Search results for "Flow Cytometry"
showing 10 items of 814 documents
Impact of MHC class I alleles on the M. tuberculosis antigen-specific CD8+ T-cell response in patients with pulmonary tuberculosis
2007
Challenged by scattered understanding of protective immunity to Mycobacterium tuberculosis (MTB), we have mapped peptide epitopes to human leukocyte antigen (HLA)-A*0101, A*0201, A*1101, A*2402, B*0702, B*0801 and B*1501 of the secreted mycobacterial antigen Ag85B, a vaccine candidate that may be associated with immune protection. Affinity (ED(50)) and half-life (t(1/2), off-rate) analysis for individual peptide species on HLA-A and HLA-B molecules revealed binding ranges between 10(-3) and 10(-7) M. After selection of the best matches, major histocompatibility complex class I/peptide tetramer complexes were constructed to measure the CD8+ T-cell responses directly ex vivo in peripheral blo…
CD4-mediated functional activation of human CD4+CD25+ regulatory T cells
2007
Naturally occurring CD4(+)CD25(+)FoxP3(+) regulatory T cells (CD25(+) Tregs) constitute a specialized population of T cells that is essential for the maintenance of peripheral self-tolerance. The immune regulatory function of CD25(+) Tregs depends upon their activation. We found that anti-CD4 antibodies activate the suppressive function of human CD25(+) Tregs in a dose-dependent manner. We demonstrate that CD4-activated CD25(+) Tregs suppress the proliferation of CD4(+) and CD8(+) T cells, their IL-2 and IFN-gamma production as well as the capacity of CD8(+) T cells to re-express CD25. By contrast, anti-CD4 stimulation did not induce suppressive activity in conventional CD4(+) T cells. Thes…
Serological identification of HSP105 as a novel non-Hodgkin lymphoma therapeutic target.
2011
Abstract We reported that the clinical efficacy of dendritic cell–based vaccination is strongly associated with immunologic responses in relapsed B-cell non-Hodgkin lymphoma (B-NHL) patients. We have now investigated whether postvaccination antibodies from responders recognize novel shared NHL-restricted antigens. Immunohistochemistry and flow cytometry showed that they cross-react with allogeneic B-NHLs at significantly higher levels than their matched prevaccination samples or nonresponders' antibodies. Western blot analysis of DOHH-2 lymphoma proteome revealed a sharp band migrating at approximately 100 to 110 kDa only with postvaccine repertoires from responders. Mass spectrometry ident…
Binding of human fibronectin to Aspergillus fumigatus conidia.
1996
Aspergillus fumigatus conidia exhibited the ability to bind purified human fibronectin, whereas mycelial forms did not bind the ligand, as detected by an indirect immunofluorescence assay with an antifibronectin polyclonal antibody after incubation of the cells with fibronectin. Flow cytometry confirmed that binding of the ligand to conidia was dose dependent and saturable. Pretreatment of the cells with trypsin markedly reduced binding, which suggested a protein nature for the binding sites present at the surface of conidia. Intact conidia were also able to adhere to fibronectin or antifibronectin antibodies, a significant reduction (from 88 to 92%) in the binding of conidia was noticed, t…
Binding of extracellular matrix proteins to Aspergillus fumigatus conidia
1996
As detected by confocal immunofluorescence microscopy, binding of fibronectin and laminin appeared to be associated with the protrusions present on the outer cell wall layer of resting Aspergillus fumigatus conidia. Flow cytometry confirmed that binding of laminin to conidia was dose dependent and saturable. Laminin binding was virtually eliminated in trypsin-treated organisms, thus suggesting the protein nature of the binding site. Conidia were also able to specifically adhere to laminin immobilized on microtiter plates. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting (immunoblotting) with laminin and antilaminin antibody of whole conidial homogenates allowed…
A central role for Notch in effector CD8(+) T cell differentiation.
2014
Activated CD8(+) T cells choose between terminal effector cell (TEC) or memory precursor cell (MPC) fates. We found that the signaling receptor Notch controls this 'choice'. Notch promoted the differentiation of immediately protective TECs and was correspondingly required for the clearance of acute infection with influenza virus. Notch activated a major portion of the TEC-specific gene-expression program and suppressed the MPC-specific program. Expression of Notch was induced on naive CD8(+) T cells by inflammatory mediators and interleukin 2 (IL-2) via pathways dependent on the metabolic checkpoint kinase mTOR and the transcription factor T-bet. These pathways were subsequently amplified d…
Human macrophages simultaneously express membrane-C1q and Fc-receptors for IgG
2005
Membrane C1q (mC1q) of macrophages (MPhi) is a precursor of the IgG-binding serum protein C1q. Thus, mC1q potentially provides one of several Fcgamma binding sites of mature MPhi and we analyzed whether simultaneous expression occurs of established receptors for IgG, FcgammaRI, II, and III, and mC1q during in vitro differentiation of MPhi. Using flow cytometry, immunoprecipitation combined with Western blotting and Northern blot analysis mC1q was hardly detected in freshly isolated blood monocytes, but increasingly in developing monocyte-derived MPhi. Laser scanning fluorescence microscopy confirmed the membrane localization of mC1q. Two-color-staining flow cytometry experiments indicated t…
Cell surface display of rat invariant γ chain: detection by monoclonal antibodies directed against a C-terminal γ chain segment
1992
A series of 14 monoclonal antibodies (mAb) directed against the C-terminal part of the rat invariant gamma chain (amino acid 142-216) was generated using distinct fusion proteins that contain this gamma segment for immunization and hybridoma screening. Additional fusion protein were prepared carrying discrete regions of the gamma chain. Employing these reagents confirmed that the obtained mAb do indeed recognize the C-terminal portion of the invariant chain, as demonstrated by Western blot analysis. All mAb established recognize epitopes present on the native gamma chain, as revealed by immunoprecipitation analysis using nonionic detergent extracts of metabolically labeled Lewis rat splenoc…
Dissecting the factors controlling seed development in the model legume Medicago truncatula
2012
Legumes are not only indispensible for sustainable agriculture but are also a rich source of protein in food and feed for humans and animals, respectively. However, major proteins stored in legume seeds are poor in sulfur-containing amino acids, and may be accompanied by anti-nutritional factors causing low protein digestibility problems. In this regard, Medicago truncatula serves as a model legume to study legume seed development especially the phase of seed storage protein accumulation. As developing legume seeds are complex structures, a thorough knowledge of the morphogenesis of the seed and the characterization of regulatory mechanisms underlying the embryo development and seed filling…
Benign, preinvasive and invasive ductal breast lesions. A comparative study with quantitative techniques: morphometry, image- and flow cytometry.
1999
The histological distinction between ductal hyperplasia of the breast, atypical ductal hyperplasia and ductal carcinoma in situ is difficult and subjective. To gain a better understanding of these lesions, we performed a comparative study comprising 20 cases of ductal hyperplasia without atypia, 20 cases of ductal hyperplasia with atypia, and 30 cases of ductal carcinoma in situ (well-, moderately- and poorly-differentiated), using quantitative techniques: image cytometry analysis, morphometry and DNA analysis, and DNA flow cytometry. Our results confirm that the mean nuclear area and volume progressively decreased from ductal carcinoma in situ to ductal hyperplasia without atypia. The diff…