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1.
Vet Parasitol ; 284: 109194, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32866837

RESUMO

Canine heartworm disease (CHD) results from infection with Dirofilaria immitis and while it is of global concern, it is most prevalent in tropical climates where conditions support the parasite and vector life cycles. Melarsomine dihydrochloride is the sole treatment for CHD recommended by the American Heartworm Society. However, in cases where cost or access to melarsomine precludes treatment of an infected dog, therapeutic alternatives are warranted. This randomized, controlled field study evaluated the adulticidal efficacy of a combination therapeutic protocol using 10 % imidacloprid + 2.5 % moxidectin spot-on and a single 28-day course of doxycycline and compared with that of a 2-dose melarsomine dihydrochloride protocol. Of 37 naturally-infected domestic dogs with class 1, 2 or early class 3 CHD enrolled in the study, 30 were evaluated for a minimum of 12 months. Seven dogs were withdrawn due to canine ehrlichiosis, non-compliance, or wrongful inclusion. Dogs were randomly assigned to a control (CP, n = 15) or investigational (IVP, n = 15) treatment group. CP dogs received two injections of melarsomine dihydrochloride (2.5 mg/kg) 24 -hs apart and maintained on monthly ivermectin/pyrantel. IVP dogs were treated with oral doxycycline (10 mg/kg twice daily for 28 days) and topical 10 % imidacloprid + 2.5 % moxidectin once monthly for 9 months. Dogs were evaluated up to 18 months - monthly for the first 9 months, then every 3 months. Parasiticidal efficacy was based on antigen status using the IDEXX PetChek® 34 Heartworm-PF Antigen test. By month 18, antigen was not detected in any study dog except one from the IVP group. One other IVP dog was persistently antigenemic and treated with melarsomine at month 12 according to the initial study protocol. Mean antigen concentration (based on optical density) decreased more rapidly in the CP group and by month 15 was 0.11 for the IVP and 0.07 for CP groups, with equivalent median concentrations (0.04) in both groups. Conversion following heat-treatment of antigen-negative samples occurred frequently and at similar rates in both treatment groups. Based on the bias of diagnostic tests towards detection of female worms, we conclude that monthly application of 10 % imidacloprid + 2.5 % moxidectin for 9 months combined with a course of doxycycline twice daily for 28 days resulted in effective therapy against female adults in CHD. This therapeutic option may be particularly useful in cases where financial constraint or access to melarsomine precludes treatment of an infected individual. This study was supported by Bayer Animal Health.


Assuntos
Dirofilariose/tratamento farmacológico , Dirofilariose/prevenção & controle , Doenças do Cão/tratamento farmacológico , Doenças do Cão/prevenção & controle , Quimioterapia Combinada/veterinária , Filaricidas/uso terapêutico , Animais , Dirofilaria immitis , Cães , Doxiciclina/administração & dosagem , Feminino , Granada , Macrolídeos/administração & dosagem , Neonicotinoides/administração & dosagem , Nitrocompostos/administração & dosagem
2.
Anaesth Intensive Care ; 46(2): 197-201, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29519223

RESUMO

The objective of this retrospective cohort study was to assess mortality and morbidity after cardiac arrest in hospital inpatients aged 80 years or older, in an Australian tertiary hospital. We studied patients aged 80 years or older who suffered an in-hospital cardiac arrest from 1 January 2000 to 31 December 2016. The main outcome measures were one-year survival and narrative morbidity. Two hundred and eighty-five patients were identified. Absolute one-year survival after cardiac arrest was, at best, 12.6%. Narrative descriptions of morbidity demonstrate high healthcare utilisation, dependency or residential care, and significant impairments of physical and social function. In conclusion, one-year survival after cardiac arrest in the very elderly is poor. In those who survive, significant morbidity is present.


