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1.
Int J Mol Sci ; 23(3)2022 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-35163381

RESUMO

Schistosoma mansoni uses different mechanisms to escape its host's immunity. Understanding the ability of memory T cells to withstand this pathogen's manipulation is important for the development of effective vaccines against this immunomodulatory pathogen. In this study, ovalbumin (OVA) transgenic S. mansoni is used as a tool to investigate whether fully differentiated Th1, Th2 and Th17 cells are able to withstand pathogen manipulation. Naïve T cells from OT-II T cell receptor transgenic mice with a specificity for OVA were differentiated into Th1, Th2, and Th17 polarised memory cells in vitro. These cells were adoptively transferred into recipient mice to investigate whether these polarised immune memory T cells are resilient in the face of pathogen-mediated manipulation. After transferring memory cells, mice were challenged with OVA-transduced S. mansoni eggs as well as wild-type controls. The in vitro differentiated Th1, Th2 and Th17 memory cells continued to produce the same cytokines when challenged by OVA-expressing S. mansoni eggs as to these they produced when transferred in vivo, suggesting that the Th phenotypes of the memory T cells remains unaltered in the face of stimulation by S. mansoni. The ability of memory T cells to remain resilient to manipulation by the parasite suggests that vaccines might be able to produce immune memory responses able to withstand S. mansoni immune manipulation and hence protect the host from infection.


Assuntos
Imunidade , Schistosoma mansoni/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Transferência Adotiva , Animais , Antígenos/imunologia , Polaridade Celular , Proliferação de Células , Citocinas/metabolismo , Feminino , Memória Imunológica , Linfonodos/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Ovalbumina/imunologia , Óvulo/metabolismo , Esquistossomose mansoni/imunologia , Baço/metabolismo , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia
2.
Parasitol Int ; 86: 102446, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34481947

RESUMO

After many years of the excessive use of praziquantel against Schistosoma mansoni (S. mansoni), it has already led to the development of drug resistance. While schistosomiasis is still affecting millions of people every year, vaccination may be one realistic alternative way to control the disease. Currently, S. mansoni 14-kDa fatty acid-binding protein (Sm14) has shown promising results as a vaccine antigen. Yet, the use of an adjuvant may be necessary to further increase the effectiveness of the vaccine. Herein, we investigated the potential of using heat-killed Cutibacterium acnes (C. acnes) as an adjuvant for recombinant Sm14 (rSm14). Immunization of mice with C. acnes-adjuvanted rSm14 showed increased humoral immune responses, compared with mice immunized with rSm14 alone. Additionally, C. acnes-adjuvanted rSm14 vaccination provided higher protection to mice against S. mansoni infection and liver injuries. These results suggest that C. acnes increases the immunogenicity of rSm14, which leads to better protection against S. mansoni infection. Therefore, heat-killed C. acnes may be a promising adjuvant to use with rSm14.


Assuntos
Proteínas de Transporte de Ácido Graxo/imunologia , Proteínas de Helminto/imunologia , Imunogenicidade da Vacina , Propionibacteriaceae/química , Schistosoma mansoni/imunologia , Esquistossomose mansoni/prevenção & controle , Vacinas/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C
3.
PLoS Negl Trop Dis ; 15(12): e0009486, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34855748

RESUMO

BACKGROUND: Schistosomiasis, caused by Schistosoma mansoni, is of great significance to public health in sub-Saharan Africa. In the Democratic Republic of Congo (DRC), information on the burden of S. mansoni infection is scarce, which hinders the implementation of adequate control measures. We assessed the geographical distribution of S. mansoni infection across Ituri province in north-eastern DRC and determined the prevailing risk factors. METHODS/PRINCIPAL FINDINGS: Two province-wide, community-based studies were conducted. In 2016, a geographical distribution study was carried out in 46 randomly selected villages across Ituri. In 2017, an in-depth study was conducted in 12 purposively-selected villages, across the province. Households were randomly selected, and members were enrolled. In 2016, one stool sample was collected per participant, while in 2017, several samples were collected per participant. S. mansoni eggs were detected using the Kato-Katz technique. In 2017, a point-of-care circulating cathodic S. mansoni antigen (POC-CCA) urine test was the second used diagnostic approach. Household and individual questionnaires were used to collect data on demographic, socioeconomic, environmental, behavioural and knowledge risk factors. Of the 2,131 participants in 2016, 40.0% were positive of S. mansoni infection. Infection prevalence in the villages ranged from 0 to 90.2%. Of the 707 participants in 2017, 73.1% were tested positive for S. mansoni. Prevalence ranged from 52.8 to 95.0% across the health districts visited. Infection prevalence increased from north to south and from west to east. Exposure to the waters of Lake Albert and the villages' altitude above sea level were associated with the distribution. Infection prevalence and intensity peaked in the age groups between 10 and 29 years. Preschool children were highly infected (62.3%). Key risk factors were poor housing structure (odds ratio [OR] 2.1, 95% 95% confidence interval [CI] 1.02-4.35), close proximity to water bodies (OR 1.72, 95% CI 1.1-2.49), long-term residence in a community (OR 1.41, 95% CI 1.11-1.79), lack of latrine in the household (OR 2.00, 95% CI 1.11-3.60), and swimming (OR 2.53, 95% CI 1.20-5.32) and washing (OR 1.75, 95% CI 1.10-2.78) in local water bodies. CONCLUSIONS/SIGNIFICANCE: Our results show that S. mansoni is highly endemic and a major health concern in Ituri province, DRC. Infection prevalence and intensity, and the prevailing socioeconomic, environmental, and behavioural risk factors in Ituri reflect intense exposure and alarming transmission rates. A robust plan of action is urgently needed in the province.


