Differences in the proteomic content of extracellular vesicles of two strains with different pathogenicity of Giardia lamblia

MOYANO, SOFÍA; MUSSO, JULIANA; LALLE, MARCO; TOUZ, MARÍA CAROLINA

Simposio; XXXII Reunión Anual de la Sociedad Argentina de Protozoología; 2020

Extracellular vesicles (EVs) participate in intercellular communication by selectivelytransferring nucleic acids, lipids, and proteins. The EVs have been isolated andcharacterized in different parasites and have special relevance since they are involved inpathogenesis, adaptation to new environments, and in communication. Giardia lamblia is thecausal agent of a disease known as giardiasis, which is more prevalent in developingcountries. Humans can be infected only by parasites belonging to assemblages A (isolateWB) and B (isolate GS), with differences in infectivity and pathogenesis between the two.Considering that the EVs have the ability to release virulence factors, we studied whether adisparity in the content of proteins present between both assemblages could also be a causeof the difference in infectivity and pathogenesis in them. In this work, G. lamblia vesicleswere isolated by differential ultracentrifugations. The vesicles obtained were morphologicallycharacterized by electron microscopy and the proteins analyzed using high-resolution massspectrometry. In both assemblages, vesicles of different sizes were observed and theproteome showed the presence of conserved proteins and specific proteins of the parasite.Furthermore, proteins associated exclusively with exosomes (endosomal origin) and MVs(plasma membrane origin) were identified. Proteins that act as virulence factors and specificassembly proteins were also present. Our results indicate that assemblages A and B of G.lamblia secrete vesicles with microvesicle and exosomes characteristics but also withparticular proteins that could explain the differences in pathogenesis that exist between bothisolates.