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Park S, Cho E, Senevirathne A, Chung HJ, Ha S, Kim CH, Kang S, Lee JH. Salmonella vector induces protective immunity against Lawsonia and Salmonella in murine model using prokaryotic expression system. J Vet Sci 2024; 25:e4. [PMID: 38311319 PMCID: PMC10839175 DOI: 10.4142/jvs.23219] [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: 08/27/2023] [Revised: 11/18/2023] [Accepted: 11/24/2023] [Indexed: 02/07/2024] Open
Abstract
BACKGROUND Lawsonia intracellularis is the causative agent of proliferative enteropathy and is associated with several outbreaks, causing substantial economic loss to the porcine industry. OBJECTIVES In this study, we focused on demonstrating the protective effect in the mouse model through the immunological bases of two vaccine strains against porcine proliferative enteritis. METHODS We used live-attenuated Salmonella Typhimurium (ST) secreting two selected immunogenic LI antigens (Lawsonia autotransporter A epitopes and flagellin [FliC]-peptidoglycan-associated lipoprotein-FliC) as the vaccine carrier. The constructs were cloned into a Salmonella expression vector (pJHL65) and transformed into the ST strain (JOL912). The expression of immunogenic proteins within Salmonella was evaluated via immunoblotting. RESULTS Immunizing BALB/c mice orally and subcutaneously induced high levels of LI-specific systemic immunoglobulin G and mucosal secretory immunoglobulin A. In immunized mice, there was significant upregulation of interferon-γ and interleukin-4 cytokine mRNA and an increase in the subpopulations of cluster of differentiation (CD) 4+ and CD 8+ T lymphocytes upon splenocytes re-stimulation with LI antigens. We observed significant protection in C57BL/6 mice against challenge with 106.9 times the median tissue culture infectious dose of LI or 2 × 109 colony-forming units of the virulent ST strain. Immunizing mice with either individual vaccine strains or co-mixture inhibited bacterial proliferation, with a marked reduction in the percentage of mice shedding Lawsonia in their feces. CONCLUSIONS Salmonella-mediated LI gene delivery induces robust humoral and cellular immune reactions, leading to significant protection against LI and salmonellosis.
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Affiliation(s)
- Sungwoo Park
- College of Veterinary Medicine, Jeonbuk National University, Iksan Campus, Iksan 54596, Korea
- Swine Science Division, National Institute of Animal Science, Cheonan 31000, Korea
| | - Eunseok Cho
- Swine Science Division, National Institute of Animal Science, Cheonan 31000, Korea
| | - Amal Senevirathne
- College of Veterinary Medicine, Jeonbuk National University, Iksan Campus, Iksan 54596, Korea
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Hak-Jae Chung
- Swine Science Division, National Institute of Animal Science, Cheonan 31000, Korea
| | - Seungmin Ha
- Dairy Science Division, National Institute of Animal Science, Cheonan 31000, Korea
| | - Chae-Hyun Kim
- Swine Science Division, National Institute of Animal Science, Cheonan 31000, Korea
| | - Seogjin Kang
- Dairy Science Division, National Institute of Animal Science, Cheonan 31000, Korea.
| | - John Hwa Lee
- College of Veterinary Medicine, Jeonbuk National University, Iksan Campus, Iksan 54596, Korea.
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Hidalgo-Gajardo A, Gutiérrez N, Lamazares E, Espinoza F, Escobar-Riquelme F, Leiva MJ, Villavicencio C, Mena-Ulecia K, Montesino R, Altamirano C, Sánchez O, Rivas CI, Ruíz Á, Toledo JR. Co-Formulation of Recombinant Porcine IL-18 Enhances the Onset of Immune Response in a New Lawsonia intracellularis Vaccine. Vaccines (Basel) 2023; 11:1788. [PMID: 38140192 PMCID: PMC10747595 DOI: 10.3390/vaccines11121788] [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: 10/17/2023] [Revised: 11/20/2023] [Accepted: 11/25/2023] [Indexed: 12/24/2023] Open
Abstract
Pig is one of the most consumed meats worldwide. One of the main conditions for pig production is Porcine Enteropathy caused by Lawsonia intracellularis. Among the effects of this disease is chronic mild diarrhea, which affects the weight gain of pigs, generating economic losses. Vaccines available to prevent this condition do not have the desired effect, but this limitation can be overcome using adjuvants. Pro-inflammatory cytokines, such as interleukin 18 (IL-18), can improve an immune response, reducing the immune window of protection. In this study, recombinant porcine IL-18 was produced and expressed in Escherichia coli and Pichia pastoris. The protein's biological activity was assessed in vitro and in vivo, and we determined that the P. pastoris protein had better immunostimulatory activity. A vaccine candidate against L. intracellularis, formulated with and without IL-18, was used to determine the pigs' cellular and humoral immune responses. Animals injected with the candidate vaccine co-formulated with IL-18 showed a significant increase of Th1 immune response markers and an earlier increase of antibodies than those vaccinated without the cytokine. This suggests that IL-18 acts as an immunostimulant and vaccine adjuvant to boost the immune response against the antigens, reducing the therapeutic window of recombinant protein-based vaccines.
