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1.
J Virol ; 97(10): e0093023, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37792000

RESUMO

IMPORTANCE: Mouse models of viral infection play an especially large role in virology. In 1960, a mouse virus, lactate dehydrogenase-elevating virus (LDV), was discovered and found to have the peculiar ability to evade clearance by the immune system, enabling it to persistently infect an individual mouse for its entire lifespan without causing overt disease. However, researchers were unable to grow LDV in culture, ultimately resulting in the demise of this system as a model of failed immunity. We solve this problem by identifying the cell-surface molecule CD163 as the critical missing component in cell-culture systems, enabling the growth of LDV in immortalized cell lines for the first time. This advance creates abundant opportunities for further characterizing LDV in order to study both failed immunity and the family of viruses to which LDV belongs, Arteriviridae (aka, arteriviruses).


Assuntos
Antígenos CD , Antígenos de Diferenciação Mielomonocítica , Técnicas de Cultura de Células , Expressão Ectópica do Gene , Vírus Elevador do Lactato Desidrogenase , Receptores de Superfície Celular , Animais , Camundongos , Antígenos CD/genética , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/genética , Antígenos de Diferenciação Mielomonocítica/metabolismo , Linhagem Celular/virologia , Vírus Elevador do Lactato Desidrogenase/genética , Vírus Elevador do Lactato Desidrogenase/crescimento & desenvolvimento , Vírus Elevador do Lactato Desidrogenase/imunologia , Vírus Elevador do Lactato Desidrogenase/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Fatores de Tempo
2.
Toxicol Pathol ; 50(3): 390-396, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35450478

RESUMO

Following implantation of patient-derived xenograft (PDX) breast carcinomas from three separate individuals, 33/51 female NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice presented with progressive, unilateral to bilateral, ascending hindlimb paresis to paralysis. Mice were mildly dehydrated, in thin to poor body condition, with reduced to absent hindlimb withdrawal reflex and deep pain sensation. Microscopically, there was variable axonal swelling, vacuolation, and dilation of myelin sheaths within the ventral spinal cord and spinal nerve roots of the thoracolumbar and sacral spinal cord, as well as within corresponding sciatic nerves. Results of PCR screening of PDX samples obtained at necropsy and pooled environmental swabs from the racks housing affected animals were positive for lactate dehydrogenase-elevating virus (LDV). LDV is transmitted through animal-animal contact or commonly as a contaminant of biologic materials of mouse origin. Infection is associated with progressive degenerative myelopathy and neuropathy in strains of mice harboring endogenous retrovirus (AKR, C58), or in immunosuppressed strains (NOD-SCID, Foxn1nu), and can interfere with normal immune responses and alter engraftment and growth of xenograft tumors in immunosuppressed mice. This is the first reported series of LDV-induced poliomyelitis in NSG mice and should be recognized as a potentially significant confounder to biomedical studies utilizing immunodeficient xenograft models.


Assuntos
Vírus Elevador do Lactato Desidrogenase , Imunodeficiência Combinada Severa , Doenças da Medula Espinal , Animais , Proteína Quinase Ativada por DNA , Proteínas de Ligação a DNA , Modelos Animais de Doenças , Feminino , Humanos , Subunidade gama Comum de Receptores de Interleucina , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID
3.
Int J Mol Sci ; 22(16)2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34445732

RESUMO

Infection with viruses, such as the lactate dehydrogenase-elevating virus (LDV), is known to trigger the onset of autoimmune anemia through the enhancement of the phagocytosis of autoantibody-opsonized erythrocytes by activated macrophages. Type I interferon receptor-deficient mice show enhanced anemia, which suggests a protective effect of these cytokines, partly through the control of type II interferon production. The development of anemia requires the expression of Fcγ receptors (FcγR) I, III, and IV. Whereas LDV infection decreases FcγR III expression, it enhances FcγR I and IV expression in wild-type animals. The LDV-associated increase in the expression of FcγR I and IV is largely reduced in type I interferon receptor-deficient mice, through both type II interferon-dependent and -independent mechanisms. Thus, the regulation of the expression of FcγR I and IV, but not III, by interferons may partly explain the exacerbating effect of LDV infection on anemia that results from the enhanced phagocytosis of IgG autoantibody-opsonized erythrocytes.


