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PLoS Pathogens May 2024The eggs of the blood fluke Schistosoma mansoni are the main cause of the clinical manifestations of chronic schistosomiasis. After laying, the egg "winners" attach to...
The eggs of the blood fluke Schistosoma mansoni are the main cause of the clinical manifestations of chronic schistosomiasis. After laying, the egg "winners" attach to the endothelium of the mesenteric vein and, after a period of development, induce the growth of a small granuloma, which facilitates their passage to the intestinal lumen. Egg "losers" carried by the bloodstream to non-specific tissues also undergo full development and induce large granuloma formation, but their life ends there. Although these trapped eggs represent a dead end in the parasite life cycle, the vast majority of studies attempting to describe the biology of the S. mansoni eggs have studied these liver-trapped "losers" instead of migrating intestinal "winners". This raises the fundamental question of how these eggs differ. With robust comparative transcriptomic analysis performed on S. mansoni eggs isolated 7 weeks post infection, we show that gene expression is critically dependent on tissue localization, both in the early and late stages of development. While mitochondrial genes and venom allergen-like proteins are significantly upregulated in mature intestinal eggs, well-described egg immunomodulators IPSE/alpha-1 and omega-1, together with micro-exon genes, are predominantly expressed in liver eggs. In addition, several proteases and protease inhibitors previously implicated in egg-host interactions display clear tissue-specific gene expression patterns. These major differences in gene expression could be then reflected in the observed different ability of liver and intestinal soluble egg antigens to elicit host immune responses and in the shorter viability of miracidia hatched from liver eggs. Our comparative analysis provides a new perspective on the biology of parasite's eggs in the context of their development and tissue localization. These findings could contribute to a broader and more accurate understanding of parasite eggs interactions with the host, which have historically been often restricted to liver eggs and sometimes inaccurately generalized.
PubMed: 38814989
DOI: 10.1371/journal.ppat.1012268 -
International Journal For Parasitology.... Aug 2024The municipality of Sumidouro in the state of Rio de Janeiro, southeastern Brazil, is considered an area with low endemicity of . In this municipality, the wild water...
The municipality of Sumidouro in the state of Rio de Janeiro, southeastern Brazil, is considered an area with low endemicity of . In this municipality, the wild water rat is a wild reservoir of . A helminth community survey was carried out on populations in Sumidouro from 1997 to 1999. In the present study, we compared the helminth fauna and the helminth community structure of with a recent survey after a 22-year time interval, considering that the prevalence of infection in humans remained stable and that the area showed the same environmental characteristics. Seventy-three host specimens of collected between 1997 and 1999 and 21 specimens collected in 2021 were analyzed in this study. Seven helminth species were found in each collection period. The nematode was recorded for the first time in in 2021. was the most abundant species in both periods and the most prevalent in 2021. During the period from 1997 to 1999, the most prevalent species was . Significant differences in prevalence and abundance in relation to host sex were observed only for in 1997-1999. Significant differences in the abundance of the helminth species over time were observed only in , and were the dominant species in both periods. and became dominant, codominant and subordinate, respectively, over time. In conclusion, the helminth community of remained stable, with similar species richness, prevalence and abundance values and low beta-diversity over time. The occurrence of in the water rat has remained stable for decades, highlighting its importance for schistosomiasis control.
PubMed: 38807751
DOI: 10.1016/j.ijppaw.2024.100941 -
Pharmaceutics May 2024Silybin (SIB) is a hepatoprotective drug known for its poor oral bioavailability, attributed to its classification as a class IV drug with significant metabolism during...
