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Cheng TY, Campler MR, Schroeder DC, Yang M, Mor SK, Ferreira JB, Arruda AG. Detection of Multiple Lineages of PRRSV in Breeding and Growing Swine Farms. Front Vet Sci 2022; 9:884733. [PMID: 35774978 PMCID: PMC9237545 DOI: 10.3389/fvets.2022.884733] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
The detection and co-circulation of multiple variants of porcine reproductive and respiratory syndrome virus (PRRSV) have been observed and reported in swine. However, the potential long-term impact of multiple prevailing PRRSV variants on pig-performance is not yet fully understood. The primary objective of this study was to describe the genetic variation of PRRSV in processing fluid (PF), oral fluid (OF), and tonsil scraping (TS) specimens from five swine farms with different production types and PRRS status over a period of time (~1 year). Furthermore, the association between PRRSV prevalence and production parameters was investigated. Results showed that PRRSV was detected by RT-qPCR in 21–25% of all types of specimens. In breeding farms, PRRSV detection in PF and/or TS samples was correlated with stillborn and mummified fetuses, and pre-weaning mortality throughout the study period. Although ORF5 sequences were obtained in <16% of all sample types, simultaneous detection of PRRSV variants including field and vaccine strains within a single sampling event was identified in both breeding and growing pig farms. Phylogenetic analyses based on the ORF5 sequence classified the detected field PRRSV into L1A and L1H, two sub-lineages of lineage 1 (L1). Our study demonstrated the presence of multiple PRRSV lineages, sub-lineages, and variants in swine herds and its potential association with swine reproductive performance under field conditions.
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Affiliation(s)
- Ting-Yu Cheng
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
| | - Magnus R. Campler
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
| | - Declan C. Schroeder
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, United States
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - My Yang
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, United States
| | - Sunil K. Mor
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN, United States
| | - Juliana B. Ferreira
- Department of Population Health & Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Andréia G. Arruda
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States
- *Correspondence: Andréia G. Arruda
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Maragkakis G, Korou LM, Chaintoutis SC, Christodoulopoulos G, Dovas CI, Perrea D, Athansiou LV, Konstantopoulos P, Maes D, Papatsiros VG. Investigation of Fas (APO-1)-Related Apoptosis in Piglets Intradermally or Intramuscularly Vaccinated with a Commercial PRRSV MLV. Viral Immunol 2022; 35:129-137. [PMID: 35196156 DOI: 10.1089/vim.2021.0104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) induces apoptosis through the activation of death receptors, including cell-surface Fas receptor. The aim of this study was to investigate the impact of intradermal (ID) and intramuscular (IM) vaccination with a commercial PRRSV-modified live vaccine in piglets on Fas-related apoptosis. The study included 104 suckling piglets from a commercial farrow-to-finish pig farm, suffering from positive unstable PRRSV status. Animals were assigned in four groups: group A-Porcilis PRRS ID-vaccinated pigs, group B-Porcilis PRRS IM-vaccinated pigs, group C-Diluvac ID adjuvant-administered pigs, and group D-Diluvac IM adjuvant-administered pigs. Vaccines were administered at 2 weeks of age. Blood samples were collected from the same pigs at 4, 7, and 10 weeks of age. Sera were examined by quantitative real-time reverse transcription-PCR (qRT-PCR) for PRRSV and by ELISA for soluble Fas (sFas). At 4 weeks of age, all groups were negative qRT-PCR for PRRSV; at 7 weeks only group A was negative; and at 10 weeks all groups were positive. sFas was significantly increased in groups C (4 vs. 7, 4 vs. 10, and 7 vs. 10 weeks) and D (7 vs. 10 weeks). Significant differences among groups were noticed only at 10 weeks (A vs. C, A vs. D, B vs. C, B vs. D). A significant positive and moderate correlation between PRRSV viral load and Fas level was observed. In unvaccinated piglets, increased serum sFas levels reveal apoptotic suppression compared with vaccinated piglets. In the latter, vaccine-derived antibodies limit the infection and may attribute to the reduced Fas expression, suggesting a weak induction of lymphocyte-mediated cytotoxicity.
