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1.
Iran J Parasitol ; 17(3): 375-384, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36466014

RESUMO

Background: In previous studies, a new Trichinella spiralis serine protease 1.1 (TsSP1.1) was identified in surface proteins of T. spiralis muscle larvae (ML) by proteomics analysis, but its functions in T. spiralis infection are unknown. The aim of this study was to investigate the roles of TsSP1.1 during larval intrusion of gut epithelium. Methods: From January 2019 to March 2021, complete TsSP1.1 cDNA sequence was cloned and expressed in Escherichia coli BL21 at the Department of Parasitology, Medical College of Zhengzhou University, Zhengzhou, China. Expression and location of TsSP1.1 in the parasite were investigated using indirect immunofluorescence assay (IIFA) and Western blotting. The in vitro intestinal epithelium cells (IECs) intrusion assay was used to ascertain the roles of TsSP1.1 during larval intrusion of IECs and gut epithelium. Results: TsSP1.1 was a surface and secretory protein, which was expressed at various T. spiralis stages, and principally localized at cuticle, stichosome and embryos of the nematode. rTsSP1.1 accelerated larval intrusion of IECs, whereas anti-rTsSP1.1 antibodies impeded larval intrusion. The acceleration and inhibtion was dose-dependently related to rTsSP1.1 and anti-TsSP1.1 antibodies. Block of the IIL with anti-rTsSP1.1 serum also impeded larval intrusion of gut mucosa. Conclusion: TsSP1.1 participates in T. spiralis intrusion of gut epithelium.

2.
Parasit Vectors ; 15(1): 475, 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36539832

RESUMO

BACKGROUND: Trichinella spiralis is an important foodborne parasite that presents a severe threat to food safety. The development of an anti-Trichinella vaccine is an important step towards controlling Trichinella infection in food animals and thus ensure meat safety. Trichinella spiralis galectin (Tsgal) is a novel protein that has been identified on the surface of this nematode. Recombinant Tsgal (rTsgal) was found to participate in larval invasion of intestinal epithelium cells (IECs), whereas anti-rTsgal antibodies impeded the invasion. METHODS: The rTsgal/pSIP409- pgsA' plasmid was constructed and transferred into Lactobacillus plantarum strain NC8, following which the in vitro biological properties of rTsgal/NC8 were determined. Five groups of mice were orally immunized three times, with a 2-week interval between immunizations, with recombinant NC8-Tsgal, recombinant NC8-Tsgal + α-lactose, empty NC8, α-lactose only or phosphate-buffered saline (PBS), respectively. The vaccinated mice were infected orally with T. spiralis larvae 2 weeks following the last vaccination. Systemic and intestinal local mucosal immune responses and protection were also assessed, as were pathological changes in murine intestine and skeletal muscle. RESULTS: rTsgal was expressed on the surface of NC8-Tsgal. Oral immunization of mice with rTsgal vaccine induced specific forms of serum immunoglobulin G (IgG), namely IgG1/IgG2a, as well as IgA and gut mucosal secretion IgA (sIgA). The levels of interferon gamma and interleukin-4 secreted by cells of the spleen, mesenteric lymph nodes, Peyer's patches and intestinal lamina propria were significantly elevated at 2-6 weeks after immunization, and continued to rise following challenge. Immunization of mice with the oral rTsgal vaccine produced a significant immune protection against T. spiralis challenge, as demonstrated by a 57.28% reduction in the intestinal adult worm burden and a 53.30% reduction in muscle larval burden, compared to the PBS control group. Immunization with oral rTsgal vaccine also ameliorated intestinal inflammation, as demonstrated by a distinct reduction in the number of gut epithelial goblet cells and mucin 2 expression level in T. spiralis-infected mice. Oral administration of lactose alone also reduced adult worm and larval burdens and relieved partially inflammation of intestine and muscles. CONCLUSIONS: Immunization with oral rTsgal vaccine triggered an obvious gut local mucosal sIgA response and specific systemic Th1/Th2 immune response, as well as an evident protective immunity against T. spiralis challenge. Oral rTsgal vaccine provided a prospective approach for control of T. spiralis infection.


