taenia solium was generated in this series of experiments.

  3. An In-Depth Comparison of Latent HIV-1 Reactivation in Multiple Cell Model Systems and Resting CD4+ T Cells from Aviremic Patients

    PubMed Central

    Spina, Celsa A.; Anderson, Jenny; Archin, Nancie M.; Bosque, Alberto; Chan, Jonathan; Famiglietti, Marylinda; Greene, Warner C.; Kashuba, Angela; Lewin, Sharon R.; Margolis, David M.; Mau, Matthew; Ruelas, Debbie; Saleh, Suha; Shirakawa, Kotaro; Siliciano, Robert F.; Singhania, Akul; Soto, Paula C.; Terry, Valeri H.; Verdin, Eric; Woelk, Christopher; Wooden, Stacey; Xing, Sifei; Planelles, Vicente

    2013-01-01

    The possibility of HIV-1 eradication has been limited by the existence of latently infected cellular reservoirs. Studies to examine control of HIV latency and potential reactivation have been hindered by the small numbers of latently infected cells found in vivo. Major conceptual leaps have been facilitated by the use of latently infected T cell lines and primary cells. However, notable differences exist among cell model systems. Furthermore, screening efforts in specific cell models have identified drug candidates for “anti-latency” therapy, which often fail to reactivate HIV uniformly across different models. Therefore, the activity of a given drug candidate, demonstrated in a particular cellular model, cannot reliably predict its activity in other cell model systems or in infected patient cells, tested ex vivo. This situation represents a critical knowledge gap that adversely affects our ability to identify promising treatment compounds and hinders the advancement of drug testing into relevant animal models and clinical trials. To begin to understand the biological characteristics that are inherent to each HIV-1 latency model, we compared the response properties of five primary T cell models, four J-Lat cell models and those obtained with a viral outgrowth assay using patient-derived infected cells. A panel of thirteen stimuli that are known to reactivate HIV by defined mechanisms of action was selected and tested in parallel in all models. Our results indicate that no single in vitro cell model alone is able to capture accurately the ex vivo response characteristics of latently infected T cells from patients. Most cell models demonstrated that sensitivity to HIV reactivation was skewed toward or against specific drug classes. Protein kinase C agonists and PHA reactivated latent HIV uniformly across models, although drugs in most other classes did not. PMID:24385908

  4. 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…

  5. Sequence Analysis of Raspberry latent virus Suggests a New Genus of Dicot Infecting Reoviruses

    USDA-ARS?s Scientific Manuscript database

    Currently, there are three assigned genera of plant reoviruses: Phytoreovirus, Fijivirus and Oryzavirus. With only two exceptions, all plant reoviruses infect monocotyledonous plants. The recent characterization of Raspberry latent virus (RpLV) isolated from red raspberry plants in northern Washingt...

  6. 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…

  7. Latent tuberculosis infection: the final frontier of tuberculosis elimination in the USA.

    PubMed

    LoBue, Philip A; Mermin, Jonathan H

    2017-10-01

    Since 1989, the USA has been pursuing the goal of tuberculosis elimination. After substantial progress during the past two decades, the rate of tuberculosis cases in the USA each year has now levelled off and remains well above the elimination threshold. Both epidemiological data and modelling underline the necessity of addressing latent tuberculosis infection if further progress is to be made in eliminating the disease. In this Personal View we explore next steps towards elimination. Given the estimated prevalence of latent tuberculosis infection, compared with the limited testing and treatment that currently occur, a major new effort is required. This effort should consist of a surveillance system or registry to monitor progress, scale-up of targeted testing for latent tuberculosis infection in at-risk populations, scale-up of short-course treatment regimens, engagement of affected communities and medical providers who serve those communities, and increased public health staffing for implementation and oversight. Such an effort would benefit greatly from the development of new tools, such as tests that better indicate reactivation risk, and even shorter latent tuberculosis infection treatment regimens than currently exist. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Screening and treatment of latent tuberculosis infection among HIV-infected patients in resource-rich settings.

    PubMed

    Lin, Ada W C; Lau, Susanna K P; Woo, Patrick C Y

    2016-01-01

    Current international guidelines recommend screening and treatment of latent tuberculosis (TB) infection in HIV-infected patients in all settings. The main factors affecting the risk of TB in HIV-infected patients include the level of immunosuppression, coverage of antiretroviral therapy and local TB burden. In resource-rich settings where antiretroviral therapy is more accessible and HIV-infected patients are expected to be diagnosed at an earlier stage, local TB burden remains a key factor on their risk of TB. This article reviewed the epidemiology of latent TB infection among the adult HIV-infected patients, and the use and benefit of screening and treatment of latent TB infection in resource-rich settings in the past decade. While such practice should be continued in countries with medium or high TB burden, targeted screening and treatment only for HIV-infected patients with additional risk factors for TB might be a more practical option in resource-rich countries with low TB burden.

  9. Association of vitamin D deficiency, season of the year, and latent tuberculosis infection among household contacts.

    PubMed

    Balcells, María Elvira; García, Patricia; Tiznado, Camila; Villarroel, Luis; Scioscia, Natalia; Carvajal, Camila; Zegna-Ratá, Francesca; Hernández, Mariluz; Meza, Paulina; González, Luis F; Peña, Carlos; Naves, Rodrigo

    2017-01-01

    Vitamin D (VD) enhances the immune response against Mycobacterium tuberculosis in vitro, and VD deficiency has been described in patients with active tuberculosis (TB). However, the role of hypovitaminosis D in the pathogenesis of early TB infection acquisition is unclear. We aimed to evaluate the association of VD deficiency, season of the year, and latent TB infection in household contacts (HHC), given that this is a potentially modifiable condition often related to nutritional deficiencies and lack of sun exposure. We prospectively enrolled new pulmonary TB cases (n = 107) and their HHC (n = 144) over a 2-year period in Santiago, Chile. We compared plasma 25-hydroxycholecalciferol (25OHD) levels and examined the influence of season, ethnic background, living conditions, and country of origin. Over 77% of TB cases and 62.6% of HHC had VD deficiency (<20 ng/ml). Median 25OHD concentration was significantly lower in TB cases than in HHC (11.7 vs. 18.2 ng/ml, p<0.0001). Migrants HHC had lower 25OHD levels than non-migrants (14.6 vs. 19.0 ng/ml, p = 0.026), and a trend towards a higher burden of latent TB infection (52.9% vs. 35.2%, p = 0.066). Multivariate analysis found VD deficiency in HHC was strongly associated with being sampled in winter/spring (adOR 25.68, 95%CI 7.35-89.7), corresponding to the seasons with lowest solar radiation exposure. Spring enrollment-compared with other seasons-was the chief risk factor for latent TB infection in HHC (adOR 3.14, 95%CI 1.28-7.69). Hypovitaminosis D was highly prevalent in TB cases and also in HHC. A marked seasonality was found for both VD levels and latent TB in HHC, with winter being the season with lowest VD levels and spring the season with the highest risk of latent TB infection.

  10. 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

  11. Tuberculosis in prisoners and their contacts in Chile: estimating incidence and latent infection.

    PubMed

    Aguilera, X P; González, C; Nájera-De Ferrari, M; Hirmas, M; Delgado, I; Olea, A; Lezaeta, L; Montaña, A; González, P; Hormazábal, J-C; Fernández, J; García, C; Herrera, T

    2016-01-01

    Contact investigation of tuberculosis (TB) patients in Chilean prisons. 1) To estimate TB incidence and the prevalence of latent tuberculous infection (LTBI) among prisoners and their contacts; and 2) to determine factors associated with disease transmission. Cross-sectional study conducted in 46 prisons (51% of the total prison population) to assess the prevalence of and risk factors for LTBI among contacts of prisoners newly diagnosed with pulmonary TB. We used in vitro interferon-gamma release assays to establish LTBI and a questionnaire to address risk factors. During the 1-year follow-up, we studied 418 contacts of 33 active TB cases. We found high TB incidence (123.9 per 100,000 prisoners) and high LTBI prevalence (29.4%) among contacts. LTBI rates are significantly higher in prison inmates than in non-prisoners (33.2% vs. 15.6%). Male sex, illicit drugs, malnutrition, corticosteroid use, low educational level and sharing a cell with a case increase the risk of LTBI. Multivariate analyses showed that corticosteroid use, duration of incarceration and overcrowding are the most relevant determinants for LTBI among all contacts. Our results confirm that incarceration increases the risk of tuberculous infection and TB disease, and that it was associated not only with origin from vulnerable groups, but also with the prison environment. Reinforcing TB control is essential to prevent TB transmission in prisons.

  12. Effects of ocular surface strontium-90 beta radiotherapy in dogs latently infected with canine herpesvirus-1.

    PubMed

    Nicklin, Amanda M; McEntee, Margaret C; Ledbetter, Eric C

    2014-12-05

    Latent canine herpesvirus-1 (CHV-1) infections are common in domestic dogs, but stimuli causing viral reactivation and recrudescent disease are poorly understood. Immunosuppressive pharmaceuticals are currently the only experimentally established triggers for recurrent ocular CHV-1 infection in dogs; however, ocular CHV-1 shedding has been reported clinically following strontium-90 beta radiotherapy of the ocular surface and it has been speculated that radiotherapy can directly induce viral reactivation. Strontium-90 is used as a beta radiation source for the treatment of a variety of neoplastic and immune-mediated canine ocular surface diseases. In the present study, the effects of ocular surface strontium-90 beta radiotherapy in dogs latently infected with CHV-1 were evaluated. Ten mature dogs with experimentally induced latent CHV-1 infections were randomly divided into two groups: one group received a single fraction 50 Gy radiation dose in one application from a strontium-90 ophthalmic applicator and the second group received sham radiotherapy. Dogs were then monitored for 45 days for recurrent ocular CHV-1 infection using clinical and virological outcome measures. Clinical ophthalmic examinations, ocular sample CHV-1 PCR assays, and serum CHV-1 virus neutralizing antibody assays were performed at specified intervals. No abnormalities suggestive of recurrent CHV-1 ocular disease were observed on clinical examination in any dog during the study. Ocular viral shedding was not detected and CHV-1 virus neutralizing titers remained stable in all dogs. A single fraction 50 Gy radiation dose administered to the ocular surface by strontium-90 beta radiotherapy did not result in detectable recurrent ocular CHV-1 infection in mature dogs with experimentally induced latent infection. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Use of whole genome sequencing to estimate the mutation rate of Mycobacterium tuberculosis during latent infection

    PubMed Central

    Ford, Christopher B.; Lin, Philana Ling; Chase, Michael; Shah, Rupal R.; Iartchouk, Oleg; Galagan, James; Mohaideen, Nilofar; Ioerger, Thomas R.; Sacchettini, James C.; Lipsitch, Marc; Flynn, JoAnne L.; Fortune, Sarah M.

    2011-01-01

    Mycobacterium tuberculosis (Mtb) has generated a global health catastrophe that has been compounded by the emergence of drug resistant Mtb strains. We used whole genome sequencing to compare the accumulation of mutations in Mtb isolated from cynomolgus macaques with active, latent and reactivated disease. Based on the distribution of SNPs observed, we calculated the mutation rates for these disease states. Our data suggest that Mtb acquires a similar number of chromosomal mutations during latency as occurs during active disease or in a logarithmically growing culture over the same period of time despite reduced bacterial replication during latent infection. The pattern of polymorphisms suggests that the mutational burden in vivo is due to oxidative DNA damage. Thus, we demonstrate that Mtb continues to acquire mutations during latency and provide a novel explanation for the observation that isoniazid monotherapy for latent tuberculosis is a risk factor for the emergence of INH resistance1,2. PMID:21516081

  14. Effects of Indomethacin on Acute, Subacute, and Latent Infections in Mice and Rats

    PubMed Central

    Robinson, Harry J.; Phares, Herbert F.; Graessle, Otto E.

    1968-01-01

    The comparative effect of indomethacin and hydrocortisone on the resistance of mice or rats to various acute, subacute, and latent bacterial infections was investigated. Large daily doses of indomethacin and hydrocortisone administered to mice challenged with bacterial pathogens, including Klebsiella pneumoniae AD, Salmonella schottmuelleri 3010, Staphylococcus aureus (Smith), Streptococcus pyogenes C203, Salmonella pullorum #2, Proteus vulgaris 1810, and Pseudomonas aeruginosa 2616, revealed that in essentially all of these acute infections, the mortality of the infected mice treated with indomethacin was essentially identical to that found in the infected controls. In contrast, hydrocortisone often lowered the resistance of mice to these acute infections. In a more chronic bacterial infection due to Corynebacterium kutscheri, hydrocortisone produced striking deleterious effects on resistance, whereas indomethacin administration in doses approaching the maximal tolerated level caused no observable adverse effects on host resistance. Indomethacin fed continuously to rats for 80 days, at maximal tolerated levels, caused no observable adverse effects on the host-parasite relationship of rats which were shown to harbor various latent infections. Hydrocortisone administration, however, lowered the resistance of rats as evidenced by increased mortality related directly to extensive bacterial infection. Insofar as infection is concerned, indomethacin behaved like other nonsteroid anti-inflammatory agents such as aspirin and phenylbutazone. PMID:5663575

  15. Defining nervous system susceptibility during acute and latent herpes simplex virus-1 infection.

    PubMed

    Menendez, Chandra M; Carr, Daniel J J

    2017-07-15

    Herpes simplex viruses are neurotropic human pathogens that infect and establish latency in peripheral sensory neurons of the host. Herpes Simplex Virus-1 (HSV-1) readily infects the facial mucosa that can result in the establishment of a latent infection in the sensory neurons of the trigeminal ganglia (TG). From latency, HSV-1 can reactivate and cause peripheral pathology following anterograde trafficking from sensory neurons. Under rare circumstances, HSV-1 can migrate into the central nervous system (CNS) and cause Herpes Simplex Encephalitis (HSE), a devastating disease of the CNS. It is unclear whether HSE is the result of viral reactivation within the TG, from direct primary infection of the olfactory mucosa, or from other infected CNS neurons. Areas of the brain that are susceptible to HSV-1 during acute infection are ill-defined. Furthermore, whether the CNS is a true reservoir of viral latency following clearance of virus during acute infection is unknown. In this context, this review will identify sites within the brain that are susceptible to acute infection and harbor latent virus. In addition, we will also address findings of HSV-1 lytic gene expression during latency and comment on the pathophysiological consequences HSV-1 infection may have on long-term neurologic performance in animal models and humans. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. [Consensus document on treatment of tuberculosis exposure and latent tuberculosis infection in children].

    PubMed

    2006-01-01

    The most important causes of the current tuberculosis pandemic are poverty, HIV infection, drug resistance, and the spread of infection by patients with latent tuberculosis infection. In industrialized countries, the main reasons for the increase of this disease are immigration from developing countries and the lack of effective surveillance programs. The situation of children is even more serious as they are more vulnerable to the disease than adults. The children most at risk are those who live with adults at risk for tuberculosis, immigrant children, and adoptees from developing countries. Although children are bacilliferous only exceptionally, the appropriate management of bacilliferous tuberculosis exposure and latent tuberculosis infection in children contributes to the creation of close surveillance of nuclear families and rigorous study of contacts. Moreover, it could prevent serious forms of the disease, which are more frequent in children. The principal objective of this second consensus document of the Spanish Society of Pediatric Infectious Diseases (Sociedad Española de Infectología Pediátrica [SEIP]) is to unify the criteria for the treatment of tuberculosis exposure and latent tuberculosis infection in children. A further aim is to increase awareness of the need for strict detection measures in high-risk populations among health authorities.

  17. Seroprevalence of latent Toxoplasma gondii infection among HIV-infected pregnant women in Bobo-Dioulasso, Burkina Faso.

    PubMed

    Bamba, S; Sourabié, Y; Guiguemdé, T R; Karou, D S; Simporé, J; Bambara, M; Villena, I

    2014-09-01

    The deficit of cellular immunity, as found in HIV infected individuals, may lead to the reactivation of latent Toxoplasma gondii cysts, with as consequence, the occurrence of toxoplasmosis and an eventual vertical transmission of the disease during pregnancy. The present study was designed for determining the occurrence of latent Toxoplasma gondii among HIV-infected pregnant women during the first trimester in Bobo-Dioulasso. Thus, 348 pregnant women aged from 17 to 47 years (average age of 6.64 ± 4.75 yaers) were enrolled. The specific anti-Toxoplasma gondii IgG and IgM antibodies were quantified from whole blood specimens using the high-sensitivity direct agglutination and the enzyme linked fluorescent assays, respectively, the IgG avidity test being used for the dating of the primary infection. The results revealed that the seroprevalence of Toxoplasma gondii latent infection was 34.7%. It was significantly higher in HIV-infected women compared with uninfected ones (68,7%; CI 95%: 43,6%-88,9%) versus (33,1%; CI 95%: 28, 2%-38,3%). In addition, all the occurrences of the high IgG avidity were closely linked with the presence of IgM. These results underlined the need for the clinical follow-up of the maternal HIV diseases including the toxoplasmosis during the pregnancy since; the newborns are still exposed to vertical transmission of Toxoplasma infection in endemic areas like Burkina Faso.

  18. A Novel In Vitro Human Granuloma Model of Sarcoidosis and Latent Tuberculosis Infection.

    PubMed

    Crouser, Elliott D; White, Peter; Caceres, Evelyn Guirado; Julian, Mark W; Papp, Audrey C; Locke, Landon W; Sadee, Wolfgang; Schlesinger, Larry S

    2017-10-01

    Many aspects of pathogenic granuloma formation are poorly understood, requiring new relevant laboratory models that represent the complexity (genetics and diversity) of human disease. To address this need, we developed an in vitro model of granuloma formation using human peripheral blood mononuclear cells (PBMCs) derived from patients with active sarcoidosis, latent tuberculosis (TB) infection (LTBI), or normal healthy control subjects. PBMCs were incubated for 7 days with uncoated polystyrene beads or beads coated with purified protein derivative (PPD) or human serum albumin. In response to PPD-coated beads, PBMCs from donors with sarcoidosis and LTBI formed robust multicellular aggregates resembling granulomas, displaying a typical T-helper cell type 1 immune response, as assessed by cytokine analyses. In contrast, minimal PBMC aggregation occurred when control PBMCs were incubated with PPD-coated beads, whereas the response to uncoated beads was negligible in all groups. Sarcoidosis PBMCs responded to human serum albumin-coated beads with modest cellular aggregation and inflammatory cytokine release. Whereas the granuloma-like aggregates formed in response to PPD-coated beads were similar for sarcoidosis and LTBI, molecular profiles differed significantly. mRNA expression patterns revealed distinct pathways engaged in early granuloma formation in sarcoidosis and LTBI, and they resemble molecular patterns reported in diseased human tissues. This novel in vitro human granuloma model is proposed as a tool to investigate mechanisms of early granuloma formation and for preclinical drug discovery research of human granulomatous disorders. Clinical trial registered with www.clinicaltrials.gov (NCT01857401).

  19. Incidence of persistent viraemia and latent feline leukaemia virus infection in cats with lymphoma.

    PubMed

    Stützer, Bianca; Simon, Karin; Lutz, Hans; Majzoub, Monir; Hermanns, Walter; Hirschberger, Johannes; Sauter-Louis, Carola; Hartmann, Katrin

    2011-02-01

    In the past, feline leukaemia virus (FeLV) infection, and also latent FeLV infection, were commonly associated with lymphoma and leukaemia. In this study, the prevalence of FeLV provirus in tumour tissue and bone marrow in FeLV antigen-negative cats with these tumours was assessed. Seventy-seven diseased cats were surveyed (61 antigen-negative, 16 antigen-positive). Blood, bone marrow, and tumour samples were investigated by two polymerase chain reaction (PCR) assays detecting deoxyribonucleic acid (DNA) sequences of the long terminal repeats (LTR) and the envelope (env) region of the FeLV genome. Immunohistochemistry (IHC) was performed in bone marrow and tumour tissue. None of the antigen-negative cats with lymphoma was detectably infected with latent FeLV. The prevalence of FeLV viraemia in cats with lymphoma was 20.8%. This suggests that causes other than FeLV play a role in tumorigenesis, and that latent FeLV infection is unlikely to be responsible for most feline lymphomas and leukaemias. Copyright © 2010. Published by Elsevier Ltd.

  20. New, previously unreported correlations between latent Toxoplasma gondii infection and excessive ethanol consumption.

    PubMed

    Samojłowicz, Dorota; Borowska-Solonynko, Aleksandra; Kruczyk, Marcin

    2017-09-18

    A number of world literature reports indicate that a latent Toxoplasma gondii infection leads to development of central nervous system disorders, which in turn may lead to altered behavior in the affected individuals. T. gondii infection has been observed to play the greatest role in drivers, suicides, and psychiatric patients. Studies conducted for this manuscript involve a different, never before really reported correlation between latent T. gondii infection and ethanol abuse. A total of 538 decedents with a known cause of death were included in the study. These individuals were divided into three groups: the risky behavior group, inconclusively risky behavior group, and control group. The criterion for this division was the likely effect of the individual's behavior on the mechanism and cause of his/her death. The material used for analyses were blood samples collected during routine medico-legal examinations in these cases. The blood samples were used to measure anti-T. gondii IgG antibodies with an enzyme-linked immunosorbent assay (ELISA). Moreover, the following data were recorded for each decedent: sex, age, circumstances of death, cause of death, time from death to autopsy, and (if provided) substance abuse status (alcohol, illicit drugs). In those cases where blood alcohol level or toxicology tests were requested by the Prosecutor's Office, their results were also included in our analysis. Test results demonstrated a strong correlation between latent T. gondii infection and engaging in risky behaviors leading to death. Moreover, analyses demonstrated a positive correlation between the presence of anti-T. gondii IgG antibodies and psychoactive substance (especially ethanol) abuse, however, the causal relationship remains unclear. Due to the fact that alcohol abuse constitutes a significant social problem, searching for eliminable risk factors for addiction is extremely important. Our analyses provided new important information on the possible effects of

  1. 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 Central

    Sawtell, Nancy M.; Thompson, Richard L.

    2016-01-01

    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

  2. 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.

  3. [Latent tuberculosis infection in healthcare personnel at a primary level general hospital in Catalonia, Spain].

    PubMed

    Sol Vidiella, Josep; Catalán Gómez, Teresa; Callau Casanova, Cristina; Lejeune, Marylène

    2014-01-01

    The aim was to analyze the prevalence of latent tuberculosis infection and associated risk factors in healthcare personnel at the Hospital de Tortosa Verge de la Cinta (Tarragona, Spain). This was a cross-sectional study of 398 workers at this hospital who underwent tuberculin skin testing for latent tuberculosis infection (LTBI) between 2001 and 2012.We also analyzed the relationship between LTBI and age, sex, job and work area according to their risk of exposure to tuberculosis(high, low, uncertain). The total prevalence of LTBI in our sample was 11.1% (95%CI 8.3%-14.5%). LBTI was associated with age and work area. Multivariate analysis showed that the risk of LTBI increased by 6.4% per 1 year increase in age. The prevalence of LTBI in this population approximates that of the general population in Spain.

  4. 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.

  5. Selective peptide inhibitors of antiapoptotic cellular and viral Bcl-2 proteins lead to cytochrome c release during latent Kaposi's sarcoma-associated herpesvirus infection.

    PubMed

    Burrer, Christine M; Foight, Glenna W; Keating, Amy E; Chan, Gary C

    2016-01-04

    Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with B-cell lymphomas including primary effusion lymphoma and multicentric Castleman's disease. KSHV establishes latency within B cells by modulating or mimicking the antiapoptotic Bcl-2 family of proteins to promote cell survival. Our previous BH3 profiling analysis, a functional assay that assesses the contribution of Bcl-2 proteins towards cellular survival, identified two Bcl-2 proteins, cellular Mcl-1 and viral KsBcl-2, as potential regulators of mitochondria polarization within a latently infected B-cell line, Bcbl-1. In this study, we used two novel peptide inhibitors identified in a peptide library screen that selectively bind KsBcl-2 (KL6-7_Y4eK) or KsBcl-2 and Mcl-1 (MS1) in order to decipher the relative contribution of Mcl-1 and KsBcl-2 in maintaining mitochondrial membrane potential. We found treatment with KL6-7_Y4eK and MS1 stimulated a similar amount of cytochrome c release from mitochondria isolated from Bcbl-1 cells, indicating that inhibition of KsBcl-2 alone is sufficient for mitochondrial outer membrane permiabilzation (MOMP) and thus apoptosis during a latent B cell infection. In turn, this study also identified and provides a proof-of-concept for the further development of novel KsBcl-2 inhibitors for the treatment of KSHV-associated B-cell lymphomas via the targeting of latently infected B cells.

  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. Sexual Behavior Latent Classes Among Men Who Have Sex With Men: Associations With Sexually Transmitted Infections.

    PubMed

    Rice, Cara E; Turner, Abigail Norris; Lanza, Stephanie T

    2016-08-12

    Men who have sex with men (MSM) are at disproportionate risk of acquisition of sexually transmitted infections (STIs). We used latent class analysis (LCA) to examine patterns of sexual behavior among MSM and how those patterns are related to STIs. We examined patterns of sexual behavior using behavioral and clinical data from a cross-sectional study of 235 MSM who presented to an urban sexual health clinic for STI testing. Analyzed data were collected using a combination of interviewer- and self-administered surveys and electronic health records. We used LCA to identify underlying subgroups of men based on their sexual behavior, described the demographics of the latent classes, and examined the association between the latent classes and STI status. We identified three latent classes of sexual behavior: Unprotected Anal Intercourse (UAI) Only (67%), Partner Seekers (14%), and Multiple Behaviors (19%). Men in the Multiple Behaviors class had a 67% probability of being STI positive, followed by men in the UAI Only class (27%) and men in the Partner Seekers class (22%). Examining the intersection of a variety of sexual practices indicates particular subgroups of MSM have the highest probability of being STI positive.

  8. Bryostatin-1 for latent virus reactivation in HIV-infected patients on antiretroviral therapy.

    PubMed

    Gutiérrez, Carolina; Serrano-Villar, Sergio; Madrid-Elena, Nadia; Pérez-Elías, Maria J; Martín, Maria Elena; Barbas, Coral; Ruipérez, Javier; Muñoz, Eduardo; Muñoz-Fernández, Maria Angeles; Castor, Trevor; Moreno, Santiago

    2016-06-01

    The protein kinase C (PKC) agonist bryostatin-1 has shown significant ex-vivo potency to revert HIV-1 latency, compared with other latency reversing agents (LRA). The safety of this candidate LRA remains to be proven in treated HIV-1-infected patients. In this pilot, double-blind phase I clinical-trial (NCT 02269605), we included aviraemic HIV-1-infected patients on triple antiretroviral therapy to evaluate the effects of two different single doses of bryostatin-1 (10 or 20 μg/m) compared with placebo. Twelve patients were included, four in each arm. Bryostatin-1 was well tolerated in all participants. Two patients in the 20 μg/m arm developed grade 1 headache and myalgia. No detectable increases of cell-associated unspliced (CA-US) HIV-1-RNA were observed in any study arm, nor differences in HIV-1 mRNA dynamics between arms (P = 0.44). The frequency of samples with low-level viraemia did not differ between arms and low-level viraemia did not correlate with CA-US HIV-1-RNA levels (P = 0.676). No changes were detected on protein kinase C (PKC) activity and in biomarkers of inflammation (sCD14 and interleukin-6) in any study arm. After the single dose of bryostatin-1, plasma concentrations were under detection limits in all the patients in the 10 μg/m arm, and below 50 pg/ml (0.05 nmol/l) in those in the 20 μg/m arm. Bryostatin-1 was safe at the single doses administered. However, the drug did not show any effect on PKC activity or on the transcription of latent HIV, probably due to low plasma concentrations. This study will inform next trials aimed at assessing higher doses, multiple dosing schedules or combination studies with synergistic drugs.

  9. Association of vitamin D deficiency, season of the year, and latent tuberculosis infection among household contacts

    PubMed Central

    García, Patricia; Tiznado, Camila; Villarroel, Luis; Scioscia, Natalia; Carvajal, Camila; Zegna-Ratá, Francesca; Hernández, Mariluz; Meza, Paulina; González, Luis F.; Peña, Carlos; Naves, Rodrigo

    2017-01-01

    Objectives Vitamin D (VD) enhances the immune response against Mycobacterium tuberculosis in vitro, and VD deficiency has been described in patients with active tuberculosis (TB). However, the role of hypovitaminosis D in the pathogenesis of early TB infection acquisition is unclear. We aimed to evaluate the association of VD deficiency, season of the year, and latent TB infection in household contacts (HHC), given that this is a potentially modifiable condition often related to nutritional deficiencies and lack of sun exposure. Methods We prospectively enrolled new pulmonary TB cases (n = 107) and their HHC (n = 144) over a 2-year period in Santiago, Chile. We compared plasma 25-hydroxycholecalciferol (25OHD) levels and examined the influence of season, ethnic background, living conditions, and country of origin. Results Over 77% of TB cases and 62.6% of HHC had VD deficiency (<20 ng/ml). Median 25OHD concentration was significantly lower in TB cases than in HHC (11.7 vs. 18.2 ng/ml, p<0.0001). Migrants HHC had lower 25OHD levels than non-migrants (14.6 vs. 19.0 ng/ml, p = 0.026), and a trend towards a higher burden of latent TB infection (52.9% vs. 35.2%, p = 0.066). Multivariate analysis found VD deficiency in HHC was strongly associated with being sampled in winter/spring (adOR 25.68, 95%CI 7.35–89.7), corresponding to the seasons with lowest solar radiation exposure. Spring enrollment–compared with other seasons–was the chief risk factor for latent TB infection in HHC (adOR 3.14, 95%CI 1.28–7.69). Conclusions Hypovitaminosis D was highly prevalent in TB cases and also in HHC. A marked seasonality was found for both VD levels and latent TB in HHC, with winter being the season with lowest VD levels and spring the season with the highest risk of latent TB infection. PMID:28403225

  10. Murid Herpesvirus-4 Exploits Dendritic Cells to Infect B Cells

    PubMed Central

    Frederico, Bruno; Gill, Michael B.; Smith, Christopher M.; Belz, Gabrielle T.; Stevenson, Philip G.