Assuntos
Anemia Hemolítica Autoimune/imunologia , Infecções por Arterivirus/imunologia , Interferons/metabolismo , Vírus Elevador do Lactato Desidrogenase/imunologia , Receptores de IgG/metabolismo , Anemia Hemolítica Autoimune/virologia , Animais , Infecções por Arterivirus/virologia , Interações Hospedeiro-Patógeno , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fagocitose
4.
mBio ; 11(2)2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32265335

RESUMO

Coinfections shape immunity and influence the development of inflammatory diseases, resulting in detrimental or beneficial outcome. Coinfections with concurrent Plasmodium species can alter malaria clinical evolution, and malaria infection itself can modulate autoimmune reactions. Yet, the underlying mechanisms remain ill defined. Here, we demonstrate that the protective effects of some rodent malaria strains on T cell-mediated inflammatory pathologies are due to an RNA virus cohosted in malaria-parasitized blood. We show that live and extracts of blood parasitized by Plasmodium berghei K173 or Plasmodium yoelii 17X YM, protect against P. berghei ANKA-induced experimental cerebral malaria (ECM) and myelin oligodendrocyte glycoprotein (MOG)/complete Freund's adjuvant (CFA)-induced experimental autoimmune encephalomyelitis (EAE), and that protection is associated with a strong type I interferon (IFN-I) signature. We detected the presence of the RNA virus lactate dehydrogenase-elevating virus (LDV) in the protective Plasmodium stabilates and we established that LDV infection alone was necessary and sufficient to recapitulate the protective effects on ECM and EAE. In ECM, protection resulted from an IFN-I-mediated reduction in the abundance of splenic conventional dendritic cell and impairment of their ability to produce interleukin (IL)-12p70, leading to a decrease in pathogenic CD4+ Th1 responses. In EAE, LDV infection induced IFN-I-mediated abrogation of IL-23, thereby preventing the differentiation of granulocyte-macrophage colony-stimulating factor (GM-CSF)-producing encephalitogenic CD4+ T cells. Our work identifies a virus cohosted in several Plasmodium stabilates across the community and deciphers its major consequences on the host immune system. More generally, our data emphasize the importance of considering contemporaneous infections for the understanding of malaria-associated and autoimmune diseases.IMPORTANCE Any infection modifies the host immune status, potentially ameliorating or aggravating the pathophysiology of a simultaneous inflammatory condition. In the course of investigating how malaria infection modulates the severity of contemporaneous inflammatory diseases, we identified a nonpathogenic mouse virus in stabilates of two widely used rodent parasite lines: Plasmodium berghei K173 and Plasmodium yoelii 17X YM. We established that the protective effects of these Plasmodium lines on cerebral malaria and multiple sclerosis are exclusively due to this virus. The virus induces a massive type I interferon (IFN-I) response and causes quantitative and qualitative defects in the ability of dendritic cells to promote pathogenic T cell responses. Beyond revealing a possible confounding factor in rodent malaria models, our work uncovers some bases by which a seemingly innocuous viral (co)infection profoundly changes the immunopathophysiology of inflammatory diseases.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Inflamação/imunologia , Interferon Tipo I/imunologia , Vírus Elevador do Lactato Desidrogenase/imunologia , Malária Cerebral/imunologia , Animais , Coinfecção/imunologia , Coinfecção/parasitologia , Coinfecção/virologia , Citocinas/imunologia , Células Dendríticas/imunologia , Inflamação/fisiopatologia , Interferon gama/imunologia , Malária Cerebral/sangue , Malária Cerebral/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Plasmodium berghei , Plasmodium yoelii , Baço/citologia , Baço/imunologia
5.
J Am Assoc Lab Anim Sci ; 59(3): 328-333, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32079556

RESUMO

Lactate dehydrogenase elevating virus (LDV) continues to be one of the most common contaminants of cells and cell byproducts. As such, many institutions require that tumor cell lines, blood products, and products derived or passaged in rodent tissues are free of LDV as well as other pathogens that are on institutional exclusion lists prior to their use in rodents. LDV is difficult to detect by using a live-animal sentinel health monitoring program because the virus does not reliably pass to sentinel animals. After switching to an exhaust air dust health monitoring system, our animal resources center was able to detect a presumably long-standing LDV infection in a mouse colony. This health monitoring system uses IVC rack exhaust air dust collection media in conjunction with PCR analysis. Ultimately, the source of the contamination was identified as multiple LDV-positive patient-derived xenografts and multiple LDV-positive breeding animals. This case study is the first to demonstrate the use of environmental PCR testing as a method for detecting LDV infection in a mouse vivarium.


