RESUMO
The treatment of open fractures is a challenge for the attending surgeon. Depending on the severity, the risk of infection rises up to 50%. Local infection up to the point of sepsis can develop in spite of surgical and antimicrobial therapy. The present case demonstrates the case of an 18-year-old man who developed toxic shock syndrome (TSS) after an open ankle fracture. This potentially life-threating syndrome usually presents with the main symptoms of fever, hypotension and exanthema and is caused by toxins, such as toxic shock syndrome toxin 1 (TSST-1) and staphylococcal enterotoxins A-D. In some cases it is associated with cardiopulmonary decompensation and can rapidly progress to multiorgan failure.
Assuntos
Fraturas do Tornozelo/diagnóstico , Fraturas do Tornozelo/terapia , Fraturas Expostas/diagnóstico , Fraturas Expostas/terapia , Choque Séptico/diagnóstico , Choque Séptico/terapia , Adolescente , Terapia Combinada/métodos , Diagnóstico Diferencial , Humanos , Masculino , Resultado do TratamentoRESUMO
Surveillance reports on infectious agents and their antibiotic resistance patterns as well as on the usage of antibiotics are now enforced by law for many medical institutions in Germany. However, specific practice-oriented recommendations concerning the appropriate extent and informative mode of presentation are lacking. This consensus statement resulted from the experience from five German university hospitals in handling data from infection epidemiology and in the various possibilities for the presentation of surveillance reports. The consensus statement provides recommendations for the preparation of the legally demanded surveillance reports, extending the existing regulations. The relevance of statements on frequency and quality of microbiological tests is included. Furthermore, modes for the standardization of the data analysis are suggested in order to achieve a regional and national comparability of the results on a high quality level, similarly to the established standardized surveillance of nosocomial infections. This consensus statement describes the form in which the legally enforced reports can be presented in an informative and standardized way in order to facilitate the deduction and realization of preventive measurements.
Assuntos
Infecções Bacterianas/diagnóstico , Infecções Bacterianas/prevenção & controle , Técnicas Bacteriológicas/normas , Notificação de Doenças/normas , Farmacorresistência Bacteriana , Vigilância da População/métodos , Guias de Prática Clínica como Assunto , Infecções Bacterianas/epidemiologia , Alemanha/epidemiologia , HumanosRESUMO
The program package "Integrated Bulletin for Infectious disease Surveillance for Schleswig-Holstein" (IBIS(SH)) was introduced in 2008 for the automated data analysis of notifiable infectious diseases in Schleswig-Holstein, Germany. The Java-based IBIS(SH) software supports access to the national SurvNet@RKI reporting data via Access and MS SQL. The aim of the IBIS(SH) system is early warning and interpretation of clusters and monitoring of trends. One module of the system permits the analysis of temporal aberration by comparison of data from previous years. The interpretation system is based on the weekly median and on percentile values from previous years. The extent of an aberration is assessed by a five-step score magnitude scale. Another module permits the detection of regional clusters by the weekly assessment of a population-based risk analysis. IBIS(SH) automatically generates tables and graphs for the weekly bulletin and their allocation in the Internet. Data for the most relevant pathogens in Schleswig-Holstein are presented for the year 2009. The performance of the automated temporal and the regional detection systems are compared to outbreak detection by local health authorities.