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Affiliation(s)
- Angela Hidalgo-Gajardo
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, VIII Región, Concepción 4070386, Chile; (A.H.-G.); (M.J.L.); (C.V.); (C.I.R.)
- Centro de Desarrollo e Innovación Biovacuvet SpA, VIII Región, Concepción 4090838, Chile
| | - Nicolás Gutiérrez
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, VIII Región, Concepción 4070386, Chile; (A.H.-G.); (M.J.L.); (C.V.); (C.I.R.)
- Centro de Desarrollo e Innovación Biovacuvet SpA, VIII Región, Concepción 4090838, Chile
| | - Emilio Lamazares
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, VIII Región, Concepción 4070386, Chile; (A.H.-G.); (M.J.L.); (C.V.); (C.I.R.)
| | - Felipe Espinoza
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, VIII Región, Concepción 4070386, Chile; (A.H.-G.); (M.J.L.); (C.V.); (C.I.R.)
- Centro de Desarrollo e Innovación Biovacuvet SpA, VIII Región, Concepción 4090838, Chile
| | - Fernanda Escobar-Riquelme
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, VIII Región, Concepción 4070386, Chile; (A.H.-G.); (M.J.L.); (C.V.); (C.I.R.)
| | - María J. Leiva
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, VIII Región, Concepción 4070386, Chile; (A.H.-G.); (M.J.L.); (C.V.); (C.I.R.)
| | - Carla Villavicencio
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, VIII Región, Concepción 4070386, Chile; (A.H.-G.); (M.J.L.); (C.V.); (C.I.R.)
| | - Karel Mena-Ulecia
- Departamento de Ciencias Biológicas y Químicas, Facultad de Recursos Naturales, Universidad Católica de Temuco, IX Región, Temuco 4813302, Chile;
| | - Raquel Montesino
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, VIII Región, Concepción 4070386, Chile; (A.H.-G.); (M.J.L.); (C.V.); (C.I.R.)
| | - Claudia Altamirano
- Laboratorio de Cultivos Celulares, Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, V Región, Valparaíso 2362803, Chile;
| | - Oliberto Sánchez
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, VIII Región, Concepción 4070386, Chile; (A.H.-G.); (M.J.L.); (C.V.); (C.I.R.)
| | - Coralia I. Rivas
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, VIII Región, Concepción 4070386, Chile; (A.H.-G.); (M.J.L.); (C.V.); (C.I.R.)
| | - Álvaro Ruíz
- Departamento de Patología y Medicina Preventiva, Facultad de Ciencias Veterinarias, Universidad de Concepción, XVI Región, Chillán 3812120, Chile;
| | - Jorge R. Toledo
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, VIII Región, Concepción 4070386, Chile; (A.H.-G.); (M.J.L.); (C.V.); (C.I.R.)
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Xu T, Guo Y, Zhang Y, Cao K, Zhou X, Qian M, Han X. Alleviative Effect of Probiotic Ferment on Lawsonia intracellularis Infection in Piglets. BIOLOGY 2023; 12:879. [PMID: 37372164 DOI: 10.3390/biology12060879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/10/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023]
Abstract
(1) Background: Lawsonia intracellularis (LI) is an obligate intracellular Gram-negative bacterium that causes porcine ileitis. Pigs infected with LI have severe ileal lesions and show symptoms of diarrhea, indigestion, and growth retardation. Previous studies found that probiotic ferment (FAM) improved the growth performance, gut barrier, and function in piglets. Therefore, we aimed to reveal the mechanism that FAM alleviates negative performance in LI-challenged piglets by characterizing the changes in intestinal integrity, function, and gut microbiota following FAM supplementation. (2) Methods: Twenty-four healthy piglets were randomly allotted to four treatments. Three groups were challenged with LI; both FAM addition and vaccination were performed to explore their positive effects on LI-infected piglets. (3) Results: Piglets infected with LI showed lower growth performance and typical pathological symptoms. Moreover, microscopic images showed that observed intestinal morphological damage could be repaired by FAM and vaccine. To explore the digestion of nutrients in piglets, both digestive enzyme activity and ileal transporter expression were performed to reveal the promoting effect of additives. Reduction of LI colonization intervention by FAM could also ameliorate abnormal differentiation and function of intestinal epithelial cells and alleviate severe inflammatory responses in piglets. Regarding the gut microbiota, both the structure and function of the ileal and colonic microbiota were altered following FAM supplementation. (4) Conclusions: In conclusion, probiotic ferment can reduce the colonization of LI in the ileum, improve intestinal damage, barrier function and microbiota structure, and enhance digestive enzyme activity and nutrient transport proteins expression, thereby improving piglet growth performance, which has the effect of preventing ileitis in pigs.