Assuntos
Lactobacillus plantarum , Trichinella spiralis , Triquinelose , Animais , Camundongos , Lactobacillus plantarum/genética , Galectinas , Larva , Lactose , Triquinelose/parasitologia , Vacinação , Imunoglobulina A Secretora , Vacinas Sintéticas/genética , Proteínas Recombinantes/genética , Imunoglobulina A , Camundongos Endogâmicos BALB C
3.
PLoS Negl Trop Dis ; 16(11): e0010929, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36445875

RESUMO

BACKGROUND: Trichinella spiralis is a foodborne parasitic nematode which is a serious risk to meat safety. Development of anti-Trichinella vaccine is needed to control Trichinella infection in food animals. In this study, two novel T. spiralis genes (calreticulin and serine protease 1.1) in combination were used to construct oral DNA vaccines, and their induced protective immunity was evaluated in a murine model. METHODOLOGY/PRINCIPAL FINDINGS: TsCRT+TsSP1.1, TsCRT and TsSP1.1 DNA were transformed into attenuated Salmonella typhimurium ΔcyaSL1344. Oral vaccination of mice with TsCRT+TsSP1.1, TsCRT and TsSP1.1 DNA vaccines elicited a gut local mucosal sIgA response and systemic Th1/Th2 mixed response. Oral vaccination with TsCRT+TsSP1.1 induced obviously higher level of serum specific antibodies, mucosal sIgA and cellular immune response than either of single TsCRT or TsSP1.1 DNA vaccination. Oral vaccination of mice with TsCRT+TsSP1.1 exhibited a 53.4% reduction of enteral adult worms and a 46.05% reduction of muscle larvae, conferred a higher immune protection than either of individual TsCRT (44.28 and 42.46%) or TsSP1.1 DNA vaccine (35.43 and 29.29%) alone. Oral vaccination with TsCRT+TsSP1.1, TsCRT and TsSP1.1 also obviously ameliorated inflammation of intestinal mucosa and skeletal muscles of vaccinated mice after challenge. CONCLUSIONS: TsCRT and TsSP1.1 might be regarded the novel potential targets for anti-Trichinella vaccines. Attenuated Salmonella-delivered DNA vaccine provided a prospective approach to control T. spiralis infection in food animals.


Assuntos
Trichinella spiralis , Triquinelose , Vacinas de DNA , Animais , Camundongos , Calreticulina , Imunoglobulina A Secretora , Camundongos Endogâmicos BALB C , Salmonella typhimurium/genética , Trichinella spiralis/genética , Vacinação , Vacinas Atenuadas/genética , Vacinas de DNA/genética , Triquinelose/imunologia , Triquinelose/prevenção & controle
4.
Front Vet Sci ; 9: 1035767, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36406076

RESUMO

The Spirometra mansoni is a neglect medical tapeworm, its plerocercoid larvae can parasitize in humans and animals, causing sparganosis. In this study, 17 new members of the glutathione transferase (GST) family were sequenced and characterized in S. mansoni. Clustering analysis displayed the categorization of SmGSTs into two main clades. RT-qPCR illustrated that 7 GST genes were highly expressed in the plerocercoid stage while 8 GSTs were highly expressed in the adult. rSmGST has the typical C- and N-terminal double domains of glutathione transferase. Immunolocalization revealed that natural SmGST is mainly located in the epidermis and parenchyma of plerocercoid, and in the epidermis, parenchyma, uterus and egg shell of adult worm. The optimum activity for rSmGST was found to be pH 6.5 and 25°C. The evolutionary tree showed a high level of diversity of cestodes GSTs. SmGSTs contained both conserved family members and members in the process of further diversification. The findings in this study will lay a foundation to better explore the underlying mechanisms of GSTs involved in Spirometra tapeworms.

5.
PLoS Negl Trop Dis ; 16(10): e0010881, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36315477

RESUMO

BACKGROUND: Pyruvate kinase widely exists in many parasites and plays an important role in the energy production for the parasites. Pyruvate kinase might be a potential drug target for killing the parasites. The aim of the present study was to evaluate the biological characteristics and roles of T. spiralis pyruvate kinase M (TsPKM) in sugar metabolism, larval molting and development of T. spiralis. METHODOLOGY/PRINCIPAL FINDINGS: TsPKM has two functional domains of pyruvate kinase and the tertiary structure of TsPKM is tetramer which has the enzyme active site constituted by 8 amino-acid residues (Arg71, Asn73, Asp110, Phe241, Lys267, Glu269, Asp293 and Thr325). Recombinant TsPKM (rTsPKM) was expressed and purified. The rTsPKM had good immunogenicity. RT-PCR and Western blot showed that TsPKM was transcribed and expressed at various developmental stages in T. spiralis lifecycle. Immunofluorescence test showed that TsPKM was principally located in the cuticle, muscle, stichosome, intestine and the intrauterine embryos of female adults. rTsPKM catalyzed the reaction of phosphoenolpyruvate (PEP) and adenosine diphosphate (ADP) to produce pyruvic acid and adenosine triphosphate (ATP). TsPKM played an important role in the metabolism and energy production of T. spiralis. After silencing of TsPKM gene by specific dsRNA-TsPKM2, protein expression and enzyme activity of TsPKM decreased by 50.91 and 26.06%, respectively. After treatment with RNAi, natural TsPKM enzyme activity, larval molting, sugar metabolism, growth and development of T. spiralis were significantly reduced. CONCLUSIONS: TsPKM participates in the larval molting, sugar metabolism, growth and development of T. spiralis and it might be a candidate target of therapeutic drug of trichinellosis.


