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1.

001-es BibID:BIBFORM006036
Első szerző:Gáspár Rezső (biofizikus)
Cím:Effects of bretylium tosylate on voltage-gated potassium channels in human T lymphocytes / Gaspar, R., Panyi, G., Ypey, D. L., Krasznai, Z., Vereb, G., Pieri, C., Damjanovich, S.
Dátum:1994
Megjegyzések:Using the patch-clamp technique, we determined that bretylium tosylate, a quaternary ammonium compound possessing immunomodulating activity, decreased the whole-cell K+ current in human T lymphocytes, in a dose-dependent manner, in the 0.05-5 mM extracellular concentration range. Bretylium tosylate prolonged the recovery from inactivation and accelerated the inactivation and deactivation of the K+ current but did not influence the kinetics of activation or the voltage dependence of activation and steady state inactivation of the K+ conductance. The percentage of drug-induced block was independent of membrane potential. K+ channel block by bretylium tosylate was partially and slowly removable by washing with drug-free extracellular solution. Bovine serum albumin (10 mg/ml) in the bath lifted the drug-induced block almost instantaneously, although not completely. In control experiments bovine serum albumin increased the inactivation time constant of the K+ channels but left the peak K+ current amplitude unaffected. On the basis of the experimental evidence, a gating-dependent allosteric interaction is suggested for the mechanism of drug action. The effective dose range, time of exposure, and reversibility of bretylium tosylate-induced K+ channel block correlated well with the same parameters of the drug-induced inhibition of T lymphocyte activation. The reported effects of bretylium tosylate on T cell mitogenesis can be regarded partly as a consequence of its blocking effects on voltage-gated K+ channels.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Bretylium Tosylate
Cell Membrane
drug effects
Electrophysiology
Human
Hungary
In Vitro
Ion Channel Gating
Kinetics
Lymphocytes
pharmacology
physiology
Potassium
Potassium Channels
Support,Non-U.S.Gov't
T-Lymphocytes
Megjelenés:Molecular pharmacology. - 46 : 4 (1994), p. 762-766. -
További szerzők:Panyi György (1966-) (biofizikus) Ypey, Dirk L. Krasznai Zoltán (1950-) (biofizikus) Vereb György (1965-) (biofizikus, orvos) Pieri, Carlo Damjanovich Sándor (1936-2017) (biofizikus)
Internet cím:elektronikus változat
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2.

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)
Internet cím:Szerző által megadott URL
DOI
Intézményi repozitóriumban (DEA) tárolt változat
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3.

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
Borító:

4.

001-es BibID:BIBFORM033278
035-os BibID:PMID:8588941 WOS:A1995TF18900001
Első szerző:Vereb György (biofizikus, orvos)
Cím:Plasma-membrane-bound macromolecules are dynamically aggregated to form non-random codistribution patterns of selected functional elements. Do pattern recognition processes govern antigen presentation and intercellular interactions? / György Vereb, László Matyus, László Bene, György Panyi, Zsolt Bacsó, Margit Balázs, János Matkó, János Szöllősi, Rezső Gáspár, Sándor Damjanovich, Robert E. Dale, Carlo Pieri, Marcel Ameloot
Dátum:1995
Megjegyzések:Molecular recognition processes between cell surface elements are discussed with special reference to cell surface pattern formation of membrane-bound integral proteins. The existence, as detected by flow cytometric resonance energy transfer (Appendix), and significance of cell surface patterns involving the interleukin-2 receptor, the T-cell receptor-CD3 system, the intercellular adhesion molecule ICAM-1, and the major histocompatibility complex class I and class II molecules in the plasma membrane of lymphocytes are described. The modulation of antigen presentation by transmembrane potential changes is discussed, and a general role of transmembrane potential changes, and therefore of ion channel activities, adduced as one of the major regulatory mechanisms of cell-cell communication. A general role in the mediation and regulation of intercellular interactions is suggested for cell-surface macromolecular patterns. The dynamic pattern of protein and lipid molecules in the plasma membrane is generated by the genetic code, but has a remarkable flexibility and may be one of the major instruments of accommodation and recognition processes at the cellular level.
Tárgyszavak:Orvostudományok Egészségtudományok idegen nyelvű folyóiratközlemény külföldi lapban
cell surface
molecular pattern
energy transfer
fluorescence
flow cytometry
transmembrane potential
MHC
antigen presentation
intercellular communication
egyetemen (Magyarországon) készült közlemény
Megjelenés:Journal of Molecular Recognition. - 8 : 4 (1995), p. 237-246. -
További szerzők:Mátyus László (1956-) (biofizikus) Bene László (1963-) (biofizikus) Panyi György (1966-) (biofizikus) Bacsó Zsolt (1963-) (biofizikus) Balázs Margit (1952-) (sejtbiológus, molekuláris genetikus) Matkó János (1952-) (biológus) Szöllősi János (1953-) (biofizikus) Gáspár Rezső (1944-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus) Dale, Robert E. Pieri, Carlo Ameloot, Marcel
Internet cím:DOI
Intézményi repozitóriumban (DEA) tárolt változat
Borító:

