RESUMO
BACKGROUND: Large-cell transformation in mycosis fungoides [MF] is associated with an aggressive clinical course and poor survival. In addition to tumour progression, infectious complications may be the cause of death. We report a case of aseptic pustular dermatosis in transformed MF that very quickly became aggressive and was followed by rapid death of the patient. PATIENTS AND METHODS: A 47-year-old man presented with disseminated CD30+ transformed MF skin tumours refractory to chemotherapy for nine consecutive months. Ten days after a first course of dexamethasone, cytarabine and carboplatin, he was hospitalized for febrile neutropenia. Following this episode of neutropenia, he developed a febrile pustular rash disseminated on the tumours and on plaques, associated with marked neutrophilic leucocytosis. Bacteriological and mycological skin and blood samples were negative. Tumour biopsies showed a dermal infiltrate of CD30+ T-cells corresponding to the transformed MF, mixed with neutrophils. The pustule biopsies revealed intra-epidermal pustules and dermal-epidermal infiltration of neutrophils. The pustular eruption regressed with corticosteroids. Despite a last line of treatment with romidepsin, the patient died 6 weeks after the "neutrophilic" event. DISCUSSION: Episodes of neutrophilic dermatosis [ND] are frequently seen in haematological disease and some substances can induce a variant form of eccrine hidradenitis. However, our patient's presentation was different, without the appearance of "classic" ND but rather diffuse pustular lesions carrying a poor prognosis, which was followed by rapid death. Once the hypothesis of infectious complications has been ruled out, treatment is based on systemic corticosteroids associated with specific treatment of the lymphoma.
Assuntos
Micose Fungoide/complicações , Síndrome de Sweet/etiologia , Corticosteroides/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ciclofosfamida/administração & dosagem , Ciclofosfamida/efeitos adversos , Depsipeptídeos/uso terapêutico , Progressão da Doença , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Resistencia a Medicamentos Antineoplásicos , Evolução Fatal , Neutropenia Febril/induzido quimicamente , Neutropenia Febril/complicações , Neutropenia Febril/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Micose Fungoide/tratamento farmacológico , Invasividade Neoplásica , Neutrófilos/patologia , Pancitopenia/etiologia , Polietilenoglicóis/uso terapêutico , Prednisona/administração & dosagem , Prednisona/efeitos adversos , Síndrome de Sweet/patologia , Vincristina/administração & dosagem , Vincristina/efeitos adversosRESUMO
Reverse genetics to determine the relative importance of individual pathogenicity factors of the potato cyst nematode Globodera rostochiensis depends, apart from an efficient transformation protocol for this obligatory plant parasite, on the availability of an efficient promoter. PCR-based cloning was used to isolate a cDNA encoding glyceraldehyde-3-phosphate-dehydrogenase (GAPDH, a crucial enzyme in glycolysis and gluconeogenesis; this gene was designated gpd) and its 5'-flanking region. The cDNA includes 1047 nucleotides encoding an open reading frame that shows high homology with GAPDHs from Caenorhabditis elegans and other species. Analysis of the 745 bp 5'-flanking region of the gpd gene showed no homology with a similar region in C. elegans. In this region several eukaryotic promoter elements are present. 5' Rapid amplification of cDNA ends revealed this gene was trans-spliced with a SL1 spliced leader. The 5'-flanking region of the gpd gene was fused to green fluorescent protein reporter gene and microinjected into the gonads of C. elegans. Green fluorescent protein expression, under the transcriptional control of the 5'-flanking region of gpd, was mainly observed in body wall muscles of transgenic animals. This putative promoter region of GAPDH could be a valuable tool to drive gene expression in transgenic G. rostochiensis and other related plant-parasitic nematode species.