Assuntos
Schistosoma mansoni/patogenicidade , Esquistossomose mansoni/epidemiologia , Adolescente , Adulto , Animais , Anti-Helmínticos/uso terapêutico , Criança , Pré-Escolar , Estudos Transversais , República Democrática do Congo/epidemiologia , Características da Família , Fezes/parasitologia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Schistosoma mansoni/imunologia , Esquistossomose mansoni/tratamento farmacológico , Adulto Jovem
4.
PLoS Negl Trop Dis ; 15(12): e0009375, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34855763

RESUMO

BACKGROUND: Reducing morbidity is the main target of schistosomiasis control efforts, yet only rarely do control programmes assess morbidity linked to Schistosoma sp. infection. In the Democratic Republic of Congo (DRC), and particularly in north-eastern Ituri Province, little is known about morbidity associated with Schistosoma mansoni infection. For this reason, we aimed to assess intestinal and hepatosplenic morbidity associated with S. mansoni infection in Ituri Province. METHODS/PRINCIPAL FINDINGS: In 2017, we conducted a cross-sectional study in 13 villages in Ituri Province, DRC. S. mansoni infection was assessed with a Kato-Katz stool test (2 smears) and a point-of-care circulating cathodic antigen (POC-CCA) urine test. A questionnaire was used to obtain demographic data and information about experienced intestinal morbidity. Each participant underwent an abdominal ultrasonography examination to diagnose hepatosplenic morbidity. Of the 586 study participants, 76.6% tested positive for S. mansoni. Intestinal morbidity reported in the two preceding weeks was very frequent, and included abdominal pain (52.7%), diarrhoea (23.4%) and blood in the stool (21.5%). Hepatosplenic morbidity consisted of abnormal liver parenchyma patterns (42.8%), hepatomegaly (26.5%) and splenomegaly (25.3%). Liver pathology (adjusted odds ratio [aOR] 1.20, 95% confidence interval [CI] 1.06-1.37, p = 0.005) was positively and significantly associated with S. mansoni infection. Hepatomegaly (aOR 1.52, 95% CI 0.99-2.32, p = 0.053) and splenomegaly (aOR 1.12, 95% CI 0.73-1.72, p = 0.619) were positively but not significantly associated with S. mansoni infection at the individual level. At the village level, S. mansoni prevalence was positively associated with the prevalence of hepatomegaly and splenomegaly. High-intensity S. mansoni infections were associated with diarrhoea, blood in the stool, hepatomegaly, splenomegaly, and liver parenchyma (C, D, E and F pathology patterns). Four study participants were diagnosed with ascites and five reported hematemesis. CONCLUSIONS/SIGNIFICANCE: Our study documents a high burden of intestinal and hepatosplenic morbidity associated with S. mansoni infection status in Ituri Province. The findings call for targeted interventions to address both S. mansoni infection and related morbidity.


Assuntos
Schistosoma mansoni/patogenicidade , Esquistossomose mansoni/complicações , Esquistossomose mansoni/epidemiologia , Adolescente , Adulto , Animais , Anti-Helmínticos/uso terapêutico , Anticorpos Anti-Helmínticos/sangue , Criança , Estudos Transversais , República Democrática do Congo/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Morbidade , Prevalência , População Rural/estatística & dados numéricos , Schistosoma mansoni/imunologia , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/imunologia , Esplenomegalia/epidemiologia , Adulto Jovem
5.
Front Immunol ; 12: 748387, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956183

RESUMO

Beyond transient control of the infection, additional benefits of mass drug administration of praziquantel in endemic communities have been suggested in communities but not mechanistically investigated experimentally. The present study sought to evaluate the additional and hitherto unreported benefits of repeated mass drug administration of praziquantel. We used a tractable mouse model of Schistosoma mansoni infection to assess the effects of repeated infection-treatment cycles on the host susceptibility to reinfection. Parasitaemia was assessed by quantification of Schistosoma egg burden in liver tissues and morbidity was followed up by histological observation of liver lesions by microscopy and using biochemical measurement of liver transaminases. Immune responses were further determined by serum probing of schistosoma-specific antibodies, cytokines and quantification of liver cellular and soluble mediator responses by flow cytometry and ELISA, respectively. At similar ages and comparable gender distribution, groups of mice undergoing higher number of infections treatment cycles over a longer period, remained susceptible to reinfection by the parasite, as judged by the presence of eggs and the associated increasing pathology in the liver tissues. However, notably, there was a clear and significantly higher propensity to lower egg burden upon reinfection when compared to counterparts undergoing a lower number of infection-treatment cycles. This relative reduction of susceptibility to infection was paralleled by a more robust humoral response against parasite antigens, elevated serum IL-4 and liver cytokines. Of note, praziquantel treatment of infected mice left them at a higher baseline of serum IL-4, IgE and liver cytokines but lower CD4+ T cell -derived cytokines when compared to infected non-treated mice supporting an immunological treatment-induced advantage of previously infected mice over naïve mice and infected/not treated mice. Notably, repeated infection-treatment cycles did not preclude the infection-driven aggravation of collagen deposition in the livers over time and was corroborated by a more robust local production of inflammatory cytokines in the most exposed livers. Taken together, our data reveal that treatment of S. mansoni-infected hosts with praziquantel rewires the immune system to a conformation less permissive to subsequent reinfection in mice. Provided the data are translatable from mouse to human, our findings may provide mechanistic support to the potential benefits of more frequent MDAs in high transmission areas to allow rapid acquisition of protective immunity against reinfection.


