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Full-Text Articles in Virology

Microrna Mir-155 Is Necessary For Efficient Gammaherpesvirus Reactivation From Latency, But Not For Establishment Of Latency, Rebecca L. Crepeau, Peisheng Zhang, Edward J. Usherwood Jun 2016

Microrna Mir-155 Is Necessary For Efficient Gammaherpesvirus Reactivation From Latency, But Not For Establishment Of Latency, Rebecca L. Crepeau, Peisheng Zhang, Edward J. Usherwood

Dartmouth Scholarship

MicroRNA-155 (miR-155) has been shown to play significant roles in the immune response, including in the formation of germinal centers (GC) and the development and maturation of T follicular helper (Tfh) cells. There is in vitro evidence to support a critical role for cellular miR-155 and viral miR-155 homologs in the establishment of gammaherpesvirus latency in B cells. We sought to determine the contribution of miR-155 to the establishment and maintenance of latency in vivousing murine gammaherpesvirus (MHV-68) infection. MHV-68-infected mice deficient in miR-155 exhibited decreases in GC B cells and Tfh cells. However, the frequencies of spleen cells …


Herpes Simplex Virus And Interferon Signaling Induce Novel Autophagic Clusters In Sensory Neurons, Sarah Katzenell, David A. Leib Feb 2016

Herpes Simplex Virus And Interferon Signaling Induce Novel Autophagic Clusters In Sensory Neurons, Sarah Katzenell, David A. Leib

Dartmouth Scholarship

Herpes simplex virus 1 (HSV-1) establishes lifelong infection in the neurons of trigeminal ganglia (TG), cycling between productive infection and latency. Neuronal antiviral responses are driven by type I interferon (IFN) and are crucial to controlling HSV-1 virulence. Autophagy also plays a role in this neuronal antiviral response, but the mechanism remains obscure. In this study, HSV-1 infection of murine TG neurons triggered unusual clusters of autophagosomes, predominantly in neurons lacking detectable HSV-1 antigen. Treatment of neurons with IFN-β induced a similar response, and cluster formation by infection or IFN treatment was dependent upon an intact IFN-signaling pathway. The autophagic …


Role Of The Dna Sensor Sting In Protection From Lethal Infection Following Corneal And Intracerebral Challenge With Herpes Simplex Virus 1, Zachary M. Parker, Aisling A. Murphy, David. A. Leib Aug 2015

Role Of The Dna Sensor Sting In Protection From Lethal Infection Following Corneal And Intracerebral Challenge With Herpes Simplex Virus 1, Zachary M. Parker, Aisling A. Murphy, David. A. Leib

Dartmouth Scholarship

STING is a protein in the cytosolic DNA and cyclic dinucleotide sensor pathway that is critical for the initiation of innate responses to infection by various pathogens. Consistent with this, herpes simplex virus 1 (HSV-1) causes invariable and rapid lethality in STING-deficient (STING(-/-)) mice following intravenous (i.v.) infection. In this study, using real-time bioluminescence imaging and virological assays, as expected, we demonstrated that STING(-/-) mice support greater replication and spread in ocular tissues and the nervous system. In contrast, they did not succumb to challenge via the corneal route even with high titers of a virus that was routinely lethal …


Selective Involvement Of The Checkpoint Regulator Vista In Suppression Of B-Cell, But Not T-Cell, Responsiveness By Monocytic Myeloid-Derived Suppressor Cells From Mice Infected With An Immunodeficiency-Causing Retrovirus, Kathy A. Green, Li Wang, Randolph J. Noelle, William R. Green Jul 2015

Selective Involvement Of The Checkpoint Regulator Vista In Suppression Of B-Cell, But Not T-Cell, Responsiveness By Monocytic Myeloid-Derived Suppressor Cells From Mice Infected With An Immunodeficiency-Causing Retrovirus, Kathy A. Green, Li Wang, Randolph J. Noelle, William R. Green

Dartmouth Scholarship

Inhibition of T-cell responses in tumor microenvironments by myeloid-derived suppressor cells (MDSCs) is widely accepted. We demonstrated augmentation of monocytic MDSCs whose suppression of not only T-cell, but also B-cell, responsiveness paralleled the immunodeficiency during LP-BM5 retrovirus infection. MDSCs inhibited T cells by inducible nitric oxide synthase (iNOS)/nitric oxide (NO), but uniquely, inhibition of B cells was ~50% dependent each on iNOS/NO and the MDSC-expressed negative-checkpoint regulator VISTA. Blockade with a combination of iNOS/NO and VISTA caused additive or synergistic abrogation of MDSC-mediated suppression of B-cell responsiveness.


