Összesen 3 találat.


001-es BibID:BIBFORM004854
Első szerző:Andrásfalvy Márton
Cím:The beta subunit of the type I Fcepsilon receptor is a target for peptides inhibiting IgE-mediated secretory response of mast cells / Andrasfalvy, M., Peterfy, H., Toth, G., Matko, J., Abramson, J., Kerekes, K., Vamosi, G., Pecht, I., Erdei, A.
Megjegyzések:Peptides originally derived from complement component C3a were earlier shown to inhibit the type I FcepsilonR (FcepsilonRI)-mediated degranulation of mucosal type mast cells. In the present study, we show that C3a7, a peptide with a natural sequence, and its modified derivative, C3a9, are powerful inhibitors of the above response of both serosal and mucosal type mastocytes. We demonstrate that these peptides inhibit FcepsilonRI-induced membrane proximal events, suppress phosphorylation of the FcepsilonRI beta subunit, the protein tyrosine kinase Lyn, as well as the transient rise in free cytosolic Ca2+ level. The late phase of cellular response was also inhibited, as demonstrated by the reduced TNF-alpha secretion. Experiments using two independent methods provided evidence that the interaction site of complement-derived peptides is the FcepsilonRI beta-chain. This was further supported by fluorescence confocal microscopic colocalization and resonance energy transfer measurements. Taken together, these results suggest the presence of distinct "activating" and "inhibitory" motifs in the C3a sequence. Response to both is in balance under physiologic conditions. Furthermore, present data predict that such inhibitory peptides may serve as potent agents for future therapeutic intervention.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
1-Phosphatidylinositol 3-Kinase
antagonists & inhibitors
Complement C3a
Energy Transfer
Immunoglobulin E
Mast Cells
Mice,Inbred BALB C
Protein Subunits
Tumor Necrosis Factor-alpha
Megjelenés:The Journal of Immunology. - 175 : 5 (2005), p. 2801-2806. -
További szerzők:Péterfy Hajna Tóth Gábor (Szeged) Matkó János (1952-) (biológus) Abramson, Jakub Kerekes Krisztina Vámosi György (1967-) (biofizikus) Pecht, Israel Erdei Anna
Internet cím:elektronikus változat


001-es BibID:BIBFORM097487
Első szerző:Kenesei Ádám
Cím:IL-15 Trans-Presentation Is an Autonomous, Antigen-Independent Process / Kenesei Ádám, Volkó Julianna, Szalóki Nikoletta, Mocsár Gábor, Jambrovics Károly, Balajthy Zoltán, Bodnár Andrea, Tóth Katalin, Waldmann Thomas A., Vámosi György
ISSN:0022-1767 1550-6606
Megjegyzések:IL-15 plays a pivotal role in the long-term survival of T cells and immunological memory. Its receptor consists of three subunits (IL-15R?, IL-2/15R?, and ?c). IL-15 functions mainly via trans-presentation (TP), during which an APC expressing IL-15 bound to IL-15R? presents the ligand to the ??c receptor-heterodimer on a neighboring T/NK cell. To date, no direct biophysical evidence for the intercellular assembly of the IL-15R heterotrimer exists. Ag presentation (AP), the initial step of T cell activation, is also based on APC?T cell interaction. We were compelled to ask whether AP has any effect on IL-15 TP or whether they are independent processes. In our human Raji B cell?Jurkat T cell model system, we monitored inter-/intracellular protein interactions upon formation of IL-15 TP and AP receptor complexes by Förster resonance energy transfer measurements. We detected enrichment of IL-15R? and IL-2/15R? at the synapse and positive Förster resonance energy transfer efficiency if Raji cells were pretreated with IL-15, giving direct biophysical evidence for IL-15 TP. IL-15R? and MHC class II interacted and translocated jointly to the immunological synapse when either ligand was present, whereas IL-2/15R? and CD3 moved independently of each other. IL-15 TP initiated STAT5 phosphorylation in Jurkat cells, which was not further enhanced by AP. Conversely, IL-15 treatment slightly attenuated Ag-induced phosphorylation of the CD3? chain. Our studies prove that in our model system, IL-15 TP and AP can occur independently, and although AP enhances IL-15R assembly, it has no significant effect on IL-15 signaling during TP. Thus, IL-15 TP can be considered an autonomous, Ag-independent process.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Journal Of Immunology. - 207 : 10 (2021), p. 2489-2500. -
További szerzők:Volkó Julianna (1983-) (biotechnológus) Szalóki Nikoletta (1981-) (biológus) Mocsár Gábor (1981-) (biofizikus) Jambrovics Károly (1988-) (biológus, gyógyszer-biotechnológus) Balajthy Zoltán (1957-) (biokémikus, sejtbiológus) Dóczy-Bodnár Andrea (1970-) (biofizikus) Tóth Katalin Ágnes (1977-) (biokémikus, molekuláris biológus) Waldmann, Thomas A. Vámosi György (1967-) (biofizikus)
Pályázati támogatás:GINOP-2.3.2-15-2016-00026
Tempus Public Foundation 273478
Deutscher Akademischer Austauschdienst 273478
HHS | NIH | National Cancer Institute intramural research program
Internet cím:Szerző által megadott URL
Intézményi repozitóriumban (DEA) tárolt változat