Assuntos
Anti-Helmínticos/farmacologia , Praziquantel/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Esquistossomose mansoni/tratamento farmacológico , Administração Oral , Animais , Anti-Helmínticos/administração & dosagem , Citometria de Fluxo , Camundongos , Camundongos Endogâmicos , Testes de Sensibilidade Parasitária , Praziquantel/administração & dosagem , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Esquistossomose mansoni/parasitologia
6.
Front Immunol ; 12: 779534, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34970264

RESUMO

This is a case series study to evaluate immunological markers associated with schistosomiasis advanced fibrosis, including 69 patients from an endemic area from the State of Sergipe and from the Hepatology Service of the University Hospital in Sergipe, Brazil. Hepatic fibrosis was classified based on Niamey protocol for ultrasonography (US). Immune response to Schistosoma mansoni antigens was evaluated by stimulating peripheral blood mononuclear cells (PBMCs) from these patients with either adult worm (SWAP-10 µg/ml) or egg (SEA-10 µg/ml) antigens or purified protein derivative of turberculin (PPD-10 µg/ml) or phytohemagglutinin (PHA-1 µg/ml) for 72 h. The levels of IFN-γ, TNF-α, IL-5, IL-10, and IL-17 were measured in these supernatants by ELISA and IL-9 by Luminex. Single nucleotide polymorphisms in IL-17, IL10, and CD209 genes were genotyped using TaqMan probe by qPCR. Higher levels of IL-9, IL-10, and IL-17 were found in PBMC supernatants of patients with advanced hepatic fibrosis. Direct correlations were detected between IL-9 and IL-17 levels with US spleen sizes, portal vein diameters, and periportal thickening. The CD209 rs2287886 AG polymorphism patients produce higher IL-17 levels. Together, these data suggest a role of these cytokines in the immunopathogenesis of advanced fibrosis in human schistosomiasis.


Assuntos
Antígenos de Helmintos/imunologia , Interleucina-10/metabolismo , Interleucina-17/metabolismo , Interleucina-9/metabolismo , Leucócitos Mononucleares/metabolismo , Cirrose Hepática/sangue , Schistosoma mansoni/imunologia , Esquistossomose mansoni/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Biomarcadores/metabolismo , Estudos de Casos e Controles , Moléculas de Adesão Celular/genética , Células Cultivadas , Criança , Feminino , Interações Hospedeiro-Parasita , Humanos , Interleucina-10/genética , Interleucina-17/genética , Lectinas Tipo C/genética , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/parasitologia , Cirrose Hepática/imunologia , Cirrose Hepática/parasitologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Receptores de Superfície Celular/genética , Schistosoma mansoni/patogenicidade , Esquistossomose mansoni/genética , Esquistossomose mansoni/imunologia , Esquistossomose mansoni/parasitologia , Adulto Jovem
7.
Am J Trop Med Hyg ; 106(1): 303-311, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34749308

RESUMO

The WHO guidelines for monitoring and evaluating Schistosoma mansoni control programs are based on the Kato-Katz (KK) fecal examination method; however, there are limitations to its use, particularly in low prevalence areas. The point-of-care urine circulating cathodic antigen (POC-CCA) assay has emerged as a useful tool for mapping schistosomiasis prevalence, but its use in monitoring and evaluating control programs has not been evaluated. Before POC-CCA can be used for these programs, it must be determined how previous guidance based on the KK method can be translated to the POC-CCA assay; furthermore, its performance in different endemicity settings must be evaluated. Urine and stool specimens were collected from students attending public primary schools in western Kenya before mass treatment with praziquantel at baseline (51 schools), year 1 (45 schools), year 2 (34 schools), and year 3 (20 schools). Prevalence and infection intensity were determined by the KK method and POC-CCA assay. Changes in prevalence and intensity were compared within the strata of schools grouped according to the baseline prevalence determined by the KK method (0-10%, > 10-20%, > 20%). The prevalence determined by the POC-CCA assay was higher than that determined by the KK method at all time points for all strata. The prevalence determined by the KK method decreased from baseline to 2 and 3 years, as did infection intensity (with one exception). A corresponding decrease was not always replicated by the POC-CCA assay results. The POC-CCA assay did not perform as expected, and the concordance of results of the two tests was poor. Furthermore, there are emerging concerns regarding the specificity of the POC-CCA assay. Therefore, it is impossible to translate historical data and programmatic guidelines based on the KK method results to the POC-CCA assay.