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Affiliation(s)
- Georgios Maragkakis
- Clinic of Medicine, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, Greece
| | - Laskarina-Maria Korou
- Laboratory for Experimental Surgery and Surgical Research, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Serafeim C Chaintoutis
- Diagnostic Laboratory, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Chrysostomos I Dovas
- Diagnostic Laboratory, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Despina Perrea
- Laboratory for Experimental Surgery and Surgical Research, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Labrini V Athansiou
- Clinic of Medicine, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, Greece
| | - Panagiotis Konstantopoulos
- Laboratory for Experimental Surgery and Surgical Research, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Dominiek Maes
- Department of Obstetrics-Reproduction and Herd Health, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Vasileios G Papatsiros
- Clinic of Medicine, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, Greece
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Commercial PRRS Modified-Live Virus Vaccines. Vaccines (Basel) 2021; 9:vaccines9020185. [PMID: 33671826 PMCID: PMC7926738 DOI: 10.3390/vaccines9020185] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/17/2021] [Accepted: 02/19/2021] [Indexed: 12/16/2022] Open
Abstract
Porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) presents one of the challenging viral pathogens in the global pork industry. PRRS is characterized by two distinct clinical presentations; reproductive failure in breeding animals (gilts, sows, and boars), and respiratory disease in growing pigs. PRRSV is further divided into two species: PRRSV-1 (formerly known as the European genotype 1) and PRRSV-2 (formerly known as the North American genotype 2). A PRRSV-2 modified-live virus (MLV) vaccine was first introduced in North America in 1994, and, six years later, a PRRSV-1 MLV vaccine was also introduced in Europe. Since then, MLV vaccination is the principal strategy used to control PRRSV infection. Despite the fact that MLV vaccines have shown some efficacy, they were problematic as the efficacy of vaccine was often unpredictable and depended highly on the field virus. This paper focused on the efficacy of commercially available MLV vaccines at a global level based on respiratory disease in growing pigs, and maternal and paternal reproductive failure in breeding animals.
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Choi HY, Lee SH, Ahn SH, Choi JC, Jeong JY, Lee BJ, Kang YL, Hwang SS, Lee JK, Lee SW, Park SY, Song CS, Choi IS, Lee JB. A chimeric porcine reproductive and respiratory syndrome virus (PRRSV)-2 vaccine is safe under international guidelines and effective both in experimental and field conditions. Res Vet Sci 2021; 135:143-152. [PMID: 33517163 DOI: 10.1016/j.rvsc.2021.01.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 01/11/2021] [Accepted: 01/21/2021] [Indexed: 12/12/2022]
Abstract
Vaccination is currently the most effective strategy to control porcine reproductive and respiratory syndrome (PRRS). New-generation PRRS vaccines are required to be safe and broadly cross-protective. We have recently created the chimeric PRRS virus K418DM which proved to be a good vaccine candidate under field conditions. In the present study, we designed safety and efficacy tests under experimental and field conditions for further evaluation of K418DM1.1, a plaque-purified K418DM. In the homologous challenge study, K418DM1.1 induced high serum virus neutralization (SVN) antibody titers (i.e., 4.2 log2 ± 1.7) at 21 days post-challenge (dpc) and provided protection as demonstrated by the significantly lower levels of viremia at 3 and 7 dpc and significantly lower microscopic lung lesion scores compared to the unvaccinated group. K418DM1.1 was also protective in the heterologous challenge study, with vaccinated pigs showing significantly lower levels of viremia at 14 dpc compared to the unvaccinated pigs. A field study was performed to evaluate the efficacy of K418DM1.1 against heterologous exposure and vaccinated pigs presented significantly lower viremia than unvaccinated pigs. According to the safety test for the examination of virulence reversion, no infectivity was observed in tissue homogenate filtrate both in the vaccinated and comingled groups. Thus, the risk of virulence, as well as transmission, appeared negligible. These overall results indicate that K418DM1.1 is a good vaccine candidate based on its safety and protective efficacy.
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Affiliation(s)
- Hwi-Yeon Choi
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - So-Hyun Lee
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - So-Hyeun Ahn
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Jong-Chul Choi
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Ji-Yun Jeong
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Beom-Joo Lee
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Yeong-Lim Kang
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Seong-Soo Hwang
- Samhwa Breedings Agri. Inc., 435, Sinjin-ri, Gwangcheon-eup, Hongseong-gun, Chungcheongnam-Do 350-900, Republic of Korea
| | - Jung-Keun Lee
- Department of Pathology and Population Medicine, College of Veterinary Medicine, Midwestern University, 19555, North 59th Avenue, Glendale, AZ 85308, USA
| | - Sang-Won Lee
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Seung-Yong Park
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Chang-Seon Song
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - In-Soo Choi
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Joong-Bok Lee
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
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Wei C, Dai A, Fan J, Li Y, Chen A, Zhou X, Luo M, Yang X, Liu J. Efficacy of Type 2 PRRSV vaccine against challenge with the Chinese lineage 1 (NADC30-like) PRRSVs in pigs. Sci Rep 2019; 9:10781. [PMID: 31346199 PMCID: PMC6658503 DOI: 10.1038/s41598-019-47239-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 07/03/2019] [Indexed: 11/09/2022] Open
Abstract
The objective of the present study was to determine the cross-protection of Ingelvac PRRS MLV against challenge with the new lineage 1 PRRSV emerged in China in pigs. Two lineage 1 PRRSV strains (FJZ03 and FJWQ16 originated from recombination event between NADC30 and JXA1-like strain). We found that pigs vaccinated with the vaccine were protected against challenge with the FJZ03 as shown by fewer days of clinical fever, reduced lung pathology scores, lower PRRS virus load in the blood and developed broadly neutralizing antibodies with high titers to FJZ03. In contrast, vaccine provided limited protection against challenge with FJWQ16 with higher fever, lower antibody titers, lower neutralizing antibodies and higher viral loads in blood. These results demonstrate PRRSV-MLV provides incomplete protection against new lineage 1 PRRSVs.