Silybin (SIB) is a hepatoprotective drug known for its poor oral bioavailability, attributed to its classification as a class IV drug with significant metabolism during the first-pass effect. This study explored the potential of solid lipid nanoparticles with (SLN-SIB-U) or without (SLN-SIB) ursodeoxycholic acid and polymeric nanoparticles (PN-SIB) as delivery systems for SIB. The efficacy of these nanosystems was assessed through in vitro studies using the GRX and Caco-2 cell lines for permeability and proliferation assays, respectively, as well as in vivo experiments employing a murine model of infection in BALB/c mice. The mean diameter and encapsulation efficiency of the nanosystems were as follows: SLN-SIB (252.8 ± 4.4 nm, 90.28 ± 2.2%), SLN-SIB-U (252.9 ± 14.4 nm, 77.05 ± 2.8%), and PN-SIB (241.8 ± 4.1 nm, 98.0 ± 0.2%). In the proliferation assay with the GRX cell line, SLN-SIB and SLN-SIB-U exhibited inhibitory effects of 43.09 ± 5.74% and 38.78 ± 3.78%, respectively, compared to PN-SIB, which showed no inhibitory effect. Moreover, SLN-SIB-U demonstrated a greater apparent permeability coefficient (25.82 ± 2.2) than PN-SIB (20.76 ± 0.1), which was twice as high as that of SLN-SIB (11.32 ± 4.6) and pure SIB (11.28 ± 0.2). These findings suggest that solid lipid nanosystems hold promise for further in vivo investigations. In the murine model of acute-phase infection, both SLN-SIB and SLN-SIB-U displayed hepatoprotective effects, as evidenced by lower alanine amino transferase values (22.89 ± 1.6 and 23.93 ± 2.4 U/L, respectively) than those in control groups I (29.55 ± 0.7 U/L) and I+SIB (34.29 ± 0.3 U/L). Among the prepared nanosystems, SLN-SIB-U emerges as a promising candidate for enhancing the pharmacokinetic properties of SIB.
PubMed: 38794280
DOI: 10.3390/pharmaceutics16050618 -
Frontiers in Immunology 2024Schistosomiasis is a common cause of pulmonary hypertension (PH) worldwide. Type 2 inflammation contributes to the development of Schistosoma-induced PH. Specifically,...
BACKGROUND
Schistosomiasis is a common cause of pulmonary hypertension (PH) worldwide. Type 2 inflammation contributes to the development of Schistosoma-induced PH. Specifically, interstitial macrophages (IMs) derived from monocytes play a pivotal role by producing thrombospondin-1 (TSP-1), which in turn activates TGF-β, thereby driving the pathology of PH. Resident and recruited IM subpopulations have recently been identified. We hypothesized that in Schistosoma-PH, one IM subpopulation expresses monocyte recruitment factors, whereas recruited monocytes become a separate IM subpopulation that expresses TSP-1.
METHODS
Mice were intraperitoneally sensitized and then intravenously challenged with S. mansoni eggs. Flow cytometry on lungs and blood was performed on wildtype and reporter mice to identify IM subpopulations and protein expression. Single-cell RNA sequencing (scRNAseq) was performed on flow-sorted IMs from unexposed and at day 1, 3 and 7 following Schistosoma exposure to complement flow cytometry based IM characterization and identify gene expression.
RESULTS
Flow cytometry and scRNAseq both identified 3 IM subpopulations, characterized by CCR2, MHCII, and FOLR2 expression. Following exposure, the CCR2 IM subpopulation expanded, suggestive of circulating monocyte recruitment. exposure caused increased monocyte-recruitment ligand CCL2 expression in the resident FOLR2 IM subpopulation. In contrast, the vascular pathology-driving protein TSP-1 was greatest in the CCR2 IM subpopulation.
CONCLUSION
-induced PH involves crosstalk between IM subpopulations, with increased expression of monocyte recruitment ligands by resident FOLR2 IMs, and the recruitment of CCR2 IMs which express TSP-1 that activates TGF-β and causes PH.
Topics: Animals; Hypertension, Pulmonary; Mice; Macrophages; Phenotype; Schistosoma mansoni; Mice, Inbred C57BL; Schistosomiasis; Disease Models, Animal; Schistosomiasis mansoni; Thrombospondin 1; Monocytes; Receptors, CCR2; Female; Schistosoma; Lung
PubMed: 38779688
DOI: 10.3389/fimmu.2024.1372957 -
Scientific Reports May 2024Metabolism of praziquantel (PZQ), a racemic mixture and the only drug approved to treat S. mansoni infection, is mediated by genetically polymorphic enzymes. Periodic...