Assuntos
Antígenos de Helmintos/urina , Administração Massiva de Medicamentos/normas , Sistemas Automatizados de Assistência Junto ao Leito/normas , Schistosoma mansoni/imunologia , Esquistossomose mansoni/tratamento farmacológico , Animais , Anti-Helmínticos/uso terapêutico , Fezes/parasitologia , Humanos , Quênia/epidemiologia , Administração Massiva de Medicamentos/métodos , Praziquantel/uso terapêutico , Prevalência , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/prevenção & controle , Esquistossomose mansoni/urina
8.
PLoS Negl Trop Dis ; 15(11): e0009981, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34793443

RESUMO

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.


Assuntos
Cercárias/imunologia , Vesículas Extracelulares/imunologia , Proteínas de Helminto/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/parasitologia , Adolescente , Adulto , Sequência de Aminoácidos , Animais , Anti-Helmínticos/administração & dosagem , Anticorpos Anti-Helmínticos/imunologia , Cercárias/genética , Cercárias/crescimento & desenvolvimento , Criança , Estudos de Coortes , Vesículas Extracelulares/genética , Feminino , Proteínas de Helminto/administração & dosagem , Proteínas de Helminto/química , Proteínas de Helminto/genética , Humanos , Imunogenicidade da Vacina , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Masculino , Camundongos , Pessoa de Meia-Idade , Praziquantel/administração & dosagem , Schistosoma mansoni/química , Schistosoma mansoni/genética , Schistosoma mansoni/crescimento & desenvolvimento , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/imunologia , Alinhamento de Sequência , Vacinas/administração & dosagem , Vacinas/genética , Vacinas/imunologia , Adulto Jovem
9.
PLoS Negl Trop Dis ; 15(10): e0009866, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34644290

RESUMO

Extracellular vesicles (EVs) are protein-loaded nano-scaled particles that are extracellularly released by eukaryotes and prokaryotes. Parasite's EVs manipulate the immune system, making them probable next-generation vaccines. Schistosomal EVs carry different proteins of promising immunizing potentials. For evaluating the immune-protective role of Schistosoma mansoni (S. mansoni) egg-derived EVs against murine schistosomiasis, EVs were isolated from cultured S. mansoni eggs by progressive sequential cooling ultra-centrifugation technique. Isolated EVs were structurally identified using transmission electron microscope and their protein was quantified by Lowry's technique. Experimental mice were subcutaneously immunized with three doses of 20 µg EVs (with or without alum adjuvant); every two weeks, then were challenged with S. mansoni cercariae two weeks after the last immunizing dose. Six weeks post infection, mice were sacrificed for vaccine candidate assessment. EVs protective efficacy was evaluated through parasitological, histopathological, and immunological parameters. Results showed significant reduction of tegumentally deranged adult worms, hepatic and intestinal egg counts reduction by 46.58%, 93.14% and 93.17% respectively, accompanied by remarkable amelioration of sizes, numbers and histopathology of hepatic granulomata mediated by high interferon gamma (IFN γ) and antibody level. Using sera from vaccinated mice, the molecular weight of EVs' protein components targeted by the antibody produced was recognized by western immunoblot. Results revealed two bands of ~ 14 KDa and ~ 21 KDa, proving that EVs are able to stimulate specific antibodies response. In conclusion, the present study highlighted the role of S. mansoni-egg derived EVs as a potential vaccine candidate against murine schistosomiasis mansoni.


Assuntos
Vesículas Extracelulares/imunologia , Óvulo/imunologia , Schistosoma mansoni/imunologia , Vacinas/imunologia , Animais , Anticorpos Anti-Helmínticos/imunologia , Vesículas Extracelulares/genética , Feminino , Humanos , Imunização , Intestinos/imunologia , Intestinos/parasitologia , Masculino , Camundongos , Contagem de Ovos de Parasitas , Schistosoma mansoni/genética , Esquistossomose mansoni/imunologia , Esquistossomose mansoni/parasitologia , Esquistossomose mansoni/prevenção & controle , Vacinas/administração & dosagem
10.
Immunohorizons ; 5(8): 721-732, 2021 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-34462311

RESUMO

Plasmacytoid dendritic cells (pDCs) are potent producers of type I IFN (IFN-I) during viral infection and respond to IFN-I in a positive feedback loop that promotes their function. IFN-I shapes dendritic cell responses during helminth infection, impacting their ability to support Th2 responses. However, the role of pDCs in type 2 inflammation is unclear. Previous studies have shown that pDCs are dispensable for hepatic or splenic Th2 responses during the early stages of murine infection with the trematode Schistosoma mansoni at the onset of parasite egg laying. However, during S. mansoni infection, an ongoing Th2 response against mature parasite eggs is required to protect the liver and intestine from acute damage and how pDCs participate in immune responses to eggs and adult worms in various tissues beyond acute infection remains unclear. We now show that pDCs are required for optimal Th2 cytokine production in response to S. mansoni eggs in the intestinal-draining mesenteric lymph nodes throughout infection and for egg-specific IFN-γ at later time points of infection. Further, pDC depletion at chronic stages of infection led to increased hepatic and splenic pathology as well as abrogated Th2 cell cytokine production and activation in the liver. In vitro, mesenteric lymph node pDCs supported Th2 cell responses from infection-experienced CD4+ T cells, a process dependent on pDC IFN-I responsiveness, yet independent of Ag. Together, these data highlight a previously unappreciated role for pDCs and IFN-I in maintaining and reinforcing type 2 immunity in the lymph nodes and inflamed tissue during helminth infection.