Intrinsic Innate Immunity Fails To Control Herpes Simplex Virus And Vesicular Stomatitis Virus Replication In Sensory Neurons And Fibroblasts, Pamela C. Rosato, David A. Leib Jun 2014

Intrinsic Innate Immunity Fails To Control Herpes Simplex Virus And Vesicular Stomatitis Virus Replication In Sensory Neurons And Fibroblasts, Pamela C. Rosato, David A. Leib

Dartmouth Scholarship

Herpes simplex virus 1 (HSV-1) establishes lifelong latent infections in the sensory neurons of the trigeminal ganglia (TG), wherein it retains the capacity to reactivate. The interferon (IFN)-driven antiviral response is critical for the control of HSV-1 acute replication. We therefore sought to further investigate this response in TG neurons cultured from adult mice deficient in a variety of IFN signaling components. Parallel experiments were also performed in fibroblasts isolated concurrently. We showed that HSV-1 replication was comparable in wild-type (WT) and IFN signaling-deficient neurons and fibroblasts. Unexpectedly, a similar pattern was observed for the IFN-sensitive vesicular stomatitis virus (VSV). …


Use Of Irf-3 And/Or Irf-7 Knockout Mice To Study Viral Pathogenesis: Lessons From A Murine Retrovirus-Induced Aids Model, Megan A. O'Connor, William R. Green Dec 2013

Use Of Irf-3 And/Or Irf-7 Knockout Mice To Study Viral Pathogenesis: Lessons From A Murine Retrovirus-Induced Aids Model, Megan A. O'Connor, William R. Green

Dartmouth Scholarship

Interferon regulatory factor (IRF) regulation of the type I interferon response has not been extensively explored in murine retroviral infections. IRF-3(-/-) and select IRF-3/7(-/-) mice were resistant to LP-BM5-induced pathogenesis. However, further analyses strongly suggested that resistance could be attributed to strain 129-specific contamination of the known retrovirus resistance gene Fv1. Therefore, caution should be taken when interpreting phenotypes observed in these knockout mice, as strain 129-derived genetic polymorphisms may explain observed differences.


Inhibition Of The Host Translation Shutoff Response By Herpes Simplex Virus 1 Triggers Nuclear Envelope-Derived Autophagy, Kerstin Radtke, Luc English, Christiane Rondeau, David Leib Jan 2013

Inhibition Of The Host Translation Shutoff Response By Herpes Simplex Virus 1 Triggers Nuclear Envelope-Derived Autophagy, Kerstin Radtke, Luc English, Christiane Rondeau, David Leib

Dartmouth Scholarship

Macroautophagy is a cellular pathway that degrades intracellular pathogens and contributes to antigen presentation. Herpes simplex virus 1 (HSV-1) infection triggers both macroautophagy and an additional form of autophagy that uses the nuclear envelope as a source of membrane. The present study constitutes the first in-depth analysis of nuclear envelope-derived autophagy (NEDA). We established LC3a as a marker that allowed us to distinguish between NEDA and macroautophagy in both immunofluorescence and flow cytometry. NEDA was observed in many different cell types, indicating that it is a general response to HSV-1 infection. This autophagic pathway is known to depend on the …


Myeloid-Derived Suppressor Cells In Murine Retrovirus-Induced Aids Inhibit T- And B-Cell Responses In Vitro That Are Used To Define The Immunodeficiency, Kathy A. Green, W. James Cook, William R. Green Dec 2012

