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1.

001-es BibID:BIBFORM046289
Első szerző:Bacsó Zsolt (biofizikus)
Cím:A photobleaching energy transfer analysis of CD8MHC-I and LFA-1ICAM-1 interactions in CTL-target cell conjugates / Bacsó Zsolt, Bene László, Bodnár Andrea, Matkó János, Damjanovich Sándor
Dátum:1996
ISSN:0165-2478
Megjegyzések:The photobleaching energy transfer (pbFRET) technique is a fluorescence method to measure proximity relationships between molecules, especially cell surface proteins, labeled with fluorophore-conjugated monoclonal antibodies, on a pixel-by-pixel base using digital imaging microscopy. This technique enables analysis of inter- and intramolecular proximities at cell surfaces at physiological conditions. We have developed a pbFRET approach to measure intercellular proximities in order to access spatial organization of interacting proteins in the contact region of two 'communicating' cells. Two examples, as possible application areas of this approach, are presented here: interaction between CD8 and MHC-I molecules in point contacts and interaction between LFA-1 and ICAM-1 molecules in focal contacts of CTL-target conjugates. The geometry of these protein contacts based on our resonance energy transfer (RET) data is consistent with the observed blocking effects of monoclonal antibodies (directed against the interacting proteins) on the cytolytic activity of CTLs and suggest a critical role for CD8beta-subunit in signal transmission in peripheral T-lymphocytes
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Immunology Letters. - 54 : 2-3 (1996), p. 151-156. -
További szerzők:Bene László (1963-) (biofizikus) Dóczy-Bodnár Andrea (1970-) (biofizikus) Matkó János (1952-) (biológus) Damjanovich Sándor (1936-2017) (biofizikus)
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2.

001-es BibID:BIBFORM046086
Első szerző:Dóczy-Bodnár Andrea (biofizikus)
Cím:Class I HLA oligomerization at the surface of B cells is controlled by exogenous [béta]2-microglobulin : implications in activation of cytotoxic T lymphocytes / Bodnar A., Bacso Z., Jenei A., Jovin T. M., Edidin M., Damjanovich S., Matko J.
Dátum:2003
ISSN:1460-2377
Megjegyzések:Submicroscopic molecular clusters (oligomers) of class I HLA have been detected by physical techniques [e.g. fluorescence resonance energy transfer (FRET) and single particle tracking of molecular diffusion] at the surface of various activated and transformed human cells, including B lymphocytes. Here, the sensitivity of this homotypic association to exogenous beta(2)-microglobulin (beta(2)m) and the role of free heavy chains (FHC) in class I HLA oligomerization were investigated on a B lymphoblastoid cell line, JY. Scanning near-field optical microscopy and FRET data both demonstrated that FHC and class I HLA heterodimers are co-clustered at the cell surface. Culturing the cells with excess beta(2)m resulted in a reduced co-clustering and decreased molecular homotypic association, as assessed by FRET. The decreased HLA clustering on JY target cells (antigen-presenting cells) was accompanied with their reduced susceptibility to specific lysis by allospecific CD8(+) cytotoxic T lymphocytes (CTL). JY B cells with reduced HLA clustering also provoked significantly weaker T cell activation signals, such as lower expression of CD69 activation marker and lower magnitude of TCR down-regulation, than did the untreated B cells. These results together suggest that the actual level of beta(2)m available at the cell surface can control CTL activation and the subsequent cytotoxic effector function through regulation of the homotypic HLA-I association. This might be especially important in some inflammatory and autoimmune diseases where elevated serum beta(2)m levels are reported.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:International Immunology. - 15 : 3 (2003), p. 331-339. -
További szerzők:Bacsó Zsolt (1963-) (biofizikus) Jenei Attila (1966-) (biofizikus) Jovin, Thomas M. Edidin, Michael Damjanovich Sándor (1936-2017) (biofizikus) Matkó János (1952-) (biológus)
Pályázati támogatás:T034393
OTKA
T030411
OTKA
F034487
OTKA
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3.