Assuntos
Controle de Doenças Transmissíveis/métodos , Doenças Transmissíveis/epidemiologia , Notificação de Doenças/métodos , Notificação de Doenças/estatística & dados numéricos , Computação Matemática , Vigilância da População/métodos , Software , Análise por Conglomerados , Gráficos por Computador , Alemanha , HumanosRESUMO
To obtain reliable, regionalized, and timely data for the spread of seasonal influenza in various age groups, which are preferentially affected by the influenza virus, a syndromic surveillance system for acute respiratory tract infections in Schleswig-Holstein (SHARE) was established in preschools and nurseries starting in 2006. The Schleswig-Flensburg district with 12 of 114 preschools and nurseries and 850 of 5,750 supervised children served as a pilot district. The weekly rates of sickness absenteeism correlated most strongly with the onset of seasonal influenza and with population density during the first half of the year. Mean annual sickness absenteeism levels of above 6% occurred more frequently above a population density of 200 inhabitants/km(2) than below this density (relative risk 2.50, 95% confidence interval 1.18-5.32). By analysis of the receiver-operating characteristic curve, the diagnostic performance of the SHARE system as a classifier for seasonal influenza was determined. The sensitivity was 83% and the specificity was 79% when sickness absence rates exceeded 5%. The performance of the SHARE system correlated with the size of the kindergarten. In 2008, 13 of 15 districts of Schleswig-Holstein participated with 157 of 1,684 kindergarten and 10,300 of 113,000 children. The evaluation for 2008 confirmed that the SHARE system is suitable for the surveillance of seasonal influenza at the district and state levels.
Assuntos
Creches/estatística & dados numéricos , Influenza Humana/epidemiologia , Vigilância da População/métodos , Infecções Respiratórias/epidemiologia , Escolas Maternais/estatística & dados numéricos , Absenteísmo , Doença Aguda , Pré-Escolar , Coleta de Dados , Feminino , Alemanha , Humanos , Influenza Humana/classificação , Masculino , Projetos Piloto , Densidade Demográfica , Curva ROC , Infecções Respiratórias/classificação , SíndromeRESUMO
BACKGROUND: This article describes multiple transmissions of rabies via transplanted solid organ from a single infected donor. The empirical Milwaukee treatment regimen was used in the recipients. METHODS: Symptomatic patients were treated by deep sedation (ketamine, midazolam, and phenobarbital), ribavirin, interferon, and active and passive vaccination. Viral loads and antibodies were continuously monitored. RESULTS: Recipients of both cornea and liver transplants developed no symptoms. The recipient of the liver transplant had been vaccinated approximately 20 years before transplantation. Two recipients of kidney and lung transplants developed rabies and died within days of symptomatic disease. Another kidney recipient was treated 7 weeks before he died. The cerebrospinal fluid viral load remained at constant low levels (<10,000 copies/mL) for approximately 5 weeks; it increased suddenly by almost 5 orders of magnitude thereafter. After death, no virus was found in peripheral compartments (nerve tissue, heart, liver, or the small intestine) in this patient, in contrast to in patients in the same cohort who died early. CONCLUSIONS: Our report includes, to our knowledge, the longest documented treatment course of symptomatic rabies and the first time that the virus concentration was measured over time and in different body compartments. The postmortem virus concentration in the periphery was low, but there was no evidence of a reduction of virus in the brain.
Assuntos
Anticorpos Antivirais/administração & dosagem , Antivirais/uso terapêutico , Hipnóticos e Sedativos/uso terapêutico , Transplante de Órgãos/efeitos adversos , Vacina Antirrábica/administração & dosagem , Vírus da Raiva/isolamento & purificação , Raiva/tratamento farmacológico , Adulto , Idoso , Anticorpos Antivirais/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vacina Antirrábica/imunologia , Resultado do Tratamento , Carga ViralRESUMO
The rhadinovirus herpesvirus saimiri (HVS) as a gene delivery vector allows large DNA insertions and long-termed gene expression. In the case of T-cell transduction, such vectors use the viral transformation-associated genes of HVS C488 for T-cell amplification. In this report, we investigated whether the gene for the catalytic telomerase subunit human telomerase reverse transcriptase (hTERT) can substitute for the transformation-associated genes in rhadinoviral T-cell transduction and amplification. By using virus mutants generated by en passant mutagenesis from bacterial artificial chromosomes, we observed a very early and functional transgene expression even by virus mutants without transformation-associated genes. The markers of T-cell transformation by HVS, namely CD2 hyperreactivity, overexpression of interleukin-26, and of the tyrosine kinase Lyn could neither be induced nor enhanced by ectopic hTERT expression. When the viral transformation-associated genes were replaced by the hTERT gene, it was not sufficient for growth transformation, although hTERT was efficiently transduced and functionally expressed by the rhadinovirus vector. Thus, the transformation-associated proteins StpC and Tip are responsible for the T-cell phenotype after transduction by HVS and, additionally, modulate telomerase activity independently of hTERT expression.