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Affiliation(s)
- Chunhua Wei
- College of Life Sciences of Longyan University, Longyan, 364012, Fujian, China.,Fujian Provincial Key Laboratory for the Prevention and Control of Animal Infectious Diseases and Biotechnology, Longyan University, Longyan, 364012, Fujian, China
| | - Ailing Dai
- College of Life Sciences of Longyan University, Longyan, 364012, Fujian, China.,Fujian Provincial Key Laboratory for the Prevention and Control of Animal Infectious Diseases and Biotechnology, Longyan University, Longyan, 364012, Fujian, China
| | - Jialin Fan
- College of Life Sciences of Longyan University, Longyan, 364012, Fujian, China.,Fujian Provincial Key Laboratory for the Prevention and Control of Animal Infectious Diseases and Biotechnology, Longyan University, Longyan, 364012, Fujian, China
| | - Yan Li
- College of Life Sciences of Longyan University, Longyan, 364012, Fujian, China.,Fujian Provincial Key Laboratory for the Prevention and Control of Animal Infectious Diseases and Biotechnology, Longyan University, Longyan, 364012, Fujian, China
| | - Anni Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, Guangdong, China
| | - Xia Zhou
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, Guangdong, China
| | - Manlin Luo
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, Guangdong, China
| | - Xiaoyan Yang
- College of Life Sciences of Longyan University, Longyan, 364012, Fujian, China.,Fujian Provincial Key Laboratory for the Prevention and Control of Animal Infectious Diseases and Biotechnology, Longyan University, Longyan, 364012, Fujian, China
| | - Jiankui Liu
- College of Life Sciences of Longyan University, Longyan, 364012, Fujian, China. .,Fujian Provincial Key Laboratory for the Prevention and Control of Animal Infectious Diseases and Biotechnology, Longyan University, Longyan, 364012, Fujian, China. .,College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, Guangdong, China.
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Jeong J, Kim S, Park C, Park KH, Kang I, Park SJ, Chae C. Commercial porcine reproductive and respiratory syndrome virus (PRRSV)-2 modified live virus vaccine against heterologous single and dual Korean PRRSV-1 and PRRSV-2 challenge. Vet Rec 2018; 182:485. [DOI: 10.1136/vr.104397] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 11/07/2017] [Accepted: 01/28/2018] [Indexed: 01/24/2023]
Affiliation(s)
- Jiwoon Jeong
- Department of Veterinary Pathology; Seoul National University, College of Veterinary Medicine; Seoul Republic of Korea
| | - Seeun Kim
- Department of Veterinary Pathology; Seoul National University, College of Veterinary Medicine; Seoul Republic of Korea
| | - Changhoon Park
- Department of Veterinary Pathology; Seoul National University, College of Veterinary Medicine; Seoul Republic of Korea
| | - Kee Hwan Park
- Department of Veterinary Pathology; Seoul National University, College of Veterinary Medicine; Seoul Republic of Korea
| | - Ikjae Kang
- Department of Veterinary Pathology; Seoul National University, College of Veterinary Medicine; Seoul Republic of Korea
| | - Su-Jin Park
- Department of Veterinary Pathology; Seoul National University, College of Veterinary Medicine; Seoul Republic of Korea
| | - Chanhee Chae
- Department of Veterinary Pathology; Seoul National University, College of Veterinary Medicine; Seoul Republic of Korea
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Park C, Choi K, Jeong J, Kang I, Park SJ, Chae C. Concurrent vaccination of pigs with type 1 and type 2 porcine reproductive and respiratory syndrome virus (PRRSV) protects against type 1 PRRSV but not against type 2 PRRSV on dually challenged pigs. Res Vet Sci 2015; 103:193-200. [DOI: 10.1016/j.rvsc.2015.10.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 10/19/2015] [Accepted: 10/25/2015] [Indexed: 11/30/2022]
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8
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Li Z, Wang G, Wang Y, Zhang C, Wang X, Huang B, Li Q, Li L, Xue B, Ding P, Syed SF, Wang C, Cai X, Zhou EM. Rescue and evaluation of a recombinant PRRSV expressing porcine Interleukin-4. Virol J 2015; 12:185. [PMID: 26573719 PMCID: PMC4647277 DOI: 10.1186/s12985-015-0380-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 09/09/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The current vaccines for porcine reproductive and respiratory syndrome virus (PRRSV) have failed to provide broad protection against infection by various strains of PRRSV. Porcine Interleukin-4 (pIL-4) plays an important role in the regulation of the immune response and has been used previously as an immunological adjuvant. The objective of this study was to construct a recombinant PRRSV expressing pIL-4 and to evaluate the immune response of the recombinant virus in piglets. METHODS The pIL-4 gene was inserted in the PRRSV (CH-1R strain) infectious clone by overlap PCR. Indirect immunofluorescence assay (IFA) and Western blotting were used to confirm the recombinant virus. The stability of the recombinant virus was assessed by DNA sequencing and IFA after 15 passages in vitro. Recombinant virus was injected into pigs and efficacy of immune protection was evaluated in comparison with the parental virus. RESULTS The recombinant virus (CH-1R/pIL-4) was successfully rescued and shown to have similar growth kinetics as the parental virus. The recombinant virus was stable for 15 passages in cell culture. Pigs vaccinated with CH-1R/pIL-4 