Schistosoma mansoni Stomatin Like Protein-2 Is Located in the Tegument and Induces Partial Protection against Challenge Infection

Schistosomiasis is a parasitic disease causing serious chronic morbidity in tropical countries. Together with the publication of the transcriptome database, a series of new vaccine candidates were proposed based on their functional classification. However, the prediction of vaccine candidates from sequence information or even by proteomics or microarrays data is somewhat speculative and there remains the considerable task of functional analysis of each new gene/protein. In this study, we present the characterization of one of these molecules, a stomatin like protein 2 (SmStoLP-2). Sequence analysis predicts signals that could contribute to protein membrane association and mitochondrial targeting, which was confirmed by differential extractions of schistosome tegument membranes and mitochondria. Additionally, confocal microscope analysis showed SmStoLP-2 present in the tegument of 7-day-old schistosomula and adult worms. Studies in patients living in endemic areas for schistosomiasis revealed high levels of IgG1, IgG2, IgG3 and IgA anti-SmStoLP-2 antibodies in individuals resistant to reinfection. Recombinant SmStoLP-2 protein, when used as vaccine, induced significant levels of protection in mice. This reduction in worm burden was associated with a typical Th1-type immune response. These results indicate that SmStoLP-2 could be useful in association with other antigens for the composition of a vaccine against schistosomiasis

Antischistosomal activity from Brazilian marine algae

Abstract Schistosomiasis may be caused by six different species of the genus Schistosoma. Current treatment is based only on two drugs: oxamniquine, which is only effective against the Schistosoma mansoni species, and praziquantel, which is ineffective against young parasites. Therefore, research on new drugs and their targets for the treatment of this disease is urgently needed. In the present work, the efficacies of several seaweeds extracts against S. mansoni were tested. Worm couples were incubated with different concentration of seaweed extracts for 120 h and monitored after the first 2 h and then every 24 h to evaluate death, mobility reduction and couple detachment. The extracts of 13 different seaweed species were tested in a first trial and the active extracts were further evaluated in lower concentrations. The extracts of Gracilaria ornata and species belonging to the genera Dictyota and Laurencia showed activity at relatively low concentrations. The active extracts were analyzed by LC–MS, and possible candidates are proposed