Assuntos
Transformação Celular Viral/genética , Vetores Genéticos , Herpesvirus Saimiriíneo 2/genética , Linfócitos T/enzimologia , Telomerase/genética , Transdução Genética/métodos , Antígenos CD2/imunologia , Herpesvirus Saimiriíneo 2/imunologia , Humanos , Interleucinas/imunologia , Fosfoproteínas/genética , Proteínas Virais/genética , Quinases da Família src/análise , Quinases da Família src/imunologiaRESUMO
Varicella zoster virus is the most frequent cause of acute retinal necrosis (ARN) followed by herpes simplex virus. Retinal ischemia and optic nerve atrophy are the main causes of the frequently poor final visual outcome in severe cases of ARN. The clinical diagnosis of ARN should be made as early as possible. Acyclovir should be administered intravenously due to its unreliable oral bioavailability. Systemic corticosteroids should be applied to suppress tissue damage caused by the host's inflammatory response. Severe cases of ARN should be treated by early vitrectomy with diagnostic vitreous biopsy, intravitreal aciclovir lavage, intraoperative laser retinopexy and silicone oil tamponade. The role of prophylactic laser retinopexy for prevention of secondary retinal detachment remains to be determined. The cause of different degrees of severity of ARN is unknown. The degree of severity of ARN is probably an independent predictor of the functional outcome.
Assuntos
Infecções Oculares Virais/diagnóstico , Infecções Oculares Virais/terapia , Síndrome de Necrose Retiniana Aguda/diagnóstico , Síndrome de Necrose Retiniana Aguda/terapia , Infecções Oculares Virais/complicações , Humanos , Síndrome de Necrose Retiniana Aguda/etiologiaRESUMO
Acute retinal necrosis occurs in approximately one per million persons per year and is caused in approximately 70% of the cases by the varicella zoster virus or in about 30% of the cases by herpes simplex virus. The early diagnosis is primarily based on virus-specific polymerase chain reaction in fluid from the anterior chamber or vitreous humor and can be supported by the determination of specific antibody titers from fluid and serum. Virus detection provides the basis for early causative therapy which limits disease progression and risk of complications. Retinal infections by varicella zoster virus or herpes simplex virus are treated with aciclovir, ganciclovir, or famciclovir. Ganciclovir and valganciclovir are used for the therapy of retinal cytomegalovirus infections. In the case of resistance development, foscarnet or cidofovir are available as second line antiviral drugs. The early use of specific antiviral agents is a crucial prerequisite for optimized therapy of acute retinal necrosis.
Assuntos
Infecções Oculares Virais/diagnóstico , Infecções Oculares Virais/terapia , Síndrome de Necrose Retiniana Aguda/diagnóstico , Síndrome de Necrose Retiniana Aguda/terapia , Infecções Oculares Virais/virologia , Humanos , Síndrome de Necrose Retiniana Aguda/virologiaRESUMO
BACKGROUND: Necrotising retinopathy in immunocompromised hosts is characterised by an unfavourable course often with unspecific clinical features. Therefore, differential diagnosis can be critical. HISTORY AND SIGNS: A case of an initially therapy-resistant, necrotizing retinopathy is presented in a 65-year-old immunocompromised male patient suffering from chronic B-cell leukemia. THERAPY AND OUTCOME: Despite demonstration of cytomegalovirus and Varicella-Zoster-Virus DNA by polymerase chain reaction in vitreous, aqueous humour samples and from retinal biopsy with specific antiviral therapy, a progression of retinal necrosis was noted. Finally Toxoplasma gondii DNA was detected and retinal necrosis resolved after specific treatment. However, visual acuity remains poor because of optic nerve atrophy. CONCLUSIONS: The polymerase chain reaction is an important diagnostic tool for differential diagnosis in immunocompromised patients suffering from necrotising retinopathy. If resistance to therapy is noted atypical ocular toxoplasmosis should be considered. The presented case report shows that even multiple infections are possible in the same host.