Assuntos
Parasitos , Trichinella spiralis , Triquinelose , Animais , Feminino , Camundongos , Trichinella spiralis/genética , Piruvato Quinase/genética , Larva/fisiologia , Muda , Triquinelose/parasitologia , Parasitos/metabolismo , Açúcares , Camundongos Endogâmicos BALB C , Proteínas de Helminto/genética
6.
Nat Commun ; 13(1): 6067, 2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36241616

RESUMO

Atmospheric aerosol nucleation contributes to approximately half of the worldwide cloud condensation nuclei. Despite the importance of climate, detailed nucleation mechanisms are still poorly understood. Understanding aerosol nucleation dynamics is hindered by the nonreactivity of force fields (FFs) and high computational costs due to the rare event nature of aerosol nucleation. Developing reactive FFs for nucleation systems is even more challenging than developing covalently bonded materials because of the wide size range and high dimensional characteristics of noncovalent hydrogen bonding bridging clusters. Here, we propose a general workflow that is also applicable to other systems to train an accurate reactive FF based on a deep neural network (DNN) and further bridge DNN-FF-based molecular dynamics (MD) with a cluster kinetics model based on Poisson distributions of reactive events to overcome the high computational costs of direct MD. We found that previously reported acid-base formation rates tend to be significantly underestimated, especially in polluted environments, emphasizing that acid-base nucleation observed in multiple environments should be revisited.

7.
Vet Res ; 53(1): 85, 2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36258242

RESUMO

The aim of this study was to investigate the characteristics of a novel type C lectin from Trichinella spiralis (TsCTL) and its role in larval invasion of intestinal epithelial cells (IECs). TsCTL has a carbohydrate recognition domain (CRD) of C-type lectin. The full-length TsCTL cDNA sequence was cloned and expressed in Escherichia coli BL21. The results of qPCR, Western blotting and immunofluorescence assays (IFAs) showed that TsCTL was a surface and secretory protein that was highly expressed at the T. spiralis intestinal infective larva (IIL) stages and primarily located at the cuticle, stichosome and embryos of the parasite. rTsCTL could specifically bind with IECs, and the binding site was localized in the IEC nucleus and cytoplasm. The IFA results showed that natural TsCTL was secreted and bound to the enteral epithelium at the intestinal stage of T. spiralis infection. The rTsCTL had a haemagglutinating effect on murine erythrocytes, while mannose was able to inhibit the rTsCTL agglutinating effect for mouse erythrocytes. rTsCTL accelerated larval intrusion into the IECs, whereas anti-rTsCTL antibodies and mannose significantly impeded larval intrusion in a dose-dependent manner. The results indicated that TsCTL specifically binds to IECs and promotes larval invasion of intestinal epithelium, and it might be a potential target of vaccines against T. spiralis enteral stages.


Assuntos
Doenças dos Roedores , Trichinella spiralis , Triquinelose , Vacinas , Camundongos , Animais , Triquinelose/parasitologia , Triquinelose/veterinária , Larva/genética , DNA Complementar , Lectinas Tipo C/metabolismo , Manose/metabolismo , Proteínas de Helminto/metabolismo , Camundongos Endogâmicos BALB C , Células Epiteliais/metabolismo
8.
Exp Parasitol ; 242: 108376, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36089006

RESUMO

Aminopeptidases P are metalloproteases belonging to the M24 peptidase family. It specifically hydrolyzes the N-terminus of polypeptides free of acidic amino acids, and plays an important role in the nutrition, metabolism and growth of parasites. The aim of this study was to characterize a novel Trichinella spiralis aminopeptidase P (TsAPP) and to investigate its functions in the invasion of T. spiralis. TsAPP contained two domains of creatinase (a creatinase N and creatinase N2) and a domain of peptidase M24C and APP. The complete TsAPP sequence was cloned and expressed in Escherichia coli BL21 cells. The recombinantly produced TsAPP was used to raise polyclonal antibodies that were subsequently used to detect the expression of the protein in the different life stages of T. spiralis. TsAPP was expressed in various T. spiralis stages. TsAPP was primarily localized in the cuticle, stichosome and intrauterine embryos of this nematode. rTsAPP has an enzymatic activity of a natural aminopeptidase P to hydrolyze the substrate H-Ala-Pro-OH. rTsAPP promoted the larval intrusion of intestinal epithelium cells (IECs). The results showed that TsAPP is involved in the T. spiralis intrusion of IECs and it might be a potential candidate vaccine target against Trichinella infection.