Metabolism of praziquantel (PZQ), a racemic mixture and the only drug approved to treat S. mansoni infection, is mediated by genetically polymorphic enzymes. Periodic school-based mass drug administration (MDA) with PZQ is the core intervention to control schistosomiasis. However data on the impact of pharmacogenetic variation, nutrition, and infection status on plasma PZQ exposure is scarce. We investigated genetic and non-genetic factors influencing PZQ plasma concentration and its metabolic ratios (trans-4-OH-PZQ/PZQ and cis-4-OH-PZQ/PZQ). Four hundred forty-six school children aged 7-15 years from four primary schools in southern Ethiopia who received albendazole and PZQ preventive chemotherapy through MDA campaign were enrolled. Genotyping for common functional variants of CYP3A4 (*1B), CYP3A5 (*3, *6), CYP2C19 (*2, *3, *17), CYP2C9 (*2, *3), and CYP2J2*7 was performed. Plasma concentrations of PZQ, trans-4-OH-PZQ, and cis-4-OH-PZQ were quantified using UPLCMS/MS. Carriers of CYP2C19 defective variant alleles (*2 and *3) had significantly higher mean PZQ plasma concentration than CYP2C19*1/*1 or *17 carriers (p = 0.005). CYP2C19*1/*1 and CYP2C19*17 carriers had higher trans-4-OH-PZQ/PZQ and cis-4-OH-PZQ/PZQ metabolic ratios compared with CYP2C19*2 or *3 carriers (p < 0.001). CYP2J2*7 carriers had lower mean PZQ plasma concentration (p = 0.05) and higher trans-4-OH-PZQ/PZQ and cis-4-OH-PZQ/PZQ metabolic ratios. Male participants had significantly higher PZQ concentration (p = 0.006) and lower metabolic ratios (p = 0.001) than females. There was no significant effect of stunting, wasting, S. mansoni or soil-transmitted helminth infections, CYP3A4, CYP3A5, or CYP2C9 genotypes on plasma PZQ or its metabolic ratios. In conclusion, sex, CYP2C19 and CYP2J2 genotypes significantly predict PZQ plasma exposure among Ethiopian children. The impact of CYP2C19 and CYP2J2 genotypes on praziquantel treatment outcomes requires further investigation.
Topics: Humans; Praziquantel; Child; Male; Female; Ethiopia; Adolescent; Cytochrome P-450 CYP2C19; Genotype; Cytochrome P-450 Enzyme System; Anthelmintics; Schistosomiasis mansoni
PubMed: 38778126
DOI: 10.1038/s41598-024-62669-w -
Parasites & Vectors May 2024Snail-borne trematodes afflict humans, livestock, and wildlife. Recognizing their zoonotic potential and possible hybridization, a One Health approach is essential for...
BACKGROUND
Snail-borne trematodes afflict humans, livestock, and wildlife. Recognizing their zoonotic potential and possible hybridization, a One Health approach is essential for effective control. Given the dearth of knowledge on African trematodes, this study aimed to map snail and trematode diversity, focusing on (i) characterizing gastropod snail species and their trematode parasites, (ii) determining infection rates of snail species as intermediate hosts for medically, veterinary, and ecologically significant trematodes, and (iii) comparing their diversity across endemic regions.
METHODS
A cross-sectional study conducted in 2021 in Chiredzi and Wedza districts in Zimbabwe, known for high human schistosomiasis prevalence, involved malacological surveys at 56 sites. Trematode infections in snails were detected through shedding experiments and multiplex rapid diagnostic polymerase chain reactions (RD-PCRs). Morphological and molecular analyses were employed to identify snail and trematode species.
RESULTS
Among 3209 collected snail specimens, 11 species were identified, including schistosome and fasciolid competent snail species. We report for the first time the invasive exotic snail Tarebia granifera in Zimbabwe, which was highly abundant, mainly in Chiredzi, occurring at 29 out of 35 sites. Shedding experiments on 1303 snails revealed a 2.24% infection rate, with 15 trematode species identified through molecular genotyping. Five species were exclusive to Chiredzi: Bolbophorus sp., Schistosoma mansoni, Schistosoma mattheei, Calicophoron sp., and Uvulifer sp. Eight were exclusive to Wedza, including Trichobilharzia sp., Stephanoprora amurensis, Spirorchid sp., and Echinostoma sp. as well as an unidentified species of the Plagiorchioidea superfamily. One species, Tylodelphys mashonensis, was common to both regions. The RD-PCR screening of 976 non-shedding snails indicated a 35.7% trematode infection rate, including the presence of schistosomes (1.1%) Fasciola nyanzae (0.6%). In Chiredzi, Radix natalensis had the highest trematode infection prevalence (33.3%), while in Wedza, R. natalensis (55.4%) and Bulinus tropicus (53.2%) had the highest infection prevalence.