Myeloid-Derived Suppressor Cells In Murine Retrovirus-Induced Aids Inhibit T- And B-Cell Responses In Vitro That Are Used To Define The Immunodeficiency, Kathy A. Green, W. James Cook, William R. Green

Dartmouth Scholarship

Myeloid-derived suppressor cells (MDSCs) have been characterized in several disease settings, especially in many tumor systems. Compared to their involvement in tumor microenvironments, however, MDSCs have been less well studied in their responses to infectious disease processes, in particular to retroviruses that induce immunodeficiency. Here, we demonstrate for the first time the development of a highly immunosuppressive MDSC population that is dependent on infection by the LP-BM5 retrovirus, which causes murine acquired immunodeficiency. These MDSCs express a cell surface marker signature (CD11b Gr-1 Ly6C ) characteristic of monocyte-type MDSCs. Such MDSCs profoundly inhibit immune responsiveness by a cell dose- and …


Corneal Replication Is An Interferon Response-Independent Bottleneck For Virulence Of Herpes Simplex Virus 1 In The Absence Of Virion Host Shutoff, Tracy J. Pasieka, Vineet D. Menachery, Pamela C. Rosato, David A. Leib May 2012

Corneal Replication Is An Interferon Response-Independent Bottleneck For Virulence Of Herpes Simplex Virus 1 In The Absence Of Virion Host Shutoff, Tracy J. Pasieka, Vineet D. Menachery, Pamela C. Rosato, David A. Leib

Dartmouth Scholarship

Herpes simplex viruses lacking the virion host shutoff function (Δvhs) are avirulent and hypersensitive to type I and type II interferon (IFN). In this study, we demonstrate that even in the absence of IFN responses in AG129 (IFN-αβγR−/−) mice, Δvhs remains highly attenuated via corneal infection but is fully virulent via intracranial infection. The data demonstrate that the interferon-independent inherent replication defect of Δvhs has a significant impact upon peripheral replication and neuroinvasion.


Interferon Regulatory Factor 3-Dependent Pathways Are Critical For Control Of Herpes Simplex Virus Type 1 Central Nervous System Infection, Vineet D. Menachery, Tracy J. Pasieka, David A. Leib Oct 2010

Interferon Regulatory Factor 3-Dependent Pathways Are Critical For Control Of Herpes Simplex Virus Type 1 Central Nervous System Infection, Vineet D. Menachery, Tracy J. Pasieka, David A. Leib

Dartmouth Scholarship

The initiation of the immune response at the cellular level relies on specific recognition molecules to rapidly signal viral infection via interferon (IFN) regulatory factor 3 (IRF-3)-dependent pathways. The absence of IRF-3 would be expected to render such pathways inoperative and thereby significantly affect viral infection. Unexpectedly, a previous study found no significant change in herpes simplex virus (HSV) pathogenesis in IRF-3−/− mice following intravenous HSV type 1 (HSV-1) challenge (K. Honda, H. Yanai, H. Negishi, M. Asagiri, M. Sato, T. Mizutani, N. Shimada, Y. Ohba, A. Takaoka, N. Yoshida, and T. Taniguchi, Nature 434:772-777, 2005). In contrast, the …


Primary Human Mammary Epithelial Cells Endocytose Hiv-1 And Facilitate Viral Infection Of Cd4+ T Lymphocytes, Stephanie M. Dorosko, Ruth I. Connor Aug 2010

Primary Human Mammary Epithelial Cells Endocytose Hiv-1 And Facilitate Viral Infection Of Cd4+ T Lymphocytes, Stephanie M. Dorosko, Ruth I. Connor

Dartmouth Scholarship

The contribution of mammary epithelial cells (MEC) to human immunodeficiency virus type 1 (HIV-1) in breast milk remains largely unknown. While breast milk contains CD4(+) cells throughout the breast-feeding period, it is not known whether MEC directly support HIV-1 infection or facilitate infection of CD4(+) cells in the breast compartment. This study evaluated primary human MEC for direct infection with HIV-1 and for indirect transfer of infection to CD4(+) target cells. Primary human MEC were isolated and assessed for expression of HIV-1 receptors. MEC were exposed to CCR5-, CXCR4- and dual-tropic strains of HIV-1 and evaluated for viral reverse transcription …