Assuntos
Parada Cardíaca/mortalidade , Idoso de 80 Anos ou mais , Mortalidade Hospitalar , Humanos , Morbidade , Estudos Retrospectivos , Centros de Atenção Terciária
3.
Trop Biomed ; 31(2): 347-50, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25134904

RESUMO

American trypanosomiasis (Chagas disease) caused by the protozoan parasite Trypanosoma cruzi is endemic to parts of South America and the Caribbean. Infected dogs are important in the epidemiology of the parasite as they can play a role in the transmission of the parasite to humans. A total of 399 dog sera (242 stray and 157 pet dogs) were examined for T. cruzi infection; using a qualitative immunochromatographic dipstick test, based on recombinant antigens specific for American trypanosomiasis (Trypanosoma detect rapid test; InBios international, Inc., Seattle, Washington). Overall seroprevalence for T. cruzi was estimated at 10.5% (95% confidence interval: 7.5% to 13.5%); with stray dogs being significantly more affected (p<0.05, χ2). Results from this study indicate that dogs in Grenada are moderately exposed to T. cruzi compared to other areas in the region.


Assuntos
Anticorpos Antiprotozoários/sangue , Doença de Chagas/veterinária , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Trypanosoma cruzi/imunologia , Animais , Antígenos de Protozoários , Doença de Chagas/epidemiologia , Cromatografia de Afinidade , Cães , Granada/epidemiologia , Estudos Soroepidemiológicos
4.
Anim Genet ; 42(5): 560-2, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21906109

RESUMO

Datapoint errors in pedigree genotype data sets are difficult to identify and adversely affect downstream genetic analyses. We present GenotypeChecker, a desktop software tool for assisting data cleansing. The application identifies likely data errors in pedigree/genotype data sets by performing an inheritance-checking algorithm for each marker across the pedigree, and highlights inconsistently inherited genotypes in an exploratory user interface. By 'masking' suspect datapoints and rechecking inheritance consistency, erroneous datapoints can be confirmed and cleansed from the data set. The software, examples and documentation are freely available at http://bioinformatics.roslin.ac.uk/genotypechecker.


Assuntos
Genótipo , Linhagem , Software , Genética Médica , Humanos
5.
J Plast Reconstr Aesthet Surg ; 64(11): 1417-23, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21729825

RESUMO

BACKGROUND: The face can be reanimated after long-term paralysis by free microneurovascular tissue transfer. Flaps from gracilis and pectoralis minor usually require a two-stage procedure with a cross-face nerve graft. Latissimus dorsi has a much longer muscular nerve, the thoracodorsal nerve, which could avoid the need for a second cross-face nerve graft. Our hypothesis is that the neurovascular pedicles of small segments of latissimus dorsi would be long enough to reach the opposite side of the face and to provide a reliable blood and nerve supply to the flaps. METHOD: To test this hypothesis the thoracodorsal pedicle and its primary branches were dissected in eleven embalmed cadavers. The segmental vessels and nerves were then traced in a series of simulated flaps approximately 8-10 cm × 2-3 cm by micro-dissection, tissue clearing and histology. RESULTS: The thoracodorsal pedicle is 10-14 cm long to where it enters the muscle, and with intra-muscular dissection small chimeric muscle segments 8-10 cm × 2-3 cm can be raised with a clearly defined neurovascular supply. Using micro-dissection the neurovascular pedicle can be lengthened to reach across the face. Segmental arteries and nerves extended to the distal end of all the flaps examined. Artery, vein and nerve run together and are of substantial diameter. CONCLUSION: Small muscle segments of latissimus dorsi can be raised on long neurovascular pedicles. The vessels and nerves are substantial and the likelihood of surgical complications such as flap necrosis and functional disuse on transplantation appear low. Although in our opinion the use of cross-face nerve grafts and transfer of smaller muscle flaps remains the gold standard in facial reanimation in straightforward cases, the micro-dissected latissimus dorsi flap is a useful option in complex cases of facial reanimation. CLINICAL APPLICATION: Facial reanimation using micro-dissected segments of latissimus dorsi has been performed in four complex cases of facial paralysis.


