scholarly journals Schistosoma mansoni Larval Extracellular Vesicle protein 1 (SmLEV1) is an immunogenic antigen found in EVs released from pre-acetabular glands of invading cercariae

2021 ◽  
Vol 15 (11) ◽  
pp. e0009981
Author(s):  
Thomas A. Gasan ◽  
Marije E. Kuipers ◽  
Grisial H. Roberts ◽  
Gilda Padalino ◽  
Josephine E. Forde-Thomas ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Parasite Burden ◽  
Extracellular Vesicle ◽  
Comparative Sequence Analysis ◽  
Metazoan Parasites ◽  
Host Interactions ◽  
Praziquantel Treatment ◽  
Parasite Biology ◽  
Vesicle Protein ◽  
Ige Response

Extracellular Vesicles (EVs) are an integral component of cellular/organismal communication and have been found in the excreted/secreted (ES) products of both protozoan and metazoan parasites. Within the blood fluke schistosomes, EVs have been isolated from egg, schistosomula, and adult lifecycle stages. However, the role(s) that EVs have in shaping aspects of parasite biology and/or manipulating host interactions is poorly defined. Herein, we characterise the most abundant EV-enriched protein in Schistosoma mansoni tissue-migrating schistosomula (Schistosoma mansoni Larval Extracellular Vesicle protein 1 (SmLEV1)). Comparative sequence analysis demonstrates that lev1 orthologs are found in all published Schistosoma genomes, yet homologs are not found outside of the Schistosomatidae. Lifecycle expression analyses collectively reveal that smlev1 transcription peaks in cercariae, is male biased in adults, and is processed by alternative splicing in intra-mammalian lifecycle stages. Immunohistochemistry of cercariae using a polyclonal anti-recombinant SmLEV1 antiserum localises this protein to the pre-acetabular gland, with some disperse localisation to the surface of the parasite. S. mansoni—infected Ugandan fishermen exhibit a strong IgG1 response against SmLEV1 (dropping significantly after praziquantel treatment), with 11% of the cohort exhibiting an IgE response and minimal levels of detectable antigen-specific IgG4. Furthermore, mice vaccinated with rSmLEV1 show a slightly reduced parasite burden upon challenge infection and significantly reduced granuloma volumes, compared with control animals. Collectively, these results describe SmLEV1 as a Schistosomatidae-specific, EV-enriched immunogen. Further investigations are now necessary to uncover the full extent of SmLEV1’s role in shaping schistosome EV function and definitive host relationships.

scholarly journals Comparative sequence analysis reveals regulation of genes in developing schistosomula of Schistosoma mansoni exposed to host portal serum

PLoS ONE ◽  
2017 ◽  
Vol 12 (6) ◽  
pp. e0178829 ◽  
Author(s):  
Wander de Jesus Jeremias ◽  
Flávio Marcos Gomes Araújo ◽  
Fábio Ribeiro Queiroz ◽  
Fabiano Sviatopolk Mirsky Pais ◽  
Ana Carolina Alves de Mattos ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Schistosoma Mansoni ◽  
Comparative Sequence Analysis ◽  
Comparative Sequence

scholarly journals The immunomodulatory activity of Chenopodium ambrosioides reduces the parasite burden and hepatic granulomatous inflammation in Schistosoma mansoni-infection

2021 ◽  
Vol 264 ◽  
pp. 113287 ◽  
Author(s):  
João Gustavo Mendes Rodrigues ◽  
Paula Sibelly Veras Albuquerque ◽  
Johnny R Nascimento ◽  
Jaianna Andressa Viana Campos ◽  
Andressa S S Godinho ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Granulomatous Inflammation ◽  
Parasite Burden ◽  
Immunomodulatory Activity ◽  
Chenopodium Ambrosioides

scholarly journals Daily rhythms in gene expression of the human parasite Schistosoma mansoni

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Kate A. Rawlinson ◽  
Adam J. Reid ◽  
Zhigang Lu ◽  
Patrick Driguez ◽  
Anna Wawer ◽  
...  
Keyword(s):  
Gene Expression ◽  
Schistosoma Mansoni ◽  
Circadian Clock ◽  
Drug Targets ◽  
Clock Genes ◽  
Biological Rhythms ◽  
Active Phase ◽  
Egg Laying ◽  
Daily Rhythms ◽  
Metazoan Parasites

