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1.
Front Immunol ; 15: 1372957, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38779688

RESUMO

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-ß, 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 Schistosoma exposure, the CCR2+ IM subpopulation expanded, suggestive of circulating monocyte recruitment. Schistosoma 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: Schistosoma-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-ß and causes PH.


Assuntos
Hipertensão Pulmonar , Macrófagos , Animais , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/parasitologia , Hipertensão Pulmonar/imunologia , Hipertensão Pulmonar/patologia , Camundongos , Macrófagos/imunologia , Macrófagos/parasitologia , Fenótipo , Schistosoma mansoni/imunologia , Camundongos Endogâmicos C57BL , Esquistossomose/imunologia , Esquistossomose/complicações , Esquistossomose/parasitologia , Modelos Animais de Doenças , Esquistossomose mansoni/imunologia , Esquistossomose mansoni/parasitologia , Esquistossomose mansoni/complicações , Esquistossomose mansoni/patologia , Trombospondina 1/genética , Trombospondina 1/metabolismo , Monócitos/imunologia , Receptores CCR2/genética , Receptores CCR2/metabolismo , Feminino , Schistosoma/imunologia , Schistosoma/fisiologia , Pulmão/imunologia , Pulmão/parasitologia , Pulmão/patologia
2.
PLoS Pathog ; 17(12): e1010064, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34969052

RESUMO

Schistosomes are long lived, intravascular parasitic platyhelminths that infect >200 million people globally. The molecular mechanisms used by these blood flukes to dampen host immune responses are described in this review. Adult worms express a collection of host-interactive tegumental ectoenzymes that can cleave host signaling molecules such as the "alarmin" ATP (cleaved by SmATPDase1), the platelet activator ADP (SmATPDase1, SmNPP5), and can convert AMP into the anti-inflammatory mediator adenosine (SmAP). SmAP can additionally cleave the lipid immunomodulator sphingosine-1-phosphate and the proinflammatory anionic polymer, polyP. In addition, the worms release a barrage of proteins (e.g., SmCB1, SjHSP70, cyclophilin A) that can impinge on immune cell function. Parasite eggs also release their own immunoregulatory proteins (e.g., IPSE/α1, omega1, SmCKBP) as do invasive cercariae (e.g., Sm16, Sj16). Some schistosome glycans (e.g., LNFPIII, LNnT) and lipids (e.g., Lyso-PS, LPC), produced by several life stages, likewise affect immune cell responses. The parasites not only produce eicosanoids (e.g., PGE2, PGD2-that can be anti-inflammatory) but can also induce host cells to release these metabolites. Finally, the worms release extracellular vesicles (EVs) containing microRNAs, and these too have been shown to skew host cell metabolism. Thus, schistosomes employ an array of biomolecules-protein, lipid, glycan, nucleic acid, and more, to bend host biochemistry to their liking. Many of the listed molecules have been individually shown capable of inducing aspects of the polarized Th2 response seen following infection (with the generation of regulatory T cells (Tregs), regulatory B cells (Bregs) and anti-inflammatory, alternatively activated (M2) macrophages). Precisely how host cells integrate the impact of these myriad parasite products following natural infection is not known. Several of the schistosome immunomodulators described here are in development as novel therapeutics against autoimmune, inflammatory, and other, nonparasitic, diseases.


Assuntos
Proteínas de Helminto/imunologia , Fatores Imunológicos/imunologia , Schistosoma/imunologia , Esquistossomose/imunologia , Animais , Humanos
3.
Front Immunol ; 12: 634138, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34220800

RESUMO

Schistosomiasis is a parasitic disease endemic to freshwater areas of Southeast Asia, Africa, and South America that is capable of causing serious damage to the internal organs. Recent studies have linked exosomes to the progression of schistosomiasis. These structures are important mediators for intercellular communication, assist cells to exchange proteins, lipids, and genetic material and have been shown to play critical roles during host-parasite interactions. This review aims to discuss the pathophysiology of exosomes in schistosomiasis and their roles in regulating the host immune response. Understanding how exosomes are involved in the pathogenesis of schistosomiasis may provide new perspectives in diagnosing and treating this neglected disease.


