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Li R, Zhang B, Chen C. Comparison of structures and inhibition activities of serine protease inhibitors of Trichinella spiralis and Trichinella pseudospiralis. Cell Biosci 2025; 15:35. [PMID: 40082967 PMCID: PMC11905679 DOI: 10.1186/s13578-025-01375-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2024] [Accepted: 02/28/2025] [Indexed: 03/16/2025] Open
Abstract
BACKGROUND Trichinosis is one of the most widespread parasitic infections worldwide. Trichinella spiralis not only infects humans but can also utilize wild anddomestic animals as hosts. The serine protease inhibitors secreted by Trichinella spiralis play a critical role in its invasion and immune evasion. Serpins can effectively inhibit host proteases, although the host can mount a strongimmune response against to these inhibitors. RESULTS In this study we analyzed the crystal structures of the serine protease inhibitors from Trichinella spiralis and Trichinella pseudospiralis, revealing that both serpins exhibit.structural characteristics typical of serine protease inhibitors. The similarity of both "breach" region and "shutter" region of the two serpins are very high, but the "hinge" region are different, the "hinge" of Tp-serpin is closed, while of Ts-serpin was partially inserted into sheet-A, suggesting that Tp-serpin had higher inhibition activity. Using alpha chymotrypsin as Ts-serpin and Tp-serpin protease targets, the two serpins enzyme inhibition activity were measured separately, by measuring the secondary inhibition rate constant, half inhibitory concentration IC50, inhibition of stoichiometric number parameters and confirmed both the serine protease inhibitory activity, and Tp-serpin slightly higher than that of Ts-serpin, but no inhibition activity of P1-P1' mutant. CONCLUSION In this study, the mechanism of enzyme inhibition activity of serpin was studied by means of structural biology and biochemistry comprehensively. These discoveries provide a theoretical foundation for a deeper understanding of the inhibition mechanisms of serpins and for the development of new drugs and vaccines against Trichinella spiralis infection.
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Affiliation(s)
- Ruixue Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, 300070, China
| | - Bing Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, 300070, China
| | - Chen Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, 300070, China.
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2
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Chaimon S, Phuphisut O, Reamtong O, Ampawong S, Fongsodsri K, Chantree P, Thanongsaksrikul J, Malaithong P, Sreesai S, Maleewong W, Sadaow L, Martviset P, Adisakwattana P. Molecular and biological characterization of transforming growth factor-β homolog derived from Trichinella spiralis. Sci Rep 2024; 14:31229. [PMID: 39732815 DOI: 10.1038/s41598-024-82599-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2024] [Accepted: 12/06/2024] [Indexed: 12/30/2024] Open
Abstract
The cytokine homologs, particularly transforming growth factor (TGF)-β, is a crucial immunomodulatory molecule and involved in growth and developmental processes in several helminths. In this study, the basic properties and functions of T. spiralis TGF-β homolog 2 (TsTGH2) were characterized using bioinformatics and molecular biology approaches. Bioinformatics analyses indicated that TsTGH2 belongs to the TGF-β subfamily. Recombinant TsTGH2 (rTsTGH2) expressed in Escherichia coli was used to produce a polyclonal antibody (pAb) in mice. Western blot and immunolocalization using pAb detected native TsTGH2 in crude worm antigens from muscle larvae and adults, showing it was mainly localized in the body wall muscles and the epithelia of the ovary and uterus. To assess the interplay between TsTGH2 and the human TGF-β signaling pathway, rTsTGH2 produced in a HEK293T cell was incubated with the SBE luciferase-HEK293 cell. The result indicated a significant increase in luciferase activity after treatment with rTsTGH2 compared to untreated control (p < 0.05). In conclusion, these findings are the first to characterize the basic properties and functions of TGF-β homologs in T. spiralis, demonstrating their interaction with the human TGF-β receptor. Further investigation is required to identify and optimize an appropriate expression system or conditions for TsTGH2. Additionally, studies are needed to clarify the specific role of native TsTGH2 in parasite development and host immunomodulation.