CONCLUSIONS
Our xenomonitoring approach unveiled 15 trematode species, including nine new records in Zimbabwe. Schistosoma mansoni persists in the study region despite six mass deworming rounds. The high snail and parasite diversity, including the presence of exotic snail species that can impact endemic species and biomedically important trematodes, underscores the need for increased monitoring.
Topics: Animals; Zimbabwe; Snails; Trematoda; Cross-Sectional Studies; Introduced Species; Fresh Water; One Health; Humans; Trematode Infections; Biodiversity; Prevalence; Schistosomiasis
PubMed: 38773521
DOI: 10.1186/s13071-024-06307-4 -
Trends in Parasitology May 2024Liebold et al. recently revealed how the identity of dying cells drives distinct changes to the macrophages which engulf and clear them, a process known as...
Liebold et al. recently revealed how the identity of dying cells drives distinct changes to the macrophages which engulf and clear them, a process known as efferocytosis. During infection with the helminth Schistosoma mansoni, liver macrophages recapitulate these phenotypes, mediated by Axl/MerTK receptors and regulating egg burdens.
PubMed: 38772757
DOI: 10.1016/j.pt.2024.05.004 -
Anais Da Academia Brasileira de Ciencias 2024Urban parks are not only important for the wellbeing of the human population, but are also widely considered to be potentially important sites for the conservation of...
Urban parks are not only important for the wellbeing of the human population, but are also widely considered to be potentially important sites for the conservation of biodiversity. However, they may offer risk parasitic infections, such as schistosomiasis and fascioliasis, which are both transmitted by freshwater snails. The present study investigated the occurrence of freshwater gastropods in urban parks of the Brazilian city of Rio de Janeiro, and their possible infection by helminths of medical-veterinary importance. Gastropods were collected from six parks (2021 - 2022) and examined for the presence of larval helminths. In all, 12 gastropod species from different families were collected: Ampullariidae, Assimineidae, Burnupidae, Lymnaeidae, Physidae, Planorbidae, Succineidae, and Thiaridae. The parasitological examination revealed cercaria of three types in five snail species, with the Pleurolophocerca cercariae type in Melanoides tuberculata (the most abundant species), Echinostoma cercariae in Physella acuta and Pomacea maculata, and Virgulate cercariae, in Pomacea sp. and Pomacea maculata. None of the Biomphalaria tenagophila and Pseudosuccinea columella (the most frequent species) specimens were parasitized by Schistosoma mansoni or Fasciola hepatica, respectively. Even so, some parks may represent a considerable potential risk for transmission of both Schistosoma mansoni and Fasciola hepatica, given the presence of these gastropod vectors and the frequent contact of visitors with the waterbodies.
Topics: Animals; Brazil; Fresh Water; Gastropoda; Parks, Recreational; Humans; Snails
PubMed: 38747790
DOI: 10.1590/0001-3765202420230707 -
Tropical Medicine and Health May 2024Community and individual participation are crucial for the success of schistosomiasis control. The World Health Organization (WHO) has highlighted the importance of...
BACKGROUND
Community and individual participation are crucial for the success of schistosomiasis control. The World Health Organization (WHO) has highlighted the importance of enhanced sanitation, health education, and Mass Drug Administration (MDA) in the fight against schistosomiasis. These approaches rely on the knowledge and practices of the community to be successful; however, where the community knowledge is low and inappropriate, it hinders intervention efforts. Hence, it is essential to identify barriers and misconceptions related to awareness of schistosomiasis, sources of infection, mode of transmission, symptoms, and control measures.