Assuntos
Exossomos/parasitologia , Schistosoma/patogenicidade , Esquistossomose/parasitologia , Animais , Exossomos/imunologia , Exossomos/metabolismo , Exossomos/transplante , Interações Hospedeiro-Patógeno , Humanos , Prognóstico , Vacinas Protozoárias/uso terapêutico , Schistosoma/efeitos dos fármacos , Schistosoma/imunologia , Esquistossomose/imunologia , Esquistossomose/metabolismo , Esquistossomose/prevenção & controle , Esquistossomicidas/uso terapêutico , Transdução de Sinais
4.
Int J Mol Sci ; 22(13)2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34281269

RESUMO

The host-parasite schistosome relationship relies heavily on the interplay between the strategies imposed by the schistosome worm and the defense mechanisms the host uses to counter the line of attack of the parasite. The ultimate goal of the schistosome parasite entails five important steps: evade elimination tactics, survive within the human host, develop into adult forms, propagate in large numbers, and transmit from one host to the next. The aim of the parasitized host on the other hand is either to cure or limit infection. Therefore, it is a battle between two conflicting aspirations. From the host's standpoint, infection accompanies a plethora of immunological consequences; some are set in place to defend the host, while most end up promoting chronic disease, which ultimately crosses paths with oxidative stress and cancer. Understanding these networks provides attractive opportunities for anti-schistosome therapeutic development. Hence, this review discusses the mechanisms by which schistosomes modulate the human immune response with ultimate links to oxidative stress and genetic instability.


Assuntos
Citocinas/metabolismo , Interações Hospedeiro-Parasita/imunologia , Esquistossomose/imunologia , Esquistossomose/metabolismo , Animais , Linfócitos B Reguladores/imunologia , Basófilos/imunologia , Células Dendríticas/imunologia , Eosinófilos/imunologia , Humanos , Macrófagos/imunologia , Mastócitos/imunologia , MicroRNAs/imunologia , Modelos Imunológicos , Estresse Oxidativo , Schistosoma/imunologia , Schistosoma/patogenicidade , Esquistossomose/parasitologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia
5.
Front Immunol ; 12: 661241, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34122419

RESUMO

As a relatively successful pathogen, several parasites can establish long-term infection in host. This "harmonious symbiosis" status relies on the "precise" manipulation of host immunity and metabolism, however, the underlying mechanism is still largely elusive. Immunometabolism is an emerging crossed subject in recent years. It mainly discusses the regulatory mechanism of metabolic changes on reprogramming the key transcriptional and post-transcriptional events related to immune cell activation and effect, which provides a novel insight for understanding how parasites regulate the infection and immunity in hosts. The present study reviewed the current research progress on metabolic reprogramming mechanism exploited by parasites to modulate the function in various immune cells, highlighting the future exploitation of key metabolites or metabolic events to clarify the underlying mechanism of anti-parasite immunity and design novel intervention strategies against parasitic infection.


Assuntos
Células Dendríticas/imunologia , Linfócitos/imunologia , Macrófagos/imunologia , Doenças Parasitárias/imunologia , Plasmodium/imunologia , Schistosoma/imunologia , Trypanosoma/imunologia , Animais , Células Dendríticas/metabolismo , Células Dendríticas/parasitologia , Interações Hospedeiro-Parasita/imunologia , Humanos , Linfócitos/metabolismo , Linfócitos/parasitologia , Macrófagos/metabolismo , Macrófagos/parasitologia , Doenças Parasitárias/metabolismo , Doenças Parasitárias/parasitologia , Plasmodium/fisiologia , Schistosoma/fisiologia , Trypanosoma/fisiologia
6.
Front Immunol ; 12: 635513, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33953712

RESUMO

Schistosome infection is a major cause of global morbidity, particularly in sub-Saharan Africa. However, there is no effective vaccine for this major neglected tropical disease, and re-infection routinely occurs after chemotherapeutic treatment. Following invasion through the skin, larval schistosomula enter the circulatory system and migrate through the lung before maturing to adulthood in the mesenteric or urogenital vasculature. Eggs released from adult worms can become trapped in various tissues, with resultant inflammatory responses leading to hepato-splenic, intestinal, or urogenital disease - processes that have been extensively studied in recent years. In contrast, although lung pathology can occur in both the acute and chronic phases of schistosomiasis, the mechanisms underlying pulmonary disease are particularly poorly understood. In chronic infection, egg-mediated fibrosis and vascular destruction can lead to the formation of portosystemic shunts through which eggs can embolise to the lungs, where they can trigger granulomatous disease. Acute schistosomiasis, or Katayama syndrome, which is primarily evident in non-endemic individuals, occurs during pulmonary larval migration, maturation, and initial egg-production, often involving fever and a cough with an accompanying immune cell infiltrate into the lung. Importantly, lung migrating larvae are not just a cause of inflammation and pathology but are a key target for future vaccine design. However, vaccine efforts are hindered by a limited understanding of what constitutes a protective immune response to larvae. In this review, we explore the current understanding of pulmonary immune responses and inflammatory pathology in schistosomiasis, highlighting important unanswered questions and areas for future research.