Assuntos
Infecções por Arterivirus/veterinária , Microbiologia Ambiental , Abrigo para Animais , Vírus Elevador do Lactato Desidrogenase/isolamento & purificação , Camundongos , Doenças dos Roedores/virologia , Animais , Infecções por Arterivirus/virologia , Linhagem Celular Tumoral/virologia , Poeira , Xenoenxertos , Humanos , Reação em Cadeia da Polimerase , Células Tumorais Cultivadas/virologia
6.
Int J Radiat Biol ; 92(10): 577-82, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27548028

RESUMO

PURPOSE: Cancer initialization can be explained as a result of parasitic virus energy consumption leading to randomized genome chemical bonding. MATERIALS AND METHODS: Analysis of experimental data on cell-mediated immunity (CMI) containing about 12,000 cases of healthy humans, cancer patients and patients with precancerous cervical lesions disclosed that the specific cancer and the non-specific lactate dehydrogenase-elevating (LDH) virus antigen elicit similar responses. The specific antigen is effective only in cancer type of its origin but the non-specific antigen in all examined cancers. CMI results of CIN patients display both healthy and cancer state. The ribonucleic acid (RNA) of the LDH virus parasitizing on energy reduces the ratio of coherent/random oscillations. Decreased effect of coherent cellular electromagnetic field on bonding electrons in biological macromolecules leads to elevating probability of random genome reactions. RESULTS: Overlapping of wave functions in biological macromolecules depends on energy of the cellular electromagnetic field which supplies energy to bonding electrons for selective chemical bonds. CMI responses of cancer and LDH virus antigens in all examined healthy, precancerous and cancer cases point to energy mechanism in cancer initiation. CONCLUSIONS: Dependence of the rate of biochemical reactions on biological electromagnetic field explains yet unknown mechanism of genome mutation.


Assuntos
Campos Eletromagnéticos , Mutação/genética , Neoplasias/genética , Neoplasias/imunologia , Oncogenes/genética , Oncogenes/imunologia , Simulação por Computador , Humanos , Vírus Elevador do Lactato Desidrogenase/fisiologia , Modelos Químicos , Modelos Genéticos , Modelos Imunológicos , Mutação/efeitos da radiação , Neoplasias/virologia , Oncogenes/efeitos da radiação , Linfócitos T/imunologia , Linfócitos T/efeitos da radiação , Linfócitos T/virologia
7.
J Immunol ; 195(9): 4171-5, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26385523

RESUMO

IgM anti-mouse platelet autoantibodies cause thrombocytopenia by mediating uptake of opsonized thrombocytes, whereas IgM anti-erythrocyte autoantibodies induce anemia through a phagocytosis-independent cell destruction. In this article, we show that infection with lactate dehydrogenase-elevating virus, a benign mouse arterivirus, exacerbates the pathogenicity of IgM anti-platelet, but not anti-erythrocyte autoantibodies. To define the role of Fcα/µ receptor (Fcα/µR) in IgM-mediated thrombocytopenia and anemia, we generated mice deficient for this receptor. These animals were resistant to IgM autoantibody-mediated thrombocytopenia, but not anemia. However, the lactate dehydrogenase-elevating virus-induced exacerbation of thrombocytopenia was not associated with enhanced Fcα/µR expression on macrophages. These results indicate that Fcα/µR is required for the pathogenicity of IgM anti-platelet autoantibodies but is not sufficient to explain the full extent of the disease in virally infected animals.


Assuntos
Autoanticorpos/imunologia , Plaquetas/imunologia , Eritrócitos/imunologia , Imunoglobulina M/imunologia , Receptores Fc/fisiologia , Animais , Infecções por Arterivirus/imunologia , Vírus Elevador do Lactato Desidrogenase , Camundongos , Camundongos Endogâmicos C57BL , Trombocitopenia/etiologia
8.
Electromagn Biol Med ; 34(2): 151-5, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26098528