Assuntos
Coriorretinite/diagnóstico , Infecções por Citomegalovirus/diagnóstico , Citomegalovirus/fisiologia , Herpes Zoster Oftálmico/diagnóstico , Herpesvirus Humano 3 , Leucemia Linfocítica Crônica de Células B/imunologia , Infecções Oportunistas/diagnóstico , Toxoplasmose Ocular/diagnóstico , Ativação Viral , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cegueira/diagnóstico , Cegueira/imunologia , Clorambucila/administração & dosagem , Clorambucila/efeitos adversos , Coriorretinite/imunologia , Comorbidade , Infecções por Citomegalovirus/imunologia , Seguimentos , Herpes Zoster Oftálmico/imunologia , Herpesvirus Humano 3/fisiologia , Humanos , Tolerância Imunológica/imunologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Masculino , Infecções Oportunistas/imunologia , Atrofia Óptica/diagnóstico , Atrofia Óptica/imunologia , Prednisolona/administração & dosagem , Prednisolona/efeitos adversos , Síndrome de Necrose Retiniana Aguda/diagnóstico , Síndrome de Necrose Retiniana Aguda/imunologia , Toxoplasmose Ocular/imunologia , Ativação Viral/imunologiaRESUMO
Herpesvirus saimiri is capable of transforming T lymphocytes of various primate species to stable growth in culture. The interaction of the T-cellular tyrosine kinase p56(lck) with the transformation-associated viral protein Tip has been shown before to activate the kinase and provides one model for the T-cell-specific transformation by herpesvirus saimiri subgroup C strains. In contrast to other primate species, squirrel monkeys (Saimiri sciureus) are naturally infected with the virus without signs of lymphoma or other disease. Although the endogenous virus was regularly recovered from peripheral blood cells from squirrel monkeys, we observed that the T cells lost the virus genomes in culture. Superinfection with virus strain C488 did not induce growth transformation, in contrast to parallel experiments with T cells of other primate species. Surprisingly, p56(lck) was enzymatically inactive in primary T-cell lines derived from different squirrel monkeys, although the T cells reacted appropriately to stimulatory signals. The cDNA sequence revealed minor point mutations only, and transfections in COS-7 cells demonstrated that the S. sciureus lck gene codes for a functional enzyme. In S. sciureus, the tyrosine kinase p56(lck) was not activated after T-cell stimulation and enzymatic activity could not be induced by Tip of herpesvirus saimiri C488. However, the suppression of p56(lck) was partially released after administration of the phosphatase inhibitor pervanadate. This argues for unique species-specific conditions in T cells of S. sciureus which may interfere with the transforming activity and pathogenicity of herpesvirus saimiri subgroup C strains in their natural host.
