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 JovemRESUMO
Freshwater snails of the genus Biomphalaria serve as intermediate hosts for the digenetic trematode Schistosoma mansoni, the etiological agent for the most widespread form of intestinal schistosomiasis. As neuropeptide signaling in host snails can be altered by trematode infection, a neural transcriptomics approach was undertaken to identify peptide precursors in Biomphalaria glabrata, the major intermediate host for S. mansoni in the Western Hemisphere. Three transcripts that encode peptides belonging to the FMRF-NH2 -related peptide (FaRP) family were identified in B. glabrata. One transcript encoded a precursor polypeptide (Bgl-FaRP1; 292 amino acids) that included eight copies of the tetrapeptide FMRF-NH2 and single copies of FIRF-NH2 , FLRF-NH2 , and pQFYRI-NH2 . The second transcript encoded a precursor (Bgl-FaRP2; 347 amino acids) that comprised 14 copies of the heptapeptide GDPFLRF-NH2 and 1 copy of SKPYMRF-NH2 . The precursor encoded by the third transcript (Bgl-FaRP3; 287 amino acids) recapitulated Bgl-FaRP2 but lacked the full SKPYMRF-NH2 peptide. The three precursors shared a common signal peptide, suggesting a genomic organization described previously in gastropods. Immunohistochemical studies were performed on the nervous systems of B. glabrata and B. alexandrina, a major intermediate host for S. mansoni in Egypt. FMRF-NH2 -like immunoreactive (FMRF-NH2 -li) neurons were located in regions of the central nervous system associated with reproduction, feeding, and cardiorespiration. Antisera raised against non-FMRF-NH2 peptides present in the tetrapeptide and heptapeptide precursors labeled independent subsets of the FMRF-NH2 -li neurons. This study supports the participation of FMRF-NH2 -related neuropeptides in the regulation of vital physiological and behavioral systems that are altered by parasitism in Biomphalaria.
Assuntos
FMRFamida/genética , Neuropeptídeos/genética , Esquistossomose mansoni/genética , Transcriptoma/genética , Sequência de Aminoácidos , Animais , Biomphalaria , FMRFamida/análise , FMRFamida/metabolismo , Neuropeptídeos/análise , Neuropeptídeos/metabolismo , Imagem Óptica/métodos , Schistosoma mansoni/genética , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/metabolismoRESUMO
Freshwater snails of the genus Biomphalaria serve as obligatory hosts for the digenetic trematode Schistosoma mansoni, the causative agent for the most widespread form of intestinal schistosomiasis. Within Biomphalaria, S. mansoni larvae multiply and transform into the cercariae form that can infect humans. Trematode development and proliferation is thought to be facilitated by modifications of host behavior and physiological processes, including a reduction of reproduction known as "parasitic castration." As neuropeptides participate in the control of reproduction across phylogeny, a neural transcriptomics approach was undertaken to identify peptides that could regulate Biomphalaria reproductive physiology. The present study identified a transcript in Biomphalaria alexandrina that encodes a peptide belonging to the gonadotropin-releasing hormone (GnRH) superfamily. The precursor and the predicted mature peptide, pQIHFTPDWGNN-NH2 (designated Biom-GnRH), share features with peptides identified in other molluscan species, including panpulmonates, opisthobranchs, and cephalopods. An antibody generated against Biom-GnRH labeled neurons in the cerebral, pedal, and visceral ganglia of Biomphalaria glabrata. GnRH-like immunoreactive fiber systems projected to all central ganglia. In the periphery, immunoreactive material was detected in the ovotestis, oviduct, albumen gland, and nidamental gland. As these structures serve crucial roles in the production, transport, nourishment, and encapsulation of eggs, disruption of the GnRH system of Biomphalaria could contribute to reduced reproductive activity in infected snails.