Assuntos
Expressão Facial , Paralisia Facial/cirurgia , Retalhos de Tecido Biológico , Músculo Esquelético/transplante , Adulto , Cadáver , Paralisia Facial/etiologia , Feminino , Retalhos de Tecido Biológico/irrigação sanguínea , Retalhos de Tecido Biológico/inervação , Humanos , Neoplasias Maxilares/cirurgia , Pessoa de Meia-Idade , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/inervação , Neuroma Acústico/cirurgia , Neoplasias Parotídeas/cirurgia , Complicações Pós-Operatórias/cirurgia , Resultado do Tratamento
6.
OMICS ; 10(2): 220-30, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16901230

RESUMO

The names used by biologists to label the observations they make are imprecise. This is an issue as workers increasingly seek to exploit data gathered from multiple, unrelated sources on line. Even when the international codes of nomenclature are followed strictly the resulting names (Taxon Names) do not uniquely identify the taxa (Taxon Concepts) that have been described by taxonomists but merely groups of type specimens. A standard data model for exchange of taxonomic information is described. It addresses this issue by facilitating explicit communication of information about Taxon Concepts and their associated names. A representation of this model as a XML Schema is introduced and the implications of the use of Globally Unique Identifiers discussed.


Assuntos
Classificação , Biologia Computacional/normas , Padrões de Referência , Software
7.
Mol Immunol ; 37(9): 515-26, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11163401

RESUMO

CD40-mediated interactions play an important role in the response to infections, transplantation, and cancer by affecting the development, activation, proliferation and differentiation of a variety of immune cells. In the current study we examined the role of CD40-mediated interactions in immune responses to bladder, pancreatic and breast carcinomas as well as melanoma cell lines using soluble human CD40L (rhCD40L) or anti-CD40 mAb in vitro. CD40 expression was readily detected in a large proportion of the cell lines and was augmented but not induced de novo by treatment with IFNgamma. Treatment of CD40-positive cell lines with rhCD40L or anti-CD40mAb enhanced cell surface expression of ICAM-1 and FAS and stimulated the production of IL-6, IL-8, GROalpha, GM-CSF and TNFalpha but not IL-4, IL-10, TGFbeta, MCP-1, RANTES, MIP-1beta, or IP-10. In addition, incubation of CD40+ tumour cell lines with immobilised rhCD40L or anti-CD40 mAb in vitro resulted in significant inhibition of proliferation and a corresponding decrease in viability. This CD40-mediated inhibition of cell growth was due, at least in part, to alterations in cell cycle and the induction of apoptosis. Transfection of CD40-negative tumour cell lines with the cDNA for CD40 conferred responsiveness to rhCD40L and anti-CD40 antibody. Finally, the presence of CD40 on the surface of carcinoma lines was found to be an important factor in the generation of tumour-specific T cell responses.


Assuntos
Neoplasias da Mama/imunologia , Antígenos CD40/imunologia , Ligante de CD40/imunologia , Melanoma/imunologia , Neoplasias Pancreáticas/imunologia , Neoplasias da Bexiga Urinária/imunologia , Células 3T3 , Animais , Anticorpos Monoclonais/imunologia , Apoptose/imunologia , Antígenos CD40/biossíntese , Ciclo Celular , Divisão Celular , Citocinas/biossíntese , Proteína Ligante Fas , Humanos , Molécula 1 de Adesão Intercelular/biossíntese , Interferon gama/imunologia , Interferon gama/farmacologia , Isoantígenos/imunologia , Células K562 , Glicoproteínas de Membrana/biossíntese , Camundongos , Células Tumorais Cultivadas , Receptor fas/biossíntese
8.
Cytokines Cell Mol Ther ; 6(3): 127-34, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11140881

RESUMO

The transfer of genes encoding co-stimulatory molecules and/or cytokines to leukaemia cells in order to create autologous tumour vaccines represents a potential immunotherapeutic strategy for treating acute myeloid leukaemia (AML). One of the essential requirements for this strategy if it is to be applicable in a clinical setting is a high efficiency of gene transfer to primary human AML blasts. Using green fluorescent protein (GFP) as a reporter gene, we have systematically evaluated a variety of physical, chemical and viral vector-based gene transfection systems in order to determine which gave the highest gene transfer efficiency to myeloid leukaemia cell lines and primary AML blasts. Transfection efficiency was low for all the physical and chemical transfection methods tested. Retroviral vector-based infection gave a high efficiency of gene transduction in two of the four leukaemia cell lines (KG1a and U937), but was low in primary AML blasts. An adenoviral vector gave a high transduction efficiency in all of the leukaemia cell lines with the exception of the HL60. In primary AML blasts, derived from 19 patients, gene transduction efficiency was variable, ranging from 1.1% to 67.1% (mean 12.1%). Following culture in cytokines GM-CSF/IL-4/CD40L, which induced differentiation of AML blasts to dendritic-like cells, transduction efficiency was increased between two- and eightfold in 6 out of the 15 cases that underwent differentiation.


