Expression and cellular trafficking of GP82 and GP90 glycoproteins during Trypanosoma cruzi metacyclogenesis

Abstract

BackgroundThe transformation of noninfective epimastigotes into infective metacyclic trypomastigotes (metacyclogenesis) is a fundamental step in the life cycle of Trypanosoma cruzi, comprising several morphological and biochemical changes. GP82 and GP90 are glycoproteins expressed at the surface of metacyclic trypomastigote, with opposite roles in mammalian cell invasion. GP82 is an adhesin that promotes cell invasion, while GP90 acts as a negative regulator of parasite internalization. Our understanding of the synthesis and intracellular trafficking of GP82 and GP90 during metacyclogenesis is still limited. Therefore, we decided to determine whether GP82 and GP90 are expressed only in fully differentiated metacyclic forms or they start to be expressed in intermediate forms undergoing differentiation.MethodsParasite populations enriched in intermediate forms undergoing differentiation were analyzed by quantitative real-time PCR, Western blot, flow cytometry and immunofluorescence to assess GP82 and GP90 expression.ResultsWe found that GP82 and GP90 mRNAs and proteins are expressed in intermediate forms and reach higher levels in fully differentiated metacyclic forms. Surprisingly, GP82 and GP90 presented distinct cellular localizations in intermediate forms compared to metacyclic trypomastigotes. In intermediate forms, GP82 is localized in organelles at the posterior region and colocalizes with cruzipain, while GP90 is localized at the flagellar pocket region.ConclusionsThis study discloses new aspects of protein expression and trafficking during T. cruzi differentiation by showing that the machinery involved in GP82 and GP90 gene expression starts to operate early in the differentiation process and that different secretion pathways are responsible for delivering these glycoproteins toward the cell surface.

The regulation of autophagy differentially affects Trypanosoma cruzi metacyclogenesis

“…Many virulence factors expressed in the infective forms may be modified by this increased hydrolytic activity. The trans-sialidase family member gp82 that is expressed earlier during differentiation is located in cruzipain-positive organelles at the posterior region before it is delivered towards the cell surface [ 42 ]. Autophagic degradation may also contribute to the cytostome-cytopharynx disappearance and the loss of the endocytic ability observed at the end of metacyclogenesis [ 43 ].…”

Oral Versus Intragastric Inoculation: Similar Pathways of Trypanosoma cruzi Experimental Infection? From Target Tissues, Parasite Evasion, and Immune Response

“…By contrast, T. cruzi strains expressing pepsin-susceptible gp90 produced high parasitemia and high mortality when given to mice by the intrapharyngeal route ( 43 ). In addition, analysis of extracellular vesicles and soluble proteins released by metacyclic trypomastigotes forms of T. cruzi has revealed presence of gp82 and gp90 surface molecules in these compartments ( 48 , 49 ).…”

Colchicine treatment reversibly blocks cytokinesis but not mitosis in Trypanosoma cruzi epimastigotes

“…Parasites return to the bloodstream and are free to infect new cells or be ingested by uninfected insects, completing their life cycle . This adaptation to different hosts, alternating between replicative and non-replicative stages, means that the parasite cell cycle must be precisely controlled and closely connected to the metabolic signals present in each environment (Goldenberg and Avila 2011;Bayer-Santos et al 2013).…”