RESUMO

Human and animal diseases are brought about by pathological alterations of production, composition, and conformation of macromolecules and structures in cells. Additional contributing factors include changes in physiological states caused by disturbances of energy supply, energy transduction, energy dissipation in moving or oscillating parts, and parasitic energy consumption. Disturbances of energy states may endanger existence of the system. The cell-mediated immunity (CMI) response of T lymphocytes correlating with their adherence properties was examined using antigen prepared from the serum of inbred laboratory mice strain C3H H(2k) infected with lactate dehydrogenase elevating (LDH) virus. LDH virus is a parasite on the cellular energy system. Significant CMI response was elicited in T lymphocytes prepared from the blood of patients with cancer of different phenotypes, acute myocardial infarctions, schizophrenia, and recurrent spontaneous abortions in early pregnancy from unknown reasons. The CMI response is assumed to monitor transferred information about decreased levels of energy states and decoherence in the cells caused by mitochondrial malfunction, parasitic consumption, production of lactate, and possibly other disturbances. The LDH virus infection or similar pathological processes caused by different agents might be connected with the diseases and monitored by the examined CMI response. A large amount of mitoses with chromosome defects in aborted fetuses suggest increased mutability of genomes caused by defective energy states.


Assuntos
Doença , Metabolismo Energético , Animais , Sobrevivência Celular , Feminino , Humanos , Imunidade Celular , Vírus Elevador do Lactato Desidrogenase/fisiologia , Camundongos , Gravidez , Linfócitos T/imunologia
9.
J Gen Virol ; 95(Pt 7): 1504-1509, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24739273

RESUMO

Although many cells undergo transformation, few actually develop into tumours, due to successful mechanisms of immunosurveillance. To investigate whether an infectious agent may play a role in this process, the growth of a plasmacytoma was investigated in mice infected by lactate dehydrogenase-elevating virus. Acutely infected animals were significantly protected against tumour development. The mechanisms responsible for this protection were analysed in mice deficient for relevant immune cells or molecules and after in vivo cell depletion. This protection by viral infection correlated with NK cell activation and with IFN-γ production. It might also be related to activation of NK/T-cells, although this remains to be proven formally. Therefore, our results indicated that infections with benign micro-organisms may protect the host against cancer development, through non-specific stimulation of the host's innate immune system and especially of NK cells.


Assuntos
Células Matadoras Naturais/imunologia , Vírus Elevador do Lactato Desidrogenase/imunologia , Vírus Oncolíticos/imunologia , Plasmocitoma/imunologia , Plasmocitoma/prevenção & controle , Animais , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout
10.
J Am Assoc Lab Anim Sci ; 52(3): 253-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23849407

RESUMO

Commercially available diagnostic tools for the detection of lactate dehydrogenase elevating virus (LDV) infection have been restricted to measurement of serum lactate dehydrogenase (LDH) activity levels and detection of the viral genome by RT-PCR assays. Serologic diagnosis of LDV infection has not been widely adopted due to the belief that the formation of antigen-antibody complexes and B-cell polyclonal activation may confound interpretation of results. In the current study, we inoculated BALB/c, C57BL/6, and Swiss Webster mice with LDV to compare the diagnostic reliability of a commercially available multiplex fluorescent immunoassay for the detection of antiLDV antibodies with that of the LDH enzyme assay. The serologic assay was vastly more sensitive and specific than was the LDH enzyme assay. Moreover, the serologic assay detected antiviral antibodies throughout the 3-mo time course of this study. These results suggest that antigen-antibody complex formation and polyclonal B-cell activation had little effect on assay performance.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Arterivirus/veterinária , Imunoensaio/métodos , Vírus Elevador do Lactato Desidrogenase/isolamento & purificação , Doenças dos Roedores/virologia , Animais , Animais não Endogâmicos , Complexo Antígeno-Anticorpo/imunologia , Infecções por Arterivirus/virologia , Linfócitos B/imunologia , Ensaios Enzimáticos/métodos , Feminino , L-Lactato Desidrogenase/análise , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Reprodutibilidade dos Testes
11.
Int Immunopharmacol ; 15(3): 544-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23391715

RESUMO

Lactate dehydrogenase-elevating virus (LDV) is an apparently innocuous and persistent virus that can modify mouse immune reactions. We have shown that LDV-infected mice immunized with human growth hormone (hGH) showed a deep modification of the specificity of the anti-hGH antibodies (Ab) in CBA/Ht mice but not BALB/c animals. The aim of this work was to extend the previous observations to another mouse strain, C57BL/6, as well as to an antigen unrelated to hGH, ovalbumin (OVA), and to explore at the same time the production of various cytokines at serum and cellular levels. The amount of Ab directed to hGH or OVA native antigenic determinants versus the concentration of Ab to cryptic epitopes was evaluated by ELISA competition experiments. Results indicated that LDV infection affected Ab specificity solely in CBA/Ht mice. In CBA/Ht the virus infection was associated with a reduction of the Ab titers to hGH native epitopes and with a decrease of IL-13 and IL-17 serum levels, but Ab to native OVA epitopes were increased with a simultaneous increase of IL-17. Accordingly, only lymph node cells from infected CBA/Ht mice immunized with OVA were found to produce INF-γ, IL-13 and IL-17. Thus, a correlation of cytokine production with a change in Ab specificity after a viral infection was found, although this phenomenon was restricted to a given antigen and to the genetic background of immunized animals. These observations suggest that an apparent harmless virus can affect some immunological mechanisms, which could lead, for example, to inflammatory or autoimmune disorders.