Assuntos
Técnicas de Transferência de Genes , Leucemia Mieloide Aguda/terapia , Adenoviridae/genética , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Morte Celular , Diferenciação Celular , Células Dendríticas/patologia , Genes Reporter , Vetores Genéticos , Proteínas de Fluorescência Verde , Células HL-60 , Humanos , Imunoterapia , Técnicas In Vitro , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/patologia , Proteínas Luminescentes/genética , Teste de Cultura Mista de Linfócitos , Vírus da Leucemia Murina de Moloney/genética , Células Tumorais Cultivadas
9.
Immunotechnology ; 4(1): 37-47, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9661813

RESUMO

BACKGROUND: Pooled human anti-Rhesus D antiserum is currently administered for the prevention of RhD alloimmunization. Increased demand, and decreased supply, of donated pooled antiserum has led to the investigation of the suitability of human monoclonal anti-RhD antibodies for use in its place. However, it is unclear which biological properties of monoclonal antibodies are important for function in RhD-positive foetal red cell clearance and the prevention of alloimmunization. Various antibodies behave differently in a number of in vitro assays of biological function. OBJECTIVES: To compare the function and structure of two human anti-RhD IgG1 monoclonal antibodies which differ in their ability to promote red cell lysis in vitro. In particular to examine whether the functional differences correlate to differences in the IgG1 heavy chain constant region (allotype). STUDY DESIGN: We report here the cloning, characterization and re-expression in stable myeloma cell transformants of cDNAs coding for two such antibodies, secreted by the heterohybridoma cell lines ESD-1 (THERAD 03) and LHM 70/45.3 (THERAD 06). The cDNAs were then recombined to exchange portions of the Fc encoding regions and the recombinant antibodies were assayed in vitro to determine RhD-positive red cell-dependent activity. RESULTS: Recombinant THERAD 03 and 06 antibodies behaved identically to the parent antibodies. The 'inactive' THERAD 06 did not have biological activity reconstituted by exchange with the THERAD 03 Fc regions, nor was THERAD 03 activity abolished by the reciprocal Fc region exchange. CONCLUSIONS: Human monoclonal anti-RhD antibodies can be cloned and re-expressed in stable cell lines, and exhibit identical properties to the parent antibodies. Differences in biological activity cannot be attributed to differences in IgG1 heavy chain allotype.


Assuntos
Anticorpos Monoclonais/imunologia , Alótipos de Imunoglobulina/imunologia , Imunoglobulina G/imunologia , Cadeias Pesadas de Imunoglobulinas/imunologia , Isotipos de Imunoglobulinas/imunologia , Sistema do Grupo Sanguíneo Rh-Hr/imunologia , Anticorpos Monoclonais/análise , Anticorpos Monoclonais/genética , Sequência de Bases , Linhagem Celular/metabolismo , Clonagem Molecular , DNA Complementar/análise , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Leves de Imunoglobulina/genética , Cadeias Leves de Imunoglobulina/imunologia , Dados de Sequência Molecular , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia
11.
EMBO J ; 16(14): 4448-55, 1997 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-9250689