produced a similar humoral response to the response elicited by parental virus, but IL-4 level in the supernatant of PBMCs from pigs vaccinated with CH-1R/pIL-4 was significantly higher than the parent virus at 28 days post-immunization (DPI). Flow cytometric (FCM) analysis showed that the percentage of CD4(+)CD8(+) double positive T (DPT) cells in the CH-1R/pIL-4 vaccinated group was significantly higher than the parental virus at 3 and 7 Days Post-Challenge (DPC), and the IL-4 level in the blood significantly increased at 7 DPC. However, the viral load and histopathology did not show significant difference between the two groups. CONCLUSIONS A recombinant PRRSV expressing porcine IL-4 was rescued and it remained genetically stable in vitro. The recombinant virus induced higher DPT ratios and IL-4 levels in the blood after HP-PRRSV challenge compared to the parental virus in piglets. However, it did not significantly improve protection efficacy of PRRSV vaccine.
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Affiliation(s)
- Zhijun Li
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
| | - Gang Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agriculture Science, Harbin, 150001, China.
| | - Yan Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
| | - Chong Zhang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agriculture Science, Harbin, 150001, China.
| | - Xinglong Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
| | - Baicheng Huang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
| | - Qiongyi Li
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
| | - Liangliang Li
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
| | - Biyun Xue
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
| | - Peiyang Ding
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
| | - Shahid Faraz Syed
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
| | - Chengbao Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
| | - Xuehui Cai
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agriculture Science, Harbin, 150001, China.
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
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Comparison of Two Commercial Type 1 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Modified Live Vaccines against Heterologous Type 1 and Type 2 PRRSV Challenge in Growing Pigs. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:631-40. [PMID: 25855554 DOI: 10.1128/cvi.00001-15] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 03/28/2015] [Indexed: 11/20/2022]
Abstract
The objective of the present study was to compare the efficacy of two commercial type 1 porcine reproductive and respiratory syndrome virus (PRRSV) modified live vaccines against heterologous type 1 and type 2 PRRSV challenge in growing pigs. Vaccination with a type 1 PRRSV vaccine reduced the level of viremia after type 1 PRRSV challenge but did not reduce the level of viremia after the type 2 PRRSV challenge in pigs. Increased levels of interleukin-10 (IL-10) stimulated by type 2 PRRSV coincided with the low numbers of type 2 PRRSV-specific interferon gamma-secreting cells (IFN-γ-SC) in vaccinated pigs after type 2 PRRSV challenge, whereas low levels of IL-10 stimulated by type 1 PRRSV coincided with high numbers of type 1 PRRSV-specific IFN-γ-SC in vaccinated pigs after type 1 PRRSV challenge. Additionally, vaccination with the type 1 PRRSV vaccine effectively reduced the lung lesions and type 1 PRRSV nucleic acids in type 1 PRRSV-challenged pigs but did not reduce lung lesions and type 2 PRRSV nucleic acids in type 2 PRRSV-challenged pigs. There were no significant differences between two commercial type 1 PRRSV vaccines against type 1 and type 2 PRRSV challenge based on virological results, immunological responses, and pathological outcomes. This study demonstrates that vaccinating pigs with the type 1 PRRSV vaccine provides partial protection against respiratory disease with heterologous type 1 PRRSV challenge but no protection with heterologous type 2 PRRSV challenge.
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Cross-protection of a new type 2 porcine reproductive and respiratory syndrome virus (PRRSV) modified live vaccine (Fostera PRRS) against heterologous type 1 PRRSV challenge in growing pigs. Vet Microbiol 2015; 177:87-94. [PMID: 25769646 DOI: 10.1016/j.vetmic.2015.02.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 02/15/2015] [Accepted: 02/17/2015] [Indexed: 11/22/2022]
Abstract
The objective of the present study was to determine the cross-protection of a new type 2 porcine reproductive and respiratory syndrome virus (PRRSV) modified live vaccine against heterologous type 1 PRRSV challenge in growing pigs. The mean rectal temperature and respiratory score was significantly (P<0.05) lower in vaccinated challenged pigs than in unvaccinated challenged pigs. Vaccination of pigs with type 2 PRRSV reduced the levels of type 1 PRRSV viremia after challenge with type 1 PRRSV. Vaccinated challenged pigs had significantly (P<0.05) higher frequency of interferon-γ secreting cells and lower levels of interleukin-10 compared to unvaccinated challenged pigs. Vaccination of pigs with the type 2 PRRSV effectively reduced the macroscopic and microscopic lung lesion and the type 1 PRRSV antigens within lung lesions in vaccinated challenged pigs. This study demonstrates partial cross-protection of a new type 2 PRRSV modified live vaccine against heterologous type 1 PRRSV challenge in growing pigs.