Assuntos
Clonagem Molecular , Gliceraldeído-3-Fosfato Desidrogenases/genética , Regiões Promotoras Genéticas , Trans-Splicing , Tylenchoidea/genética , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Sequência de Bases , Caenorhabditis elegans/genética , Ilhas de CpG , DNA Complementar , Expressão Gênica , Genes de Helmintos , Genes Reporter , Gliceraldeído-3-Fosfato Desidrogenases/química , Proteínas de Fluorescência Verde , Proteínas Luminescentes , Dados de Sequência Molecular , Proteínas Recombinantes de Fusão , TATA Box , Transformação Genética , Tylenchoidea/enzimologiaRESUMO
The genomic organization of genes encoding beta-1,4-endoglucanases (cellulases) from the plant-parasitic cyst nematodes Heterodera glycines and Globodera rostochiensis (HG-eng1, Hg-eng2, GR-eng1, and GR-eng2) was investigated. HG-eng1 and GR-eng1 both contained eight introns and structural domains of 2151 and 2492bp, respectively. HG-eng2 and GR-eng2 both contained seven introns and structural domains of 2324 and 2388bp, respectively. No significant similarity in intron sequence or size was observed between HG-eng1 and HG-eng2, whereas the opposite was true between GR-eng1 and GR-eng2. Intron positions among all four cyst nematode cellulase genes were conserved identically in relation to the predicted amino acid sequence. HG-eng1, GR-eng1, and GR-eng2 had several introns demarcated by 5'-GCellipsisAG-3' in the splice sites, and all four nematode cellulase genes had the polyadenylation and cleavage signal sequence 5'-GAUAAA-3'-both rare occurences in eukaryotic genes. The 5'- flanking regions of each nematode cellulase gene, however, had signature sequences typical of eukaryotic promoter regions, including a TATA box, bHLH-type binding sites, and putative silencer, repressor, and enhancer elements. Database searches and subsequent phylogenetic comparison of the catalytic domain of the nematode cellulases placed the nematode genes in one group, with Family 5, subfamily 2, glycosyl hydrolases from Scotobacteria and Bacilliaceae as the most homologous groups. The overall amino acid sequence identity among the four nematode cellulases was from 71 to 83%, and the amino acid sequence identity to bacterial Family 5 cellulases ranged from 33 to 44%. The eukaryotic organization of the four cyst nematode cellulases suggests that they share a common ancestor, and their strong homology to prokaryotic glycosyl hydrolases may be indicative of an ancient horizontal gene transfer.
Assuntos
Celulase/genética , Evolução Molecular , Genes de Helmintos , Nematoides/genética , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Regiões 3' não Traduzidas/genética , Regiões 5' não Traduzidas/genética , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/genética , Celulase/metabolismo , Clonagem Molecular , Sequência Consenso/genética , Éxons/genética , Hidrólise , Íntrons , Dados de Sequência Molecular , Poli A/metabolismo , Alinhamento de SequênciaRESUMO
beta-1,4-Endoglucanases (EGases, EC 3.2.1.4) degrade polysaccharides possessing beta-1,4-glucan backbones such as cellulose and xyloglucan and have been found among extremely variegated taxonomic groups. Although many animal species depend on cellulose as their main energy source, most omnivores and herbivores are unable to produce EGases endogenously. So far, all previously identified EGase genes involved in the digestive system of animals originate from symbiotic microorganisms. Here we report on the synthesis of EGases in the esophageal glands of the cyst nematodes Globodera rostochiensis and Heterodera glycines. From each of the nematode species, two cDNAs were characterized and hydrophobic cluster analysis revealed that the four catalytic domains belong to family 5 of the glycosyl hydrolases (EC 3.2.1, 3.2.2, and 3.2.3). These domains show 37-44% overall amino acid identity with EGases from the bacteria Erwinia chrysanthemi, Clostridium acetobutylicum, and Bacillus subtilis. One EGase with a bacterial type of cellulose-binding domain was identified for each nematode species. The leucine-rich hydrophobic core of the signal peptide and the presence of a polyadenylated 3' end precluded the EGases from being of bacterial origin. Cyst nematodes are obligatory plant parasites and the identified EGases presumably facilitate the intracellular migration through plant roots by partial cell wall degradation.
Assuntos
Celulase/genética , Nematoides/enzimologia , Plantas/parasitologia , Sequência de Aminoácidos , Animais , Celulase/química , Clonagem Molecular , Cistos/parasitologia , Hibridização In Situ , Dados de Sequência Molecular , Nematoides/patogenicidade , Precursores de Proteínas/genética , RNA Mensageiro/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Solubilidade , Distribuição TecidualRESUMO
ABSTRACT In preparasitic second-stage juveniles (J(2)) of potato cyst nematode Globodera rostochiensis, six proteins with molecular masses of 30, 31a/b, 32, 39, and 49 kDa were recognized on Western blots by a monoclonal antibody (MGR48) specific for the subventral esophageal glands. All of these subventral gland proteins (svp's) focused in the basic range (pI 6.8 to 8.6) of an immobilized pH gradient. Western blotting showed that the svp's were present in preparasitic and parasitic J(2) and not in later juvenile stages and adult females. Minor svp quantities also were observed in adult males. Immunogold labeling of preparasitic J(2) showed that the svp's were localized in the rough endoplasmic reticulum and secretory granules of the subventral esophageal glands. Potato root diffusate triggered the secretion of svp's through the stylet, and 5-methoxy-N,N-dimethyltryptamine-hydrogen-oxalate had only a quantitative, additional effect. The forward flow of svp's through the metacorporal pump chamber was confirmed by the presence of svp's in the circular lumen of the esophagus (procorpus), as established by immunoelectron microscopy. Our data provide conclusive evidence that secretory proteins of the subventral glands of G. rostochiensis can be secreted through the stylet and support the hypothesis that the subventral esophageal glands play an important role in the early events of this nematode-plant interaction.