RESUMO

I factors are members of the LINE-like family of transposable elements and move by reverse transcription of an RNA intermediate. Complete I factors contain two open reading frames. The amino acid sequence encoded by the first of these, ORF1, includes the motif CX2CX4HX4C that is characteristic of the nucleocapsid domain of retroviral gag polypeptides followed by a copy of the slightly different sequences CX2CX4HX6C and CX2CX9HX6C. The function of this protein is unknown. We have expressed this protein in Escherichia coli and Spodoptera frugiperda cells and have shown that it binds both DNA and RNA but without any evidence for sequence specificity. The properties of deletion derivatives of the protein indicate that more than one region is responsible for DNA binding and that the CCHC motif is not essential for this. The ORF1 protein expressed in either E. coli or Spodoptera cells forms high molecular weight structures that require the region of the protein including the CCHC motif for their formation. This protein can also accelerate the annealing of complementary single-stranded oligonucleotides. These results suggest that this protein may associate with the RNA transposition intermediates of the I factor to form particles that enter the nucleus during transposition and that it may stimulate both the priming of reverse transcription and integration. This may be generally true for the product of the first open reading frame of LINE-like elements.


Assuntos
Elementos de DNA Transponíveis/genética , Proteínas de Ligação a DNA/genética , Drosophila melanogaster/genética , Proteínas de Ligação a RNA/genética , Animais , Reagentes de Ligações Cruzadas/metabolismo , Proteínas de Ligação a DNA/metabolismo , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Glutaral/metabolismo , Peso Molecular , Nucleocapsídeo/genética , Nucleocapsídeo/metabolismo , Fases de Leitura Aberta , Proteínas de Ligação a RNA/metabolismo , Proteínas Recombinantes/metabolismo , Deleção de Sequência , Spodoptera/genética
12.
Biochem Biophys Res Commun ; 219(1): 64-9, 1996 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-8619829

RESUMO

The Mus musculus alpha 1-protease inhibitor gene cluster encodes five highly related proteins. The most significant amino acid polymorphisms lie within the reactive-site loop which is important in determining serpin substrate specificity. All five genes are transcribed in M. musculus adult liver and presumably secreted into plasma. In an attempt to characterize their protein products all five cDNAs were expressed in recombinant mammalian cells and the protease inhibition activity of each determined. Only two of the proteins were efficient inhibitors of neutrophil elastase, the major physiological target of the sole human alpha 1-protease inhibitor (antitrypsin). Four of the proteins were active against chymotrypsin, while no substrate could be identified for the fifth.


Assuntos
Expressão Gênica , Fígado/metabolismo , Proteínas Recombinantes/biossíntese , alfa 1-Antitripsina/biossíntese , alfa 1-Antitripsina/farmacologia , Sequência de Aminoácidos , Animais , Células CHO , Linhagem Celular , Chlorocebus aethiops , Quimotripsina/antagonistas & inibidores , Cricetinae , Humanos , Rim , Elastase de Leucócito/antagonistas & inibidores , Camundongos , Dados de Sequência Molecular , Elastase Pancreática/antagonistas & inibidores , Plasmídeos , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Especificidade por Substrato , Transfecção , Tripsina/metabolismo , alfa 1-Antitripsina/isolamento & purificação
13.
Appl Microbiol Biotechnol ; 40(5): 691-8, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7764427

RESUMO

A variety of approaches to maximizing the production of recombinant human alpha 1-antitrypsin (AAT) in Chinese hamster ovary (CHO) cells have been investigated. The highly active and inducible human cytomegalovirus immediate early (IE) promoter/enhancer was used to drive transcription of a recombinant AAT gene in transiently transfected and stably transformed CHO cells. The AAT gene was modified to incorporate highly efficient 3'RNA processing signals from the herpes simplex virus type 2 IE gene 5, and optimal translational initiation signals were created by site-directed mutagenesis. The effect of flanking the recombinant gene with matrix attachment regions was investigated. Combinations of these modifications allowed secretion of up to 44 micrograms AAT/ml per day by cell lines growing in serum-rich medium. This could be increased to up to 100 micrograms AAT/ml per day upon chemical induction of expression by propionate, butyrate or hexamethylene bisacetamide. Cell lines adapted to grow in protein-free medium produced less AAT but still responded to chemical induction to secrete up to 14 micrograms/ml per day of readily purified AAT.


