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Excretory/secretory proteins of adult Toxocara canis induce changes in the expression of proteins involved in the NOD1-RIP2-NF-κB pathway and modulate cytokine production in mouse macrophages. Exp Parasitol 2021; 229:108152. [PMID: 34419413 DOI: 10.1016/j.exppara.2021.108152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 08/09/2021] [Accepted: 08/18/2021] [Indexed: 01/16/2023]
Abstract
Dog roundworm (Toxocara canis) is the major causative agent of toxocarosis, a parasitic disease of both veterinary and medical importance. Knowledge gaps in fundamental and applied aspects hinder the control of this important zoonotic disease. To have a better understanding of Toxocara infection and host immune responses, mouse macrophages were exposed to excretory/secretory (ES) proteins released by adult worms of T. canis in vitro. The messenger RNA transcription and protein expression of nucleotide-binding oligomerization domain-containing protein 1 (NOD1), receptor interacting protein 2 (RIP2) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in macrophages were analysed using quantitative real-time PCR (qRT-PCR) and Western blot. The levels of tumour necrosis factor alpha (TNF-ɑ), interleukin-1 beta (IL-1β) and IL-6 released by the stimulated macrophages were analysed using enzyme-linked immunosorbent assay. It was found that 20 μg/mL ES proteins of adult T. canis induced the expression of NOD1, RIP2 and NF-κB in mouse macrophages at both transcriptional and translational levels after 9 h of incubation in vitro. Incubation with 20 μg/mL ES proteins also modulated the production of pro-inflammatory cytokines TNF-ɑ, IL-1β and IL-6 by the macrophages. Taken together, ES proteins of adult T. canis appeared to be able to affect the macrophage NOD1-RIP2-NF-κB signalling pathway, which might play a role in regulating the production of proinflammatory cytokines. Further investigation of these aspects should lead to a better understanding of immune recognition of and modulation by Toxocara canis in host animals.
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Zheng WB, Zou Y, Zhu XQ, Liu GH. Toxocara "omics" and the promises it holds for medicine and veterinary medicine. ADVANCES IN PARASITOLOGY 2020; 109:89-108. [PMID: 32381233 DOI: 10.1016/bs.apar.2020.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Toxocariasis is one of the most neglected worldwide zoonoses that is caused by larval nematode parasites of the genus Toxocara, Toxocara canis, and to a lesser extent, Toxocara cati, whose migration mechanism is still largely unknown. Fortunately, some advanced tools have been employed, such as genomics, transcriptomics, and proteomics, to better understand the molecular biology and regulatory mechanisms of Toxocara. Using genomics and transcriptomics, we can identify a large number of genes that participate in the development of Toxocara and the interaction of parasites and their hosts and can predict the functions of unknown genes by comparing them with other relevant species. Using proteomics, we can identify somatic proteins and excretory and secretory (ES) proteins that perform specific biological functions in tissue degradation, pathogen invasion, immune evasion or modulation. These "omics" techniques also can contribute enormously to the development of new drugs, vaccines and diagnostic tools for toxocariasis. In a word, by utilizing "omics", we can better understand the Toxocara and toxocariasis. In this review, we summarized the representative achievements in Toxocara and the interaction between Toxocara spp. and their hosts based on expressed sequence tags (ESTs), microarray gene expression, next-generation sequencing (NGS) technologies and liquid chromatography-tandem mass spectrometry (LC-MS/MS), hoping to better understand the molecular biology of Toxocara, and contribute to new progress in the application areas of new drugs, vaccines and diagnostic tool for toxocariasis in the future.
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Affiliation(s)
- Wen-Bin Zheng
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China; State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Yang Zou
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China; Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, China.
| | - Guo-Hua Liu
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China.
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Gasser RB, Korhonen PK, Zhu XQ, Young ND. Harnessing the Toxocara Genome to Underpin Toxocariasis Research and New Interventions. ADVANCES IN PARASITOLOGY 2016; 91:87-110. [PMID: 27015948 DOI: 10.1016/bs.apar.2015.12.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Parasitic worms, such as flatworms (platyhelminths) and roundworms (nematodes), cause substantial morbidity and mortality in animals and people globally. The ascaridoid nematode Toxocara canis is a zoonotic parasite of socioeconomic significance worldwide. In humans, this worm causes toxocariasis (disease) mainly in underprivileged communities in both the developed and developing worlds. While reasonably well studied from clinical and epidemiological perspectives, little is understood about the molecular biology of T. canis, its relationship with its hosts and the disease that it causes. However, a recent report of the draft genome and transcriptomes of T. canis should underpin many fundamental and applied research areas in the future. The present article gives a background on Toxocara and toxocariasis, a brief account of diagnostic approaches for specific identification and genetic analysis, and gives a perspective on the impact that the genome of T. canis and advanced molecular technologies could have on our understanding of the parasite and the diseases that it causes as well as the design of new and improved approaches for the diagnosis, treatment and control of toxocariasis.
