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001-es BibID:	BIBFORM004925
Első szerző:	Damjanovich Sándor (biofizikus)
Cím:	Structural hierarchy in the clustering of HLA class I molecules in the plasma membrane of human lymphoblastoid cells / Damjanovich, S., Vereb, G., Schaper, A., Jenei, A., Matko, J., Starink, J. P., Fox, G. Q., Arndt-Jovin, D. J., Jovin, T. M.
Dátum:	1995
Megjegyzések:	Major histocompatibility complex (MHC) class I antigens in the plasma membranes of human T (HUT-102B2) and B (JY) lymphoma cells were probed by immunochemical reagents using fluorescence, transmission electron, and scanning force microscopies. Fluorescent labels were attached to monoclonal antibodies W6/32 or KE-2 directed against the heavy chain of HLA class I (A, B, C) and L368 or HB28 against the beta 2-microglobulin light chain. The topological distribution in the nanometer range was studied by photobleaching fluorescence resonance energy transfer (pbFRET) on single cells. A nonrandom codistribution pattern of MHC class I molecules was observed over distances of 2-10 nm. A second, nonrandom, and larger-scale topological organization of the MHC class I antigens was detected by indirect immunogold labeling and imaging by transmission electron microscopy (TEM) and scanning force microscopy (SFM). Although some differences in antigen distribution between the B- and T-cell lines were detected by pbFRET, both cell lines exhibited similar clustering patterns by TEM and SFM. Such defined molecular distributions on the surfaces of cells of the immune system may reflect an underlying specialization of membrane lipid domains and fulfill important functional roles in cell-cell contacts and signal transduction.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Adult analysis beta 2-Microglobulin Cell Line Cell Membrane chemistry Energy Transfer Fluorescence Gold Colloid Histocompatibility Antigens Class I Human Immunohistochemistry immunology Light Lymphocytes Major Histocompatibility Complex methods Microscopy Microscopy,Electron Signal Transduction Support,Non-U.S.Gov't Tumor Cells,Cultured ultrastructure egyetemen (Magyarországon) készült közlemény
Megjelenés:	Proceedings of the National Academy of Sciences of the United States of America. - 92 : 4 (1995), p. 1122-1126. -
További szerzők:	Vereb György (1965-) (biofizikus, orvos) Schaper, Achim Jenei Attila (1966-) (biofizikus) Matkó János (1952-) (biológus) Starink, J. Pascual Fox, Geoffrey Q. Arndt-Jovin, Donna J. Jovin, Thomas M.
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001-es BibID:	BIBFORM004864
035-os BibID:	(scopus)26444452209 (wos)000232299300016
Első szerző:	Friedländer Elza (biofizikus)
Cím:	Signal transduction of erbB receptors in trastuzumab (Herceptin) sensitive and resistant cell lines : local stimulation using magnetic microspheres as assessed by quantitative digital microscopy / Friedlander, E., Arndt-Jovin, D. J., Nagy, P., Jovin, T. M., Szollosi, J., Vereb, G.
Dátum:	2005
ISSN:	1552-4922
Megjegyzések:	ErbB2 (HER-2), a member of the epidermal growth factor (EGF) receptor family, is a class I transmembrane receptor tyrosine kinase. Although erbB2 has no known physiologic ligand, it can form complexes with other members of the family and undergo transactivation of its very potent kinase activity, thereby initiating downstream signaling and cell proliferation. ErbB2 is a frequent pathologic marker in ductal invasive breast carcinomas and is targeted by using a specific humanized monoclonal antibody, trastuzumab (Herceptin). The antibody is effective in only 20% to 50% of erbB2-positive tumors, and this resistance, as yet poorly understood, constitutes a major therapeutic challenge. METHODS: Magnetic microspheres coated with ligands or antibodies are widely used for separation of proteins and cells and allow localized, high intensity, and precisely timed stimulation of cells. We used EGF- and trastuzumab-covered paramagnetic microspheres, quantitative confocal laser scanning microscopy, and digital image processing to investigate the (trans)activation of and local signal propagation from erbB1 and erbB2 on trastuzumab sensitive and resistant carcinoma cell lines expressing these receptors at high levels. RESULTS: On A431 cells expressing high levels of endogenous erbB1 and transfected erbB2-mYFP (A4-erbB2-mYFP F4 cell line), EGF-coupled-microspheres activated erbB1 and transactivated erbB2-mYFP. In two other cell lines with comparable erbB2 expression but lower levels of erbB1, EGF microspheres transactivated erbB2 less efficiently. Trastuzumab in solution activated erbB2 on A4-erbB2-mYFP and the trastuzumab sensitive SKBR-3 cells, but only negligibly on the resistant JIMT-1 cells that showed a 10 times higher K(d) for the antibody. Nevertheless, pronounced erbB2 activation and tyrosine phosphorylation could be detected after stimulation with trastuzumab-coupled microspheres in all cell lines, although transactivation of erbB1 was negligible. Receptor phosphorylation was restricted to the immediate proximity of the microspheres, i.e., receptor clusters external to these locations remained inactive. CONCLUSION: ErbB1 ligand and erbB2 specific antibody attached to magnetic microspheres are efficient tools in assessing erbB activation, localized signal propagation, and erbB heterodimer formation. Trastuzumab coupled to microspheres is more efficient at accessing erbB2 and activating it than trastuzumab in solution
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Animals Antibodies Antibodies,Monoclonal Biophysics Carcinoma Cell Line Cell Line,Tumor Cell Proliferation Cells chemistry drug effects Drug Resistance,Neoplasm Epidermal Growth Factor genetics Humans Hungary Ligands Magnetics metabolism methods Microscopy Microspheres pharmacology Phosphorylation Proteins Receptor,erbB-2 Research Signal Transduction Solubility Support Trans-Activation (Genetics)
Megjelenés:	Cytometry. Part A. - 67 : 2 (2005), p. 161-171. -
További szerzők:	Arndt-Jovin, Donna J. Nagy Péter (1971-) (biofizikus) Jovin, Thomas M. Szöllősi János (1953-) (biofizikus) Vereb György (1965-) (biofizikus, orvos)
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