Assuntos
Trichinella spiralis , Triquinelose , Vacinas , Camundongos , Animais , Proteínas de Helminto , Camundongos Endogâmicos BALB C , Triquinelose/parasitologia , Aminopeptidases/genética , Aminopeptidases/metabolismo , Células Epiteliais/parasitologia , Larva
9.
BMJ Open ; 12(9): e058568, 2022 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-36167375

RESUMO

INTRODUCTION: Emotional disorders are often observed in inflammatory bowel disease (IBD). IBD with emotional disorders leads to poor quality of life. This systematic review aims to assess the effectiveness of acupuncture in patients with IBD with emotional disorders. METHODS AND ANALYSIS: Nine electronic databases, including Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Allied and Complementary Medicine Database, Cumulative Index to Nursing & Allied Health Literature, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, VIP Database and Wanfang Database, will be searched from inception to October 2021 without language restriction. The grey literature containing conference proceedings, as well as systematic reviews listed in the reference of definite publications, will also be retrieved. Randomised controlled trials either in English or Chinese reporting acupuncture therapy for IBD with emotional disorders will be included. The primary outcome is changes of emotional functioning outcomes. The Colitis Activity Index, Crohn's Disease Activity Index, C reactive protein and adverse events will be assessed as the secondary outcomes. More than two assessors will conduct the study retrieval and selection, as well as the data extraction and evaluation of the risk of bias. Data synthesis will be performed using a random-effects model based on the results of heterogeneity. Data analysis will be performed using RevMan software (V.5.4). Moreover, the dichotomous data will be presented as risk ratios, and the continuous data will be calculated using weighted mean difference or standard mean difference. ETHICS AND DISSEMINATION: This systematic review contains no individual patient data; thus, ethical approval is not required. Moreover, this review will be disseminated in a peer-reviewed journal or relevant conference. PROSPERO REGISTRATION NUMBER: CRD42020176340.


Assuntos
Terapia por Acupuntura , Acupuntura , Doenças Inflamatórias Intestinais , Terapia por Acupuntura/métodos , Proteína C-Reativa , Doença Crônica , Humanos , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/terapia , Qualidade de Vida , Projetos de Pesquisa , Revisões Sistemáticas como Assunto
10.
Vet Res ; 53(1): 48, 2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35739604

RESUMO

Cathepsin L is an important cysteine protease, but its function in T. spiralis remains unclear. The aim of this research was to explore the biological characteristics of T. spiralis cathepsin L (TsCatL) and its role in T. spiralis-host interactions. Bioinformatic analysis revealed the presence of the cysteine protease active site residues Gln, Cys, His and Asn in mature TsCatL, as well as specific motifs of cathepsin L similar to ERFNIN and GYLND in the prepeptide of TsCatL. Molecular docking of mature TsCatL and E64 revealed hydrophobic effects and hydrogen bonding interactions. Two domains of TsCatL (TsCatL2) were cloned and expressed, and recombinant TsCatL2 (rTsCatL2) was autocatalytically cleaved under acidic conditions to form mature TsCatL. TsCatL was transcribed and expressed in larvae and adults and located in the stichosome, gut and embryo. Enzyme kinetic tests showed that rTsCatL2 degraded the substrate Z-Phe-Arg-AMC under acidic conditions, which was inhibited by E64 and PMSF and enhanced by EDTA, L-cysteine and DTT. The kinetic parameters of rTsCatL2 were a Km value of 48.82 µM and Vmax of 374.4 nM/min at pH 4.5, 37 °C and 5 mM DTT. In addition, it was shown that rTsCatL2 degraded haemoglobin, serum albumin, immunoglobulins (mouse IgG, human IgG and IgM) and extracellular matrix components (fibronectin, collagen I and laminin). The proteolytic activity of rTsCatL2 was host specific and significantly inhibited by E64. rTsCatL2 possesses the natural activity of a sulfhydryl-containing cysteine protease, and TsCatL is an important digestive enzyme that seems to be important for the nutrient acquisition, immune evasion and invasion of Trichinella in the host.


Assuntos
Cisteína Proteases , Trichinella spiralis , Animais , Catepsina L/genética , Cisteína Proteases/metabolismo , Imunoglobulina G , Camundongos , Simulação de Acoplamento Molecular
11.
PLoS Negl Trop Dis ; 16(5): e0010395, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35500031