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Hu L, Zhao Y, Cheng J, Yang Y, Li C, Lu Z. Constructing and detecting a cDNA library for mites. Parasitol Res 2015; 114:3893-901. [PMID: 26174488 DOI: 10.1007/s00436-015-4621-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/02/2015] [Indexed: 01/09/2023]
Abstract
RNA extraction and construction of complementary DNA (cDNA) library for mites have been quite challenging due to difficulties in acquiring tiny living mites and breaking their hard chitin. The present study is to explore a better method to construct cDNA library for mites that will lay the foundation on transcriptome and molecular pathogenesis research. We selected Psoroptes cuniculi as an experimental subject and took the following steps to construct and verify cDNA library. First, we combined liquid nitrogen grinding with TRIzol for total RNA extraction. Then, switching mechanism at 5' end of the RNA transcript (SMART) technique was used to construct full-length cDNA library. To evaluate the quality of cDNA library, the library titer and recombination rate were calculated. The reliability of cDNA library was detected by sequencing and analyzing positive clones and genes amplified by specific primers. The results showed that the RNA concentration was 836 ng/μl and the absorbance ratio at 260/280 nm was 1.82. The library titer was 5.31 × 10(5) plaque-forming unit (PFU)/ml and the recombination rate was 98.21%, indicating that the library was of good quality. In the 33 expressed sequence tags (ESTs) of P. cuniculi, two clones of 1656 and 1658 bp were almost identical with only three variable sites detected, which had an identity of 99.63% with that of Psoroptes ovis, indicating that the cDNA library was reliable. Further detection by specific primers demonstrated that the 553-bp Pso c II gene sequences of P. cuniculi had an identity of 98.56% with those of P. ovis, confirming that the cDNA library was not only reliable but also feasible.
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Affiliation(s)
- Li Hu
- Department of Pathogen Biology and Immunology, Xi'an Jiaotong University Health Science Center, No.76 Yanta West Road, Xi'an, 710061, China
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Morphological and molecular characterization of Nosema pernyi, a microsporidian parasite in Antheraea pernyi. Parasitol Res 2015; 114:3327-36. [DOI: 10.1007/s00436-015-4558-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 05/25/2015] [Indexed: 10/23/2022]
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Ma GX, Zhou RQ, Hu SJ, Huang HC, Zhu T, Xia QY. Molecular characterization and functional analysis of serine/threonine protein phosphatase of Toxocara canis. Exp Parasitol 2014; 141:55-61. [PMID: 24657583 DOI: 10.1016/j.exppara.2014.03.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 03/12/2014] [Indexed: 11/19/2022]
Abstract
Toxocara canis (T. canis) is a widely prevalent zoonotic parasite that infects a wide range of mammalian hosts, including humans. We generated the full-length complementary DNA (cDNA) of the serine/threonine phosphatase gene of T. canis (Tc stp) using 5' rapid amplification of the cDNA ends. The 1192-bp sequence contained a continuous 942-nucleotide open reading frame, encoding a 313-amino-acid polypeptide. The Tc STP polypeptide shares a high level of amino-acid sequence identity with the predicted STPs of Loa loa (89%), Brugia malayi (86%), Oesophagostomum columbianum (76%), and Oesophagostomumdentatum (76%). The Tc STP contains GDXHG, GDXVDRG, GNHE motifs, which are characteristic of members of the phosphoprotein phosphatase family. Our quantitative real-time polymerase chain reaction analysis showed that the Tc STP was expressed in six different tissues in the adult male, with high-level expression in the spermary, vas deferens, and musculature, but was not expressed in the adult female, suggesting that Tc STP might be involved in spermatogenesis and mating behavior. Thus, STP might represent a potential molecular target for controlling T. canis reproduction.