Assuntos
Infecções por Herpesviridae/imunologia , Herpesvirus Saimiriíneo 2/fisiologia , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/imunologia , Linfócitos T/imunologia , Linfócitos T/virologia , Infecções Tumorais por Vírus/imunologia , Sequência de Aminoácidos , Animais , Transformação Celular Viral , Regulação para Baixo , Infecções por Herpesviridae/enzimologia , Humanos , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/metabolismo , Dados de Sequência Molecular , Saimiri , Alinhamento de Sequência , Linfócitos T/enzimologia , Replicação ViralRESUMO
Varicella-zoster virus (VZV) is a widespread human herpes virus causing chicken pox on primary infection and persisting in sensory neurons. Reactivation causes shingles, which are characterized by severe pain and often lead to postherpetic neuralgia. To elucidate the mechanisms of VZV-associated hyperalgesia, we elaborated an in vitro model for the VZV infection of sensory neurons from rat dorsal root ganglia. Between 35 and 50% of the neurons showed strong expression of the immediate-early virus antigens IE62 and IE63 and the late glycoprotein gE. When the intracellular calcium concentration was monitored microfluorometrically for individual cells after infection, the sensitivity to GABA or capsaicin was similar in controls and in VZV-infected neurons. However, the baseline calcium concentration was increased. Neurons became de novo sensitive to adrenergic stimulation after VZV infection. Norepinephrine-responsive neurons were more frequent and calcium responses to norepinephrine were significantly higher after infection with wild-type isolates than with the attenuated vaccine strain OKA. The adrenergic agonists phenylephrine and isoproterenol had similar efficacy. We suggest that the infection with wild-type VZV isolates confers norepinephrine sensitivity to sensory neurons by using alpha(1)- and/or beta(1)-adrenergic receptors providing a model for the pathophysiology of the severe pain associated with the acute reactivation of VZV.
Assuntos
Gânglios Espinais/efeitos dos fármacos , Herpes Zoster/patologia , Herpesvirus Humano 3 , Neurônios Aferentes/efeitos dos fármacos , Norepinefrina/farmacologia , Animais , Células Cultivadas , Técnicas de Cocultura , Feminino , Gânglios Espinais/patologia , Gânglios Espinais/virologia , Humanos , Neurônios Aferentes/metabolismo , Neurônios Aferentes/virologia , Ratos , Ratos Wistar , Receptores Adrenérgicos/metabolismoRESUMO
Herpesvirus saimiri (saimiriine herpesvirus 2) is the classical prototype of the gamma(2)-herpesviruses or rhadinoviruses, which also contains a human member, the Kaposi's sarcoma-associated herpesvirus. The T-lymphotropic Herpesvirus saimiri establishes specific replicative and persistent conditions in different primate host species. Virtually all squirrel monkeys (Saimiri sciureus) are persistently infected with this virus. In its natural host, the virus does not cause disease, whereas it induces fatal acute T-cell lymphoma in other monkey species after experimental infection. The virus can be isolated by cocultivation of permissive epithelial cells with peripheral blood cells from naturally infected squirrel monkeys and from susceptible New World monkeys during the virus-induced disease. Tumour-derived and in vitro-transformed T-cell lines from New World monkeys release virus particles. Herpesvirus ateles is a closely related virus of spider monkeys (Ateles spp.) and has similar pathogenic properties to Herpesvirus saimiri in other New World primate species. Similar to other rhadinoviruses, the genome of Herpesvirus saimiri harbours a series of virus genes with pronounced homology to cellular counterparts including a D-type cyclin, a G-protein-coupled receptor, an interleukin-17, a superantigen homologue, and several inhibitors of the complement cascade and of different apoptosis pathways. Preserved function has been demonstrated for most of the homologues of cellular proteins. These viral functions are mostly dispensable for the transforming and pathogenic capability of the virus. However, they are considered relevant for the apathogenic persistence of Herpesvirus saimiri in its natural host. A terminal region of the non-repetitive coding part of the virus genome is essential for pathogenicity and T-cell transformation. Based on the pathogenic phenotypes and the different alleles of this variable region, the virus strains have been assigned to three subgroups, termed A, B and C. In the highly oncogenic subgroup C strains, the two virus genes stpC and tip are transcribed from one bicistronic mRNA and are essential for transformation and leukaemia induction. stpC fulfils the typical criteria of an oncogene; its product interacts with Ras and tumour necrosis factor-associated factors and induces mitogen-activated protein kinase and nuclear factor kappa B activation. Tip interacts with the RNA transport factor Tap, with signal transduction and activation of transcription factors, and with the T-cellular tyrosine kinase Lck, which is activated by this interaction and phosphorylates Tip as a substrate. It is of particular interest that certain subgroup C virus strains such as C488 are capable of transforming human T lymphocytes to stable growth in culture. The transformed human T cells harbour multiple copies of the viral genome in the form of stable, non-integrated episomes. The cells express only a few virus genes and do not produce virus particles. The transformed cells maintain the antigen specificity and many other essential functions of their parental T-cell clones. Based on the preserved functional phenotype of the transformed T cells, Herpesvirus saimiri provides useful tools for T-cell immunology, for gene transfer and possibly also for experimental adoptive immunotherapy.
