IQUIBICEN   23947
INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CIENCIAS EXACTAS Y NATURALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
MICROVESICLES PRODUCED BY LACTOBACILLUS CASEI BL23 CONTAINED PROTEINS ASSOCIATED WITH ITS PROBIOTIC ACTIVITY
Autor/es:
PALAVECINO, M; MARTÍNEZ, JH; PÉREZ, OE; DOMÍNGUEZ RUBIO, AP; PIURI, M
Lugar:
Ciudad Autónoma de Buenos Aires
Reunión:
Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017
Institución organizadora:
Sociedades de Biociencias (SAIC, SAIB, SAI, SAA, SAFb, SAFf, SAFES, SAFI, SAH, SAP)
Resumen:
Extracellular vesicles in Gram positive bacteria they are also known as microvesicles (MVs) and they have been proposed to be involved in signaling between probiotic bacteria and their mammalian hosts. The aim of this study is to investigate the isolation and characterization of MVs released from the probiotic strain L. casei BL23 which is a regular resident of the mammalian gastrointestinal (GI) microbiome.L. casei BL23 was grown in MRS medium at 37°C for 48h. Cells were removed from the culture by centrifugation. Supernatant was then concentrated using a 100 kDa filter membrane. The concentrated supernatant was spun at 110000 g for 2h to pellet MVs. MVs have been characterized by Dynamic Light Scattering (DLS), Atomic Force Microscopy (AFM) and Transmission Electronic Microscopy (TEM). The shedding of MVs was investigated using CFSE staining and further visualization by Confocal Laser Scanning Microscopy (CLSM). Total DNA, RNA and protein were isolated from MVs using QuickZol. Proteins were analyzed by HPLC coupled to mass spectrometry. CLSM imaging of L. casei BL23 showed a protrusion on cells consistent with the shedding of MVs to the extracellular medium. MVs size obtained from DLS data were consistent with measurements from AFM and TEM images (30-50 nm). The negative surface charge (-9±2 mV) could make the MVs stable by virtue of electrostatic repulsion. AFM images suggests that MVs might have a shape ranging from spherical to cup shape morphology. In TEM images we observed MVs with bilayered membranes and electron dense luminal contents; consistent with the presence of DNA, RNA and proteins. Proteomic analysis identified 103 proteins in the MVs including p40 and p75 that have been associated with its probiotic activity.MVs could play a key role in signaling between GI bacteria and their mammalian hosts. The expression and encapsulation of proteins into MVs could represent a scientific novelty, with applications in food, nutraceuticals and clinical therapies.