Assuntos
Citocinas/imunologia , Células Dendríticas/imunologia , Ativação Linfocitária/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/parasitologia , Citocinas/metabolismo , Células Dendríticas/parasitologia , Feminino , Citometria de Fluxo/métodos , Interações Hospedeiro-Parasita/imunologia , Contagem de Linfócitos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Schistosoma mansoni/fisiologia , Esquistossomose mansoni/metabolismo , Esquistossomose mansoni/parasitologia , Linfócitos T Auxiliares-Indutores/metabolismo , Linfócitos T Auxiliares-Indutores/parasitologia , Células Th2/imunologia , Células Th2/metabolismo , Células Th2/parasitologia
11.
Acta Trop ; 222: 106033, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34224719

RESUMO

Sm28GST is one of the candidate antigens for Schistosoma mansoni vaccine. Already Sm28GST vaccine formulations have shown to be protective against S. mansoni infection. Currently, efforts have been put into finding an adjuvant to enhance the immunity induced by Sm28GST. In the present work, we investigated whether heat-killed Propionibacterium acnes can be served as a potential adjuvant for recombinant Sm28GST (rSm28GST) antigen. As the results showed, P. acnes successfully modulated the Th1 humoral immune response induced by rSm28GST. Stronger Th1 cytokines responses were also observed in mice immunized with P. acnes-adjuvanted rSm28GST. Immunization of mice with P. acnes-adjuvanted rSm28GST was able to reduce worm burden and hepatic egg burden by 54.20 and 73.61%. Reduced granuloma size and count, as well as improved liver histology, were seen in P. acnes-adjuvanted rSm28GST immunized mice. These data suggest that P. acnes may evoke a stronger rSm28GST-induced immune response, higher resistance to S. mansoni infection, and more profound protection against S. mansoni-induced liver damages.


Assuntos
Antígenos de Helmintos/imunologia , Glutationa Transferase/imunologia , Propionibacterium acnes , Esquistossomose mansoni , Vacinas/imunologia , Adjuvantes Imunológicos , Animais , Anticorpos Anti-Helmínticos , Temperatura Alta , Camundongos , Schistosoma mansoni/imunologia , Esquistossomose mansoni/prevenção & controle , Células Th1/imunologia
12.
Am J Trop Med Hyg ; 105(3): 677-683, 2021 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-34280143

RESUMO

In low-endemicity settings, current tools for the diagnosis and surveillance of schistosomiasis are often inaccurate in detecting true infection. We assessed the accuracy of an up-converting phosphor lateral flow circulating anodic antigen (UCP-LF CAA) test and a point-of-care circulating cathodic antigen (POC-CCA) urine cassette test for the diagnosis of Schistosoma mansoni. Our study was conducted in eight schools of western Côte d'Ivoire. Fifty children, aged 9-12 years, were enrolled per school. From each child, a single urine specimen and two stool specimens were collected over consecutive days for diagnostic work-up. Urine samples were subjected to UCP-LF CAA and POC-CCA tests. From each stool sample, triplicate Kato-Katz thick smears were examined. Overall, 378 children had complete data records. The prevalence of S. mansoni, as assessed by six Kato-Katz thick smears, was 4.0%. The UCP-LF CAA and POC-CCA tests revealed S. mansoni prevalence of 25.4% and 30.7%, respectively, when considering trace results as positive, and prevalence of 23.3% and 10.9% when considering trace results as negative. In the latter case, based on a composite "gold" standard, the sensitivity of UCP-LF CAA (80.7%) was considerably higher than that of POC-CCA (37.6%) and six Kato-Katz thick smears (13.8%). The negative predictive value of UCP-LF CAA, POC-CCA, and six Kato-Katz thick smears was 92.8%, 79.8%, and 74.1%, respectively. Our results confirm that UCP-LF CAA is more accurate than Kato-Katz and POC-CCA for the diagnosis of S. mansoni in low-endemicity settings.


