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71.
Lack of CD27-CD45RA-V gamma 9V delta 2+ T cell effectors in immunocompromised hosts and during active pulmonary tuberculosis. 总被引:5,自引:0,他引:5
Cristiana Gioia Chiara Agrati Rita Casetti Cristiana Cairo Giovanna Borsellino Luca Battistini Giorgio Mancino Delia Goletti Vittorio Colizzi Leopoldo P Pucillo Fabrizio Poccia 《Journal of immunology (Baltimore, Md. : 1950)》2002,168(3):1484-1489
In humans, the circulating pool of mycobacteria-reactive Vgamma9Vdelta2+ T cells is expanded with age and may contribute to Mycobacterium tuberculosis immunosurveillance. We observed that two subsets of Vgamma9Vdelta2+ T cells could be identified on the basis of CD27 expression in immunocompetent adults, showing that functionally differentiated gammadelta T cells have lost CD27 expression. In contrast, the CD27-CD45RA-Vgamma9Vdelta2+ T cell subset of effector cells was absent in cord blood cells from healthy newborns and lacking in the peripheral blood from HIV-infected patients. Moreover, circulating Vgamma9Vdelta2+ T cell effectors were significantly reduced in patients with acute pulmonary tuberculosis, resulting in a reduced frequency of IFN-gamma-producing cells after stimulation with nonpeptidic mycobacterial ligands. These observations indicate that monitoring and boosting gammadelta T cell effectors could be clinically relevant both in immunocompromised hosts and during active tuberculosis disease. 相似文献
72.
Patrizia Casaline Delia Mezzanzanica Olga Valota Elena Adobati Antonella Tomassetti Maria I. Colnaghi Silvana Canevari 《Journal of cellular biochemistry》1995,58(1):47-55
The monoclonal antibody MOv19 directed to a folate binding protein shows temperature-dependent potentiation of binding of the noncompeting monoclonal antibody MOv18 to the relevant antigen, but the mechanism involved in this phinomenon had remained unclear. Use of chimeric versions of both monoclonal antibodies and the F(ab′)2 and fan fragments of MOv19 revealed an increment in MOv18 binding in all combinations irrespective of the orgin of the Fc portin of the monoclonal antibody. The potentiating effect of bivalent MOv19 fragments on 125l-MOv18 binding was similar to that of the entire monoclonal antibody and occurred at saturating concentrations of both reagents at which monovalent binding prevails. Similarly, the monovalent fragment also induced a significant increase in MOv18 bunding. Howener, the potentiation sccurred only at very high concentrations of antibody fragment. Homologous inhibition was drastically reduced using MOv19 Fab fragment, suggesting a low binding stability of the monovalent reagent. Immunoblotting analysis and binding in the presence of exogenous purified folate binding protein indicated a cross-linking between soluble and cell surface molecules mediated by the bivalent monoclonal antibodies. The extentof the increase in MOv18 binging at O°C with high amounts of exogenous folate binding protein was lower than that obtained at 370C in the absence of added molecule. Release of 125l-MOv18 from the cell surface was significantly higher in the absence of MOv19 than in its presence. Affinity constant values of 125l-MOv18 binding evaluated in the presence of MOv19 or control monoclonal antibody MINT5 were comparable, whereas the number of binding sites per cell detected by 125l-MOv18 was significantly higher in the presence of MOv19 than MINT5. Together, the data suggest that monoclonal antibody MOv19 induces a conformational change of the molecule it binds that increases the number of antigenic sites anvailable for MOv18 binding and, in turn, the binding stability of the latter, MOv19 bivalency also contributes to the MOv18 binding increment by cross-linking released and cell surface–anchored folate binding protein molecules. © Wiley-Liss, Inc. 相似文献
73.
Dissociation and reconstitution of bovine seminal RNAase: Construction of a hyperactive hybrid dimer
Maurizio Tamburrini Renata Piccoli Delia Picone Alberto Di Donato Giuseppe D'Alessio 《Journal of Protein Chemistry》1989,8(6):719-731
The quaternary structure of bovine seminal ribonuclease, the only dimeric protein in the superfamily of ribonucleases, is maintained both by noncovalent forces and by two intersubunit disulfides. The available monomeric derivatives of the enzyme may not be reassembled into dimers. They are catalytically active, but do not retain certain properties of the dimeric enzyme, such as: (i) the ability to respond cooperatively to increasing substrate concentrations in the rate-limiting reaction step; and (ii) the antitumor and immunosuppressive actions. In this report we describe the preparation of stable monomers of seminal ribonuclease which can be reassociated into covalent dimers indistinguishable from the native protein. With this procedure a hybrid dimer was constructed, made up of a native subunit associated to a subunit catalytically inactivated by selective alkylation of the active site His-119. This dimer was found to have enzymic properties typical of monomeric ribonucleases, such as a hyperbolic saturation curve in the hydrolytic rate-limiting step of the reaction. However, the hybrid dimer was one order-of-magnitude more active than the dimeric enzyme. 相似文献
74.
Delia Fernández Rosa María Valencia Tibor Molnár Ana Vega Eva Sagüés 《Aerobiologia》1998,14(2-3):215-220
The spores ofAlternaria andCladosporium are present throughout the year in the atmosphere of León (NW Spain), although they show an important seasonal variation.
To understand the relationship between the number of spores and climatic factors,Alternaria andCladosporium spores counts for January 1994 to December 1995 were examined by means of correlation analyses. The results of weekly samples
of both years showed that the spores concentration of two taxa are significantly and positively correlated with maximum and
minimum temperature and sunshine hours and negatively with relative humidity. The statistical analysis of daily samples generally
showed the same results. In the hourly distribution of spore concentrations we can see a similar behaviour ofAlternaria andCladosporium, with most spores collected in the 12–14 h period. 相似文献
75.