Abstract Background The consequences of the earth’s daily rotation have led to 24-h biological rhythms in most organisms. Even some parasites are known to have daily rhythms, which, when in synchrony with host rhythms, can optimise their fitness. Understanding these rhythms may enable the development of control strategies that take advantage of rhythmic vulnerabilities. Recent work on protozoan parasites has revealed 24-h rhythms in gene expression, drug sensitivity and the presence of an intrinsic circadian clock; however, similar studies on metazoan parasites are lacking. To address this, we investigated if a metazoan parasite has daily molecular oscillations, whether they reveal how these longer-lived organisms can survive host daily cycles over a lifespan of many years and if animal circadian clock genes are present and rhythmic. We addressed these questions using the human blood fluke Schistosoma mansoni that lives in the vasculature for decades and causes the tropical disease schistosomiasis. Results Using round-the-clock transcriptomics of male and female adult worms collected from experimentally infected mice, we discovered that ~ 2% of its genes followed a daily pattern of expression. Rhythmic processes included a stress response during the host’s active phase and a ‘peak in metabolic activity’ during the host’s resting phase. Transcriptional profiles in the female reproductive system were mirrored by daily patterns in egg laying (eggs are the main drivers of the host pathology). Genes cycling with the highest amplitudes include predicted drug targets and a vaccine candidate. These 24-h rhythms may be driven by host rhythms and/or generated by a circadian clock; however, orthologs of core clock genes are missing and secondary clock genes show no 24-h rhythmicity. Conclusions There are daily rhythms in the transcriptomes of adult S. mansoni, but they appear less pronounced than in other organisms. The rhythms reveal temporally compartmentalised internal processes and host interactions relevant to within-host survival and between-host transmission. Our findings suggest that if these daily rhythms are generated by an intrinsic circadian clock then the oscillatory mechanism must be distinct from that in other animals. We have shown which transcripts oscillate at this temporal scale and this will benefit the development and delivery of treatments against schistosomiasis.

scholarly journals Regression of Schistosoma mansoni associated morbidity among Ugandan preschool children following praziquantel treatment: A randomised trial

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259338
Author(s):  
Allen Nalugwa ◽  
Edridah Muheki Tukahebwa ◽  
Annette Olsen ◽  
Fred Nuwaha
Keyword(s):  
Single Dose ◽  
Preschool Children ◽  
Liver Fibrosis ◽  
Schistosoma Mansoni ◽  
Randomised Trial ◽  
Double Dose ◽  
Number Of Children ◽  
Praziquantel Treatment ◽  
Significant Difference ◽  
Liver Enlargement

Preschool children suffer from morbidity attributable to Schistosoma mansoni. We compared a single and double dose of praziquantel treatment on the regression of S. mansoni associated morbidity in children less than six years in Uganda. We measured the sizes of spleen and liver as well as liver fibrosis before treatment and 8 months after treatment among children who either received one dose (n = 201) or two doses (n = 184) of praziquantel (standard oral dose of 40 mg/kg body weight). Heamoglobin measurements were also taken. Overall, liver enlargement reduced from 52.2% (95% CI (Confidence interval) 45.1, 59.3) to 17.9% (95% CI 12.9, 23.9) with a single dose and from 48.4 (95% CI 40.9, 55.8) to 17.9% (95% CI 12.7, 24.3) with a double dose and there was no significant difference between the changes in proportion of children with enlarged liver between the two treatment groups. The proportion of children with enlarged spleen was not significantly reduced in the group treated with either one or two doses, 47.8% (95% CI 41.7, 54.9) to 45.3% (95% CI 38.3, 52.4) and 48.4% (95% CI 40.9,55.8) to 40.8% 95% CI 33.6, 48.2), respectively. Liver fibrosis detected among children getting single dose (n = 9) or double doses (n = 13) resolved after treatment with praziquantel. The number of children with low heamoglobin significantly reduced from 51.2% (95% CI 44.1, 58.3) to 0.5% (0.2, 0.8) and 61.4% (95% CI 53.9,68.5) to 1.1% (95% CI 0.1, 3.9) after single and double dose treatment, respectively. These results suggest that there is no evidence of a difference in effect between one dose of praziquantel and two doses in reversing morbidity attributable to S. mansoni among children less than six years of age.