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11
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Park C, Seo HW, Han K, Kang I, Chae C. Evaluation of the efficacy of a new modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine (Fostera PRRS) against heterologous PRRSV challenge. Vet Microbiol 2014; 172:432-42. [PMID: 24970363 DOI: 10.1016/j.vetmic.2014.05.030] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Revised: 05/20/2014] [Accepted: 05/28/2014] [Indexed: 10/25/2022]
Abstract
The objective of this study was to evaluate a new modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine (Fostera PRRS, Zoetis, Florham, NJ, USA) that was based on a virulent US PRRSV isolate (P129) attenuated using CD163-expressing cell lines. Sixty-four PRRSV-seronegative 3-week-old pigs were randomly divided into the following four groups: vaccinated challenged (group 1), vaccinated unchallenged (group 2), unvaccinated challenged (group 3), and unvaccinated unchallenged (group 4). The pigs in groups 1 and 2 were immunized with a 2.0 mL dose of modified live PRRSV vaccine at 21 days of age, according to the manufacturer's recommendations. At 56 days of age (0 days post-challenge), the pigs in groups 1 and 3 were inoculated intranasally with 3 mL of tissue culture fluid containing 10(5) 50% tissue culture infective dose (TCID50)/mL of PRRSV (SNUVR090851 strain, fourth passage in MARC-145 cells). Vaccinated challenged pigs exhibited significantly lower (P<0.05) respiratory scores, viremia, macroscopic and microscopic lung lesion scores, and PRRSV-antigen with interstitial pneumonia than unvaccinated challenged pigs. The induction of PRRSV-specific IFN-γ-SCs by the new modified live PRRSV vaccine produced a protective immune response, leading to the reduction of PRRSV viremia. Although the new modified live PRRSV vaccine is not effective against heterologous PRRSV challenge, the new modified live PRRSV vaccine was able to reduce the levels of viremia and nasal shedding, and severity of PRRSV-induced lesions after challenging virus under experimental conditions.
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Affiliation(s)
- Changhoon Park
- Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
| | - Hwi Won Seo
- Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
| | - Kiwon Han
- Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
| | - Ikjae Kang
- Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
| | - Chanhee Chae
- Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
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Han K, Seo HW, Park C, Chae C. Vaccination of sows against type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) before artificial insemination protects against type 2 PRRSV challenge but does not protect against type 1 PRRSV challenge in late gestation. Vet Res 2014; 45:12. [PMID: 24484238 PMCID: PMC3923437 DOI: 10.1186/1297-9716-45-12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 01/22/2014] [Indexed: 02/03/2023] Open
Abstract
The objective of the present study was to determine the effects of the commercially available type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)-based modified live vaccine against type 1 and type 2 PRRSV challenge in pregnant sows. Half of the sows in the study were vaccinated with a type 2 PRRSV-based vaccine 4 weeks prior to artificial insemination while the other half remained non-vaccinated. Sows were then challenged intranasally with type 1 or type 2 PRRSV at 93 days of gestation. The sows which received the type 2 PRRSV-based vaccine followed by type 2 PRRSV challenge had significantly higher neutralizing antibody titers against type 2 PRRSV than they did against type 1 PRRSV. These same sows had higher frequencies of IFN-γ-secreting cells when stimulated with type 2 PRRSV compared to those stimulated with type 1 PRRSV. Subsequent virological evaluation demonstrated that the type 2 PRRSV-based vaccine reduced the type 2 PRRSV load but not the type 1 PRRSV load present in the blood of the sows. Additionally, vaccination of pregnant sows with the type 2 PRRSV-based vaccine effectively reduced the level of type 2 PRRSV nucleic acids observed in fetal tissues from type 2 PRRSV-challenged sows but did not reduce the level of type 1 PRRSV nucleic acid observed in fetal tissues from type 1 PRRSV-challenged sows. This study demonstrates that the vaccination of pregnant sows with the type 2 PRRSV-based vaccine protects against type 2 PRRSV challenge but does not protect against type 1 PRRSV challenge.
