H-IPSE is a pathogen-secreted host nucleus infiltrating protein (infiltrin) expressed exclusively by the Schistosoma haematobium egg stage

Urogenital schistosomiasis, caused by the parasitic trematode Schistosoma haematobium, affects over 112 million people worldwide. As with S. mansoni infections, the pathology in urogenital schistosomiasis is mainly related to the egg stage, which induces granulomatous inflammation of affected tissues. Schistosoma eggs and their secretions have been studied extensively for the related S. mansoni organism which is more amenable to laboratory studies. Indeed, we have shown that IPSE/alpha-1 (M-IPSE herein), a major protein secreted from S .mansoni eggs, can infiltrate host cells. Although M-IPSE function is unknown, its ability to translocate to their nucleus and bind DNA suggests a possible role in immune modulation of host cell tissues. Whether IPSE homologs are expressed in other Schistosome species has not been investigated. Here, we describe the cloning of two paralog genes H03-IPSE and H06-IPSE which are the ortholog of M-IPSE, from the egg-cDNA of S. haematobium. Using PCR and immunodetection, we confirmed that expression of these genes is restricted to the egg stage and female adult worms, while H-IPSE protein is only detectable in mature eggs but not adults. We show that both H03-IPSE and H06-IPSE proteins can infiltrate HTB-9 bladder cells when added exogenously to culture medium. Monopartite C-terminal NLS motifs conserved in H03-IPSE ‘SKRRRKY’ and H06-IPSE ‘SKRGRKY’ NLS motifs, are responsible for targeting the proteins to the nucleus of HTB-9 cells, as demonstrated by site directed mutagenesis and GFP tagging. Thus, S. haematobium eggs express IPSE homologs that appear to perform similar functions in infiltrating host cells

Characterization of the Phytochelatin Synthase of Schistosoma mansoni

Treatment for schistosomiasis, which is responsible for more than 280,000 deaths annually, depends exclusively on the use of praziquantel. Millions of people are treated annually with praziquantel and drug resistant parasites are likely to evolve. In order to identify novel drug targets the Schistosoma mansoni sequence databases were queried for proteins involved in glutathione metabolism. One potential target identified was phytochelatin synthase (PCS). Phytochelatins are oligopeptides synthesized enzymatically from glutathione by PCS that sequester toxic heavy metals in many organisms. However, humans do not have a PCS gene and do not synthesize phytochelatins. In this study we have characterized the PCS of S. mansoni (SmPCS). The conserved catalytic triad of cysteine-histidine-aspartate found in PCS proteins and cysteine proteases is also found in SmPCS, as are several cysteine residues thought to be involved in heavy metal binding and enzyme activation. The SmPCS open reading frame is considerably extended at both the N- and C-termini compared to PCS from other organisms. Multiple PCS transcripts are produced from the single encoded gene by alternative splicing, resulting in both mitochondrial and cytoplasmic protein variants. Expression of SmPCS in yeast increased cadmium tolerance from less than 50 µM to more than 1,000 µM. We confirmed the function of SmPCS by identifying PCs in yeast cell extracts using HPLC-mass spectrometry. SmPCS was found to be expressed in all mammalian stages of worm development investigated. Increases in SmPCS expression were seen in ex vivo worms cultured in the presence of iron, copper, cadmium, or zinc. Collectively, these results indicate that SmPCS plays an important role in schistosome response to heavy metals and that PCS is a potential drug target for schistosomiasis treatment. This is the first characterization of a PCS from a parasitic organism

Highly stabilized low-spin iron(III) and cobalt(III) complexes of a tridentate bis-amide ligand 2,6-bis(N-phenylcarbamoyl)pyridine. Novel nonmacrocyclic tetraamido-N coordination and two unusually short metal-pyridine bonds

This article does not have an abstract

Photodynamic Sensitization of Leishmania amazonensis in both Extracellular and Intracellular Stages with Aluminum Phthalocyanine Chloride for Photolysis In Vitro

Leishmania amazonensis, a causative agent of cutaneous leishmaniasis, is susceptible in vitro to light-mediated cytolysis in the presence of or after pretreatment with the photosensitizer aluminum phthalocyanine chloride. Cytolysis of both promastigotes and axenic amastigotes required less photosensitizer (e.g., one μg · ml(−1)) and a lower light dose (e.g., 1.5 J · cm(−2)) than did the mammalian cells examined for comparison. Exposure of Leishmania cells to the photosensitizer alone had little effect on their viability, as judged from their motility, growth, and/or retention of green fluorescent proteins genetically engineered for episomal expression. Fluorimetric assays for cell-associated and released green fluorescence proteins proved to be even more sensitive for the evaluation of cell viability than microscopy for the evaluation of motility and/or integrity. Axenic amastigotes pretreated with the photosensitizer infected macrophages of the J774 line but were lysed intracellularly when the infected cells were exposed to light. Addition of the photosensitizer to the already infected cells produced no effect on their intracellular parasites. However, light irradiation lysed these macrophages and also those infected with parasites preincubated with the photosensitizer at a concentration of 5 μg · ml(−1) or higher. Photosensitized Leishmania cells are highly susceptible to cytolysis, apparently due to the generation of reactive oxidative species on light illumination, suggestive of inefficiency of their antioxidant mechanisms. Efficient delivery of photosensitizers to intracellular Leishmania is expected to increase their therapeutic potentials against leishmaniasis