    2011-01-01

    Dendritic cells (DCs) play a central role in initiating immune responses. Some persistent viruses infect DCs and can disrupt their functions in vitro. However, these viruses remain strongly immunogenic in vivo. Thus what role DC infection plays in the pathogenesis of persistent infections is unclear. Here we show that a persistent, B cell-tropic gamma-herpesvirus, Murid Herpesvirus-4 (MuHV-4), infects DCs early after host entry, before it establishes a substantial infection of B cells. DC-specific virus marking by cre-lox recombination revealed that a significant fraction of the virus latent in B cells had passed through a DC, and a virus attenuated for replication in DCs was impaired in B cell colonization. In vitro MuHV-4 dramatically altered the DC cytoskeleton, suggesting that it manipulates DC migration and shape in order to spread. MuHV-4 therefore uses DCs to colonize B cells. PMID:22102809

  11. 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

  12. 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.

  13. IFN-γ/TNF-α ratio in response to immuno proteomically identified human T-cell antigens of Mycobacterium tuberculosis - The most suitable surrogate biomarker for latent TB infection.

    PubMed

    Prabhavathi, Maddineni; Pathakumari, Balaji; Raja, Alamelu

    2015-08-01

    The enormous reservoir of latent TB infection (LTBI) poses a major hurdle for global TB control. The existing Tuberculin skin test (TST) and IFN-γ release assays (IGRAs) are found to be suboptimal for LTBI diagnosis. Previously we had taken an immunoproteomic approach and identified 10 protein fractions (contains 16 proteins), which are solely recognized by LTBI. In a cohort of 40 pulmonary TB patients (PTB) and 35 healthy household contacts (HHC), IFN-γ and TNF-α response were measured against 16 antigens by using 1:10 diluted whole blood assay. Among all the antigens, IFN-γ response to Rv2626c has shown positivity of 88.57% in HHC and 7.5% in PTB group. IFN-γ response to combination of Rv2626c + Rv3716c has demonstrated 100% positivity in HHC and 17.5% positivity in PTB respectively. Compared to individual cytokines (i.e. IFN-γ and TNF-α), ratio of IFN-γ/TNF-α has shown promising results for diagnosis of LTBI. IFN-γ/TNF-α ratio against Rv3716c and TrxC has exhibited a positivity of 94.29% in HHC and 5% in PTB group. Accession of Rv2626c and Rv3716c may improve the diagnostic performance of existing QFT-GIT. Independent of QFT-GIT assay, ratio of IFN-γ/TNF-α in response to either Rv3716c or TrxC may acts as suitable surrogate biomarker for LTBI.

  14. The Global Burden of Latent Tuberculosis Infection: A Re-estimation Using Mathematical Modelling

    PubMed Central

    Houben, Rein M. G. J.

    2016-01-01

    Background The existing estimate of the global burden of latent TB infection (LTBI) as “one-third” of the world population is nearly 20 y old. Given the importance of controlling LTBI as part of the End TB Strategy for eliminating TB by 2050, changes in demography and scientific understanding, and progress in TB control, it is important to re-assess the global burden of LTBI. Methods and Findings We constructed trends in annual risk in infection (ARI) for countries between 1934 and 2014 using a combination of direct estimates of ARI from LTBI surveys (131 surveys from 1950 to 2011) and indirect estimates of ARI calculated from World Health Organisation (WHO) estimates of smear positive TB prevalence from 1990 to 2014. Gaussian process regression was used to generate ARIs for country-years without data and to represent uncertainty. Estimated ARI time-series were applied to the demography in each country to calculate the number and proportions of individuals infected, recently infected (infected within 2 y), and recently infected with isoniazid (INH)-resistant strains. Resulting estimates were aggregated by WHO region. We estimated the contribution of existing infections to TB incidence in 2035 and 2050. In 2014, the global burden of LTBI was 23.0% (95% uncertainty interval [UI]: 20.4%–26.4%), amounting to approximately 1.7 billion people. WHO South-East Asia, Western-Pacific, and Africa regions had the highest prevalence and accounted for around 80% of those with LTBI. Prevalence of recent infection was 0.8% (95% UI: 0.7%–0.9%) of the global population, amounting to 55.5 (95% UI: 48.2–63.8) million individuals currently at high risk of TB disease, of which 10.9% (95% UI:10.2%–11.8%) was isoniazid-resistant. Current LTBI alone, assuming no additional infections from 2015 onwards, would be expected to generate TB incidences in the region of 16.5 per 100,000 per year in 2035 and 8.3 per 100,000 per year in 2050. Limitations included the quantity and

  15. Deregulated microRNAs in CD4+ T cells from individuals with latent tuberculosis versus active tuberculosis.

    PubMed

    Fu, Yurong; Yi, Zhengjun; Li, Jianhua; Li, Ruifang

    2014-03-01

    The mechanisms of latent tuberculosis (TB) infection remain elusive. Roles of microRNA (miRNA) have been highlighted in pathogen-host interactions recently. To identify miRNAs involved in the immune response to TB, expression profiles of miRNAs in CD4(+) T cells from patients with latent TB, active TB and healthy controls were investigated by microarray assay and validated by RT-qPCR. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were used to analyse the significant functions and involvement in signalling pathways of the differentially expressed miRNAs. To identify potential target genes for miR-29, interferon-γ (IFN-γ) mRNA expression was measured by RT-qPCR. Our results showed that 27 miRNAs were deregulated among the three groups. RT-qPCR results were generally consistent with the microarray data. We observed an inverse correlation between miR-29 level and IFN-γ mRNA expression in CD4(+) T cells. GO and KEGG pathway analysis showed that the possible target genes of deregulated miRNAs were significantly enriched in mitogen-activated protein kinase signalling pathway, focal adhesion and extracellular matrix receptor interaction, which might be involved in the transition from latent to active TB. In all, for the first time, our study revealed that some miRNAs in CD4(+) T cells were altered in latent and active TB. Function and pathway analysis highlighted the possible involvement of miRNA-deregulated mRNAs in TB. The study might help to improve understanding of the relationship between miRNAs in CD4(+) T cells and TB, and laid an important foundation for further identification of the underlying mechanisms of latent TB infection and its reactivation. © 2013 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  16. 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.

  17. Herpes simplex virus 1 microRNAs expressed abundantly during latent infection are not essential for latency in mouse trigeminal ganglia

    PubMed Central

    Kramer, Martha F.; Jurak, Igor; Pesola, Jean M.; Boissel, Sandrine; Knipe, David M.; Coen, Donald M.

    2013-01-01

    Several herpes simplex virus 1 microRNAs are encoded within or near the latency associated transcript (LAT) locus, and are expressed abundantly during latency. Some of these microRNAs can repress the expression of important viral proteins and are hypothesized to play important roles in establishing and/or maintaining latent infections. We found that in lytically infected cells and in acutely infected mouse ganglia, expression of LAT-encoded microRNAs was weak and unaffected by a deletion that includes the LAT promoter. In mouse ganglia latently infected with wild type virus, the microRNAs accumulated to high levels, but deletions of the LAT promoter markedly reduced expression of LAT-encoded microRNAs and also miR-H6, which is encoded upstream of LAT and can repress expression of ICP4. Because these LAT deletion mutants establish and maintain latent infections, these microRNAs are not essential for latency, at least in mouse trigeminal ganglia, but may help promote it. PMID:21782205

  18. Time-dependent infectivity and flexible latent and infectious periods in compartmental models of plant disease.

    PubMed

    Cunniffe, N J; Stutt, R O J H; van den Bosch, F; Gilligan, C A

    2012-04-01

    Compartmental models have become the dominant theoretical paradigm in mechanistic modeling of plant disease and offer well-known advantages in terms of analytic tractability, ease of simulation, and extensibility. However, underlying assumptions of constant rates of infection and of exponentially distributed latent and infectious periods are difficult to justify. Although alternative approaches, including van der Plank's seminal discrete time model and models based on the integro-differential formulation of Kermack and McKendrick's model, have been suggested for plant disease and relax these unrealistic assumptions, they are challenging to implement and to analyze. Here, we propose an extension to the susceptible, exposed, infected, and removed (SEIR) compartmental model, splitting the latent and infection compartments and thereby allowing time-varying infection rates and more realistic distributions of latent and infectious periods to be represented. Although the model is, in fact, more general, we specifically target plant disease by demonstrating how it can represent both the van der Plank model and the most commonly used variant of the Kermack and McKendrick (K & M) model (in which the infectivity response is delay Gamma distributed). We show how our reformulation retains the numeric and analytic tractability of SEIR models, and how it can be used to replicate earlier analyses of the van der Plank and K & M models. Our reformulation has the advantage of using elementary mathematical techniques, making implementation easier for the nonspecialist. We show a practical implication of these results for disease control. By taking advantage of the easy extensibility characteristic of compartmental models, we also investigate the effects of including additional biological realism. As an example, we show how the more realistic infection responses we consider interact with host demography and lead to divergent invasion thresholds when compared with the "standard" SEIR

  19. Donor-derived tuberculosis (TB): isoniazid-resistant TB transmitted from a lung transplant donor with inadequately treated latent infection.

    PubMed

    Jensen, T O; Darley, D R; Goeman, E E; Shaw, K; Marriott, D J; Glanville, A R

    2016-10-01

    Donor-derived tuberculosis (TB) is an increasingly recognized complication of solid organ transplantation. We report a case of isoniazid-resistant pulmonary TB in a lung transplant recipient. The patient acquired the infection from the lung donor who was previously empirically treated with isoniazid for latent TB. The case highlights the caveat that, while adequate treatment of latent TB with isoniazid is presumed, meticulous screening of donors is required.

  20. Infection of brain-derived cells with the human immunodeficiency virus.

    PubMed Central

    Chiodi, F; Fuerstenberg, S; Gidlund, M; Asjö, B; Fenyö, E M

    1987-01-01

    A malignant glioma cell line was infected with the human T-lymphotropic virus type IIIB isolate of the human immunodeficiency virus. Infection appeared to be latent rather than productive. Through contact with monocytic or lymphoid cells, the virus present in the glioma cells could be transmitted and gave rise to a fully productive infection. Images PMID:3644020

  1. Use of Video Directly Observed Therapy for Treatment of Latent Tuberculosis Infection - Johnson County, Kansas, 2015.

    PubMed

    Holzschuh, Elizabeth Lawlor; Province, Stacie; Johnson, Krystle; Walls, Caitlin; Shemwell, Cathy; Martin, Gary; Showalter, Amy; Dunlay, Jennifer; Conyers, Andrew; Griffin, Phil; Tausz, Nancy

    2017-04-14

    Tuberculosis (TB) is caused by the bacterium Mycobacterium tuberculosis and is spread from person to person through the air. TB can be spread in congregate settings, such as school environments, to varying degrees, based on factors including duration of contact and air ventilation (1); therefore, evaluating potential contacts and exposures can be challenging. In February 2015, a student at a Kansas high school received a diagnosis of active pulmonary TB disease. Screening of 385 (91%) school contacts, four (100%) household contacts, and 19 (90%) social contacts resulted in the identification of 50 persons with latent TB infection. Johnson County Department of Health and Environment (JCDHE) Public Health Emergency Preparedness personnel used their experience with points of distribution logistics to optimize testing clinic layouts and implement the incident command structure. Open communication with students, school staff members, the public, and the media about the investigation from the outset was imperative to reduce rumors and unease that can accompany a large communicable disease investigation. The large number of persons needing treatment for latent TB overwhelmed JCDHE's two TB nurses. As a result, JCDHE developed a policy and procedure to allow persons who met eligibility requirements to complete 12 weekly doses of isoniazid and rifapentine treatment using video directly observed therapy (VDOT) rather than traditional in-person directly observed therapy (DOT). This procedure facilitated treatment compliance and completion; among the eligible 15 persons who chose the 12-week VDOT option, 14 (93%) completed treatment. State and local health departments might consider use of VDOT to monitor treatment of persons with latent TB infection.

  2. Antibody response of HIV-infected patients to latent, cerebral and recently acquired toxoplasmosis.

    PubMed

    Machala, L; Malý, M; Hrdá, S; Rozsypal, H; Stanková, M; Kodym, P

    2009-02-01

    The aim of this longitudinal study with 626 HIV-infected patients was to evaluate the capability of serological tests in diagnosing the presence of Toxoplasma gondii infection in HIV-infected patients, as well as the potential impact of various treatment regimes on serological results. Low IgG antibody levels and stable or declining titres predominated. IgM positivity occurred in ten patients (one seroconversion, seven latent, two cerebral toxoplasmosis). Complement fixation test (CFT) titres >or=1:32 imply that the relative risk of cerebral toxoplasmosis is 6.84 (95% confidence interval [CI] 1.44-32.5) but with a predictive value of only 14.0% (95% CI 5.3-27.9). Values of specific antibodies are not biassed by antiretroviral treatment and/or prophylaxis for toxoplasmosis, and the detection of specific antibodies is very useful in the identification of T. gondii infection in the HIV-infected population, but the role of serology in predicting the clinical manifestation of T. gondii infection is limited.

  3. The interrelation between intestinal parasites and latent TB infections among newly resettled refugees in Texas.

    PubMed

    Board, Amy R; Suzuki, Sumihiro

    2016-01-01

    Previous research has documented that parasite infection may increase vulnerability to TB among certain at risk populations. The purpose of this study was to identify whether an association exists between latent tuberculosis infection (LTBI) and intestinal parasite infection among newly resettled refugees in Texas while controlling for additional effects of region of origin, age and sex. Data for all refugees screened for both TB and intestinal parasites between January 2010 and mid-October 2013 were obtained from the Texas Refugee Health Screening Program and were analyzed using logistic regression. A total of 9860 refugees were included. In multivariable logistic regression analysis, pathogenic and non-pathogenic intestinal parasite infections yielded statistically significant reduced odds of LTBI. However, when individual parasite species were analyzed, hookworm infection indicated statistically significant increased odds of LTBI (OR 1.674, CI: 1.126-2.488). A positive association exists between hookworm infection and LTBI in newly arrived refugees to Texas. More research is needed to assess the nature and extent of these associations. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Characterization of Neuronal Populations in the Human Trigeminal Ganglion and Their Association with Latent Herpes Simplex Virus-1 Infection

    PubMed Central

    Horn, Anja K. E.; Sinicina, Inga; Strupp, Michael; Brandt, Thomas; Theil, Diethilde; Hüfner, Katharina

    2013-01-01

    Following primary infection Herpes simplex virus-1 (HSV-1) establishes lifelong latency in the neurons of human sensory ganglia. Upon reactivation HSV-1 can cause neurological diseases such as facial palsy, vestibular neuritis or encephalitis. Certain populations of sensory neurons have been shown to be more susceptible to latent infection in the animal model, but this has not been addressed in human tissue. In the present study, trigeminal ganglion (TG) neurons expressing six neuronal marker proteins were characterized, based on staining with antibodies against the GDNF family ligand receptor Ret, the high-affinity nerve growth factor receptor TrkA, neuronal nitric oxide synthase (nNOS), the antibody RT97 against 200kDa neurofilament, calcitonin gene-related peptide and peripherin. The frequencies of marker-positive neurons and their average neuronal sizes were assessed, with TrkA-positive (61.82%) neurons being the most abundant, and Ret-positive (26.93%) the least prevalent. Neurons positive with the antibody RT97 (1253 µm2) were the largest, and those stained against peripherin (884 µm2) were the smallest. Dual immunofluorescence revealed at least a 4.5% overlap for every tested marker combination, with overlap for the combinations TrkA/Ret, TrkA/RT97 and Ret/nNOS lower, and the overlap between Ret/CGRP being higher than would be expected by chance. With respect to latent HSV-1 infection, latency associated transcripts (LAT) were detected using in situ hybridization (ISH) in neurons expressing each of the marker proteins. In contrast to the mouse model, co-localization with neuronal markers Ret or CGRP mirrored the magnitude of these neuron populations, whereas for the other four neuronal markers fewer marker-positive cells were also LAT-ISH+. Ret and CGRP are both known to label neurons related to pain signaling. PMID:24367603

  5. 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.

  6. Potential Economic Viability of Two Proposed Rifapentine-Based Regimens for Treatment of Latent Tuberculosis Infection

    PubMed Central

    Holland, David P.; Sanders, Gillian D.; Hamilton, Carol D.; Stout, Jason E.

    2011-01-01

    Rationale Rifapentine-based regimens for treating latent tuberculosis infection (LTBI) are being considered for future clinical trials, but even if they prove effective, high drug costs may limit their economic viability. Objectives To inform clinical trial design by estimating the potential costs and effectiveness of rifapentine-based regimens for treatment of latent tuberculosis infection (LTBI). Methods We used a Markov model to estimate cost and societal benefits for three regimens for treating LTBI: Isoniazid/rifapentine daily for one month, isoniazid/rifapentine weekly for three months (self-administered and directly-observed), and isoniazid daily for nine months; a strategy of “no treatment” used for comparison. Costs, quality-adjusted life-years gained, and instances of active tuberculosis averted were calculated for all arms. Results Both daily isoniazid/rifapentine for one month and weekly isoniazid/rifapentine for three months were less expensive and more effective than other strategies under a wide variety of clinically plausibly parameter estimates. Daily isoniazid/rifapentine for one month was the least expensive and most effective regimen. Conclusions Daily isoniazid/rifapentine for one month and weekly isoniazid/rifapentine for three months should be studied in a large-scale clinical trial for efficacy. Because both regimens performed well even if their efficacy is somewhat reduced, study designers should consider relaxing non-inferiority boundaries. PMID:21789248

  7. Supervised preventive therapy for latent tuberculosis infection in illegal immigrants in Italy.

    PubMed

    Matteelli, A; Casalini, C; Raviglione, M C; El-Hamad, I; Scolari, C; Bombana, E; Bugiani, M; Caputo, M; Scarcella, C; Carosi, G

    2000-11-01

    In a multicenter, prospective, randomized, open-label study of isoniazid-preventive therapy (IPT) for latent tuberculosis infection, illegal immigrants from countries where tuberculosis is highly endemic were enrolled at two clinical sites in Northern Italy. Of 208 eligible subjects, 82 received supervised IPT at a dose of 900 mg twice weekly for 6 mo (Regimen A), 73 received unsupervised IPT 900 mg twice weekly for 6 mo (Regimen B), and 53 received unsupervised IPT 300 mg daily for 6 mo (Regimen C). Supervised IPT was delivered at either one tuberculosis clinic or one migrant clinic. The probability of completing a 26-wk regimen was 7, 26, and 41% in Regimens A, B, and C, respectively (p < 0.005, Log- rank test calculated using Kaplan-Meier plots). The mean time to dropout was 3. 8, 6, and 6.2 wk in Regimens A, B, and C, respectively (p = 0.003 for regimen A versus either Regimens B or C). Treatment was stopped in five subjects (2.4%) because of adverse events. The rate of completion of preventive therapy for latent tuberculosis infection among illegal immigrants was low. Supervised, clinic-based administration of IPT significantly reduced adherence. Alternative strategies to implement preventive therapy in illegal immigrants are clearly required.

  8. 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.

  9. Latent tuberculosis among persons at risk for infection with HIV, Tijuana, Mexico.

    PubMed

    Garfein, Richard S; Laniado-Laborin, Rafael; Rodwell, Timothy C; Lozada, Remedios; Deiss, Robert; Burgos, Jose Luis; Cuevas-Mota, Jazmine; Cerecer, Paris; Moser, Kathleen; Volker, Maria Luisa; Strathdee, Steffanie A

    2010-05-01

    Because there is little routine tuberculosis (TB) screening in Mexico, the prevalence of latent TB infection (LTBI) is unknown. In the context of an increasing HIV epidemic in Tijuana, Mexico, understanding prevalence of LTBI to anticipate emergence of increased LTBI reactivation is critical. Therefore, we recruited injection drug users, noninjection drug users, female sex workers, and homeless persons for a study involving risk assessment, rapid HIV testing, and TB screening. Of 503 participants, the overall prevalences of TB infection, HIV infection, and TB/HIV co-infection were 57%, 4.2%, and 2.2%, respectively; no significant differences by risk group (p>0.05) were observed. Two participants had TB (prevalence 398/100,000). Incarceration in Mexico (odds ratio [OR] 2.28), age (OR 1.03 per year), and years lived in Tijuana (OR 1.02 per year) were independently associated with TB infection (p<0.05). Frequent LTBI in marginalized persons may lead to increases in TB as HIV spreads.

  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. © The Author(s) 2015.

  11. Nicotine applied by transdermal patch induced HSV-1 reactivation and ocular shedding in latently infected rabbits.

    PubMed

    Myles, M E; Alack, C; Manino, P M; Reish, E R; Higaki, S; Maruyama, K; Mallakin, A; Azcuy, A; Barker, S; Ragan, F A; Thompson, H; Hill, James M

    2003-04-01

    The identification of factors involved in herpes virus latency and reactivation is critical to a better understanding of the mechanisms essential to viral neuroinvasiveness and neurovirulence. Recurrent episodes of ocular herpes infections cause irreversible corneal scarring and are the primary cause of loss of vision due to an infectious agent in industrialized countries. In this study, we examined the ability of nicotine, a compound known to be involved in stress-associated immunomodulation and recognized as one of the most frequently used addictive agents, to induce ocular shedding in rabbits latently infected with herpes simplex virus type 1 (HSV-1) strain McKrae. New Zealand white rabbits latently infected with HSV-1 at 3-4 weeks post-inoculation were randomly divided into two groups. The corneas of all rabbits were free of lesions as verified by slit lamp biomicroscopy. One group received nicotine by transdermal patch (21 mg/day) for 20 days and the other group served as the control. Reactivation data were obtained by detection of virus in tear film collected by ocular swabbing performed concurrently with the administration of nicotine. Compilation of data from three separate experiments demonstrated that 16.5% (258/1560) of the swabs taken from rabbits treated with nicotine were positive for virus, compared with 8.3% (53/639) of swabs taken from controls. Rabbits receiving nicotine exhibited a significantly (P < 0.0001) higher rate of ocular shedding than controls. The concentration of nicotine in the serum was determined at various times (0-24 hrs) after new patch replacement. Peak (average) serum level of nicotine was obtained 8 hours after patch replacement and exhibited a broad range of values (0.233 microg/mL-6.21 microg/mL). These results suggest that an initial systemic exposure to nicotine significantly increases HSV-1 reactivation. Further studies are needed to reveal any effects of nicotine dependency and nicotine withdrawal on herpesvirus

  12. Bovine Herpes Virus 1 (BHV-1) and Herpes Simplex Virus Type 1 (HSV-1) Promote Survival of Latently Infected Sensory Neurons, in Part by Inhibiting Apoptosis

    PubMed Central

    Jones, Clinton

    2013-01-01

    α-Herpesvirinae subfamily members, including herpes simplex virus type 1 (HSV-1) and bovine herpes virus 1 (BHV-1), initiate infection in mucosal surfaces. BHV-1 and HSV-1 enter sensory neurons by cell-cell spread where a burst of viral gene expression occurs. When compared to non-neuronal cells, viral gene expression is quickly extinguished in sensory neurons resulting in neuronal survival and latency. The HSV-1 latency associated transcript (LAT), which is abundantly expressed in latently infected neurons, inhibits apoptosis, viral transcription, and productive infection, and directly or indirectly enhances reactivation from latency in small animal models. Three anti-apoptosis genes can be substituted for LAT, which will restore wild type levels of reactivation from latency to a LAT null mutant virus. Two small non-coding RNAs encoded by LAT possess anti-apoptosis functions in transfected cells. The BHV-1 latency related RNA (LR-RNA), like LAT, is abundantly expressed during latency. The LR-RNA encodes a protein (ORF2) and two microRNAs that are expressed in certain latently infected neurons. Wild-type expression of LR gene products is required for stress-induced reactivation from latency in cattle. ORF2 has anti-apoptosis functions and interacts with certain cellular transcription factors that stimulate viral transcription and productive infection. ORF2 is predicted to promote survival of infected neurons by inhibiting apoptosis and sequestering cellular transcription factors which stimulate productive infection. In addition, the LR encoded microRNAs inhibit viral transcription and apoptosis. In summary, the ability of BHV-1 and HSV-1 to interfere with apoptosis and productive infection in sensory neurons is crucial for the life-long latency-reactivation cycle in their respective hosts. PMID:25278776

  13. Bovine Herpes Virus 1 (BHV-1) and Herpes Simplex Virus Type 1 (HSV-1) Promote Survival of Latently Infected Sensory Neurons, in Part by Inhibiting Apoptosis.

    PubMed

    Jones, Clinton

    2013-01-01

    α-Herpesvirinae subfamily members, including herpes simplex virus type 1 (HSV-1) and bovine herpes virus 1 (BHV-1), initiate infection in mucosal surfaces. BHV-1 and HSV-1 enter sensory neurons by cell-cell spread where a burst of viral gene expression occurs. When compared to non-neuronal cells, viral gene expression is quickly extinguished in sensory neurons resulting in neuronal survival and latency. The HSV-1 latency associated transcript (LAT), which is abundantly expressed in latently infected neurons, inhibits apoptosis, viral transcription, and productive infection, and directly or indirectly enhances reactivation from latency in small animal models. Three anti-apoptosis genes can be substituted for LAT, which will restore wild type levels of reactivation from latency to a LAT null mutant virus. Two small non-coding RNAs encoded by LAT possess anti-apoptosis functions in transfected cells. The BHV-1 latency related RNA (LR-RNA), like LAT, is abundantly expressed during latency. The LR-RNA encodes a protein (ORF2) and two microRNAs that are expressed in certain latently infected neurons. Wild-type expression of LR gene products is required for stress-induced reactivation from latency in cattle. ORF2 has anti-apoptosis functions and interacts with certain cellular transcription factors that stimulate viral transcription and productive infection. ORF2 is predicted to promote survival of infected neurons by inhibiting apoptosis and sequestering cellular transcription factors which stimulate productive infection. In addition, the LR encoded microRNAs inhibit viral transcription and apoptosis. In summary, the ability of BHV-1 and HSV-1 to interfere with apoptosis and productive infection in sensory neurons is crucial for the life-long latency-reactivation cycle in their respective hosts.

  14. 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

  15. Isoniazid vs. Rifampin for Latent Tuberculosis Infection in Jail Inmates: Toxicity and Adherence

    PubMed Central

    White, Mary C.; Tulsky, Jacqueline P.; Lee, Ju Ruey-Jiuan; Chen, Lisa; Goldenson, Joe; Spetz, Joanne; Kawamura, L. Masae

    2012-01-01

    This open-label randomized trial compared isoniazid (9 months) to rifampin (4 months) on toxicity and completion in a jailed population with latent tuberculosis infection. Rifampin resulted in fewer elevated liver function tests (risk ratio [RR] 0.39, 95% confidence interval [CI] [0.18, 0.86]) and less toxicity requiring medication withdrawal (RR 0.51, 95% CI [0.13, 2.01]), although one participant receiving rifampin experienced an allergic reaction. Completion was achieved for 33% receiving rifampin compared to 26% receiving isoniazid (p = .10). With careful monitoring rifampin is a safe and less toxic regimen and appears to be a reasonable alternative because of its shorter duration, allowing more people to complete treatment behind bars. Therapy completion in released inmates is unacceptably low and ensuring follow-up after discharge must be part of a decision to treat. PMID:22419641

  16. Latency-Associated Viral Interleukin-10 (IL-10) Encoded by Human Cytomegalovirus Modulates Cellular IL-10 and CCL8 Secretion during Latent Infection through Changes in the Cellular MicroRNA hsa-miR-92a

    PubMed Central

    Poole, Emma; Avdic, Selmir; Hodkinson, Jemima; Jackson, Sarah; Wills, Mark; Slobedman, Barry

    2014-01-01

    ABSTRACT The UL111A gene of human cytomegalovirus encodes a viral homologue of the cellular immunomodulatory cytokine interleukin 10 (cIL-10), which, due to alternative splicing, results in expression of two isoforms designated LAcmvIL-10 (expressed during both lytic and latent infection) and cmvIL-10 (identified only during lytic infection). We have analyzed the functions of LAcmvIL-10 during latent infection of primary myeloid progenitor cells and found that LAcmvIL-10 is responsible, at least in part, for the known increase in secretion of cellular IL-10 and CCL8 in the secretomes of latently infected cells. This latency-associated increase in CCL8 expression results from a concomitant LAcmvIL-10-mediated suppression of the expression of the cellular microRNA (miRNA) hsa-miR-92a, which targets CCL8 directly. Taking the data together, we show that the previously observed downregulation of hsa-miR-92a and upregulation of CCL8 during HCMV latent infection of myeloid cells are intimately linked via the latency-associated expression of LAcmvIL-10. IMPORTANCE HCMV latency causes significant morbidity and mortality in immunocompromised individuals, yet HCMV is carried silently (latently) in 50 to 90% of the population. Understanding how HCMV maintains infection for the lifetime of an infected individual is critical for the treatment of immunocompromised individuals suffering with disease as a result of HCMV. In this study, we analyze one of the proteins that are expressed during the “latent” phase of HCMV, LAcmvIL-10, and find that the expression of the gene modulates the microenvironment of the infected cell, leading to evasion of the immune system. PMID:25253336

  17. Latent tuberculosis infection in patients with chronic plaque psoriasis: evidence from the Italian Psocare Registry.

    PubMed

    Gisondi, P; Cazzaniga, S; Chimenti, S; Maccarone, M; Picardo, M; Girolomoni, G; Naldi, L

    2015-06-01

    The nationwide prevalence of latent tuberculosis infection (LTBI) in Italian patients with psoriasis has never been investigated. To estimate the nationwide prevalence of LTBI in Italian patients with psoriasis who are candidates for systemic treatment. Data were obtained from the Psocare Registry on those patients (n = 4946) with age > 18 years, systemic treatment at entry specified and tuberculin skin test (TST) performed according to the Mantoux method. LTBI diagnosis was based on a positive TST result in the absence of any clinical, radiological or microbiological evidence of active tuberculosis. Latent tuberculosis infection was diagnosed in 8·3% of patients with psoriasis (409 of 4946). The prevalence of LTBI was lower in patients on biologics than in those on conventional systemic treatments, ranging from 4·3% (19 of 444) of patients on adalimumab to 31% (eight of 26) of those on psoralen-ultraviolet A (P < 0·05). Independent factors associated with LTBI were male sex [odds ratio (OR) 1·30, 95% confidence interval (CI) 1·04-1·62; P = 0·02], age over 55 years (OR 2·93, 95% CI 2·18-3·93; P < 0·001) and being entered into a conventional treatment (OR 3·83, 95% CI 3·10-4·74; P < 0·001). Positive history of tuberculosis was seen in 1% of patients (n = 49). The nationwide prevalence of LTBI in Italian patients with psoriasis candidate to systemic treatment is high, and screening is recommended prior to biological treatment. © 2014 British Association of Dermatologists.

