CEFYBO   02669
CENTRO DE ESTUDIOS FARMACOLOGICOS Y BOTANICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Characterization of exosomes derived from a murine T-cell lymphoma
Autor/es:
HERSCHLIK LETICIA; DI SCIULLO PAULA; VENDRELL ALEJANDRINA; WALDNER CLAUDIA; MONGINI CLAUDIA
Reunión:
Congreso; Primer Congreso Franco Argentino de Inmunología (FAIC 2010); 2010
Institución organizadora:
Sociedad Argentina de Inmunología, El Grupo rioplatense de citometría de flujo y Grupo de inmunología pediátrica de la SAP
Resumen:
Exosomes are 60 to 100 nm lipid bilayer vesicles comprising an enclosed compartment topologically equivalent to the cytoplasm, and with the extracellular domains of transmembrane proteins at their surface. Exosomes originate in the late endosomal compartment by inward budding of the limiting endosomal membrane, thereby generating intracellular multivesicular bodies (MVBs) released in the extracellular medium upon constitutive or induced fusion of MVBs and plasma membranes. LBC cell line is a murine T-cell lymphoma expressing MHC I, CD8, CD24, CD16 and TCRƒÒ. The aim of this work was to characterize exosomes derived from the T-cell lymphoma LBC to be used as a cell free immunogen. Supernatants of LBC cells cultured until a density of 1,50 to 2,00 E+06/ml were collected and sequentially centrifuged at 300g, 2,000g then at 10,000g and finally exosomes were then pelleted at 100,000g and washed once in PBS. Traditional cultures of LBC cells gave an average yield of (0.37¡Ó0.07)£gg of protein (measured by Lowry assay) per 1,00 E+06 LBC cells. Exosome preparations, analyzed by electron microscopy, displayed the characteristic exosomal morphology. Beads coated with exosomes were stained with conjugated monoclonal antibodies, and analyzed by flow cytometry. We found exosomes were abundant in the following proteins: MHC Class I, the heat stable protein CD24, the heat shock protein Hsp90 and CD8. It was not possible to detect Hsp60 and Hsp70, even though these proteins are present intracytoplasmatically in LBC cells. Our results demonstrated the presence of proteins with immunological relevance on exosomes derived from LBC cells. Expression of MHC I, the heat stable antigen CD24 or the heat shock protein Hsp90, molecules involved in antigen presentation and ligand-receptor interactions can lead to the activation or modulation of various immune responses and therefore might be useful in developing cancer immunotherapies.