Amaranthus leucocarpus lectin (ALL), specific for N-acetyl-D-galactosamine, induces inhibition of the erythrophagocytic activity of resident murine peritoneal macrophages and of the macrophage-like cell line J-774. This effect was observed only in macrophages that were Mac-2 (CD11c/CD18 or CR4) negative, indicating that macrophage activation induces important modification to the glycosylation (mainly O-glycosylation) of the membrane. Receptors for IgM and C3b remain unaltered after lectin treatment. Ultrastructural analysis revealed (a) that ALL induced the formation of pinocytic vacuoles, and (b) a regular distribution over the macrophage membrane as well as endosomal vesicles of the gold labeled ALL. Our results suggest that macrophage membrane glycoproteins with constitutive N-acetyl-D-galactosamine residues participate in the regulation of pinocytic-phagocytic vacuole formation.
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http://dx.doi.org/10.1023/a:1006972011711 | DOI Listing |
Front Immunol
February 2022
Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
T lymphocyte activation begins with antigen/MHC recognition by the TCR/CD3 complex followed by a costimulatory signal provided by CD28. The search for novel costimulatory molecules has been extensive due to their potential use as immunotherapeutic targets. Although some molecules have been identified, they are unable to provide sustainable signaling to allow for proper T cell activation and proliferation.
View Article and Find Full Text PDFNeuropeptides
February 2018
Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, Mexico. Electronic address:
Amyloid-β (Aβ) plays a relevant role in the neurodegenerative process of Alzheimer's disease (AD). The 25-35 peptide of amyloid-β (Aβ25-35) induces the inflammatory response in brain experimental models. Mucin-type O-glycosylation has been associated with inflammation of brain tissues in AD, thus in this work, we aimed at identifying changes in the glycosylation profile generated by the injection of Aβ25-35 into the CA1 of the hippocampus of rats, using histochemistry with lectins.
View Article and Find Full Text PDFTohoku J Exp Med
September 2016
Unidad de Investigación Médica en Inmunología, Hospital de Pediatría, Centro Médico Nacional "Siglo XXI", Instituto Mexicano del Seguro Social (IMSS).
T cells from patients with systemic lupus erythematosus (SLE) show a decreased activation threshold and increased apoptosis. These processes seem to be regulated by glycosylated molecules on the T cell surface. Here, we determined through flow cytometry the expression of mucin-type O-glycans on T helper cells in peripheral blood mononuclear cells (PBMC) from 23 SLE patients and its relation with disease activity.
View Article and Find Full Text PDFImmun Inflamm Dis
September 2015
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.
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.
View Article and Find Full Text PDFClin Dev Immunol
June 2014
Unidad de Investigación, Instituto de Oftalmología Fundación Conde de Valenciana, 06800 México, DF, Mexico ; Laboratorio de Inmunología, Departamento de Bioquímica, Facultad de Medicina, (UNAM), P.O. Box 70159, 04510 México, DF, Mexico.
O-glycosidically-linked glycans have been involved in development, maturation, homing, and immune regulation in T cells. Previous reports indicate that Amaranthus leucocarpus lectin (ALL), specific for glycans containing galactose-N-acetylgalactosamine and N-acetylgalactosamine, recognizes human naïve CD27(+)CD25(+)CD4(+) T cells. Our aim was to evaluate the phenotype of CD4(+) T cells recognized by ALL in peripheral blood mononuclear cells obtained from healthy volunteers.
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