  18. QuantiFERON-TB Gold test for screening latent tuberculosis infection in hemodialysis patients.

    PubMed

    Sayarlioğlu, Hayriye; Gül, Mustafa; Eren Dağli, Canan; Doğan, Ekrem; Sahin, Murat; Uçar, Mehmet Ali; Köksal, Nurhan; Sayarlioğlu, Mehmet; Tahta, Mümtaz Kerim

    2011-01-01

    Hemodialysis patients are at increased risk of latent tuberculosis infection (LTBI) compared with the general population. QuantiFERON-TB Gold (QFT-G) for LTBI detection is more promising than tuberculin skin test (TST) in hemodialysis patients. The aim of this study is to determine whether the QFT-G is more sensitive than the TST in hemodialysis patients in LTBI. Eighty nine hemodialysis patients were evaluated for latent tuberculosis infection with the TST and QFT-G. Blood was obtained for QFT-G, and then TST was administered to all patients. Demographic information, laboratory tests, chest radiography results and BCG vaccination status were collected on standardized patient medical files. Forty patients had positive QFT-G results. 56 patients had TST induration above 5 mm, 28 patients above 10 mm. 61 patients had BCG vaccination scar. Statistically significant correlation was detected between TST and QFT-G (p< 0.05). In the BCG non-vaccinated subgroup, TST was positive in 8 (29%) patients and the QFT-G was positive in 11 (39%). Among the 21 non vaccinated patients with results for both tests, the concordance between the TST and QFT-G was 82%, k= 0.61, p= 0.001. We found good agreement between the TST and QFT-G test for LTBI in non vaccinated hemodialysis patients, whereas we found poor agreement in vaccinated patients. Because BCG vaccination is widely used in our country, the QFT-G test might be more useful for the diagnosis of LTBI than TST in hemodialysis patients who are suspected to have LTBI.

  19. [Screening contacts for latent tuberculosis infection (LTBI) using an interferon test in Paris in 2009].

    PubMed

    Fournier, A; Antoun, F; Collignon, A; Muller, G; Rouvier, J; Ayache, B; Guesnon, M-S; Larnaudie, S

    2012-01-01

    There are two reasons for screening contacts: one is to identify cases of secondary tuberculosis disease (TB) and the other is to identify new cases of latent tuberculosis infection (LTBI). The tuberculin skin test (TST) and the interferon-gamma-release assay (IGRA) have their limitations when used for the detection of LTBI. They neither allow a definite diagnosis of LTBI nor provide information as to the date of onset. The present study was observational, multi-centre (four centers) and retrospective. Six hundred and one contacts were included. The results of the QFT test showed 88 positive (15 %). Among the 144 index cases, all presented with pulmonary disease and 89 cases were sputum positive. In our series, 101 contacts belonged to the family circle. The four factors that had a significant positive impact on the result of the QFT test were: increasing age, the region of birth of the contact (high incidence areas), both of which may indicate old infection, while contact within the family and sputum positivity of the index case probably indicate recent infection. Only sputum positivity influenced the decision to treat the LTBI. We propose a tool aimed at facilitating the decision making process in QFT positive cases. Estimation of the duration of LTBI should help the physician to decide on the need for preventative treatment as well as a search for factors that increase the risk of progression to TB disease.

  20. Analysis of latent tuberculosis and mycobacterium avium infection data using mixture models

    PubMed Central

    Villate, José I; Ibáñez, Berta; Cabriada, Valentín; Pijoán, José I; Taboada, Jorge; Urkaregi, Arantza

    2006-01-01

    Background Estimation of the frequency of latent tuberculosis infection (LTBI) is difficult in areas with low tuberculosis infection rates and high exposure to non-tuberculous mycobacteria (NTM), including BCG vaccination. The objective was to assess LTBI and M avium infection and to estimate their probability based on skin tests responses in an infant population from a region with the aforementioned characteristics. Methods A population-based tuberculin skin test (TST) and sensitin (M avium) survey was conducted on seven years old infants in Biscay, a province from The Basque Country (Spain). 2268 schoolchildren received sensitin and 5277 TST. Participation rate was 89%. Commonly used estimation methods were compared with a method based on the fit of mixture models using the Expectation Maximization algorithm. Functions estimating the probabilities of LTBI and M avium infection given the observed skin tests responses were developed for vaccinated and unvaccinated children. Results LTBI prevalences varied widely according to the estimation method. The mixture model provided prevalences higher than expected although intermediates between those obtained by currently recommended approaches. Exposure to previous BCG vaccine produces an upward shift of an average of about 3 mm on the induration size to attain the same probability of infection. Conclusion Our results confirm the commonplace exposure to NTM which effect should be taken into account when performing and assessing tuberculin surveys. The use of mixture analysis under the empirical Bayes framework allows to better estimate the probability of LTBI in settings with presence of other NTM and high BCG-vaccination coverage. An estimation of the average effect of BCG vaccination on TST induration is also provided. These models maximise information coming from classical tuberculin surveys and could be used together with the newly developed blood tests to improve survey's specificity and cost-effectiveness. PMID

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

    PubMed

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

    2013-12-01

    There are currently no routine screening procedures for active tuberculosis (TB) or latent tuberculous infection (LTBI) in Malaysian prisons. 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. 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. 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. LTBI is highly prevalent, associated with previous incarceration, and suggests the need for routine TB screening on entry to Malaysian prisons.

  2. The multifactorial aetiology of fracture nonunion and the importance of searching for latent infection

    PubMed Central

    Tsang, J.; Hopper, G.; Keenan, G.; Simpson, A. H. R. W.

    2016-01-01

    and the importance of searching for latent infection. Bone Joint Res 2016;5:512–519. DOI: 10.1302/2046-3758.510.BJR-2016-0138. PMID:27784669

  3. Infection Cycle of Artichoke Italian Latent Virus in Tobacco Plants: Meristem Invasion and Recovery from Disease Symptoms

    PubMed Central

    Santovito, Elisa; Mascia, Tiziana; Siddiqui, Shahid A.; Minutillo, Serena Anna; Valkonen, Jari P. T.; Gallitelli, Donato

    2014-01-01

    Nepoviral infections induce recovery in fully expanded leaves but persist in shoot apical meristem (SAM) by a largely unknown mechanism. The dynamics of infection of a grapevine isolate of Artichoke Italian latent virus (AILV-V, genus Nepovirus) in tobacco plants, including colonization of SAM, symptom induction and subsequent recovery of mature leaves from symptoms, were characterized. AILV-V moved from the inoculated leaves systemically and invaded SAM in 7 days post-inoculation (dpi), remaining detectable in SAM at least up to 40 dpi. The new top leaves recovered from viral symptoms earliest at 21 dpi. Accumulation of viral RNA to a threshold level was required to trigger the overexpression of RDR6 and DCL4. Consequently, accumulation of viral RNA decreased in the systemically infected leaves, reaching the lowest concentration in the 3rd and 4th leaves at 23 dpi, which was concomitant with recovery of the younger, upper leaves from disease symptoms. No evidence of virus replication was found in the recovered leaves, but they contained infectious virus particles and were protected against re-inoculation with AILV-V. In this study we also showed that AILV-V did not suppress initiation or maintenance of RNA silencing in transgenic plants, but was able to interfere with the cell-to-cell movement of the RNA silencing signal. Our results suggest that AILV-V entrance in SAM and activation of RNA silencing may be distinct processes since the latter is triggered in fully expanded leaves by the accumulation of viral RNA above a threshold level rather than by virus entrance in SAM. PMID:24911029

  4. Characterization of Prunus-infecting apricot latent virus-like Foveaviruses: evolutionary and taxonomic implications.

    PubMed

    Youssef, Fater; Marais, Armelle; Faure, Chantal; Barone, Maria; Gentit, Pascal; Candresse, Thierry

    2011-02-01

    The complete genomic sequences of four Prunus-infecting Apricot latent virus (ApLV) like isolates were determined and used to analyze the taxonomic position and variability of these viruses. The results indicate that all isolates show a typical Foveavirus genetic organization. Despite an average 23% nucleotide divergence, they show strong colinearity with only three regions of significant indel variability, in the internal and 3' non-coding regions and variable N-terminal half of the coat protein (CP). Sequence comparisons using the polymerase (Pol) and CP genes provide a conflicting taxonomic picture, with divergence level in the Pol and CP genes suggesting the existence of a single or of two species, respectively. However, a range of considerations argue that all four isolates should likely be considered as belonging to the ApLV species. ApLV is closely related to Apple stem pitting virus and could be considered a sister species to it, with ASPV being specialized to infect members of the Maloideae family and ApLV members of the Prunoideae. Analysis of selection pressures affecting the five open reading frames of ApLV and ASPV identified two regions under strong purifying selection, that coding for the conserved C-terminal half of the CP and the gene coding for the first protein of the triple gene block (TGBp1).

  5. Screening for latent tuberculosis infection among undocumented immigrants in Swiss healthcare centres; a descriptive exploratory study.

    PubMed

    Bodenmann, Patrick; Vaucher, Paul; Wolff, Hans; Favrat, Bernard; de Tribolet, Fanny; Masserey, Eric; Zellweger, Jean-Pierre

    2009-03-24

    Migration is one of the major causes of tuberculosis in developed countries. Undocumented patients are usually not screened at the border and are not covered by a health insurance increasing their risk of developing the disease unnoticed. Urban health centres could help identify this population at risk. The objective of this study is to assess the prevalence of latent tuberculosis infection (LTBI) and adherence to preventive treatment in a population of undocumented immigrant patients. All consecutive undocumented patients that visited two urban healthcare centres for vulnerable populations in Lausanne, Switzerland for the first time were offered tuberculosis screening with an interferon-gamma assay. Preventive treatment was offered if indicated. Adherence to treatment was evaluated monthly over a nine month period. Of the 161 participants, 131 (81.4%) agreed to screening and 125 had complete examinations. Twenty-four of the 125 patients (19.2%; CI95% 12.7;27.2) had positive interferon-gamma assay results, two of which had active tuberculosis. Only five patients with LTBI completed full preventive treatments. Five others initiated the treatment but did not follow through. Screening for tuberculosis infection in this hard-to-reach population is feasible in dedicated urban clinics, and the prevalence of LTBI is high in this vulnerable population. However, the low adherence to treatment is an important public health concern, and new strategies are needed to address this problem.

  6. 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

  7. 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. Copyright ©ERS 2015.

  8. Characterization of virus-induced gene silencing in tobacco plants infected with apple latent spherical virus.

    PubMed

    Yaegashi, H; Yamatsuta, T; Takahashi, T; Li, C; Isogai, M; Kobori, T; Ohki, S; Yoshikawa, N

    2007-01-01

    Apple latent spherical virus (ALSV) expressing green fluorescent protein (GFP-ALSV) was used for analysis of virus-induced gene silencing (VIGS) in tobacco plants expressing GFP (GFP-tobacco). In GFP-tobacco inoculated with GFP-ALSV, small dark spots appeared on inoculated leaves at 5 days post-inoculation (dpi), then expanded, and finally covered the whole area of the leaves after 12 dpi. Most of the fluorescence of upper leaves above the 12th true leaf disappeared at 21 dpi. Thus, GFP-ALSV infection efficiently triggered VIGS of a transgene (GFP gene) in tobacco plants. Analysis of GFP-silenced leaves showed that viral RNAs and proteins accumulated in all leaves where most GFP mRNA had been degraded. The siRNAs derived from ALSV-RNAs were not detected in samples from which siRNA of GFP mRNA could be easily detected. Direct tissue blot analysis showed that the spread of GFP-ALSV always preceded the induction of VIGS in infected leaves of GFP-tobacco. GFP leaf patch tests using Nicotiana benthamiana line 16c showed that Vp20, one of the three capsid proteins, is a silencing suppressor which interferes with systemic silencing.

  9. Prevalence of latent tuberculosis infection among tuberculosis laboratory workers in Iran.

    PubMed

    Nasehi, Mahshid; Hashemi-Shahraki, Abdolrazagh; Doosti-Irani, Amin; Sharafi, Saeed; Mostafavi, Ehsan

    2017-01-01

    The risk of transmission of Mycobacterium tuberculosis from patients to health care workers (HCWs) is a neglected problem in many countries, including Iran. The aim of this study was to estimate the prevalence of latent tuberculosis (TB) infection (LTBI) among TB laboratory staff in Iran, and to elucidate the risk factors associated with LTBI. All TB laboratory staff (689 individuals) employed in the TB laboratories of 50 Iranian universities of medical sciences and a random sample consisting of 317 low-risk HCWs were included in this cross-sectional study. Participants with tuberculin skin test indurations of 10 mm or more were considered to have an LTBI. The prevalence of LTBI among TB laboratory staff and low-risk HCWs was 24.83% (95% confidence interval [CI], 21.31 to 27.74%) and 14.82% (95% CI, 11.31 to 19.20%), respectively. No active TB cases were found in either group. After adjusting for potential confounders, TB laboratory staff were more likely to have an LTBI than low-risk HCWs (prevalence odds ratio, 2.06; 95% CI, 1.35 to 3.17). This study showed that LTBI are an occupational health problem among TB laboratory staff in Iran. This study reinforces the need to design and implement simple, effective, and affordable TB infection control programs in TB laboratories in Iran.

  10. Prevalence of latent tuberculosis infection among tuberculosis laboratory workers in Iran

    PubMed Central

    2017-01-01

    OBJECTIVES The risk of transmission of Mycobacterium tuberculosis from patients to health care workers (HCWs) is a neglected problem in many countries, including Iran. The aim of this study was to estimate the prevalence of latent tuberculosis (TB) infection (LTBI) among TB laboratory staff in Iran, and to elucidate the risk factors associated with LTBI. METHODS All TB laboratory staff (689 individuals) employed in the TB laboratories of 50 Iranian universities of medical sciences and a random sample consisting of 317 low-risk HCWs were included in this cross-sectional study. Participants with tuberculin skin test indurations of 10 mm or more were considered to have an LTBI. RESULTS The prevalence of LTBI among TB laboratory staff and low-risk HCWs was 24.83% (95% confidence interval [CI], 21.31 to 27.74%) and 14.82% (95% CI, 11.31 to 19.20%), respectively. No active TB cases were found in either group. After adjusting for potential confounders, TB laboratory staff were more likely to have an LTBI than low-risk HCWs (prevalence odds ratio, 2.06; 95% CI, 1.35 to 3.17). CONCLUSIONS This study showed that LTBI are an occupational health problem among TB laboratory staff in Iran. This study reinforces the need to design and implement simple, effective, and affordable TB infection control programs in TB laboratories in Iran. PMID:28092930

  11. Latent tuberculosis infection in a migrant agricultural community in Baja California, Mexico.

    PubMed

    Garfein, Richard S; Burgos, Jose Luis; Rodriquez-Lainz, Alfonso; Brodine, Stephanie; Pietrucha, Amanda; Rondinelli, Amanda; Laniado-Laborin, Rafael; Ibarra, Elvira; Cañez, Alejandro; Fraga, Miguel

    2011-10-01

    The objectives were to estimate the prevalence and identify correlates of latent tuberculosis infection (LTBI) among residents of a migrant agricultural community in San Quintín, Baja-California, Mexico. Residents completed a questionnaire and had their blood tested for LTBI using the QuantiFERON(®)-TB Gold In-Tube (QFT) assay. Among 133 participants, 39.8% (95% CI 31.5-48.7%) tested QFT-positive. Having crossed the U.S.-Mexican border since living in San Quintin (P = 0.03), consuming unpasteurized milk (P = 0.02) and receiving health care at IMSS-Oportunidades in the last 6 months (P = 0.03) were independently associated with QFT-positivity. High LTBI prevalence in this community emphasizes the need for TB education and LTBI treatment for its residents. Association with travel to the U.S. suggests the potential for TB transmission across borders. Higher QFT-positivity among those consuming unpasteurized milk could indicate M. bovis infection, previously reported among Mexican migrants living in U.S. border cities.

  12. A model of latent adenovirus 5 infection in the guinea pig (Cavia porcellus).

    PubMed

    Vitalis, T Z; Keicho, N; Itabashi, S; Hayashi, S; Hogg, J C

    1996-03-01

    A model of adenovirus 5 (Ad5) infection was developed in guinea pigs to begin to study its role in the pathogenesis of peripheral lung inflammation. Forty animals were inoculated intranasally with 10(7.0) pfu of Ad5/animal, and 15 animals inoculated with sterile culture media served as controls. Viral titres were 10(4.4), 10(6.1), 10(5.2), and 10(2.9) pfu/animal, on days 1, 3, 4, and 7 after infection, respectively. In situ hybridization to viral DNA and immunocytochemistry for Ad5 E1A protein localized the virus to airway and alveolar epithelial cells. Histologic examination showed an extensive inflammatory cell infiltration around the airways, with epithelial necrosis and an alveolar exudate that caused localized alveolar collapse in the infected areas. Immunocytochemistry identified the cells in the infiltrate as cytotoxic T cells. Although all animals 20 and 47 days after infection had seroconverted to Ad5, virus was not detected in these groups either by viral plaque assay or in situ hybridization. Ad5 E1A DNA was detected by polymerase chain reaction in five of six animals 20 days after infection and in five of five animals 47 days after infection. In these same animals, E1A protein was detected 20 days after infection in two and 47 days after infection in one while persistent bronchiolitis was observed in four and three animals 20 and 47 days after infection, respectively. These results demonstrate that the guinea pig provides a useful model to study the role of Ad5 infection in chronic airway inflammation.

  13. 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

    2016-02-05

    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.

  14. Comparison of genotypes of Toxoplasma gondii in domestic cats from Australia with latent infection or clinical toxoplasmosis.

    PubMed

    Brennan, Anthea; Donahoe, Shannon L; Beatty, Julia A; Belov, Katherine; Lindsay, Scott; Briscoe, Katherine A; Šlapeta, Jan; Barrs, Vanessa R

    2016-09-15

    Whether Toxoplasma gondii genotype is associated with disease severity in naturally occurring toxoplasmosis in domestic cats is unknown. The aim of this study was to compare genotypes of T. gondii in latently infected cats with those in cats with clinical toxoplasmosis. Results of a PCR targeting the B1 gene to detect T. gondii DNA were positive in tissue samples from 11 of 17 (65%) seropositive cats tested including four with clinical toxoplasmosis and seven with latent infections, as determined by serology, histologic findings and immunohistochemistry. Three of the four cats with clinical toxoplasmosis were immunosuppressed. Complete genotyping was performed in seven cats using PCR-RFLP at 12 loci (SAG1, 5'SAG2 and 3'SAG2, altSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) and direct sequencing of the multi-copy B1 gene. Partial genotyping using six loci was performed in one cat with latent infection. T. gondii type II (ToxoDB genotype #3) was determined in four cats with clinical toxoplasmosis and three cats with latent toxoplasmosis Novel T. gondii B1 gene polymorphisms were detected in two strains (at nucleotide posititions 233, 366 and 595) and a B1 gene polymorphism unique to Australia was identified in another (guanine/adenine at nucleotide position 378). One cat was co-infected with two or more type-II like strains at 3'SAG2. The results of this study suggest that the infecting T. gondii genotype, based on these 12 loci, is not a determinant of clinical disease in cats naturally infected with T. gondii and type II strains are prevalent in Australia. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Epstein-Barr virus latent genes.

    PubMed

    Kang, Myung-Soo; Kieff, Elliott

    2015-01-23

    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.

  16. 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

  17. In-depth sequencing of the siRNAs associated with peach latent mosaic viroid infection

    PubMed Central

    2010-01-01

    Background It has been observed that following viroid infection, there is an accumulation of viroid-derived siRNAs in infected plants. Some experimental results suggest that these small RNAs may be produced by the plant defense system to protect it from infection, indicating that viroids can elicit the RNA-silencing pathways. The objective of this study is to identify in the peach latent mosaic viroid (PLMVd), a model RNA genome, the regions that are most susceptible to RNA interference machinery. Results The RNA isolated from an infected tree have been used to sequence in parallel viroid species and small non-coding RNA species. Specifically, PLMVd RNAs were amplified, cloned and sequenced according to a conventional approach, while small non-coding RNAs were determined by high-throughput sequencing. The first led to the typing of 18 novel PLMVd variants. The second provided a library of small RNAs including 880 000 sequences corresponding to PLMVd-derived siRNAs, which makes up 11.2% of the sequences of the infected library. These siRNAs contain mainly 21-22 nucleotide RNAs and are equivalently distributed between the plus and the minus polarities of the viroid. They cover the complete viroid genome, although the amount varies depending on the regions. These regions do not necessarily correlate with the double-stranded requirement to be a substrate for Dicer-like enzymes. We noted that some sequences encompass the hammerhead self-cleavage site, indicating that the circular conformers could be processed by the RNA-silencing machinery. Finally, a bias in the relative abundance of the nature of the 5' nucleotides was observed (A, U >> G, C). Conclusions The approach used provided us a quantitative representation of the PLMVd-derived siRNAs retrieved from infected peach trees. These siRNAs account for a relatively large proportion of the small non-coding RNAs. Surprisingly, the siRNAs from some regions of the PLMVd genome appear over-represented, although these

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

    PubMed

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

    2014-01-10

    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. 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. 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 potential confounding factors

  19. High prevalence of latent tuberculosis infection among injection drug users in Tijuana, Mexico

    PubMed Central

    Garfein, R. S.; Lozada, R.; Liu, L.; Laniado-Laborin, R.; Rodwell, T. C.; Deiss, R.; Alvelais, J.; Catanzaro, A.; Chiles, P. G.; Strathdee, S. A.

    2009-01-01

    Summary BACKGROUND We studied prevalence and correlates of latent tuberculosis infection (LTBI) among injection drug users (IDUs) in Tijuana, Mexico, where tuberculosis (TB) is endemic. METHODS IDUs aged ⩾18 years were recruited via respondent-driven sampling (RDS) and underwent standardized interviews, human immunodeficiency virus (HIV) antibody testing and LTBI screening using QuantiFERON®-TB Gold In-Tube, a whole-blood interferon-gamma release assay (IGRA). LTBI prevalence was estimated and correlates were identified using RDS-weighted logistic regression. RESULTS Of 1020 IDUs, 681 (67%) tested IGRA-positive and 44 (4%) tested HIV-positive. Mean age was 37 years, 88% were male and 98% were Mexican-born. IGRA positivity was associated with recruitment nearest the US border (aOR 1.64, 95%CI 1.09–2.48), increasing years of injection (aOR 1.20/5 years, 95%CI 1.07–1.34), and years lived in Tijuana (aOR 1.10/5 years, 95%CI 1.03–1.18). Speaking some English (aOR 0.38, 95%CI 0.25–0.57) and injecting most often at home in the past 6 months (aOR 0.68, 95%CI 0.45–0.99) were inversely associated with IGRA positivity. DISCUSSION Increased LTBI prevalence among IDUs in Tijuana appears to be associated with greater drug involvement. Given the high risk for HIV infection among Tijuana’s IDUs, interventions are urgently needed to prevent HIV infection and treat LTBI among IDUs before these epidemics collide. PMID:19383197

  20. Nerve growth factor antibody stimulates reactivation of ocular herpes simplex virus type 1 in latently infected rabbits.

    PubMed

    Hill, J M; Garza, H H; Helmy, M F; Cook, S D; Osborne, P A; Johnson, E M; Thompson, H W; Green, L C; O'Callaghan, R J; Gebhardt, B M

    1997-06-01

    Anti-nerve growth factor (anti-NGF) antibody has been shown to induce reactivation of latent herpes simplex virus type 1 (HSV-1) in vitro. We found that systemically administered anti-NGF induces ocular shedding of HSV-1 in vivo in rabbits harboring latent virus. Rabbits in which HSV-1 latency had been established were given intravenous injections of goat anti-NGF serum daily for 10 days beginning 42 days after primary viral infection. Tears were assayed for virus for 12 days beginning on the day of the first injection. All eight rabbits given high titer anti-NGF had infectious virus in their tears at least once during the 12-day period. Fifteen of 16 eyes were positive and the average duration of viral shedding for these eyes was 4.0 days. Latently infected rabbits receiving daily injections of nonimmune goat serum or saline for 10 consecutive days were controls. Only six of the 16 (38%) eyes from rabbits receiving nonimmune goat serum shed virus. Only one of 12 eyes from untreated rabbits shed virus. Sera from control rabbits had no detectable anti-NGF activity; titers in anti-NGF-treated rabbits ranged between 1:1000 and 1:10,000. NGF deprivation may act as a neuronal stressor and may share a common second messenger pathway with heat- or cold-stress induced reactivation of latent HSV-1.

  1. Active and latent ovine herpesvirus-2 (OvHV-2) infection in a herd of captive white-tailed deer (Odocoileus virginianus).

    PubMed

    Palmer, M V; Thacker, T C; Madison, R J; Koster, L G; Swenson, S L; Li, H

    2013-01-01

    Malignant catarrhal fever (MCF) is the clinical manifestation of infection of certain ruminant species with one of a group of pathogenic gammaherpesviruses known as MCF viruses. Cattle and numerous exotic ruminant species are susceptible to clinical disease that may be sporadic or occasionally epidemic in nature. The most common MCF virus worldwide is ovine herpesvirus (OvHV)-2. Reservoir hosts such as sheep, carry and excrete OvHV-2, but do not develop clinical signs, while clinically susceptible species develop severe and often fatal disease. The existence of latent infection in clinically susceptible hosts is poorly understood, but is documented in some ruminant species. Twenty-six animals from a captive herd of white-tailed deer (Odocoileus virginianus) died and were examined from October 2006 to December 2010. Fifteen of these animals (58%) showed clinical signs and gross and microscopical lesions consistent with MCF, while 11 (42%) did not. Polymerase chain reaction (PCR) amplification yielded product consistent with OvHV-2 DNA in samples of spleen from all 26 deer. To examine the possibility of latent infection in this herd, peripheral blood mononuclear cells were examined by PCR for OvHV-2 DNA, and the test was positive in 23/32 (72%) clinically normal deer. Archived serum samples were used to examine the history of MCF exposure in the herd using a competitive enzyme-linked immunosorbent assay, which demonstrated that 10/40 (25%) deer tested had MCF viral antibodies, with nine deer being seropositive over multiple years. Combined with previous observations in deer and other species, these results suggest the existence of latent infection of white-tailed deer with OvHV-2. Published by Elsevier Ltd.

  2. 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

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

    PubMed Central

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

    2016-01-01

    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

  4. 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.

  5. Methodological considerations for economic modelling of latent tuberculous infection screening in migrants.

    PubMed

    Shedrawy, J; Siroka, A; Oxlade, O; Matteelli, A; Lönnroth, K

    2017-09-01

    Tuberculosis (TB) in migrants from endemic to low-incidence countries results mainly from the reactivation of latent tuberculous infection (LTBI). LTBI screening policies for migrants vary greatly between countries, and the evidence on the cost-effectiveness of the different approaches is weak and heterogeneous. The aim of this review was to assess the methodology used in published economic evaluations of LTBI screening among migrants to identify critical methodological options that must be considered when using modelling to determine value for money from different economic perspectives. Three electronic databases were searched and 10 articles were included. There was considerable variation across this small number of studies with regard to economic perspective, main outcomes, modelling technique, screening options and target populations considered, as well as in parameterisation of the epidemiological situation, test accuracy, efficacy, safety and programme performance. Only one study adopted a societal perspective; others adopted a health care or wider government perspective. Parameters representing the cascade of screening and treating LTBI varied widely, with some studies using highly aspirational scenarios. This review emphasises the need for a more harmonised approach for economic analysis, and better transparency in how policy options and economic perspectives influence methodological choices. Variability is justifiable for some parameters. However, sufficient data are available to standardise others. A societal perspective is ideal, but can be challenging due to limited data. Assumptions about programme performance should be based on empirical data or at least realistic assumptions. Results should be interpreted within specific contexts and policy options, with cautious generalisations.

  6. Adherence to Latent Tuberculosis Infection Treatment in a Population with a High Number of Refugee Children.

    PubMed

    Rogo, Tanya; Eleanya, Cynthia; Hirway, Priya; Pelland, Doreen; Lewis, Carol; Dennehy, Penelope; Losikoff, Phyllis

    2017-02-01

    Refugee populations in the US have a higher reported prevalence of latent tuberculosis infection (LTBI). The objective of this study was to assess adherence to LTBI treatment in refugee and non-refugee children living in Rhode Island. This was a retrospective review of LTBI patients seen in the Hasbro Pediatric Tuberculosis Clinic between August 2009 and September 2011. Of 120 patients with LTBI, 93% were foreign-born and 30% were refugees. Overall, 94 children (78.3%) completed therapy. Higher rates of treatment completion were seen among patients who were female, referred within the same hospital system, used an interpreter, and did not report side effects. Refugees attended more scheduled visits compared to non-refugees (p=0.019). Overall rates of completion of LTBI treatment were high in this population. Better adherence to clinic visits, likely due to the increased support and care coordination provided to the refugee children, improved treatment completion rates. [Full article available at http://rimed.org/rimedicaljournal-2017-02.asp].