Mononucleosis And Antigen-Driven T Cell Responses Have Different Requirements For Interleukin-2 Signaling In Murine Gammaherpesvirus Infection, Michael Molloy, Weijun Zhang, Edward Usherwood Aug 2010

Mononucleosis And Antigen-Driven T Cell Responses Have Different Requirements For Interleukin-2 Signaling In Murine Gammaherpesvirus Infection, Michael Molloy, Weijun Zhang, Edward Usherwood

Dartmouth Scholarship

Interleukin-2 (IL-2) has been implicated as being necessary for the optimal formation of primary CD8+ T cell responses against various pathogens. Here we have examined the role that IL-2 signaling plays in several aspects of a CD8+ T cell response against murine gammaherpesvirus 68 (MHV-68). Exposure to MHV-68 causes a persistent infection, along with infectious mononucleosis, providing a model for studying these processes in mice. Our study indicates that CD25 is necessary for optimal expansion of the antigen-specific CD8+ T cell response but not for the long-term memory response. Contrastingly, IL-2 signaling through CD25 is absolutely required …


Human Uterine Natural Killer Cells But Not Blood Natural Killer Cells Inhibit Human Immunodeficiency Virus Type 1 Infection By Secretion Of Cxcl12, Teddy F. Mselle, Aexandra L. Howell, Mimi Ghosh, Charles R. Wira, Charles L. Sentman Nov 2009

Human Uterine Natural Killer Cells But Not Blood Natural Killer Cells Inhibit Human Immunodeficiency Virus Type 1 Infection By Secretion Of Cxcl12, Teddy F. Mselle, Aexandra L. Howell, Mimi Ghosh, Charles R. Wira, Charles L. Sentman

Dartmouth Scholarship

Natural killer (NK) cells derived from the human female reproductive tract (FRT) are phenotypically and functionally distinct from those obtained from peripheral blood. Because the FRT is a primary site of human immunodeficiency virus type 1 (HIV-1) infection in women, we determined whether soluble factors secreted by uterine-derived NK (uNK) cells inhibit HIV-1 infection. Clonal populations of uNK cells were activated with interleukin-12 (IL-12) and IL-15, and conditioned media (CM) from these cultures evaluated for their ability to inhibit infection of cells by HIV-1IIIB, HIV-1NL4.3, and HIV-1HC4 (X4-tropic) or HIV-1BaL (R5-tropic) viruses. We found …


Cd80 And Cd86 Control Antiviral Cd8+ T-Cell Function And Immune Surveillance Of Murine Gammaherpesvirus 68, Shinichiro Fuse, Joshua J. Obar, Sarah Bellfy, Erica K. Leung, Weijun Zhang, Edward J. Usherwood Sep 2006

Cd80 And Cd86 Control Antiviral Cd8+ T-Cell Function And Immune Surveillance Of Murine Gammaherpesvirus 68, Shinichiro Fuse, Joshua J. Obar, Sarah Bellfy, Erica K. Leung, Weijun Zhang, Edward J. Usherwood

Dartmouth Scholarship

The interactions between CD80 and CD86 on antigen-presenting cells and CD28 on T cells serve as an important costimulatory signal in the activation of T cells. Although the simplistic two-signal hypothesis has been challenged in recent years by the identification of different costimulators, this classical pathway has been shown to significantly impact antiviral humoral and cellular immune responses. How the CD80/CD86-CD28 pathway affects the control of chronic or latent infections has been less well characterized. In this study, we investigated its role in antiviral immune responses against murine gammaherpesvirus 68 (MHV-68) and immune surveillance using CD80/CD86−/− mice. In the …


Gammaherpesvirus Persistence Alters Key Cd8 T-Cell Memory Characteristics And Enhances Antiviral Protection, Joshua J. Obar, Shinichiro Fuse, Erica K. Leung, Sarah C. Bellfy, Edward J. Usherwood Sep 2006