Assuntos
Infecções por Herpesviridae/virologia , Herpesvirus Saimiriíneo 2/genética , Infecções Tumorais por Vírus/virologia , Animais , Transformação Celular Viral , Técnicas de Transferência de Genes , Genes Virais , Vetores Genéticos , Genoma Viral , Infecções por Herpesviridae/patologia , Herpesvirus Saimiriíneo 2/fisiologia , Humanos , Linfócitos T/virologia , Infecções Tumorais por Vírus/patologia , Replicação ViralRESUMO
Herpesviruses occur in two distinct forms of infection, lytic replication and latent persistence. In this study, we investigated the molecular mechanisms that govern the latent-lytic switch in the prototype gamma-2 herpesvirus, herpesvirus saimiri (HVS). We utilized a persistently HVS-infected A549 cell line, in which HVS DNA is stably maintained as nonintegrated circular episomes, to assess the role of the open reading frame 50 (ORF 50) (Rta) proteins in the latent-lytic switch. Northern blot analysis and virus recovery assays determined that the ORF 50a gene product, when expressed under the control of a constitutively active promoter, was sufficient to reactivate the entire lytic replication cycle, producing infectious virus particles. Furthermore, although the ORF 50 proteins of HVS strains A11 and C488 are structurally divergent, they were both capable of inducing the lytic replication cycle in this model of HVS latency.
Assuntos
Herpesvirus Saimiriíneo 2/fisiologia , Fases de Leitura Aberta/genética , Transativadores/metabolismo , Proteínas Virais/metabolismo , Ativação Viral , Replicação Viral , DNA Viral/biossíntese , DNA Viral/genética , Regulação Viral da Expressão Gênica , Herpesvirus Saimiriíneo 2/genética , Humanos , Transativadores/genética , Células Tumorais Cultivadas , Proteínas Virais/genética , Latência ViralRESUMO
Herpesvirus saimiri can be used as an efficient gene expression vector for human T lymphocytes and thus may allow applications in experimental leukemia therapy. We constructed recombinant viruses for the functional expression of the thymidine kinase (TK) of herpes simplex virus type 1 (HSV) as a suicide gene. These viruses reliably allowed the targeted elimination of transduced nonpermissive human T cells in vitro after the administration of ganciclovir. To test the reliability of this function under the most stringent permissive conditions, in this study we analyzed the influence of the prodrugs ganciclovir and acyclovir in common marmosets on the acute leukemogenesis induced by either wild-type herpesvirus saimiri C488 or by a recombinant derivative expressing TK of HSV. Antiviral drug treatment did not influence the rapid development of acute disease. In contrast, the presence of the HSV tk gene resulted in a faster disease progression. In addition, HSV TK-expressing viruses showed faster replication than wild-type virus in culture at low serum concentrations. Thus, HSV TK accelerates the replication of herpesvirus saimiri and enhances its pathogenicity. This should be generally considered when HSV TK is applied as a transgene in replication-competent DNA virus vectors for gene therapy.