Theodorus Eko Pramudito Delia Agustina Thi Kim Ngan Nguyen Antonius Suwanto 《Probiotics and antimicrobial proteins》2018,10(1):110-117
Bacterial antifungal cyclic lipopeptides (ACLs) have become a promising alternative to synthetic fungicide to control pathogenic fungi. Bacillus sp. is known to produce three families of ACL, namely iturin, surfactin, and fengycin. In this paper, we characterized the ACLs produced by B. methylotrophicus HC51 (referred as HC51) mainly regarding its composition and effectivity against fungal plant pathogen. HC51 culture was tested against various pathogenic fungi and the ACLs were extracted and analyzed using liquid chromatography–electrospray ionization mass spectrometry. HC51 showed strong antifungal activity against the plant pathogens Ganoderma sp. and Fusarium sp. Cell-free methanol extract of HC51 contains iturin A and various variants of fengycin. C16 fengycin A was present in four fractions which indicates it as a major component of ACL from HC51. Five variants of fengycin were detected, four of which had been previously reported. We found a novel C17 fengycin F that is characterized by a substitution of l-ornithine into lysine. Considering that l-ornithine is an important building block of fengycin, this substitution suggests the possibility of an alternative pathway for fengycin biosynthesis. 相似文献
76.
Teresa L. Dzieweczynski Amanda M. Bessler† Delia S. Shelton‡ & William J. Rowland† 《Ethology : formerly Zeitschrift fur Tierpsychologie》2006,112(2):127-133
Recent research on Siamese fighting fish, Betta splendens, and other taxa has demonstrated that an audience can cause males to alter their behavior in aggressive interactions. One factor not taken into account in these studies is how exactly the audience influences these interactions. It is possible that a live audience may interact with the subjects, creating an active communication network rather than a signaler–receiver dyad with a passive audience. Here, we used a dummy audience to control for information exchange between the audience and the interactants that might cause them to modify their behavior. Audience treatments included dummies of male and female B. splendens, a dummy cichlid, and a control condition with no audience present. The presence of a dummy audience did not influence male–male interactions. However, males spent the most time near the audience tank when the audience was a dummy of a B. splendens. This suggests that some factor other than the physical presence of the audience is responsible for the modification of behavior found in previous audience effect studies in Siamese fighting fish. However, we cannot rule out definitively that our dummy audience is viewed as unimportant by the opponents and, thus, ignored. Further research is necessary to determine which component of the audience is important for producing audience effects. 相似文献
77.
Fibroblast dynamics as an in vitro screening platform for anti‐fibrotic drugs in primary myelofibrosis 下载免费PDF全文
Ciprian Tomuleasa MD PhD Sonia Selicean MD Grigore Gafencu MD Bobe Petrushev MD Laura Pop PhD Cristian Berce PhD Anca Jurj PhD Adrian Trifa MD PhD Ana‐Maria Rosu MD Sergiu Pasca MD Lorand Magdo MD Mihnea Zdrenghea MD PhD Delia Dima MD PhD Alina Tanase MD PhD Ioana Frinc MD Anca Bojan MD Ioana Berindan‐Neagoe PhD Gabriel Ghiaur MD PhD Stefan O. Ciurea MD 《Journal of cellular physiology》2018,233(1):422-433
Although the cause for bone marrow fibrosis in patients with myelofibrosis remains controversial, it has been hypothesized that it is caused by extensive fibroblast proliferation under the influence of cytokines generated by the malignant megakaryocytes. Moreover, there is no known drug therapy which could reverse the process. We studied the fibroblasts in a novel system using the hanging drop method, evaluated whether the fibroblasts obtain from patients are part of the malignant clone of not and, using this system, we screen a large library of FDA‐approved drugs to identify potential drugs candidates that might be useful in the treatment of this disease, specifically which would inhibit fibroblast proliferation and the development of bone marrow fibrosis. We have found that the BM fibroblasts are not part of the malignant clone, as previously suspected and two immunosuppressive medications—cyclosporine and mycophenolate mophetil, as most potent suppressors of the fibroblast collagen production thus potentially inhibitors of bone marrow fibrosis production in myelofibrosis. 相似文献
78.
79.
80.
A nuclear mutant of Arabidopsis thaliana selected for enhanced sensitivity to light-chill stress is altered in PSII electron transport activity 总被引:1,自引:0,他引:1
Delia Tarantino Alberto Vianelli Luisa Carraro Carlo Soave 《Physiologia plantarum》1999,107(3):361-371
Chilling in the light imposes a considerable level of stress on the photosynthetic apparatus, resulting in a decrease of photosystem II activity and the quenching of maximum and variable fluorescence. We selected in a fah - 1 mutagenized population of Arabidopsis thaliana , which permits a direct visible evaluation of the intensity of chlorophyll (Chl) fluorescence, a monogenic recessive nuclear mutant hypersensitive to photoinhibition induced by light and cold. The major phenotypic trait of the mutant is the appearance of chlorotic areas on developed leaves. Photochemical analyses indicate that the mutant is hypersensitive to photoinhibition in excess light in the cold but also at room temperature. The susceptibility to photoinhibition is a consequence of perturbations in photochemistry already present in unstressed plants. Such perturbations result in a greater fraction of the primary acceptor QA remaining in the reduced state even at low light fluxes. From estimates of the number of total and functional PSII units and measurements of PSII quantum yield and QA − reoxidation kinetics, the basic lesion of the mutant seems restricted to PSII photochemistry likely affecting the rate of electron transport from QA − to QB . 相似文献