RESUMO

BACKGROUND: A range of helminth species involve the migration of developing larvae through the lung and establish chronic infections in the host that include potent immune regulatory effects. Trichinella spiralis is one of the most successful parasitic symbiotes. After released by intestinal female adult worms, newborn larvae of T. spiralis travel through the circulatory system to the lung and finally reach skeletal muscle cells. As unique inflammation modulator of intracellular parasitism, T. spiralis shows improved responses to autoimmune disease and viral pulmonary inflammation by exerting immunomodulatory effects on innate and adaptive immune cells. METHODOLOGY/PRINCIPAL FINDINGS: C57BL/6 mice were divided into four groups: uninfected; helminth- T. spiralis infected; P. aeruginosa infected; and co-infected. Mice infected with T. spiralis were incubated for 6 weeks, followed by P. aeruginosa intranasal inoculation. Bronchial alveolar lavage fluid, blood and lung samples were analyzed. We found that T. spiralis induced Th2 response in the mouse lung tissue, increased lung CD4+ T cells, GATA3, IL-4, IL-5 and IL-13 expression. Pre-existing T. spiralis infection decreased lung neutrophil recruitment, inflammatory mediator IL-1ß and IL-6 expression and chemokine CXCL1 and CXCL2 release during P. aeruginosa- pneumonia. Furthermore, T. spiralis co-infected mice exhibited significantly more eosinophils at 6 hours following P. aeruginosa infection, ameliorated pulmonary inflammation and improved survival in P. aeruginosa pneumonia. CONCLUSIONS: These findings indicate that a prior infection with T. spiralis ameliorates experimental pulmonary inflammation and improves survival in P. aeruginosa pneumonia through a Th2-type response with eosinophils.


Assuntos
Pneumonia , Trichinella spiralis , Triquinelose , Animais , Citocinas/metabolismo , Feminino , Helmintíase , Enteropatias Parasitárias , Camundongos , Camundongos Endogâmicos C57BL , Pseudomonas aeruginosa/metabolismo
12.
Acta Trop ; 232: 106483, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35469749

RESUMO

The plerocercoid larvae of the tapeworm Spirometra erinaceieuropaei can parasitize humans and animals and cause serious parasitic zoonosis. However, our knowledge of the developmental process of S. erinaceieuropaei is still inadequate. To better characterize differential and specific genes and pathways associated with parasite development, a comparative transcriptomic analysis of the plerocercoid stage and the adult stage was performed using RNA-seq and de novo analysis. Approximately 13,659 differentially expressed genes (DEGs) were identified in plerocercoids versus adults, of which 6455 DEGs were upregulated and 7204 were downregulated. DEGs involved in parasite immunoevasion were more active in plerocercoid larvae than in adults, while DEGs associated with metabolic activity were upregulated in adults. Gene Ontology (GO) and Kyoto Encyclopedia of Genes (KEGG) analyses revealed that most DEGs involved in protein phosphorylation/dephosphorylation and the Wnt signalling pathway were much more active in plerocercoid larvae. The molecular functions of upregulated unigenes in adults were mainly enriched for metabolic activities. qPCR validated that the expression levels of 10 selected DEGs were consistent with those in RNA-seq, confirming the accuracy of the RNA-seq results. Our results contributed to increasing the knowledge on the S. erinaceieuropaei gene repertoire and expression profile and also provide valuable resources for functional studies on the molecular mechanisms of S. erinaceieuropaei.


Assuntos
Infecções por Cestoides , Esparganose , Spirometra , Animais , Perfilação da Expressão Gênica , Esparganose/parasitologia , Spirometra/genética , Transcriptoma , Zoonoses
13.
Vet Res ; 53(1): 19, 2022 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-35255974

RESUMO

The intestinal epithelium is the first natural barrier against Trichinella spiralis larval invasion, but the mechanism of larval invasion of the gut epithelium is not fully elucidated. The aim of this study was to investigate whether the excretory/secretory proteins (ESPs) of T. spiralis intestinal infective larvae (IIL) degrade tight junction (TJ) proteins, to assess the main ESP proteases hydrolysing TJ proteins using various enzyme inhibitors and to define the key invasive factors in IIL invasion of the gut epithelium. The results of immunofluorescence, Western blot and Transwell assays showed that serine proteases and cysteine proteases in the ESPs played main roles in hydrolysing occludin, claudin-1 and E-cad and upregulating claudin-2 expression. Challenge infection results showed that IIL expulsion from the gut at 12 hpi was significantly higher in mice which were infected with muscle larvae (ML) treated with a single inhibitor (PMSF, E-64, 1,10-Phe or pepstatin) or various mixtures containing PMSF and E-64 than in mice in the PBS group or the groups treated with an inhibitor mixture not containing PMSF and E-64 (P < 0.0001). At 6 days post-infection, mice which were infected with ML treated with PMSF, E-64, 1,10-Phe or pepstatin exhibited 56.30, 64.91, 26.42 and 31.85% reductions in intestinal adult worms compared to mice in the PBS group (P < 0.0001). The results indicate that serine proteases and cysteine proteases play key roles in T. spiralis IIL invasion, growth and survival in the host and that they may be main candidate target molecules for vaccines against larval invasion and development.