Assuntos
Pneumopatias Parasitárias/parasitologia , Pulmão/parasitologia , Schistosoma/patogenicidade , Esquistossomose/parasitologia , Animais , Modelos Animais de Doenças , Interações Hospedeiro-Parasita , Humanos , Evasão da Resposta Imune , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pneumopatias Parasitárias/imunologia , Pneumopatias Parasitárias/prevenção & controle , Camundongos , Vacinas Protozoárias/uso terapêutico , Schistosoma/efeitos dos fármacos , Schistosoma/imunologia , Esquistossomose/imunologia , Esquistossomose/prevenção & controle , Esquistossomicidas/uso terapêutico
7.
PLoS Pathog ; 17(5): e1009555, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34015063

RESUMO

Although a growing number of studies suggest interactions between Schistosoma parasites and viral infections, the effects of schistosome infections on the host response to viruses have not been evaluated comprehensively. In this systematic review, we investigated how schistosomes impact incidence, virulence, and prevention of viral infections in humans and animals. We also evaluated immune effects of schistosomes in those coinfected with viruses. We screened 4,730 studies and included 103. Schistosomes may increase susceptibility to some viruses, including HIV and Kaposi's sarcoma-associated herpesvirus, and virulence of hepatitis B and C viruses. In contrast, schistosome infection may be protective in chronic HIV, Human T-cell Lymphotropic Virus-Type 1, and respiratory viruses, though further research is needed. Schistosome infections were consistently reported to impair immune responses to hepatitis B and possibly measles vaccines. Understanding the interplay between schistosomes and viruses has ramifications for anti-viral vaccination strategies and global control of viral infections.


Assuntos
Antivirais/farmacologia , Coinfecção/prevenção & controle , Imunidade/imunologia , Schistosoma/imunologia , Esquistossomose/complicações , Viroses/prevenção & controle , Vírus/imunologia , Animais , Coinfecção/etiologia , Coinfecção/patologia , Humanos , Esquistossomose/parasitologia , Viroses/etiologia , Viroses/patologia
8.
Acta Trop ; 219: 105893, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33872586

RESUMO

Over 90% of schistosomiasis infections occur in sub-Saharan Africa. A rapid ICT test would be a cheap and easy tool that could be used also in the field. We preliminarily evaluated the performance of a new Schistosoma black-latex based IgG-IgM ICT (Black-ICT) on serum samples. The results indicate a high sensitivity (98.0%) but the specificity depends on the application of a cut-off value that can discriminate between positive and negative samples. Considering a possible direct application of this test on blood from finger prick, the results are promising, providied that a signal intensity scale is developed, guiding the result interpretation.


Assuntos
Testes Imunológicos/métodos , Schistosoma/isolamento & purificação , Animais , Anticorpos Anti-Helmínticos/sangue , Humanos , Imunoglobulina G/sangue , Schistosoma/imunologia , Sensibilidade e Especificidade
9.
Front Immunol ; 12: 613468, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33659002

RESUMO

Schistosomiasis remains the fourth most prevalent parasitic disease affecting over 200 million people worldwide. Control efforts have focussed on the disruption of the life cycle targeting the parasite, vector and human host. Parasite burdens are highly skewed, and the majority of eggs are shed into the environment by a minority of the infected population. Most morbidity results from hepatic fibrosis leading to portal hypertension and is not well-correlated with worm burden. Genetics as well as environmental factors may play a role in these skewed distributions and understanding the genetic risk factors for intensity of infection and morbidity may help improve control measures. In this review, we focus on how genetic factors may influence parasite load, hepatic fibrosis and portal hypertension. We found 28 studies on the genetics of human infection and 20 studies on the genetics of pathology in humans. S. mansoni and S. haematobium infection intensity have been showed to be controlled by a major quantitative trait locus SM1, on chromosome 5q31-q33 containing several genes involved in the Th2 immune response, and three other loci of smaller effect on chromosomes 1, 6, and 7. The most common pathology associated with schistosomiasis is hepatic and portal vein fibroses and the SM2 quantitative trait locus on chromosome six has been linked to intensity of fibrosis. Although there has been an emphasis on Th2 cytokines in candidate gene studies, we found that four of the five QTL regions contain Th17 pathway genes that have been included in schistosomiasis studies: IL17B and IL12B in SM1, IL17A and IL17F in 6p21-q2, IL6R in 1p21-q23 and IL22RA2 in SM2. The Th17 pathway is known to be involved in response to schistosome infection and hepatic fibrosis but variants in this pathway have not been tested for any effect on the regulation of these phenotypes. These should be priorities for future studies.