Assuntos
Herpes Simples/patologia , Leucemia de Células T/fisiopatologia , Simplexvirus/genética , Simplexvirus/patogenicidade , Linfócitos T/virologia , Timidina Quinase/metabolismo , Aciclovir/farmacologia , Animais , Callithrix , Linhagem Celular , Células Cultivadas , Ganciclovir/farmacologia , Vetores Genéticos , Humanos , Leucemia de Células T/patologia , Simplexvirus/enzimologia , Linfócitos T/efeitos dos fármacos , Timidina Quinase/genética , VirulênciaRESUMO
Herpesvirus saimiri transforms human T lymphocytes to stable growth and persists episomally without genomic integration and without virus production. The transformed T cells retain essential features of their parental cells including the MHC-restricted antigen specificity which may be useful for applications in adoptive immunotherapy. In order to improve the biological safety of such vectors, the prodrug activating gene thymidine kinase of herpes simplex virus was inserted into the genome of herpesvirus saimiri by homologous recombination. After infection with wild-type or cloned recombinant viruses, T cells from tamarin monkeys and from humans were transformed to stable growth. Thymidine kinase-expressing transformed T cells were efficiently eliminated in the presence of low concentrations of ganciclovir. This elimination mechanism remained fully functional over an observation period of 12 months. The potentially immunogenic neomycin resistance gene expression cassette was deleted from the genome of established mutant viruses by using the prokaryotic Cre/LoxP recombination system. At any time during the course of a therapeutic application, thymidine kinase-expressing transformed human T cells might be eliminated after administration of ganciclovir. In principle, this function could be useful for the T cell-dependent immunotherapy of resistant blood cancer while avoiding the risk of uncontrolled graft-versus-host disease.
Assuntos
Terapia Genética/métodos , Vetores Genéticos/administração & dosagem , Herpesvirus Saimiriíneo 2/genética , Linfócitos T/enzimologia , Timidina Quinase/genética , Aciclovir/uso terapêutico , Animais , Antimetabólitos Antineoplásicos/uso terapêutico , Antivirais/uso terapêutico , Células Cultivadas , Fluoruracila/uso terapêutico , Ganciclovir/uso terapêutico , Expressão Gênica , Vetores Genéticos/genética , Humanos , Recombinação Genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saguinus , TransgenesRESUMO
Human T cells are transformed in vitro to stable growth after infection with herpesvirus saimiri subgroup C strain C488, and they retain their antigen-specific reactivity and other important functional features of mature activated T lymphocytes. The virus persists as nonintegrating episomes in human T cells under restricted viral gene expression and without production of virus particles. This study analyzes the behavior of herpesvirus-transformed autologous T cells after reinfusion into the donor under close-to-human experimental conditions. T cells of 5 macaque monkeys were transformed to stable interleukin-2 dependent growth and were intravenously infused into the respective donor. The animals remained healthy, without occurrence of lymphoma or leukemia for an observation period of more than 1 year. Over several months virus genomes were detectable in peripheral blood cells and in cultured T cells by polymerase chain reaction. In naive control animals, a high-dose intravenous infection rapidly induced pleomorphic peripheral T-cell lymphoma. In contrast, monkeys were protected from lymphoma after challenge infection if they had previously received autologous T-cell transfusions. High levels of antibodies against virus antigens were detectable after challenge infection only. Taken together, herpesvirus-transformed T cells are well tolerated after autologous reinfusion. This may allow us to develop a novel concept for adoptive T-cell mediated immunotherapy.
