Paragonimus westermani: Identification and characterization of the fasciclin I domain-containing protein

Comparative Analysis of Proteins of Functionally Different Body Parts of the Fish Parasites Triaenophorus nodulosus and Triaenophorus crassus

PURPOSE

Studies of proteins expressed in the morphological structures of the parasite are necessary for elucidating the biological functions of unknown proteins and understanding the molecular basis of parasitism. The research aim was to investigate the spatial distribution of major proteins in scolex, immature and gravid proglottids of Triaenophorus nodulosus and Triaenophorus crassus.

METHODS

Protein extracts of worm body parts were analyzed using two-dimensional difference gel electrophoresis (DIGE) and mass spectrometry.

RESULTS

Comparison of the protein repertoire of the adult worm and the encysted plerocercoid revealed differences between the worm body parts, life stages and parasite species. The content of proteins associated with the cytoskeleton and musculature (actin, myosin regulatory light chain, and tropomyosin 2) decreased with distance from the scolex. Mature proglottids were rich in transforming growth factor-beta-induced protein, propionyl-CoA carboxylase, glutamate dehydrogenase and beta-tubulin. Interspecific variation in T. nodulosus and T. crassus was found in the content of the myosin, paramyosin, the major vault protein and an uncharacterized secreted protein TRINITY_DN24645. Differential expression of TRINITY_DN24645, paramyosin and tropomyosin 2 was found between plerocercoids and adult worms.

CONCLUSION

The present study provides the first characteristics of the spatial distribution of the major proteins of T. crassus and T. nodulosus. Comparison of the protein composition of plerocercoids and adult parasites indicates a significant similarity in the proteomic organization of Triaenophorus sp. in the second intermediate and final hosts. The gradual change in the morphological organization of tapeworms in the longitudinal direction coincided with the expression of some structural and metabolic proteins.

Salmon immunological defence and interplay with the modulatory capabilities of its ectoparasite Lepeophtheirus salmonis

The salmon louse Lepeophtheirus salmonis (Lsal) is an ectoparasitic copepod that exerts immunomodulatory and physiological effects on its host Atlantic salmon. Over 30 years of research on louse biology, control, host responses and the host-parasite relationship has provided a plethora of information on the intricacies of host resistance and parasite adaptation. Atlantic salmon exhibit temporal and spatial impairment of the immune system and wound healing ability during infection. This immunosuppression may render Atlantic salmon less tolerant to stress and other confounders associated with current management strategies. Contrasting susceptibility of salmonid hosts exists, and early pro-inflammatory Th1 type responses are associated with resistance. Rapid cellular responses to larvae appear to tip the balance of the host-parasite relationship in favour of the host, preventing severe immune-physiological impacts of the more invasive adults. Immunological, transcriptomic, genomic and proteomic evidence suggests pathological impacts occur in susceptible hosts through modulation of host immunity and physiology via pharmacologically active molecules. Co-evolutionary and farming selection pressures may have incurred preference of Atlantic salmon as a host for Lsal reflected in their interactome. Here, we review host-parasite interactions at the primary attachment/feeding site, and the complex life stage-dependent molecular mechanisms employed to subvert host physiology and immune responses.

Fasciclin-calcareous corpuscle binary complex mediated protein-protein interactions in Taenia solium metacestode

Background

Neurocysticercosis (NC) caused by Taenia solium metacestode (TsM) is a serious neurological disease of global concern. Diverse bioactive molecules involved in the long-term survival of TsM might contribute to disease progression. Fasciclin (Fas) is an extracellular protein that mediates adhesion, migration and differentiation of cells by interacting with other molecules. We hypothesized that TsMFas might bind to calcareous corpuscle (CC) through its adhesive property and participate in crucial protein-protein interactions, thus contributing to the creation of a symbiotic interactome network.

Methods

Two paralogous TsMFas (TsMFas1 and TsMFas2) were isolated, and their molecular properties were characterized. The co-localization pattern of TsMFas1 and TsMFas2 with CC was determined. CC-TsMFas binary complex was generated by incubating CC with recombinant proteins (rTsMFas1 and 2). In vitro binding assay of CC-rTsMFas1 or CC-rTsMFas2 binary complex with TsM cellular proteins extracted from scolex and neck was conducted. Their binding partners were identified through proteomic analysis. Integrated protein-protein interaction networks were established.