Assuntos
Doenças dos Roedores , Trichinella spiralis , Triquinelose , Animais , Células Epiteliais/metabolismo , Proteínas de Helminto/metabolismo , Larva , Camundongos , Camundongos Endogâmicos BALB C , Serina Proteases , Trichinella spiralis/fisiologia , Triquinelose/veterinária
14.
Acta Trop ; 229: 106388, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35231417

RESUMO

Trichinellosis is an important meat-borne zoonotic parasitic disease caused by ingesting raw or semi-cooked meat of pigs and other animals infected with Trichinella sp. muscle larvae. Epidemiological data on human and animal Trichinella sp. infection in the People's Republic of China (PRC) during 2009-2020 were analyzed in this review. The results showed that the endemic foci of human trichinellosis are principally localized in southwestern areas, and eight outbreaks covering 479 cases and 2 deaths were reported. Pork is still the primary source of trichinellosis outbreaks. Seven out of 8 outbreaks (87.50%) were caused by ingesting raw or semi-cooked pork. The seroprevalence of swine anti-Trichinella IgG ranged from 0 to 42.11% in 11 provinces/autonomous regions  (P/As), and swine Trichinella infection was detected in six P/A slaughterhouses. The Trichinella-infected pigs came from small backyard farms and outdoor free-ranging pigs in western and southwestern PRC. To prevent trichinellosis, the traditional pig-rearing mode should be improved, more industrialized pig farms should be developed, all pigs should be raised in piggeries under controlled management conditions, and mandatory inspection of Trichinella sp. in slaughtered pigs should be implemented in rural areas of western and southwestern PRC. A One Health approach with participation from governments, public health officials, and medical and veterinary practitioners is vital for controlling zoonotic foodborne trichinellosis.


Assuntos
Doenças dos Suínos , Trichinella , Triquinelose , Animais , China/epidemiologia , Surtos de Doenças , Humanos , Carne/parasitologia , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/epidemiologia , Triquinelose/epidemiologia , Triquinelose/parasitologia
15.
Acta Trop ; 226: 106263, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34879232

RESUMO

Elastase belongs to the serine protease family. Previous studies showed that Trichinella spiralis elastase (TsE) was highly expressed in intestinal infective larvae (IIL). Recombinant TsE (rTsE) promoted the larval intrusion of enteral epithelium cells (IECs), whereas anti-rTsE antibodies and siRNA impeded larval intrusion. Subcutaneous vaccination of mice with rTsE showed a partial protective immunity, suggesting that TsE might be a promising vaccine target against Trichinella infection. In this study, complete TsE cDNA sequence was cloned into pcDNA3.1, and the rTsE DNA was transformed into attenuated S. typhimurium strain ΔcyaSL1344. Oral vaccination of mice with TsE DNA elicited a systemic Th1/Th2/Treg mixed immune response and gut local mucosal sIgA response. Immunized mice exhibited a significant immune protection against T. spiralis larval challenge, as demonstrated by a 52.48% reduction of enteral adult worms and a 69.43% reduction of muscle larvae. The protection might be related to the TsE-induced production of intestinal mucus, specific anti-TsE sIgA and IgG, and secretion of IFN-γ, IL-2, IL-4 and IL-10, which protected gut mucosa from larval intrusion, suppressed worm development and impeded female reproduction. The results demonstrated that attenuated Salmonella-delivered TsE DNA vaccine provided a prospective strategy for the control of Trichinella infection in food animals.


Assuntos
Trichinella spiralis , Triquinelose , Vacinas de DNA , Animais , Anticorpos Anti-Helmínticos , Feminino , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Elastase Pancreática , Estudos Prospectivos , Salmonella typhimurium/genética , Trichinella spiralis/genética , Triquinelose/prevenção & controle , Vacinação , Vacinas de DNA/genética
16.
PLoS Negl Trop Dis ; 15(10): e0009865, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34699522

RESUMO

BACKGROUND: Trichinellosis is a serious zoonotic disease distributed around the world. It is needed to develop a safe, effective and feasible anti-Trichinella vaccine for prevention and control of trichinellosis. The aim of this study was to construct a recombinant Lactobacillus plantarum encoding Trichinella spiralis inorganic pyrophosphatase (TsPPase) and investigate its immune protective effects against T. spiralis infection. METHODOLOGY/PRINCIPAL FINDINGS: The growth of recombinant L. plantarum was not affected by TsPPase/pSIP409-pgsA' plasmid, and the recombinant plasmid was inherited stably in bacteria. Western blot and immunofluorescence assay (IFA) indicated that the rTsPPase was expressed on the surface of recombinant L. plantarum. Oral vaccination with rTsPPase induced higher levels of specific serum IgG, IgG1, IgG2a and mucosal secretory IgA (sIgA) in BALB/c mice. ELISA analysis revealed that the levels of IFN-γ and IL-4 released from spleen, mesenteric lymph nodes and Peyer's patches were evidently increased at 2-4 weeks following vaccination, compared to MRS (De Man, Rogosa, Sharpe) medium control group (P < 0.05). Immunization of mice with rTsPPase exhibited a 67.18, 54.78 and 51.91% reduction of intestinal infective larvae, adult worms and muscle larvae at 24 hours post infection (hpi), 6 days post infection (dpi) and 35 dpi, respectively (P < 0.05), and the larval molting and development was significantly inhibited by 45.45% at 24 hpi, compared to the MRS group. CONCLUSIONS: TsPPase plays a crucial role in T. spiralis molting and development, oral vaccination with rTsPPase induced a significant local mucosal sIgA response and systemic Th1/Th2 immune response, and immune protection against T. spiralis infection in BALB/c mice.