  7. Preventive therapy for latent tuberculosis infection-the promise and the challenges.

    PubMed

    Fox, G J; Dobler, C C; Marais, B J; Denholm, J T

    2017-03-01

    Around one third of the world's population may harbour latent tuberculosis infection (LTBI), an asymptomatic immunological state that confers a heightened risk of subsequently developing tuberculosis (TB). Effectively treating LTBI will be essential if the End TB Strategy is to be realized. This review evaluates the evidence in relation to the effectiveness of preventive antibiotic therapy to treat LTBI due to both drug-susceptible and drug-resistant bacteria. Current national and international preventive therapy guidelines are summarized, as well as ongoing randomized trials evaluating regimens to prevent drug-resistant TB. Populations that may benefit most from screening and treatment for LTBI include close contacts of patients with TB (particularly children under 5 years of age) and individuals with substantial immunological impairment. The risks and benefits of treatment must be carefully balanced for each individual. Electronic decision support tools offer one way in which clinicians can help patients to make informed decisions. Modelling studies indicate that the expanded use of preventive therapy will be essential to achieving substantial reductions in the global TB burden. However, the widespread scale-up of screening and treatment will require careful consideration of cost-effectiveness, while ensuring the drivers of ongoing disease transmission are also addressed.

  8. 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

  9. Evaluation of latent tuberculous infection and treatment completion for refugees in Philadelphia, PA, 2010-2012.

    PubMed

    Subedi, P; Drezner, K A; Dogbey, M C; Newbern, E C; Yun, K; Scott, K C; Garland, J M; Altshuler, M J; Johnson, C C

    2015-05-01

    Philadelphia, PA, USA. To compare the evaluation and treatment of latent tuberculous infection (LTBI) in refugees seen at member clinics of the Philadelphia Refugee Health Collaborative (PRHC) vs. non-PRHC clinics. Refugees with Class B (non-communicable) tuberculosis (TB) admitted to the United States from 2010 to 2012 who were being treated at PRHC clinics were compared to those treated at non-PRHC clinics. Odds ratios (ORs) for attending a follow-up appointment, completing treatment, and time from arrival to the United States to the first TB screening test were calculated. Of the 2094 refugees who arrived in Philadelphia in 2010-2012, the Philadelphia Department of Public Health was notified of 149 who required additional evaluation for TB. Among these, 57 (38.3%) were confirmed to have LTBI, and none were diagnosed with active TB. All LTBI cases were recommended for anti-tuberculosis prophylaxis and 43 (75.4%) completed treatment. Refugees receiving care from PRHC clinics were more likely to be screened within 30 days of arrival (OR 4.70, 95%CI 2.12-10.44), attend a follow-up appointment (OR 4.53, 95%CI 1.36-16.27), and complete treatment (OR 9.44, 95%CI 2.39-37.3). Refugees who attended PRHC clinics were more likely to be evaluated promptly and to complete LTBI treatment. The PRHC clinics serve as a model for communities seeking to improve refugee health care.

  10. Utilization of a latent tuberculosis infection referral system by newly resettled refugees in central Ohio.

    PubMed

    Kowatsch-Beyer, K; Norris-Turner, A; Love, R; Denkowski, P; Wang, S-H

    2013-03-01

    A resettlement medical screening program that refers refugees with a positive tuberculin skin test (TST) to a public health tuberculosis (TB) clinic for evaluation for latent tuberculosis infection (LTBI). To identify the proportion of refugees that were TST-positive, how many attended after referral for medical evaluation, what characteristics influenced follow-up, and whether programmatic changes would increase follow-up rates. Refugee characteristics and follow-up information were extracted from the resettlement medical records of 224 adult refugees screened in Columbus, Franklin County, Ohio, in 2008. Programmatic modifications in the referral system were implemented in December 2010. Of 224 refugees screened, 115 (51%) had a TST induration ≥ 5 mm, 113 (98.3%) were referred and 60 (53.1%) attended the Columbus Public Health (CPH) TB clinic for evaluation. Resettling from East Asia (Myanmar, Viet Nam; OR 12.48, 95%CI 2.32-67.06) and TST induration size ≥ 10 mm (OR 9.38, 95%CI 1.41-62.26) were significantly associated with follow-up at the CPH. Implementation of scheduled appointments, telephone reminders and transportation arrangements increased follow-up to 93.5%. Collaborative strategies can improve follow-up rates of TST-positive refugees during resettlement medical screening, facilitate LTBI treatment and prevent the development of active TB.

  11. Elevated Circulating Concentrations of Interferon-Gamma in Latent Tuberculosis Infection

    PubMed Central

    Huaman, Moises A.; Deepe, George S.; Fichtenbaum, Carl J.

    2016-01-01

    Background Latent tuberculosis infection (LTBI) has been associated with increased immune activation. We assessed circulating concentrations of interferon-gamma in persons with LTBI. Methods We used the 2011–2012 National Health Nutritional Examination Survey (NHANES) to identify adults with and without LTBI by QuantiFERON®-TB Gold In-Tube (QFT) results. Non-LTBI persons were 1:1 age-, gender-, and race-matched to LTBI persons using propensity scores. We compared the plasma concentrations of interferon-gamma measured from the unstimulated, negative control QFT tube between LTBI and non-LTBI persons. We used Mann-Whitney tests and ordered logistic regressions for comparisons. Results There were 430 LTBI and 430 non-LTBI matched persons included in the analysis. LTBI was associated with higher circulating concentrations of interferon-gamma (median, 3 pg/mL; IQR, 2 – 5) compared to non-LTBI (median, 2.5 pg/mL; IQR, 1.5 – 3.5); P < 0.001. LTBI remained associated with higher interferon-gamma concentrations after adjusting for age, gender, race, diabetes, hypertension, tobacco use, HIV status, body mass index, lipid profile, and lymphocyte count (odds ratio, 1.79, 95% CI, 1.26 – 2.53). Results remained similar when tuberculin skin testing defined LTBI. Conclusions LTBI was associated with increased circulating interferon-gamma concentrations. Future studies are needed to further characterize immune activation in LTBI and its potential long-term consequences. PMID:27853753

  12. Resistance, health, and latent tuberculosis infection: Mexican immigrants at the U.S.-Mexico border.

    PubMed

    McEwen, Marylyn Morris; Boyle, Joyceen

    2007-01-01

    Mexican immigrants living in the U.S.-Mexico border region are confronted with different national explanations about latent tuberculosis infection (LTBI) and preventive treatment. The purpose of this study was to explore how a group of Mexican immigrant women (N = 8) at risk of LTBI treatment failure interpreted and ultimately resisted LTBI preventive treatment. A critical ethnographic methodology, grounded in asymmetrical power relations that are historically embedded within the U.S.-Mexico border culture, was used to examine the encounters between the participants and the health care provider. The study findings are discussed from the perspective of women who experienced oppression and resistance in the U.S.-Mexico border region, providing an account of how Mexican immigrant women become entangled in U.S.-Mexico TB health policies and through resistance manage to assert control over health care choices. In the context of the U.S.-Mexico border region, health care professionals must be skilled at minimizing asymmetrical power relations and use methods that elicit immigrant voices in reconciling differences in health beliefs and practices.

  13. Normal D-dimer levels in patients with latent tuberculosis infection.

    PubMed

    Shitrit, D; Izbicki, G; Shitrit, A Bar-Gil; Raz, M; Sulkes, J; Kramer, M R

    2005-01-01

    Studies have demonstrated a link between acute pulmonary tuberculosis and a hypercoagulable state, but there are no data on the coagulation state of patients with latent tuberculosis infection (LTI). The present prospective observational study was designed to help fill this gap. The sample included 84 patients (high school students and adults) with suspected LTI referred for the purified protein derivative (PPD) test. Results were read according to the criteria of the American Thoracic Society. Blood samples were collected at admission and assayed for D-dimer, the marker of the coagulation state, with the quantitative Miniquant test. D-dimer values were correlated with the PPD status and clinical parameters. Fifty-seven patients tested positive for LTI and 27 tested negative. There was no significant difference in D-dimer level between these groups (341 +/- 106 and 360 +/- 60 microg/ml, respectively). No significant correlation was found between D-dimer level and PPD status, patient age or occupation (health care worker or not), or clinical indication for the tuberculin test. The normal D-dimer levels in this series suggest that low-level inflammations such as LTI do not lead to a hypercoagulable state.

  14. Adverse effects of isoniazid preventative therapy for latent tuberculosis infection: a prospective cohort study.

    PubMed

    Denholm, Justin T; McBryde, Emma S; Eisen, Damon P; Penington, Jocelyn S; Chen, Caroline; Street, Alan C

    2014-01-01

    Isoniazid preventative therapy (IPT) is a widely used intervention for treatment of latent tuberculosis infection (LTBI), particularly in patients at high risk for reactivation. While treatment-limiting adverse effects have been well studied, few prospective studies have considered the range of adverse effects that patients may experience with IPT. All patients commencing treatment for LTBI were prospectively enrolled in an ongoing database of LTBI treatment outcomes particularly related to adverse effects, treatment adherence, and treatment completion. Data on the first 100 patients who were prescribed IPT are presented. Fifty-six patients reported at least one adverse effect at some stage during treatment, with six experiencing at least one World Health Organization (WHO) Grade 3-4 adverse effect. Increased age was significantly associated with risk of adverse effects (odds ratio [OR] =1.05 per year; confidence interval [CI] of 1.02-1.08=95%). Eighty-five patients had documented completion of therapy locally, with ten patients ceasing IPT due to adverse effects. This report highlights a variety of somatic adverse effects that occurred in a real-world cohort of patients receiving IPT. While adverse effects were frequently identified in this study, the considerable majority were low grade and transient. Despite frequent adverse effects of LTBI in our treatment cohort, the study demonstrated high levels of treatment adherence and completion.

  15. IL-10 restricts memory T cell inflation during cytomegalovirus infection.

    PubMed

    Jones, Morgan; Ladell, Kristin; Wynn, Katherine K; Stacey, Maria A; Quigley, Máire F; Gostick, Emma; Price, David A; Humphreys, Ian R

    2010-09-15

    The beta-herpesvirus CMV induces a substantial and progressive expansion of virus-specific memory CD8 T cells, which protect the host against viral reactivation from latency. In this paper, we report that this expansion, or "inflation," of memory T cells is amplified dramatically during mouse CMV infection of IL-10 knockout (IL-10(-/-)) mice. T cells from IL-10(-/-) mice were oligoclonal, exhibited a highly activated phenotype, expressed antiviral cytokines, and degranulated in response to cognate Ag encounter ex vivo. Moreover, latent viral load was reduced in IL-10(-/-) mice. Importantly, these results were recapitulated by IL-10R blockade during chronic/latent infection of wild-type mice. These data demonstrate that regulatory immune mechanisms can influence CMV-specific T cell memory and suggest a possible rationale for the acquisition of functional IL-10 orthologs by herpesviruses.

  16. Relevance of latent TB infection in areas of high TB prevalence.

    PubMed

    Sharma, Surendra K; Mohanan, Sandeep; Sharma, Abhishek

    2012-09-01

    About one-third of the world population has latent TB infection (LTBI), the majority of which is distributed in 22 high-burden countries. Early diagnosis and treatment of active TB remains the top priority in resource-poor countries with high TB prevalence. Notwithstanding, because LTBI contributes significantly to the pool of active TB cases later on, its diagnosis and treatment is essential, especially in high-risk groups. The lack of a gold standard and several limitations of currently available tools, namely the tuberculin skin test and interferon-γ release assays, are major constraints for LTBI diagnosis. In areas with high TB prevalence, interferon-γ release assays have not shown superiority over the conventional tuberculin skin test and are yet to be systematically studied. Decisions regarding LTBI treatment with isoniazid preventive therapy should be made, keeping in mind the high prevalence of isoniazid resistance in these settings. Although efforts to shorten the LTBI treatment duration are encouraging, most trials have focused on adherence and toxicity. Future trials on short-duration regimens in high-burden settings should address drug efficacy issues as well. LTBI management, therefore, should comprise a targeted screening approach and individualization of LTBI treatment protocols. In addition, efforts should focus on airborne infection control measures in high-burden countries. A high prevalence of drug-resistant TB, the HIV epidemic, and delays in the diagnosis of active TB cases are other major concerns in areas of high TB prevalence. There is ample space for further research in these countries, whose outcomes may strengthen future national guidelines.

  17. Short-Course Therapy with Daily Rifapentine in a Murine Model of Latent Tuberculosis Infection

    PubMed Central

    Zhang, Tianyu; Zhang, Ming; Rosenthal, Ian M.; Grosset, Jacques H.; Nuermberger, Eric L.

    2009-01-01

    Rationale: Regimens recommended to treat latent tuberculosis infection (LTBI) are 3 to 9 months long. A 2-month rifampin+pyrazinamide regimen is no longer recommended. Shorter regimens are highly desirable. Because substituting rifapentine for rifampin in the standard regimen for active tuberculosis halves the treatment duration needed to prevent relapse in mice, we hypothesized daily rifapentine-based regimens could shorten LTBI treatment to 2 months or less. Objectives: To improve an existing model of LTBI chemotherapy and evaluate the efficacy of daily rifapentine-based regimens. Methods: Mice were immunized with a more immunogenic recombinant Bacille Calmette-Guérin strain (rBCG30) and received very low-dose aerosol infection with Mycobacterium tuberculosis to establish a stable lung bacterial burden below 104 CFU without drug treatment. Mice received a control (isoniazid alone, rifampin alone, rifampin+isoniazid, rifampin+pyrazinamide) or test (rifapentine alone, rifapentine+isoniazid, rifapentine+pyrazinamide, rifapentine+isoniazid+pyrazinamide) regimen for 8 weeks. Rifamycin doses were 10 mg/kg/d, analogous to the same human doses. Outcomes were biweekly lung CFU counts and relapse after 4 to 8 weeks of treatment. Measurements and Main Results: M. tuberculosis CFU counts remained stable around 3.65 log10 in immunized, untreated mice. Isoniazid or rifampin left all or most mice culture-positive at week 8. Rifampin+isoniazid cured 0 and 53% of mice and rifampin+pyrazinamide cured 47 and 100% of mice in 4 and 8 weeks, respectively. Rifapentine-based regimens were more active than rifampin+isoniazid and indistinguishable from rifampin+pyrazinamide. Conclusions: In this improved murine model of LTBI chemotherapy with very low lung burden, existing regimens were well represented. Daily rifapentine-based regimens were at least as active as rifampin+pyrazinamide, suggesting they could effectively treat LTBI in 6 to 8 weeks. PMID:19729664

  18. Role for Tumor Necrosis Factor Alpha in Murine Cytomegalovirus Transcriptional Reactivation in Latently Infected Lungs

    PubMed Central

    Simon, Christian O.; Seckert, Christof K.; Dreis, Doris; Reddehase, Matthias J.; Grzimek, Natascha K. A.

    2005-01-01

    Interstitial pneumonia is a major clinical manifestation of primary or recurrent cytomegalovirus (CMV) infection in immunocompromised recipients of a bone marrow transplant. In a murine model, lungs were identified as a prominent site of CMV latency and recurrence. Pulmonary latency of murine CMV is characterized by high viral genome burden and a low incidence of variegated immediate-early (IE) gene expression, reflecting a sporadic activity of the major IE promoters (MIEPs) and enhancer. The enhancer-flanking promoters MIEP1/3 and MIEP2 are switched on and off during latency in a ratio of ∼2:1. MIEP1/3 latency-associated activity generates the IE1 transcript of the ie1/3 transcription unit but not the alternative splicing product IE3 that encodes the essential transactivator of early gene expression. Splicing thus appeared to be an important checkpoint for maintenance of latency. In accordance with previous work of others, we show here that signaling by the proinflammatory cytokine tumor necrosis factor alpha (TNF-α) activates IE1/3 transcription in vivo. As an addition to current knowledge, Poisson distribution analysis revealed an increased incidence of IE1/3 transcriptional events as well as a higher amount of transcripts per event. Notably, TNF-α promoted the splicing to IE3 transcripts, but transcription did not proceed to the M55/gB early gene. Moreover, the activated transcriptional state induced by TNF-α did not predispose latently infected mice to a higher incidence of virus recurrence after hematoablative treatment. In conclusion, TNF-α is an important inductor of IE gene transcriptional reactivation, whereas early genes downstream in the viral replicative cycle appear to be the rate-limiting checkpoint(s) for virus recurrence. PMID:15596827

  19. Screening of health-care workers for latent tuberculosis infection in a Tertiary Care Hospital.

    PubMed

    Janagond, Anand Bimari; Ganesan, Vithiya; Vijay Kumar, G S; Ramesh, Arunagiri; Anand, Prem; Mariappan, M

    2017-01-01

    Health-care workers (HCWs) are at increased risk of acquiring tuberculosis (TB) than the general population. While national-level data on the burden of TB in general population is available from reliable sources, nationally representative data on latent tuberculosis infection (LTBI) burden in HCWs in the high burden countries is lacking. A prospective study was carried out to assess the risk of TB infection among HCWs who directly engage in medical duties. HCWs were recruited between January 2014 and December 2015. A structured questionnaire was used for risk assessment of TB infection among HCWs, including sociodemographic characteristics (e.g., age, gender, period of professional work, and employed position), knowledge of TB prevention and control, and history of professional work. A single-step tuberculin skin test (TST) using 5 international units (IU; 0.1 ml) of tuberculin (purified protein derivative from Mycobacterium bovis Bacillus Calmette-Guérin [BCG]). TB infection was determined using a TST induration ≥10 mm as a cutoff point for TST positivity. TST-positive participants were further subjected to detailed clinical evaluation and chest radiography to rule out active TB. The associations between TB infection and the sociodemographic characteristics, duration of possible exposure to TB while on medical duties, BCG vaccination, and knowledge about TB were estimated using Chi-square test. A two-sided P < 0.05 indicated statistical significance. A total of 206 eligible HCWs signed the informed consent and completed the questionnaires between January 2014 and December 2015. The age of the participants ranged from 18 to 71 years, with a mean age of 27.13 years. TST induration size (mean 6.37 mm) the TST results suggested that 36.8% (76/206) were infected with TB using a TST induration ≥10 mm as a cut-off point. All 76 TST-positive HCWs showed no evidence of active TB in clinical evaluation and chest radiography. However, during the study, two HCWs

  20. Interferon Gamma Release Assays for the Diagnosis of Latent TB Infection in HIV-Infected Individuals in a Low TB Burden Country

    PubMed Central

    Ní Cheallaigh, Clíona; Fitzgerald, Ian; Grace, Jacinta; Jagjit Singh, Gurmit; El-Eraki, Nahla; Gibbons, Noel; Keane, Joseph; Rogers, Thomas R.; Clarke, Susan; Bergin, Colm

    2013-01-01

    Background Interferon gamma release assays (IGRAs) are used to diagnose latent tuberculosis infection. Two IGRAs are commercially available: the Quantiferon TB Gold In Tube (QFT-IT) and the T-SPOT.TB. There is debate as to which test to use in HIV+ individuals. Previous publications from high TB burden countries have raised concerns that the sensitivity of the QFT-IT assay, but not the T-SPOT.TB, may be impaired in HIV+ individuals with low CD4+ T-cell counts. We sought to compare the tests in a low TB burden setting. Methodology/Principal Findings T-SPOT.TB, QFT-IT, and tuberculin skin tests (TST) were performed in HIV infected individuals. Results were related to patient characteristics. McNemar’s test, multivariate regression and correlation analysis were carried out using SPSS (SPSS Inc). 256 HIV infected patients were enrolled in the study. The median CD4+ T-cell count was 338 cells/µL (range 1–1328). 37 (14%) patients had a CD4+ T-cell count of <100 cells/µL. 46/256 (18% ) of QFT-IT results and 28/256 (11%) of T-SPOT.TB results were positive. 6 (2%) of QFT-IT and 18 (7%) of T-SPOT.TB results were indeterminate. An additional 9 (4%) of T-SPOT.TB results were unavailable as tests were not performed due to insufficient cells or clotting of the sample. We found a statistically significant association between lower CD4+ T-cell count and negative QFT-IT results (OR 1.055, p = 0.03), and indeterminate/unavailable T-SPOT.TB results (OR 1.079, p = 0.02). Conclusions/Significance In low TB prevalence settings, the QFT-IT yields more positive and fewer indeterminate results than T-SPOT.TB. Negative results on the QFT-IT and indeterminate/unavailable results on the T-SPOT.TB were more common in individuals with low CD4+ T-cell counts. PMID:23382842

  1. Molecular analysis of herpes simplex virus type 1 during epinephrine-induced reactivation of latently infected rabbits in vivo.

    PubMed Central

    Bloom, D C; Devi-Rao, G B; Hill, J M; Stevens, J G; Wagner, E K

    1994-01-01

    Infectious virus assays and PCR amplification of DNA and RNA were used to investigate herpes simplex virus (HSV) DNA replication and gene expression in the rabbit corneal model for virus reactivation in vivo. We used carefully defined latency-associated transcript-negative (LAT-) and LAT+ promoter mutants of the 17syn+ strain of HSV type 1. In agreement with earlier studies using a more extensive LAT- deletion mutant, the 17 delta Pst(LAT-) virus reactivated with extremely low frequency upon epinephrine induction. In contrast to our findings with murine latency models, amounts of viral DNA recovered from rabbit ganglia latently infected with either LAT+ or LAT- virus were equivalent. Also in contrast with the murine models, no net increase in viral DNA was seen in latently infected rabbit trigeminal ganglia induced to reactivate in vivo by iontophoresis of epinephrine. Despite this, transcription of lytic-phase genes could be detected within 4 h following induction of rabbits latently infected with either LAT+ or LAT- virus; this transcription diminished by 16 h following induction. These results are discussed in relation to models for the mechanism of action of HSV LAT. Images PMID:8107194

  2. 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. Published by Elsevier Ltd.

  3. EBV infection is common in gingival epithelial cells of the periodontium and worsens during chronic periodontitis.

    PubMed

    Vincent-Bugnas, Séverine; Vitale, Sébastien; Mouline, Caroline C; Khaali, Wafa; Charbit, Yves; Mahler, Patrick; Prêcheur, Isabelle; Hofman, Paul; Maryanski, Janet L; Doglio, Alain

    2013-01-01

    An amplifying role for oral epithelial cells (ECs) in Epstein-Barr Virus (EBV) infection has been postulated to explain oral viral shedding. However, while lytic or latent EBV infections of oro/nasopharyngeal ECs are commonly detected under pathological conditions, detection of EBV-infected ECs in healthy conditions is very rare. In this study, a simple non-surgical tissue sampling procedure was used to investigate EBV infection in the periodontal epithelium that surrounds and attaches teeth to the gingiva. Surprisingly, we observed that the gingival ECs of the periodontium (pECs) are commonly infected with EBV and may serve as an important oral reservoir of latently EBV-infected cells. We also found that the basal level of epithelial EBV-infection is significantly increased in chronic periodontitis, a common inflammatory disease that undermines the integrity of tooth-supporting tissues. Moreover, the level of EBV infection was found to correlate with disease severity. In inflamed tissues, EBV-infected pECs appear to be prone to apoptosis and to produce larger amounts of CCL20, a pivotal inflammatory chemokine that controls tissue infiltration by immune cells. Our discovery that the periodontal epithelium is a major site of latent EBV infection sheds a new light on EBV persistence in healthy carriers and on the role of this ubiquitous virus in periodontitis. Moreover, the identification of this easily accessible site of latent infection may encourage new approaches to investigate and monitor other EBV-associated disorders.

  4. New tools for detecting latent tuberculosis infection: evaluation of RD1-specific long-term response

    PubMed Central

    2009-01-01

    Background Interferon-gamma (IFN-γ) release assays (IGRAs) were designed to detect latent tuberculosis infection (LTBI). However, discrepancies were found between the tuberculin skin test (TST) and IGRAs results that cannot be attributed to prior Bacille Calmètte Guerin vaccinations. The aim of this study was to evaluate tools for improving LTBI diagnosis by analyzing the IFN-γ response to RD1 proteins in prolonged (long-term response) whole blood tests in those subjects resulting negative to assays such as QuantiFERON-TB Gold In tube (QFT-IT). Methods The study population included 106 healthy TST+ individuals with suspected LTBI (recent contact of smear-positive TB and homeless) consecutively enrolled. As controls, 13 healthy subjects unexposed to M. tuberculosis (TST-, QFT-IT-) and 29 subjects with cured pulmonary TB were enrolled. IFN-γ whole blood response to RD1 proteins and QFT-IT were evaluated at day 1 post-culture. A prolonged test evaluating long-term IFN-γ response (7-day) to RD1 proteins in diluted whole blood was performed. Results Among the enrolled TST+ subjects with suspected LTBI, 70/106 (66.0%) responded to QFT-IT and 64/106 (60.3%) to RD1 proteins at day 1. To evaluate whether a prolonged test could improve the detection of LTBI, we set up the test using cured TB patients (with a microbiologically diagnosed past pulmonary disease) who resulted QFT-IT-negative and healthy controls as comparator groups. Using this assay, a statistically significant difference was found between IFN-γ levels in cured TB patients compared to healthy controls (p < 0.006). Based on these data, we constructed a receiver operating characteristic (ROC) curve and we calculated a cut-off. Based on the cut-off value, we found that among the 36 enrolled TST+ subjects with suspected LTBI not responding to QFT-IT, a long term response to RD1 proteins was detected in 11 subjects (30.6%). Conclusion These results indicate that IFN-γ long-term response to M. tuberculosis RD1

  5. New tools for detecting latent tuberculosis infection: evaluation of RD1-specific long-term response.

    PubMed

    Butera, Ornella; Chiacchio, Teresa; Carrara, Stefania; Casetti, Rita; Vanini, Valentina; Meraviglia, Serena; Guggino, Giuliana; Dieli, Francesco; Vecchi, Marco; Lauria, Francesco N; Marruchella, Almerico; Laurenti, Patrizia; Singh, Mahavir; Caccamo, Nadia; Girardi, Enrico; Goletti, Delia

    2009-11-21

    Interferon-gamma (IFN-gamma) release assays (IGRAs) were designed to detect latent tuberculosis infection (LTBI). However, discrepancies were found between the tuberculin skin test (TST) and IGRAs results that cannot be attributed to prior Bacille Calmètte Guerin vaccinations. The aim of this study was to evaluate tools for improving LTBI diagnosis by analyzing the IFN-gamma response to RD1 proteins in prolonged (long-term response) whole blood tests in those subjects resulting negative to assays such as QuantiFERON-TB Gold In tube (QFT-IT). The study population included 106 healthy TST+ individuals with suspected LTBI (recent contact of smear-positive TB and homeless) consecutively enrolled. As controls, 13 healthy subjects unexposed to M. tuberculosis (TST-, QFT-IT-) and 29 subjects with cured pulmonary TB were enrolled. IFN-gamma whole blood response to RD1 proteins and QFT-IT were evaluated at day 1 post-culture. A prolonged test evaluating long-term IFN-gamma response (7-day) to RD1 proteins in diluted whole blood was performed. Among the enrolled TST+ subjects with suspected LTBI, 70/106 (66.0%) responded to QFT-IT and 64/106 (60.3%) to RD1 proteins at day 1. To evaluate whether a prolonged test could improve the detection of LTBI, we set up the test using cured TB patients (with a microbiologically diagnosed past pulmonary disease) who resulted QFT-IT-negative and healthy controls as comparator groups. Using this assay, a statistically significant difference was found between IFN-gamma levels in cured TB patients compared to healthy controls (p < 0.006). Based on these data, we constructed a receiver operating characteristic (ROC) curve and we calculated a cut-off. Based on the cut-off value, we found that among the 36 enrolled TST+ subjects with suspected LTBI not responding to QFT-IT, a long term response to RD1 proteins was detected in 11 subjects (30.6%). These results indicate that IFN-gamma long-term response to M. tuberculosis RD1 antigens may be

  6. Performance of an interferon-gamma release assay to diagnose latent tuberculosis infection during pregnancy.

    PubMed

    Lighter-Fisher, Jennifer; Surette, Ann-Marie

    2012-06-01

    To evaluate an interferon (IFN)-gamma release assay in diagnosing latent tuberculosis infection in pregnant adolescents and women at risk for exposure to Mycobacterium tuberculosis. This was a prospective study of women and adolescents receiving health care at Bellevue Hospital Outpatient Clinics in New York City. Each patient was assessed for M tuberculosis risk factors, had a tuberculin skin test placed, and an IFN-gamma release assay performed. The concordance between the tuberculin skin test and the IFN-gamma release assay was calculated and the results analyzed according to the likelihood of exposure to M tuberculosis. Mean mitogen IFN-γ levels were used across groups to compare reliability between trimesters and assay performance in pregnant compared with nonpregnant females of childbearing age. A total of 140 pregnant and 140 nonpregnant females were enrolled in the study. The IFN-gamma release assay was highly specific, and IFN-gamma release assay positivity was associated with a greater likelihood of exposure to M tuberculosis. The overall agreement between the tuberculin skin test and IFN-gamma release assay results was 88% for all pregnant patients, corresponding to a κ of 0.452 (confidence interval 0.26-0.64). Interferon-γ release from the mitogen did not appear to have any temporal association with pregnancy trimester in cross-sectional or longitudinal studies. The IFN-gamma release assay performed equally well in pregnant and nonpregnant females. The IFN-gamma release assay performed equally well in each trimester of pregnancy with comparable results to nonpregnant females. Interferon-gamma release assays are much more specific, at least as sensitive, and may be a better predictor of disease progression than the tuberculin skin test. : II.

