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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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001-es BibID:	BIBFORM004665
035-os BibID:	(scopus)0034033048 (wos)000086686100012
Első szerző:	Hederer, Rosemarie A.
Cím:	The CD45 tyrosine phosphatase regulates Campath-1H (CD52)-induced TCR-dependent signal transduction in human T cells / Hederer, R. A., Guntermann, C., Miller, N., Nagy, P., Szollosi, J., Damjanovich, S., Hale, G., Alexander, D. R.
Dátum:	2000
Megjegyzések:	Campath-1H, a humanized mAb undergoing clinical trials for treatment of leukemia, transplantation and autoimmune diseases, produces substantial lymphocyte depletion in vivo.The antibody binds to CD52, a highly glycosylated molecule attached to the membrane by a glycosylphosphatidylinositol anchor. Cross-linked Campath-1H is known to activate T cells in vitro. We have investigated the molecular basis for these effects by comparing the protein tyrosine phosphorylation signals induced by Campath-1H and the CD3 mAb OKT3 in primary T cells, and in CD45(+)TCR(+), CD45(-)TCR(+) and CD45(+)TCR(-) Jurkat subclones transfected with CD52. Our results show that Campath-1H triggers similar tyrosine phosphorylation events as OKT3 in both primary T cells and in the CD45(+)TCR(+) Jurkat sub-clone, albeit at quantitatively lower levels. However, no phospholipase C gamma 1 activation nor calcium signals were detected in response to CD52 ligation. The CD52-mediated induction of protein tyrosine phosphorylation was absolutely dependent upon the expression of both the TCR and the CD45 phosphotyrosine phosphatase at the cell surface. Cross-linking of Campath-1H was essential for signal transduction in all cells investigated. Fluorescence resonance energy transfer was used to demonstrate CD52 homo-association at the cell surface in Jurkat T cells in a TCR- and CD45-independent manner, and CD52-TCR association in CD45(+)TCR(+) cells. We propose a model to explain the activating effects of Campath-1H in which CD52 mAb cross-linking causes the trapping of TCR polypeptides within molecular complexes at the cell surface, thereby inducing signals via the TCR by a process which depends on the CD45-mediated regulation of the p56(lck) and p59(fyn) tyrosine kinases.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Antibodies, Monoclonal Antibodies, Neoplasm Antigens, CD Antigens, CD45 Calcium Calcium Signaling Cells, Cultured Comparative Study Energy Transfer enzymology Fluorescence genetics Glycoproteins Human immunology In Vitro Inositol 1,4,5-Trisphosphate Isoenzymes Jurkat Cells metabolism Phospholipase C physiology Receptors, Antigen, T-Cell Signal Transduction Support, Non-U.S.Gov't T-Lymphocytes Transfection
Megjelenés:	International Immunology. - 12 : 4 (2000), p. 505-516. -
További szerzők:	Guntermann, Christine Miller, Nigel Nagy Péter (1971-) (biofizikus) Szöllősi János (1953-) (biofizikus) Damjanovich Sándor (1936-2017) (biofizikus) Hale, Geoffrey Alexander, Denis R.
Internet cím:	DOI elektronikus változat
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