Assuntos
Variação Genética , Genoma Helmíntico , Hepatopatias/etiologia , Schistosoma/genética , Esquistossomose/parasitologia , Alelos , Animais , Mapeamento Cromossômico , Biologia Computacional/métodos , Gerenciamento Clínico , Genes de Helmintos , Ligação Genética , Estudo de Associação Genômica Ampla , Humanos , Hipertensão Portal/diagnóstico , Hipertensão Portal/etiologia , Hepatopatias/diagnóstico , Anotação de Sequência Molecular , Carga Parasitária , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Schistosoma/imunologia , Esquistossomose/complicações , Esquistossomose/diagnóstico , Índice de Gravidade de Doença
10.
Parasit Vectors ; 14(1): 149, 2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750443

RESUMO

BACKGROUND: An accurate test for the diagnosis and post-treatment follow-up of patients with schistosomiasis is needed. We assessed the performance of different laboratory parameters, including the up-converting reporter particle technology lateral flow assay to detect circulating anodic antigen (UCP-LF CAA), for the post-treatment follow-up of schistosomiasis in migrants attending a dedicated outpatient clinic in a non-endemic country. METHODS: Routine anti-Schistosoma serology results and eosinophil counts were obtained of patients with positive urine/stool microscopy and/or PCR (confirmed cases) or only positive serology (possible cases), and at least one follow-up visit at 6 (T6) or 12 (T12) months after praziquantel treatment. All sera samples were tested with the UCP-LF CAA assay. RESULTS: Forty-eight patients were included, 23 confirmed and 25 possible cases. The percentage seropositivity and median antibody titers did not change significantly during follow-up. UCP-LF CAA was positive in 86.9% of confirmed and 20% of possible cases. The percentage positivity and median CAA levels decreased significantly post-treatment, with only two patients having positive CAA levels at T12. CONCLUSIONS: The UCP-LF CAA assay proved useful for the diagnosis of active infection with Schistosoma spp. and highly valuable for post-treatment monitoring in migrants, encouraging the development of a commercial test.


Assuntos
Antígenos de Helmintos/sangue , Eosinófilos/imunologia , Glicoproteínas/sangue , Proteínas de Helminto/sangue , Testes Imunológicos/normas , Microscopia/normas , Schistosoma/imunologia , Esquistossomose/diagnóstico , Migrantes/estatística & dados numéricos , Adolescente , Adulto , Animais , Antígenos de Helmintos/imunologia , Feminino , Glicoproteínas/imunologia , Proteínas de Helminto/imunologia , Humanos , Testes Imunológicos/métodos , Contagem de Leucócitos/métodos , Contagem de Leucócitos/normas , Masculino , Microscopia/métodos , Pessoa de Meia-Idade , Estudos Prospectivos , Schistosoma/classificação , Schistosoma/genética , Esquistossomose/sangue , Esquistossomose/urina , Sensibilidade e Especificidade , Adulto Jovem
11.
Front Immunol ; 12: 605235, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33692784