Assuntos
alfa 1-Antitripsina/biossíntese , alfa 1-Antitripsina/genética , Animais , Sequência de Bases , Biotecnologia , Butiratos/farmacologia , Ácido Butírico , Células CHO/efeitos dos fármacos , Células CHO/metabolismo , Linhagem Celular Transformada , Cricetinae , DNA/genética , Dimetil Sulfóxido/farmacologia , Expressão Gênica/efeitos dos fármacos , Vetores Genéticos , Humanos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Plasmídeos , Propionatos/farmacologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Transformação Genética
14.
Nucleic Acids Res ; 19(21): 5877-82, 1991 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-1834995

RESUMO

In eukaryotes splicing of pre-mRNAs is mediated by the spliceosome, a dynamic complex of small nuclear ribonucleoprotein particles (snRNPs) that associate transiently during spliceosome assembly and the splicing reaction. We have purified snRNPs from nuclear extracts of Drosophila cells by affinity chromatography with an antibody specific for the trimethylguanosine (m3G) cap structure of snRNAs U1-U5. The polypeptide components of Drosophila snRNPs have been characterized and shown to consist of a number of proteins shared by all the snRNPs, and some proteins which appear to be specific to individual snRNP particles. On the basis of their apparent molecular weight and antigenicity many of these common and particle specific Drosophila snRNP proteins are remarkably conserved between Drosophila and human spliceosomes. By probing western blots of the Drosophila snRNP polypeptides with a number of antisera raised against human snRNP proteins, Drosophila polypeptides equivalent to many of the HeLa snRNP-common proteins have been identified, as well as candidates for a number of U1, U2 and U5-specific proteins.


Assuntos
Drosophila melanogaster/química , Nucleoproteínas/análise , Ribonucleoproteínas/química , Animais , Anticorpos Monoclonais , Sequência de Bases , Western Blotting , Centrifugação com Gradiente de Concentração , Cromatografia de Afinidade , Células HeLa/química , Humanos , Dados de Sequência Molecular , Nucleoproteínas/química , Capuzes de RNA/análise , Capuzes de RNA/isolamento & purificação , Ribonucleoproteínas/isolamento & purificação , Ribonucleoproteínas Nucleares Pequenas
15.
Nucleic Acids Res ; 18(15): 4579-85, 1990 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-2167472

RESUMO

Herpes simplex virus type 1 expresses five immediate-early (IE) polypeptides. In the absence of functional Vmw175 (the product of IE gene 3) activation of transcription of later classes of viral genes and repression of IE gene expression does not occur. The recognition of specific DNA sequences by Vmw175 requires, as determined by sensitivity to mutation, a part of the protein highly conserved in the corresponding proteins of related herpes viruses. However, mutations in other parts of the protein can also disrupt specific DNA binding. This paper shows that the DNA binding domain of Vmw175 can be liberated as a functional unit by digestion with proteinase K. Analysis of mutant Vmw175 proteins showed that the proteinase K resistant domain has an amino terminus between amino acid residues 229 and 292, while its carboxy terminus is between residues 495 and 518. Mutations outside this region which affect DNA binding by the intact protein do not eliminate binding of the proteinase K resistant domain. This implies that direct DNA binding by Vmw175 involves a linear subsection of the polypeptide, and that mutations in other parts of the polypeptide which affect DNA binding of the whole protein do so by indirect means.


Assuntos
DNA Viral/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação Viral da Expressão Gênica , Simplexvirus/genética , Fatores de Transcrição/metabolismo , Endopeptidase K , Células HeLa , Humanos , Mutação , Serina Endopeptidases/metabolismo
16.
J Gen Virol ; 71 ( Pt 8): 1775-83, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2167931