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Affiliation(s)
- Guang Xu Ma
- Department of Veterinary Medicine, Rongchang Campus, Southwest University, Chongqing 402460, People's Republic of China
| | - Rong Qiong Zhou
- Department of Veterinary Medicine, Rongchang Campus, Southwest University, Chongqing 402460, People's Republic of China.
| | - Shi Jun Hu
- Department of Veterinary Medicine, Rongchang Campus, Southwest University, Chongqing 402460, People's Republic of China
| | - Han Cheng Huang
- Department of Veterinary Medicine, Rongchang Campus, Southwest University, Chongqing 402460, People's Republic of China
| | - Tao Zhu
- Department of Veterinary Medicine, Rongchang Campus, Southwest University, Chongqing 402460, People's Republic of China
| | - Qing You Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, People's Republic of China.
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Kim KU, Park SK, Kang SA, Park MK, Cho MK, Jung HJ, Kim KY, Yu HS. Comparison of functional gene annotation of Toxascaris leonina and Toxocara canis using CLC genomics workbench. THE KOREAN JOURNAL OF PARASITOLOGY 2013; 51:525-30. [PMID: 24327777 PMCID: PMC3857499 DOI: 10.3347/kjp.2013.51.5.525] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 07/23/2013] [Accepted: 08/09/2013] [Indexed: 12/24/2022]
Abstract
The ascarids, Toxocara canis and Toxascaris leonina, are probably the most common gastrointestinal helminths encountered in dogs. In order to understand biological differences of 2 ascarids, we analyzed gene expression profiles of female adults of T. canis and T. leonina using CLC Genomics Workbench, and the results were compared with those of free-living nematode Caenorhabditis elegans. A total of 2,880 and 7,949 ESTs were collected from T. leonina and T. canis, respectively. The length of ESTs ranged from 106 to 4,637 bp with an average insert size of 820 bp. Overall, our results showed that most functional gene annotations of 2 ascarids were quite similar to each other in 3 major categories, i.e., cellular component, biological process, and molecular function. Although some different transcript expression categories were found, the distance was short and it was not enough to explain their different lifestyles. However, we found distinguished transcript differences between ascarid parasites and free-living nematodes. Understanding evolutionary genetic changes might be helpful for studies of the lifestyle and evolution of parasites.
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Affiliation(s)
- Ki Uk Kim
- Department of Internal Medicine, School of Medicine, Pusan National University, Yangsan 626-870, Korea
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A perfect time to harness advanced molecular technologies to explore the fundamental biology of Toxocara species. Vet Parasitol 2013; 193:353-64. [DOI: 10.1016/j.vetpar.2012.12.031] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
Toxocara canis has extraordinary abilities to survive for many years in the tissues of diverse vertebrate species, as well as to develop to maturity in the intestinal tract of its definitive canid host. Human disease is caused by larval stages invading musculature, brain and the eye, and immune mechanisms appear to be ineffective at eliminating the infection. Survival of T. canis larvae can be attributed to two molecular strategies evolved by the parasite. Firstly, it releases quantities of 'excretory-secretory' products which include lectins, mucins and enzymes that interact with and modulate host immunity. For example, one lectin (CTL-1) is very similar to mammalian lectins, required for tissue inflammation, suggesting that T. canis may interfere with leucocyte extravasation into infected sites. The second strategy is the elaboration of a specialised mucin-rich surface coat; this is loosely attached to the parasite epicuticle in a fashion that permits rapid escape when host antibodies and cells adhere, resulting in an inflammatory reaction around a newly vacated focus. The mucins have been characterised as bearing multiple glycan side-chains, consisting of a blood-group-like trisaccharide with one or two O-methylation modifications. Both the lectins and these trisaccharides are targeted by host antibodies, with anti-lectin antibodies showing particular diagnostic promise. Antibodies to the mono-methylated trisaccharide appear to be T. canis-specific, as this epitope is not found in the closely related Toxocara cati, but all other antigenic determinants are very similar between the two species. This distinction may be important in designing new and more accurate diagnostic tests. Further tools to control toxocariasis could also arise from understanding the molecular cues and steps involved in larval development. In vitro-cultivated larvae express high levels of four mRNAs that are translationally silenced, as the proteins they encode are not detectable in cultured larvae. However, these appear to be produced once the parasite has entered the mammalian host, as they are recognised by specific antibodies in infected patients. Elucidating the function of these genes, or analysing if micro-RNA translational silencing suppresses production of the proteins, may point towards new drug targets for tissue-phase parasites in humans.
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Affiliation(s)
- Rick M Maizels
- Institute of Immunology and Infection Research, University of Edinburgh, Ashworth Laboratories, West Mains Road, Edinburgh EH9 3JT, United Kingdom.
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