RESUMO

Schistosomiasis is a parasitic disease that affects about 166 million people around the world. It is estimated that 5%-10% of individuals with schistosomiasis develop severe forms of the disease, which are characterized by pulmonary hypertension, ascites, periportal fibrosis, and other significant complications. The chronic phase of the disease is associated with a Th2 type immune response, but evidence also suggests there are roles for Th1 and Th17 in the development of severe disease. The aim of this study was to evaluate the CD4+ T lymphocyte profile of patients with different degrees of periportal fibrosis secondary to schistosomiasis. These individuals had been treated for schistosomiasis, but since they live in a S. mansoni endemic area, they are at risk of reinfection. They were evaluated in relation to the degree of periportal fibrosis and classified into three groups: without fibrosis or with incipient fibrosis (WF/IFNE), n=12, possible periportal fibrosis/periportal fibrosis, n=13, and advanced periportal fibrosis/advanced periportal fibrosis with portal hypertension, n=4. We observed in the group without fibrosis a balance between the low expression of Th2 cytokines and high expression of T reg cells. As has already been described in the literature, we found an increase of the Th2 cytokines IL-4, IL-5, and IL-13 in the group with periportal fibrosis. In addition, this group showed higher expression of IL-17 and IL-10 but lower IL-10/IL-13 ratio than patients in the WF/IFNE group. Cells from individuals who present any level of fibrosis expressed more TGF-ß compared to the WF/IFNE group and a positive correlation with left lobe enlargement and portal vein wall thickness. There was a negative correlation between IL-17 and the thickness of the portal vein wall, but more studies are necessary in order to explore the possible protective role of this cytokine. Despite the fibrosis group having presented a higher expression of pro-fibrotic molecules compared to WF/IFNE patients, it seems there is a regulation through IL-10 and T reg cells that is able to maintain the low morbidity of this group.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Fibrose/etiologia , Fibrose/metabolismo , Schistosoma/imunologia , Esquistossomose/complicações , Esquistossomose/parasitologia , Animais , Biomarcadores , Citocinas/metabolismo , Suscetibilidade a Doenças , Feminino , Fibrose/patologia , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
12.
Front Immunol ; 12: 599014, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33746946

RESUMO

Schistosomes infect about 250 million people globally causing the devastating and persistent disease of schistosomiasis. These blood flukes have a complicated life cycle involving alternating infection of freshwater snail intermediate and definitive mammalian hosts. To survive and flourish in these diverse environments, schistosomes transition through a number of distinct life-cycle stages as a result of which they change their body plan in order to quickly adapt to each new environment. Current research suggests that stem cells, present in adults and larvae, are key in aiding schistosomes to facilitate these changes. Given the recent advances in our understanding of schistosome stem cell biology, we review the key roles that two major classes of cells play in the different life cycle stages during intramolluscan and intramammalian development; these include the germinal cells of sporocysts involved in asexual reproduction in molluscan hosts and the neoblasts of adult worms involved in sexual reproduction in human and other mammalian hosts. These studies shed considerable new light in revealing the stem cell heterogeneity driving the propagation of the schistosome life cycle. We also consider the possibility and value of establishing stem cell lines in schistosomes to advance schistosomiasis research. The availability of such self-renewable resources will provide new platforms to study stem cell behavior and regulation, and to address fundamental aspects of schistosome biology, reproductive development and survival. In turn, such studies will create new avenues to unravel individual gene function and to optimize genome-editing processes in blood flukes, which may lead to the design of novel intervention strategies for schistosomiasis.


Assuntos
Schistosoma , Esquistossomose/imunologia , Células-Tronco , Animais , Pesquisa Biomédica , Schistosoma/citologia , Schistosoma/imunologia , Células-Tronco/citologia , Células-Tronco/imunologia
13.
Front Immunol ; 12: 635985, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33746974

RESUMO

Despite mass drug administration programmes with praziquantel, the prevalence of schistosomiasis remains high. A vaccine is urgently needed to control transmission of this debilitating disease. As some promising schistosomiasis vaccine candidates are moving through pre-clinical and clinical testing, we review the immunological challenges that these vaccine candidates may encounter in transitioning through the clinical trial phases in endemic settings. Prior exposure of the target population to schistosomes and other infections may impact vaccine response and efficacy and therefore requires considerable attention. Schistosomes are known for their potential to induce T-reg/IL-10 mediated immune suppression in populations which are chronically infected. Moreover, endemicity of schistosomiasis is focal whereby target and trial populations may exhibit several degrees of prior exposure as well as in utero exposure which may increase heterogeneity of vaccine responses. The age dependent distribution of exposure and development of acquired immunity, and general differences in the baseline immunological profile, adds to the complexity of selecting suitable trial populations. Similarly, prior or concurrent infections with other parasitic helminths, viral and bacterial infections, may alter immunological responses. Consequently, treatment of co-infections may benefit the immunogenicity of vaccines and may be considered despite logistical challenges. On the other hand, viral infections leave a life-long immunological imprint on the human host. Screening for serostatus may be needed to facilitate interpretation of vaccine responses. Co-delivery of schistosome vaccines with PZQ is attractive from a perspective of implementation but may complicate the immunogenicity of schistosomiasis vaccines. Several studies have reported PZQ treatment to induce both transient and long-term immuno-modulatory effects as a result of tegument destruction, worm killing and subsequent exposure of worm antigens to the host immune system. These in turn may augment or antagonize vaccine immunogenicity. Understanding the complex immunological interactions between vaccine, co-infections or prior exposure is essential in early stages of clinical development to facilitate phase 3 clinical trial design and implementation policies. Besides well-designed studies in different target populations using schistosome candidate vaccines or other vaccines as models, controlled human infections could also help identify markers of immune protection in populations with different disease and immunological backgrounds.