Results

TsMFas1 (6072 bp long) was composed of 15 exons (841 amino acid polypeptide) interrupted by 14 introns. TsMFas2 (5201 bp long) comprised of 11 exons (597 amino acids) and 10 intervening introns. These proteins displayed 22% amino acid sequence identity to each other, but tightly conserved Fas-related domains. Several isoforms of Fas1 and Fas2 proteins might have been expressed through post-translational modifications. They showed adhesion activity with other cells. TsMFas proteins were largely distributed in parenchymal regions of the scolex and bladder wall. These molecules were co-localized with CC, a unique organelle found in platyhelminths. Subsequent proteome analysis of CC-Fas binary complex mediated protein-protein interactions revealed seven protein ligands in the TsM cellular proteins. Their functions were mainly segregated into carbohydrate metabolism (enolase, phosphoenolpyruvate carboxykinase, phosphoglycerate kinase and glyceraldehyde 3-phosphate dehydrogenase) and cytoskeleton/cellular motility (actin, paramyosin and innexin nuc-9). Those proteins had direct (physical) and/or indirect (functional) relationships along with their biochemical properties and biological roles.

Conclusion

Protein repertoires strongly suggest that TsMFas and CC may symbiotically mediate protein-protein interactions during biological processes to maintain efficacious homeostatic functions and ensure the prolonged survival of TsM in the host.

Electronic supplementary material

The online version of this article (10.1186/s13071-017-2359-2) contains supplementary material, which is available to authorized users.

Taenia solium metacestode fasciclin-like protein is reactive with sera of chronic neurocysticercosis

OBJECTIVES

Neurocysticercosis (NC), an infection of the central nervous system with Taenia solium metacestodes (TsM), invokes a formidable neurological disease. A bundle of antigens is applicable for serodiagnosis of active cases, while they demonstrate fairly low reactivity against sera of chronic NC. Identification of sensitive biomarkers for chronic NC is critical for appropriate management of patients.

METHODS

Proteome analysis revealed several isoforms of 65- and 83-kDa TsM fasciclin-like proteins (TsMFas) to be highly reactive with sera of chronic NC. A cDNA encoding one of the 83-kDa TsMFas (TsMFas1) was isolated from a cDNA library. We expressed a recombinant protein (rTsMFas1) and evaluated its diagnostic potential employing sera from chronic NC (n = 80), tissue-invasive cestodiases (n = 169) and trematodiases (n = 80) and those of normal controls (n = 50).

RESULTS

Secretory TsMFas1 was composed of 766 amino acid polypeptide and harboured fasciclin and fasciclin-superfamily domains. The protein was constitutively expressed in metacestode and adult stages, with preferential locality in the scolex. Bacterially expressed rTsMFas1 exhibited 78.8% sensitivity (63/80 cases) and 93% specificity (278/299 samples) in diagnosing chronic NC. Some cross-reactivity was observed with sera of cystic echinococcosis (10/56, 17.8%) and sparganosis (4/50, 8%). Positive and negative predictive values were 75% and 95.5%, respectively.

CONCLUSION

TsM fasciclin-like protein may be useful for differential diagnosis of chronic NC in clinical settings, especially where both NC and other infectious cerebral granulomatoses are prevalent.

Neospora caninum: comparative gene expression profiling of Neospora caninum wild type and a temperature sensitive clone

To understand the genetic basis of virulence, gene expression profiles of a temperature-sensitive clone (NCts-8, relatively avirulent) and its wild type (NC-1) of Neospora caninum were characterized and compared using a high-density microarray with approximately 63,000 distinct oligonucleotides. This microarray consists of 5692 unique N. caninum sequences, including 1980 Tentative Consensus sequences and 3712 singleton ESTs from the TIGR N. caninum Gene Index (NCGI, release 5.0). Each sequence was represented by 11 distinct 60mer oligonucleotides synthesized in situ on the microarray. The results showed that 111 genes were significantly repressed and no up-regulated genes were identified in the NCts-8 clone. The level of 10 randomly selected genes from the repressed genes was confirmed using real-time RT-PCR. Of the 111 repressed genes, 58 were hypothetical protein products and 53 were annotated genes. Over 70% of the repressed genes identified in this study are clustered on five chromosomes (I, VII, VIII, X and XII). These results suggest that the down-regulated genes may be in part responsible for the reduced pathogenesis of NCts-8; further characterization of the regulated genes may aid in understanding of molecular basis of virulence and development of countermeasures against neosporosis.