  7. Highly Multiplexed Proteomic Analysis of Quantiferon Supernatants To Identify Biomarkers of Latent Tuberculosis Infection

    PubMed Central

    De Groote, Mary Ann; Higgins, Michael; Hraha, Thomas; Wall, Kirsten; Wilson, Michael L.; Sterling, David G.; Janjic, Nebojsa; Reves, Randall

    2016-01-01

    ABSTRACT The tests for diagnosing latent tuberculosis infection (LTBI) are limited by a poor predictive value for identifying people at the highest risk for progressing to active tuberculosis (TB) and have various sensitivities and specificities in different populations. Identifying a more robust signature for LTBI is important for TB prevention and elimination. A pilot study was conducted with samples from immigrants to the United States that were screened for LTBI by the three commercially approved tests, namely, the tuberculin skin test (TST), the Quantiferon-TB Gold in-tube (QFT-GIT), and the T-SPOT.TB (T-SPOT). QFT-GIT supernatants from 13 people with concordant positive results and 26 people with concordant negative results were analyzed via the highly multiplexed SOMAscan proteomic assay. The proteins in the stimulated supernatants that distinguished LTBI from controls included interleukin-2 (IL-2), monocyte chemotactic protein 2 (MCP-2), interferon gamma inducible protein-10 (IP-10), interferon gamma (IFN-γ), tumor necrosis factor superfamily member 14 (TNFSF14, also known as LIGHT), monokine induced by gamma interferon (MIG), and granzyme B (P <0.00001). In addition, antigen stimulation increased the expression of heparin-binding EGF-like growth factor (HB-EGF) and activin AB in LTBI samples. In nil tubes, LIGHT was the most significant marker (P <0.0001) and was elevated in LTBI subjects. Other prominent markers in nonstimulated QFT-GIT supernatants were the complement-3 components C3b, iC3b, and C3d, which were upregulated in LTBI and markedly decreased upon stimulation. We found known and novel proteins that warrant further studies for developing improved tests for LTBI, for predicting progression to active disease, and for discriminating LTBI from active TB. PMID:27852671

  8. Latent TB infection and pulmonary TB disease among patients with diabetes mellitus in Bandung, Indonesia.

    PubMed

    Koesoemadinata, Raspati C; McAllister, Susan M; Soetedjo, Nanny N M; Febni Ratnaningsih, Dwi; Ruslami, Rovina; Kerry, Sarah; Verrall, Ayesha J; Apriani, Lika; van Crevel, Reinout; Alisjahbana, Bachti; Hill, Philip C

    2017-02-01

    Screening and treatment of latent TB infection (LTBI) and TB disease could reduce diabetes mellitus (DM)-associated TB. We aimed to describe the prevalence of LTBI and pulmonary TB among patients with DM in a TB-endemic setting. Patients with DM attending a hospital and community centres in Bandung, Indonesia, underwent LTBI screening using interferon gamma release assay (IGRA). TB was investigated by sputum smear, culture and x-ray. TB contacts from a parallel study were age- and sex-matched to patients with DM to compare LTBI and TB disease prevalence. Of 682 patients with DM screened, 651 (95.5%) were eligible. Among 'TB disease-free' patients, LTBI prevalence was 38.9% (206/530; 95% CI 34.7-43.2). Patients with DM were less likely to be IGRA positive than TB contacts (38.6%, 54/140; 95% CI 30.5-46.6 vs 68.6%, 96/140; 95% CI 60.9-72.3: p<0.001); but had a higher disease prevalence (4.9%, 8/164; 95% CI 1.6-8.2 vs 1.2%, 2/164; 95% CI -0.5 to 2.9: p=0.054). Patients with DM in crowded households had increased risk of LTBI (AOR 1.71; 95% CI 1.19-2.45). LTBI prevalence in patients with DM was lower than in household contacts, but patients with DM were more likely to have TB disease. Further studies should explore possible benefits of LTBI screening and preventive therapy in patients with DM in TB-endemic settings.

  9. Latent Tuberculosis Infection Screening in Foreign-Born Populations: A Successful Mobile Clinic Outreach Model

    PubMed Central

    Zelenev, Alexei; Walton, Mary R.; Bruce, R. Douglas; Altice, Frederick L.

    2014-01-01

    Objectives. We evaluated the efficacy of a mobile medical clinic (MMC) screening program for detecting latent tuberculosis infection (LTBI) and active tuberculosis. Methods. A LTBI screening program in a MMC in New Haven, Connecticut, used medical surveys to examine risk factors and tuberculin skin test (TST) screening eligibility. We assessed clinically relevant correlates of total (prevalent; n = 4650) and newly diagnosed (incident; n = 4159) LTBI from 2003 to 2011. Results. Among 8322 individuals, 4159 (55.6%) met TST screening eligibility criteria, of which 1325 (31.9%) had TST assessed. Similar to LTBI prevalence (16.8%; 779 of 4650), newly diagnosed LTBI (25.6%; 339 of 1325) was independently correlated with being foreign-born (adjusted odds ratio [AOR] = 8.49; 95% confidence interval [CI] = 5.54, 13.02), Hispanic (AOR = 3.12; 95% CI = 1.88, 5.20), Black (AOR = 2.16; 95% CI = 1.31, 3.55), employed (AOR = 1.61; 95% CI = 1.14, 2.28), and of increased age (AOR = 1.04; 95% CI = 1.02, 1.05). Unstable housing (AOR = 4.95; 95% CI = 3.43, 7.14) and marijuana use (AOR = 1.57; 95% CI = 1.05, 2.37) were significantly correlated with incident LTBI, and being male, heroin use, interpersonal violence, employment, not having health insurance, and not completing high school were significantly correlated with prevalent LTBI. Conclusions. Screening for TST in MMCs successfully identifies high-risk foreign-born, Hispanic, working, and uninsured populations and innovatively identifies LTBI in urban settings. PMID:24922157

  10. Latent cytomegalovirus infection and innate immune function following a 75 km cycling time trial.

    PubMed

    LaVoy, Emily C P; Nieman, David C; Henson, Dru A; Shanely, R Andrew; Knab, Amy M; Cialdella-Kam, Lynn; Simpson, Richard J

    2013-10-01

    This study compared the acute immune response, inflammation, and lipid peroxidation to a 75 km cycling time trial in male athletes testing positive or negative for latent cytomegalovirus (CMV) infection. Trained cyclists (N = 20) were tested for CMV serostatus, and cycled 75 km on a mountainous course using indoor trainers with continuous workload monitoring. Pre-, post-, and 1 h post-exercise blood samples were analyzed for total blood leukocyte counts, blood granulocyte (GR) and monocyte (MO) phagocytosis (PHAG) and oxidative burst activity (OBA), four plasma cytokines, and plasma F2-isoprostanes. Forty percent of the subjects tested positive for CMV. No differences in subject characteristics were found between CMVpos and CMVneg groups. Mean power (57.3 ± 1.6, 59.4 ± 1.8 % maximal Watts, p = 0.803), heart rate (87.0 ± 1.0, 86.5 ± 1.3 % maximal heart rate, p = 0.376), and total time (2.56 ± 0.08, 2.60 ± 0.08 h, p = 0.744) to complete the 75 km cycling time trial did not differ between CMVpos and CMVneg groups. Whereas exercise induced significant changes in total blood leukocyte counts, GR and MO-PHAG, four plasma cytokines, and plasma F2-isoprostanes (p < 0.05, ω(2) > 0.03), these exercise-induced changes did not differ between CMVpos and CMVneg groups (p > 0.05, ω(2) < 0.01). CMV serostatus does not appear to influence these innate immune responses or markers of inflammation and lipid peroxidation in response to a single bout of heavy exertion.

  11. Detection of latent tuberculosis infection among migrant farmworkers along the US-Mexico border.

    PubMed

    Oren, E; Fiero, M H; Barrett, E; Anderson, B; Nuῆez, M; Gonzalez-Salazar, F

    2016-11-03

    Migrant farmworkers are among the highest-risk populations for latent TB infection (LTBI) in the United States with numerous barriers to healthcare access and increased vulnerability to infectious diseases. LTBI is usually diagnosed on the border using the tuberculin skin test (TST). QuantiFERON-TB Gold In-Tube (QFT-GIT) also measures immune response against specific Mycobacterium tuberculosis antigens. The objective of this study is to assess the comparability of TST and QFT-GIT to detect LTBI among migrant farmworkers on the border, as well as to examine the effects of various demographic and clinical factors on test positivity. Participants were recruited using mobile clinics on the San Luis US-Mexico border and tested with QFT-GIT and TST. Demographic profiles and clinical histories were collected. Kappa coefficients assessed agreement between TST and QFT-GIT using various assay cutoffs. Logistic regression examined factors associated with positive TST or QFT-GIT results. Of 109 participants, 59 of 108 (55 %) were either TST (24/71, 34 %) or QFT-GIT (52/106, 50 %) positive. Concordance between TST and QFT-GIT was fair (71 % agreement, ĸ = 0.38, 95 % CI: 0.15, 0.61). Factors associated with LTBI positivity included smoking (OR = 1.26, 95 % CI-1.01-1.58) and diabetes/high blood sugar (OR = 0.70, 95 % CI = 0.51-0.98). Test concordance between the two tests was fair, with numerous discordant results observed. Greater proportion of positives detected using QFT-GIT may help avoid LTBI under-diagnosis. Assessment of LTBI status on the border provides evidence whether QFT-GIT should replace the TST in routine practice, as well as identifies risk factors for LTBI among migrant populations.

  12. 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

  13. [Multi-centre study of the prevalence of latent tuberculosis infection amongst inmates in Spanish prisons].

    PubMed

    García-Guerrero, J; Marco Mouriño, A; Sáiz de la Hoya Zamácola, P; Vera-Remartínez, E J

    2010-02-01

    To study the prevalence of latent tuberculosis infection (LTBI) amongst inmates in Spanish prisons. Multi-centre, cross-sectional study; two stage sampling. Socio-demographic, prison and clinical variables were gathered. A univariate, bivariate and multivariate analysis was carried out using logistic regression with the variables that showed statistical significance. The odds ratio was calculated with a confidence interval of 95%. 378 patients. The Mantoux test (PPD) assessable in 90.2% was available. 91.2% men, 37.8% foreigners with average age of 35.9±10.3 years. Average stay in prison: 2 years, 28.7% had been > 5 years in prison. 49.6% entered prison in 2006 or before. 24.5% had a history of intravenous drug use (IDU). 50.4% presented LTBI that was associated with: age > 40 years (63.2 vs 43.8%; CI: 1.39-3.49; OR: 2.20; p=0.001); stay of > 5 years in prison (71.2 vs 41.3%; CI: 2.13-5.75; OR: 3.50; p<0.001); in prison since 2006 or before (58.1 vs 42.6%; CI: 1.22-2.88; OR:1.87; p=0.004); infected with HCV+ (66.3 vs 45.3%; CI:1.40-4.0; OR: 2.37; p=0.001). The logistic regression model confirmed the independent association of LTBI with: a) age > 40 years (OR: 1.76; CI: 1.08-2.87; p=0.024); and length of prison stay > 5 years (OR: 2.50; CI: 1.41-4.43; p=0.002). The prevalence of LTBI in prison is very high, especially amongst inmates over 40 and those who have been in prison for more than five years. To prevent the risk of progression to tuberculosis, treatment is recommended for those who require it along with the maintenance of control programmes for this pathology.

  14. Cultured Vestibular Ganglion Neurons Demonstrate Latent HSV1 Reactivation

    PubMed Central

    Roehm, Pamela C.; Camarena, Vladimir; Nayak, Shruti; Gardner, James B.; Wilson, Angus; Mohr, Ian; Chao, Moses V.

    2013-01-01

    Objectives/Hypothesis Vestibular neuritis is a common cause of both acute and chronic vestibular dysfunction. Multiple pathologies have been hypothesized to be the causative agent of vestibular neuritis; however, whether herpes simplex type I (HSV1) reactivation occurs within the vestibular ganglion has not been demonstrated previously by experimental evidence. We developed an in vitro system to study HSV1 infection of vestibular ganglion neurons (VGNs) using a cell culture model system. Study design basic science study. Results Lytic infection of cultured rat VGNs was observed following low viral multiplicity of infection (MOI). Inclusion of acyclovir suppressed lytic replication and allowed latency to be established. Upon removal of acyclovir, latent infection was confirmed with reverse-transcription polymerase chain reaction and by RNA fluorescent in situ hybridization for the latency-associated transcript (LAT). 29% cells in latently infected cultures were LAT positive. The lytic IPC27 transcript was not detected by reverse-transcription polymerase chain reaction (RT-PCR). Reactivation of HSV1 occurred at a high frequency in latently infected cultures following treatment with trichostatin A (TSA), a histone deactylase inhibitor. Conclusions VGNs can be both lytically and latently infected with HSV1. Furthermore, latently infected VGNs can be induced to reactivate using TSA. This demonstrates that reactivation of latent HSV1 infection in the vestibular ganglion can occur in a cell culture model, and suggests that reactivation of HSV1 infection a plausible etiologic mechanism of vestibular neuritis. PMID:21898423

  15. 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 Central

    Jamaluddin, Md Saha; Hu, Pei-Wen; Jan, Yih; Siwak, Edward B.

    2016-01-01

    Abstract 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

  16. A promoter of Epstein-Barr virus that can function during latent infection can be transactivated by EBNA-1, a viral protein required for viral DNA replication during latent infection.

    PubMed Central

    Sugden, B; Warren, N

    1989-01-01

    A viral promoter that functions on recombinant plasmids in cells immortalized by Epstein-Barr virus was identified and characterized. It is identical to that mapped on the viral genome by Bodescot et al. (M. Bodescot, M. Perricaudet, and P.J. Farrell, J. Virol. 61:3424-3430, 1987) which functions during the latent phase of the viral life cycle in some but not all cells to encode several latent viral gene products. Experiments with these plasmids indicated that this promoter requires the enhancer within oriP of Epstein-Barr virus in cis to function efficiently. They also indicated that it requires the EBNA-1 gene in trans to function efficiently. The EBNA-1 gene therefore positively affects both viral DNA replication (J.L. Yates, N. Warren, and B. Sugden, Nature [London] 313:812-815, 1985) and viral transcription. Images PMID:2542577

  17. Primary CD8+ T cells from elite suppressors effectively eliminate non-productively HIV-1 infected resting and activated CD4+ T cells.

    PubMed

    Buckheit, Robert W; Siliciano, Robert F; Blankson, Joel N

    2013-07-01

    Elite controllers or suppressors have the remarkable capacity to maintain HIV-1 plasma RNA levels below the limit of detection of clinical assays (<50 copies/mL) without therapy and have a lower frequency of latently infected cells compared to chronic progressors. While it is unclear how this reduced seeding of the reservoir is achieved, it is possible that effective CTL responses play an in important role in limiting the size of the latent reservoir. Herein, we demonstrate that primary CD8+ T cells from HLA-B*57/5801 elite suppressors were able to efficiently eliminate resting and activated primary CD4+ T cells shortly after viral entry and prior to productive infection. CD8+ T cells from elite suppressors were significantly more effective at eliminating these cells than CD8+ T cells from chronic progressors. Nonproductively infected CD4+ T cells may represent a subpopulation of cells that are precursors to latently infected cells; therefore, the effective elimination of these cells may partially explain why elite suppressors have a much lower frequency of latently infected cells compared to chronic progressors. Thus, a vaccine strategy that elicits early and potent CD8+ T cell responses may have the capacity to limit the seeding of the latent reservoir in HIV-1 infection.

  18. Assessment of latent tuberculosis infection in Takayasu arteritis with tuberculin skin test and Quantiferon-TB Gold test.

    PubMed

    Karadag, Omer; Aksu, Kenan; Sahin, Abdurrahman; Zihni, Figen Yargucu; Sener, Burcin; Inanc, Nevsun; Kalyoncu, Umut; Aydin, Sibel Zehra; Ascioglu, Sibel; Ocakci, Pinar Talu; Bilgen, Sule Apras; Keser, Gokhan; Inal, Vedat; Direskeneli, Haner; Calguneri, Meral; Ertenli, Ihsan; Kiraz, Sedat

    2010-09-01

    A possible relationship between Takayasu arteritis (TA) and tuberculosis (TB) has been suggested. An increased frequency of tuberculin skin test (TST) was observed in TA patients. Quantiferon-TB Gold test (QFT) is a new in vitro assay measuring interferon-gamma response to M. tuberculosis antigens and helpful in diagnosing latent TB infection. The aim of this study was to investigate latent TB infection among TA patients by the use of both TST and QFT Gold test. Ninety-four (male/female: 7/87) TA patients fulfilling ACR 1990 TA criteria from three different university hospitals in Turkey and 107 control subjects without inflammatory diseases were included in the study. Data about medical history (TA and TB) were collected for both groups. TST and QFT were performed. TST values > or =5 mm for TA patients and > or =15 mm for controls was accepted as TST positivity. Even though TA group was older (40 +/- 12 vs. 32 +/- 8, P < 0.001), there was no significant difference between TA patients and controls regarding demographic characteristics. Six TA patients and one control had a history of previous TB infection (P = 0.054). Although TST positivity was higher in TA group [55 patients (62.5%) vs. 24 controls (41.4%), P = 0.008], QFT positivity was similar between two groups [21 patients (22.3%) vs. 24 controls (22.4%), P > 0.05]. QFT was negative in two of six TA patients with previous TB history. Rate of latent TB infection in TA patients measured with QFT is no more than controls. QFT seems to be a good and favorable test compared with TST in detecting LTBI in TA.

  19. A viral function represses accumulation of transcripts from productive-cycle genes in mouse ganglia latently infected with herpes simplex virus.

    PubMed

    Chen, S H; Kramer, M F; Schaffer, P A; Coen, D M

    1997-08-01

    Latent infections of neurons by herpes simplex virus form reservoirs of recurrent viral infections that resist cure. In latently infected neurons, viral gene expression is severely repressed; only the latency-associated transcripts (LATs) are expressed abundantly. Using sensitive reverse transcriptase PCR assays, we analyzed the effects of a deletion mutation in the LAT locus on viral gene expression in latently infected mouse trigeminal ganglia. The deletion mutation, which reduced expression of the major LATs 10(5)-fold, resulted in a approximately 5-fold increase in accumulation of transcripts from the immediate-early gene encoding ICP4, an essential transactivator of viral gene expression. The LAT deletion also resulted in a >10-fold increase in the accumulation of transcripts from the early gene encoding thymidine kinase, whose expression during productive infection stringently depends on ICP4, and positively affected the correlation of the levels of these transcripts with the levels of ICP4 transcripts. We also detected transcripts antisense to ICP4 RNA, which were in substantial excess to ICP4 transcripts in ganglia latently infected with wild-type virus. In contrast to its effects on productive-cycle transcripts, the LAT deletion reduced the accumulation of these antisense transcripts approximately 15-fold. Thus, a viral function associated with the LAT locus represses the accumulation of transcripts from at least two productive-cycle genes in latently infected mouse ganglia. We discuss possible mechanisms and consequences of this repression.

  20. Effect of Pregnancy on Interferon Gamma Release Assay and Tuberculin Skin Test Detection of Latent TB Infection Among HIV-Infected Women in a High Burden Setting.

    PubMed

    LaCourse, Sylvia M; Cranmer, Lisa M; Matemo, Daniel; Kinuthia, John; Richardson, Barbra A; Horne, David J; John-Stewart, Grace

    2017-05-01

    Peripartum immunologic changes may affect latent tuberculosis infection (LTBI) diagnostic performance among HIV-infected women. HIV-infected women were serially tested with tuberculin skin test (TST) and interferon gamma release assay [QuantiFERON TB Gold In-tube (QFT)] in pregnancy and 6 weeks postpartum in Kenya. Prevalence, sensitivity and agreement, and correlates of QFT/TST positivity were assessed. Quantitative QFT mitogen and Mycobacterium tuberculosis antigen (Mtb-Ag) responses were compared by peripartum stage. Incidence of test conversion at 6 weeks postpartum was evaluated in baseline TST-/QFT- women. Among 100 HIV-infected women, median age was 26 years, median CD4 was 555 cells per cubic millimeter, and 88% were on antiretrovirals. More women were QFT+ than TST+ in both pregnancy (35.4% vs. 13.5%, P = 0.001) and postpartum (29.6% vs. 14.8%, P < 0.001). Among 18 consistently QFT+ women, 8 (44%) converted from TST- to TST+, with improved test agreement postpartum (56.9%, κ = 0.20 to 82.4%, κ = 0.60). Three initially QFT-/TST- women had test conversion (TST+ and/or QFT+), suggesting new infection (incidence 13.4/100 person-years). Mean QFT mitogen (4.46 vs. 7.64 IU/mL, P < 0.001) and Mtb-Ag (1.03 vs. 1.54 IU/mL, P = 0.03) responses were lower among all women retested in pregnancy vs. postpartum, and specifically among persistently QFT+ women (Mtb-Ag: 3.46 vs. 4.48 IU/mL, P = 0.007). QFT indeterminate rate was higher in pregnancy (16%) compared with postpartum (0%) because of lower mitogen response. QFT identified >2-fold more women with LTBI compared with TST in pregnancy and postpartum. Lower QFT Mtb-Ag and mitogen responses in pregnancy compared with postpartum suggest that pregnancy-associated immunologic changes may influence LTBI test performance.

  1. 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

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

    PubMed

    Ramji, Ramesh; Wong, Victor C; Chavali, Arvind K; Gearhart, Larisa M; Miller-Jensen, Kathryn

    2015-09-01

    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.

  3. Cellular Localization of Latent Murine Cytomegalovirus

    PubMed Central

    Koffron, Alan J.; Hummel, Mary; Patterson, Bruce K.; Yan, Shixian; Kaufman, Dixon B.; Fryer, Jonathan P.; Stuart, Frank P.; Abecassis, Michael I.

    1998-01-01

    Herpesviruses typically establish latent infection in their hosts. The cell(s) responsible for harboring latent virus, in most cases, is not known. Using immunofluorescence and PCR-in situ hybridization (PISH), a technique which combines the sensitivity of PCR with the localization and specificity of in situ hybridization, we provide the first direct evidence that endothelial cells are a major site of murine cytomegalovirus (MCMV) DNA in latently infected animals. These findings are consistent with existing knowledge of the biological behavior of CMV, in particular the transmission of latent CMV by solid organ and bone marrow transplantation, in both human and animal models. In addition, we have localized MCMV DNA in the lung alveolar macrophage and in bone marrow cells. Our findings confirm that bone marrow-derived hematopoietic cells are a site of CMV latency and further suggest that bone marrow may be a reservoir of infected progeny capable of migrating into the circulation and establishing latency in various tissues. These findings provide clearly needed insight into the site of latent infection which is central to an understanding of the mechanisms of reactivation. PMID:9420204

  4. Epigenotypes of latent herpesvirus genomes.

    PubMed

    Minarovits, J

    2006-01-01

    Epigenotypes are modified cellular or viral genotypes which differ in transcriptional activity in spite of having an identical (or nearly identical) DNA sequence. Restricted expression of latent, episomal herpesvirus genomes is also due to epigenetic modifications. There is no virus production (lytic viral replication, associated with the expression of all viral genes) in tight latency. In vitro experiments demonstrated that DNA methylation could influence the activity of latent (and/or crucial lytic) promoters of prototype strains belonging to the three herpesvirus subfamilies (alpha-, beta-, and gamma-herpesviruses). In vivo, however, DNA methylation is not a major regulator of herpes simplex virus type 1 (HSV-1, a human alpha-herpesvirus) latent gene expression in neurons of infected mice. In these cells, the promoter/enhancer region of latency-associated transcripts (LATs) is enriched with acetyl histone H3, suggesting that histone modifications may control HSV-1 latency in terminally differentiated, quiescent neurons. Epstein-Barr virus (EBV, a human gamma-herpesvirus) is associated with a series of neoplasms. Latent, episomal EBV genomes are subject to host cell-dependent epigenetic modifications (DNA methylation, binding of proteins and protein complexes, histone modifications). The distinct viral epigenotypes are associated with distinct EBV latency types, i.e., cell type-specific usage of latent EBV promoters controlling the expression of latent, growth transformation-associated EBV genes. The contribution of major epigenetic mechanisms to the regulation of latent EBV promoters is variable. DNA methylation contributes to silencing of Wp and Cp (alternative promoters for transcripts coding for the nuclear antigens EBNA 1-6) and LMP1p, LMP2Ap, and LMP2Bp (promoters for transcripts encoding transmembrane proteins). DNA methylation does not control, however, Qp (a promoter for EBNA1 transcripts only) in lymphoblastoid cell lines (LCLs), although in vitro

  5. 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

  6. Treatment of Latent Tuberculosis Infection: An Updated Network Meta-analysis.

    PubMed

    Zenner, Dominik; Beer, Netta; Harris, Ross J; Lipman, Marc C; Stagg, Helen R; van der Werf, Marieke J

    2017-08-15

    Treatment of latent tuberculosis infection (LTBI) is an important component of tuberculosis (TB) control, and this study updates a previous network meta-analysis of the best LTBI treatment options to inform public health action and programmatic management of LTBI. To evaluate the comparative efficacy and harms of LTBI treatment regimens aimed at preventing active TB among adults and children. PubMed, Embase, and Web of Science from indexing to 8 May 2017; clinical trial registries; and conference abstracts. No language restrictions were applied. Randomized controlled trials that evaluated human LTBI treatments and recorded at least 1 of 2 prespecified end points (hepatotoxicity and prevention of active TB). 2 investigators independently extracted data from eligible studies and assessed study quality according to a standard protocol. The network meta-analysis of 8 new and 53 previously included studies showed that isoniazid regimens of 6 months (odds ratio [OR], 0.65 [95% credible interval {CrI}, 0.50 to 0.83]) or 12 to 72 months (OR, 0.50 [CrI, 0.41 to 0.62]), rifampicin-only regimens (OR, 0.41 [CrI, 0.19 to 0.85]), rifampicin-isoniazid regimens of 3 to 4 months (OR, 0.53 [CrI, 0.36 to 0.78]), rifampicin-isoniazid-pyrazinamide regimens (OR, 0.35 [CrI, 0.19 to 0.61]), and rifampicin-pyrazinamide regimens (OR, 0.53 [CrI, 0.33 to 0.84]) were efficacious compared with placebo. Evidence existed for efficacy of weekly rifapentine-isoniazid regimens compared with no treatment (OR, 0.36 [CrI, 0.18 to 0.73]). No conclusive evidence showed that HIV status altered treatment efficacy. Evidence was sparse for many comparisons and hepatotoxicity outcomes, and risk of bias was high or unknown for many studies. Evidence exists for the efficacy and safety of 6-month isoniazid monotherapy, rifampicin monotherapy, and combination therapies with 3 to 4 months of isoniazid and rifampicin. U.K. National Institute for Health Research. (PROSPERO: CRD42016037871).

  7. Serial interferon-gamma release assays for the diagnosis of latent tuberculosis infection in patients treated with immunosuppressive agents.

    PubMed

    Kim, Kyeong-Hee; Lee, Sung-Won; Chung, Won-Tae; Kim, Byoung-Gwon; Woo, Kwang-Sook; Han, Jin-Yeong; Kim, Jeong-Man

    2011-10-01

    We assessed the efficacy of serial interferon-gamma release assays (IGRAs) for the diagnosis of latent tuberculosis infection (LTBI) in patients receiving immunosuppressive agents for treatment of rheumatic diseases in Korea. Of 276 patients who underwent consecutive screening with one of two IGRAs [QuantiFERON-TB Gold or QuantiFERON-TB Gold In-Tube], 66 patients were evaluated by the serial IGRA for detection of LTBI during therapy with immunosuppressive agents. Information on clinical diagnosis, medication, previous TB, blood cell count, tuberculin skin test, and interferon-gamma (IFN-γ) level measured by IGRA was collected. Of the 66 patients, the initial IGRA was positive in 24.2%, negative in 65.2%, and indeterminate in 10.6%. Forty-six patients (69.7%) showed consistent IGRA results during follow-up, and 13 patients (19.7%) had consistently positive results. IGRA conversion rate was 12.1% (8/66) and reversion rate was 4.5% (3/66). Conversion of IGRA results was only observed in ankylosing spondylitis patients, and the median interval between the two tests in patients with conversion was 8.5 months. The mean IFN-γ level in the group of patients with consistently positive IGRA results was higher than that in the group with inconsistently positive results, although this trend was not statistically significant (P=0.293). Indeterminate results were observed most frequently in patients with systemic lupus erythematosus. In patients receiving immunosuppressive agents, both IGRA conversions and reversions were observed. Serial IGRA testing may not be needed in patients with a positive initial IGRA result showing high IFN-γ levels, because of high consistency in the test results.