Transcriptional Profiling of the Bladder in Urogenital Schistosomiasis Reveals Pathways of Inflammatory Fibrosis and Urothelial Compromise

Urogenital schistosomiasis, chronic infection by Schistosoma haematobium, affects 112 million people worldwide. S. haematobium worm oviposition in the bladder wall leads to granulomatous inflammation, fibrosis, and egg expulsion into the urine. Despite the global impact of urogenital schistosomiasis, basic understanding of the associated pathologic mechanisms has been incomplete due to the lack of suitable animal models. We leveraged our recently developed mouse model of urogenital schistosomiasis to perform the first-ever profiling of the early molecular events that occur in the bladder in response to the introduction of S. haematobium eggs. Microarray analysis of bladders revealed rapid, differential transcription of large numbers of genes, peaking three weeks post-egg administration. Many differentially transcribed genes were related to the canonical Type 2 anti-schistosomal immune response, as reflected by the development of egg-based bladder granulomata. Numerous collagen and metalloproteinase genes were differentially transcribed over time, revealing complex remodeling and fibrosis of the bladder that was confirmed by Masson\u27s Trichrome staining. Multiple genes implicated in carcinogenesis pathways, including vascular endothelial growth factor-, oncogene-, and mammary tumor-related genes, were differentially transcribed in egg-injected bladders. Surprisingly, junctional adhesion molecule, claudin and uroplakin genes, key components for maintaining the urothelial barrier, were globally suppressed after bladder exposure to eggs. This occurred in the setting of urothelial hyperplasia and egg shedding in urine. Thus, S. haematobium egg expulsion is associated with intricate modulation of the urothelial barrier on the cellular and molecular level. Taken together, our findings have important implications for understanding host-parasite interactions and carcinogenesis in urogenital schistosomiasis, and may provide clues for novel therapeutic strategies. © 2012 Ray et al

Transmembrane Molecules for Phylogenetic Analyses of Pathogenic Protists: Leishmania-Specific Informative Sites in Hydrophilic Loops of Trans- Endoplasmic Reticulum N-Acetylglucosamine-1-Phosphate Transferase

A sequence database was created for the Leishmania N-acetylglucosamine-1-phosphate transferase (nagt) gene from 193 independent isolates. PCR products of this single-copy gene were analyzed for restriction fragment length polymorphism based on seven nagt sequences initially available. We subsequently sequenced 77 samples and found 19 new variants (genotypes). Alignment of all 26 nagt sequences is gap free, except for a single codon addition or deletion. Phylogenetic analyses of the sequences allow grouping the isolates into three subgenera, each consisting of recognized species complexes, i.e., subgenus Leishmania (L. amazonensis-L. mexicana, L. donovani-L. infantum, L. tropica, L. major, and L. turanica-L. gerbilli), subgenus Viannia (L. braziliensis, L. panamensis), and one unclassified (L. enriettii) species. This hierarchy of grouping is also supported by sequence analyses of selected samples for additional single-copy genes present on different chromosomes. Intraspecies divergence of nagt varies considerably with different species complexes. Interestingly, species complexes with less subspecies divergence are more widely distributed than those that are more divergent. The relevance of this to Leishmania evolutionary adaptation is discussed. Heterozygosity of subspecies variants contributes to intraspecies diversity, which is prominent in L. tropica but not in L. donovani-L. infantum. This disparity is thought to result from the genetic recombination of the respective species at different times as a rare event during their predominantly clonal evolution. Phylogenetically useful sites of nagt are restricted largely to several extended hydrophilic loops predicted from hypothetical models of Leishmania NAGT as an endoplasmic reticulum transmembrane protein. In silico analyses of nagt from fungi and other protozoa further illustrate the potential value of this and, perhaps, other similar transmembrane molecules for phylogenetic analyses of single-cell eukaryotes

IPSE, a urogenital parasite derived protein, drives urothelial proliferation and alleviates chemotherapy induced hemorrhagic cystitis