RESUMO

Herpes simplex virus type 1 (HSV-1) encodes five immediate early (IE) genes of which at least three are involved in the transcriptional regulation of later classes of viral genes. Perhaps the most important of these regulatory proteins is Vmw175, a nuclear phosphoprotein of 1298 predicted amino acid residues. In the absence of functional Vmw175 the virus fails to activate early or late genes or to repress IE gene expression. All viruses of the sub-family alphaherpes-virinae encode polypeptides that are closely related to Vmw175. Mutational studies have shown that regions of homology within this family of gene regulators are generally of functional importance. One of the most striking conserved stretches of amino acid sequence is a run of serine residues followed by a highly acidic region in the amino-terminal fifth of the polypeptide. We have constructed an HSV-1 virus which lacks this serine-rich run within Vmw175. Surprisingly, the virus was viable in tissue culture cells and expressed apparently normal amounts of viral polypeptides. In plaque assays it was very slightly temperature-sensitive and, depending on the state of the host cells, could generate plaques with a syncytial morphology. The mutant protein was able to bind to DNA in a manner indistinguishable from that of the wild-type polypeptide. We conclude that despite its conservation in all of the alphaherpes-virinae so far sequenced, the serine-rich homology is not important for virus growth in tissue culture.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas Imediatamente Precoces , Serina , Simplexvirus/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Virais/metabolismo , Proteínas Virais Reguladoras e Acessórias/metabolismo , Sequência de Aminoácidos , Linhagem Celular , Clonagem Molecular , Proteínas de Ligação a DNA/genética , Regulação Viral da Expressão Gênica , Dados de Sequência Molecular , Mutação , Mapeamento por Restrição , Homologia de Sequência do Ácido Nucleico , Simplexvirus/genética , Simplexvirus/crescimento & desenvolvimento , Fatores de Transcrição/genética , Ensaio de Placa Viral , Proteínas Virais/genética , Proteínas Virais Reguladoras e Acessórias/genética
17.
J Gen Virol ; 71 ( Pt 4): 851-61, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2157798

RESUMO

Vmw175, the product of herpes simplex virus type 1 immediate early (IE) gene 3, is essential for viral replication. It is required for the activation of transcription from both early and late gene promoters and also for the repression of IE gene expression. Vmw175 is able to bind specifically to certain DNA sequences, some of which (including that at the cap site of IE gene 3) contain the consensus sequence ATCGTC. The presence of this sequence at the cap site has been correlated with the ability of Vmw175 to autoregulate its own promoter. This report describes the characterization of five viruses with temperature-sensitive (ts) lesions in Vmw175. Four of these mutants express Vmw175 which is ts in its ability to bind to DNA in vitro and to autoregulate IE-3 gene expression in the infected cell. Although Vmw175 produced by the remaining mutant, ts1225, fails to autoregulate IE-3 expression at the non-permissive temperature (NPT) its DNA-binding properties are indistinguishable from those of the wild-type protein. This suggests that the ability of Vmw175 to bind to the IE-3 cap site (as measured in vitro) is insufficient for autoregulation (in vivo). All five newly characterized ts mutants are partially permissive for early gene transcription at the NPT, although Vmw175 expressed by four of them is unable to bind to the IE-3 cap site sequence at elevated temperatures. This suggests that binding to one class of recognition sequences by Vmw175, as measured in vitro, is not absolutely required for the activation of early gene promoters during virus infection. The lesions in these five ts mutants lie in the carboxy-terminal third of the polypeptide; three of the mutations (those in ts1219, ts1221 and ts1225) were identified by DNA sequence analysis and were found to affect amino acid residues that are conserved in the homologous proteins from varicella-zoster virus and pseudorabies virus.


Assuntos
DNA Viral/genética , Regulação Viral da Expressão Gênica , Proteínas Imediatamente Precoces , Regiões Promotoras Genéticas , Simplexvirus/genética , Proteínas Virais/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Análise Mutacional de DNA , DNA Viral/biossíntese , DNA Viral/metabolismo , Proteínas de Ligação a DNA/análise , Dados de Sequência Molecular , Mutação , Mapeamento por Restrição , Temperatura , Transcrição Gênica , Ubiquitina-Proteína Ligases , Proteínas Virais/metabolismo
18.
Mol Gen Genet ; 216(2-3): 475-83, 1989 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2546042