Gammaherpesvirus Persistence Alters Key Cd8 T-Cell Memory Characteristics And Enhances Antiviral Protection, Joshua J. Obar, Shinichiro Fuse, Erica K. Leung, Sarah C. Bellfy, Edward J. Usherwood

Dartmouth Scholarship

In herpesvirus infections, the virus persists for life but is contained through T-cell-mediated immune surveillance. How this immune surveillance operates is poorly understood. Recent studies of other persistent infections have indicated that virus persistence is associated with functional deficits in the CD8(+) T-cell response. To test whether this is the case in a herpesvirus infection, we used a mutant murine gammaherpesvirus that is defective in its ability to persist in the host. By comparing the immune response to this virus with a revertant virus that can persist, we were able to dissect the changes in the antiviral CD8(+) T-cell response …


The Role Of Cd4 T Cells In The Pathogenesis Of Murine Aids, Wen Li, William R. Green Jun 2006

The Role Of Cd4 T Cells In The Pathogenesis Of Murine Aids, Wen Li, William R. Green

Dartmouth Scholarship

LP-BM5, a retroviral isolate, induces a disease featuring retrovirus-induced immunodeficiency, designated murine AIDS (MAIDS). Many of the features of the LP-BM5-induced syndrome are shared with human immunodeficiency virus-induced disease. For example, CD4 T cells are critical to the development of MAIDS. In vivo depletion of CD4 T cells before LP-BM5 infection rendered genetically susceptible B6 mice MAIDS resistant. Similarly, MAIDS did not develop in B6.nude mice. However, if reconstituted with CD4 T cells, B6.nude mice develop full-blown MAIDS. Our laboratory has shown that the interaction of B and CD4 T cells that is central to MAIDS pathogenesis requires ligation of …


T-Cell Responses To The M3 Immune Evasion Protein Of Murid Gammaherpesvirus 68 Are Partially Protective And Induced With Lytic Antigen Kinetics, Joshua J. Obar, Douglas C. Donovan, Sarah G. Crist, Ondine Silvia, James P. Stewart, Edward J. Usherwood Oct 2004

T-Cell Responses To The M3 Immune Evasion Protein Of Murid Gammaherpesvirus 68 Are Partially Protective And Induced With Lytic Antigen Kinetics, Joshua J. Obar, Douglas C. Donovan, Sarah G. Crist, Ondine Silvia, James P. Stewart, Edward J. Usherwood

Dartmouth Scholarship

DNA vaccination with the M3 gene, encoding an immune evasion molecule expressed during both the acute lytic and persistent phases of murid gammaherpesvirus 68 infection, yielded a significantly lower titer of virus in the lung than controls. The protection seen was dependent on T cells, and we mapped an epitope recognized by CD8 T cells. The immune response to this epitope follows the same kinetics as lytic cycle antigens, despite the fact that this gene is expressed in both lytic and persistent stages of infection. This has important implications for our understanding of T-cell responses to putative latency-associated gammaherpesvirus proteins …


Cd40-Associated Traf 6 Signaling Is Required For Disease Induction In A Retrovirus-Induced Murine Immunodeficiency, Kathy A. Green, Cory L. Ahonen, W. James Cook, William R. Green Jan 2004

Cd40-Associated Traf 6 Signaling Is Required For Disease Induction In A Retrovirus-Induced Murine Immunodeficiency, Kathy A. Green, Cory L. Ahonen, W. James Cook, William R. Green

Dartmouth Scholarship

LP-BM5 retrovirus-infected C57BL/6 mice develop splenomegaly, lymphadenopathy, hypergammaglobulinemia, and immunodeficiency; thus, this disease has been named mouse AIDS. In this syndrome, CD154/CD40 interactions are required for but do not mediate disease by upregulation of CD80 or CD86. We report here that there is nonetheless a necessity for CD40 signaling competence, specifically an intact tumor necrosis factor receptor-associated factor 6 (TRAF 6) binding site.