Assuntos
Antígenos de Helmintos/urina , Glicoproteínas/urina , Proteínas de Helminto/urina , Schistosoma mansoni/imunologia , Esquistossomose mansoni/diagnóstico , Animais , Criança , Costa do Marfim , Fezes/parasitologia , Feminino , Humanos , Masculino , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/urina , Sensibilidade e Especificidade , Estudos Soroepidemiológicos , Testes Sorológicos , Urina/parasitologia
14.
Mol Biotechnol ; 63(11): 983-991, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34165770

RESUMO

Schistosomiasis causes significant morbidity and mortality. Vaccine efforts to date indicate the need to increase the immunogenicity of Schistosoma antigens. The multiple antigen-presenting system, whereby proteins are genetically fused to rhizavidin and affinity linked to biotinylated templates, enables the generation of robust immune responses. The objective of this work was to express and purify the S. mansoni antigens, SmTSP-2 and SmCD59.2, in fusion with rhizavidin. The fusion with rhizavidin greatly decreased the expression level of rSmTSP-2, but not rSmCD59.2, and both were expressed in the insoluble fraction, requiring optimization of culture conditions. Evaluation of different E. coli strains and media showed that BL21-DE3 cultured in Terrific Broth provided the highest expression levels of both proteins. Investigation of a range of time and temperature of induction showed that E. coli strains expressing rRzv:SmTSP-2 and rRzv:SmCD59.2 showed the highest protein production at 23 °C for 15 h. Recombinant proteins were purified by a single step of affinity chromatography allowing isolation of these proteins in high concentration and purity. The optimization process increased final soluble protein yield of rRzv:SmTSP-2 by fourfold and rRzv:SmCD59.2 by tenfold, providing ~ 20 mg/L of each protein. Optimized fusion protein production will allow antigen use in biotin-rhizavidin affinity platforms.


Assuntos
Antígenos de Helmintos/biossíntese , Proteínas de Bactérias/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Schistosoma mansoni/metabolismo , Esquistossomose mansoni/imunologia , Animais , Antígenos de Helmintos/genética , Antígenos de Helmintos/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Cromatografia de Afinidade/métodos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Schistosoma mansoni/química , Schistosoma mansoni/imunologia , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/metabolismo , Esquistossomose mansoni/parasitologia
15.
Front Immunol ; 12: 635622, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33968028

RESUMO

Introduction: Schistosomiasis is a neglected tropical disease (NTD) caused by blood-dwelling flatworms which develop from skin-penetrating cercariae, the freely swimming water-borne infective stage of Schistosoma mansoni, into adult worms. This natural course of infection can be mimicked in experimental mouse models of schistosomiasis. However, only a maximum of 20-30% of penetrated cercariae mature into fecund adults. The reasons for this are unknown but could potentially involve soluble factors of the innate immune system, such as complement factors and preexisting, natural antibodies. Materials and Methods: Using our recently developed novel serum- and cell-free in vitro culture system for newly transformed schistosomula (NTS), which supports long-term larval survival, we investigated the effects of mouse serum and its major soluble complement factors C1q, C3, C4 as well as preexisting, natural IgM in vitro and assessed worm development in vivo by infecting complement and soluble (s)IgM-deficient animals. Results: In contrast to sera from humans and a broad variety of mammalian species, serum from mice, surprisingly, killed parasites already at skin stage in vitro. Interestingly, the most efficient killing component(s) were heat-labile but did not include important members of the perhaps best known family of heat-labile serum factors, the complement system, nor consisted of complement-activating natural immunoglobulins. Infection of complement C1q and sIgM-deficient mice with S. mansoni as well as in vitro tests with sera from mice deficient in C3 and C4 revealed no major role for these soluble factors in vivo in regard to parasite maturation, fecundity and associated immunopathology. Rather, the reduction of parasite maturation from cercariae to adult worms was comparable to wild-type mice. Conclusion: This study reveals that not yet identified heat-labile serum factors are major selective determinants of the host-specificity of schistosomiasis, by directly controlling schistosomal development and survival.


Assuntos
Proteínas do Sistema Complemento/metabolismo , Imunoglobulina M/sangue , Schistosoma mansoni/crescimento & desenvolvimento , Esquistossomose mansoni/sangue , Esquistossomose mansoni/parasitologia , Animais , Complemento C1q/genética , Complemento C1q/metabolismo , Complemento C3/genética , Complemento C3/metabolismo , Complemento C4/genética , Complemento C4/metabolismo , Proteínas do Sistema Complemento/genética , Modelos Animais de Doenças , Feminino , Interações Hospedeiro-Parasita , Humanos , Macaca mulatta , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Especificidade da Espécie
16.
Front Immunol ; 12: 624736, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34054799

RESUMO

Acute schistosomiasis (AS) manifests with a broad spectrum of clinical features in pediatric populations. Diagnosis may be difficult in the absence of detectable numbers of eggs. As a result, new approaches may be required to achieve an accurate diagnosis. Optimal praziquantel (PZQ) treatment regimen for young children is debatable. Also, the post-treatment response is still poorly evaluated due to the lack of reliable markers. A group of 6 children (a toddler and 5 pre-school children) and one pre-adolescent were investigated for AS clinical manifestations and followed-up for two years after treatment. Ova detection was performed by Kato-Katz (KK) and presence of Schistosoma mansoni DNA was assessed by real-time PCR (rt-PCR) in stool samples. IgG and IgE anti-Schistosoma levels and urinary antigen were detected by ELISA and point-of-care circulating cathodic antigen (POC-CCA) testing in serum and urine, respectively. AS clinical symptoms were present in 5/7 (71.4%) of the infected children, and hypereosinophilia was detected in all of them. Ova detection and serology were positive in only 3/7 (44.9%) and 4/7 (57.1%), respectively. However, real-time PCR (rt-PCR) showed the presence of Schistosoma DNA in 6/7 (85.7%) of the cases, and urinary antigen was detected in all infected children. The long-term follow-up after treatment with three doses of PZQ (80mg/kg/dose), showed high cure rates (CR) as demonstrated by the DNA-based assay as well as reduced levels of side effects. CR based on urinary antigen detection ranged from 28.6 to 100%, being the highest CR due to double testing the 2-year post-treatment samples. The results suggest that high dose and repeated treatment with PZQ might be effective for AS in young children. Also, new laboratory markers should be considered to diagnosis and monitor the drug response.