001-es BibID:BIBFORM046291
Első szerző:Dóczy-Bodnár Andrea (biofizikus)
Cím:Modification of membrane cholesterol level affects expression and clustering of class I HLA molecules at the surface of JY human lymphoblasts / Bodnár Andrea, Jenei Attila, Bene László, Damjanovich Sándor, Matkó János
Dátum:1996
ISSN:0165-2478
Megjegyzések:Recently we have found that class I HLA molecules, key elements of the antigen presentation system for CD8 + effector cells, show a clustered lateral distribution (homoassociation) at the surface of activated human T- and B-lymphocytes as well as virus-transformed T- and B-lymphoblasts, in contrast to a disperse distribution on resting human PBLs (Matk6 et al. (1994) J. Immunol. 152, 3353; Bene et al. (1994) Eur. J. Immunol. 24, 2115). Expression of beta2m-free HLA heavy chains and exogenous beta2m have been shown as potential regulation factors of HLA-I clustering, which in turn may affect cytotoxic activity of CD8+ effector cells. Here we report a study on the effect of plasma membrane-modification (by exogenous cholesterol and phosphatidylcholine) on the expression of free HLA heavy chains and beta2m-bound HLA-I molecules on JY human B-lymphoblasts. The modulating effect of these two treatments on the lipid fluidity of cells was demonstrated by fluorescence anisotropy of DPH lipid probe. The lateral clustering (association) of HLA-I molecules was detected by flow cytometric fluorescence resonance energy transfer (FCET) and digital imaging microscopic photobleaching energy transfer (pbFRET) methods, using flourescein-isothiocyanate (FITC) (donor)- and tetramethyl-rhodamine-isothiocyanate (TRITC) (acceptor)-labeled W6/32 or KE2 antibodies directed against intact HLA-I molecules. Cholesterol enrichment of the plasma membrane increased membrane fluidity and reduced the expression of heavy- and light-chain determinants of HLA-I molecules and free heavy chains (FHCs). This was accompanied with a higher degree of HLA-I clustering as shown by the enhanced intermolecular energy transfer efficiency. In contrast, cholesterol depletion resulted in membrane fluidization and increased expression of HLA-I epitopes. Our results suggest that both cholesterol level and lipid structure/fluidity of the plasma membrane in lymphoblastoid cells may also potentially regulate lateral organization and consequently the presentation efficiency of HLA-I molecules.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Immunology Letters. - 54 : 2-3 (1996), p. 221-226. -
További szerzők:Jenei Attila (1966-) (biofizikus) Bene László (1963-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus) Matkó János (1952-) (biológus)
Pályázati támogatás:T6163
OTKA
6221
OTKA
17592
OTKA
F020102
OTKA
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4.

001-es BibID:BIBFORM039514
Első szerző:Matkó János (biológus)
Cím:GPI-microdomains (membrane rafts) and signaling of the multi-chain interleukin-2 receptor in human lymphoma/leukemia T cell lines / Matko, J., Bodnar, A., Vereb, G., Bene, L., Vamosi, G., Szentesi, G., Szollosi, J., Gaspar, R., Horejsi, V., Waldmann, T. A., Damjanovich, S.
Dátum:2002
ISSN:0014-2956
Megjegyzések:Subunits (alpha, beta and gamma) of the interleukin-2 receptor complex (IL-2R) are involved in both proliferative and activation-induced cell death (AICD) signaling of T cells. In addition, the signaling beta and gamma chains are shared by other cytokines (e.g. IL-7, IL-9, IL-15). However, the molecular mechanisms responsible for recruiting/sorting the alpha chains to the signaling chains at the cell surface are not clear. Here we show, in four cell lines of human adult T cell lymphoma/leukemia origin, that the three IL-2R subunits are compartmented together with HLA glycoproteins and CD48 molecules in the plasma membrane, by means of fluorescence resonance energy transfer (FRET), confocal microscopy and immuno-biochemical techniques. In addition to the beta and gamma(c) chains constitutively expressed in detergent-resistant membrane fractions (DRMs) of T cells, IL-2Ralpha (CD25) was also found in DRMs, independently of its ligand-occupation. Association of CD25 with rafts was also confirmed by its colocalization with GM-1 ganglioside. Depletion of membrane cholesterol using methyl-beta-cyclodextrin substantially reduced co-clustering of CD25 with CD48 and HLA-DR, as well as the IL-2 stimulated tyrosine-phosphorylation of STATs (signal transducer and activator of transcription). These data indicate a GPI-microdomain (raft)-assisted recruitment of CD25 to the vicinity of the signaling beta and gamma(c) chains. Rafts may promote rapid formation of a high affinity IL-2R complex, even at low levels of IL-2 stimulus, and may also form a platform for the regulation of IL-2 induced signals by GPI-proteins (e.g. CD48). Based on these data, the integrity of these GPI-microdomains seems critical in signal transduction through the IL-2R complex.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:European Journal Of Biochemistry. - 269 : 4 (2002), p. 1199-1208. -
További szerzők:Dóczy-Bodnár Andrea (1970-) (biofizikus) Vereb György (1965-) (biofizikus, orvos) Bene László (1963-) (biofizikus) Vámosi György (1967-) (biofizikus) Szentesi Gergely (1976-) (kémia-fizika tanár) Szöllősi János (1953-) (biofizikus) Gáspár Rezső (1944-) (biofizikus) Horejsi, Václav Waldmann, Thomas A. Damjanovich Sándor (1936-2017) (biofizikus)
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5.