5.

001-es BibID:BIBFORM004673
Első szerző:Vereb György (biofizikus, orvos)
Cím:Cholesterol-dependent clustering of IL-2Ralpha and its colocalization with HLA and CD48 on T lymphoma cells suggest their functional association with lipid rafts / Vereb, G., Matko, J., Vamosi, G., Ibrahim, S. M., Magyar, E., Varga, S., Szollosi, J., Jenei, A., Gaspar, R., Waldmann, T. A., Damjanovich, S.
Dátum:2000
Megjegyzések:Immunogold staining and electron microscopy show that IL-2 receptor alpha-subunits exhibit nonrandom surface distribution on human T lymphoma cells. Analysis of interparticle distances reveals that this clustering on the scale of a few hundred nanometers is independent of the presence of IL-2 and of the expression of the IL-2R beta-subunit. Clustering of IL-2Ralpha is confirmed by confocal microscopy, yielding the same average cluster size, approximately 600-800 nm, as electron microscopy. HLA class I and II and CD48 molecules also form clusters of the same size. Disruption of cholesterol-rich lipid rafts with filipin or depletion of membrane cholesterol with methyl-beta-cyclodextrin results in the blurring of cluster boundaries and an apparent dispersion of clusters for all four proteins. Interestingly, the transferrin receptor, which is thought to be located outside lipid rafts, exhibits clusters that are only 300 nm in size and are less affected by modifying the membrane cholesterol content. Furthermore, transferrin receptor clusters hardly colocalize with IL-2Ralpha, HLA, and CD48 molecules (crosscorrelation coefficient is 0.05), whereas IL-2Ralpha colocalizes with both HLA and CD48 (crosscorrelation coefficient is between 0.37 and 0.46). This coclustering is confirmed by electron microscopy. The submicron clusters of IL-2Ralpha chains and their coclustering with HLA and CD48, presumably associated with lipid rafts, could underlie the efficiency of signaling in lymphoid cells.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
analysis
Antigens,CD
Biophysics
Cells
Cholesterol
HLA Antigens
Human
Hungary
Immunohistochemistry
Interleukin-2
Lymphoma
Lymphoma,T-Cell
Membrane Fluidity
Membrane Lipids
metabolism
Microscopy
Microscopy,Confocal
Microscopy,Immunoelectron
Neoplasm Proteins
pathology
physiology
Proteins
Receptors,Interleukin-2
Support,Non-U.S.Gov't
T-Lymphocytes
Tumor Cells,Cultured
Megjelenés:Proceedings of the National Academy of Sciences of the United States of America. - 97 : 11 (2000), p. 6013-6018. -
További szerzők:Matkó János (1952-) (biológus) Vámosi György (1967-) (biofizikus) Ibrahim, Shehu M. Magyar Erika Varga Sándor (1943-) (biofizikus) Szöllősi János (1953-) (biofizikus) Jenei Attila (1966-) (biofizikus) Gáspár Rezső (1944-) (biofizikus) Waldmann, Thomas A. Damjanovich Sándor (1936-2017) (biofizikus)
Internet cím:elektronikus változat
elektronikus változat
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