Assuntos
Anticorpos Antivirais/imunologia , Especificidade de Anticorpos , Infecções por Arterivirus/imunologia , Citocinas/imunologia , Epitopos Imunodominantes/imunologia , Vírus Elevador do Lactato Desidrogenase/imunologia , Animais , Anticorpos Antivirais/sangue , Hormônio do Crescimento/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Ovalbumina/imunologia , Especificidade da Espécie
12.
J Virol ; 86(22): 12414-6, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22933286

RESUMO

Previously we demonstrated that antibody-mediated thrombocytopenia is strongly enhanced by lactate dehydrogenase-elevating virus (LDV) infection. Here we report that mice infected with LDV develop a moderate thrombocytopenia, even in the absence of immunoglobulins or Fc receptors. A similar decrease of platelet counts was observed after mouse hepatitis virus infection. LDV-induced type I interferon-independent thrombocytopenia was partly suppressed by treatment with clodronate-containing liposomes. Therefore, we conclude that the thrombocytopenia results from increased phagocytosis of nonopsonized platelets by macrophages.


Assuntos
Infecções por Arterivirus/virologia , Vírus Elevador do Lactato Desidrogenase/metabolismo , Trombocitopenia/imunologia , Animais , Plaquetas/virologia , Ácido Clodrônico/farmacologia , Feminino , Imunoglobulinas/metabolismo , Lipossomos/química , Macrófagos/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Fagocitose , Contagem de Plaquetas , Receptores Fc/metabolismo , Replicação Viral
13.
J Immunol ; 189(5): 2521-9, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22821964

RESUMO

The immune system is tasked with defending against a myriad of microbial infections, and its response to a given infectious microbe may be strongly influenced by coinfection with another microbe. It was shown that infection of mice with lactate dehydrogenase-elevating virus (LDV) impairs early adaptive immune responses to Friend virus (FV) coinfection. To investigate the mechanism of this impairment, we examined LDV-induced innate immune responses and found LDV-specific induction of IFN-α and IFN-γ. LDV-induced IFN-α had little effect on FV infection or immune responses, but unexpectedly, LDV-induced IFN-γ production dampened Th1 adaptive immune responses and enhanced FV infection. Two distinct effects were identified. First, LDV-induced IFN-γ signaling indirectly modulated FV-specific CD8+ T cell responses. Second, intrinsic IFN-γ signaling in B cells promoted polyclonal B cell activation and enhanced early FV infection, despite promotion of germinal center formation and neutralizing Ab production. Results from this model reveal that IFN-γ production can have detrimental effects on early adaptive immune responses and virus control.


Assuntos
Imunidade Adaptativa , Regulação para Baixo/imunologia , Interferon gama/fisiologia , Vírus da Leucemia Murina/imunologia , Infecções por Retroviridae/imunologia , Imunidade Adaptativa/genética , Animais , Modelos Animais de Doenças , Regulação para Baixo/genética , Feminino , Vírus da Leucemia Murina de Friend/imunologia , Vírus da Leucemia Murina de Friend/patogenicidade , Interferon gama/deficiência , Interferon gama/genética , Vírus Elevador do Lactato Desidrogenase/imunologia , Vírus Elevador do Lactato Desidrogenase/patogenicidade , Vírus da Leucemia Murina/patogenicidade , Leucemia Experimental/genética , Leucemia Experimental/imunologia , Leucemia Experimental/virologia , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos A , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Mutantes , Infecções por Retroviridae/genética , Infecções por Retroviridae/patologia , Vírus Formadores de Foco no Baço/imunologia , Vírus Formadores de Foco no Baço/patogenicidade , Infecções Tumorais por Vírus/genética , Infecções Tumorais por Vírus/imunologia , Infecções Tumorais por Vírus/virologia
14.
J Gen Virol ; 93(Pt 1): 106-112, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21940410