001-es BibID:BIBFORM008295
Első szerző:Tóth Beáta
Cím:Transglutaminase 2 is needed for the formation of an efficient phagocyte portal in macrophages engulfing apoptotic cells / Beáta Tóth, Éva Garabuczi, Zsolt Sarang, György Vereb, György Vámosi, Daniel Aeschlimann, Bernadett Blaskó, Bálint Bécsi, Ferenc Erdődi, Adam Lacy-Hulbert, Ailiang Zhang, Laura Falsca, Raymond B. Birge, Zoltán Balajthy, Gerry Melino, László Fésüs, Zsuzsa Szondy
Megjegyzések:Transglutaminase 2 (TG2), a protein cross-linking enzyme with many additional biological functions, acts as coreceptor for integrin beta3. We have previously shown that TG2-/- mice develop an age-dependent autoimmunity due to defective in vivo clearance of apoptotic cells. Here we report that TG2 on the cell surface and in guanine nucleotide-bound form promotes phagocytosis. Besides being a binding partner for integrin beta3, a receptor known to mediate the uptake of apoptotic cells via activating Rac1, we also show that TG2 binds MFG-E8 (milk fat globulin EGF factor 8), a protein known to bridge integrin beta3 to apoptotic cells. Finally, we report that in wild-type macrophages one or two engulfing portals are formed during phagocytosis of apoptotic cells that are characterized by accumulation of integrin beta3 and Rac1. In the absence of TG2, integrin beta3 cannot properly recognize the apoptotic cells, is not accumulated in the phagocytic cup, and its signaling is impaired. As a result, the formation of the engulfing portals, as well as the portals formed, is much less efficient. We propose that TG2 has a novel function to stabilize efficient phagocytic portals.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:The Journal of Immunology 182 : 4 (2009), p. 2084-2092. -
További szerzők:Garabuczi Éva (1982-) (biokémikus, molekuláris biológus) Sarang Zsolt (1976-) (mikrobiológus) Vereb György (1965-) (biofizikus, orvos) Vámosi György (1967-) (biofizikus) Aeschlimann, Daniel Blaskó Bernadett Bécsi Bálint (1981-) (vegyészmérnök) Erdődi Ferenc (1953-) (biokémikus) Lacy-Hulbert, Adam Zhang, Ailiang Falsca, Laura Birge, Raymond B. Balajthy Zoltán (1957-) (biokémikus, sejtbiológus) Melino, Gerry Fésüs László (1947-) (orvos biokémikus) Szondy Zsuzsanna (1959-) (molekuláris sejtbiológus, biokémikus)
Internet cím:elektronikus változat
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