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Affiliation(s)
- Salisa Chaimon
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
- Department of Preclinical Science, Faculty of Medicine, Thammasat University, Pathumthani, 12120, Thailand
- Graduate Program in Applied Biosciences, Faculty of Medicine, Thammasat University, Pathumthani, 12120, Thailand
| | - Orawan Phuphisut
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Onrapak Reamtong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Sumate Ampawong
- Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Kamonpan Fongsodsri
- Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Pathanin Chantree
- Department of Preclinical Science, Faculty of Medicine, Thammasat University, Pathumthani, 12120, Thailand
- Graduate Program in Applied Biosciences, Faculty of Medicine, Thammasat University, Pathumthani, 12120, Thailand
- Thammasat University Research Unit in Nutraceuticals and Food Safety, Thammasat University, Pathumthani, 12120, Thailand
| | - Jeeraphong Thanongsaksrikul
- Graduate Program in Biomedical Sciences, Faculty of Allied Health Sciences, Thammasat University, Pathum Thani, 12120, Thailand
- Thammasat University Research Unit in Molecular Pathogenesis and Immunology of Infectious Diseases, Thammasat University, Pathum Thani, 12120, Thailand
| | - Preeyarat Malaithong
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Suthasinee Sreesai
- Central Equipment Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Wanchai Maleewong
- Mekong Health Science Research Institute, Khon Kaen University, Khon Kaen, 40002, Thailand
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Lakkhana Sadaow
- Mekong Health Science Research Institute, Khon Kaen University, Khon Kaen, 40002, Thailand
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Pongsakorn Martviset
- Department of Preclinical Science, Faculty of Medicine, Thammasat University, Pathumthani, 12120, Thailand.
- Graduate Program in Applied Biosciences, Faculty of Medicine, Thammasat University, Pathumthani, 12120, Thailand.
- Thammasat University Research Unit in Nutraceuticals and Food Safety, Thammasat University, Pathumthani, 12120, Thailand.
| | - Poom Adisakwattana
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
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3
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Ding J, Xu N, Wang J, He Y, Wang X, Liu M, Liu X. Plancitoxin-1 mediates extracellular trap evasion by the parasitic helminth Trichinella spiralis. BMC Biol 2024; 22:158. [PMID: 39075478 PMCID: PMC11287892 DOI: 10.1186/s12915-024-01958-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 07/15/2024] [Indexed: 07/31/2024] Open
Abstract
BACKGROUND Trichinella spiralis (T. spiralis) is a parasitic helminth that causes a globally prevalent neglected zoonotic disease, and worms at different developmental stages (muscle larvae, adult worms, newborn larvae) induce immune attack at different infection sites, causing serious harm to host health. Several innate immune cells release extracellular traps (ETs) to entrap and kill most pathogens that invade the body. In response, some unicellular pathogens have evolved a strategy to escape capture by ETs through the secretion of nucleases, but few related studies have investigated multicellular helminths. RESULTS In the present study, we observed that ETs from neutrophils capture adult worms of T. spiralis, while ETs from macrophages trap muscle larvae and newborn larvae, and ETs had a killing effect on parasites in vitro. To defend against this immune attack, T. spiralis secretes plancitoxin-1, a DNase II-like protein, to degrade ETs and escape capture, which is essential for the survival of T. spiralis in the host. CONCLUSIONS In summary, these findings demonstrate that T. spiralis escapes ET-mediated capture by secreting deoxyribonuclease as a potential conserved immune evasion mechanism, and plancitoxin-1 could be used as a potential vaccine candidate.
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Affiliation(s)
- Jing Ding
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Ning Xu
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Jing Wang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Yushu He
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Xuelin Wang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Mingyuan Liu
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
| | - Xiaolei Liu
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, 130062, China.