  8. Serial Interferon-gamma Release Assays for the Diagnosis of Latent Tuberculosis Infection in Patients Treated with Immunosuppressive Agents

    PubMed Central

    Lee, Sung-Won; Chung, Won-Tae; Kim, Byoung-Gwon; Woo, Kwang-Sook; Han, Jin-Yeong; Kim, Jeong-Man

    2011-01-01

    Background We assessed the efficacy of serial interferon-gamma release assays (IGRAs) for the diagnosis of latent tuberculosis infection (LTBI) in patients receiving immunosuppressive agents for treatment of rheumatic diseases in Korea. Methods Of 276 patients who underwent consecutive screening with one of two IGRAs [QuantiFERON-TB Gold or QuantiFERON-TB Gold In-Tube], 66 patients were evaluated by the serial IGRA for detection of LTBI during therapy with immunosuppressive agents. Information on clinical diagnosis, medication, previous TB, blood cell count, tuberculin skin test, and interferon-gamma (IFN-γ) level measured by IGRA was collected. Results Of the 66 patients, the initial IGRA was positive in 24.2%, negative in 65.2%, and indeterminate in 10.6%. Forty-six patients (69.7%) showed consistent IGRA results during follow-up, and 13 patients (19.7%) had consistently positive results. IGRA conversion rate was 12.1% (8/66) and reversion rate was 4.5% (3/66). Conversion of IGRA results was only observed in ankylosing spondylitis patients, and the median interval between the two tests in patients with conversion was 8.5 months. The mean IFN-γ level in the group of patients with consistently positive IGRA results was higher than that in the group with inconsistently positive results, although this trend was not statistically significant (P=0.293). Indeterminate results were observed most frequently in patients with systemic lupus erythematosus. Conclusions In patients receiving immunosuppressive agents, both IGRA conversions and reversions were observed. Serial IGRA testing may not be needed in patients with a positive initial IGRA result showing high IFN-γ levels, because of high consistency in the test results. PMID:22016681

  9. Expression of B7 (CD80) and CD40 antigens and the CD40 ligand in Hodgkin's disease is independent of latent Epstein—Barr virus infection

    PubMed Central

    Murray, P G; Oates, J; Reynolds, G M; Crocker, J; Young, L S

    1995-01-01

    Aim—To examine the expression of CD40 and B7 (CD80) antigens and the CD40 ligand in Hodgkin's disease. Methods—Antigen and ligand expression was studied in 17 cases of Hodgkin's disease using immunohistochemistry. The study included 11 cases of Hodgkin's disease in which latent Epstein-Barr virus (EBV) infection could be demonstrated within tumour cells by in situ hybridisation for the EBV encoded early RNAs (EBERs). Results—In all cases, irrespective of EBV status, Reed-Sternberg cells and their variants (HRS cells) showed strong expression of both B7 and CD40 antigens. CD40 ligand expression was not shown in HRS cells but was confined to a subset of small lymphocytes some of which were seen to be in intimate contact with HRS cells. Paraffin wax sections from a further 60 cases of Hodgkin's disease were examined for CD40 and EBER expression alone. The CD40 antigen was identified in HRS cells in all of these cases irrespective of EBER expression. Conclusions—As CD40 and B7 expression are features of professional antigen presenting cells, these results provide further evidence that HRS cells may have antigen presenting properties and that this may contribute to the characteristic recruitment and activation of non-malignant lymphocytes which is a feature of Hodgkin's disease. The ability of HRS cells to activate Th cells may in turn contribute to their own survival through the induction of the gp39/CD40 pathway. Images PMID:16695980

  10. Potential Role for Mycobacterium tuberculosis Specific IL-2 and IFN-γ Responses in Discriminating between Latent Infection and Active Disease after Long-Term Stimulation

    PubMed Central

    Sun, Qin; Wei, Wei; Sha, Wei

    2016-01-01

    Interferon gamma release assays (IGRAs) could accurately diagnose Mycobacterium tuberculosis (M.tuberculosis) infection. However, these assays do not discriminate between latent tuberculosis infection (LTBI) and active tuberculosis disease (ATB). Here, a total of 177 subjects, including 65 patients with ATB, 43 subjects with LTBI, and 69 TB-uninfected controls (CON group) were enrolled. The concentration of IFN-γ, IP-10, and IL-2 was determined in peripheral blood mononuclear cells (PBMCs) after short-term (24h) or long-term (72h) stimulation with TB antigens including ESAT-6/CFP-10 (EC) and purified protein derivative (PPD).EC-stimulated IL-2 and gamma interferon-inducible protein 10 (IP-10) release (24h and 72h) showed a good diagnostic performance in distinguishing between TB-infected and TB-uninfected individuals, but failed to discriminate between ATB and LTBI. After 72h of incubation, the release of IL-2 was higher in LTBI patients after stimulation with EC and PPD. The PPD-stimulated IL-2/IFN-γ ratio after 72h incubation had the diagnostic potential to discriminate between ATB and LTBI, with a sensitivity of 90.8% and a specificity of 97.7%. In addition, these new biomarkers, combined with T-SPOT test in a two-step strategy, were validated with high levels of accuracy in a prospective clinical-based cohort. Collectively, the PPD-stimulated IL-2/IFN-γ ratio after long-term incubation may be an alternative diagnostic biomarker in distinguishing between active TB patients and subjects with latent infection. PMID:28033330

  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. Latent autoimmune diabetes in adults: definition, prevalence, beta-cell function, and treatment.

    PubMed

    Stenström, Gunnar; Gottsäter, Anders; Bakhtadze, Ekaterine; Berger, Bo; Sundkvist, Göran

    2005-12-01

    Latent autoimmune diabetes in adults (LADA) is a disorder in which, despite the presence of islet antibodies at diagnosis of diabetes, the progression of autoimmune beta-cell failure is slow. LADA patients are therefore not insulin requiring, at least during the first 6 months after diagnosis of diabetes. Among patients with phenotypic type 2 diabetes, LADA occurs in 10% of individuals older than 35 years and in 25% below that age. Prospective studies of beta-cell function show that LADA patients with multiple islet antibodies develop beta-cell failure within 5 years, whereas those with only GAD antibodies (GADAs) or only islet cell antibodies (ICAs) mostly develop beta-cell failure after 5 years. Even though it may take up to 12 years until beta-cell failure occurs in some patients, impairments in the beta-cell response to intravenous glucose and glucagon can be detected at diagnosis of diabetes. Consequently, LADA is not a latent disease; therefore, autoimmune diabetes in adults with slowly progressive beta-cell failure might be a more adequate concept. In agreement with proved impaired beta-cell function at diagnosis of diabetes, insulin is the treatment of choice.

  13. CD4+ T-cell-independent mechanisms suppress reactivation of latent tuberculosis in a macaque model of HIV coinfection.

    PubMed

    Foreman, Taylor W; Mehra, Smriti; LoBato, Denae N; Malek, Adel; Alvarez, Xavier; Golden, Nadia A; Bucşan, Allison N; Didier, Peter J; Doyle-Meyers, Lara A; Russell-Lodrigue, Kasi E; Roy, Chad J; Blanchard, James; Kuroda, Marcelo J; Lackner, Andrew A; Chan, John; Khader, Shabaana A; Jacobs, William R; Kaushal, Deepak

    2016-09-20

    The synergy between Mycobacterium tuberculosis (Mtb) and HIV in coinfected patients has profoundly impacted global mortality because of tuberculosis (TB) and AIDS. HIV significantly increases rates of reactivation of latent TB infection (LTBI) to active disease, with the decline in CD4(+) T cells believed to be the major causality. In this study, nonhuman primates were coinfected with Mtb and simian immunodeficiency virus (SIV), recapitulating human coinfection. A majority of animals exhibited rapid reactivation of Mtb replication, progressing to disseminated TB and increased SIV-associated pathology. Although a severe loss of pulmonary CD4(+) T cells was observed in all coinfected macaques, a subpopulation of the animals was still able to prevent reactivation and maintain LTBI. Investigation of pulmonary immune responses and pathology in this cohort demonstrated that increased CD8(+) memory T-cell proliferation, higher granzyme B production, and expanded B-cell follicles correlated with protection from reactivation. Our findings reveal mechanisms that control SIV- and TB-associated pathology. These CD4-independent protective immune responses warrant further studies in HIV coinfected humans able to control their TB infection. Moreover, these findings will provide insight into natural immunity to Mtb and will guide development of novel vaccine strategies and immunotherapies.

  14. Predictive factors for latent tuberculosis infection among adolescents in a high-burden area in South Africa.

    PubMed

    Mahomed, H; Hawkridge, T; Verver, S; Geiter, L; Hatherill, M; Abrahams, D-A; Ehrlich, R; Hanekom, W A; Hussey, G D

    2011-03-01

    A high tuberculosis (TB) burden area in South Africa (notification rate for all TB cases 1400 per 100 000 population). To determine the prevalence of and predictive factors associated with latent TB infection in adolescents. Adolescents aged 12-18 years were recruited from high schools, clinical and demographic data were collected, and a tuberculin skin test (TST) and a QuantiFERON®-TB Gold In-Tube (QFT) assay performed. A total of 6363 (58.2%) of 10 942 adolescents at the schools were enrolled. After exclusions, of 5244 participants, 55.2% (95%CI 53.8-56.5) had TST ≥ 5 mm, while 50.9% (49.5-52.2) were QFT-positive. On multivariate analysis, Black/mixed race racial groups, male sex, older age, household TB contact, low income and low education level were predictive factors for both TST- and QFT-positive results. About half of the adolescents were found to be latently infected with TB in a high TB burden area with demographic and poverty-related socio-economic factors predicting the risk of TB infection. Adolescents from deprived communities should be considered an important target group for educational interventions by TB control programmes in high-burden settings.

  15. Extended culture enhances sensitivity of a gamma interferon assay for latent Mycobacterium tuberculosis infection.

    PubMed

    Cehovin, Ana; Cliff, Jacqueline M; Hill, Philip C; Brookes, Roger H; Dockrell, Hazel M

    2007-06-01

    To test the hypothesis that prolonged culture would enhance the sensitivity of latent tuberculosis detection by a gamma interferon release assay, blood samples from 33 household contacts of Gambian tuberculosis patients were stimulated with Mycobacterium tuberculosis-specific antigens. After 24 h of culture, 66% were positive, compared to 93% after 6 days of culture.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  17. The p19 protein of Grapevine Algerian latent virus is a determinant of systemic infection of Chenopodium quinoa.

    PubMed

    Kim, Semin; Cho, Won Kyong; Lee, Hyeok-Geun; Park, Sang-Ho; Sohn, Seong-Han; Kim, Kook-Hyung

    2012-04-01

    A previous study showed that both Grapevine Algerian latent virus (GALV) and Tomato bushy stunt virus (TBSV) systemically infect Nicotiana benthamiana, but GALV causes systemic infection whereas TBSV causes only local lesions in Chenopodium quinoa (C. quinoa). We recently isolated GALV strain Naju (GALV-N) from Limonium sinense and TBSV strain Sacheon (TBSV-S) from tomato. Both viruses belong to the genus Tombusvirus and have a similar genome organization. To identify determinants of systemic infection of GALV-N in C. quinoa in the current study, we generated infectious clones and capsid protein (CP)-deletion clones for the two viruses and confirmed that CP of GALV-N is required for systemic infection of C. quinoa due to its primary structural role in virus assembly. Through the use of chimeras, we identified a viral factor in addition to CP that contributes to systemic infection by GALV-N. Inactivation of the p19 demonstrated that host-specific activities of p19 are necessary for efficient systemic infection of C. quinoa by GALV-N. Our study is the first report to determine the viral factors required for systemic infection of GALV in C. quinoa.

  18. 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

  19. Final Report: Latent Expression of Genetic Damage in Human Lung Cells

    SciTech Connect

    Cornforth, Michael N.

    1999-02-28

    This project was aimed at furthering understanding of the latent effects of ionizing radiation. The underlying premise was that such latent (i.e., delayed) effects stemmed from radiation-induced genetic instability. As model system to investigate certain aspects of genomic instability, they proposed to look at chromosomal instability involving quasi-targeted radiation-induced breakpoints in the vicinity of the HPRT gene in EJ30 human epithelial cells. Using whole chromosome painting of the X chromosome, the authors were able to show that about 15% of randomly selected 6-thioguanine resistant (6TG{prime}) mutants involved translocations in the terminal portion of Xq. Subsequent analysis, using human genomic YAC probes confirmed that all the translocations were either within (or near Xq26.1), the cytogenetic location of HPRT, whereas none were found elsewhere involving the X chromosome.

  20. A movement protein and three capsid proteins are all necessary for the cell-to-cell movement of apple latent spherical cheravirus.

    PubMed

    Yoshikawa, N; Okada, K; Asamuma, K; Watanabe, K; Igarasi, A; Li, C; Isogai, M

    2006-05-01

    Immunoblot analysis of apple latent spherical cheravirus (ALSV)-infected leaves using a polyclonal antibody against the 21 C-terminal amino acids of a 53 K/42 K movement protein (MP) showed that a protein with an Mr of 42 kDa (42KP) is the dominant form found in vivo, which could indicate that the second AUG is used as an initiation codon of a ORF in RNA2. Co-expression of GFP with 42KP in tobacco epidermal cells showed that 42KP is able to facilitate cell-to-cell trafficking of GFP that is expressed in the same cells. The analysis of deletion mutants on each of MP, Vp24, Vp20, or Vp25 using an ALSV vector that stably expresses GFP indicated that an MP and three capsid proteins are all indispensable for the cell-to-cell movement of the virus. In ultrathin sections of infected leaves, a file of virus-like particles passing through the plasmodesmata connecting neighboring cells and tubular structures containing virus-like particles extending into the cytoplasm were observed. These results show that ALSV moves from cell to cell as virus particles.

  1. Kaposi's sarcoma-associated herpesvirus infection of blood endothelial cells induces lymphatic differentiation.

    PubMed

    Carroll, Patrick A; Brazeau, Elizabeth; Lagunoff, Michael

    2004-10-10

    Kaposi's sarcoma-associated herpesvirus (KSHV) is necessary for KS, a highly vascularized tumor predominated by endothelial-derived spindle cells that express markers of lymphatic endothelium. Following KSHV infection of TIME cells, an immortalized human dermal microvascular endothelial cell (DMVEC) line, expression of many genes specific to lymphatic endothelium, including VEGFR3, podoplanin, LYVE-1, and Prox-1, is significantly increased. Increases in VEGFR3 and podoplanin protein are also demonstrated following latent infection. Examination of cytokine secretion showed that KSHV infection significantly induces hIL-6 while strongly inhibiting secretion of IL-8, a gene product that is decreased by differentiation of blood to lymphatic endothelial cells. These studies support the hypotheses that latent KSHV infection of blood endothelial cells drives their differentiation to lymphatic endothelial cells.

  2. Influence of diabetes mellitus and risk factors in activating latent tuberculosis infection: a case for targeted screening in malaysia.

    PubMed

    Swarna Nantha, Y

    2012-10-01

    A review of the epidemiology of tuberculosis, its contributing risk factors (excluding HIV) and the role of screening latent tuberculosis infection in Malaysia was done. Despite the global and domestic decrease in prevalence rates of tuberculosis in the past decade, there is an alarming increase in the trend of non communicable diseases in the country. High prevalence rates of major risk factors leading to reactivation of tuberculosis were seen within the population, with diabetes mellitus being in the forefront. The rising numbers in the ageing population of Malaysia poses a further threat of re-emergence of tuberculosis in the years to come. Economically, screening of diabetic patients with comorbidities for latent tuberculosis infection (LTBI) using two major techniques, namely tuberculin sensitivity (TST) and Interferon gamma release assay tests (IGRA) could be a viable option. The role of future research in the detection of LTBI in the Malaysian setting might be necessary to gauge the disease reservoir before implementing prophylactic measures for high risk groups involved.

  3. 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.

  4. The Ozobranchus leech is a candidate mechanical vector for the fibropapilloma-associated turtle herpesvirus found latently infecting skin tumors on Hawaiian green turtles (Chelonia mydas)

    USGS Publications Warehouse

    Greenblatt, R.J.; Work, Thierry 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.

  5. Prevalence and associated risk factors of latent tuberculosis infection among undergraduate and postgraduate dental students: A retrospective study.

    PubMed

    Lamberti, Monica; Muoio, Maria Rosaria; Westermann, Claudia; Nienhaus, Albert; Arnese, Antonio; Ribeiro Sobrinho, Antônio Paulino; Di Giuseppe, Gabriella; Garzillo, Elpidio Maria; Crispino, Vincenzo; Coppola, Nicola; De Rosa, Alfredo

    2017-03-04

    To estimate the prevalence of latent tuberculosis (TB) infection (LTBI) in Italian dental students exposed to the same occupational risks as dental health care personnel and to evaluate potential risk factors, a cross-sectional study was conducted on undergraduate and postgraduate students. After clinical evaluation, students were given a tuberculin skin test; in those found positive, an interferon-γ release assay (IGRA) was conducted. Of the 281 students enrolled, 10 were only TST positive; 8 were TST or/and IGRA positive. We found that participants testing positive at TST and/or IGRA, a group in which the risk of false LTBI positives is minimal, were older and had been studying longer. Although the prevalence of LTBI among dental students in our study was low, a risk of acquiring a work-related infection exists even in a country with a low incidence of TB. Thus, dental students should be screened to catch LTBI early on.

  6. [Neonatal screening for congenital Chagas infection: application of latent class analysis for diagnostic test evaluation].

    PubMed

    Andrade, André Queiroz de; Gontijo, Eliane Dias

    2008-01-01

    The present study had the aim of evaluating conventional serum tests that are used in neonatal screening for Chagas disease, with a discussion on the statistical methods available. A random sample among 23,308 newborns who were screened for congenital Chagas disease was studied using the following three tests: enzyme immunoassay, indirect immunofluorescence and indirect hemagglutination. The data were analyzed by different statistical methodologies: latent class analysis, Kappa test and relative sensitivity analysis. Using latent class analysis, enzyme immunoassay had the highest sensitivity (48.6%), followed by indirect immunofluorescence (39.8%) and indirect hemagglutination (23.2%). The kappa value was 0.496. The ratio between the sensitivities of enzyme immunoassays and indirect immunofluorescence tests was 92% [0.74;1.13]. Latent class analysis was not found to be adequate for sensitivity and specificity determination, but it provided important data about the equivalence of the tests, corroborated by relative sensitivity analysis. The results showed that enzyme immunoassaying of dry blood samples can be used as safely as the indirect immunofluorescence test.

  7. 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

  8. 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

  9. Construction of a System for the Strawberry Nursery Production towards Elimination of Latent Infection of Anthracnose Fungi by a Combination of PCR and Microtube Hybridization.

    PubMed

    Furuta, Kazuyoshi; Nagashima, Saki; Inukai, Tsuyoshi; Masuta, Chikara

    2017-02-01

    One of the major problems in strawberry production is difficulty in diagnosis of anthracnose caused by Colletotrichum acutatum or Glomerella cingulata in latent infection stage. We here developed a diagnostic tool for the latent infection consisting of initial culturing of fungi, DNA extraction, synthesis of PCR-amplified probes and microtube hybridization (MTH) using a macroarray. The initial culturing step is convenient to lure the fungi out of the plant tissues, and to extract PCR-inhibitor-free DNA directly from fungal hyphae. For specific detection of the fungi, PCR primers were designed to amplify the fungal MAT1-2 gene. The subsequent MTH step using the PCR products as probes can replace the laborious electrophoresis step providing us sequence information and high-throughput screening. Using this method, we have conducted a survey for a few thousands nursery plants every year for three consecutive years, and finally succeeded in eliminating latent infection in the third year of challenge.

  10. Construction of a System for the Strawberry Nursery Production towards Elimination of Latent Infection of Anthracnose Fungi by a Combination of PCR and Microtube Hybridization

    PubMed Central

    Furuta, Kazuyoshi; Nagashima, Saki; Inukai, Tsuyoshi; Masuta, Chikara

    2017-01-01

    One of the major problems in strawberry production is difficulty in diagnosis of anthracnose caused by Colletotrichum acutatum or Glomerella cingulata in latent infection stage. We here developed a diagnostic tool for the latent infection consisting of initial culturing of fungi, DNA extraction, synthesis of PCR-amplified probes and microtube hybridization (MTH) using a macroarray. The initial culturing step is convenient to lure the fungi out of the plant tissues, and to extract PCR-inhibitor-free DNA directly from fungal hyphae. For specific detection of the fungi, PCR primers were designed to amplify the fungal MAT1-2 gene. The subsequent MTH step using the PCR products as probes can replace the laborious electrophoresis step providing us sequence information and high-throughput screening. Using this method, we have conducted a survey for a few thousands nursery plants every year for three consecutive years, and finally succeeded in eliminating latent infection in the third year of challenge. PMID:28167891

  11. Mechanisms Underlying T Cell Immunosenescence: Aging and Cytomegalovirus Infection

    PubMed Central

    Tu, Wenjuan; Rao, Sudha

    2016-01-01

    The ability of the human immune system to protect against infectious disease declines with age and efficacy of vaccination reduces significantly in the elderly. Aging of the immune system, also termed as immunosenescence, involves many changes in human T cell immunity that is characterized by a loss in naïve T cell population and an increase in highly differentiated CD28- memory T cell subset. There is extensive data showing that latent persistent human cytomegalovirus (HCMV) infection is also associated with age-related immune dysfunction in the T cells, which might enhance immunosenescence. Understanding the molecular mechanisms underlying age-related and HCMV-related immunosenescence is critical for the development of effective age-targeted vaccines and immunotherapies. In this review, we will address the role of both aging and HCMV infection that contribute to the T cell senescence and discuss the potential molecular mechanisms in aged T cells. PMID:28082969

  12. Identification and sequencing of a novel rodent gammaherpesvirus that establishes acute and latent infection in laboratory mice.

    PubMed

    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

    2011-03-01

    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.

  13. 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.

  14. Epstein-Barr Virus Downregulates MicroRNA 203 through the Oncoprotein Latent Membrane Protein 1: a Contribution to Increased Tumor Incidence in Epithelial Cells

    PubMed Central

    Yu, Haibo; Zuo, Lielian; Yan, Qijia; Yu, Zhengyuan; Li, Xiayu; Huang, Jin; Zhao, Lian; Tang, Hailin; Luo, Zhaohui; Liao, Qianjin; Zeng, Zhaoyang; Zhang, Junyi

    2012-01-01

    The Epstein-Barr virus (EBV) is highly associated with nasopharyngeal carcinoma (NPC), and it regulates some microRNAs (miRNAs) that are involved in the development of cancer. The role of EBV in the deregulation of cellular miRNAs and how this affects the progression of NPC remain to be investigated. An analysis of the miRNA profile in an EBV-infected cell line revealed that miRNA 203 (miR-203) was downregulated. miR-203 is expressed specifically in epithelial cells. This downregulation of miR-203 was further verified and functionally analyzed. miR-203 was downregulated substantially in epithelial cells and NPC tissues that were latently infected with EBV. Downregulation of miR-203 also occurred during the early stage of EBV infection. Furthermore, the viral oncoprotein, latent membrane protein 1 (LMP1), was responsible for downregulation of miR-203. Removal of the latent EBV genome or suppression of LMP1 resulted in restoration of miR-203 expression. EBV-LMP1 mediated the downregulation of miR-203 at the primary transcript level. E2F3 and CCNG1 were identified as target genes of miR-203. Ectopic expression of miR-203 inhibited EBV-induced S-phase entry and transformation in vivo. Overexpression of the targets overcame the effects of miR-203 mimics on the cell cycle, and the expression of target genes in tumor models was inhibited by miR-203. Inhibitors of Jun N-terminal protein kinase (JNK) and NF-κB blocked miR-203 downregulation. These results imply that EBV promotes malignancy by downregulating cellular miR-203, which contributes to the etiology of NPC. PMID:22205737

  15. Defective T-cell control of Epstein–Barr virus infection in multiple sclerosis

    PubMed Central

    Pender, Michael P; Csurhes, Peter A; Burrows, Jacqueline M; Burrows, Scott R

    2017-01-01

    Mounting evidence indicates that infection with Epstein–Barr virus (EBV) has a major role in the pathogenesis of multiple sclerosis (MS). Defective elimination of EBV-infected B cells by CD8+ T cells might cause MS by allowing EBV-infected autoreactive B cells to accumulate in the brain. Here we undertake a comprehensive analysis of the T-cell response to EBV in MS, using flow cytometry and intracellular IFN-γ staining to measure T-cell responses to EBV-infected autologous lymphoblastoid cell lines and pools of human leukocyte antigen (HLA)-class-I-restricted peptides from EBV lytic or latent proteins and cytomegalovirus (CMV), in 95 patients and 56 EBV-seropositive healthy subjects. In 20 HLA-A2+ healthy subjects and 20 HLA-A2+ patients we also analysed CD8+ T cells specific for individual peptides, measured by binding to HLA-peptide complexes and production of IFN-γ, TNF-α and IL-2. We found a decreased CD8+ T-cell response to EBV lytic, but not CMV lytic, antigens at the onset of MS and at all subsequent disease stages. CD8+ T cells directed against EBV latent antigens were increased but had reduced cytokine polyfunctionality indicating T-cell exhaustion. During attacks the EBV-specific CD4+ and CD8+ T-cell populations expanded, with increased functionality of latent-specific CD8+ T cells. With increasing disease duration, EBV-specific CD4+ and CD8+ T cells progressively declined, consistent with T-cell exhaustion. The anti-EBNA1 IgG titre correlated inversely with the EBV-specific CD8+ T-cell frequency. We postulate that defective CD8+ T-cell control of EBV reactivation leads to an expanded population of latently infected cells, including autoreactive B cells. PMID:28197337

  16. Predictors of low prevalence of latent tuberculosis infection among Egyptian health care workers at intensive care and bronchoscopy units

    PubMed Central

    Hefzy, Enas Mamdouh; Wegdan, Ahmed Ashraf; Elhefny, Radwa Ahmed; Nasser, Samar Hassan

    2016-01-01

    Aim: Latent tuberculosis infections (LTBI) contain a significant reservoir for future epidemics. Screening of health care workers (HCWs) in a high-risk tuberculosis (TB) environment is an important strategy in TB control. The study aimed to assess the prevalence of LTBI among high risk Egyptian HCWs and to assess infection associated risk factors. Methods: Fifty-two HCWs who work at intensive care unit (ICU), bronchoscopy unit, and chest diseases department were tested for LTBI using both tuberculin skin test (TST) and Quantiferon TB Gold in-tube test (QFT). Risk factors for infection, knowledge of HCWs towards different aspects of TB infection and agreement between TST and QFT were also evaluated. Results: Prevalence of LTBI in this study was 13.5% by QFT and TST. It was 13.6% by TST alone and 10.3% by QFT alone. There was good concordance between both tests (Kappa=0.713). There was a statistically significant association between prevalence of LTBI and age of staff ≥30 yr (p=0.002), period of working experience (p=0.006) and working at the Bronchoscopy Unit (p=0.001). The total knowledge of HCWs towards different aspects of TB infection was generally good. Conclusion: Although the participants in the current study were among high risk HCWs, the prevalence of LTBI was low. Bacille Calmette-Guerin (BCG) vaccination, young age, short employment duration, good knowledge and a good infection control were the predictors of low risk of contracting TB at our hospitals. The risk of TB infection in resource-limited countries can be reduced with simple continuous educational and administrative infection control programmes. PMID:27777875

  17. Transient Oral Human Cytomegalovirus Infections Indicate Inefficient Viral Spread from Very Few Initially Infected Cells.

    PubMed

    Mayer, Bryan T; Krantz, Elizabeth M; Swan, David; Ferrenberg, James; Simmons, Karen; Selke, Stacy; Huang, Meei-Li; Casper, Corey; Corey, Lawrence; Wald, Anna; Schiffer, Joshua T; Gantt, Soren

    2017-06-15

    Cytomegalovirus (CMV) is acquired by the oral route in children, and primary infection is associated with abundant mucosal replication, as well as the establishment of latency in myeloid cells that results in lifelong infection. The efficiency of primary CMV infection in humans following oral exposure, however, is unknown. We consistently detected self-limited, low-level oral CMV shedding events, which we termed transient CMV infections, in a prospective birth cohort of 30 highly exposed CMV-uninfected infants. We estimated the likelihood of transient oral CMV infections by comparing their observed frequency to that of established primary infections, characterized by persistent high-level shedding, viremia, and seroconversion. We developed mathematical models of viral dynamics upon initial oral CMV infection and validated them using clinical shedding data. Transient infections comprised 76 to 88% of oral CMV shedding events. For this high percentage of transient infections to occur, we identified two mathematical prerequisites: a very small number of initially infected oral cells (1 to 4) and low viral infectivity (<1.5 new cells infected/cell). These observations indicate that oral CMV infection in infants typically begins with a single virus that spreads inefficiently to neighboring cells. Thus, although the incidence of CMV infection is high during infancy, our data provide a mechanistic framework to explain why multiple CMV exposures are typically required before infection is successfully established. These findings imply that a sufficiently primed immune response could prevent CMV from establishing latent infection in humans and support the achievability of a prophylactic CMV vaccine.IMPORTANCE CMV infects the majority of the world's population and is a major cause of birth defects. Developing a vaccine to prevent CMV infection would be extremely valuable but would be facilitated by a better understanding of how natural human CMV infection is acquired. We

  18. The multistage vaccine H56 boosts the effects of BCG to protect cynomolgus macaques against active tuberculosis and reactivation of latent Mycobacterium tuberculosis infection

    PubMed Central

    Lin, Philana Ling; Dietrich, Jes; Tan, Esterlina; Abalos, Rodolfo M.; Burgos, Jasmin; Bigbee, Carolyn; Bigbee, Matthew; Milk, Leslie; Gideon, Hannah P.; Rodgers, Mark; Cochran, Catherine; Guinn, Kristi M.; Sherman, David R.; Klein, Edwin; Janssen, Christopher; Flynn, JoAnne L.; Andersen, Peter

    2011-01-01

    It is estimated that one-third of the world’s population is infected with Mycobacterium tuberculosis. Infection typically remains latent, but it can reactivate to cause clinical disease. The only vaccine, Mycobacterium bovis bacillus Calmette-Guérin (BCG), is largely ineffective, and ways to enhance its efficacy are being developed. Of note, the candidate booster vaccines currently under clinical development have been designed to improve BCG efficacy but not prevent reactivation of latent infection. Here, we demonstrate that administering a multistage vaccine that we term H56 in the adjuvant IC31 as a boost to vaccination with BCG delays and reduces clinical disease in cynomolgus macaques challenged with M. tuberculosis and prevents reactivation of latent infection. H56 contains Ag85B and ESAT-6, which are two of the M. tuberculosis antigens secreted in the acute phase of infection, and the nutrient stress–induced antigen Rv2660c. Boosting with H56/IC31 resulted in efficient containment of M. tuberculosis infection and reduced rates of clinical disease, as measured by clinical parameters, inflammatory markers, and improved survival of the animals compared with BCG alone. Boosted animals showed reduced pulmonary pathology and extrapulmonary dissemination, and protection correlated with a strong recall response against ESAT-6 and Rv2660c. Importantly, BCG/H56-vaccinated monkeys did not reactivate latent infection after treatment with anti-TNF antibody. Our results indicate that H56/IC31 boosting is able to control late-stage infection with M. tuberculosis and contain latent tuberculosis, providing a rationale for the clinical development of H56. PMID:22133873

  19. The multistage vaccine H56 boosts the effects of BCG to protect cynomolgus macaques against active tuberculosis and reactivation of latent Mycobacterium tuberculosis infection.