Assuntos
Desenvolvimento de Medicamentos , Doenças Endêmicas/prevenção & controle , Vacinas Protozoárias/uso terapêutico , Schistosoma/imunologia , Esquistossomose/prevenção & controle , Animais , Coinfecção , Desenho de Fármacos , Interações Hospedeiro-Parasita , Humanos , Imunogenicidade da Vacina , Praziquantel/uso terapêutico , Vacinas Protozoárias/efeitos adversos , Vacinas Protozoárias/imunologia , Schistosoma/patogenicidade , Esquistossomose/epidemiologia , Esquistossomose/imunologia , Esquistossomose/transmissão , Esquistossomicidas/uso terapêutico
14.
J Microbiol Immunol Infect ; 54(3): 501-513, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32033858

RESUMO

BACKGROUND: The regulation of the balance between inflammatory and anti-inflammatory events during the treatment of pulmonary infection is very important. Soluble Schistosoma egg antigens (SEA) can effectively inhibit the expression of cytokines during hepatic acute inflammation. However, the mechanisms by which these proteins suppress the inflammatory responses in lung cells remain unclear. The purpose of this study was to investigate the ability of SEA to inhibit pulmonary inflammation. METHODS: The effects of SEA were investigated in LPS-treated lung IMR-90 cells. The involvement of the JAK/STAT-1 signaling pathway in these effects was evaluated by employing CBA assays, quantitative polymerase chain reaction, and western blotting experiments. RESULTS: Pretreatment of IMR-90 cells with appropriate concentrations of SEA protected cells against the cytotoxic effects of LPS-induced inflammation in a time-dependent manner. SEA pretreatment significantly attenuated the LPS-induced activation of the JAK/STAT1 signaling pathway, including the upregulation of JAK1/2 and STAT1, as well as the production of inflammatory cytokines. The level of phosphorylated STAT1 gradually declined in response to increasing concentrations of SEA. Based on these findings, we hypothesize that SEA-induced anti-inflammatory effects initiate with the downregulation of the IFN-γ-JAK-STAT1 signaling pathway, resulting in the attenuation of LPS-induced inflammation in IMR-90 cells. CONCLUSION: Our study is the first to demonstrate the anti-inflammatory activity of SEA in an in vitro model of pulmonary inflammation, involving the modulation of JAK/STAT1 signaling. We propose SEA as potential therapeutic or preventive agents for the selective suppression of STAT1 and the control of inflammatory response in lung IMR-90 cells.


Assuntos
Antígenos de Helmintos/farmacologia , Fibroblastos/efeitos dos fármacos , Inflamação/prevenção & controle , Janus Quinase 1/metabolismo , Lipopolissacarídeos/farmacologia , Óvulo/química , Fator de Transcrição STAT1/metabolismo , Schistosoma/imunologia , Transdução de Sinais , Animais , Linhagem Celular , Humanos , Janus Quinase 1/imunologia , Lipopolissacarídeos/metabolismo , Fator de Transcrição STAT1/imunologia , Schistosoma/química
15.
Curr Top Med Chem ; 21(3): 193-204, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32972342

RESUMO

Schistosomiasis is a neglected tropical disease. It is related to long-lasting granulomatous fibrosis and inflammation of target organs, and current sub-optimal pharmacological treatment creates global public health concerns. Intravascular worms and eggs release antigens and extracellular vesicles that target host endothelial cells, modulate the immune system, and stimulate the release of damageassociated molecular patterns (DAMPs). ATP, one of the most studied DAMPs, triggers a cascade of autocrine and paracrine actions through purinergic P2X and P2Y receptors, which are shaped by ectonucleotidases (CD39). Both P2 receptor families, and in particular P2Y1, P2Y2, P2Y12, and P2X7 receptors, have been attracting increasing interest in several inflammatory diseases and drug development. Current data obtained from the murine model unveiled a CD39-ADP-P2Y1/P2Y12 receptors signaling pathway linked to the liver and mesenteric exacerbations of schistosomal inflammation. Therefore, we proposed that members of this purinergic signaling could be putative pharmacological targets to reduce schistosomal morbidity.