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Song YY, Zhang XZ, Wang BN, Weng MM, Zhang ZY, Guo X, Zhang X, Wang ZQ, Cui J. Molecular characterization of a novel serine proteinase from Trichinella spiralis and its participation in larval invasion of gut epithelium. PLoS Negl Trop Dis 2023; 17:e0011629. [PMID: 37695792 PMCID: PMC10513378 DOI: 10.1371/journal.pntd.0011629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 09/21/2023] [Accepted: 08/30/2023] [Indexed: 09/13/2023] Open
Abstract
BACKGROUND A novel serine proteinase of Trichinells spiralis (TsSPc) has been identified in the excretion/secretion (ES) antigens, but its role in larval invasion is unclear. The aim of this study was to clone and express TsSPc, identify its biological and biochemical characteristics, and investigate its role on larval invasion of gut epithelium during T. spiralis infection. METHODOLOGY/PRINCIPAL FINDINGS TsSPc has a functional domain of serine proteinase, and its tertiary structure consists of three amino acid residues (His88, Asp139 and Ser229) forming a pocket like functional domain. Recombinant TsSPc (rTsSPc) was expressed and purified. The rTsSPc has good immunogenicity. On Western blot analysis, rTsSPc was recognized by infection serum and anti-rTsSPc serum, natural TsSPc in crude and ES antigens was identified by anti-rTsSPc serum. The results of qPCR, Western blot and indirect immunofluorescence test (IIFT) showed that TsSPc was expressed at diverse stage worms, and mainly localized at cuticle, stichosome and intrauterine embryos of this nematode. The rTsSPc had enzymatic activity of native serine protease, which hydrolyzed the substrate BAEE, casein and collagen I. After site directed mutation of enzymatic active sites of TsSPc, its antigenicity did not change but the enzyme activity was fully lost. rTsSPc specifically bound to intestinal epithelium cells (IECs) and the binding sites were mainly localized in cell membrane and cytoplasm. rTsSPc accelerated larval invasion of IECs, whereas anti-rTsSPc antibodies and TsSPc-specific dsRNA obviously hindered larval invasion. CONCLUSIONS TsSPc was a surface and secretory proteinase of the parasite, participated in larval invasion of gut epithelium, and may be considered as a candidate vaccine target molecule against Trichinella intrusion and infection.
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Affiliation(s)
- Yan Yan Song
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, PR China
| | - Xin Zhuo Zhang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, PR China
| | - Bo Ning Wang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, PR China
| | - Min Min Weng
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, PR China
| | - Zhao Yu Zhang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, PR China
| | - Xin Guo
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, PR China
| | - Xi Zhang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, PR China
| | - Zhong Quan Wang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, PR China
| | - Jing Cui
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, PR China
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Aleem MT, Wen Z, Yu Z, Chen C, Lu M, Xu L, Song X, Li X, Yan R. Inhibition of Trichinella spiralis Membrane-Associated Progesterone Receptor (MAPR) Results in a Reduction in Worm Burden. Vaccines (Basel) 2023; 11:1437. [PMID: 37766114 PMCID: PMC10535220 DOI: 10.3390/vaccines11091437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/27/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Trichinella spiralis (T. spiralis), a nematode parasite, is the major cause of Trichinellosis, a zoonotic disease. A key role of MAPR in the reproductive system is to maintain pregnancy. Previous studies found that antihormone drug design and vaccine therapy of recombinant protein (rTs-MAPRC2) control T. spiralis infection. The current study investigates the inhibitory effects of different ratios of antibodies against Ts-MAPRC2 on the development of muscle larvae (ML) and newborn larvae (NBL). First, we performed indirect immunofluorescence assays and examined the effects of rTs-MAPRC2-Ab on ML and NBL in vitro as well as in vivo. Afterward, siRNA-Ts-MAPRC2 was transfected into T. spiralis muscle larvae. Following that, Ts-MAPRC2 protein was detected by Western Blotting, and mRNA levels were determined by qPCR. We also assessed whether siRNA-treated NBLs were infective by analyzing muscle larvae burden (MLs). Our results showed that rTs-MAPRC2-Ab greatly inhibited the activity of the Ts-MAPRC2 in ML and NBL of T. spiralis and rTs-MAPRC2-Ab reduced larval infectivity and survival in the host in a dose-dependent manner (1:50, 1:200, 1:800 dilutions). Furthermore, siRNA-Ts-MAPRC2 effectively silenced the Ts-MAPRC2 gene in muscle larvae (ML) in vitro, as well as in newborn larvae (NBL) of T. spiralis in vivo. In addition, siRNA-Ts-MAPRC2 (siRNA180, siRNA419, siRNA559) reduced host larval survival and infectivity significantly. This study, therefore, suggests that Ts-MAPRC2 might be a novel molecular target useful in the development of vaccines against T. spiralis infection.
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Affiliation(s)
- Muhammad Tahir Aleem
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (M.T.A.); (Z.W.); (C.C.); (M.L.); (L.X.); (X.S.); (X.L.)