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Affiliation(s)
- Tingting Xu
- Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, China
- Key Laboratory of Animal Nutrition and Feed Science in East China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yong Guo
- Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agricultural Sciences, College of Animal Science and Technology, Hangzhou 310022, China
| | - Yuanyuan Zhang
- Key Laboratory of Animal Nutrition and Feed Science in East China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Kai Cao
- Key Laboratory of Animal Nutrition and Feed Science in East China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xinchen Zhou
- Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, China
- Key Laboratory of Animal Nutrition and Feed Science in East China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Mengqi Qian
- Key Laboratory of Animal Nutrition and Feed Science in East China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xinyan Han
- Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, China
- Key Laboratory of Animal Nutrition and Feed Science in East China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
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Yao S, Yang X, Wu W, Jiang Q, Deng S, Zheng B, Chen L, Chen Y, Xiang X. Effect of Paecilomyces cicadae polysaccharide Pc0-1 on cyclophosphamide-induced immunosuppression and regulation of intestinal flora in mice. FOOD BIOSCI 2022. [DOI: 10.1016/j.fbio.2022.102340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Hankel J, Sander S, Muthukumarasamy U, Strowig T, Kamphues J, Jung K, Visscher C. Microbiota of vaccinated and non-vaccinated clinically inconspicuous and conspicuous piglets under natural Lawsonia intracellularis infection. Front Vet Sci 2022; 9:1004506. [DOI: 10.3389/fvets.2022.1004506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 10/03/2022] [Indexed: 11/13/2022] Open
Abstract
Lawsonia (L.) intracellularis is a widespread, economically important bacterium causing the porcine proliferative enteropathy (PPE). In this study, we evaluated intestinal microbiota of naturally exposed L. intracellularis-positive pigs under standardized conditions. To obtain three independent repetitions, 27 L. intracellularis-infected pigs (19.0 ± 1.50 kg body weight) from one farm were divided into three groups at an age of 7 to 8 weeks (nine pigs/group). Pigs were either vaccinated against L. intracellularis via oral drenching on their 21st day of life (attenuated live vaccine) or non-vaccinated and selected according to clinical findings (pigs without deviating fecal consistency or with moderate to soft fecal consistency). Comparison of the clinically inconspicuous piglets that differed regarding their vaccination status showed fewer significant differences in fecal microbiota composition. The vaccination led to an overall enrichment of bacterial species belonging to the order Clostridiales, while species of the genus Collinsella and Prevotella were decreased. Several bacterial species belonging to the order Bacteroidales, mainly of the family Prevotellacecae, often closely matching Prevotella copri differed significantly between non-vaccinated clinically inconspicuous and conspicuous piglets. Whether those bacterial species play a role in mitigating the severity of an L. intracellularis infection remains to be defined.