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Affiliation(s)
| | | | | | - Chanhee Chae
- Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
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Zhang HB, Wan XP, Bai GM, Gao LF, Chen C, Zhang H, Lv XB, Wang ZZ, Li JL, Gao R. Improvement Of The Immunity Of Piglets To PRRS Vaccine By A Porcine IL-4 And IL-6 Fusion Gene Encapsulated In Chitosan Nanoparticles. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.provac.2012.04.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Martelli P, Gozio S, Ferrari L, Rosina S, De Angelis E, Quintavalla C, Bottarelli E, Borghetti P. Efficacy of a modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine in pigs naturally exposed to a heterologous European (Italian cluster) field strain: Clinical protection and cell-mediated immunity. Vaccine 2009; 27:3788-99. [PMID: 19442420 DOI: 10.1016/j.vaccine.2009.03.028] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 02/10/2009] [Accepted: 03/16/2009] [Indexed: 01/06/2023]
Abstract
The purpose of this study was to assess clinical protection in pigs vaccinated with a commercially available attenuated porcine reproductive and respiratory syndrome virus (PRRSV) vaccine (Porcilis) PRRS) and then naturally exposed under field conditions to a heterologous (Italian cluster) strain of virulent PRRSV. A total of 30, 4-week-old pigs seronegative for PRRSV were allocated to 1 of 3 groups (IM, ID, and C groups). At 5 weeks of age, pigs of groups IM (n=10 pigs) and ID (n=10 pigs) were vaccinated intramuscularly and intradermally, respectively, with modified live PRRSV-1 vaccine (Porcilis) PRRS). Pigs of group C (n=10 pigs) were kept as non-vaccinated controls. At post-vaccination (PV) days 0, 7, 14, 28, and 45, blood samples were collected for detection of vaccine virus (PCR) and antibody response (ELISA), identification of changes in lymphocyte subpopulations by cytometry, and IFN-gamma PRRSV-specific secreting cells (SC) by ELISpot. At PV day 45, pigs of A, B, and C groups were moved to a site 3 conventional finishing herd with a history of respiratory disease caused by PRRSV and the most common bacteria to be exposed to a natural challenge. The PRRSV field strain, belonging to the Italian cluster of the PRRSV-1, demonstrated a 84% identity with the vaccine virus (DV strain) at ORF5 sequencing. At 0 (exposure day=45 days PV), 4, 7, 11, 14, 19, 21, 28, and 34 days post-exposure (PE) blood samples were collected for detection and titration of PRRSV and antibody, as well as for lymphocyte and IFN-gamma measurement as described above. Throughout the post-exposure period, all pigs were observed daily for clinical signs. The overall clinical signs were reduced by 68 and 72%, respectively in the intramuscularly and intradermally vaccinated pigs compared to controls. Respiratory signs were reduced by 72 and 80%, respectively in the IM and ID groups. Clinical protection was associated with marked activation of cell-mediated immune response. The highest levels of specific IFN-gamma production at 21-34 days PE were concomitant and associated to changes in natural killer (NK) cells, gamma/delta T, and cytotoxic T lymphocytes in the blood. In our field study, evidences of EU attenuated vaccine-induced clinical protection against natural exposure to a genetically diverse (84% homology) PRRSV-1 isolate (Italian cluster) was demonstrated by the statistically significant reduction in clinical signs in terms of incidence, duration and severity and by a more efficient cell-mediated immune response in the vaccinated pigs as compared to the unvaccinated controls.
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Affiliation(s)
- Paolo Martelli
- Department of Animal Health, University of Parma, Via del Taglio, 10, 43126 Parma, Italy.
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Prieto C, Alvarez E, Martínez-Lobo FJ, Simarro I, Castro JM. Similarity of European porcine reproductive and respiratory syndrome virus strains to vaccine strain is not necessarily predictive of the degree of protective immunity conferred. Vet J 2007; 175:356-63. [PMID: 17560818 DOI: 10.1016/j.tvjl.2007.01.021] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Revised: 12/28/2006] [Accepted: 01/26/2007] [Indexed: 11/29/2022]
Abstract
The objective of this study was to determine the degree of protection conferred by a Lelystad-like modified live virus (MLV) vaccine against a heterologous wild-type porcine reproductive and respiratory syndrome virus (PRRSV) isolate of the same cluster. For this purpose, fourteen 3-week-old piglets were divided into three groups: Group A pigs were vaccinated with a modified live virus vaccine, Group B pigs were used as positive controls, and Group C pigs as negative controls. Twenty-eight days after the last dose of vaccine, all pigs in Groups A and B were inoculated with the Spanish PRRSV strain 5710. To evaluate efficacy, clinical signs were recorded and the presence of challenge virus was determined by virus isolation in blood samples and nasal swabs collected at various time points post-challenge (p.c.) and in tissue samples collected at necropsy 24 days p.c. After challenge, moderate clinical signs were observed in pigs from Groups A and B. In addition, all vaccinated pigs were viremic at least once, although viremia tended to be more sporadic in this group than in Group B pigs. PRRSV was detected in at least one tissue sample from four out of five pigs from Group A and in all pigs from Group B. The results indicate that the protection conferred by the MLV vaccine used in this study against a closely related virulent strain was only partial. The findings suggest that the degree of genetic homology of ORF5 between MLV vaccine and challenge isolate is not a good predictor of vaccine efficacy.
