Conference Paper
CD43 regulates the threshold for T cell activation by targeting Cbl functions
Fecha
2012Autor
Portillo, L.
Olmedilla, A.
Santacruz-Ruvalcaba, F.
Institución
Resumen
In spite of the importance of somatic embryogenesis for basic research in plant embryology as well as for crop improvement and plant propagation, it is still unclear which mechanisms and cell signals are involved in acquiring embryogenic competence by a somatic cell. The aim of this work was to study cellular and molecular changes involved in the induction stage in calli of Agave tequilana Weber cultivar azul in order to gain more information on the initial stages of somatic embryogenesis in this species. Cytochemical and immunocytochemical techniques were used to identify differences between embryogenic and non-embryogenic cells from several genotypes. Presence of granular structures was detected after somatic embryogenesis induction in embryogenic cells; composition of these structures as well as changes in protein and polysaccharide distribution was studied using Coomassie brilliant blue and Periodic Acid-Schiff stains. Distribution of arabinogalactan proteins (AGPs) and pectins was investigated in embryogenic and non-embryogenic cells by immunolabelling using anti-AGP monoclonal antibodies (JIM4, JIM8 and JIM13) as well as an anti-methyl-esterified pectin-antibody (JIM7), in order to evaluate major modifications in cell wall composition in the initial stages of somatic embryogenesis. Our observations pointed out that induction of somatic embryogenesis produced accumulation of proteins and polysaccharides in embryogenic cells. Presence of JIM8, JIM13 and JIM7 epitopes were detected exclusively in embryogenic cells, which supports the idea that specific changes in cell wall are involved in the acquisition of embryogenic competence of A. tequilana. " 2012 Springer-Verlag.",,,,,,"10.1007/s00709-011-0354-6",,,"http://hdl.handle.net/20.500.12104/39936","http://www.scopus.com/inward/record.url?eid=2-s2.0-84867136372&partnerID=40&md5=8697bf02e37182d729b345099769b20e http://ovidsp.ovid.com/ovidweb.cgi?T=JS&CSC=Y&NEWS=N&PAGE=fulltext&D=medl&AN=22270826",,,,,,"4",,"Protoplasma",,"1101 1107",,"249",,"Scopus MEDLINE",,,,"Index Medicus;Agave/em [Embryology];Agave/me [Metabolism];Mucoproteins/me [Metabolism];Pectins/me [Metabolism];Plant Proteins/me [Metabolism];Plant Somatic Embryogenesis Techniques",,"Agave tequilana; Arabinogalactan proteins; Embryogenic cells; Pectins; Somatic embryogenesis",,,,,,"Cellular and molecular changes associated with somatic embryogenesis induction in Agave tequilana",,"Article"
"41707","123456789/35008",,"Pedraza-Alva, G., Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62210, Mexico; Mérida, L.B., Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62210, Mexico, Epithelial Cancer Division, University of Queensland, Diamantina Institute Woolloongabba, Australia; Del Rio, R., Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62210, Mexico, College of Medicine, University of Vermont, Burlington, VT, United States; Fierro, N.A., Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62210, Mexico, Servicio de Biologia Molecular en Medicina, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Jalisco, Mexico; Cruz-Muñoz, M.E., Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62210, Mexico; Olivares, N., Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62210, Mexico, Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, NIAID/NIH, Montana, United States; Melchy, E., Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62210, Mexico; Igras, V., Dana Farber Cancer Institute, Boston, MA, United States; Hollander, G.A., Pediatric Immunology, Department of Research and Clinical-Biological Sciences, United States, Children's Hospital, University of Basel, Basel, Switzerland; Burakoff, S.J., Tish Cancer Institute, Mount Sinai Medical Center, NY, United States; Rosenstein, Y., Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Mor. 62210, Mexico, Dana Farber Cancer Institute, Boston, MA, United States",,"Pedraza-Alva, G. Merida, L.B. Del Rio, R. Fierro, N.A. Cruz-Munoz, M.E. Olivares, N. Melchy, E. Igras, V. Hollander, G.A. Burakoff, S.J. Rosenstein, Y.",,"2011",,"T cell (TC) activation requires the coordinated signaling of the T cell receptor (TCR) and coreceptor molecules, allowing TCs to respond to lower degrees of TCR occupancy. Coreceptor molecules set the threshold for TC activation by controlling different regulatory signaling loops. The Cbl family members prevent undesired activation of T cells by regulating TCR signals. In this report, we show that TC prestimulation by the CD43 coreceptor molecule before TCR engagement inhibits TCR-dependent c-Cbl tyrosine phosphorylation, c-Cbl interaction with the adapter molecule Crk-L and promotes Cbl-b degradation in a PKC?-dependent manner. Consequently, the prolonged tyrosine phosphorylation and delayed degradation of ZAP-70 and of the ζ chain lead to enhanced mitogen-activated protein kinase activation and robust TC response. These data indicates that CD43-mediated signals lower the threshold for TC activation by restricting the c-Cbl and Cbl-b inhibitory effects on TCR signaling. In addition to the strength and duration of intracellular signals, our data underscore temporality with which certain molecules are engaged as yet another mechanism to fine tune TC signal quality, and ultimately immune function. Copyright " 2011 Wiley Periodicals, Inc.