Banca de DEFESA: TAISE CRISTINA SANTA BARBARA SILVA QUEIROZ
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : TAISE CRISTINA SANTA BARBARA SILVA QUEIROZ
DATA : 27/10/2020
HORA: 09:00
LOCAL: Webconferência
TÍTULO:
. Characterization of Extracellular Vesicles to macrophages infected with Leishmania braziliensis and its immunomodulatory effects
PALAVRAS-CHAVES:
Extracellular vesicle, Leishmania braziliensis, macrophage, leishmaniasis
PÁGINAS: 53
GRANDE ÁREA: Ciências Biológicas
ÁREA: Parasitologia
RESUMO:
ABSTRACT
Leishmaniasis is a neglected tropical disease with a wide clinical spectrum, caused by protozoa parasites of the genus Leishmania. Several groups report the secretion of extracellular vesicles (EVs) in Leishmania species, such particles have the main function of cellular communication, exerting effects on the parasite-host interaction and between the parasites. In addition, in vitro and in vivo experiments demonstrate the enrichment of EVs with biomolecules, as virulence factors, fundamental in the infectious process. Thus, our objective was to characterize the EVs secreted by murine macrophages infected with L. braziliensis and to evaluate the effect of stimulation of cells with these EVs, in terms of parasitic load and cytokine production. EVs were obtained from macrophage cultures infected with L. braziliensis and isolated by differential centrifugation followed by ultracentrifugation. Scanning electron microscopy images suggests that EV release occurs throughout the cell body of macrophages infected with L. braziliensis. Nanoparticla Tracking Analysis (NTA) showed that EVs obtained from macrophages infected for 24 hours have an average diameter of 155.91 nm. NTA also showed that the amount of EVs produced by infected macrophages was similar (152.35 x 108 VE/ml) to that observe in control macrophages (125.83 x 108 VE/ml), at 24h. Stimulation of cells with 108 EVs/ml, obtained from either control or infected macrophages significantly reduced the parasite load of macrophages upon infection with L. braziliensis. In parallel, stimulation of macrophages with 108 EVs/ml (regardless of the origin of the EV), followed by infection with L. braziliensis reduced the production of TNF when compared to cultures that remained without stimulation. This work provides a new perspective regarding the production of EVs by cells infected with L. braziliensis and opens a new avenue of investigation regarding its immunomodulatory role in cutaneous leishmaniasis.
MEMBROS DA BANCA:
Presidente - 024.952.207-11 - CAMILA INDIANI DE OLIVEIRA - USP
Interno - 796.762.515-34 - JULIANA PERRONE BEZERRA DE MENEZES FULLAM - UFBA
Externo à Instituição - LUCAS PEDREIRA DE CARVALHO - Fiocruz-Ba