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological, and Environmental Sciences, College of Sciences and Health Professions, Cleveland State University, Cleveland, OH 44115, USA
| | - Zhaohai Wen
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (M.T.A.); (Z.W.); (C.C.); (M.L.); (L.X.); (X.S.); (X.L.)
| | - Zhengqing Yu
- School of Agriculture, Ningxia University, Yinchuan 750021, China;
| | - Cheng Chen
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (M.T.A.); (Z.W.); (C.C.); (M.L.); (L.X.); (X.S.); (X.L.)
| | - Mingmin Lu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (M.T.A.); (Z.W.); (C.C.); (M.L.); (L.X.); (X.S.); (X.L.)
| | - Lixin Xu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (M.T.A.); (Z.W.); (C.C.); (M.L.); (L.X.); (X.S.); (X.L.)
| | - Xiaokai Song
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (M.T.A.); (Z.W.); (C.C.); (M.L.); (L.X.); (X.S.); (X.L.)
| | - Xiangrui Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (M.T.A.); (Z.W.); (C.C.); (M.L.); (L.X.); (X.S.); (X.L.)
| | - Ruofeng Yan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (M.T.A.); (Z.W.); (C.C.); (M.L.); (L.X.); (X.S.); (X.L.)
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Hamed EFA, Mostafa NES, Fawzy EM, Ibrahim MN, Ibrahim BH, Radwan M, Salama MA. Toxoplasma gondii Suppresses Th2-Induced by Trichinella spiralis Infection and Downregulates Serine Protease Genes Expression: A Critical Role in Vaccine Development. IRANIAN JOURNAL OF PARASITOLOGY 2023; 18:172-181. [PMID: 37583627 PMCID: PMC10423907 DOI: 10.18502/ijpa.v18i2.13183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 03/19/2023] [Indexed: 08/17/2023]
Abstract
Background Toxoplasma gondii coinfection can modify host immune responses and the severity and spread of other parasites. We investigated how T. gondii and Trichinella spiralis infections counter-regulate each other's immune responses. Methods The parasite burden, the expression of T. gondii rhoptry kinase ROP18 and T. spiralis putative serine protease (TsSP), the IgG1 and IgG2a responses, besides histopathological and immunohistochemical staining with iNOS and arginase were used to evaluate the dynamics of coinfection. Results Through their effects on host immune responsiveness, coinfection with T. gondii modified the virulence of T. spiralis infection. Coinfected animals with high and low doses of T. gondii demonstrated significant reductions in the T. spiralis burden of 75.2% and 68.2%, respectively. TsSP expression was downregulated in both groups by 96.2% and 86.7%, whereasROP18 expression was downregulated by only 6% and10.6%, respectively. In coinfected mice, elevated levels of T. gondii-specific IgG2a antibodies were detected. Th1 induced by T. gondii inhibits the Th2 response to T. spiralis in coinfected animals with high iNOS expression andlow-arginine1 expression. Conclusion T. gondii infection induces a shift toward a Th1-type immune response while suppressing a helminth-specific Th2 immune response, paving the way for developing novel vaccines and more efficient control strategies.
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Affiliation(s)
| | - Nahed El-Sayed Mostafa
- Department of Medical Parasitology, Faculty of Medicine, Zagazig University, Sharkia, Egypt
| | - Eman Magdy Fawzy
- Department of Medical Parasitology, Faculty of Medicine, Zagazig University, Sharkia, Egypt
| | - Mohamed Nabil Ibrahim
- Department of Clinical Laboratories, College of Applied Medical Sciences, Jouf University, Qurrayat, KSA
| | - Basma Hamed Ibrahim
- Department of Pathology, Faculty of Medicine, Zagazig University, Sharkia, Egypt
| | - Mona Radwan
- Department of Community and Occupational Medicine, Faculty of medicine, Zagazig University, Sharkia, Egypt
| | - Marwa Ahmed Salama
- Department of Medical Parasitology, Faculty of Medicine, Zagazig University, Sharkia, Egypt
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Hou J, Meng S, Zhang B, Ruan R, Zhang Y, Wang Z, Song M, Bai Z. Effect of RNA interference with glutamate decarboxylase on acid resistance of Trichinella spiralis. Acta Trop 2023; 241:106869. [PMID: 36849092 DOI: 10.1016/j.actatropica.2023.106869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/24/2023] [Accepted: 02/18/2023] [Indexed: 02/27/2023]
Abstract