001-es BibID:BIBFORM023551
Első szerző:Matkó János (biológus)
Cím:Lipid and protein mobility in the plasma membrane of cells : studies by fluorescence anisotropy and fluorescence photobleaching recovery (FPR) / Matkó János, Vereb György, Bodnár Andrea
Dátum:1998
Tárgyszavak:Orvostudományok Elméleti orvostudományok könyvfejezet
fluorescence spectroscopy
plasma membrane
mobility
fluorescence anisotropy
FRAP
Megjelenés:Practical guide to physical analysis of cell surface receptors / ed. Krasznai Zoltán, Mátyus László. - p. 92-109.
További szerzők:Vereb György (1965-) (biofizikus, orvos) Dóczy-Bodnár Andrea (1970-) (biofizikus)
Borító:

6.

001-es BibID:BIBFORM023492
Első szerző:Matkó János (biológus)
Cím:Analysis of cell surface molecular distributions and cellular signaling by flow cytometry / J. Matkó, L. Mátyus, J. Szöllősi, L. Bene, A. Jenei, P. Nagy, A. Bodnár, S. Damjanovich
Dátum:1994
ISSN:1053-0509
Megjegyzések:Flow cytometry is a fast analysis and separation method for large cell populations, based on collection and processing of optical signals gained on a cell-by-cell basis. These optical signals are scattered light and fluorescence. Owing to its unique potential ofStatistical data analysis and sensitive monitoring of (micro)heterogeneities in large cell populations, flow cytometry?in combination with microscopic imaging techniques?is a powerful tool to study molecular details of cellular signal transduction processes as well. The method also has a widespread clinical application, mostly in analysis of lymphocyte subpopulations for diagnostic (or research) purposes in diseases related to the immune system. A special application of flow cytometry is the mapping of molecular interactions (proximity relationships between membrane proteins) at the cell surface, on a cell-by-cell basis. We developed two approaches to study such questions; both are based ondistance-dependent quenching of excited state fluorophores (donors) by fluorescent or dark (nitroxide radical) acceptors via Förstertype dipole-dipole resonance energy transfer (FRET) and long-range electron transfer (LRET) mechanisms, respectively. A critical evaluation of these methods using donor- or acceptor-conjugated monoclonal antibodies (or their Fab fragments) to select the appropriate cell surface receptor or antigen will be presented in comparison with other approaches for similar purposes. The applicability of FRET and LRET for two-dimensional antigen mapping as well as for detection of conformational changes in extracellular domains of membrane-bound proteins is discussed and illustrated by examples of several lymphoma cell lines. Another special application area of flow cytometry is the analysis of different aspects of cellular signal transduction, e.g., changes of intracellular ion (Ca2+, H+, Na+) concentrations, regulation of ion channel activities, or more complex physiological responses of cell to external stimuli via correlated fluorescence and scatter signal analysis, on a cell-by-cell basis. This way different signaling events such as changes in membrane permeability, membrane potential, cell size and shape, ion distribution, cell density, chromatin structure, etc., can be easily and quickly monitored over large cell populations with the advantage of revealing microheterogeneities in the cellular responses. Flow cytometry also offers the possibility to follow the kinetics of slow (minute- and hour-scale) biological processes in cell populations. These applications are illustrated by the example of complex flow cytometric analysis of signaling in extracellular ATP-triggered apoptosis (programmed cell death) of murine thymic lymphocytes.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
fluorescence
flow cytometry
energy transfer
electron transfer
protein-protein interaction
signal transduction
egyetemen (Magyarországon) készült közlemény
Megjelenés:Journal Of Fluorescence 4 : 4 (1994), p. 303-314. -
További szerzők:Mátyus László (1956-) (biofizikus) Szöllősi János (1953-) (biofizikus) Bene László (1963-) (biofizikus) Jenei Attila (1966-) (biofizikus) Nagy Péter (1971-) (biofizikus) Dóczy-Bodnár Andrea (1970-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus)
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7.