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Affiliation(s)
- Cinta Prieto
- Dpto. de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
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Martelli P, Cordioli P, Alborali LG, Gozio S, De Angelis E, Ferrari L, Lombardi G, Borghetti P. Protection and immune response in pigs intradermally vaccinated against porcine reproductive and respiratory syndrome (PRRS) and subsequently exposed to a heterologous European (Italian cluster) field strain. Vaccine 2007; 25:3400-8. [PMID: 17276558 DOI: 10.1016/j.vaccine.2006.12.050] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Revised: 12/14/2006] [Accepted: 12/21/2006] [Indexed: 02/07/2023]
Abstract
The purpose of this study was to assess the immune response in pigs intradermally vaccinated with a commercially available attenuated porcine reproductive and respiratory virus (PRRSV) vaccine (Porcilis PRRS) and subsequently exposed to a heterologous (Italian cluster) field strain of virulent PRRSV. A total of 18, 4-week-old pigs seronegative for PRRSV were allocated to 1 of 3 groups (groups A, B, and C). At 5 weeks of age, pigs of groups A (n=6 pigs) and B (n=6 pigs) were vaccinated intramuscularly and intradermally, respectively, with Porcilis PRRS. The more conventional intramuscular route of vaccination was included for comparative purposes with the intradermal route of vaccination (performed with the I.D.A.L. vaccinator). Pigs of group C (n=6 pigs) were kept as nonvaccinated controls. At post-vaccination (PV) days 7, 14, 21, 28, and 35, blood samples were collected for detection of vaccine virus (PCR) and antibodies (ELISA), and for changes in PBMC (flow cytometry). At PV day 35, pigs of all groups were each exposed (challenged) intranasally to a heterologous field strain (78% ORF5 sequence homology between vaccine and field virus) belonging to the Italian cluster of the European genotype of PRRSV. At post-challenge (PC) days 0, 3, 7, 10, 13, and 17, blood samples were collected for detection and quantitation of virus and antibodies, and for changes in PBMC as described above for blood samples collected PV. Throughout the experiment all pigs were observed daily for clinical signs. At PC days 7 and 17, two pigs and four pigs, respectively, of each group were euthanized and examined for macroscopic lesions. Following vaccination some pigs of groups A and B had a detectable viremia that in two pigs (one pig of group A and one pig of group B) lasted until PV day 28. However, all pigs (groups A, B, and C) remained clinically normal. All vaccinated pigs developed a serological response (ELISA) to PRRSV. Presumptive evidence for vaccine-induced protective immunity against the heterologous challenge strain was provided by finding that viremia following challenge was generally less (incidence) and significantly less (titers) in vaccinated pigs than in nonvaccinated pigs. No differences were apparent between pigs vaccinated intramuscularly and those vaccinated intradermally. The absence of virulent-virus-induced clinical signs and macroscopic lesions in nonvaccinated as well as in vaccinated pigs precluded a more definitive evaluation of the magnitude of protective immunity provided by vaccination or by the route of vaccination. Some likely treatment-associated changes in lymphocyte subpopulations were observed among the three treatment groups. These changes and their potential relationship to protective immunity are discussed.
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Affiliation(s)
- Paolo Martelli
- Department of Animal Health, University of Parma, Via del Taglio, 8, 43100 Parma, Italy.
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Labarque G, Reeth KV, Nauwynck H, Drexler C, Van Gucht S, Pensaert M. Impact of genetic diversity of European-type porcine reproductive and respiratory syndrome virus strains on vaccine efficacy. Vaccine 2004; 22:4183-90. [PMID: 15474708 DOI: 10.1016/j.vaccine.2004.05.008] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2004] [Revised: 05/04/2004] [Accepted: 05/12/2004] [Indexed: 11/21/2022]
Abstract
The aim of this study was to find out how efficiently pigs that are vaccinated with an attenuated porcine reproductive and respiratory syndrome virus (PRRSV) vaccine based on a virus from the Lelystad cluster are protected against a European wild-type strain from the same or another genetic cluster. Two experiments were performed. In each experiment, 5-week-old PRRSV-seronegative pigs were vaccinated intramuscularly with 10(4.5) TCID50 of a commercial vaccine based on a European virus strain from the Lelystad cluster. Non-vaccinated pigs were included as controls. At 5, 9, 15, 20, 28, 35 and 42 days post vaccination (PV), broncho-alveolar lavage (BAL) fluids and blood were collected to determine vaccine virus quantities. Forty-nine days PV, pigs were challenged intranasally with 10(6.0) TCID50 of a European wild-type strain, belonging either to the Lelystad cluster (98% nucleotide identity in ORF5 with vaccine strain) (experiment A) or to an Italian cluster (84% nucleotide identity in ORF5 with vaccine strain) (experiment B). At 5, 9, 15, 20 and 27 days post challenge (PC), BAL fluids and blood were collected to determine virus quantities. Vaccine virus was first detected in BAL fluids and blood at 5 days PV and reached highest quantities between 9 and 15 days PV. One pig was positive in its BAL fluid until 42 days PV. After challenge, virus was isolated from BAL fluids and blood of all non-vaccinated control pigs. All vaccinated pigs challenged with the Lelystad strain remained negative for virus, while virus was present in BAL fluids and blood of all vaccinated pigs after challenge with the Italian strain. Mean virus titres of the vaccinated pigs challenged with the Italian strain were significantly lower than those of the non-vaccinated control pigs (P <0.05) at 9, 15 and 20 days PC. Thus, the genetic diversity within European-type PRRSV may affect the efficacy of the current European-type vaccines.
