RESUMO
Schistosoma mansoni venom allergen-like proteins (SmVALs) are part of a diverse protein superfamily partitioned into two groups (group 1 and group 2). Phylogenetic analyses of group 1 SmVALs revealed that members could be segregated into subclades (A-D); these subclades share similar gene expression patterns across the parasite lifecycle and immunological cross-reactivity. Furthermore, whole-mount in situ hybridization demonstrated that the phylogenetically, transcriptionally and immunologically-related SmVAL4, 10, 18 and 19 (subclade C) were all localized to the pre-acetabular glands of immature cercariae. Our results suggest that SmVAL group 1 phylogenetic relationships, stage-specific transcriptional profiles and tissue localization are predictive of immunological cross-reactivity.
Assuntos
Antígenos de Helmintos/imunologia , Proteínas de Helminto/imunologia , Filogenia , Schistosoma mansoni/química , Alérgenos/classificação , Alérgenos/genética , Alérgenos/imunologia , Animais , Antígenos de Helmintos/classificação , Antígenos de Helmintos/genética , Western Blotting , Reações Cruzadas , Vacinas contra Dengue/imunologia , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Perfilação da Expressão Gênica , Proteínas de Helminto/classificação , Proteínas de Helminto/genética , Soros Imunes/imunologia , Espectrometria de Massas , Família Multigênica , Schistosoma mansoni/classificação , Schistosoma mansoni/genética , Schistosoma mansoni/imunologia , Transcrição GênicaRESUMO
The characteristics of parasitic infections are often tied to host behavior. Although most studies have investigated definitive hosts, intermediate hosts can also play a role in shaping the distribution and accumulation of parasites. This is particularly relevant in larval stages, where intermediate host's behavior could potentially interfere in the molecules secreted by the parasite into the next host during infection. To investigate this hypothesis, we used a proteomic approach to analyze excretion/secretion products (ESP) from Fasciola hepatica newly excysted juveniles (NEJ) derived from two intermediate host species, Lymnaea viatrix and Pseudosuccinea columella. The two analyzed proteomes showed differences in identity, abundance, and functional classification of the proteins. This observation could be due to differences in the biological cycle of the parasite in the host, environmental aspects, and/or host-dependent factors. Categories such as protein modification machinery, protease inhibitors, signal transduction, and cysteine-rich proteins showed different abundance between samples. More specifically, differences in abundance of individual proteins such as peptidyl-prolyl cis-trans isomerase, thioredoxin, cathepsin B, cathepsin L, and Kunitz-type inhibitors were identified. Based on the differences identified between NEJ ESP samples, we can conclude that the intermediate host is a factor influencing the proteomic profile of ESP in F. hepatica.
Assuntos
Fasciola hepatica/metabolismo , Proteínas de Helminto/metabolismo , Lymnaea/parasitologia , Proteômica , Caramujos/parasitologia , Animais , Anidrases Carbônicas/classificação , Anidrases Carbônicas/metabolismo , Proteínas de Helminto/classificação , Larva/metabolismo , Peptídeo Hidrolases/classificação , Peptídeo Hidrolases/metabolismo , Peroxirredoxinas/classificação , Peroxirredoxinas/metabolismo , Inibidores de Proteases/classificação , Inibidores de Proteases/metabolismo , Receptores de Superfície Celular/classificação , Receptores de Superfície Celular/metabolismoRESUMO
The insert of a clone from a lambdagt11 Echinococcus granulosus (Platyhelminth, Cestoda) protoscolex cDNA library, showed an open reading frame whose deduced protein sequence presents a high homology with all described thioredoxins (TRX). The TRX active site (Trp-Cys-Gly-Pro-Cys) is completely conserved. With a monospecific antibody, selected from a total anti-protoscolex sera by the isolated clone, a 12 kDa polypeptide was immunoprecipitated from a protoscolex total protein extract. Furthermore, an antiserum raised against a recombinant EgTRX also recognizes a 12 kDa band in these extracts. The recombinant protein presents TRX activity, using the insulin reduction assay. Finally, a TRX activity was characterized in protoscolex extracts. In all organisms where TRXs were studied, they participate in a cascade of redox exchanges, contributing to the maintaining of cell homeostasis. Considering that the parasitic flatworm E. granulosus is probably submitted to an important oxidative stress due to host defences, EgTRX protein could be involved in the survival strategies of this parasite.