Trichinella spiralis is a zoonotic parasite that infects most mammals, even humans. Glutamate decarboxylase (GAD) is an important enzyme in glutamate-dependent acid resistance system 2 (AR2), but the GAD of T. spiralis in AR2 is unclear. We aimed to investigate the role of T. spiralis glutamate decarboxylase (TsGAD) in AR2. We silenced the TsGAD gene to evaluate the AR of T. spiralis muscle larvae (ML) in vivo and in vitro via siRNA. The results showed that recombinant TsGAD was recognized by anti-rTsGAD polyclonal antibody (57 kDa), and qPCR indicated that TsGAD transcription peaked at pH 2.5 for 1 h compared to that with pH 6.6 phosphate-buffered saline. Indirect immunofluorescence assays revealed that TsGAD was expressed in the epidermis of ML. After TsGAD silencing in vitro, TsGAD transcription and the survival rate of ML decreased by 15.2% and 17%, respectively, compared with those of the PBS group. Both TsGAD enzymatic activity and the acid adjustment of siRNA1-silenced ML were weakened. In vivo, each mouse was orally infected with 300 siRNA1-silenced ML. On days 7 and 42 post-infection, the reduction rates of adult worms and ML were 31.5% and 49.05%, respectively. Additionally, the reproductive capacity index and larvae per gram of ML were 62.51±7.32 and 1250.22±146.48, respectively, lower than those of the PBS group. Haematoxylin-eosin staining revealed many inflammatory cells infiltrating the nurse cells in the diaphragm of mice infected with siRNA1-silenced ML. The survival rate of the F1 generation ML was 27% higher than that of the F0 generation ML, but there was no difference from the PBS group. These results first indicated that GAD plays a crucial role in AR2 of T. spiralis. TsGAD gene silencing reduced the worm burden in mice, providing data for the comprehensive study of the AR system of T. spiralis and a new idea for the prevention of trichinosis.
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Affiliation(s)
- Jiaming Hou
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Shi Meng
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Bohan Zhang
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Rulin Ruan
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Yan Zhang
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Ze Wang
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Mingxin Song
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China.
| | - Zhikun Bai
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China.
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Kobpornchai P, Reamtong O, Phuphisut O, Malaitong P, Adisakwattana P. Serine protease inhibitor derived from Trichinella spiralis (TsSERP) inhibits neutrophil elastase and impairs human neutrophil functions. Front Cell Infect Microbiol 2022; 12:919835. [PMID: 36389172 PMCID: PMC9640929 DOI: 10.3389/fcimb.2022.919835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 09/14/2022] [Indexed: 11/29/2022] Open
Abstract
During early infection with Trichinella spiralis, host neutrophils destroy newborn larvae migrating in the bloodstream, preventing infection. However, parasites secrete various immunomodulatory molecules to escape the host’s defense mechanisms, allowing them to infect the host and live for long periods. T. spiralis secretes serine protease inhibitors (TsSERPs), which are key inhibitory molecules that regulate serine proteases involved in digestion and inflammation. However, the modulatory roles of TsSERP in the inhibition of neutrophil serine proteases (NSPs) and neutrophil functions are unknown. Therefore, the immunomodulatory properties of recombinant TsSERP1 (rTsSERP1) on NSPs and neutrophil functions were investigated in this study. rTsSERP1 preferentially inhibited human neutrophil elastase (hNE). In addition, incubation of rTsSERP1 with fMLP-induced neutrophils impaired their phagocytic ability. The formation of neutrophil extracellular traps (NETs) was activated with phorbol myristate acetate (PMA), and NETs were dramatically reduced when treated with rTsSERP1. Furthermore, rTsSERP1 suppressed the production of proinflammatory cytokines and chemokines during neutrophil activation, which are essential for neutrophil-mediated local or systemic inflammation regulation. In conclusion, T. spiralis immune evasion mechanisms are promoted by the inhibitory properties of TsSERP1 against neutrophil elastase and neutrophil defense functions, and these might be promising alternative treatment targets for inflammatory disorders.