001-es BibID:BIBFORM004716
Első szerző:Penyige András (molekuláris genetikus)
Cím:Depolarization of the membrane potential by beta-lactams as a signal to induce autolysis / Penyige, A., Matko, J., Deak, E., Bodnar, A., Barabas, G.
Dátum:2002
Megjegyzések:The effect of beta-lactam antibiotics that are known to inhibit cell wall biosynthesis and induce cell wall autolysis on the electrophysiological state of the plasma membrane in Streptomyces griseus was studied. Addition of various beta-lactam antibiotics induced a dose- and growth-stage-dependent depolarization of the membrane potential of Streptomyces griseus. The hydrolyzed biologically inactive derivative penicilloic acid had no depolarizing effect on the membrane potential. The ionophore gramicidin D, while depolarizing the membrane potential, also induced a dose-dependent increase in cell wall lysis. These observations suggest that alteration of the transmembrane potential could be an important signal in triggering cell wall autolysis of S. griseus.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Anti-Bacterial Agents
Antibiotics
Autolysis
biosynthesis
Carbocyanines
Cefotaxime
Coloring Agents
drug effects
Drug Interactions
Gramicidin
Hungary
Ionophores
Membrane Potentials
metabolism
Penicillin G
pharmacology
Research
Streptomyces
Streptomyces griseus
Support
Megjelenés:Biochemical and Biophysical Research Communications. - 290 : 4 (2002), p. 1169-1175. -
További szerzők:Matkó János (1952-) (biológus) Deák Eleonóra Dóczy-Bodnár Andrea (1970-) (biofizikus) Barabás György (1933-) (sejtbiológus, molekuláris genetikus)
Internet cím:elektronikus változat
DOI
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8.

001-es BibID:BIBFORM004886
Első szerző:Szentesi Gergely (kémia-fizika tanár)
Cím:Computer program for analyzing donor photobleaching FRET image series / Szentesi, G., Vereb, G., Horvath, G., Bodnar, A., Fabian, A., Matko, J., Gaspar, R., Damjanovich, S., Matyus, L., Jenei, A.
Dátum:2005
ISSN:1552-4922
Megjegyzések:The photobleaching fluorescence resonance energy transfer (pbFRET) technique is a spectroscopic method to measure proximity relations between fluorescently labeled macromolecules using digital imaging microscopy. To calculate the energy transfer values one has to determine the bleaching time constants in pixel-by-pixel fashion from the image series recorded on the donor-only and donor and acceptor double-labeled samples. Because of the large number of pixels and the time-consuming calculations, this procedure should be assisted by powerful image data processing software. There is no commercially available software that is able to fulfill these requirements. METHODS: New evaluation software was developed to analyze pbFRET data for Windows platform in National Instrument LabVIEW 6.1. This development environment contains a mathematical virtual instrument package, in which the Levenberg-Marquardt routine is also included. As a reference experiment, FRET efficiency between the two chains (beta2-microglobulin and heavy chain) of major histocompatibility complex (MHC) class I glycoproteins and FRET between MHC I and MHC II molecules were determined in the plasma membrane of JY, human B lymphoma cells. RESULTS: The bleaching time constants calculated on pixel-by-pixel basis can be displayed as a color-coded map or as a histogram from raw image format. CONCLUSION: In this report we introduce a new version of pbFRET analysis and data processing software that is able to generate a full analysis pattern of donor photobleaching image series under various conditions.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Algorithms
analysis
beta 2-Microglobulin
Biophysics
Cell Line,Tumor
Cells
Energy Transfer
Fluorescence
Fluorescence Resonance Energy Transfer
Glycoproteins
Histocompatibility Antigens
Human
Humans
Hungary
Lymphoma
Major Histocompatibility Complex
metabolism
methods
Microscopy
Photobleaching
Research
Software
Support
egyetemen (Magyarországon) készült közlemény
Megjelenés:Cytometry. Part A. - 67 : 2 (2005), p. 119-128. -
További szerzők:Vereb György (1965-) (biofizikus, orvos) Horváth Gábor (1974-) (biofizikus) Dóczy-Bodnár Andrea (1970-) (biofizikus) Fábián Ákos István (1982-) (aneszteziológus) Matkó János (1952-) (biológus) Gáspár Rezső (1944-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus) Mátyus László (1956-) (biofizikus) Jenei Attila (1966-) (biofizikus)
Internet cím:elektronikus változat
DOI
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