Assuntos
Biomphalaria/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Interações Hospedeiro-Parasita/fisiologia , Schistosoma mansoni/metabolismo , Esquistossomose mansoni/metabolismo , Sequência de Aminoácidos , Animais , Biomphalaria/química , Biomphalaria/genética , Hormônio Liberador de Gonadotropina/análise , Hormônio Liberador de Gonadotropina/genética , Neuropeptídeos , Schistosoma mansoni/genética , Esquistossomose mansoni/genéticaRESUMO
BACKGROUND: Schistosoma mansoni schistosomiasis (SM) remains a public health problem in Brazil. Renal involvement is classically manifested as a glomerulopathy, most often membranoproliferative glomerulonephritis or focal and segmental glomerulosclerosis. We report a case of collapsing glomerulopathy (CG) associated with SM and high-risk APOL1 genotype (HRG). CASE REPORT: A 35-year-old male was admitted for hypertension and an eight-month history of lower-limb edema, foamy urine, and increased abdominal girth. He had a recent diagnosis of hepatosplenic SM, treated with praziquantel, without clinical improvement. Laboratory tests revealed serum creatinine 1.89mg/dL, blood urea nitrogen (BUN) 24mg/dL, albumin 1.9g/dL, cholesterol 531mg/dL, low-density lipoprotein 426mg/dL, platelets 115000/mm3, normal C3/C4, antinuclear antibody (ANA), rheumatoid factor (RF), and antineutrophil cytoplasmic antibodies (ANCA), negative serologies for hepatitis C virus (HCV) and human immunodeficiency virus (HIV), HBsAg negative and AntiHBc IgG positive, no hematuria or leukocyturia, 24 hour proteinuria 6.56g and negative serum and urinary immunofixation. Kidney biopsy established the diagnosis of CG. A treatment with prednisone was started without therapeutic response, progressing to end-stage kidney disease 19 months later. Molecular genetics investigation revealed an HRG. CONCLUSIONS: This is the first report of CG associated with SM in the setting of an HRG. This case highlights the two-hit model as a mechanism for CG pathogenesis, where the high-risk APOL1 genotype exerts a susceptibility role and SM infection serves as a trigger to CG.
Assuntos
Apolipoproteína L1/genética , Falência Renal Crônica/complicações , Glomérulos Renais/patologia , Esquistossomose mansoni/complicações , Esquistossomose mansoni/patologia , Adulto , Animais , Brasil , Humanos , Masculino , Schistosoma mansoni , Esquistossomose mansoni/genéticaRESUMO
BACKGROUND: Biomphalaria glabrata snails are widely distributed in schistosomiasis endemic areas like America and Caribe, displaying high susceptibility to infection by Schistosoma mansoni. After the availability of B. glabrata genome and transcriptome data, studies focusing on genetic markers and small non-coding RNAs have become more relevant. The small RNAs have been considered important through their ability to finely regulate the gene expression in several organisms, thus controlling the functions like cell growth, metabolism, and susceptibility/resistance to infection. OBJECTIVE: The present study aims on identification and characterisation of the repertoire of small non-coding RNAs in B. glabrata (Bgl-small RNAs). METHODS: By using small RNA sequencing, bioinformatics tools and quantitative reverse transcription polymerase chain reaction (RT-qPCR), we identified, characterised, and validated the presence of small RNAs in B. glabrata. FINDINGS: 89 mature miRNAs were identified and five of them were classified as Mollusk-specific. When compared to model organisms, sequences of B. glabrata miRNAs showed a high degree of conservation. In addition, several target genes were predicted for all the mature miRNAs identified. Furthermore, piRNAs were identified in the genome of B. glabrata for the first time. The B. glabrata piRNAs showed strong conservation of uridine as first nucleotide at 5' end, besides adenine at 10th position. Our results showed that B. glabrata has diverse repertoire of circulating ncRNAs, several which might be involved in mollusk susceptibility to infection, due to their potential roles in the regulation of S. mansoni development. MAIN CONCLUSIONS: Further studies are necessary in order to confirm the role of the Bgl-small RNAs in the parasite/host relationship thus opening new perspectives on interference of small RNAs in the organism development and susceptibility to infection.