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Affiliation(s)
- G Labarque
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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Verheije MH, Kroese MV, van der Linden IFA, de Boer-Luijtze EA, van Rijn PA, Pol JMA, Meulenberg JJM, Steverink PJGM. Safety and protective efficacy of porcine reproductive and respiratory syndrome recombinant virus vaccines in young pigs. Vaccine 2003; 21:2556-63. [PMID: 12744891 DOI: 10.1016/s0264-410x(03)00047-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Three porcine reproductive and respiratory syndrome virus (PRRSV) recombinants, generated by mutagenesis of an infectious cDNA clone of the Lelystad virus (LV) isolate, were tested for their safety and protective efficacy as potential PRRSV vaccines in pigs. Recombinant vABV688 contains two amino acid substitutions in the minor structural protein GP(2) resulting in improved growth on cell line CL2621; in recombinant vABV707 the region encoding the ectodomain of the major unglycosylated membrane protein M has been replaced by that of the murine lactate dehydrogenase-elevating arterivirus; recombinant vABV746 lacks the six C-terminal amino acids of the nucleocapsid protein N. First, we determined the safety of these recombinant viruses by monitoring the stability of the introduced mutations in 8-week-old pigs. We showed that the introduced genomic mutations were maintained throughout the viraemic period. Second, the protective efficacy of immunization with the recombinant viruses against challenge with a homologous and a heterologous PRRSV strain was determined in two pigs and compared with the efficacy of vABV437, a virus derived from the parental LV cDNA. The viraemia in pigs immunized with the recombinant viruses was reduced compared to pigs immunized with vABV437. In addition, the length of viraemia was reduced in the sentinel pigs that were introduced into the groups immunized with vABV746, vABV688, and vABV707, however, all of the sentinel pigs became infected. Pigs immunized with vABV707 and vABV437 were protected against challenge with homologous virus LV-Ter Huurne and transmission of the latter virus. None of the immunized pigs were protected against heterologous challenge with the virulent US isolate SDSU#73, but the vABV707- and vABV746-immunized pigs were protected against transmission of this virus from challenged pigs. In conclusion, the obtained viral recombinants are interesting candidates to be further explored for their use as vaccines against PRRSV.
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Affiliation(s)
- M H Verheije
- Department of Infectious Diseases and Food Chain Quality, Institute for Animal Science and Health, Lelystad, The Netherlands.
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Delputte PL, Vanderheijden N, Nauwynck HJ, Pensaert MB. Involvement of the matrix protein in attachment of porcine reproductive and respiratory syndrome virus to a heparinlike receptor on porcine alveolar macrophages. J Virol 2002; 76:4312-20. [PMID: 11932397 PMCID: PMC155060 DOI: 10.1128/jvi.76.9.4312-4320.2002] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2001] [Accepted: 01/25/2002] [Indexed: 12/30/2022] Open
Abstract
The porcine reproductive and respiratory syndrome virus (PRRSV) has a very restricted tropism for well-differentiated cells of the monocyte-macrophage lineage, which is probably determined by specific receptors on these cells. In this study, the importance of heparinlike molecules on porcine alveolar macrophages (PAM) for PRRSV infection was determined. Heparin interacted with the virus and reduced infection of PAM up to 92 or 88% for the American and European types of PRRSV, respectively. Other glycosaminoglycans, similar to heparin, had no significant effect on infection while heparinase treatment of PAM resulted in a significant reduction of the infection. Analysis of infection kinetics showed that PRRSV attachment to heparan sulfate occurs early in infection. A heparin-sensitive binding step was observed which converted completely into a heparin-resistant binding after 120 min at 4 degrees C. Using heparin-affinity chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), it was observed that the structural matrix (M) and nucleocapsid (N) proteins attached to heparin. Nonreducing SDS-PAGE revealed that M bound to heparin mainly as a complex with glycoprotein GP(5) and that the N protein bound to heparin as a homodimer. GP(3), which was identified as a minor structural protein of European types of PRRSV, did not bind to heparin. Since the N protein is not exposed on the virion surface, it was concluded that the structural M protein and the M-GP(5) complex contribute to PRRSV attachment on a heparinlike receptor on PAM. This is the first report that identifies a PRRSV ligand for a cell surface heparinlike receptor on PAM.
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Affiliation(s)
- P L Delputte
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
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