Mast cells (MCs) are long-living immune cells highly specialized in the storage and release of different biologically active compounds and are involved in the regulation of innate and adaptive immunity. MC degranulation and replacement of MC granules are accompanied by active membrane remodelling. Tetraspanins represent an evolutionary conserved family of transmembrane proteins. By interacting with lipids and other membrane and intracellular proteins, they are involved in organisation of membrane protein complexes and act as "molecular facilitators" connecting extracellular and cytoplasmic signaling elements. MCs express different tetraspanins and MC degranulation is accompanied by changes in membrane organisation. Therefore, tetraspanins are very likely involved in the regulation of MC exocytosis and membrane reorganisation after degranulation. Antiviral response and production of exosomes are further aspects of MC function characterized by dynamic changes of membrane organization. In this review, we pay a particular attention to tetraspanin gene expression in different human and murine MC populations, discuss tetraspanin involvement in regulation of key MC signaling complexes, and analyze the potential contribution of tetraspanins to MC antiviral response and exosome production. In-depth knowledge of tetraspanin-mediated molecular mechanisms involved in different aspects of the regulation of MC response will be beneficial for patients with allergies, characterized by overwhelming MC reactions.

• Klíčová slova
• Allergy, Antiviral immune response, Exosomes, FcεRI, Mast cell degranulation, Mast cells, Tetraspanins,
• MeSH
• degranulace buněk MeSH
• exozómy metabolismus   MeSH
• lidé MeSH
• mastocyty imunologie   metabolismus   MeSH
• myši MeSH
• signální transdukce MeSH
• tetraspaniny genetika   imunologie   metabolismus   MeSH
• virové nemoci imunologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• tetraspaniny MeSH

Background:The intratumoural heterogeneity, often driven by epithelial-to-mesenchymal transition (EMT), significantly contributes to chemoresistance and disease progression in adenocarcinomas. Methods:We introduced a high-throughput screening platform to identify surface antigens that associate with epithelial–mesenchymal plasticity in well-defined pairs of epithelial cell lines and their mesenchymal counterparts. Using multicolour flow cytometry, we then analysed the expression of 10 most robustly changed antigens and identified a 10-molecule surface signature, in pan-cytokeratin-positive/EpCAM-positive and -negative fractions of dissociated breast tumours. Results:We found that surface CD9, CD29, CD49c, and integrin ß5 are lost in breast cancer cells that underwent EMT in vivo. The tetraspanin family member CD9 was concordantly downregulated both in vitro and in vivo and associated with epithelial phenotype and favourable prognosis. Conclusions:We propose that overall landscape of 10-molecule surface signature expression reflects the epithelial–mesenchymal plasticity in breast cancer.

• MeSH
• antigeny CD9 biosyntéza   imunologie   MeSH
• antigeny nádorové biosyntéza   imunologie   MeSH
• antigeny povrchové biosyntéza   imunologie   MeSH
• epitelo-mezenchymální tranzice imunologie   MeSH
• genetická transkripce MeSH
• lidé MeSH
• metastázy nádorů MeSH
• nádorové biomarkery MeSH
• nádorové buněčné linie MeSH
• nádory prsu genetika   imunologie   patologie   MeSH
• plasticita buňky imunologie   MeSH
• přeprogramování buněk fyziologie   MeSH
• průtoková cytometrie MeSH
• rychlé screeningové testy MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny CD9 MeSH
• antigeny nádorové MeSH
• antigeny povrchové MeSH
• CD9 protein, human MeSH Prohlížeč
• nádorové biomarkery MeSH

The acrosome reaction (AR) is a process of membrane fusion and lytic enzyme release, which enables sperm to penetrate the egg surroundings. It is widely recognized that specific sperm proteins form an active network prior to fertilization, and their dynamic relocation is crucial for the sperm-egg fusion. The unique presence of the membrane cofactor protein CD46 in the sperm acrosomal membrane was shown, however, its behaviour and connection with other sperm proteins has not been explored further. Using super resolution microscopy, we demonstrated a dynamic CD46 reorganisation over the sperm head during the AR, and its interaction with transmembrane protein integrins, which was confirmed by proximity ligation assay. Furthermore, we propose their joint involvement in actin network rearrangement. Moreover, CD46 and β1 integrins with subunit α3, but not α6, are localized into the apical acrosome and are expected to be involved in signal transduction pathways directing the acrosome stability and essential protein network rearrangements prior to gamete fusion.