Assuntos
Biomphalaria/genética , Biomphalaria/parasitologia , MicroRNAs/genética , Schistosoma mansoni/fisiologia , Esquistossomose mansoni/genética , Esquistossomose mansoni/fisiopatologia , Animais , Predisposição Genética para Doença/genética , Sequenciamento de Nucleotídeos em Larga Escala , Interações Hospedeiro-Parasita , RNA Interferente Pequeno , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Micro Exon Gene (MEG) proteins are thought to play major roles in the infection and survival of parasitic Schistosoma mansoni worms in host organisms. Here, the physical chemical properties of two small MEG proteins found in the genome of S. mansoni, named MEG-24 and MEG-27, were examined by a combination of biophysical techniques such as differential scanning calorimetry, tensiometry, circular dichroism, fluorescence, and electron spin resonance spectroscopies. The proteins are surface active and structurally arranged as cationic amphipathic α-helices that can associate with lipid membranes and cause their disruption. Upon adsorption to lipid membranes, MEG-27 strongly affects the fluidity of erythrocyte ghost membranes, whereas MEG-24 forms pores in erythrocytes without modifying the ghost membrane fluidity. Whole-mount in situ hybridization experiments indicates that MEG-27 and MEG-24 transcripts are located in the parasite esophagus and subtegumental cells, respectively, suggesting a relevant role of these proteins in the host-parasite interface. Taken together, these characteristics lead us to propose that these MEG proteins may interact with host cell membranes and potentially modulate the immune process using a similar mechanism as that described for α-helical membrane-active peptides.
Assuntos
Éxons/genética , Membranas/química , Schistosoma mansoni/genética , Sequência de Aminoácidos , Animais , Varredura Diferencial de Calorimetria/métodos , Dicroísmo Circular/métodos , Peptídeos/química , Conformação Proteica em alfa-Hélice , Schistosoma mansoni/metabolismo , Esquistossomose mansoni/genética , Esquistossomose mansoni/metabolismoRESUMO
The radiation-attenuated cercarial vaccine remains the gold standard for the induction of protective immunity against Schistosoma mansoni. Furthermore, the protection can be passively transferred to naïve recipient mice from multiply vaccinated donors, especially IFNgR KO mice. We have used such sera versus day 28 infection serum, to screen peptide arrays and identify likely epitopes that mediate the protection. The arrays encompassed 55 secreted or exposed proteins from the alimentary tract and tegument, the principal interfaces with the host bloodstream. The proteins were printed onto glass slides as overlapping 15mer peptides, reacted with primary and secondary antibodies, and reactive regions detected using an Agilent array scanner. Pep Slide Analyzer software provided a numerical value above background for each peptide from which an aggregate score could be derived for a putative epitope. The reactive regions of 26 proteins were mapped onto crystal structures using the CCP4 molecular graphics, to aid selection of peptides with the greatest accessibility and reactivity, prioritizing vaccine over infection serum. A further eight MEG proteins were mapped to regions conserved between family members. The result is a list of priority peptides from 44 proteins for further investigation in multiepitope vaccine constructs and as targets of monoclonal antibodies.
Assuntos
Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/imunologia , Mapeamento de Epitopos , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Animais , Antígenos de Helmintos/genética , Camundongos , Camundongos Knockout , Schistosoma mansoni/genética , Esquistossomose mansoni/genética , Esquistossomose mansoni/prevenção & controle , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologiaRESUMO
BACKGROUND Biomphalaria glabrata snails are widely distributed in schistosomiasis endemic areas like America and Caribe, displaying high susceptibility to infection by Schistosoma mansoni. After the availability of B. glabrata genome and transcriptome data, studies focusing on genetic markers and small non-coding RNAs have become more relevant. The small RNAs have been considered important through their ability to finely regulate the gene expression in several organisms, thus controlling the functions like cell growth, metabolism, and susceptibility/resistance to infection. OBJECTIVE The present study aims on identification and characterisation of the repertoire of small non-coding RNAs in B. glabrata (Bgl-small RNAs). METHODS By using small RNA sequencing, bioinformatics tools and quantitative reverse transcription polymerase chain reaction (RT-qPCR), we identified, characterised, and validated the presence of small RNAs in B. glabrata. FINDINGS 89 mature miRNAs were identified and five of them were classified as Mollusk-specific. When compared to model organisms, sequences of B. glabrata miRNAs showed a high degree of conservation. In addition, several target genes were predicted for all the mature miRNAs identified. Furthermore, piRNAs were identified in the genome of B. glabrata for the first time. The B. glabrata piRNAs showed strong conservation of uridine as first nucleotide at 5' end, besides adenine at 10th position. Our results showed that B. glabrata has diverse repertoire of circulating ncRNAs, several which might be involved in mollusk susceptibility to infection, due to their potential roles in the regulation of S. mansoni development. MAIN CONCLUSIONS Further studies are necessary in order to confirm the role of the Bgl-small RNAs in the parasite/host relationship thus opening new perspectives on interference of small RNAs in the organism development and susceptibility to infection.
