Excretory/Secretory Proteome of the Adult Developmental Stage of Human Blood Fluke, Schistosoma japonicum

Abstract

Schistosomes are the causative agents of schistosomiasis, one of the most prevalent and serious of the parasitic diseases that currently infects ϳ200 million people worldwide. Schistosome excretory/secretory (ES) proteins have been shown to play important roles in modulating mammalian host immune systems. In our current study, we performed a global proteomics identification of the ES proteins from adult worms of Schistosoma japonicum, one of the three major schistosome species. Our results unambiguously identified 101 proteins, including 53 putatively secreted proteins. By quantitative analysis, we revealed fatty acid-binding protein as a major constituent of the in vitro ES proteome. Strikingly the heat shock proteins HSP70s, HSP90, and HSP97 constituted the largest protein family in the ES proteome, implying a central role for these proteins in immunomodulation in the hostparasite relationship. Other important S. japonicum ES proteins included actins, 14-3-3, aminopeptidase, enolase, and glyceraldehyde-3-phosphate dehydrogenase, some of which have been considered as viable vaccine candidates and therapeutic targets. A comparison with previous studies suggests that 48.5% of S. japonicum ES proteins are common to other parasite ES products, indicating that the molecular mechanisms involved in evading the host immune response may be conserved across different parasites. Interestingly seven host proteins, including antimicrobial protein CAP18, immunoglobulins, and a complement component, were identified among in vitro S. japonicum ES products likely originating from the schistosome tegument or gut, indicating that host innate and acquired immune systems could defend against schistosome invasion. Our present study represents the first attempt at profiling S. japonicum ES proteins, provides an insight into host-parasite interactions, and establishes a resource for the devel-

Whole-genome sequence of Schistosoma haematobium

“…5-7). The number of S. haematobium genes was consistent with those of S. mansoni (13,184) and S. japonicum (13,469), as were the gene structures. Most (9,714) S. haematobium genes were supported by the RNA-seq data from adult and egg stages.…”

“…In addition, classical excretorysecretory (ES) proteins of S. haematobium were predicted (on the basis of the presence of a signal peptide at the N terminus) using SignalP v.3.0 (ref. 40; using both the neural network and hidden Markov models) and the absence of a transmembrane domain using TMHMM 41 , and by BLASTp 42 homology-searching of the validated signal peptide database (SPD) 43 and an ES database containing published proteomic data for nematodes (Brugia malayi and Meloidogyne incognita) and trematodes (S. mansoni, S. japonicum, O. viverrini and F. hepatica) 13,14,[44][45][46][47][48][49][50] . The secondary structure of genes specific to S. haematobium were predicted using PSIPRED 51 .…”

“…Whole-genome sequence of Schistosoma haematobium l e t t e r s and/or adult (including cathepsin B, heat-shock proteins, thioredoxin peroxidase, superoxide dismutase, protein disulfide isomerase and venom allergen-like proteins) 13,14 . High-stringency genetic networking of the entire genomic data set identified major hubs of connectivity for conserved molecules associated with nucleotide and protein synthesis and degradation and with signal transduction (Supplementary Note, Supplementary Tables 11 and 12, Supplementary Fig.…”

Vaccinomics for the Major Blood Feeding Helminths of Humans

“…The presumption that proteins released in vitro mimic or at least resemble the suite of proteins released in vivo is contentious, and this is particularly evident in the ES proteome of schistosome cercariae, where of 48 spots detected on a 2D-gel, 29 were thought to originate in the secretory vesicles and 18 from the cytosol of the secretion glands, with the latter thought to be due to holocrine secretion (Curwen et al, 2006). This controversy is further highlighted by the fact that only approximately half of the proteins in the ES products from adults of S. japonicum were putatively secreted (based on their gene ontologies) and some of the most abundant proteins detected are of known intracellular origin (Liu et al, 2009).…”

Efficacy of Dot-ELISA using different antigens in detecting anti-schistosome antibodies among bovines in field conditions

“…Excretory-secretory antigens (ESA) of S. spindale were prepared based on the method of Liu et al (2009) with some modifications. Eight hundred adult worms were soaked in 1X phosphate buffered saline (PBS, pH 7.4) for 2 h at room temperature followed by overnight incubation at 4°C.…”