Assuntos
Anti-Helmínticos/farmacologia , Receptores Purinérgicos/imunologia , Esquistossomose/tratamento farmacológico , Animais , Humanos , Inflamação/tratamento farmacológico , Inflamação/imunologia , Schistosoma/efeitos dos fármacos , Schistosoma/imunologia , Esquistossomose/imunologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia
16.
Immunology ; 162(2): 123-134, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32614982

RESUMO

Macrophages are fundamental to sustain physiological equilibrium and to regulate the pathogenesis of parasitic and metabolic processes. The functional heterogeneity and immune responses of macrophages are shaped by cellular metabolism in response to the host's intrinsic factors, environmental cues and other stimuli during disease. Parasite infections induce a complex cascade of cytokines and metabolites that profoundly remodel the metabolic status of macrophages. In particular, helminths polarize macrophages to an M2 state and induce a metabolic shift towards reliance on oxidative phosphorylation, lipid oxidation and amino acid metabolism. Accumulating data indicate that helminth-induced activation and metabolic reprogramming of macrophages underlie improvement in overall whole-body metabolism, denoted by improved insulin sensitivity, body mass in response to high-fat diet and atherogenic index in mammals. This review aims to highlight the metabolic changes that occur in human and murine-derived macrophages in response to helminth infections and helminth products, with particular interest in schistosomiasis and soil-transmitted helminths.


Assuntos
Helmintíase/imunologia , Helmintos/imunologia , Intestinos/imunologia , Intestinos/parasitologia , Macrófagos/imunologia , Schistosoma/imunologia , Esquistossomose/imunologia , Animais , Citocinas/imunologia , Humanos , Macrófagos/parasitologia
17.
Curr Drug Discov Technol ; 18(4): 473-484, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32767945

RESUMO

Schistosome infection is regarded as one of the most important and neglected tropical diseases associated with poor sanitation. Like other living organisms, schistosomes employ multiple biological processes, of which some are regulated by a post-translational modification called Adenosine Diphosphate-ribosylation (ADP-ribosylation), catalyzed by ADP-ribosyltransferases. ADP-ribosylation is the addition of ADP-ribose moieties from Nicotinamide Adenine Dinucleotide (NAD+) to various targets, which include proteins and nucleotides. It is crucial in biological processes such as DNA repair, apoptosis, carbohydrate metabolism and catabolism. In the absence of a vaccine against schistosomiasis, this becomes a promising pathway in the identification of drug targets against various forms of this infection. The tegument of the worm is an encouraging immunogenic target for anti-schistosomal vaccine development. Vaccinology, molecular modeling and target-based drug discovery strategies have been used for years in drug discovery and for vaccine development. In this paper, we outline ADP-ribosylation and other different approaches to drug discovery and vaccine development against schistosomiasis.


Assuntos
ADP-Ribosilação/imunologia , Anti-Helmínticos/farmacologia , Doenças Negligenciadas/terapia , Schistosoma/imunologia , Esquistossomose/terapia , ADP-Ribosilação/efeitos dos fármacos , Animais , Anti-Helmínticos/uso terapêutico , Antígenos de Helmintos/imunologia , Descoberta de Drogas/métodos , Humanos , Doenças Negligenciadas/imunologia , Doenças Negligenciadas/parasitologia , Schistosoma/efeitos dos fármacos , Esquistossomose/imunologia , Esquistossomose/parasitologia , Desenvolvimento de Vacinas/métodos
18.
Front Immunol ; 11: 609994, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33281832