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Hansen MS, Jensen TK, Hjulsager CK, Angen Ø, Riber U, Nielsen J, Heegaard PMH, Larsen LE. Experimental infection of high health pigs with porcine circovirus type 2 (PCV2) and Lawsonia intracellularis. Front Vet Sci 2022; 9:994147. [PMID: 36277064 PMCID: PMC9583870 DOI: 10.3389/fvets.2022.994147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 09/09/2022] [Indexed: 11/04/2022] Open
Abstract
Background Porcine circovirus type 2 (PCV2) and Lawsonia intracellularis infections can cause enteritis in pigs. A Danish study showed a significantly higher probability of detecting PCV2 without concurrent L. intracellularis infection, indicating that one of these pathogens has an impact on the dynamics of the other. Therefore, a delayed co-infection model was set up, initially aiming at investigating the interaction between PCV2 and L. intracellularis in pigs challenged with PCV2 and 2 weeks later with L. intracellularis. But due to PCV2 contamination of the L. intracellularis inoculum the aim was revisited to describing the infection dynamics and pathogenesis of pigs infected with PCV2 followed by delayed simultaneous exposure to PCV2 and L. intracellularis. Twenty-four high-health piglets were divided into three groups of eight pigs (A, B, C) and inoculated at experimental day (EXD) 0 with mock (groups A and B) or PCV2 (group C), and at EXD 14 with mock (group A) or L. intracellularis/PCV2 (groups B and C). The pigs underwent daily clinical examination, and were necropsied at EXD 51–52. Furthermore, histology, immunohistochemistry, serology and PCR for PCV2 and L. intracellularis, and measurement of C-reactive protein were carried out. Results Group A remained negative for PCV2 and L. intracellularis. Following inoculation with L. intracellularis/PCV2, no significant differences were observed between group B and C, however pigs already infected with PCV2 (group C) showed milder clinical signs and exhibited milder intestinal lesions, less shedding of L. intracellularis and developed higher L. intracellularis antibody titers than the pigs in group B that only received the combined infection. Though the differences between group B and C were non-significant, all results pointed in the same direction, indicating that the pigs in group B were more affected by the L. intracellularis infection compared to the pigs in group C. Conclusions Previous exposure to PCV2 had limited impact on the subsequent exposure to a combined L. intracellularis/PCV2 inoculation. However, there was a tendency that the infection dynamics of PCV2 and development of antibodies to PCV2 and L. intracellularis were altered in pigs previously exposed to PCV2. These differences should be confirmed in further experimental trials.
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Affiliation(s)
- Mette S. Hansen
- Center for Diagnostic, Technical University of Denmark (DTU), Kgs. Lyngby, Denmark,The National Veterinary Institute, DTU, Kalvehave, Denmark,Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark,*Correspondence: Mette S. Hansen
| | - Tim K. Jensen
- Center for Diagnostic, Technical University of Denmark (DTU), Kgs. Lyngby, Denmark
| | - Charlotte K. Hjulsager
- Center for Diagnostic, Technical University of Denmark (DTU), Kgs. Lyngby, Denmark,Statens Serum Institut, Copenhagen, Denmark
| | - Øystein Angen
- Statens Serum Institut, Copenhagen, Denmark,The National Veterinary Institute, DTU, Frederiksberg, Denmark
| | - Ulla Riber
- Center for Diagnostic, Technical University of Denmark (DTU), Kgs. Lyngby, Denmark
| | - Jens Nielsen
- The National Veterinary Institute, DTU, Kalvehave, Denmark,National Institute of Aquatic Resources, DTU, Kgs. Lyngby, Denmark
| | - Peter M. H. Heegaard
- Center for Diagnostic, Technical University of Denmark (DTU), Kgs. Lyngby, Denmark,Experimental and Translational Immunology, Department of Health Technology, DTU, Kgs. Lyngby, Denmark
| | - Lars E. Larsen
- Center for Diagnostic, Technical University of Denmark (DTU), Kgs. Lyngby, Denmark,Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
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Won G, Chi NK, Park Y. The Effectiveness of Commercial Vaccination against Lawsonia intracellularis in Mitigating the Reduction in ADWG, the Increased Mortality and Fecal Shedding of the Vaccinated Pigs: A Systematic Review and Meta-Analysis. Vet Sci 2022; 9:536. [PMID: 36288149 PMCID: PMC9607650 DOI: 10.3390/vetsci9100536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 09/08/2022] [Accepted: 09/21/2022] [Indexed: 11/16/2022] Open
Abstract
In this study, a systematic review and meta-analysis was conducted to assess the efficacy of commercial vaccines against PPE in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Of the 373 articles reviewed, 16 fulfilled the pre-specified inclusion criteria. Three independent reviewers extracted the data, and vaccine effectiveness was assessed using the outcomes of interest. The majority of studies had a low or unclear risk of bias as assessed using the ARRIVE guidelines. The results of the meta-analysis indicated that the vaccination resulted in statistically significant reductions in bacterial fecal shedding (odds ratio, OR = 0.122, 95% confidence interval, CI 0.054−0.278) and mortality rate (risk ratio, RR = 0.199; 95% CI, 0.066−0.605). Furthermore, ADWG was significantly increased in the vaccinated pigs compared to the unvaccinated controls (standardized mean difference (SMD) = 0.606, 95% CI 0.243−0.969). In the subgroup analysis, the production phase and study type significantly influenced the effect size (p < 0.1). The Egger’s regression test showed no evidence of publication bias (p > 0.1). The effectiveness of commercially available vaccines against PPE-related weight loss, fecal shedding, and mortality suggests that the vaccines may help control PPE on affected swine farms.