    PubMed

    Lin, Philana Ling; Dietrich, Jes; Tan, Esterlina; Abalos, Rodolfo M; Burgos, Jasmin; Bigbee, Carolyn; Bigbee, Matthew; Milk, Leslie; Gideon, Hannah P; Rodgers, Mark; Cochran, Catherine; Guinn, Kristi M; Sherman, David R; Klein, Edwin; Janssen, Christopher; Flynn, JoAnne L; Andersen, Peter

    2012-01-01

    It is estimated that one-third of the world's population is infected with Mycobacterium tuberculosis. Infection typically remains latent, but it can reactivate to cause clinical disease. The only vaccine, Mycobacterium bovis bacillus Calmette-Guérin (BCG), is largely ineffective, and ways to enhance its efficacy are being developed. Of note, the candidate booster vaccines currently under clinical development have been designed to improve BCG efficacy but not prevent reactivation of latent infection. Here, we demonstrate that administering a multistage vaccine that we term H56 in the adjuvant IC31 as a boost to vaccination with BCG delays and reduces clinical disease in cynomolgus macaques challenged with M. tuberculosis and prevents reactivation of latent infection. H56 contains Ag85B and ESAT-6, which are two of the M. tuberculosis antigens secreted in the acute phase of infection, and the nutrient stress-induced antigen Rv2660c. Boosting with H56/IC31 resulted in efficient containment of M. tuberculosis infection and reduced rates of clinical disease, as measured by clinical parameters, inflammatory markers, and improved survival of the animals compared with BCG alone. Boosted animals showed reduced pulmonary pathology and extrapulmonary dissemination, and protection correlated with a strong recall response against ESAT-6 and Rv2660c. Importantly, BCG/H56-vaccinated monkeys did not reactivate latent infection after treatment with anti-TNF antibody. Our results indicate that H56/IC31 boosting is able to control late-stage infection with M. tuberculosis and contain latent tuberculosis, providing a rationale for the clinical development of H56.

  20. Euphorbia Kansui Reactivates Latent HIV

    PubMed Central

    Cary, Daniele C.; Fujinaga, Koh; Peterlin, B. Matija

    2016-01-01

    While highly active anti-retroviral therapy has greatly improved the lives of HIV infected individuals, these treatments are unable to eradicate the virus. Current approaches to reactivate the virus have been limited by toxicity, lack of an orally available therapy, and limited responses in primary CD4+ T cells and in clinical trials. The PKC agonist ingenol, purified from Euphorbia plants, is a potent T cell activator and reactivates latent HIV. Euphorbia kansui itself has been used for centuries in traditional Chinese medicine to treat ascites, fluid retention, and cancer. We demonstrate that an extract of this plant, Euphorbia kansui, is capable of recapitulating T cell activation induced by the purified ingenol. Indeed, Euphorbia kansui induced expression of the early T cell activation marker CD69 and P-TEFb in a dose-dependent manner. Furthermore, Euphorbia kansui reactivated latent HIV in a CD4+ T cell model of latency and in HIV+ HAART suppressed PBMC. When combined with the other latency reversing agents, the effective dose of Euphorbia kansui required to reactive HIV was reduced 10-fold and resulted in synergistic reactivation of latent HIV. We conclude that Euphorbia Euphorbia kansui reactivates latent HIV and activates CD4+ T cells. When used in combination with a latency reversing agent, the effective dose of Euphorbia kansui is reduced; which suggests its application as a combination strategy to reactivate latent HIV while limiting the toxicity due to global T cell activation. As a natural product, which has been used in traditional medicine for thousands of years, Euphorbia kansui is attractive as a potential treatment strategy, particularly in resource poor countries with limited treatment options. Further clinical testing will be required to determine its safety with current anti-retroviral therapies. PMID:27977742

  1. Detection of immediate early protein ICP27/IE63 and thymidine kinase in the course of reactivation of latent herpes simplex virus 1 infection.

    PubMed

    Durmanová, V; Rajcáni, J

    2003-01-01

    We followed the kinetics of reactivation of latent Herpes simplex virus 1 (HSV-1) infection established in rabbits by corneal route. The corresponding trigeminal ganglia (TG) were cultured and the culture medium was examined at daily intervals for release of infectious virus. Sections from the cultured TG fragments were stained with antisera against non-structural proteins such as the immediate early (IE) protein ICP27 and the early (E) proteins thymidine kinase (TK), the large subunit of ribonucleotide reductase (RR1), the ori-binding protein OBP and with a human serum obtained from volunteers immunized with an experimental subunit HSV-1 envelope (env) vaccine containing late structural proteins gB1, gC1, gD1 and gG1 (env antiserum). By indirect immunofluorescence (IF) test, ICP27 was detected in a few neurons from day 1 post explantation (p.e.), while TK was observed in neurons from day 2 p.e. Fluorescence with the human env antiserum was seen at day 3 p.e. The RR1 and OBP antisera stained productively infected Vero cells from 3 and 4 hrs post inoculation (p.i.), respectively. However, these sera showed no IF in cultured ganglion fragments at any interval examined. Our results showed the same cascade of HSV-1 IE and E protein expression during productive infection and reactivation in vitro.

  2. NKG2A-Expressing Natural Killer Cells Dominate the Response to Autologous Lymphoblastoid Cells Infected with Epstein–Barr Virus

    PubMed Central

    Hatton, Olivia; Strauss-Albee, Dara Marie; Zhao, Nancy Q.; Haggadone, Mikel D.; Pelpola, Judith Shanika; Krams, Sheri M.; Martinez, Olivia M.; Blish, Catherine A.

    2016-01-01

    Epstein–Barr virus (EBV) is a human γ-herpesvirus that establishes latency and lifelong infection in host B cells while achieving a balance with the host immune response. When the immune system is perturbed through immunosuppression or immunodeficiency, however, these latently infected B cells can give rise to aggressive B cell lymphomas. Natural killer (NK) cells are regarded as critical in the early immune response to viral infection, but their role in controlling expansion of infected B cells is not understood. Here, we report that NK cells from healthy human donors display increased killing of autologous B lymphoblastoid cell lines (LCLs) harboring latent EBV compared to primary B cells. Coculture of NK cells with autologous EBV+ LCL identifies an NK cell population that produces IFNγ and mobilizes the cytotoxic granule protein CD107a. Multi-parameter flow cytometry and Boolean analysis reveal that these functional cells are enriched for expression of the NK cell receptor NKG2A. Further, NKG2A+ NK cells more efficiently lyse autologous LCL than do NKG2A− NK cells. More specifically, NKG2A+2B4+CD16−CD57−NKG2C−NKG2D+ cells constitute the predominant NK cell population that responds to latently infected autologous EBV+ B cells. Thus, a subset of NK cells is enhanced for the ability to recognize and eliminate autologous, EBV-infected transformed cells, laying the groundwork for harnessing this subset for therapeutic use in EBV+ malignancies. PMID:28018364

  3. Detection of anti-HspX antibodies and HspX protein in patient sera for the identification of recent latent infection by Mycobacterium tuberculosis.

    PubMed

    Castro-Garza, Jorge; García-Jacobo, Paola; Rivera-Morales, Lydia G; Quinn, Frederick D; Barber, James; Karls, Russell; Haas, Debra; Helms, Shelly; Gupta, Tuhina; Blumberg, Henry; Tapia, Jane; Luna-Cruz, Itza; Rendon, Adrián; Vargas-Villarreal, Javier; Vera-Cabrera, Lucio; Rodríguez-Padilla, Cristina

    2017-01-01

    Mycobacterium tuberculosis is a pathogen causing tuberculosis (TB) a spectrum of disease including acute and asymptomatic latent stages. Identifying and treating latently-infected patients constitutes one of the most important impediments to TB control efforts. Those individuals can remain undiagnosed for decades serving as potential reservoirs for disease reactivation. Tests for the accurate diagnosis of latent infection currently are unavailable. HspX protein (α-crystallin), encoded by Rv2031c gene, is produced in vitro by M. tuberculosis during stationary growth phase and hypoxic or acidic culture conditions. In this study, using standard, and Luminex xMAP® bead capture ELISA, respectively, we report on detection of anti-HspX IgG and IgM antibodies and HspX protein in sera from acute and latent TB patients. For the antibody screen, levels of IgG and IgM antibodies were similar between non-infected and active TB patients; however, individuals classified into the group with latent TB showed higher values of anti-HspX IgM (p = 0.003) compared to active TB patients. Using the bead capture antigen detection assay, HspX protein was detected in sera from 56.5% of putative latent cases (p< 0.050) compared to the background median with an average of 9,900 pg/ml and a range of 1,000 to 36,000 pg/ml. Thus, presence of anti-HspX IgM antibodies and HspX protein in sera may be markers of latent TB.

  4. Detection of anti-HspX antibodies and HspX protein in patient sera for the identification of recent latent infection by Mycobacterium tuberculosis

    PubMed Central

    García-Jacobo, Paola; Rivera-Morales, Lydia G.; Barber, James; Karls, Russell; Haas, Debra; Helms, Shelly; Gupta, Tuhina; Blumberg, Henry; Tapia, Jane; Luna-Cruz, Itza; Rendon, Adrián; Vargas-Villarreal, Javier; Vera-Cabrera, Lucio; Rodríguez-Padilla, Cristina

    2017-01-01

    Mycobacterium tuberculosis is a pathogen causing tuberculosis (TB) a spectrum of disease including acute and asymptomatic latent stages. Identifying and treating latently-infected patients constitutes one of the most important impediments to TB control efforts. Those individuals can remain undiagnosed for decades serving as potential reservoirs for disease reactivation. Tests for the accurate diagnosis of latent infection currently are unavailable. HspX protein (α-crystallin), encoded by Rv2031c gene, is produced in vitro by M. tuberculosis during stationary growth phase and hypoxic or acidic culture conditions. In this study, using standard, and Luminex xMAP® bead capture ELISA, respectively, we report on detection of anti-HspX IgG and IgM antibodies and HspX protein in sera from acute and latent TB patients. For the antibody screen, levels of IgG and IgM antibodies were similar between non-infected and active TB patients; however, individuals classified into the group with latent TB showed higher values of anti-HspX IgM (p = 0.003) compared to active TB patients. Using the bead capture antigen detection assay, HspX protein was detected in sera from 56.5% of putative latent cases (p< 0.050) compared to the background median with an average of 9,900 pg/ml and a range of 1,000 to 36,000 pg/ml. Thus, presence of anti-HspX IgM antibodies and HspX protein in sera may be markers of latent TB. PMID:28813434

  5. Sustained CD8+ T cell memory inflation after infection with a single-cycle cytomegalovirus.

    PubMed

    Snyder, Christopher M; Cho, Kathy S; Bonnett, Elizabeth L; Allan, Jane E; Hill, Ann B

    2011-10-01

    Cytomegalovirus (CMV) is a β-herpesvirus that establishes a lifelong latent or persistent infection. A hallmark of chronic CMV infection is the lifelong persistence of large numbers of virus-specific CD8+ effector/effector memory T cells, a phenomenon called "memory inflation". How the virus continuously stimulates these T cells without being eradicated remains an enigma. The prevailing view is that CMV establishes a low grade "smoldering" infection characterized by tiny bursts of productive infection which are rapidly extinguished, leaving no detectable virus but replenishing the latent pool and leaving the immune system in a highly charged state. However, since abortive reactivation with limited viral gene expression is known to occur commonly, we investigated the necessity for virus reproduction in maintaining the inflationary T cell pool. We inhibited viral replication or spread in vivo using two different mutants of murine CMV (MCMV). First, famcyclovir blocked the replication of MCMV encoding the HSV Thymidine Kinase gene, but had no impact on the CD8+ T cell memory inflation once the infection was established. Second, MCMV that lacks the essential glycoprotein L, and thus is completely unable to spread from cell to cell, also drove memory inflation if the virus was administered systemically. Our data suggest that CMV which cannot spread from the cells it initially infects can repeatedly generate viral antigens to drive memory inflation without suffering eradication of the latent genome pool.

  6. Early events associated with infection of Epstein-Barr virus infection of primary B-cells.

    PubMed

    Halder, Sabyasachi; Murakami, Masanao; Verma, Subhash C; Kumar, Pankaj; Yi, Fuming; Robertson, Erle S

    2009-09-28

    Epstein Barr virus (EBV) is closely associated with the development of a vast number of human cancers. To develop a system for monitoring early cellular and viral events associated with EBV infection a self-recombining BAC containing 172-kb of the Epstein Barr virus genome BAC-EBV designated as MD1 BAC (Chen et al., 2005, J.Virology) was used to introduce an expression cassette of green fluorescent protein (GFP) by homologous recombination, and the resultant BAC clone, BAC-GFP-EBV was transfected into the HEK 293T epithelial cell line. The resulting recombinant GFP EBV was induced to produce progeny virus by chemical inducer from the stable HEK 293T BAC GFP EBV cell line and the virus was used to immortalize human primary B-cell as monitored by green fluorescence and outgrowth of the primary B cells. The infection, B-cell activation and cell proliferation due to GFP EBV was monitored by the expression of the B-cell surface antigens CD5, CD10, CD19, CD23, CD39, CD40 , CD44 and the intercellular proliferation marker Ki-67 using Flow cytometry. The results show a dramatic increase in Ki-67 which continues to increase by 6-7 days post-infection. Likewise, CD40 signals showed a gradual increase, whereas CD23 signals were increased by 6-12 hours, maximally by 3 days and then decreased. Monitoring the viral gene expression pattern showed an early burst of lytic gene expression. This up-regulation of lytic gene expression prior to latent genes during early infection strongly suggests that EBV infects primary B-cell with an initial burst of lytic gene expression and the resulting progeny virus is competent for infecting new primary B-cells. This process may be critical for establishment of latency prior to cellular transformation. The newly infected primary B-cells can be further analyzed for investigating B cell activation due to EBV infection.

  7. Alteration of CD44 expression in HIV type 1-infected T cell lines.

    PubMed

    Giordanengo, V; Limouse, M; Doglio, A; Lesimple, J; Lefebvre, J C

    1996-11-20

    CD44 is known to interfere in HIV replication and to participate in many physiological processes such as lymphocyte binding to high endothelial venules of lymphoid tissue, lymph nodes, and mucosal endothelium. The T cell lines MOLT-4 and CEM, and CEM subclones were infected with the HIV-1 LAI strain and monitored for the expression of CD44 during the course of chronic virus production until the infected cells were at the stage of latent infection. The levels of CD44 protein expression were quantified using cell surface immunostaining and biotinylation. The maturation of CD44 molecules was evaluated by metabolic sulforadiolabeling and CD44 mRNA was visualized by Northern blot analysis. We show a downmodulation of CD44 expression in infected T cell lines and subclones. This phenomenon was most evident at the stage of latent infection. Then, CD44 molecules were undetectable at both the protein and mRNA levels in latently infected CEM cells and CEM subclones. In addition, the 97-kDa standard CD44 isoform showed a shift upward, while detectable during the stage of chronic virus production. In latently infected MOLT-4 cells, the CD44 protein levels were dramatically decreased; CD44 mRNA was detected, but the sizes differed from the mRNA in uninfected cells. Since CD44 is known to regulate in part lymphocyte homing and HIV replication, the alterations that were observed in the expression of this molecule could interfere with the particular homing of HIV-infected cells and/or viral latency.

  8. Retroviral DNA--the silent winner: blood transfusion containing latent feline leukemia provirus causes infection and disease in naïve recipient cats.

    PubMed

    Nesina, Stefanie; Katrin Helfer-Hungerbuehler, A; Riond, Barbara; Boretti, Felicitas S; Willi, Barbara; Meli, Marina L; Grest, Paula; Hofmann-Lehmann, Regina

    2015-12-21

    The feline leukemia virus (FeLV) is a gamma-retrovirus of domestic cats that was discovered half a century ago. Cats that are infected with FeLV may develop a progressive infection resulting in persistent viremia, immunodeficiency, tumors, anemia and death. A significant number of cats mount a protective immune response that suppresses viremia; these cats develop a regressive infection characterized by the absence of viral replication and the presence of low levels of proviral DNA. The biological importance of these latter provirus carriers is largely unknown. Here, we demonstrate that ten cats that received a transfusion of blood from aviremic provirus carriers developed active FeLV infections, some with a progressive outcome and the development of fatal FeLV-associated disease. The infection outcome, disease spectrum and evolution into FeLV-C in one cat mirrored those of natural infection. Two cats developed persistent antigenemia; six cats were transiently antigenemic. Reactivation of infection occurred in some cats. One recipient developed non-regenerative anemia associated with FeLV-C, and four others developed a T-cell lymphoma, one with secondary lymphoblastic leukemia. Five of the ten recipient cats received provirus-positive aviremic blood, whereas the other five received provirus- and viral RNA-positive but aviremic blood. Notably, the cats that received blood containing only proviral DNA exhibited a later onset but graver outcome of FeLV infection than the cats that were transfused with blood containing proviral DNA and viral RNA. Leukocyte counts and cytokine analyses indicated that the immune system of the latter cats reacted quicker and more efficiently. Our results underline the biological and epidemiological relevance of FeLV provirus carriers and the risk of inadvertent FeLV transmission via blood transfusion and demonstrate the replication capacity of proviral DNA if uncontrolled by the immune system. Our results have implications not only for

  9. Subcellular localization of (latent) transforming growth factor beta and the latent TGF-beta binding protein in rat hepatocytes and hepatic stellate cells.

    PubMed

    Roth-Eichhorn, S; Kühl, K; Gressner, A M

    1998-12-01

    Recently, the existence of the large latent transforming growth factor beta (TGF-beta) complex, consisting of TGF-beta, the N-terminal part of its precursor (latency-associated peptide [LAP]), and the latent TGF-beta binding protein (LTBP), was demonstrated in rat liver parenchymal cells (PC) and stellate cells (HSC). However, in contrast to HSC, in freshly isolated PC, no message of these proteins is detectable. This study was performed to investigate the subcellular distribution of the proteins forming the latent TGF-beta complex in PC and HSC from rat liver to obtain more information about their origin and potential intracellular functions. PC and HSC were isolated from rat liver by protease reperfusion and investigated for TGF-beta1,-2,-3, beta1-LAP, and LTBP-1 after cultivation using double-immunofluorescent staining, followed by high-resolution confocal microscopic analysis. Subcellular fractions obtained by standard differential centrifugation of rat liver homogenate were analyzed using a TGF-beta1 enzyme-linked immunosorbent assay (ELISA) and Western blotting for beta1-LAP and LTBP-1. By confocal microscopy, a diffuse distribution of TGF-beta and LAP in the cytoplasm of PC is noticed, whereas the LTBP immunostaining predominates at plasma membranes. In PC, distinct intracellular granules were superimposed with TGF-beta, LAP, and LTBP stainings identified as lysosomal compartments and mitochondria by ELISA and immunoblotting of subcellular fractions. In HSC, stainings of colocalized TGF-beta, LAP, and LTBP are strongest in the perinuclear area, indicating synthesis and secretion via endoplasmic reticulum and Golgi, respectively. Partially, the proteins were also found in HSC nuclei. During the transformation of HSC to myofibroblasts, LAP and LTBP become strongly colocalized with other components of the cytoskeletal network like smooth muscle--actin, desmin, and talin. The results confirm biochemical data about the existence and expression of the large latent

  10. Comparison of two interferon-gamma release assays (QuantiFERON-TB Gold In-Tube and T-SPOT.TB) in testing for latent tuberculosis infection among HIV-infected adults.

    PubMed

    Sultan, B; Benn, P; Mahungu, T; Young, M; Mercey, D; Morris-Jones, S; Miller, R F

    2013-10-01

    There is currently no 'gold standard' for diagnosis of latent tuberculosis infection (LTBI), and both the tuberculin skin test and interferon-gamma release assays (IGRAs) are used for diagnosis; the latter have a higher sensitivity than tuberculin skin tests for diagnosis of LTBI in HIV-infected individuals with lower CD4 counts. No evidence base exists for selection of IGRA methodology to identify LTBI among human immunodeficiency virus-infected patients in the UK. We prospectively evaluated two commercially available IGRA methods (QuantiFERON-TB Gold In Tube [QFG] and T-SPOT.TB) for testing LTBI among HIV-infected patients potentially nosocomially exposed to an HIV-infected patient with 'smear-positive' pulmonary tuberculosis. Among the exposed patients median CD4 count was 550 cells/µL; 105 (90%) of 117 were receiving antiretroviral therapy, of who 104 (99%) had an undetectable plasma HIV load. IGRAs were positive in 12 patients (10.3%); QFG positive in 11 (9.4%) and T-SPOT.TB positive in six (5.1%); both IGRAs were positive in five patients (4.3%). There was one indeterminate QFG and one borderline T-SPOT.TB result. Concordance between the two IGRAs was moderate (κ = 0.56, 95% confidence interval = 0.27-0.85). IGRAs were positive in only 4 (29%) of 14 patients with previous culture-proven tuberculosis. No patient developed tuberculosis during 20 months of follow-up.

  11. Prevalence and Diagnosis of Latent Tuberculosis Infection in Young Children in the Absence of a Gold Standard

    PubMed Central

    Ascaso, Carlos; Malheiro, Adriana; Bührer, Samira; Martinez-Espinosa, Flor; Abellana, Rosa

    2016-01-01

    Introduction For adequate disease control the World Health Organization has proposed the diagnosis and treatment of latent tuberculous infection (LTBI) in groups of risk of developing the disease such as children. There is no gold standard (GS) test for the diagnosis of LTBI. The objective of this study was to estimate the prevalence of LTBI in young children in contact with a household case of tuberculosis (TB-HCC) and determine the accuracy and precision of the Tuberculin Skin Test (TST) and QuantiFERON-TB Gold in-tube (QFT) used in the absence of a GS. Methods We conducted a cross-sectional study in children up to 6 years of age in Manaus/Brazil during the years 2009–2010. All the children had been vaccinated with the BCG and were classified into two groups according to the presence of a TB-HCC or no known contact with tuberculosis (TB). The variables studied were: the TST and QFT results and the intensity and length of exposure to the index tuberculosis case. We used the latent class model to determine the prevalence of LTBI and the accuracy of the tests. Results Fifty percent of the children with TB-HCC had LTBI, with the prevalence depending on the intensity and length of exposure to the index case. The sensitivity and specificity of TST were 73% [95% confidence interval (CI): 53–91] and 97% (95%CI: 89–100), respectively, versus 53% (95%CI: 41–66) and 81% (95%CI:71–90) for QFT. The positive predictive value of TST in children with TB-HCC was 91% (95%CI: 61–99), being 74% for QFT (95%CI: 47–95). Conclusions This is one of the first studies to estimate the prevalence of LTBI in children and the parameters of the main diagnostic tests using a latent class model. Our results suggest that children in contact with an index case have a high risk of infection. The accuracy and the predictive value of the two tests did not significantly differ. Combined use of the two tests showed scarce improvement in the diagnosis of LTBI. PMID:27783642

  12. Patterns of adolescent sexual behavior predicting young adult sexually transmitted infections: a latent class analysis approach.

    PubMed

    Vasilenko, Sara A; Kugler, Kari C; Butera, Nicole M; Lanza, Stephanie T

    2015-04-01

    Adolescent sexual behavior is multidimensional, yet most studies of the topic use variable-oriented methods that reduce behaviors to a single dimension. In this study, we used a person-oriented approach to model adolescent sexual behavior comprehensively, using data from the National Longitudinal Study of Adolescent Health. We identified five latent classes of adolescent sexual behavior: Abstinent (39%), Oral Sex (10%), Low-Risk (25%), Multi-Partner Normative (12%), and Multi-Partner Early (13%). Membership in riskier classes of sexual behavior was predicted by substance use and depressive symptoms. Class membership was also associated with young adult STI outcomes although these associations differed by gender. Male adolescents' STI rates increased with membership in classes with more risky behaviors whereas females' rates were consistent among all sexually active classes. These findings demonstrate the advantages of examining adolescent sexuality in a way that emphasizes its complexity.

  13. Patterns of Adolescent Sexual Behavior Predicting Young Adult Sexually Transmitted Infections: A Latent Class Analysis Approach

    PubMed Central

    Vasilenko, Sara A.; Kugler, Kari C.; Butera, Nicole M.; Lanza, Stephanie T.

    2014-01-01

    Adolescent sexual behavior is multidimensional, yet most studies of the topic use variable-oriented methods that reduce behaviors to a single dimension. In this study, we used a person-oriented approach to model adolescent sexual behavior comprehensively, using data from the National Longitudinal Study of Adolescent Health. We identified five latent classes of adolescent sexual behavior: Abstinent (39%), Oral Sex (10%), Low-Risk (25%), Multi-Partner Normative (12%), and Multi-Partner Early (13%). Membership in riskier classes of sexual behavior was predicted by substance use and depressive symptoms. Class membership was also associated with young adult STI outcomes although these associations differed by gender. Male adolescents' STI rates increased with membership in classes with more risky behaviors whereas females' rates were consistent among all sexually active classes. These findings demonstrate the advantages of examining adolescent sexuality in a way that emphasizes its complexity. PMID:24449152

  14. 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

  15. Latent tuberculosis infection amongst new recruits to the Chinese army: comparison of ELISPOT assay and tuberculin skin test.

    PubMed

    Wu, Xueqiong; Li, Qiaoke; Yang, Yourong; Zhang, Chuiying; Li, Juan; Zhang, Junxian; Liang, Yan; Cheng, Hongbing; Zhang, Jingzhuan; Zhu, Lin; Zhang, Guangyu; Wang, Lan

    2009-07-01

    In China, latent tuberculosis infection (LTI) is frequent. To protect the health of soldiers and monitor TB infection, new recruits were routinely examined for LTI by tuberculin skin testing (TST). This is the first report on the extent of LTI in the Chinese army comparing TST and enzyme-linked immunospot (ELISPOT) assay. New recruits to the army were interviewed, routinely examined and injected intradermally with purified protein derivative (PPD) in March 2007. At the same time, 100 male soldier volunteers were detected with ELISPOT assay using recombinant CFP-10/ESAT-6 fusion protein (rCFP-10/ESAT-6) as a stimulus. The prevalence of LTI, as estimated by TST and ELISPOT assay, was 41% and 21% of new recruits, respectively. Vaccination scars on the arms could be found in 83% of volunteers with positive TST and 19% of volunteers with negative TST. Five individuals with strongly positive TST of whom 2 had negative ELISPOT were not given chemotherapy, and were observed for 20 months. None developed active TB. The prevalence of LTI in new recruits to the Chinese army is not as high as previously reported. ELISPOT technique may be the most accurate screening method for the TB infection in China, which was not interfered by BCG vaccination.

  16. Performance of QuantiFERON TB gold test compared with the tuberculin skin test for detecting latent tuberculosis infection in lung and heart transplant candidates.

    PubMed

    Mardani, Masoud; Farshidpour, Maham; Nekoonam, Mohsen; Varahram, Fatemeh; Najafizadeh, Katayoon; Mohammadi, Nazila; Sharifkashani, Babak; Gachkar, Latif; Farokhzad, Banafsheh; Droudinia, Atousa; Javanmard, Pedram; Tabarsi, Payam

    2014-04-01

    Evaluation for latent tuberculosis infection is advised before organ transplant. The interferon-gamma release assay has been shown to be more specific than the tuberculin skin test for screening for latent tuberculosis infection. We compared the tuberculin skin test and QuantiFERON-TB Gold In-Tube test for screening for latent tuberculosis infection and agreement between the tests in heart and lung transplant recipients before transplant. Fifty-five adult patients who had been evaluated for heart and lung transplant between September 2011 and September 2012 at Masih Daneshvari Hospital in Iran were prospectively enrolled. We performed the tuberculin skin test and QuantiFERON-TB Gold In-Tube test. Of the 55 patients, 3 (5%) had positive tuberculin skin test results, and 11 (20%) had positive QuantiFERON-TB Gold In-Tube test results. Agreement between the tuberculin skin test and QuantiFERON-TB Gold In-Tube test was fair (Kappa=0.061; 95% CI: - 0.185-0.307) (P = .56). The positivity for QuantiFERON-TB Gold In-Tube test was greater than the positivity for the tuberculin skin test, and QuantiFERON-TB Gold In-Tube test more accurately determined the risk for latent tuberculosis infection. However, a further longitudinal study is necessary to verify that the QFT-G test would predict developing tuberculosis after heart and lung transplant.

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    PubMed

    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.

  19. 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

  20. Gammaherpesvirus latency differentially impacts the generation of primary versus secondary memory CD8+ T cells during subsequent infection.