The Cd154/Cd40 Interaction Required For Retrovirus-Induced Murine Immunodeficiency Syndrome Is Not Mediated By Upregulation Of The Cd80/Cd86 Costimulatory Molecules, Kathy A. Green, W. James Cook, Arlene H. Sharpe, William R. Green Nov 2002

The Cd154/Cd40 Interaction Required For Retrovirus-Induced Murine Immunodeficiency Syndrome Is Not Mediated By Upregulation Of The Cd80/Cd86 Costimulatory Molecules, Kathy A. Green, W. James Cook, Arlene H. Sharpe, William R. Green

Dartmouth Scholarship

C57BL/6 (B6) mice infected with LP-BM5 retroviruses develop disease, including an immunodeficiency similar to AIDS. This disease, murine AIDS (MAIDS), is inhibited by in vivo anti-CD154 monoclonal antibody treatment. The similar levels of insusceptibility of CD40−/− and CD154−/− B6 mice indicate that CD154/CD40 molecular interactions are required for MAIDS. CD4+ T and B cells, respectively, provide the CD154 and CD40 expression needed for MAIDS induction. Here, the required CD154/CD40 interaction is shown to be independent of CD80 and CD86 expression: CD80/CD86−/− B6 mice develop MAIDS after LP-BM5 infection.


Activation Of The Human Thymidine Kinase (Tk) Promoter By Simian Virus 40 Large T Antigen Requires Both The T Antigen Prb Family-Binding Domain And Tk Promoter Sequences Resembling E2f-Binding Sites., Michelle M. Anderson, Jun Chen, Charles N. Cole, Susan E. Conrad Sep 1996

Activation Of The Human Thymidine Kinase (Tk) Promoter By Simian Virus 40 Large T Antigen Requires Both The T Antigen Prb Family-Binding Domain And Tk Promoter Sequences Resembling E2f-Binding Sites., Michelle M. Anderson, Jun Chen, Charles N. Cole, Susan E. Conrad

Dartmouth Scholarship

Infection of quiescent cells with the DNA tumor virus simian virus 40 induces expression of the cellular thymidine kinase (TK) gene a minimum of 10- to 20-fold, and this induction depends upon the viral protein large T antigen (T-Ag). To define both human TK promoter elements and T-Ag functional domains required for transcriptional induction, we have established a system in which stable Rat-1 transfectants harboring TK promoter-luciferase hybrid genes are infected with recombinant adenoviruses expressing either wild-type or mutant forms of T-Ag and luciferase expression is measured as an indicator of promoter activity. The results show that (i) a 135-bp …


Antibody To The Ligand For Cd40 (Gp39) Inhibits Murine Aids-Associated Splenomegaly, Hypergammaglobulinemia, And Immunodeficiency In Disease-Susceptible C57bl/6 Mice., Kathy A. Green, Karen M. Crassi, Jon D. Laman, Arjan Schoneveld, Rendall R. Strawbridge, Teresa M. Foy, Randolph J. Noelle, William R. Green Apr 1996

Antibody To The Ligand For Cd40 (Gp39) Inhibits Murine Aids-Associated Splenomegaly, Hypergammaglobulinemia, And Immunodeficiency In Disease-Susceptible C57bl/6 Mice., Kathy A. Green, Karen M. Crassi, Jon D. Laman, Arjan Schoneveld, Rendall R. Strawbridge, Teresa M. Foy, Randolph J. Noelle, William R. Green

Dartmouth Scholarship

Infection of genetically susceptible C57BL/6 mice with the LP-BM5 isolate of murine retroviruses cause profound splenomegaly, hypergammaglobulinemia, lymphadenopathy, and an immunodeficiency syndrome which includes the development of terminal B-cell lymphomas. Because many of these and the other manifestations of LP-BM5 virus-induced disease are similar to those seen in AIDS, this syndrome has been named murine AIDS, or MAIDS. Previous reports have shown that the onset of MAIDS depends on the presence of both CD41 T cells and B cells and have suggested that CD41 T-cell-B-cell interactions are important to disease pathogenesis. Here, we assessed the possibility that interactions between CD40 …


A Tef-1-Independent Mechanism For Activation Of The Simian Virus 40 (Sv40) Late Promoter By Mutant Sv40 Large T Antigens., Paul Casaz, Phillip W. Rice, Charles N. Cole, Ulla Hansen Jun 1995