RESUMO

Blood flukes of the genus Schistosoma are covered by a protective heptalaminated, double lipid bilayer surface membrane. Large amounts of sphingomyelin (SM) in the outer leaflet form with surrounding water molecules a tight hydrogen bond barrier, which allows entry of nutrients and prevents access of host immune effectors. Excessive hydrolysis of SM to phosphoryl choline and ceramide via activation of the parasite tegument-associated neutral sphingomyelinase (nSMase) with the polyunsaturated fatty acid, arachidonic acid (ARA) leads to parasite death, via allowing exposure of apical membrane antigens to antibody-dependent cell-mediated cytotoxicity (ADCC), and accumulation of the pro-apoptotic ceramide. Surface membrane nSMase represents, thus, a worm Achilles heel, and ARA a valid schistosomicide. Several experiments conducted in vitro using larval, juvenile, and adult Schistosoma mansoni and Schistosoma haematobium documented ARA schistosomicidal potential. Arachidonic acid schistosomicidal action was shown to be safe and efficacious in mice and hamsters infected with S. mansoni and S. haematobium, respectively, and in children with light S. mansoni infection. A combination of praziquantel and ARA led to outstanding cure rates in children with heavy S. mansoni infection. Additionally, ample evidence was obtained for the powerful ARA ovocidal potential in vivo and in vitro against S. mansoni and S. haematobium liver and intestine eggs. Studies documented ARA as an endogenous schistosomicide in the final mammalian and intermediate snail hosts, and in mice and hamsters, immunized with the cysteine peptidase-based vaccine. These findings together support our advocating the nutrient ARA as the safe and efficacious schistosomicide of the future.


Assuntos
Antígenos de Helmintos/administração & dosagem , Ácido Araquidônico/uso terapêutico , Cisteína Proteases/administração & dosagem , Schistosoma/efeitos dos fármacos , Esquistossomose/tratamento farmacológico , Esquistossomicidas/uso terapêutico , Vacinas/administração & dosagem , Animais , Antígenos de Helmintos/imunologia , Ácido Araquidônico/efeitos adversos , Ácido Araquidônico/metabolismo , Cisteína Proteases/imunologia , Modelos Animais de Doenças , Interações Hospedeiro-Parasita , Humanos , Contagem de Ovos de Parasitas , Schistosoma/imunologia , Schistosoma/patogenicidade , Esquistossomose/imunologia , Esquistossomose/metabolismo , Esquistossomose/parasitologia , Esquistossomicidas/efeitos adversos , Resultado do Tratamento , Vacinação , Vacinas/imunologia
19.
BMJ Case Rep ; 13(10)2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33127722

RESUMO

A 62-year-old Asian man presented with a 3-month history of right iliac fossa pain which had progressively worsened over the last 3 weeks. All blood parameters were found to be unremarkable except for mildly elevated erythrocyte sedimentation rate. CT imaging demonstrated thickening of the ascending colon and caecum. Colonoscopic biopsies showed submucosal granulomas with features suggestive of schistosomiasis and parasite serology was positive for Schistosoma antibodies. He was treated with praziquantel and showed subsequent symptomatic and radiological improvement. However, he represented nearly 2 years later and underwent a right hemicolectomy for small bowel obstruction. The resected bowel showed an inflammatory caecal mass and a terminal ileal adenocarcinoma.


Assuntos
Dor Abdominal/etiologia , Doenças do Ceco/complicações , Ceco/patologia , Obstrução Intestinal/etiologia , Esquistossomose/complicações , Dor Abdominal/diagnóstico , Animais , Anticorpos Anti-Helmínticos/análise , Biópsia , Doenças do Ceco/diagnóstico , Doenças do Ceco/parasitologia , Ceco/parasitologia , Diagnóstico Diferencial , Humanos , Obstrução Intestinal/diagnóstico , Masculino , Pessoa de Meia-Idade , Schistosoma/imunologia , Esquistossomose/diagnóstico , Esquistossomose/parasitologia , Tomografia Computadorizada por Raios X , Reino Unido
20.
Microbes Infect ; 22(10): 534-539, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841730

RESUMO

Parasites of the genus Schistosoma are organisms capable of living for decades within the definitive host. They interfere with the immune response by interacting with host's receptors. In this review, we discuss from the first reports to the most recent discoveries regarding the ability of Schistosoma antigens in triggering intracellular receptors and inducing inflammasome activation.


Assuntos
Antígenos de Helmintos/metabolismo , Inflamassomos/metabolismo , Schistosoma/metabolismo , Animais , Células Dendríticas/metabolismo , Células Estreladas do Fígado/metabolismo , Interleucina-1beta/metabolismo , Macrófagos/metabolismo , Proteínas NLR/metabolismo , Óvulo , Piroptose , Schistosoma/imunologia , Esquistossomose/metabolismo , Esquistossomose/parasitologia
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