Závěrečná zpráva o řešení grantu Interní grantové agentury MZ ČR
Přeruš. str. : il. ; 31 cm
Flow cytometry is currently seen as one of the most fruitful methods in hematology. CLIP ? Cytometry lab has been examining the surface molecules of the childhood acute lymphoblastic leukemia (ALL) since 1997. Based on the results provided by our lab thepatients are divided into prognostic groups and our findings also serve to choose the best treatment protocol for every individual. The importance of aberrant and asynchronous antigens for the prognosis of ALL has been the main focus of our lab for a significant time. Here the prime goal is to test the implications of the aberrant antigens in the biological behavior of the cells of childhood ALL and their potential in the leukemogenesis or chemotherapy resistance. ALL cells are signally dependent on their microenvironment, as proved by their typical localization in the bone marrow, thus we intend to apply a technique of cocultivation of the leukemic lymphoblasts on the stromal feeder layer that mimics in vitro the microenvironment of the bone marrow.
Průtoková cytometrie je v současné době považována za jednu z nejpřínosnějších metodik v hematologii. V Laboratoři CLIP-Cytometrie se již od roku 1997 zabýváme molekulární imunologií dětských akutních lymfoblastických leukémií (ALL). Výsledky našeho vyšetřování jsou používány pro zařazení pacientů do prognostických skupin a k volbě vhodného léčebného protokolu. Význam aberantně a asynchronně exprimovaných antigenů pro prognózu dětských leukémií je rovněž dlouhodobě sledovanou problematikou. Navrhovaný projekt bude testovat význam aberantně exprimovaných molekul pro biologické chování buněk dětské ALL a možné zapojení těchto molekul v procesu leukemogeneze či rezistence k chemoterapii. Protože jsou ALL buňky signálně závislé na svém mikroprostředí, o čemž svědčí typické lokalizace v kostní dřeni, využijeme ke studiu model kokultivace leukemických lymfoblastů na vrstvě stromálních buněk, které in vitro částečně nahrazují mikroprostředí kostní dřeně.
The expression of drebrin, a cytoskeletal protein newly estimated by expression profiling to correlate with the genotype and prognosis of B-cell precursor acute lymphoblastic leukemia (BCP-ALL), was examined by independent methods. After demonstrating its higher expression in TEL/AML1(pos) BCP-ALL by quantitative reverse transcriptase polymerase chain reaction, we developed an anti-drebrin monoclonal antibody (mAb). In a cohort of 86 children with BCP-ALL, we found increased expression of drebrin in TEL/AML1(pos) ALL. In conclusion, relationship of drebrin expression and prognosis or genotype can now be assessed using flow cytometry.
- MeSH
- akutní nemoc MeSH
- fúzní onkogenní proteiny MeSH
- lidé MeSH
- messenger RNA genetika MeSH
- monoklonální protilátky imunologie MeSH
- myši MeSH
- neuropeptidy imunologie metabolismus MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- pre-B-buněčná leukemie genetika imunologie metabolismus MeSH
- prognóza MeSH
- protein PEBP2A2 MeSH
- průtoková cytometrie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Engagement of the FcepsilonRI in mast cells and basophils leads to a rapid tyrosine phosphorylation of the transmembrane adaptors LAT (linker for activation of T cells) and NTAL (non-T cell activation linker, also called LAB or LAT2). NTAL regulates activation of mast cells by a mechanism, which is incompletely understood. Here we report properties of rat basophilic leukemia cells with enhanced or reduced NTAL expression. Overexpression of NTAL led to changes in cell morphology, enhanced formation of actin filaments and inhibition of the FcepsilonRI-induced tyrosine phosphorylation of the FcepsilonRI subunits, Syk kinase and LAT and all downstream activation events, including calcium and secretory responses. In contrast, reduced expression of NTAL had little effect on early FcepsilonRI-induced signaling events but inhibited calcium mobilization and secretory response. Calcium response was also repressed in Ag-activated cells defective in Grb2, a major target of phosphorylated NTAL. Unexpectedly, in cells stimulated with thapsigargin, an inhibitor of the endoplasmic reticulum Ca(2+) ATPase, the amount of cellular NTAL directly correlated with the uptake of extracellular calcium even though no enhanced tyrosine phosphorylation of NTAL was observed. The combined data indicate that NTAL regulates FcepsilonRI-mediated signaling at multiple steps and by different mechanisms. At early stages NTAL interferes with tyrosine phosphorylation of several substrates and formation of signaling assemblies, whereas at later stages it regulates the activity of store-operated calcium channels through a distinct mechanism independent of enhanced NTAL tyrosine phosphorylation.
- MeSH
- adaptorové proteiny signální transdukční metabolismus MeSH
- antigeny CD98 - lehké řetězce fyziologie MeSH
- financování organizované MeSH
- fosforylace MeSH
- intracelulární tekutina metabolismus MeSH
- krysa rodu rattus MeSH
- mastocyty imunologie metabolismus MeSH
- molekulární sekvence - údaje MeSH
- nádorové buněčné linie MeSH
- receptory IgE fyziologie MeSH
- sekvence aminokyselin MeSH
- transportní systém aminokyselin y+ fyziologie MeSH
- tyrosin metabolismus MeSH
- vápník metabolismus MeSH
- vápníková signalizace imunologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- srovnávací studie MeSH
Mast cells and basophils are major effector cells in the immunoglobulin E (IgE)-dependent allergic reactions as well as in the innate immunity. They are distributed throughout the body and, upon allergen exposure, are stimulated via the high affinity IgE receptor (FcepsilonRI) to release several pro-inflammatory mediators such as leukotrienes, immunoregulatory cytokines and histamine. FcepsilonRI-mediated signaling is initiated by tyrosine phosphorylation of FcepsilonRI subunits by Src family kinase Lyn, which is followed by an activation of Syk/Zap family kinase Syk. The activated kinases then in turn phosphorylate and activate other enzymes [phospholipase Cgamma (PLCgamma) isoforms, phosphatidylinositol-3 kinase (PI3K) isoforms, protein kinase C (PKC) isoforms, Bruton's tyrosine kinase (Btk) and others], adaptors [linker for activation of T cells (LAT), Cbl, Grb2 and others] and GTP exchange factors/GTPases (Vav, Ras, Rho, and others), and subsequently induce the mobilization of stored and extracellular Ca(2+). These and other biochemical events lead within seconds and minutes to the secretory response and later to the production of chemokines. This review is focused on the use of tyrosine kinase inhibitors specific for Src family kinases (PP1/PP2, SU6656 and CT5269), Syk kinase (piceatannol, ER-27319 and BAY 61-3606) and Btk (terreic acid and LFM-A13) for a modulation of FcepsilonRI-mediated signaling in mast cells. Potential use of the inhibitors in the treatment of inflammatory and allergy diseases as well as future directions in the development of highly specific tyrosine kinases inhibitors of new generations and their use in an intended modulation of mast cell signaling are discussed.
- MeSH
- alergie farmakoterapie imunologie MeSH
- inhibitory enzymů metabolismus terapeutické užití MeSH
- lidé MeSH
- receptory IgE fyziologie metabolismus MeSH
- signální transdukce imunologie účinky léků MeSH
- tyrosinkinasy antagonisté a inhibitory metabolismus MeSH
- zánět farmakoterapie imunologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