RESUMO

The DnaA protein of Escherichia coli, essential for initiation at oriC, binds at a defined sequence which occurs at the chromosomal origin, near plasmid replication origins and in the promoters of the dnaA and mioC genes. This sequence also occurs at many other sites on the E. coli chromosome including three sites within the essential cell division genes ftsQ and A. Using an fts-lac fusion phage, lambda JFL100, we show here that fts gene expression responds both to reduced and increased intracellular levels of DnaA protein in a manner consistent with the hypothesis that DnaA protein regulates fts gene expression. Experiments using dnaC and dnaB-ts strains, however, suggest that DnaA control of fts transcription may be indirect, at least in part, with fts responding to the rate of initiation at oriC as well as to changes in DnaA protein level per se. It differs in this respect from dnaA gene expression which is unaffected when initiation of replication is inhibited by DnaB or DnaC inactivation. Strains integratively suppressed with pKN500 behave anomalously; neither fts nor dnaA transcription is significantly increased when DnaA is inactivated in these strains.


Assuntos
Proteínas de Bactérias/metabolismo , Genes Bacterianos , Transcrição Gênica , Proteínas de Bactérias/genética , Bacteriófago lambda/genética , Divisão Celular , Clonagem Molecular , Replicação do DNA , Escherichia coli/citologia , Escherichia coli/genética , Escherichia coli/metabolismo , Regulação da Expressão Gênica , Regiões Promotoras Genéticas , Supressão Genética
19.
Nucleic Acids Res ; 16(23): 11005-25, 1988 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-2849757

RESUMO

The immediate-early (IE) protein Vmw175 (ICP4) of HSV-1 is required for the transcription of later classes of viral genes and the repression of IE gene expression. We have previously constructed a panel of plasmid-borne insertion and deletion mutants of the gene encoding Vmw175 and assayed their ability to regulate transcription in transient transfection assays. By this approach we have mapped the regions of the Vmw175 amino acid sequence that are required for transcriptional activation and repression of herpes virus promoters. This paper describes the use of nuclear extracts, made from cells transfected with these mutant plasmids, in gel retardation DNA binding assays in order to define the regions of Vmw175 involved in binding to a specific Vmw175 DNA binding site. The results show that amino acid residues 275-495 (a region which is highly conserved between Vmw175 and the varicella-zoster virus "IE" 140K protein) include structures which are critically required for specific DNA binding, transactivation and repression. This raises the interesting paradox that although the specific DNA sequence recognized by Vmw175 is not commonly found in its target promoters, the protein domain required for recognition of this sequence is required for promoter activation.


Assuntos
DNA Viral/genética , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Simplexvirus/genética , Transcrição Gênica , Proteínas Virais/genética , Deleção Cromossômica , Elementos de DNA Transponíveis , Proteínas de Ligação a DNA/isolamento & purificação , Células HeLa , Humanos , Mutação , Capuzes de RNA , Mapeamento por Restrição , Transfecção
20.
Virology ; 166(1): 186-96, 1988 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2842944

RESUMO

Vmw175 is one of five immediate-early (IE) proteins encoded by herpes simplex virus type-1 (HSV-1). It is required for the transcription of later classes of genes and for the accompanying repression of IE expression. Vmw175 has been shown to be a transactivator of transcription and also to autoregulate its own synthesis. We have made a large number of small, in-frame, insertion and deletion mutants of a plasmid-borne copy of the gene encoding Vmw175. Study of the activity of the resultant mutant polypeptides in transient transfection assays has defined the regions of the protein important for the repression of its own promoter, and for the transactivation of an HSV early promoter in synergy with another HSV IE protein, Vmw110. Large stretches of the protein are relatively unimportant for either function, while the regions most sensitive to disruption correlate to sequences conserved between Vmw175 and VZV 140K, the corresponding transactivating protein of Varicella-Zoster virus. The region from amino acids 275 to 490 is particularly important for both repression and transactivation, whereas that from around 840 to 1100 seems to be more important for transactivation than repression. The nuclear localization signal has been mapped to within residues 682-774.


Assuntos
Regulação da Expressão Gênica , Proteínas Repressoras/genética , Simplexvirus/genética , Fatores de Transcrição/genética , Transcrição Gênica , Proteínas Virais/genética , Animais , Deleção Cromossômica , Análise Mutacional de DNA , Células HeLa , Células Vero , Proteínas do Envelope Viral/genética
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