• Publikační typ
• časopisecké články MeSH

The plasma membrane contains diverse and specialized membrane domains, which include tetraspanin-enriched domains (TEMs) and transmembrane adaptor protein (TRAP)-enriched domains. Recent biophysical, microscopic, and functional studies indicated that TEMs and TRAP-enriched domains are involved in compartmentalization of physicochemical events of such important processes as immunoreceptor signal transduction and chemotaxis. Moreover, there is evidence of a cross-talk between TEMs and TRAP-enriched domains. In this review we discuss the presence and function of such domains and their crosstalk using mast cells as a model. The combined data based on analysis of selected mast cell-expressed tetraspanins [cluster of differentiation (CD)9, CD53, CD63, CD81, CD151)] or TRAPs [linker for activation of T cells (LAT), non-T cell activation linker (NTAL), and phosphoprotein associated with glycosphingolipid-enriched membrane microdomains (PAG)] using knockout mice or specific antibodies point to a diversity within these two families and bring evidence of the important roles of these molecules in signaling events. An example of this diversity is physical separation of two TRAPs, LAT and NTAL, which are in many aspects similar but show plasma membrane location in different microdomains in both non-activated and activated cells. Although our understanding of TEMs and TRAP-enriched domains is far from complete, pharmaceutical applications of the knowledge about these domains are under way.

• Klíčová slova
• CD9, IgE receptor, LAT, NTAL, membrane microdomains, plasma membrane, signal transduction,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Chemotaxis, a process leading to movement of cells toward increasing concentrations of chemoattractants, is essential, among others, for recruitment of mast cells within target tissues where they play an important role in innate and adaptive immunity. Chemotaxis is driven by chemoattractants, produced by various cell types, as well as by intrinsic cellular regulators, which are poorly understood. In this study we prepared a new mAb specific for the tetraspanin CD9. Binding of the antibody to bone marrow-derived mast cells triggered activation events that included cell degranulation, Ca(2+) response, dephosphorylation of ezrin/radixin/moesin (ERM) family proteins, and potent tyrosine phosphorylation of the non-T cell activation linker (NTAL) but only weak phosphorylation of the linker for activation of T cells (LAT). Phosphorylation of the NTAL was observed with whole antibody but not with its F(ab)(2) or Fab fragments. This indicated involvement of the Fcγ receptors. As documented by electron microscopy of isolated plasma membrane sheets, CD9 colocalized with the high-affinity IgE receptor (FcεRI) and NTAL but not with LAT. Further tests showed that both anti-CD9 antibody and its F(ab)(2) fragment inhibited mast cell chemotaxis toward antigen. Experiments with bone marrow-derived mast cells deficient in NTAL and/or LAT revealed different roles of these two adaptors in antigen-driven chemotaxis. The combined data indicate that chemotaxis toward antigen is controlled in mast cells by a cross-talk among FcεRI, tetraspanin CD9, transmembrane adaptor proteins NTAL and LAT, and cytoskeleton-regulatory proteins of the ERM family.

• MeSH
• adaptorové proteiny signální transdukční metabolismus   MeSH
• antigeny CD9 fyziologie   MeSH
• antigeny CD98 - lehké řetězce metabolismus   MeSH
• antigeny metabolismus   MeSH
• biologické modely MeSH
• buněčná membrána metabolismus   MeSH
• chemotaxe MeSH
• cytoskelet metabolismus   MeSH
• fosfoproteiny metabolismus   MeSH
• fosforylace MeSH
• glukuronidasa metabolismus   MeSH
• imunoglobuliny - Fab fragmenty chemie   MeSH
• krysa rodu Rattus MeSH
• mastocyty cytologie   MeSH
• membránové proteiny metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• potkani Wistar MeSH
• receptory IgE metabolismus   MeSH
• transportní systém aminokyselin y+ metabolismus   MeSH
• tyrosin chemie   MeSH
• vápník metabolismus   MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• antigeny CD9 MeSH
• antigeny CD98 - lehké řetězce MeSH
• antigeny MeSH
• fosfoproteiny MeSH
• glukuronidasa MeSH
• imunoglobuliny - Fab fragmenty MeSH
• Lat protein, mouse MeSH Prohlížeč
• Lat protein, rat MeSH Prohlížeč
• membránové proteiny MeSH
• receptory IgE MeSH
• SLC7A8 protein, mouse MeSH Prohlížeč
• Slc7a8 protein, rat MeSH Prohlížeč
• transportní systém aminokyselin y+ MeSH
• tyrosin MeSH
• vápník MeSH