RESUMO

Lactate dehydrogenase-elevating virus (LDV) exacerbates mouse susceptibility to endotoxin shock through enhanced tumour necrosis factor (TNF) production by macrophages exposed to lipopolysaccharide (LPS). However, the in vivo enhancement of TNF production in response to LPS induced by the virus largely exceeds that found in vitro with cells derived from infected animals. Infection was followed by a moderate increase of Toll-like receptor (TLR)-4/MD2, but not of membrane CD14 expression on peritoneal macrophages. Peritoneal macrophages from LDV-infected mice unresponsive to type I interferons (IFNs) did not show enhanced expression of TLR-4/MD2 nor of CD14, and did not produce more TNF in response to LPS than cells from infected normal counterparts, although the in vivo response of these animals to LPS was strongly enhanced. In contrast, the virus triggered a sharp increase of soluble CD14 and of LPS-binding protein serum levels in normal mice. However, production of these LPS soluble receptors was similar in LDV-infected type I IFN-receptor deficient mice and in their normal counterparts. Moreover, serum of LDV-infected mice that contained these soluble receptors had little effect if any on cell response to LPS. These results suggest that enhanced response of LDV-infected mice to LPS results mostly from mechanisms independent of LPS receptor expression.


Assuntos
Infecções por Arterivirus/veterinária , Vírus Elevador do Lactato Desidrogenase/fisiologia , Receptores de Lipopolissacarídeos/genética , Doenças dos Roedores/genética , Doenças dos Roedores/virologia , Proteínas de Fase Aguda/genética , Proteínas de Fase Aguda/imunologia , Animais , Infecções por Arterivirus/genética , Infecções por Arterivirus/imunologia , Infecções por Arterivirus/virologia , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Células Cultivadas , Regulação para Baixo , Feminino , Vírus Elevador do Lactato Desidrogenase/imunologia , Receptores de Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/imunologia , Antígeno 96 de Linfócito/genética , Antígeno 96 de Linfócito/imunologia , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/virologia , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Doenças dos Roedores/imunologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
15.
J Virol Methods ; 173(2): 266-70, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21354210

RESUMO

Lactate dehydrogenase-elevating virus (LDV) can infect transplantable mouse tumors or xenograft tumors in mice through LDV-contaminated mouse biological materials, such as Matrigel, or through mice infected with LDV. LDV infects specifically mouse macrophages and alters immune system and tumor phenotype. The traditional approaches to remove LDV from tumor cells, by transplanting tumors into rats or culturing tumor cells in vitro, are inefficient, labor-intensive and time-consuming. Furthermore, these approaches are not feasible for primary tumor cells that cannot survive tissue culture conditions or that may change phenotype in rats. This study reports that fluorescence-activated cell sorting (FACS) is a simple and efficient approach for purifying living primary human breast tumor cells from LDV(+) mouse stromal cells, which can be completed in a few hours. When purified from Matrigel contaminated LDV(+) tumors, sorted human breast tumor cells, as well as tumors grown from sorted cells, were shown to be LDV-free, as tested by PCR. The results demonstrate that cell sorting is effective, much faster and less likely to alter tumor cell phenotype than traditional methods for removing LDV from xenograft models. This approach may also be used to remove other rodent-specific viruses from models derived from distinct tissues or species with sortable markers, where virus does not replicate in the cells to be purified.


Assuntos
Neoplasias da Mama/virologia , Vírus Elevador do Lactato Desidrogenase/isolamento & purificação , Transplante Heterólogo , Animais , Técnicas de Cultura de Células/métodos , Feminino , Citometria de Fluxo/métodos , Humanos , Camundongos
16.
Comp Med ; 61(5): 404-11, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22330347

RESUMO

The arterivirus lactate dehydrogenase-elevating virus (LDV) causes life-long viremia in mice. Although LDV infection generally does not cause disease, infected mice that are homozygous for the Fv1(n) allele are prone to develop poliomyelitis when immunosuppressed, a condition known as age-dependent poliomyelitis. The development of age-dependent poliomyelitis requires coinfection with endogenous murine leukemia virus. Even though LDV is a common contaminant of transplantable tumors, clinical signs of poliomyelitis after inadvertent exposure to LDV have not been described in recent literature. In addition, LDV-induced poliomyelitis has not been reported in SCID or ICR mice. Here we describe the occurrence of poliomyelitis in ICR-SCID mice resulting from injection of LDV-contaminated basement membrane matrix. After exposure to LDV, a subset of mice presented with clinical signs including paresis, which was associated with atrophy of the hindlimb musculature, and tachypnea; in addition, some mice died suddenly with or without premonitory signs. Mice presenting within the first 6 mo after infection had regions of spongiosis, neuronal necrosis and astrocytosis of the ventral spinal cord, and less commonly, brainstem. Axonal degeneration of ventral roots prevailed in more chronically infected mice. LDV was identified by RT-PCR in 12 of 15 mice with typical neuropathology; positive antiLDV immunolabeling was identified in all PCR-positive animals (n = 7) tested. Three of 8 mice with neuropathology but no clinical signs were LDV negative by RT-PCR. RT-PCR yielded murine leukemia virus in spinal cords of all mice tested, regardless of clinical presentation or neuropathology.