Assuntos
Proteínas de Helminto/administração & dosagem , Pirofosfatase Inorgânica/administração & dosagem , Lactobacillus plantarum/genética , Trichinella spiralis/imunologia , Triquinelose/prevenção & controle , Vacinas/administração & dosagem , Administração Oral , Animais , Anticorpos Anti-Helmínticos/imunologia , Feminino , Proteínas de Helminto/genética , Proteínas de Helminto/imunologia , Humanos , Imunoglobulina G/imunologia , Pirofosfatase Inorgânica/genética , Pirofosfatase Inorgânica/imunologia , Lactobacillus plantarum/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Trichinella spiralis/enzimologia , Trichinella spiralis/genética , Triquinelose/imunologia , Triquinelose/parasitologia , Vacinação , Vacinas/genética , Vacinas/imunologia
17.
Parasit Vectors ; 14(1): 537, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34649597

RESUMO

BACKGROUND: Necator americanus is one of the major etiological agents of human ancylostomiasis. Historically, the epidemiology of ancylostomiasis in Henan Province of central China and the molecular characteristics of N. americanus have been poorly understood. METHODS: In this study, we report a case of ancylostomiasis in Zhengzhou city of Henan Province. We also review the epidemiology of ancylostomiasis in Henan Province from 1949 to 2020. In addition, the complete mitochondrial (mt) genome of one clinical isolate is fully characterized using Illumina sequencing. All available mt genomes of hookworms in GenBank were included to reconstruct the phylogeny using both maximum likelihood (ML) and Bayesian inference (BI) methods. RESULTS: A total of three worms were collected from the patient. These worms were identified as N. americanus based on morphological characteristics as well as confirmed by genotyping with the barcoding gene cox1. Although ancylostomiasis cases have dropped substantially in recent years, hookworm infection is still a public health problem in underdeveloped areas and remote rural areas in Henan Province. The mt genome features of the N. americanus contained 12 protein-coding genes (PCGs), 22 transfer RNA genes, two ribosomal RNA genes, and a major non-coding region. The nad1 gene showed high sequence variability among isolates, which is worth considering for future genetic studies of N. americanus. Phylogenetic analyses support the monophyly of hookworm isolates from different hosts and distinct geographical locations. CONCLUSIONS: The mt genome of N. americanus presented here will serve as a useful data set for studying population genetics and phylogenetic relationships of hookworms. Positive measures for preventing and controlling ancylostomiasis are required by both health services and individuals in Henan Province.


Assuntos
Ancilostomíase/epidemiologia , Genoma Helmíntico , Técnicas de Diagnóstico Molecular , Necator americanus/genética , Necatoríase/diagnóstico , Necatoríase/epidemiologia , Idoso , Animais , China/epidemiologia , DNA de Helmintos/genética , Feminino , Humanos , Necator americanus/isolamento & purificação
18.
Int J Biol Macromol ; 192: 883-894, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34656542

RESUMO

Trichinellosis is a serious food-borne zoonotic parasitic disease with global distribution, causing serious harm to public health and food safety. Molting is prerequisite for intestinal larval development in the life cycle of T. spiralis. Metalloproteinases play an important role in the molting process of T. spiralis intestinal infective larvae (IIL). In this study, the metalloproteinase Tsdpy31 was cloned, expressed and characterized. The results revealed that the Tsdpy31 was expressed at various T. spiralis stages and it was principally located in cuticle, hypodermis and embryos of the nematode. Recombinant Tsdpy31 (rTsdpy31) had the catalytic activity of natural metalloproteinase. Silencing of Tsdpy31 increased the permeability of larval new cuticle. When the mice were orally challenged with dsRNA treated- muscle larvae, the burden of intestinal adult and muscle larvae in Tsdpy31 dsRNA treatment group was significantly reduced, compared with the control green fluorescent protein (GFP) dsRNA and PBS groups (P < 0.05). Tsdpy31 may play a major role in the new cuticle synthesis and old cuticle shedding. Tsdpy31 also participates in T. spiralis embryonic development. We conclude that Tsdpy31 could be a candidate vaccine target molecule against intestinal T. spiralis ecdysis and development.