METHODS
This was a mixed-method cross-sectional study involving 1200 pre-school children randomly selected and examined for Schistosoma mansoni infection using the Kato-Katz technique. All parents/guardians of selected children were enrolled for a pre-tested questionnaire survey, while 42 were engaged in focus group discussions (FGDs). The level of knowledge and awareness among parents/guardians about schistosomiasis was evaluated in relation to the infection status of their pre-school children.
RESULTS
Among pre-school children, the prevalence of intestinal schistosomiasis was 45.1% (95% CI 41.7-48.5). A majority of parents/guardians (85.5%) had heard about schistosomiasis, and this awareness was associated with the participant's level of education (OR = 0.16, 95% CI 0.08, 0.34). In addition, a positive association was observed between higher educational attainment and knowledge of the causative agent (OR = 0.69, 95% CI 0.49, 0.96). Low education level was significantly associated with limited knowledge of transmission through lake water contact (OR = 0.71, 95% CI 0.52, 0.97) and infection from the lake (OR = 0.33, 95% CI 0.19, 0.57). Notably, parents/guardians who have heard of schistosomiasis could not recognize symptoms of S. mansoni infection, such as abdominal pain (91.8%, 815/888) and blood in the stool (85.1%, 756/888). Surprisingly, 49.8% (442/888) incorrectly identified hematuria (blood in urine), a key sign of S. haematobium, but not S. mansoni, in an endemic area for S. mansoni infection. The majority (82.6%, 734/888) of parents/guardians were unaware that dams are potential infection sites, despite 53.9% (479/888) of their pre-school-aged children testing positive for schistosome infection.
CONCLUSIONS
Despite the high level of awareness of intestinal schistosomiasis in the study area, we identified a low level of knowledge regarding its causes, modes of transmission, signs and symptoms and potential sites of transmission within the community. This study emphasizes the need for targeted educational interventions to address the misconceptions and knowledge gaps surrounding intestinal schistosomiasis through tailored community-based programs.
PubMed: 38745247
DOI: 10.1186/s41182-024-00602-7 -
Frontiers in Immunology 2024The parasitic helminth is a potent inducer of type 2 immune responses by stimulating dendritic cells (DCs) to prime T helper 2 (Th2) responses. We previously found that...
The parasitic helminth is a potent inducer of type 2 immune responses by stimulating dendritic cells (DCs) to prime T helper 2 (Th2) responses. We previously found that soluble egg antigens (SEA) promote the synthesis of Prostaglandin E (PGE2) by DCs through ERK-dependent signaling via Dectin-1 and Dectin-2 that subsequently induces OX40L expression, licensing them for Th2 priming, yet the ligands present in SEA involved in driving this response and whether specific targeting of PGE2 synthesis by DCs could affect Th2 polarization are unknown. We here show that the ability of SEA to bind Dectin-2 and drive ERK phosphorylation, PGE2 synthesis, OX40L expression, and Th2 polarization is impaired upon cleavage of high-mannose glycans by Endoglycosidase H treatment. This identifies high-mannose glycans present on glycoproteins in SEA as important drivers of this signaling axis. Moreover, we find that OX40L expression and Th2 induction are abrogated when microsomal prostaglandin E synthase-1 (mPGES) is selectively inhibited, but not when a general COX-1/2 inhibitor is used. This shows that the synthesis of PGE2 is vital for the Th2 priming function of SEA-stimulated DCs as well as points to the potential existence of other COX-dependent lipid mediators that antagonize PGE2-driven Th2 polarization. Lastly, specific PGE2 inhibition following immunization with eggs dampened the egg-specific Th cell response. In summary, our findings provide new insights in the molecular mechanisms underpinning Th2 induction by and identify druggable targets for potential control of helminth driven-Th2 responses.
Topics: Animals; Schistosoma mansoni; Dinoprostone; Th2 Cells; Lectins, C-Type; Mannose; Mice; Polysaccharides; Antigens, Helminth; Dendritic Cells; Schistosomiasis mansoni; Ovum; Mice, Inbred C57BL; OX40 Ligand
PubMed: 38742105
DOI: 10.3389/fimmu.2024.1372927