scholarly journals Plasma levels of innate immune mediators are associated with liver fibrosis in low parasite burden Schistosoma mansoni- infected individuals

2018 ◽  
Vol 87 (3) ◽  
pp. e12642 ◽  
Author(s):  
J. L. Rodrigues Oliveira ◽  
M. M. Teixeira ◽  
J. R. Lambertucci ◽  
C. M. F. Antunes ◽  
M. Carneiro ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Schistosoma Mansoni ◽  
Plasma Levels ◽  
Parasite Burden ◽  
Innate Immune ◽  
Immune Mediators

Altered behaviour of carbohydrate-bound molecules and lipids in areas of the tegument of adult Schistosoma mansoni worms damaged by praziquantel

Parasitology ◽  
1994 ◽  
Vol 109 (4) ◽  
pp. 469-477 ◽  
Author(s):  
S. F. Lima ◽  
L. Q. Vieira ◽  
A. Hardert ◽  
J. R. Kusel
Keyword(s):  
Diffusion Coefficient ◽  
Schistosoma Mansoni ◽  
Surface Properties ◽  
Fluorescent Probes ◽  
Lateral Diffusion ◽  
Praziquantel Treatment ◽  
Fluid Properties ◽  
Altered Surface ◽  
Mobile Fraction ◽  
Lateral Diffusion Coefficient

SUMMARYBy using fluorescent probes the distribution and fluid properties of lipid and saccharide-bound molecules was assessed in the tegument of praziquantel (−) treated Schistosoma mansoni adult male worms. Our results show that higher amounts of glycoproteins and/or glycolipids are exposed in damaged areas of the membrane compared with undamaged ones. At damaged regions these molecules present high lateral diffusion coefficient and mobile fraction values which suggests that after praziquantel(−) treatment they are being shed by the worm into the medium. The lateral diffusion coefficient of the lipid analogue 5'-octadecanoyl aminofluorescein is unchanged in damaged or undamaged areas but the mobile fraction is significantly reduced at damaged areas. The immunological significance of these altered surface properties is discussed.

The suppressive excretory–secretory product of Trichobilharzia ocellata: a possible factor for determining compatibility in parasite–host interactions

Parasitology ◽  
1997 ◽  
Vol 115 (2) ◽  
pp. 193-203 ◽  
Author(s):  
P. E. NÚÑEZ ◽  
M. DE JONG-BRINK
Keyword(s):  
Schistosoma Mansoni ◽  
Post Infection ◽  
Lymnaea Stagnalis ◽  
Secretory Product ◽  
Bacterial Clearance ◽  
Host Interactions ◽  
Specific Manner ◽  
Planorbis Corneus ◽  
Trematode Infections ◽  
Trichobilharzia Ocellata

Factors which may determine trematode–snail interactions were assessed in the present study. Compatibility was examined using a bacterial clearance assay to detect the modulatory effects of both compatible and incompatible trematode infections on the activity of haemocytes from Lymnaea stagnalis, during the early stages of infection. Exposure to and injection with Trichobilharzia ocellata, a compatible trematode, or the incompatible Schistosoma mansoni, resulted in modulation of haemocyte activity. However, T. ocellata activated haemocytes 1·5 h post-infection (p.i.) and then suppressed activity 24–72 h p.i. whereas with S. mansoni no suppression, only activation of haemocytes was observed throughout the test period (1·5–72 h p.i.). In previous studies, modulation of the haemocyte clearance activity by T. ocellata was found to be mediated by 2 E–S fractions, an activating fraction and a suppressing one. Investigations to assess whether the lack of suppression of haemocyte activity, observed in the S. mansoni–L. stagnalis incompatible trematode–snail interaction studied, was due to either the absence or ineffectiveness of the suppressing E–S fraction, were performed on a second incompatible combination, T. ocellata–Planorbis corneus. Using this combination it was revealed that only the activating E–S fraction had modulatory effects on P. corneus haemocytes, indicating that the suppressing E–S fraction, which actively interferes with the clearance activity of haemocytes from L. stagnalis, appears to act in a host-specific manner. In conclusion, the suppressing E–S fraction determines, at least in part, compatibility in the trematode–snail association studied. This is also probably likely in other trematode–snail combinations.

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