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Affiliation(s)
- Porntida Kobpornchai
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Onrapak Reamtong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Orawan Phuphisut
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Preeyarat Malaitong
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Poom Adisakwattana
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- *Correspondence: Poom Adisakwattana,
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Xu J, Pang Z, Zhang J, Xia S, Wang R, Zhang Y, Zhen J, Song X, Lin L, Sun F, Xuan X, Lu Y. Regulatory effects of Trichinella spiralis and a serine protease inhibitor on the endoplasmic reticulum stress response of intestinal epithelial cells. Vet Res 2022; 53:18. [PMID: 35241168 PMCID: PMC8892742 DOI: 10.1186/s13567-022-01036-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/31/2022] [Indexed: 11/15/2022] Open
Abstract
The accumulation of unfolded or misfolded proteins in the endoplasmic reticulum can cause an endoplasmic reticulum stress (ERS) response. If ERS continues or cannot be alleviated, it will cause the production of proapoptotic factors and eventually lead to apoptosis. Therefore, this study mainly explored whether Trichinella spiralis Kazal-type serine protease inhibitor (TsKaSPI) contributed to the invasion of intestinal epithelial cells during the infectious stage of T. spiralis by regulating ERS. First, in the T. spiralis infection model, H&E staining was used to analyse the damage to jejunum tissue, a TUNEL assay was used to examine cell apoptosis, and the expression of ERS-related and apoptosis-related molecules was also measured. The results showed that ERS occurred during the intestinal phase of T. spiralis infection, while remission began during the cyclic phase. Then, we selected TsKaSPI, one of the important components of T. spiralis ES antigens, for in vitro experiments. The results showed that TsKaSPI could induce apoptosis in a porcine small intestinal epithelial cell line (IPEC cells) by activating ERS and promote activation of the NF-κB signalling pathway. Inhibition experiments confirmed that the occurrence of ERS was accompanied by the activation of NF-κB, and the two processes regulated each other. Finally, we conducted in vivo experiments and administered TsKaSPI to mice. The results confirmed that TsKaSPI could activate ERS and lead to apoptosis in intestinal epithelial cells. In conclusion, T. spiralis infection and TsKaSPI can promote cell apoptosis by activating the ERS response in intestinal epithelial cells and activate the NF-κB signalling pathway to promote the occurrence and development of inflammation.
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Affiliation(s)
- Jingyun Xu
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
- College of Veterinary Medicine, Sichuan Agricultural University, 211 Huimin Street, Chengdu, 611130, China
| | - Zixuan Pang
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Jinpeng Zhang
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Shuang Xia
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Ruibiao Wang
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Yuheng Zhang
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Jingbo Zhen
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Xuewei Song
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Lihao Lin
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Feng Sun
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Xinxin Xuan
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Yixin Lu
- Heilongjiang Provincial Key Laboratory of Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China.
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10
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Ren HN, Bai SJ, Wang Z, Han LL, Yan SW, Jiang P, Zhang X, Wang ZQ, Cui J. A metalloproteinase Tsdpy31 from Trichinella spiralis participates in larval molting and development. Int J Biol Macromol 2021; 192:883-894. [PMID: 34656542 DOI: 10.1016/j.ijbiomac.2021.10.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 08/20/2021] [Accepted: 10/04/2021] [Indexed: 01/07/2023]
Abstract
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.
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Affiliation(s)
- Hua Nan Ren
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, PR China
| | - Sheng Jie Bai
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, PR China
| | - Zhen Wang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, PR China
| | - Lu Lu Han
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, PR China
| | - Shu Wei Yan
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, PR China
| | - Peng Jiang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, PR China
| | - Xi Zhang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, PR China
| | - Zhong Quan Wang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, PR China.
| | - Jing Cui
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, PR China.
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11
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Bai Y, Ma KN, Sun XY, Dan Liu R, Long SR, Jiang P, Wang ZQ, Cui J. Molecular characterization of a novel cathepsin L from Trichinella spiralis and its participation in invasion, development and reproduction. Acta Trop 2021; 224:106112. [PMID: 34453915 DOI: 10.1016/j.actatropica.2021.106112] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/09/2021] [Accepted: 08/13/2021] [Indexed: 12/14/2022]
Abstract
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.