Introduction and Objective: Chemotherapy-induced hemorrhagic cystitis can be a difficult-to-manage complication. We previously reported that a single dose of H-IPSEH06, a Schistosoma haematobium-derived host immunomodulatory protein, is superior to three doses of Mesna in preventing ifosfamide-induced hemorrhagic cystitis. Herein, we expand upon this work in three directions: 1) characterization of H-IPSEH06’s influence over urothelial proliferation; 2) elucidating the mechanism of IPSE’s therapeutic effect through transcriptional profiling. Methods: Recombinant H-IPSE or an NLS mutant of IPSE (H-IPSENLS) was incubated with mouse and human urothelial cell lines, and proliferation and cell cycle status measured by flow cytometry using CFSE and propidium iodide, respectively. Cellular RNA were isolated and subjected to RNA-seq analysis. Mice were administered H-IPSEH06 or H-IPSENLS, challenged with ifosfamide, and their bladder RNA subjected to RNA-seq analysis. Results: H-IPSEH06 increased both mouse and human urothelial cell proliferation, and drove cells towards S-phase. These effects are NLS dependent, and are consistent with H-IPSEH06’s ability to protect the urothelium following ifosfamide challenge. RNA-seq analysis revealed that several cell proliferation related pathways were differentially expressed between H-IPSEH06 vs vehicle-treated mice challenged with ifosfamide. Also, multiple muscle contraction-related pathways are differentially expressed between H-IPSEH06 vs H-IPSENLS-treated mice challenged with ifosfamide. These findings are consistent with H-IPSEH06’s ability to prevent ifosfamide induced bladder dysfunction. Conclusion: H-IPSEH06 continues to prove to be a promising prophylactic against chemotherapy-induced hemorrhagic cystitis. Our mechanistic studies on H-IPSEH06 suggest potential means by which to optimize this molecule’s NLS-dependent therapeutic effects

Evaluation of the CCA Immuno-Chromatographic Test to Diagnose Schistosoma mansoni in Minas Gerais State, Brazil.

BACKGROUND: The Kato-Katz (KK) stool smear is the standard test for the diagnosis of Schistosoma mansoni infection, but suffers from low sensitivity when infections intensities are moderate to low. Thus, misdiagnosed individuals remain untreated and contribute to the disease transmission, thereby forestalling public health efforts to move from a modality of disease control to one of elimination. As an alternative, the urine-based diagnosis of schistosomiasis mansoni via the circulating cathodic antigen immuno-chromatographic test (CCA-ICT) has been extensively evaluated in Africa with the conclusion that it may replace the KK test in areas where prevalences are moderate or high. METHODS AND FINDINGS: The objective was to measure the performance of the CCA-ICT in a sample study population composed of residents from non-endemic and endemic areas for schistosomiasis mansoni in two municipalities of Minas Gerais state, Brazil. Volunteers (130) were classified into three infection status groups based on duplicate Kato-Katz thick smears from one stool sample (2KK test): 41 negative individuals from non-endemic areas, 41 negative individuals from endemic areas and 48 infected individuals from endemic areas. Infection status was also determined by the CCA-ICT and infection exposure by antibody ELISA (enzyme-linked immunosorbent assay) to S. mansoni soluble egg antigen (SEA) and soluble (adult) worm antigen preparation (SWAP). Sensitivity and specificity were influenced by whether the trace score visually adjudicated in the CCA-ICT was characterized as positive or negative for S. mansoni infection. An analysis of a two-graph receiver operating characteristic was performed to change the cutoff point. When the trace score was interpreted as a positive rather than as a negative result, the specificity decreased from 97.6% to 78.0% whereas sensitivity increased from 68.7% to 85.4%. A significantly positive correlation between the CCA-ICT scores and egg counts was identified (r = 0.6252, p = 0.0001). However, the CCA-ICT misdiagnosed as negative 14.6% of 2KK positive individuals, predominantly those with light infections (fewer than 100 eggs/g feces). Considering 2KK as reference test, the discriminating power of the CCA-ICT (the area under the curve [AUC] = 0.817) was greater than the SEA-ELISA (AUC = 0.744) and SWAP-ELISA (AUC = 0.704). CONCLUSION: Our data for the performance of the CCA-ICT in the Brazilian communities endemic for schistosomiasis mansoni support those from Africa, i.e., in areas with greater infection prevalence and intensities, the CCA-ICT may be useful as a tool to indicate community-based preventative chemotherapy without individual diagnosis. However, because of the Brazilian Ministry of Health\u27s recommendation for individual diagnosis in areas where prevalence is less than 15%, i.e., those areas in which infection intensities are likely to be lowest, the CCA-ICT lacks the sensitivity to be used as standalone diagnostic tool