Assuntos
Anti-Helmínticos/uso terapêutico , Parasitologia , Praziquantel/uso terapêutico , Schistosoma mansoni/efeitos dos fármacos , Esquistossomose mansoni/diagnóstico , Esquistossomose mansoni/tratamento farmacológico , Adolescente , Animais , Anticorpos Anti-Helmínticos/sangue , Antígenos de Helmintos/urina , Biomarcadores/sangue , Biomarcadores/urina , Pré-Escolar , DNA de Helmintos/genética , Ensaio de Imunoadsorção Enzimática , Fezes/parasitologia , Feminino , Glicoproteínas/urina , Proteínas de Helminto/urina , Humanos , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Lactente , Masculino , Contagem de Ovos de Parasitas , Testes Imediatos , Valor Preditivo dos Testes , Reação em Cadeia da Polimerase em Tempo Real , Schistosoma mansoni/genética , Schistosoma mansoni/imunologia , Esquistossomose mansoni/parasitologia , Testes Sorológicos , Resultado do Tratamento
17.
Sci Rep ; 11(1): 10530, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006964

RESUMO

The study aimed to determine the potential of schistosomula crude antigen (SCA) as a diagnostic target for anti-S. mansoni antibody detection. Cercariae were transformed into schistosomula, homogenized through sonication, and then centrifuged to obtain the SCA. SCA was evaluated using ELISA and dot blots immunoassays on 30 S. mansoni infected sera samples obtained from chronic patients and 30 non-infected humans' sera samples. Either Kato-Katz or saline gradient method or both were employed as the diagnostic reference. Dot blots immunoassay was further performed on protein eluted from 10 to 12 kDa immunoreactive band identified by Western blot analysis. The area under the ROC curve was 0.95 (AUC 0.95, CI 0.88-1.01, p < 0.0001). The sensitivity and specificity of SCA-ELISA and dot blots assays were 96.67% and 86.67% respectively. The human IgG-specific response against SCA was significantly higher in S. mansoni infected individuals (OD = 0.678 ± 0.249) compared to the non-infected population (OD = 0.235 ± 0.136) (p < 0.0001). Our study showed that SCA and its 10-12 kDa component could be useful as diagnostic tools for chronic schistosomiasis.


Assuntos
Antígenos de Helmintos/sangue , Schistosoma mansoni/imunologia , Esquistossomose mansoni/diagnóstico , Adolescente , Adulto , Idoso , Animais , Western Blotting , Estudos de Casos e Controles , Criança , Pré-Escolar , Eletroforese em Gel de Poliacrilamida , Doenças Endêmicas , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Esquistossomose mansoni/imunologia , Sensibilidade e Especificidade , Adulto Jovem
18.
PLoS Negl Trop Dis ; 15(4): e0009369, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33909616

RESUMO

The scientific community identified non stool-based biomarkers as the way forward to support soil-transmitted helminth (STH; Ascaris lumbricoides, Trichuris trichiura and the hookworms Ancylostoma duodenale and Necator americanus) and schistosome (S. mansoni and S. haematobium) deworming programs. This support is needed in making the decision of whether or not to stop preventive chemotherapy intervention efforts and to ultimately transition towards a post-intervention surveillance phase. We applied a two-step micro-array approach to identify antigenic linear epitopes in the STH and S. mansoni proteomes. In a first experiment, we identified antigenic peptides by applying sera from 24 STH and/or S. mansoni infected Ethiopian children on a high-density peptide microarray containing 3.3 million peptides derived from the complete STH and S. mansoni proteomes. A second array experiment with 170,185 peptides that were recognized in the first array was designed to identify non-specific antibody reactivity by applying sera from 24 healthy individuals from Belgium (a non-endemic country). From this array testing cascade, several peptides were identified for STH but none of them appeared to be unique for one species. We therefore concluded that for STH, none of the peptides revealed to be sufficiently sensitive or species specific. For S. mansoni, some promising peptides were identified prompting future investigation. Based on these results, it is unlikely that linear epitopes would be highly useful in detecting species-specific antibody responses to STH in endemic communities. For S. mansoni, one particular peptide of the micro-exon gene 12 (MEG-12) protein deserves further research. In addition, this study emphasizes the need of well-characterized biobanks for biomarker discovery, particularly when the integration of multiple disease programs is envisioned.