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12
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Zhuo TX, Wang Z, Song YY, Yan SW, Liu RD, Zhang X, Wang ZQ, Cui J. Characterization of a Novel Glutamine Synthetase From Trichinella spiralis and Its Participation in Larval Acid Resistance, Molting, and Development. Front Cell Dev Biol 2021; 9:729402. [PMID: 34616735 PMCID: PMC8488193 DOI: 10.3389/fcell.2021.729402] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 08/24/2021] [Indexed: 12/29/2022] Open
Abstract
Trichinella spiralis is a major foodborne parasite worldwide. After the encapsulated muscle larvae (ML) in meat are ingested, the ML are liberated in the stomach of the host and activated into intestinal infectious larvae (IIL), which develop into adult worm after molting four times. A novel glutamine synthetase (TsGS) was identified from T. spiralis IIL at 10 h post-infection, but its biological role in T. spiralis life cycle is not clear. The aim of this study was to investigate the biological characteristics of TsGS and its functions in larval acid resistance, molting, and development. TsGS has a glutamine synthetase (GS) catalytic domain. Complete TsGS sequence was cloned and expressed in Escherichia coli BL21. rTsGS has good immunogenicity. qPCR and Western blotting showed that TsGS was highly expressed at IIL stage, and immunofluorescence revealed that TsGS was principally localized at the cuticle and intrauterine embryos of this nematode. rTsGS has enzymatic activity of natural GS to hydrolyze the substrate (Glu, ATP, and NH4+). Silencing of TsGS gene significantly reduced the IIL survival at pH 2.5, decreased the IIL burden, and impeded larval molting and development. The results demonstrated that TsGS participates in T. spiralis larval acid resistance, molting and development, and it might be a candidate vaccine target against Trichinella molting and development.
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Affiliation(s)
- Tong Xu Zhuo
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, China
| | - Zhen Wang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, China
| | - Yan Yan Song
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, China
| | - Shu Wei Yan
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, China
| | - Ruo Dan Liu
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, China
| | - Xi Zhang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, China
| | - Zhong Quan Wang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, China
| | - Jing Cui
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, China
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13
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Hu YY, Zhang R, Yan SW, Yue WW, Zhang JH, Liu RD, Long SR, Cui J, Wang ZQ. Characterization of a novel cysteine protease in Trichinella spiralis and its role in larval intrusion, development and fecundity. Vet Res 2021; 52:113. [PMID: 34446106 PMCID: PMC8390047 DOI: 10.1186/s13567-021-00983-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 07/06/2021] [Indexed: 12/29/2022] Open
Abstract
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.
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Affiliation(s)
- Yuan Yuan Hu
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, 450052, China
| | - Ru Zhang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, 450052, China
| | - Shu Wei Yan
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, 450052, China
| | - Wen Wen Yue
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, 450052, China
| | - Jia Hang Zhang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, 450052, China
| | - Ruo Dan Liu
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, 450052, China
| | - Shao Rong Long
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, 450052, China
| | - Jing Cui
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, 450052, China.
| | - Zhong Quan Wang
- Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, 450052, China.
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14
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Gao Y, Meng X, Yang X, Meng S, Han C, Li X, Wang S, Li W, Song M. RNAi-mediated silencing of Trichinella spiralis glutaminase results in reduced muscle larval infectivity. Vet Res 2021; 52:51. [PMID: 33766101 PMCID: PMC7992778 DOI: 10.1186/s13567-021-00921-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/23/2021] [Indexed: 12/18/2022] Open
Abstract
Trichinella spiralis is an important foodborne parasitic nematode distributed worldwide that infects humans and animals. Glutaminase (GLS) is an important gene in the glutamine-dependent acid resistance (AR) system; however, its role in T. spiralis muscle larvae (ML) remains unclear. The present study aimed to characterize T. spiralis GLS (TsGLS) and assess its function in T. spiralis ML AR both in vitro and in vivo using RNA interference. The results indicated that native TsGLS (72 kDa) was recognized by anti-rTsGLS serum at the muscle larvae stage; moreover, an immunofluorescence assay confirmed that TsGLS was located in the epidermis of ML. After silencing the TsGLS gene, the relative expression of TsGLS mRNA and the survival rate of T. spiralis ML were reduced by 60.11% and 16.55%, respectively, compared to those in the PBS and control groups. In vivo AR assays revealed that the worm numbers at 7 and 35 days post-infection (dpi) decreased by 61.64% and 66.71%, respectively, compared to those in the PBS group. The relative expression of TsGLS mRNA in F1 generation T. spiralis ML was reduced by 42.52%, compared to that in the PBS group. To the best of our knowledge, this is the first study to report the presence of the glutamine-dependent AR system in T. spiralis. Our results indicate that TsGLS plays a crucial role in the T. spiralis AR system; thus, it could be used as a potential candidate target molecule for producing vaccines against T. spiralis infection.
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Affiliation(s)
- Yuan Gao
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Xiaoqing Meng
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Xiao Yang
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Shi Meng
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Caixia Han
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Xiaoyun Li
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Shuang Wang
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China
| | - Wei Li
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China.
| | - Mingxin Song
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, 600 Changjiang Street, Harbin, 150030, China.
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