A Tef-1-Independent Mechanism For Activation Of The Simian Virus 40 (Sv40) Late Promoter By Mutant Sv40 Large T Antigens., Paul Casaz, Phillip W. Rice, Charles N. Cole, Ulla Hansen

Dartmouth Scholarship

Simian virus 40 (SV40) large tumor antigen (T antigen) stimulates the activity of the SV40 late promoter and a number of cellular and other viral promoters. We have characterized the ability of T antigens with mutations in the DNA-binding domain and within the N-terminal 85 residues to activate the SV40 late promoter. T antigens lacking both nonspecific and sequence-specific DNA-binding activities were able to induce the late promoter. Mutations within the N-terminal 85 residues of T antigen diminished activation by less than twofold. Activation by wild-type and most of the mutant T antigens required intact binding sites for the cellular …


A Novel Translational Regulation Function For The Simian Virus 40 Large-T Antigen Gene., Prithi Rajan, Sathyamagalam Swaminathan, Jiyue Zhu, Charles N. Cole Feb 1995

A Novel Translational Regulation Function For The Simian Virus 40 Large-T Antigen Gene., Prithi Rajan, Sathyamagalam Swaminathan, Jiyue Zhu, Charles N. Cole

Dartmouth Scholarship

Cells use the interferon-induced, double-stranded-RNA-dependent protein kinase PKR as a defense against virus infections. Upon activation, PKR phosphorylates and thereby inactivates the protein synthesis initiation factor eIF-2, resulting in the cessation of protein synthesis. Viruses have evolved various strategies to counteract this cellular defense. In this paper, we show that simian virus 40 (SV40) large-T antigen can antagonize the translational inhibitory effect resulting from the activation of PKR in virus-infected cells. Unlike the situation with other virus-host cell interactions, SV40 large-T antigen does not block the activation of PKR, suggesting that SV40 counteracts the cellular antiviral response mediated by PKR …


Adoptive Transfer Of Polyclonal And Cloned Cytolytic T Lymphocytes (Ctl) Specific For Mouse Aids-Associated Tumors Is Effective In Preserving Ctl Responses: A Measure Of Protection Against Lp-Bm5 Retrovirus-Induced Immunodeficiency., William R. Green, Kathy A. Green, Karen M. Crassi Jul 1994

Adoptive Transfer Of Polyclonal And Cloned Cytolytic T Lymphocytes (Ctl) Specific For Mouse Aids-Associated Tumors Is Effective In Preserving Ctl Responses: A Measure Of Protection Against Lp-Bm5 Retrovirus-Induced Immunodeficiency., William R. Green, Kathy A. Green, Karen M. Crassi

Dartmouth Scholarship

Cytolytic T lymphocytes (CTL) can be raised against C57BL/6 B-cell lymphomas from mice with LP-BM5 murine leukemia virus-induced AIDS (MAIDS). Adoptive transfer of polyclonal anti-MAIDS tumor CTL or two CTL clones specific for the B6-1710 MAIDS lymphoma caused preservation of major histocompatibility complex-restricted and allogeneic CTL responses, which may be interpreted as indices of protection from LP-BM5 murine leukemia virus-induced immunodeficiency.


Molecular Cloning Of Infectious Ecotropic Murine Leukemia Virus Ak7 From An Emv-14-Positive Akxl-5 Mouse And The Resistance Of Ak7 To Recognition By Cytotoxic T Lymphocytes., Hillary D. White, William R. Green, Nuria R. Giné Aug 1993

Molecular Cloning Of Infectious Ecotropic Murine Leukemia Virus Ak7 From An Emv-14-Positive Akxl-5 Mouse And The Resistance Of Ak7 To Recognition By Cytotoxic T Lymphocytes., Hillary D. White, William R. Green, Nuria R. Giné