RESUMO
Sodium dodecyl sulfate-extracted proteins from second-stage juveniles (J2) of the potato cyst nematode Globodera rostochiensis were fractionated by preparative continuous flow electrophoresis, and monoclonal antibodies (MAbs) were raised against the 38- to 40.5-kDa protein fraction. Screening of the hybridoma culture fluids by immunofluorescence microscopy of J2 resulted in the identification of 12 MAbs that bound specifically to the subventral esophageal glands. On Western blots of J2 these MAbs identified four protein bands with apparent molecular masses of 30, 31, 39, and 49 kDa. Immunoelectron microscopy with one of these MAbs showed an intense labeling of the electron dense core of the secretory granules in the subventral gland cells of J2. It is concluded that one or more of these proteins are localized within these secretory granules. Immunofluorescence microscopy of J2 from other plant parasitic nematode species showed that most of these MAbs also bind to the subventral glands of G. pallida and G. tabacum but not of Heterodera schachtii, H. glycines, Meloidogyne incognita, or M. hapla.
Assuntos
Anticorpos Anti-Helmínticos/imunologia , Grânulos Citoplasmáticos/química , Sistema Digestório/química , Proteínas de Helminto/isolamento & purificação , Nematoides/química , Animais , Anticorpos Monoclonais , Antígenos de Helmintos/isolamento & purificação , Western Blotting , Reações Cruzadas , Grânulos Citoplasmáticos/ultraestrutura , Sistema Digestório/ultraestrutura , Imunofluorescência , Proteínas de Helminto/imunologia , Interações Hospedeiro-Parasita , Microscopia Imunoeletrônica , Nematoides/crescimento & desenvolvimento , Nematoides/patogenicidade , Nematoides/ultraestrutura , Solanum tuberosum/parasitologia , Especificidade da Espécie , VirulênciaRESUMO
The genes for the subunits of the Fe-only hydrogenase from Desulfovibrio vulgaris are transcribed as a 1.9 kb mRNA; the operon contains no other genes besides those encoding the two subunits. The transcriptional start site of the operon was mapped. Determination of hydrogenase activity and hydrogenase mRNA levels indicates a growth-phase dependent regulation of hydrogenase expression at transcriptional level. However, it has not yet been possible to localize the sequences required for regulation and expression of the genes.
Assuntos
Desulfovibrio vulgaris/enzimologia , Desulfovibrio vulgaris/genética , Regulação Bacteriana da Expressão Gênica , Hidrogenase/genética , Óperon , RNA Bacteriano/química , Sequência de Aminoácidos , Sequência de Bases , Mapeamento Cromossômico , Indução Enzimática , Genes Bacterianos , Dados de Sequência Molecular , RNA Mensageiro/química , Análise de Sequência de RNARESUMO
The gene encoding the prismane protein from Desulfovibrio vulgaris (Hildenborough) was inserted into broad-host-range vector pSUP104. The recombinant plasmid, pJSP104, was transferred to D. vulgaris by conjugal plasmid transfer. In the transconjugant D. vulgaris cells the prismane protein was 25-fold overproduced. The overproduced prismane protein was characterized by molecular mass, isoelectric point, iron content and spectroscopical properties. Both the iron content and the ultraviolet/visible spectrum are identical to the wild-type protein indicating that iron incorporation in the overproduced protein is complete. EPR spectra of the dithionite-reduced form of the overproduced protein indicated that the Fe-S cluster might occur in a similar structure as found in inorganic model compounds containing a [6Fe-6S] prismane core. The as-isolated overproduced protein showed the presence of a second S = 1/2 spin system that was also detected in the corresponding prismane protein from D. desulfuricans (ATCC 27774), but not in the protein from wild-type D. vulgaris. This additional signal was irreversibly transformed to the 'wild-type' high-spin and low-spin systems upon two reduction/re-oxidation cycles. It is shown that the EPR spectroscopy of the overproduced prismane protein is very similar to that of the D. desulfuricans enzyme and, with the exception of the second S = 1/2 spin system, to that of the prismane protein from wild-type D. vulgaris. Contrary to claims for the D. desulfuricans protein, it is shown here that all data can be fully explained assuming a single [6Fe-6S] cluster, that might be titrated into four different redox states and occurs in up to three different spin systems in the one-electron reduced state.