Assuntos
Metaloproteases/química , Metaloproteases/metabolismo , Metamorfose Biológica , Muda , Trichinella spiralis/fisiologia , Processamento Alternativo , Sequência de Aminoácidos , Animais , Biologia Computacional/métodos , Ativação Enzimática , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Proteínas de Helminto/química , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Larva , Metaloproteases/genética , Muda/genética , Mutação , Filogenia , Conformação Proteica , Interferência de RNA , Relação Estrutura-Atividade , Trichinella spiralis/isolamento & purificação
19.
Acta Trop ; 224: 106112, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34453915

RESUMO

Cathepsin L is one member of cysteine protease superfamily and widely distributed in parasitic organisms, it plays the important roles in worm invasion, migration, nutrient intake, molting and immune evasion. The objective of this study was to investigate the biological characteristics of a novel cathepsin L from Trichinella spiralis (TsCL) and its role in larval invasion, development and reproduction. TsCL has a functional domain of C1 peptidase, which belongs to cathepsin L family. The complete TsCL sequence was cloned and expressed in Escherichia coli BL21. The rTsCL has good immunogenicity. RT-PCR and Western blotting analysis showed that TsCL was transcribed and expressed at different T. spiralis phases (e.g., muscle larvae, intestinal infectious larvae, adult worms and newborn larvae). Immunofluorescence test revealed that TsCL was principally localized in the cuticle, stichosome, midgut and female intrauterine embryos of the nematode. rTsCL has the capacity to specially bind with intestinal epithelial cells (IECs) and the binding sites was located in the cytoplasm. rTsCL promoted larval penetration into IEC, while anti-rTsCL antibodies inhibited the invasion. The silencing of TsCL gene by specific dsRNA significantly reduced the TsCL expression and enzyme activity, and also reduced larval invasive ability, development and female reproduction. The results showed that TsCL is an obligatory protease in T. spiralis lifecycle. TsCL participates in worm invasion, development and reproduction, and may be regarded as a potential candidate vaccine/drug target against T. spiralis infection.


Assuntos
Trichinella spiralis , Triquinelose , Animais , Catepsina L , Feminino , Proteínas de Helminto , Larva/genética , Camundongos , Camundongos Endogâmicos BALB C , Reprodução , Trichinella spiralis/genética
20.
Vet Res ; 52(1): 113, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34446106

RESUMO

The aim of this study was to investigate the biological properties of a novel gut-specific cysteine protease in Trichinella spiralis (TsGSCP) and its role in larval intrusion, development and fecundity. TsGSCP has a functional C1 peptidase domain; C1 peptidase belongs to cathepsin B family. The TsGSCP gene cloned and expressed in Escherichia coli BL21 showed intensive immunogenicity. qPCR and Western blotting revealed that TsGSCP mRNA and protein were expressed at various T. spiralis stages, but their expression levels in intestinal infectious larvae (IIL) were clearly higher than those in muscle larvae (ML), adult worms (AWs) and new-born larvae (NBL). Indirect immunofluorescence (IIF) analysis showed that TsGSCP was primarily located at the outer cuticle and the intrauterine embryos of this parasite. rTsGSCP showed the ability to specifically bind with IECs, and the binding site is within the IEC cytoplasm. rTsGSCP accelerated larval intrusion into host intestinal epithelial cells (IECs), whereas anti-rTsGSCP antibodies suppressed larval intrusion; the acceleration and suppression was induced by rTsGSCP and anti-rTsGSCP antibodies, respectively, in a dose-dependent manner. When ML were transfected with TsGSCP-specific dsRNA, TsGSCP expression and enzymatic activity were reduced by 46.82 and 37.39%, respectively, and the capacity of the larvae to intrude into IECs was also obviously impeded. Intestinal AW burden and adult female length and fecundity were significantly decreased in the group of mice infected with dsRNA-transfected ML compared to the control dsRNA and PBS groups. The results showed that TsGSCP plays a principal role in gut intrusion, worm development and fecundity in the T. spiralis lifecycle and might be a candidate target for vaccine development against Trichinella intrusion and infection.


Assuntos
Cisteína Proteases/genética , Proteínas de Helminto/genética , Trichinella spiralis/fisiologia , Sequência de Aminoácidos , Animais , Cisteína Proteases/química , Cisteína Proteases/metabolismo , Feminino , Fertilidade , Proteínas de Helminto/química , Proteínas de Helminto/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Larva/fisiologia , Camundongos , Filogenia , Alinhamento de Sequência/veterinária , Trichinella spiralis/genética , Trichinella spiralis/crescimento & desenvolvimento , Trichinella spiralis/metabolismo , Triquinelose/veterinária
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