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Affiliation(s)
- Gayeon Won
- College of Veterinary Medicine, Jeonbuk National University, Iksan Campus, Gobong-ro 79, Iksan 54596, Korea
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Two-Dimensional Electrophoresis Coupled with Western Blot as a Method to Detect Potential Neutralizing Antibody Targets from Gram-Negative Intracellular Bacteria. Methods Mol Biol 2021. [PMID: 34784032 DOI: 10.1007/978-1-0716-1900-1_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Antigen selection is a critical step in subunit vaccine design, especially if the goal is to identify antigens that can be bound by neutralizing antibodies to prevent invasion of cells by intracellular bacteria. Here, we describe a method involving two dimensional gel electrophoresis (2-DE) coupled with western blotting (WB) and mass spectrometry (MS) to identify bacterial proteins that: (1) interact with the host target cell proteins, and (2) are targeted by antibodies from sera from infected animals. Subsequent steps would be performed to validate that the bacteria are targeted by neutralizing antibodies to prevent invasion of the eukaryotic cells.
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Li M, Xiao N, Li J, Lin H, Fan H. Evaluation of immune efficacy of Omp2 protein against Lawsonia intracellularis in mice. Vet Microbiol 2021; 263:109274. [PMID: 34781192 DOI: 10.1016/j.vetmic.2021.109274] [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: 04/14/2021] [Revised: 08/31/2021] [Accepted: 10/29/2021] [Indexed: 11/16/2022]
Abstract
Porcine proliferative enteropathy (PPE) is caused by the obligate intracellular bacterium Lawsonia intracellularis. Infection results in an enteric disease characterised by decreased growth performance of pigs, and presents a major economic burden for swine industries worldwide. Since vaccination is an effective technique for controlling PPE, novel effective vaccine platforms are need to be developed. In this study, five proteins of L. intracellularis were screened through animal experiments and the highly immunoprotective Omp2 protein was identified. Then, the immune efficacy of Omp2 was further evaluated based on humoral and cell mediated immune (CMI) responses, faecal bacterial shedding, histopathological lesions, immune barrier function of intestinal mucosa as well as digestive and absorptive capacity following challenge of mice with L. intracellularis. Mice immunised with Omp2 had reduced faecal shedding, fewer histopathological lesions and reduced bacteria colonisation of the ileum. Additionally, Omp2 immunised mice showed stronger serum IgG and IFN-γ levels, up-regulated Occludin and zonula occludens-1 (ZO-1) mRNA levels, as well as increased numbers of intestinal intraepithelial lymphocytes (IELs) and levels of sIgA. On the contrary, the activities of LPS, α-AMS and AKP were significantly increased. Our investigation indicated that immunization with Omp2 reduced the severity of clinical signs and provided efficacious immunoprotection for target animals against L. intracellularis infection in mouse model.
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Affiliation(s)
- Minxue Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ning Xiao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jiannan Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Huixing Lin
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hongjie Fan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, China.
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Campillo M, Smith SH, Gally DL, Opriessnig T. Review of methods for the detection of Lawsonia intracellularis infection in pigs. J Vet Diagn Invest 2021; 33:621-631. [PMID: 33739176 PMCID: PMC8225690 DOI: 10.1177/10406387211003551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Lawsonia intracellularis is an obligate intracellular bacterium
associated with enteric disease in pigs. Clinical signs include weight loss,
diarrhea, and, in some cases, sudden death. The hallmark lesion is the
thickening of the intestinal mucosa caused by increased epithelial cell
replication, known as proliferative enteropathy. The immune response to
L. intracellularis is not well defined, and detection of
the infection, especially in the early stages, is still a significant challenge.
We review here the main approaches used to identify this important but poorly
understood pathogen. Detection of L. intracellularis infection
as the cause of clinical disease is confounded by the high prevalence of the
pathogen in many countries and that several other pathogens can produce similar
clinical signs. A single L. intracellularis–specific ELISA and
several amplification assays are available commercially to aid detection and
surveillance, although histopathology remains the primary way to reach a
conclusive diagnosis. There are major gaps in our understanding of L.
intracellularis pathogenesis, especially how the host responds to
infection and the factors that drive infection toward different clinical
outcomes. Knowledge of pathogenesis will increase the predictive value of
antemortem tests to guide appropriate interventions, including identification
and treatment of subclinically affected pigs in the early stages of disease,
given that this important manifestation reduces pig productivity and contributes
to the economic burden of L. intracellularis worldwide.
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Affiliation(s)
- Marta Campillo
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Sionagh H Smith
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - David L Gally
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Tanja Opriessnig
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
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