title: Amaranthus leucocarpus lectin recognizes a moesin-like O-glycoprotein and costimulates murine CD3-activated CD4(+) T cells.
abstract: The Galβ1,3GalNAcα1,O-Ser/Thr specific lectin from Amaranthus leucocarpus (ALL) binds a ∼70 kDa glycoprotein on murine T cell surface. We show that in the absence of antigen presenting cells, murine CD4(+) T cells activated by an anti-CD3 antibody plus ALL enhanced cell proliferation similar to those cells activated via CD3/CD28 at 48 h of culture. Moreover, ALL induced the production of IL-4, IL-10, TNF-alpha, and TGF-beta in CD3-activated cells. Proteomic assay using two-dimensional electrophoresis and far-Western blotting, ALL recognized two prominent proteins associated to the lipid raft microdomains in CD3/CD28-activated CD4(+) T cells. By mass spectrometry, the peptide fragments from ALL-recognized proteins showed sequences with 33% homology to matricin (gi|347839 NCBInr) and 41% identity to an unnamed protein related to moesin (gi|74186081 NCBInr). Confocal microscopy analysis of CD3/CD28-activated CD4(+) T cells confirmed that staining by ALL colocalized with anti-moesin FERM domain antibody along the plasma membrane and in the intercellular contact sites. Our findings suggest that a moesin-like O-glycoprotein is the ALL-recognized molecule in lipid rats, which induces costimulatory signals on CD4(+) T cells.
authors.affiliation: Departamento de Bioquimica, Facultad de Medicina Universidad Nacional Autónoma de México.
authors.forename: Maria
authors.initials: M
authors.lastname: Arenas-Del Ángel
authors.affiliation: Laboratorio de Inmunologia Molecular, Facultad de Estudios Superiores Zaragoza Universidad Nacional Autónoma de México.
authors.forename: Martha
authors.initials: M
authors.lastname: Legorreta-Herrera
authors.affiliation: Departamento de Bioquimica, Facultad de Medicina Universidad Nacional Autónoma de México.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Mendoza-Hernández
authors.affiliation: Departamento de Bioquimica, Facultad de Medicina Universidad Nacional Autónoma de México ; Unidad de Investigación Instituto de Oftalmologia "Fundación Conde de Valenciana"
authors.forename: Yonathan
authors.initials: Y
authors.lastname: Garfias
authors.affiliation: Departamento de Bioquimica, Facultad de Medicina Universidad Nacional Autónoma de México.
authors.forename: Raul
authors.initials: R
authors.lastname: Chávez
authors.affiliation: Departamento de Bioquimica, Facultad de Medicina Universidad Nacional Autónoma de México.
authors.forename: Edgar
authors.initials: E
authors.lastname: Zenteno
authors.affiliation: Departamento de Bioquimica, Facultad de Medicina Universidad Nacional Autónoma de México ; Departamento de Investigación en Bioquimica Instituto Nacional de Enfermedades Respiratorias "Ismael Cosio Villegas", México.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Lascurain
keywords: Lectin; O-glycosylation; lipid raft; moesin-like protein; oligosaccharide recognition