Assuntos
Transformação Celular Viral , Herpesvirus Saimiriíneo 2 , Tolerância Imunológica , Linfoma/etiologia , Linfoma/patologia , Linfócitos T/patologia , Transferência Adotiva , Animais , Transfusão de Sangue Autóloga , Humanos , Imunoterapia Adotiva , Transfusão de Linfócitos , Macaca mulatta , Linfócitos T/imunologia , Linfócitos T/virologiaRESUMO
Although herpesvirus saimiri-transformed T lymphocytes retain multiple normal T-cell functions, only a few changes have been described. By subtractive hybridization, we have isolated a novel cellular gene, ak155, a sequence homolog of the interleukin-10 gene. Specifically herpesvirus saimiri-transformed T cells overexpress ak155 and secrete the protein into the supernatant. In other T-cell lines and in native peripheral blood cells, but not in B cells, ak155 is transcribed at low levels. AK155 forms homodimers similarly to interleukin-10. As a lymphokine, AK155 may contribute to the transformed phenotype of human T cells after infection by herpesvirus saimiri.
Assuntos
Transformação Celular Viral , Herpesvirus Saimiriíneo 2/fisiologia , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucinas , Linfócitos T/virologia , Sequência de Aminoácidos , Linhagem Celular Transformada , Clonagem Molecular , Humanos , Interleucina-10/química , Ativação Linfocitária , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Linfócitos T/imunologia , Transcrição GênicaRESUMO
The transformation-associated region of herpesvirus saimiri strains is variable, whereas other parts of the virus genome are highly conserved. However, we observed considerable interstrain sequence divergence of the early viral regulatory orf50 gene, which encodes the R transactivator, a homolog of Epstein-Barr virus BRLF1. The orf50 gene of strain C488 was transcribed at low abundance during lytic infection, whereas antisense transcripts were simultaneously expressed at high levels. A spliced variant, orf50a, was detectable by RT-PCR and RNase protection assays in stimulated C488-transformed, nonpermissive human T cells. In contrast to strain A11, the short, unspliced orf50b form of C488 displayed complete transactivation capability on the orf6 and orf57 promoters. In summary, there are unexpected structural and functional differences between the orf50 genes of herpesvirus saimiri strains, which differ in their capability to transform human T lymphocytes.
Assuntos
Transformação Celular Viral , Herpesvirus Saimiriíneo 2/genética , Herpesvirus Saimiriíneo 2/fisiologia , Linfócitos T/virologia , Transativadores/genética , Ativação Transcricional , Sequência de Aminoácidos , Animais , Linhagem Celular Transformada , Regulação Viral da Expressão Gênica , Genes Virais , Humanos , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transativadores/química , Replicação ViralAssuntos
Produtos do Gene env/genética , Infecções por HIV/virologia , HIV-2/genética , Sequência de Aminoácidos , Linhagem Celular , DNA Viral/análise , HIV-2/isolamento & purificação , Humanos , Leucócitos Mononucleares/virologia , Dados de Sequência Molecular , Tropismo , Produtos do Gene env do Vírus da Imunodeficiência HumanaRESUMO
A better characterisation of mononuclear cell-tropic (M-tropic) HIV-1 is central to disease control as these viruses predominate in disease transmission. M-tropic viruses do not replicate in conventional T-cell lines, and virus titres obtained in peripheral blood mononuclear cells (PBMC) are low. Human T-lymphocytes which have been immortalised by Herpesvirus saimiri strain C488 (HVS T-cells) are highly permissive to the replication of T-cell tropic strains of HIV. This study aimed to determine if HVS T-cells support replication of M-tropic HIV isolates that have not been adapted to conventional T-cell lines. A panel of PBMC low passage/primary field isolates and their molecular clones was used. Results show that infection in HVS T-cells was longer lived than in PBMC. In terms of peak virus titre and duration of productive infection, the two HVS T-cell lines studied were superior to PBMC, and one supported enhanced replication of all M-tropic isolates. This is important for generating M-tropic virus pools of sufficient titre for further biological studies such as virus neutralisation, co receptor usage and testing of antivirals. Phenotypic analysis showed that HVS T-cells are CD4+-activated memory cells expressing both CXCR-4 and CCR5 co receptors. Thus, HVS immortalisation appears to select for the T-cell subset targeted by HIV-1 in vivo.