Assuntos
Animais , Schistosoma mansoni/fisiologia , Biomphalaria/genética , Biomphalaria/parasitologia , Esquistossomose mansoni/fisiopatologia , Esquistossomose mansoni/genética , MicroRNAs/genética , Predisposição Genética para Doença/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , RNA Interferente Pequeno , Sequenciamento de Nucleotídeos em Larga Escala , Interações Hospedeiro-ParasitaRESUMO
Sm16 is an immunomodulatory protein that seems to play a key role in the suppression of the cutaneous inflammatory response during Schistosoma mansoni penetration of the skin of definitive hosts. Therefore, Sm16 represents a potential target for protective immune responses induced by vaccination. In this work, we generated the recombinant protein rSm16 and produced polyclonal antibodies against this protein to evaluate its expression during different parasite life-cycle stages and its location on the surface of the parasite. In addition, we analyzed the immune responses elicited by immunization with rSm16 using two different vaccine formulations, as well as its ability to induce protection in Balb/c mice. In order to explore the biological function of Sm16 during the course of experimental infection, RNA interference was also employed. Our results demonstrated that Sm16 is expressed in cercaria and schistosomula and is located in the schistosomula surface. Despite humoral and cellular immune responses triggered by vaccination using rSm16 associated with either Freund's or alum adjuvants, immunized mice presented no reduction in either parasite burden or parasite egg laying. Knockdown of Sm16 gene expression in schistosomula resulted in decreased parasite size in vitro but had no effect on parasite survival or egg production in vivo. Thus, our findings demonstrate that although the vaccine formulations used in this study succeeded in activating immune responses, these failed to promote parasite elimination. Finally, we have shown that Sm16 is not vital for parasite survival in the definitive host and hence may not represent a suitable target for vaccine development.
Assuntos
Proteínas de Helminto/imunologia , Interações Hospedeiro-Parasita/imunologia , Imunomodulação , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Esquistossomose mansoni/parasitologia , Animais , Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/imunologia , Sequência de Bases , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Técnicas de Silenciamento de Genes , Proteínas de Helminto/química , Proteínas de Helminto/genética , Imunização , Camundongos , Proteínas Recombinantes/imunologia , Schistosoma mansoni/crescimento & desenvolvimento , Esquistossomose mansoni/genética , Esquistossomose mansoni/prevenção & controle , Vacinas/imunologiaRESUMO
AIMS: The proinflammatory cytokine tumor necrosis factor-alpha (TNF-α) is an essential component in the host immune response to infection, and it has been reported to be an important mediator in severe periportal fibrosis (PPF). We hypothesized that the (-G308A) polymorphism of the TNF-α gene is associated with the severity of PPF and that these polymorphisms influence TNF-α expression. METHODS: In this cross-sectional study, we genotyped these polymorphisms within the TNF-α gene in 256 Brazilian subjects infected with Schistosoma mansoni, with different patterns of PPF. RESULTS: The genotype (-308) AA was associated with a significant increase in the risk to advanced PPF (OR = 4.60; p = 0.009). In addition, median levels of TNF-α were higher in patients with moderate to advanced PPF, compared with mild fibrosis (20 and 17.3 pg/mL, respectively; p = 0.040). There was no association between average serum levels of TNF-α and (-G308A) TNF-α polymorphism. CONCLUSIONS: Our results suggest the (-308) AA genotype may be a risk factor for severity in advanced PPF, in this Brazilian population, and could potentially be used to predict the severity of advanced PPF in schistosomiasis.