Assuntos
Antígenos de Helmintos/análise , Peptídeos/análise , Proteoma/análise , Solo/parasitologia , Adolescente , Animais , Bélgica , Criança , Fezes/parasitologia , Feminino , Helmintíase/tratamento farmacológico , Helmintíase/epidemiologia , Helmintíase/parasitologia , Helmintos/imunologia , Helmintos/isolamento & purificação , Humanos , Masculino , Administração Massiva de Medicamentos , Contagem de Ovos de Parasitas , Schistosoma mansoni/imunologia , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/parasitologia , Especificidade da Espécie
19.
PLoS Negl Trop Dis ; 15(3): e0009200, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33657133

RESUMO

Control of the neglected tropical disease schistosomiasis relies almost entirely on praziquantel (PZQ) monotherapy. How PZQ clears parasite infections remains poorly understood. Many studies have examined the effects of PZQ on worms cultured in vitro, observing outcomes such as muscle contraction. However, conditions worms are exposed to in vivo may vary considerably from in vitro experiments given the short half-life of PZQ and the importance of host immune system engagement for drug efficacy in animal models. Here, we investigated the effects of in vivo PZQ exposure on Schistosoma mansoni. Measurement of pro-apoptotic caspase activation revealed that worm death occurs only after parasites shift from the mesenteric vasculature to the liver, peaking 24 hours after drug treatment. This indicates that PZQ is not directly schistocidal, since PZQ's half-life is ~2 hours in humans and ~30 minutes in mice, and focuses attention on parasite interactions with the host immune system following the shift of worms to the liver. RNA-Seq of worms harvested from mouse livers following sub-lethal PZQ treatment revealed drug-evoked changes in the expression of putative immunomodulatory and anticoagulant gene products. Several of these gene products localized to the schistosome esophagus and may be secreted into the host circulation. These include several Kunitz-type protease inhibitors, which are also found in the secretomes of other blood feeding animals. These transcriptional changes may reflect mechanisms of parasite immune-evasion in response to chemotherapy, given the role of complement-mediated attack and the host innate/humoral immune response in parasite elimination. One of these isoforms, SmKI-1, has been shown to exhibit immunomodulatory and anti-coagulant properties. These data provide insight into the effect of in vivo PZQ exposure on S. mansoni, and the transcriptional response of parasites to the stress of chemotherapy.


Assuntos
Anti-Helmínticos/farmacologia , Praziquantel/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Transcrição Genética/efeitos dos fármacos , Animais , Anti-Helmínticos/administração & dosagem , Feminino , Fígado/parasitologia , Camundongos , Doenças Negligenciadas , Praziquantel/administração & dosagem , Schistosoma mansoni/genética , Schistosoma mansoni/imunologia , Schistosoma mansoni/metabolismo , Esquistossomose mansoni/imunologia
20.
Front Immunol ; 12: 621706, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33737928

RESUMO

Schistosomiasis remains a serious health issue nowadays for an estimated one billion people in 79 countries around the world. Great efforts have been made to identify good vaccine candidates during the last decades, but only three molecules reached clinical trials so far. The reverse vaccinology approach has become an attractive option for vaccine design, especially regarding parasites like Schistosoma spp. that present limitations for culture maintenance. This strategy also has prompted the construction of multi-epitope based vaccines, with great immunological foreseen properties as well as being less prone to contamination, autoimmunity, and allergenic responses. Therefore, in this study we applied a robust immunoinformatics approach, targeting S. mansoni transmembrane proteins, in order to construct a chimeric antigen. Initially, the search for all hypothetical transmembrane proteins in GeneDB provided a total of 584 sequences. Using the PSORT II and CCTOP servers we reduced this to 37 plasma membrane proteins, from which extracellular domains were used for epitope prediction. Nineteen common MHC-I and MHC-II binding epitopes, from eight proteins, comprised the final multi-epitope construct, along with suitable adjuvants. The final chimeric multi-epitope vaccine was predicted as prone to induce B-cell and IFN-γ based immunity, as well as presented itself as stable and non-allergenic molecule. Finally, molecular docking and molecular dynamics foresee stable interactions between the putative antigen and the immune receptor TLR 4. Our results indicate that the multi-epitope vaccine might stimulate humoral and cellular immune responses and could be a potential vaccine candidate against schistosomiasis.


Assuntos
Antígenos de Helmintos/imunologia , Linfócitos B/imunologia , Epitopos Imunodominantes/imunologia , Informática Médica/métodos , Proteínas de Membrana/imunologia , Proteínas Recombinantes de Fusão/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Vacinas/imunologia , Animais , Antígenos de Helmintos/genética , Biologia Computacional , Mapeamento de Epitopos , Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Imunidade Celular , Imunidade Humoral , Epitopos Imunodominantes/genética , Interferon gama/metabolismo , Ativação Linfocitária , Proteínas de Membrana/genética , Simulação de Acoplamento Molecular , Ligação Proteica , Proteínas Recombinantes de Fusão/genética , Receptor 4 Toll-Like/metabolismo , Vacinas/genética , Vacinas de Subunidades , Vacinologia
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