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001-es BibID:	BIBFORM114595
035-os BibID:	(scopus)85169450797 (WOS)001058799600001
Első szerző:	Kormos József (fizikus)
Cím:	HLA DQ protein changes the cell surface distribution pattern of HLA proteins as monitored by Förster resonance energy transfer and high-resolution electron microscopy / Kormos József, Veres Adrienn J., Imre László, Mátyus László, Benkő Szilvia, Szöllősi János, Jenei Attila
Dátum:	2023
ISSN:	1552-4922 1552-4930
Megjegyzések:	Peptide presentation by MHC class I and MHC class II molecules plays important roles in the regulation of the immune response. One factor in these displays is the density of antigen, which must exceed a critical threshold for the effective activation of T cells. Nonrandom distribution of MHC class I and class II has already been detected at the nanometer level and at higher hierarchical levels. It is not clear how the absence and reappearance of some protein molecules can influence the nonrandom distribution. Therefore, we performed experiments on HLA II-deficient bare lymphocyte syndrome (BLS1) cells: we created a stable transfected cell line, tDQ6-BLS-1, and were able to detect the effect of the appearance of HLA-DQ6 molecules on the homo and heteroassociation of different cell surface molecules by comparing Förster resonance energy transfer (FRET) efficiency on transfected cells to that on nontransfected BLS-1 and JY human B-cell lines. Our FRET results show a decrease in homoassociation FRET between HLA I chains in HLA-DQ6-transfected tDQ6-BLS-1 cells compared with the parent BLS-1 cell line and an increase in heteroassociation FRET between HLA I and HLA II (compared with JY cells), suggesting a similar pattern of antigen presentation by the HLA-DQ6 allele. Transmission electron microscopy (TEM) revealed that both HLA class I and class II molecules formed clusters at higher hierarchical levels on the tDQ6-BLS-1 cells, and the de novo synthesized HLA DQ molecules did not intersperse with HLA class I islands. These observations could be important in understanding the fine tuning of the immune response.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk BLS-1 FRET HLA-DQ6 immunogold labeling MHC TEM
Megjelenés:	Cytometry Part A. - 103 : 12 (2023), p. 978-991. -
További szerzők:	Veres Adrienn J. (biofizikus) Imre László (1979-) (biológus) Mátyus László (1956-) (biofizikus) Benkő Szilvia (1973-) (molekuláris biológus) Szöllősi János (1953-) (biofizikus) Jenei Attila (1966-) (biofizikus)
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001-es BibID:	BIBFORM004566
Első szerző:	Kovács Tamás (szülész-nőgyógyász, humángenetikus)
Cím:	DNA flow cytometry of human spermatozoa : consistent stoichiometric staining of sperm DNA using a novel decondensation protocol / Kovács T., Békési G., Fábián A., Rákosy Z., Horváth G., Mátyus L., Balázs M., Jenei A.
Dátum:	2008
Megjegyzések:	Rapid flow cytometric measurement of the frequency of aneuploid human sperms is in increasing demand but development of an exploitable method is hindered by difficulties of stoichiometric staining of sperm DNA. An aggressive decondensation protocol is needed after which cell integrity still remains intact. We used flow cytometry to examine the effect of lithium diiodosalicylate (LIS, chaotropic agent) on fluorescence intensity of propidium iodide-treated human spermatozoa from 10 normozoospermic men. When flow cytometric identification of diploid spermatozoa was achieved, validation was performed after sorting by three-color FISH. In contrast with the extremely variable histograms of nondecondensed sperms, consistent identification of haploid and diploid spermatozoa was possible if samples were decondensed with LIS prior to flow cytometry. A 76-fold enrichment of diploid sperms was observed in the sorted fractions by FISH. A significant correlation was found between the proportion of sorted cells and of diploid sperms by FISH. Application of LIS during the preparation of sperm for flow cytometry appears to ensure the stoichiometric staining of sperm DNA, making quantification of aneuploid sperm percentage possible. To our knowledge this is the first report in terms of separating spermatozoa with confirmedly abnormal chromosomal content. High correlation between the proportion of cells identified as having double DNA content by flow cytometry and diploid sperm by FISH allows rapid calculation of diploidy rate. Copyright 2008 International Society for Advancement of Cytometry.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban diploid spermatozoa aneuploid spermatozoa propidium iodide lithium diiodosalicylate egyetemen (Magyarországon) készült közlemény
Megjelenés:	Cytometry. Part A 73 : 10 (2008), p. 965-970. -
További szerzők:	Békési Gyöngyi Fábián Ákos István (1982-) (aneszteziológus) Rákosy Zsuzsa (1978-) (sejtbiológus, molekuláris biológus, genetikus) Horváth Gábor (1974-) (biofizikus) Mátyus László (1956-) (biofizikus) Balázs Margit (1952-) (sejtbiológus, molekuláris genetikus) Jenei Attila (1966-) (biofizikus)
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001-es BibID:	BIBFORM046278
Első szerző:	Matkó János (biológus)
Cím:	Luminescence quenching by long range electron transfer : a probe of protein clustering and conformation at the cell surface / Matko Janos, Jenei Attila, Wei Taiyin, Edidin Michael
Dátum:	1995
ISSN:	0196-4763
Megjegyzések:	Quenching of luminescence from fluorescent and phosphorescent probes by nitroxide spin labels with a long range electron transfer (LRET) mechanism (44,45) has been tested as a tool to monitor association/clustering and conformational changes of cell surface proteins. The membrane proteins were labeled with monoclonal antibodies or Fab fragments conjugated with luminescent probes or water-soluble nitroxide spin labels. The method was tested as a probe of 3 different aspects of protein-protein association involving class I MHC molecules: (1) interaction between the heavy and light chains of the MHC molecules, (2) clustering, self-association of MHC molecules, (3) proximity of MHC molecules to transferrin receptors of fibroblasts or surface immunoglobulin molecules of B lymphoblasts. The extent of quenching upon increasing the fractional density of the quencher was sensitive for protein association in accordance with earlier immunoprecipitation and flow cytometric Forster-type energy transfer (FCET) data obtained on the same cells. These data suggest that the LRET quenching can be used as intra- or intermolecular ruler in a 0.5-2.5 nm distance range. This approach is simpler (measurements only on donor side) and faster than many other experimental techniques in screening physical association or conformational changes of membrane proteins by means of spectrofluorimetry, flow cytometry, or microscope based imaging.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Cytometry. - 19 : 3 (1995), p. 191-200. -
További szerzők:	Jenei Attila (1966-) (biofizikus) Wei, Taiyin Edidin, Michael
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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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)
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