Assuntos
Vírus Elevador do Lactato Desidrogenase , Vírus da Leucemia Murina , Poliomielite/veterinária , Doenças dos Roedores/patologia , Doenças dos Roedores/virologia , Animais , Membrana Basal/virologia , Primers do DNA/genética , Evolução Fatal , Feminino , Células HeLa , Humanos , Imuno-Histoquímica/veterinária , Camundongos , Camundongos SCID , Poliomielite/patologia , Poliomielite/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Medula Espinal/patologia , Medula Espinal/virologia
17.
J Virol ; 83(21): 11211-22, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19692462

RESUMO

Retroviruses can establish persistent infection despite induction of a multipartite antiviral immune response. Whether collective failure of all parts of the immune response or selective deficiency in one crucial part underlies the inability of the host to clear retroviral infections is currently uncertain. We examine here the contribution of virus-specific CD4(+) T cells in resistance against Friend virus (FV) infection in the murine host. We show that the magnitude and duration of the FV-specific CD4(+) T-cell response is directly proportional to resistance against acute FV infection and subsequent disease. Notably, significant protection against FV-induced disease is afforded by FV-specific CD4(+) T cells in the absence of a virus-specific CD8(+) T-cell or B-cell response. Enhanced spread of FV infection in hosts with increased genetic susceptibility or coinfection with Lactate dehydrogenase-elevating virus (LDV) causes a proportional increase in the number of FV-specific CD4(+) T cells required to control FV-induced disease. Furthermore, ultimate failure of FV/LDV coinfected hosts to control FV-induced disease is accompanied by accelerated contraction of the FV-specific CD4(+) T-cell response. Conversely, an increased frequency or continuous supply of FV-specific CD4(+) T cells is both necessary and sufficient to effectively contain acute infection and prevent disease, even in the presence of coinfection. Thus, these results suggest that FV-specific CD4(+) T cells provide significant direct protection against acute FV infection, the extent of which critically depends on the ratio of FV-infected cells to FV-specific CD4(+) T cells.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Vírus da Leucemia Murina de Friend/imunologia , Leucemia Experimental/imunologia , Ativação Linfocitária/imunologia , Infecções por Retroviridae/imunologia , Infecções Tumorais por Vírus/imunologia , Animais , Vírus Elevador do Lactato Desidrogenase/imunologia , Camundongos , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Interferon/genética , Receptores de Interferon/imunologia
18.
PLoS One ; 4(7): e6105, 2009 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-19568424

RESUMO

BACKGROUND: Lactate dehydrogenase-elevating virus (LDV) is a natural infectious agent of mice. Like several other viruses, LDV causes widespread and very rapid but transient activation of both B cells and T cells in lymphoid tissues and the blood. The mechanism of this activation has not been fully described and is the focus of the current studies. PRINCIPAL FINDINGS: A known inducer of early lymphocyte activation is IFNalpha, a cytokine strongly induced by LDV infection. Neutralization of IFNalpha in the plasma from infected mice ablated its ability to activate lymphocytes in vitro. Since the primary source of virus-induced IFNalpha in vivo is often plasmacytoid dendritic cells (pDC's), we depleted these cells prior to LDV infection and tested for lymphocyte activation. Depletion of pDC's in vivo eradicated both the LDV-induced IFNalpha response and lymphocyte activation. A primary receptor in pDC's for single stranded RNA viruses such as LDV is the toll-like receptor 7 (TLR7) pattern recognition receptor. Infection of TLR7-knockout mice revealed that both the IFNalpha response and lymphocyte activation were dependent on TLR7 signaling in vivo. Interestingly, virus levels in both TLR7 knockout mice and pDC-depleted mice were indistinguishable from controls indicating that LDV is largely resistant to the systemic IFNalpha response. CONCLUSION: Results indicate that LDV-induced activation of lymphocytes is due to recognition of LDV nucleic acid by TLR7 pattern recognition receptors in pDC's that respond with a lymphocyte-inducing IFNalpha response.