Assuntos
Proteínas de Bactérias/metabolismo , Desulfovibrio vulgaris/metabolismo , Proteínas Ferro-Enxofre , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Clonagem Molecular , Conjugação Genética , Desulfovibrio vulgaris/genética , Espectroscopia de Ressonância de Spin Eletrônica , Escherichia coli/genética , Genes Bacterianos , Vetores Genéticos , Ferro/análise , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , EspectrofotometriaRESUMO
The gene encoding a protein containing a putative [6Fe-6S] prismane cluster has been cloned from Desulfovibrio vulgaris (Hildenborough) and sequenced. The gene encodes a polypeptide composed of 553 amino acids (60,161 Da). The DNA-derived amino acid sequence was partly confirmed by N-terminal sequencing of the purified protein and of fragments of the protein generated by CNBr cleavage. Furthermore, the C-terminal sequence was verified by digestion with carboxypeptidases A and B. The polypeptide contains nine Cys residues. Four of these residues are gathered in a Cys-Xaa2-Cys-Xaa7-Cys-Xaa5-Cys motif located towards the N-terminus of the protein. No relevant sequence similarity was found with other proteins, including those with high-spin Fe-S clusters (nitrogenase, hydrogenase), with one significant exception: the stretch containing the first four Cys residues spans two submotifs, Cys-Xaa2-Cys and Lys-Gly-Xaa-Cys-Gly, separated by 11 residues, that are also present in high-spin Fe-S cluster containing CO dehydrogenase. Western-blot analysis demonstrates cross-reactivity of antibodies raised against the purified protein both in Desulfovibrio strains and other sulfate-reducing bacteria. Hybridization of the cloned gene with genomic DNA of several other Desulfovibrio species indicates that homologous sequences are generally present in the genus Desulfovibrio.
Assuntos
Proteínas de Bactérias/química , Desulfovibrio vulgaris/química , Proteínas Ferro-Enxofre/química , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Sequência de Bases , Western Blotting , Clonagem Molecular , Brometo de Cianogênio , DNA Bacteriano/química , DNA Bacteriano/genética , Genes Bacterianos , Proteínas Ferro-Enxofre/genética , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fragmentos de Peptídeos/química , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie , Transcrição GênicaRESUMO
The gene encoding a protein containing a novel iron sulfur cluster ([6Fe-6S]) has been cloned from Desulfovibrio desulfuricans ATCC 27774 and sequenced. An open reading frame was found encoding a 545 amino acid protein (M(r) 58,496). The amino acid sequence is highly homologous with that of the corresponding protein from D. vulgaris (Hildenborough) and contains a Cys-motif that may be involved in coordination of the Fe-S cluster.
Assuntos
Proteínas de Bactérias/genética , Desulfovibrio/genética , Proteínas Ferro-Enxofre/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Genes Bacterianos , Dados de Sequência Molecular , Fases de Leitura Aberta , Homologia de Sequência do Ácido NucleicoRESUMO
Downstream of the genes for the structural alpha and beta subunits of the periplasmic Desulfovibrio vulgaris (Hildenborough) hydrogenase a DNA fragment was detected with sequence homology to these genes. This fragment was cloned in Escherichia coli and the nucleotide sequence was determined. A gene was detected on the fragment with coding capacity for a 65.8 kDa polypeptide, hyd gamma. The central part of hyd gamma has an unusually high degree of homology with the alpha subunit and the C-terminal part has similarity with the beta subunit. These results strongly suggest that the three genes for hyd gamma and the alpha and beta subunits derive from one common ancestor gene. We succeeded in the identification of the translational product of this gene in E. coli, but were unable to determine the function of hyd gamma after expression in E. coli.
Assuntos
Desulfovibrio/genética , Genes Bacterianos , Hidrogenase/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , DNA Bacteriano/genética , Desulfovibrio/enzimologia , Escherichia coli/genética , Dados de Sequência Molecular , PlasmídeosRESUMO
The binding of the major water-soluble lens protein alpha-crystallin to the lens plasma membrane has been investigated by reassociating purified alpha-crystallin with alpha-crystallin-depleted membranes and with phospholipid vesicles in which the lens membrane protein MP26 had been reconstituted. alpha-Crystallin reassociates at high affinity (Kd = 13 X 10(-8)M) with alkali-washed lens plasma membranes but not with lens plasma membranes treated with guanidine/HCl, nor with phospholipid vesicles or erythrocyte membranes. Binding to lens plasma membranes is dependent on salt, temperature and pH and occurs in a saturable manner. Reconstitution of MP26 into phospholipid vesicles and subsequent analysis of alpha-crystallin binding suggests the involvement of this transmembrane protein. Binding ist not influenced by pretreatment of membranes with proteases, suggesting that the 4-kDa cytoplasmic fragment of MP26 is not necessary for alpha-crystallin binding. Labeling experiments using (trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine as a probe for intrinsic membrane proteins further showed that alpha-crystallin contains hydrophobic regions on its surface which might enable this protein to make contact with the lipid bilayer. Newly synthesized alpha-crystallin, in lens culture, is not associated with the plasma membrane, suggesting that the assembly of alpha-crystallin aggregates does not take place in a membrane-bound mode.