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001-es BibID:	BIBFORM068948
Első szerző:	Antal-Szalmás Péter (laboratóriumi szakorvos)
Cím:	Diverging Pathways for Lipopolysaccharide and CD14 in Human Monocytes / Peter Antal-Szalmas, Miriam J. J. G. Poppelier, Roel Broekhuizen, Jan Verhoef, Jos A. G. van Strijp, Kok P. M. van Kessel
Dátum:	2000
ISSN:	0196-4763
Megjegyzések:	Background: CD14 is considered to be the major endotoxin(lipopolysaccharide [LPS]) binding molecule on humanmonocytes. It initiates cellular response, but its rolein the clearance of LPS is not well understood. Underconditions that ensure totally CD14-dependent LPS bindingon human monocytes, the internalization mechanismsof LPS and CD14 were studied.Methods: The uptake and intracellular distribution offluorescein isothiocyanate (FITC)-LPS and CD14 was determinedby flow cytometry, trypan blue quenching, andconfocal fluorescence microscopy. Incubation of surfacebiotinylatedcells with LPS at 37?C or 4?C and subsequentsubfractionation was used to further characterize CD14internalization. The amount of the intracellular CD14 wasestimated by CD14 enzyme-linked immunosorbent assay(ELISA).Results: The internalization rate of 10 ng/ml FITC-LPSwith 1% human serum was 1% of bound endotoxin perminute, whereas CD14 expression did not decrease at thesame time surface. We proved the presence of an intracellularCD14 pool (2.68 3 106 molecules per unstimulatedmonocyte) and could show that internalized FITCLPSmolecules can be found in different intracellularcompartments than CD14. Subfractionation of LPS-treatedbiotinylated monocytes showed no change in biotinylatedCD14 in the membrane fraction independently of theincubation temperature (37?C or at 4?C) used, indicatingthat these CD14 molecules were not taken up by an activeprocess.Conclusions: These data indicate the presence of a largeintracellular CD14 pool in monocytes with a yet unknownfunction, and suggest that LPS and CD14 molecules can beinternalized independently after association on the cellsurface.
Tárgyszavak:	Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban LPS internalization CD14
Megjelenés:	Cytometry 41 (2000), p. 279-288. -
További szerzők:	Poppelier, Miriam J. J. G Broekhuizen, Roel Verhoef, Jan Strijp, Jos A. G., van Kessel, Kok P. M., van
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM068923
Első szerző:	Antal-Szalmás Péter (laboratóriumi szakorvos)
Cím:	Spare CD14 molecules on human monocytes enhance the sensitivity for low LPS concentrations / Antal-Szalmás Péter, Poppelier Miriam J. J. G, Sümegi Andrea, van der Bruggen Tjomme, Verhoef Jan, van Kessel Kok P. M., van Strijp Jos A. G
Dátum:	2004
ISSN:	0165-2478
Megjegyzések:	Human monocytes express on their plasma membrane relatively large number of CD14 molecules, known to play a crucial role in thelipopolisaccharide (LPS)-mediated cellular activation. Indirect data (J. Biol. Chem. 270 (1995) 9904) suggest that not all of these CD14molecules participate in LPS-signaling, but the importance of these spare receptors and the exact number of CD14 involved in activation upondifferent LPS-stimuli is not known. Using different concentrations of a blocking anti-CD14 monoclonal antibody (mAb 60bca) we createdmonocytes with graded amounts of CD14. The exact number of occupied and free receptors was quantitated by flow cytometry and specialmAb-labeled standard beads. The number of free CD14 molecules per monocyte in the presence of 10, 3.33, 0.73, 0.25 and 0.041 g/mlmAb was 0, 13 100, 49 300, 97 700 and 165 900. Stimulation of these partially blocked monocytes with 0.1, 1, 10 and 100 ng/ml ReLPS inthe presence of 3% human serum revealed that already 13 100 and 97 700 CD14 molecules provided a maximal Tumor necrosis factor (TNF ) mRNA response using 100 and 10 ng/ml ReLPS, while the activation totally depended on the number of available CD14 moleculesin the case of 1 and 0.1 ng/ml ReLPS. Our data imply that the number of CD14 molecules available for LPS-binding influence the cellularresponse. In the presence of higher concentrations of LPS only fractions of CD14 participate in the cell activation, while the presence of thespare receptors enhance the sensitivity against lower LPS amounts.
Tárgyszavak:	Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban CD14
Megjelenés:	Immunology Letters 93 : 1 (2004), p. 11-15. -
További szerzők:	Poppelier, Miriam J. J. G Sümegi Andrea (1969-) (biológus) van der Bruggen, Tjomme Verhoef, Jan Kessel, Kok P. M., van Strijp, Jos A. G., van
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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