    PubMed

    Barton, Erik S; Rajkarnikar, Sujana; Langston, P Kent; Price, Madeline J; Grayson, Jason M

    2014-11-01

    Unlike laboratory animals, humans are infected with multiple pathogens, including the highly prevalent herpesviruses. The purpose of these studies was to determine the effect of gammaherpesvirus latency on T cell number and differentiation during subsequent heterologous viral infections. Mice were first infected with murine gammaherpesvirus 68 (MHV68), a model of Epstein-Barr virus (EBV) infection, and then after latency was established, they were challenged with the Armstrong strain of lymphocytic choriomeningitis virus (LCMV). The initial replication of LCMV was lower in latently infected mice, and the maturation of dendritic cells was abated. Although the number of LCMV-specific effector CD8(+) T cells was not altered, they were skewed to a memory phenotype. In contrast, LCMV-specific effector CD4(+) T cells were increased in latently infected mice compared to those in mice infected solely with LCMV. When the memory phase was reached, latently infected mice had an LCMV-specific memory T cell pool that was increased relative to that found in singly infected mice. Importantly, LCMV-specific memory CD8(+) T cells had decreased CD27 and increased killer cell lectin-like receptor G1 (KLRG1) expression. Upon secondary challenge, LCMV-specific secondary effector CD8(+) T cells expanded and cleared the infection. However, the LCMV-specific secondary memory CD8(+) T cell pool was decreased in latently infected animals, abrogating the boosting effect normally observed following rechallenge. Taken together, these results demonstrate that ongoing gammaherpesvirus latency affects the number and phenotype of primary versus secondary memory CD8(+) T cells during acute infection. CD8(+) T cells are critical for the clearance of intracellular pathogens, including viruses, certain bacteria, and tumors. However, current models for memory CD8(+) T cell differentiation are derived from pathogen-free laboratory mice challenged with a single pathogen or vaccine vector. Unlike

  1. Altered T cell surface glycosylation in HIV-1 infection results in increased susceptibility to galectin-1-induced cell death.

    PubMed

    Lantéri, Marion; Giordanengo, Valérie; Hiraoka, Nobuyoshi; Fuzibet, Jean-Gabriel; Auberger, Patrick; Fukuda, Minoru; Baum, Linda G; Lefebvre, Jean-Claude

    2003-12-01

    The massive T cell death that occurs in HIV type 1 (HIV-1) infection contributes profoundly to the pathophysiology associated with AIDS. The mechanisms controlling cell death of both infected and uninfected T cells ("bystander" death) are not completely understood. We have shown that HIV-1 infection of T cells results in altered glycosylation of cell surface glycoproteins; specifically, it decreased sialylation and increased expression of core 2 O-glycans. Galectin-1 is an endogenous human lectin that recognizes these types of glycosylation changes and induces cell death of activated lymphocytes. Therefore we studied the possible contribution of galectin-1 in the pathophysiology of AIDS. O-glycan modifications were investigated on peripheral lymphocytes from AIDS patients. Oligosaccharides from CD43 and CD45 of CEM cells latently infected with HIV-1 were chemically analyzed. Consistent with our previous results, we show that HIV-1 infection results in accumulation of exposed lactosamine residues, oligosaccharides recognized by galectin-1 on cell surface glycoproteins. Both latently HIV-1-infected T cell lines and peripheral CD4 and CD8 T cells from AIDS patients exhibited exposed lactosamine residues and demonstrated marked susceptibility to galectin-1-induced cell death, in contrast to control cultures or cells from uninfected donors. The fraction of cells that died in response to galectin-1 exceeded the fraction of infected cells, indicating that death of uninfected cells occurred. Altered cell surface glycosylation of T cells during HIV-1 infection increases the susceptibility to galectin-1-induced cell death, and this death pathway can contribute to loss of both infected and uninfected T cells in AIDS.

  2. Dynamics of an HBV/HCV infection model with intracellular delay and cell proliferation

    NASA Astrophysics Data System (ADS)

    Zhang, Fengqin; Li, Jianquan; Zheng, Chongwu; Wang, Lin

    2017-01-01

    A new mathematical model of hepatitis B/C virus (HBV/HCV) infection which incorporates the proliferation of healthy hepatocyte cells and the latent period of infected hepatocyte cells is proposed and studied. The dynamics is analyzed via Pontryagin's method and a newly proposed alternative geometric stability switch criterion. Sharp conditions ensuring stability of the infection persistent equilibrium are derived by applying Pontryagin's method. Using the intracellular delay as the bifurcation parameter and applying an alternative geometric stability switch criterion, we show that the HBV/HCV infection model undergoes stability switches. Furthermore, numerical simulations illustrate that the intracellular delay can induce complex dynamics such as persistence bubbles and chaos.

  3. Acquired latent tuberculosis infection in psoriasis patients treated with etanercept in the People’s Republic of China

    PubMed Central

    Li, Cheng-Rang; Mao, Qiu-Xia; Chen, Min; Jia, Wei-Xue; Yao, Xu; Feng, Su-Ying; Jia, Hong; Gong, Juan-Qin; Yang, Xue-Yuan

    2015-01-01

    Background TNF-α plays a key role in host defense against mycobacterial infection, and patients receiving TNF-α blocker treatment have increased susceptibility to tuberculosis disease. In the People’s Republic of China, an intermediate tuberculosis-burden country, the latent tuberculosis infection (LTBI) risk in patients with psoriasis who are treated with etanercept, the safest kind of TNF-α blocker, is unknown. Objectives This study reports the LTBI risk in patients with psoriasis after etanercept treatment and aims to answer the question of how often rescreening for LTBI should be done in order to reduce active tuberculosis infection of patients and further reduce the incidence of active tuberculosis disease. Patients and methods: This retrospective review evaluated patients with moderate-to-severe chronic plaque psoriasis between 2009 and 2013. All patients were excluded tuberculosis infection and received etanercept 25 mg twice weekly, then the patients were checked for LTBI 3 months after etanercept treatment to observe the incidence of LTBI and assess the need for rescreening for LTBI every 3 months. Results We retrospectively analyzed 192 patients with psoriasis with moderate-to-severe chronic plaque whose tuberculin skin test and chest X-rays were negative and who received etanercept 25 mg twice weekly. Eighteen of them were excluded because they received less than 3 months of etanercept therapy. After treatment with etanercept, four patients were found to have LTBI. Conclusion In this study, the incidence of LTBI after 3 months was four in 192 (2.1%), which is higher than the annual incidence of LTBI in the People’s Republic of China (0.72%), so LTBI could be expected to occur within 3 months in psoriasis patients on etanercept. Periodic screening for LTBI in the therapy course, as well as before initiating treatment, is necessary in those patients who use a TNF-α blocker. We recommend rescreening for LTBI every 3 months. PMID:26508833

  4. Quantitative IFN-γ and IL-2 Response Associated with Latent Tuberculosis Test Discordance in HIV-infected Pregnant Women.

    PubMed

    Mathad, Jyoti S; Bhosale, Ramesh; Balasubramanian, Usha; Kanade, Savita; Mave, Vidya; Suryavanshi, Nishi; Gupte, Nikhil; Joshi, Samir; Chandanwale, Ajay; Dupnik, Kathryn M; Kulkarni, Vandana; Deshpande, Prasad; Fitzgerald, Daniel W; Gupta, Amita

    2016-06-15

    Pregnant women with latent tuberculosis infection (LTBI) are at high risk for development of TB, especially if infected with HIV. To assess the performance of LTBI tests in pregnant and postpartum women infected with HIV, investigate the immunology behind discordance in pregnancy, and explore the implications for the development of postpartum TB. We screened pregnant women in their second/third trimester and at delivery for LTBI using the tuberculin skin test (TST) and IFN-γ release assay (IGRA) (QuantiFERON Gold). A subset of antepartum women had longitudinal testing, with repeat testing at delivery and postpartum and additional cytokines measured from the IGRA supernatant. The kappa statistic and Wilcoxon rank sum test were used to determine agreement and comparison of cytokine concentrations, respectively. Of 252 enrolled, 71 (28%) women had a positive IGRA but only 27 (10%) had a positive TST (P < 0.005). There was 75% agreement (kappa, 0.25). When stratified by pregnancy versus delivery, 20% had IGRA(+)/TST(-) discordance at each time point. A positive IGRA was associated with known TB contact (odds ratio, 3.6; confidence interval, 1.2-11.1; P = 0.02). Compared with IGRA(+)/TST(+), women with IGRA(+)/TST(-) discordance had significantly less IFN-γ (1.85 vs. 3.48 IU/ml; P = 0.02) and IL-2 (46.17 vs. 84.03 pg/ml; P = 0.01). Five developed postpartum TB, of which three had IGRA(+)/TST(-) discordance during pregnancy. Choice of LTBI test in pregnant women infected with HIV affects results. Pregnant women with IGRA(+)/TST(-) discordance had less IFN-γ and IL-2 than those with concordant-positive results and may represent an especially high-risk subset for the development of active TB postpartum.

  5. Intention of physicians to implement guidelines for screening and treatment of latent tuberculosis infection in HIV-infected patients in The Netherlands: a mixed-method design.

    PubMed

    Evenblij, Kirsten; Verbon, Annelies; van Leth, Frank

    2016-09-01

    All newly diagnosed HIV-infected patients in the Netherlands should be screened for latent tuberculosis infection (LTBI) and offered preventive therapy if infected without evidence of active tuberculosis. This guideline, endorsed by the national professional body of HIV physicians is in line with international recommendations, and based on the increased risk of progression from LTBI to active tuberculosis in HIV-infected patients. The objective of the study is to assess the intention of HIV physicians to implement this national guideline. A mixed method design triangulating results from two surveys among all (n = 80) HIV physicians in The Netherlands and qualitative interviews among 11 Dutch HIV physicians performed in 2014. The majority of physicians used a risk-stratification approach based on individual a priori risk of tuberculosis to identify HIV-infected patients for LTBI screening, rather than screening all new HIV-infected patients. The intended and actual provision of preventive treatment was low, due to expressed doubts on the accuracy of diagnostic tools for LTBI. Interviewees reported that the guidelines did not match their clinical experience and lacked evidence for the recommendations. Screening for and treatment of LTBI was approached at a patient-level only. None of the interviewees referred to potential public health implications of the guidelines. Intended implementation of the national HIV-TB guidelines in the Netherlands is poor, due to a disconnect between clinical practice and evidence-based recommendations in the guideline. There is an urgent need to reconcile the views of HIV-physicians, public health experts, and guideline committee members, regarding the best strategy to address HIV-TB co-infection in the Netherlands.

  6. '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.

  7. Prevalence and treatment of latent tuberculosis infection among newly arrived refugees in San Diego County, January 2010-October 2012.

    PubMed

    Bennett, Rachel J; Brodine, Stephanie; Waalen, Jill; Moser, Kathleen; Rodwell, Timothy C

    2014-04-01

    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. 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. 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. 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.

  8. Levels of Epstein-Barr virus DNA in lymphoblastoid cell lines are correlated with frequencies of spontaneous lytic growth but not with levels of expression of EBNA-1, EBNA-2, or latent membrane protein.

    PubMed Central

    Metzenberg, S

    1990-01-01

    The process of Epstein-Barr virus (EBV)-induced transformation of human B lymphocytes results in a cell line that is a mixture of latently and lytically infected cells, with the lytic cells composing roughly 5% to less than 0.0001% of the overall population. A set of nine normal lymphoblastoid cell lines that span a 100- to 200-fold range in average EBV DNA content were studied, and the frequency with which these cells entered a lytic phase of viral growth correlated with their EBV DNA copy number (as a population average). However, neither factor correlated with the levels of expression of transcript for the viral genes EBNA-1, EBNA-2, and latent membrane protein, nor did they correlate with the levels of EBNA-2 protein and latent membrane protein. The rate at which a cell line enters into lytic growth spontaneously is therefore not dependent on the overall steady-state levels of expression of these latent-phase genes. Images PMID:2152830

  9. Inhibition of Latent Membrane Protein 1 Impairs the Growth and Tumorigenesis of Latency II Epstein-Barr Virus-Transformed T Cells

    PubMed Central

    Ndour, Papa Alioune; Brocqueville, Guillaume; Ouk, Tan-Sothéa; Goormachtigh, Gautier; Morales, Olivier; Mougel, Alexandra; Bertout, Julie; Melnyk, Oleg; Fafeur, Véronique; Feuillard, Jean; Coll, Jean

    2012-01-01

    Epstein-Barr virus (EBV) is a common human herpesvirus. Infection with EBV is associated with several human malignancies in which the virus expresses a set of latent proteins, among which is latent membrane protein 1 (LMP1). LMP1 is able to transform numerous cell types and is considered the main oncogenic protein of EBV. The mechanism of action is based on mimicry of activated members of the tumor necrosis factor (TNF) receptor superfamily, through the ability of LMP1 to bind similar adapters and to activate signaling pathways. We previously generated two unique models: a monocytic cell line and a lymphocytic (NC5) cell line immortalized by EBV that expresses the type II latency program. Here we generated LMP1 dominant negative forms (DNs), based on fusion between green fluorescent protein (GFP) and transformation effector site 1 (TES1) or TES2 of LMP1. Then we generated cell lines conditionally expressing these DNs. These DNs inhibit NF-κB and Akt pathways, resulting in the impairment of survival processes and increased apoptosis in these cell lines. This proapoptotic effect is due to reduced interaction of LMP1 with specific adapters and the recruitment of these adapters to DNs, which enable the generation of an apoptotic complex involving TRADD, FADD, and caspase 8. Similar results were obtained with cell lines displaying a latency III program in which LMP1-DNs decrease cell viability. Finally, we prove that synthetic peptides display similar inhibitory effects in EBV-infected cells. DNs derived from LMP1 could be used to develop therapeutic approaches for malignant diseases associated with EBV. PMID:22258264

  10. Inhibition of latent membrane protein 1 impairs the growth and tumorigenesis of latency II Epstein-Barr virus-transformed T cells.

    PubMed

    Ndour, Papa Alioune; Brocqueville, Guillaume; Ouk, Tan-Sothéa; Goormachtigh, Gautier; Morales, Olivier; Mougel, Alexandra; Bertout, Julie; Melnyk, Oleg; Fafeur, Véronique; Feuillard, Jean; Coll, Jean; Adriaenssens, Eric

    2012-04-01

    Epstein-Barr virus (EBV) is a common human herpesvirus. Infection with EBV is associated with several human malignancies in which the virus expresses a set of latent proteins, among which is latent membrane protein 1 (LMP1). LMP1 is able to transform numerous cell types and is considered the main oncogenic protein of EBV. The mechanism of action is based on mimicry of activated members of the tumor necrosis factor (TNF) receptor superfamily, through the ability of LMP1 to bind similar adapters and to activate signaling pathways. We previously generated two unique models: a monocytic cell line and a lymphocytic (NC5) cell line immortalized by EBV that expresses the type II latency program. Here we generated LMP1 dominant negative forms (DNs), based on fusion between green fluorescent protein (GFP) and transformation effector site 1 (TES1) or TES2 of LMP1. Then we generated cell lines conditionally expressing these DNs. These DNs inhibit NF-κB and Akt pathways, resulting in the impairment of survival processes and increased apoptosis in these cell lines. This proapoptotic effect is due to reduced interaction of LMP1 with specific adapters and the recruitment of these adapters to DNs, which enable the generation of an apoptotic complex involving TRADD, FADD, and caspase 8. Similar results were obtained with cell lines displaying a latency III program in which LMP1-DNs decrease cell viability. Finally, we prove that synthetic peptides display similar inhibitory effects in EBV-infected cells. DNs derived from LMP1 could be used to develop therapeutic approaches for malignant diseases associated with EBV.

  11. KSHV infects a subset of human tonsillar B cells, driving proliferation and plasmablast differentiation

    PubMed Central

    Hassman, Lynn M.; Ellison, Thomas J.; Kedes, Dean H.

    2011-01-01

    Kaposi sarcoma–associated herpesvirus (KSHV; also known as HHV8) is the causative agent of two B cell tumors, multicentric Castleman disease (MCD) and primary effusion lymphoma (PEL). However, little is known about the nature of the specific B cell subtype(s) most susceptible to infection. Identifying these cells would provide direct insight into KSHV transmission and virus-induced transformation. To identify this subset and to determine whether infection alters its cellular phenotype, we exposed human tonsillar cells to KSHV and characterized infected cells using high-throughput multispectral imaging flow cytometry (MIFC). Stable expression of the virally encoded latency-associated nuclear antigen (LANA), a marker of latent KSHV infection, was observed predominantly in cells expressing the l light chain of the B cell receptor. These LANA+ B cells proliferated and exhibited similarities to the cells characteristic of MCD (IgMl-expressing plasmablasts), including blasting morphology with elevated expression of Ki67, variable expression of CD27, and high levels of IgM and IL-6 receptor. Furthermore, the proportion of infected cells showing a blasting phenotype increased upon addition of exogenous IL-6. Our data lead us to propose that oral transmission of KSHV involves the latent infection of a subset of tonsillar IgMl-expressing B cells, which then proliferate as they acquire the plasmablast phenotype characteristic of MCD. PMID:21245574

  12. Insights from the computational analysis of CD271 glycation in mescenchymal stem cells in diabetes mellitus as a predisposition to latent tuberculosis.

    PubMed

    Bhattacharyya, Rajasri; Shukla, Misha; Nagra, Sachin; Banerjee, Dibyajyoti

    2013-01-01

    Diabetes mellitus is considered as a predisposition factor for active tuberculosis and is known to activate the latent form of tuberculosis. However, the causative association of latent tuberculosis with diabetes is not conclusively established. Therefore, it is of interest to relate their predisposition. We describe the glycation pattern of mescenchymal stem cell surface markers as CD271+/CD45-mescenchymal stem cell is known to be associated with latent tuberculosis. We show that the lysine residues important for function of CD271 death domain are predicted to be and glycated. These observations help to discuss the role of CD271 and glycation to modulate the genesis of latent tuberculosis in chronic diabetic mellitus.

  13. 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

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

    PubMed

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

    2015-06-01

    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. 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. 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). 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. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

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

    PubMed

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

    2015-06-01

    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. 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 help NK cells to act

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

    PubMed Central

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

    2016-01-01

    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. Here 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

  17. Added value of QuantiFERON TB-gold in-tube for detecting latent tuberculosis infection among persons living with HIV/AIDS.

    PubMed

    Souza, Josiane Maria Oliveira; Evangelista, Maria do Socorro Nantua; Trajman, Anete

    2014-01-01

    To evaluate the added value of QuantiFERON TB-Gold in-Tube (QTF-GIT) over the tuberculin skin testing (TST) for detecting latent tuberculosis (TB) infection (LTBI) among patients with AIDS in a city with a low TB incidence rate (11.1/100,000 inhabitants) and universal BCG coverage. Three hundred consecutive patients with AIDS in eight outpatient sexually transmitted disease public clinics in Brasilia were submitted to QFT-IT and TST between May 2011 and March 2013. A positive result of either test was considered to be LTBI. Median CD4-cell count was 477.5 cells/mm(3); 295 (98.3%) were using antiretroviral therapy. Eighteen patients (6%, 95% CI: 3.6%-9.3%) had LTBI, of whom 4 (1.3%, 95% CI: 0.04%-2.63%) had only a positive TST, 8 (2.7%, 95% CI: 0.8%-4.5%) had only a QFT-GIT positive test, and 6 (2%, 95% CI: 0.4%-3.6%) had positive results for both tests. This represents an 81.8% relative increase in LTBI detection when QFT-GIT is added to TST. The concordance between both tests was 96% (k = 0.48). The QFT-GIT alone was more effective to detect LTBI than TST alone and had an 81% added value as an add-on sequential test in this population with mild immunosuppression. The cost-effectiveness of these strategies remains to be evaluated.

  18. Interrelationship of Primary Virus Replication, Level of Latency, and Time to Reactivation in the Trigeminal Ganglia of Latently Infected Mice.

    PubMed

    Matundan, Harry H; Mott, Kevin R; Allen, Sariah J; Wang, Shaohui; Bresee, Catherine J; Ghiasi, Yasamin N; Town, Terrence; Wechsler, Steven L; Ghiasi, Homayon

    2016-10-15

    We sought to determine the possibility of an interrelationship between primary virus replication in the eye, the level of viral DNA in the trigeminal ganglia (TG) during latency, and the amount of virus reactivation following ocular herpes simplex virus type 1 (HSV-1) infection. Mice were infected with virulent (McKrae) or avirulent (KOS and RE) strains of HSV-1, and virus titers in the eyes and TG during primary infection, level of viral gB DNA in TG on day 28 postinfection (p.i.), and virus reactivation on day 28 p.i. as measured by explant reactivation were calculated. Our results suggest that the avirulent strains of HSV-1, even after corneal scarification, had lower virus titers in the eye, had less latency in the TG, and took a longer time to reactivate than virulent strains of HSV-1. The time to explant reactivation of avirulent strains of HSV-1 was similar to that of the virulent LAT((-)) McKrae-derived mutant. The viral dose with the McKrae strain of HSV-1 affected the level of viral DNA and time to explant reactivation. Overall, our results suggest that there is no absolute correlation between primary virus titer in the eye and TG and the level of viral DNA in latent TG and time to reactivation. Very little is known regarding the interrelationship between primary virus replication in the eye, the level of latency in TG, and the time to reactivate in the mouse model. This study was designed to answer these questions. Our results point to the absence of any correlation between the level of primary virus replication and the level of viral DNA during latency, and neither was an indicator of how rapidly the virus reactivated following explant TG-induced reactivation. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  19. Interrelationship of Primary Virus Replication, Level of Latency, and Time to Reactivation in the Trigeminal Ganglia of Latently Infected Mice

    PubMed Central

    Matundan, Harry H.; Mott, Kevin R.; Allen, Sariah J.; Wang, Shaohui; Bresee, Catherine J.; Ghiasi, Yasamin N.; Town, Terrence

    2016-01-01

    ABSTRACT We sought to determine the possibility of an interrelationship between primary virus replication in the eye, the level of viral DNA in the trigeminal ganglia (TG) during latency, and the amount of virus reactivation following ocular herpes simplex virus type 1 (HSV-1) infection. Mice were infected with virulent (McKrae) or avirulent (KOS and RE) strains of HSV-1, and virus titers in the eyes and TG during primary infection, level of viral gB DNA in TG on day 28 postinfection (p.i.), and virus reactivation on day 28 p.i. as measured by explant reactivation were calculated. Our results suggest that the avirulent strains of HSV-1, even after corneal scarification, had lower virus titers in the eye, had less latency in the TG, and took a longer time to reactivate than virulent strains of HSV-1. The time to explant reactivation of avirulent strains of HSV-1 was similar to that of the virulent LAT(−) McKrae-derived mutant. The viral dose with the McKrae strain of HSV-1 affected the level of viral DNA and time to explant reactivation. Overall, our results suggest that there is no absolute correlation between primary virus titer in the eye and TG and the level of viral DNA in latent TG and time to reactivation. IMPORTANCE Very little is known regarding the interrelationship between primary virus replication in the eye, the level of latency in TG, and the time to reactivate in the mouse model. This study was designed to answer these questions. Our results point to the absence of any correlation between the level of primary virus replication and the level of viral DNA during latency, and neither was an indicator of how rapidly the virus reactivated following explant TG-induced reactivation. PMID:27512072

  20. Antibody-Dependent Cellular Cytotoxicity against Reactivated HIV-1-Infected Cells.

    PubMed

    Lee, Wen Shi; Richard, Jonathan; Lichtfuss, Marit; Smith, Amos B; Park, Jongwoo; Courter, Joel R; Melillo, Bruno N; Sodroski, Joseph G; Kaufmann, Daniel E; Finzi, Andrés; Parsons, Matthew S; Kent, Stephen J

    2015-12-09

    Lifelong antiretroviral therapy (ART) for HIV-1 does not diminish the established latent reservoir. A possible cure approach is to reactivate the quiescent genome from latency and utilize immune responses to eliminate cells harboring reactivated HIV-1. It is not known whether antibodies within HIV-1-infected individuals can recognize and eliminate cells reactivated from latency through antibody-dependent cellular cytotoxicity (ADCC). We found that reactivation of HIV-1 expression in the latently infected ACH-2 cell line elicited antibody-mediated NK cell activation but did not result in antibody-mediated killing. The lack of CD4 expression on these HIV-1 envelope (Env)-expressing cells likely resulted in poor recognition of CD4-induced antibody epitopes on Env. To examine this further, cultured primary CD4(+) T cells from HIV-1(+) subjects were used as targets for ADCC. These ex vivo-expanded primary cells were modestly susceptible to ADCC mediated by autologous or heterologous HIV-1(+) serum antibodies. Importantly, ADCC mediated against these primary cells could be enhanced following incubation with a CD4-mimetic compound (JP-III-48) that exposes CD4-induced antibody epitopes on Env. Our studies suggest that with sufficient reactivation and expression of appropriate Env epitopes, primary HIV-1-infected cells can be targets for ADCC mediated by autologous serum antibodies and innate effector cells. The results of this study suggest that further investigation into the potential of ADCC to eliminate reactivated latently infected cells is warranted. An HIV-1 cure remains elusive due to the persistence of long-lived latently infected cells. An HIV-1 cure strategy, termed "shock and kill," aims to reactivate HIV-1 expression in latently infected cells and subsequently eliminate the reactivated cells through immune-mediated killing. While recent research efforts have focused on reversing HIV-1 latency, it remains unclear whether preexisting immune responses within HIV-1

  1. Antibody-Dependent Cellular Cytotoxicity against Reactivated HIV-1-Infected Cells

    PubMed Central

    Lee, Wen Shi; Richard, Jonathan; Lichtfuss, Marit; Smith, Amos B.; Park, Jongwoo; Courter, Joel R.; Melillo, Bruno N.; Sodroski, Joseph G.; Kaufmann, Daniel E.; Parsons, Matthew S.

    2015-01-01

    ABSTRACT Lifelong antiretroviral therapy (ART) for HIV-1 does not diminish the established latent reservoir. A possible cure approach is to reactivate the quiescent genome from latency and utilize immune responses to eliminate cells harboring reactivated HIV-1. It is not known whether antibodies within HIV-1-infected individuals can recognize and eliminate cells reactivated from latency through antibody-dependent cellular cytotoxicity (ADCC). We found that reactivation of HIV-1 expression in the latently infected ACH-2 cell line elicited antibody-mediated NK cell activation but did not result in antibody-mediated killing. The lack of CD4 expression on these HIV-1 envelope (Env)-expressing cells likely resulted in poor recognition of CD4-induced antibody epitopes on Env. To examine this further, cultured primary CD4+ T cells from HIV-1+ subjects were used as targets for ADCC. These ex vivo-expanded primary cells were modestly susceptible to ADCC mediated by autologous or heterologous HIV-1+ serum antibodies. Importantly, ADCC mediated against these primary cells could be enhanced following incubation with a CD4-mimetic compound (JP-III-48) that exposes CD4-induced antibody epitopes on Env. Our studies suggest that with sufficient reactivation and expression of appropriate Env epitopes, primary HIV-1-infected cells can be targets for ADCC mediated by autologous serum antibodies and innate effector cells. The results of this study suggest that further investigation into the potential of ADCC to eliminate reactivated latently infected cells is warranted. IMPORTANCE An HIV-1 cure remains elusive due to the persistence of long-lived latently infected cells. An HIV-1 cure strategy, termed “shock and kill,” aims to reactivate HIV-1 expression in latently infected cells and subsequently eliminate the reactivated cells through immune-mediated killing. While recent research efforts have focused on reversing HIV-1 latency, it remains unclear whether preexisting immune

  2. Enhanced aerobic glycolysis of nasopharyngeal carcinoma cells by Epstein-Barr virus latent membrane protein 1.

    PubMed

    Sung, Wei-Wen; Chen, Peir-Rong; Liao, Ming-Hui; Lee, Jeng-Woei

    2017-10-01

    Latent membrane protein 1 (LMP1) is a principal viral oncoprotein in Epstein-Barr virus (EBV)-associated malignancies, including nasopharyngeal carcinoma (NPC), which acts through regulating tumorigenesis and metabolic reprogramming of cancers. In the presence of oxygen, we demonstrated that glucose consumption, lactate production and lactate dehydrogenase (LDH) activity were significantly increased upon LMP1 expression in NPC cells and in a LMP1 variant derived from NPC patients-transformed BALB/c-3T3 cells. The amounts of the α subunit of hypoxia-inducible factor-1 (HIF-1α), a key regulator of aerobic glycolysis, and its targets, pyruvate dehydrogenase kinase 1 (PDK1) and the pyruvate kinase M2 (PKM2) isoform, were also consistently elevated by LMP1. Moreover, in parallel with reductions in the oxygen consumption rate and mitochondrial membrane potential in cells, an augmented extracellular lactate concentration was observed due to LMP1 induction. In conclusion, our results proved facilitation of the Warburg effect by LMP1 through alteration of mitochondrial function in NPC cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Characterization of CD4 and CD8 T cells producing IFN-γ in human latent and active tuberculosis.

    PubMed

    Rueda, Cesar M; Marín, Nancy D; García, Luis F; Rojas, Mauricio

    2010-11-01

    Patients with pulmonary tuberculosis (PTB) frequently have reduced IFN-γ production in response to mycobacterial antigens, compared to individuals with latent Mycobacterium tuberculosis infection (LTBi). However, it is not clear whether this reduced responsiveness is restricted to a particular T cell subset. Herein, PBMCs from 26 PTB patients, 30 household contacts (HHCs) of PTB, and 30 tuberculin positive (TST+) healthy subjects not recently exposed to PTB, were stained with CFSE and stimulated non-specific (PPD) for 120 h, and specific (CFP-10/ESAT-6) and latency (HSpX) mycobacterial antigens for 144 h and the percentage of CD4(+) and CD8(+)IFN-γ(+) T cells responding determined by flow cytometry, in addition to their memory phenotype by the CD45RO and CD27 expression. PTB had decreased frequency of both CD4(+) and CD8(+) precursor cells, as well as decreased number of CD4(+)IFN-γ(+) cells in response to all antigens, whereas CD8(+)IFN-γ(+) cells were decreased in response to PPD and ESAT-6, but not to CFP-10 and HSpX. HHCs exhibited the highest precursor frequencies and IFN-γ responses, irrespective of the antigen employed. The CD4(+)/CD8(+) cell ratios showed that in response to PPD CD4(+) precursor and IFN-γ-producer