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001-es BibID:	BIBFORM004858
Első szerző:	Bene László (biofizikus)
Cím:	Detection of receptor trimers on the cell surface by flow cytometric fluorescence energy homotransfer measurements / László Bene, János Szöllősi, Gergely Szentesi, László Damjanovich, Rezső Gaspar, Thomas A. Waldmann, Sándor Damjanovich
Dátum:	2005
ISSN:	0006-3002
Megjegyzések:	Fluorescence energy homotransfer offers a powerful tool for the investigation of the state of oligomerization of cell surface receptors on a cell-by-cell basis by measuring the polarized components of fluorescence intensity of cells labeled with fluorescently stained antibodies. Here we describe homotransfer-based methods for the flow cytometric detection and analysis of hetero- and homo-associations of cell surface receptors. Homotransfer efficiencies for two- and three-body energy transfer interactions are defined and their frequency distribution curves are computed from the fluorescence anisotropy distributions of multiple-labeled cells. The fractions of receptors involved in homo-clustering is calculated based on the dependence of the fluorescence anisotropy on the surface concentration of the fluorescently stained antibodies. A homotransfer analysis of the homo- and hetero-clustering of the MHCI and MHCII glycoproteins, the cytokine receptor IL-2Ralpha, transferrin receptor and the receptor-type tyrosine phosphatase CD45 on JY B and Kit-225-K6 T cells is presented. We investigated how various factors such as the type of dye, rotational mobility of the dye and dye-targeting antibody, as well as the wavelength of the exciting light affect the homotransfer. We show that the homotransfer technique combined with the high statistical resolution of flow cytometry is an effective tool for detecting different oligomeric states of receptors by using fluorophores having restricted rotational mobility on the time scale of fluorescence
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Fluorescence anisotropy Receptor clustering MHCI and MHCII glycoprotein IL-2Rα Transferrin receptor CD45
Megjelenés:	Biochimica et Biophysica Acta (BBA). Molecular Cell Research. - 1744 : 2 (2005), p. 176-198. -
További szerzők:	Szöllősi János (1953-) (biofizikus) Szentesi Gergely (1976-) (kémia-fizika tanár) Damjanovich László (1960-) (általános sebész) Gáspár Rezső (1944-) (biofizikus) Waldmann, Thomas A. Damjanovich Sándor (1936-2017) (biofizikus)
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI
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001-es BibID:	BIBFORM042654
035-os BibID:	(scopus)19444380683 (wos)000229353200007
Első szerző:	Horváth Gábor (biofizikus)
Cím:	Selecting the right fluorophores and flow cytometer for fluorescence resonance energy transfer measurements / Gábor Horváth, Miklós Petrás, Gergely Szentesi, Ákos Fábián, John W. Park, György Vereb, János Szöllősi
Dátum:	2005
ISSN:	1552-4922 1552-4930
Megjegyzések:	BACKGROUND:Fluorescence resonance energy transfer applied in flow cytometry (FCET) is an excellent tool for determining supramolecular organization of biomolecules at the cell surface or inside the cell. Availability of new fluorophores and cytometers requires the establishment of fluorophore dye pairs most suitable for FCET measurements.METHODS:A gastric tumor cell line (N87) was labeled for major histocompatibility complex class I heavy chain and beta2-microglobulin with antibodies conjugated with fluorescein- and indocarbocyanine-like fluorophores and analyzed in FCET measurements on a cell-by-cell basis using three flow cytometers: FACSCalibur, FACSDiVa, and FACSArray.RESULTS:Normalized fluorescence intensity values were measured and normalized energy transfer efficiencies, spectral overlap integrals, and crucial dye- and instrument-dependent parameters were calculated for all matching pairs of seven fluorophores on the three commercial cytometers. The most crucial parameter in determining the applicability of the donor-acceptor pairs was the normalized fluorescence intensity and the least important one was the spectral overlap.CONCLUSIONS:On the basis of available laser lines, the optimal dye pair for all three cytometers is the Alexa546-Alexa647 pair, which produces high energy transfer efficiency values and has the best spectral characteristics with regard to laser excitation, detection of emission, and spectral overlap.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk fluorescence resonance energy transfer flow cytometry donor-acceptor pair egyetemen (magyarországon) készült közlemény
Megjelenés:	Cytometry. Part A. - 65A : 2 (2005), p. 148-157. -
További szerzők:	Petrás Miklós (1977-) (orvos) Szentesi Gergely (1976-) (kémia-fizika tanár) Fábián Ákos István (1982-) (aneszteziológus) Park, John W. Vereb György (1965-) (biofizikus, orvos) Szöllősi János (1953-) (biofizikus)
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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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001-es BibID:	BIBFORM004846
035-os BibID:	(scopus)3242784810 (wos)000223353700003
Első szerző:	Szentesi Gergely (kémia-fizika tanár)
Cím:	Computer program for determining fluorescence resonance energy transfer efficiency from flow cytometric data on a cell-by-cell basis / Szentesi, G., Horvath, G., Bori, I., Vamosi, G., Szollosi, J., Gaspar, R., Damjanovich, S., Jenei, A., Matyus, L.
Dátum:	2004
Megjegyzések:	The determination of fluorescence resonance energy transfer (FRET) with flow cytometry (FCET) is one of the most efficient tools to study the proximity relationships of cell membrane components in cell populations on a cell-by-cell basis. Because of the high amount of data and the relatively tedious calculations, this procedure should be assisted by powerful data processing software. The currently available programs are not able to fulfill this requirement. We developed a Windows-based program to calculate fluorescence resonance energy transfer efficiency values from list mode flow cytometry standard (FCS) files. This program displays the measured data in standard plots by generating one- and two-parameter histograms on linear or logarithmic scales. A graphical gating tool allows the user to select the desired cell population according to any combination of the parameter values. The program performs several statistical calculations, including mean, S.D., percent of the gated data. We have implemented two types of data sheet for FRET calculations to aid and guide the user during the analysis: one with population-mean-based autofluorescence correction and the other with spectrum-based cell-by-cell autofluorescence correction. In this paper, we describe the gating algorithms, the file opening procedure and the rules of gating. The structure of the program and a short description of the graphical user-interface (GUI) are also presented in this article.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Algorithms analysis Biophysics Cell Membrane Computer Simulation Energy Transfer Flow Cytometry Fluorescence Fluorescence Resonance Energy Transfer Humans Hungary methods Research Software Support egyetemen (Magyarországon) készült közlemény
Megjelenés:	Computer Methods and Programs in Biomedicine. - 75 : 3 (2004), p. 201-211. -
További szerzők:	Horváth Gábor (1974-) (biofizikus) Bori Imre (1929-2004) Vámosi György (1967-) (biofizikus) Szöllősi János (1953-) (biofizikus) Gáspár Rezső (1944-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus) Jenei Attila (1966-) (biofizikus) Mátyus László (1956-) (biofizikus)
Internet cím:	elektronikus változat DOI
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