Assuntos
Células Dendríticas/metabolismo , Interferon-alfa/metabolismo , Vírus Elevador do Lactato Desidrogenase/fisiologia , Ativação Linfocitária/fisiologia , Receptor 7 Toll-Like/metabolismo , Animais , Camundongos , Camundongos Knockout
19.
Arch Virol ; 154(7): 1071-80, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19517211

RESUMO

Arteriviruses replicate in the cytoplasm and do not require the nucleus function for virus multiplication in vitro. However, nucleocapsid (N) protein of two arteriviruses, porcine reproductive respiratory syndrome virus and equine arteritis virus, has been observed to localize in the nucleus and nucleolus of virus-infected and N-gene-transfected cells in addition to their normal cytoplasmic distribution. In the present study, the N protein of lactate dehydrogenase-elevating virus (LDV) of mice was examined for nuclear localization. The subcellular localization of LDV-N was determined by tagging N with enhanced green fluorescence protein (EGFP) at the N- and C-terminus. Both N-EGFP and EGFP-N fusion proteins localized to the nucleus and nucleolus of gene-transfected cells. Labeled N also accumulated in the perinuclear region, the site of virus replication. The LDV-N sequence contains a putative 'pat4'-type nuclear localization signal (NLS) consisting of 38-KKKK. To determine its functional significance, a series of deletion constructs of N were generated and individually expressed in cells. The results showed that the 'pat4' NLS was essential for nuclear translocation. In addition, the LDV-N interacted with the importin-alpha and -beta proteins, suggesting that the LDV-N nuclear localization may occur via the importin-mediated nuclear transport pathway. These results provide further evidence for the nuclear localization of N as a common feature within the arteriviruses.


Assuntos
Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Vírus Elevador do Lactato Desidrogenase/metabolismo , Proteínas do Nucleocapsídeo/metabolismo , Células 3T3 , Sequência de Aminoácidos , Animais , Proteínas do Capsídeo/química , Nucléolo Celular/metabolismo , Núcleo Celular/metabolismo , Clonagem Molecular , Primers do DNA , Equartevirus/genética , Equartevirus/metabolismo , Genes Reporter , Células HeLa , Humanos , Vírus Elevador do Lactato Desidrogenase/genética , Camundongos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas do Nucleocapsídeo/química , Proteínas do Nucleocapsídeo/genética , Plasmídeos , Vírus da Síndrome Respiratória e Reprodutiva Suína/química , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Vírus da Síndrome Respiratória e Reprodutiva Suína/metabolismo , Deleção de Sequência , Transfecção
20.
Electromagn Biol Med ; 28(1): 1-14, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19337890

RESUMO

Cell-mediated immunity (CMI) response to different antigens was examined in healthy women, in patients with cervical precancerous lesions, and in patients with cervical cancer. Cervical lesions were diagnosed by cytological (PAP) smears, from examination by colposcopy, and from "punch" biopsy material by histology. CMI response is related to specific processes in healthy and cancer cells. CMI was investigated by leukocyte adherence inhibition (LAI) assay using specific antigen (prepared from cervical carcinoma tissue) and non specific antigen (prepared from blood of mice infected by LDH--lactate dehydrogenase--virus). The CMI responses of healthy women and cancer patients to the antigens used are different: the majority of T lymphocytes display adherence and non adherence, respectively (but the CMI responses elicited by the antigens are not equal and small quantitative differences are observed). Regardless of the CIN (cervical intraepithelial neoplasia) grades, CMI responses correspond either to healthy women or to cervical carcinoma patients (at about similar ratio of cases in all the CIN groups). Effect of non specific antigen suggests that cervical carcinoma transformation may be connected with reduction of mitochondrial activity similar to processes in LDH virus infection.


Assuntos
Imunidade Celular , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/imunologia , Antígenos de Neoplasias/metabolismo , Adesão Celular , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , L-Lactato Desidrogenase/metabolismo , Vírus Elevador do Lactato Desidrogenase/metabolismo , Leucócitos/citologia , Mitocôndrias/metabolismo , Lesões Pré-Cancerosas , Linfócitos T/patologia , Linfócitos T/virologia , Neoplasias do Colo do Útero/patologia
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