Dartmouth Scholarship

The AKXL-5 recombinant inbred mouse strain is positive for the endogenous ecotropic murine leukemia virus emv-14, the only emv present in its germ line. emv-14 is of particular interest because spleen cells expressing emv-14 virus escape recognition by anti-AKR/Gross virus-specific cytotoxic T lymphocytes. We report here the isolation and characterization of a replication-competent emv clone, pAK7, derived from an AKXL-5 mouse. This clone is novel in that it encodes a variant ecotropic murine leukemia virus that, when expressed in SC.Kb target cells, fails to be recognized efficiently by anti-AKR/Gross virus cytotoxic T lymphocytes. The pAK7 clone can therefore be used …


Cytolytic T Lymphocytes Specific For Tumors And Infected Cells From Mice With A Retrovirus-Induced Immunodeficiency Syndrome., Jennifer G. Erbe, Kathy A. Green, Karen M. Crassi, Herbert C. Morse, W R. Green May 1992

Cytolytic T Lymphocytes Specific For Tumors And Infected Cells From Mice With A Retrovirus-Induced Immunodeficiency Syndrome., Jennifer G. Erbe, Kathy A. Green, Karen M. Crassi, Herbert C. Morse, W R. Green

Dartmouth Scholarship

LP-BM5 retrovirus complex-infected C57BL/6 mice develop immunodeficiency, somewhat analogous to AIDS, termed murine AIDS (MAIDS). After secondary stimulation with syngeneic B-cell lymphomas from LP-BM5-infected mice, C57BL/6 mice produced vigorous CD8+ cytotoxic T lymphocytes specific for MAIDS-associated tumors. An anti-LP-BM5 specificity was suggested because spleen and lymph node cells from LP-BM5-infected mice served as target cells in competition assays, and cells from LP-BM5, but not ecotropic, virus-infected mice functioned as secondary in vitro stimulators to generate cytotoxic T lymphocytes to MAIDS tumors.


The Growth Of Simian Virus 40 (Sv40) Host Range/Adenovirus Helper Function Mutants In An African Green Monkey Cell Line That Constitutively Expresses The Sv40 Agnoprotein., Terryl P. Stacy, Michele Chamberlain, Susan Carswell, Charles N. Cole Jul 1990

The Growth Of Simian Virus 40 (Sv40) Host Range/Adenovirus Helper Function Mutants In An African Green Monkey Cell Line That Constitutively Expresses The Sv40 Agnoprotein., Terryl P. Stacy, Michele Chamberlain, Susan Carswell, Charles N. Cole

Dartmouth Scholarship

The simian virus 40 T-antigen carboxy-terminal mutants, dlA2459 and dlA2475, are cell line and temperature dependent for growth and plaque formation in monkey kidney cells. Although these mutants did form plaques on BSC-1 cells at 37 degrees C, they were about fivefold less efficient for plaque formation than wild-type simian virus 40. These mutants did not grow in CV-1 cells and did not synthesize agnoprotein in those cells. CV-1 cells which constitutively express the agnoprotein were permissive for mutant plaque formation. However, late mRNAs, virion proteins, and progeny virion yields did not accumulate to wild-type levels during mutant infection of …


Mechanism Of Escape Of Endogenous Murine Leukemia Virus Emv-14 From Recognition By Anti-Akr/Gross Virus Cytolytic T Lymphocytes., Hillary D. White, Michael D. Robbins, William R. Green Jun 1990

Mechanism Of Escape Of Endogenous Murine Leukemia Virus Emv-14 From Recognition By Anti-Akr/Gross Virus Cytolytic T Lymphocytes., Hillary D. White, Michael D. Robbins, William R. Green

Dartmouth Scholarship

It was previously shown that spleen cells from endogenous ecotropic murine leukemia virus emv-14+ AKXL-5 mice fail to stimulate an anti-AKR/Gross virus cytolytic T-lymphocyte (CTL) response in a mixed lymphocyte culture with primed C57BL/6 responder spleen cells, whereas spleen cells from AKXL strains carrying the very similar emv-11 provirus do stimulate a response (Green and Graziano, Immunogenetics 23:106-110, 1986). We wished to determine whether the lack of response with AKXL-5 spleen cells was at the level of recognition between effector cell and target cell and whether the relevant mutation was within the emv-14 provirus. It is shown here that EMV-negative …