Pathogenic characteristics of three genotype II porcine reproductive and respiratory syndrome viruses isolated from China

BACKGROUND: We examined differences in pathogenicity in pigs from China that had been experimentally infected with porcine reproductive and respiratory syndrome virus (PRRSV). METHODS: We compared pathogenic characteristics of a field isolate (GX-1/2008F), two PRRSV isolates (HN-1/2008, YN-1/2008) p...

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Autores principales: Shang, Youjun, Wang, Guangxiang, Yin, Shuanghui, Tian, Hong, Du, Ping, Wu, Jinyan, Chen, Yan, Yang, Shunli, Jin, Ye, Zhang, Keshan, Lu, Zengjun, Liu, Xiangtao
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3616938/
https://www.ncbi.nlm.nih.gov/pubmed/23282224
http://dx.doi.org/10.1186/1743-422X-10-7
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author Shang, Youjun
Wang, Guangxiang
Yin, Shuanghui
Tian, Hong
Du, Ping
Wu, Jinyan
Chen, Yan
Yang, Shunli
Jin, Ye
Zhang, Keshan
Lu, Zengjun
Liu, Xiangtao
author_facet Shang, Youjun
Wang, Guangxiang
Yin, Shuanghui
Tian, Hong
Du, Ping
Wu, Jinyan
Chen, Yan
Yang, Shunli
Jin, Ye
Zhang, Keshan
Lu, Zengjun
Liu, Xiangtao
author_sort Shang, Youjun
collection PubMed
description BACKGROUND: We examined differences in pathogenicity in pigs from China that had been experimentally infected with porcine reproductive and respiratory syndrome virus (PRRSV). METHODS: We compared pathogenic characteristics of a field isolate (GX-1/2008F), two PRRSV isolates (HN-1/2008, YN-1/2008) propagated in cells, and GX-1/2008F that had been propagated in cells (GX-1/2008). The clinical courses, along with humoral and cell-mediated responses, were monitored for 21 days post-infection (DPI). Animals were sacrificed and tissue samples used for gross pathological, histopathological and ultrastructure examination. RESULTS: At 2–3 DPI, animals infected with cell-propagated viruses exhibited signs of coughing, anorexia and fever. However their rectal temperature did not exceed 40.5°C. Viremia was detectable as early as 3 DPI in animals infected with HN-1/2008 and YN-1/2008. Animals inoculated with GX-1/2008F displayed clinical signs at 6 DPI; the rectal temperature of two animals in this group exceeded 41.0°C, with viremia first detected at 7 DPI. Seroconversion for all challenged pigs, except those infected with GX-1/2008, was seen as early as 7 DPI. All of these pigs had fully seroconverted by 11 DPI. All animals challenged with GX-1/2008 remained seronegative until the end of the experiment. Innate immunity was inhibited, with levels of IFN-α and IL-1 not significantly different between control and infected animals. The cytokines IFN-γ and IL-6 transiently increased during acute infection. All virus strains caused gross lesions including multifocal interstitial pneumonia and hyperplasia of lymph nodes. Inflammation of the stomach and small intestine was also observed. Lesions in the group infected with GX-1/2008F were more serious than in other groups. Transmission electron microscopy revealed that alveolar macrophages, plasmacytes and lymphocytes had fractured cytomembranes, and hepatocytes had disrupted organelles and swollen mitochondria. CONCLUSIONS: The pathogenicity of the PRRSV field isolate became attenuated when propagated in MARC-145 cells. Tissue tropism of highly pathogenic strains prevailing in China was altered compared with classical PRRSV strains. The observed damage to immune cells and modulation of cytokine production could be mechanisms that PRRSV employs to evade host immune responses.
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spelling pubmed-36169382013-04-05 Pathogenic characteristics of three genotype II porcine reproductive and respiratory syndrome viruses isolated from China Shang, Youjun Wang, Guangxiang Yin, Shuanghui Tian, Hong Du, Ping Wu, Jinyan Chen, Yan Yang, Shunli Jin, Ye Zhang, Keshan Lu, Zengjun Liu, Xiangtao Virol J Research BACKGROUND: We examined differences in pathogenicity in pigs from China that had been experimentally infected with porcine reproductive and respiratory syndrome virus (PRRSV). METHODS: We compared pathogenic characteristics of a field isolate (GX-1/2008F), two PRRSV isolates (HN-1/2008, YN-1/2008) propagated in cells, and GX-1/2008F that had been propagated in cells (GX-1/2008). The clinical courses, along with humoral and cell-mediated responses, were monitored for 21 days post-infection (DPI). Animals were sacrificed and tissue samples used for gross pathological, histopathological and ultrastructure examination. RESULTS: At 2–3 DPI, animals infected with cell-propagated viruses exhibited signs of coughing, anorexia and fever. However their rectal temperature did not exceed 40.5°C. Viremia was detectable as early as 3 DPI in animals infected with HN-1/2008 and YN-1/2008. Animals inoculated with GX-1/2008F displayed clinical signs at 6 DPI; the rectal temperature of two animals in this group exceeded 41.0°C, with viremia first detected at 7 DPI. Seroconversion for all challenged pigs, except those infected with GX-1/2008, was seen as early as 7 DPI. All of these pigs had fully seroconverted by 11 DPI. All animals challenged with GX-1/2008 remained seronegative until the end of the experiment. Innate immunity was inhibited, with levels of IFN-α and IL-1 not significantly different between control and infected animals. The cytokines IFN-γ and IL-6 transiently increased during acute infection. All virus strains caused gross lesions including multifocal interstitial pneumonia and hyperplasia of lymph nodes. Inflammation of the stomach and small intestine was also observed. Lesions in the group infected with GX-1/2008F were more serious than in other groups. Transmission electron microscopy revealed that alveolar macrophages, plasmacytes and lymphocytes had fractured cytomembranes, and hepatocytes had disrupted organelles and swollen mitochondria. CONCLUSIONS: The pathogenicity of the PRRSV field isolate became attenuated when propagated in MARC-145 cells. Tissue tropism of highly pathogenic strains prevailing in China was altered compared with classical PRRSV strains. The observed damage to immune cells and modulation of cytokine production could be mechanisms that PRRSV employs to evade host immune responses. BioMed Central 2013-01-03 /pmc/articles/PMC3616938/ /pubmed/23282224 http://dx.doi.org/10.1186/1743-422X-10-7 Text en Copyright ©2013 Shang et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research
Shang, Youjun
Wang, Guangxiang
Yin, Shuanghui
Tian, Hong
Du, Ping
Wu, Jinyan
Chen, Yan
Yang, Shunli
Jin, Ye
Zhang, Keshan
Lu, Zengjun
Liu, Xiangtao
Pathogenic characteristics of three genotype II porcine reproductive and respiratory syndrome viruses isolated from China
title Pathogenic characteristics of three genotype II porcine reproductive and respiratory syndrome viruses isolated from China
title_full Pathogenic characteristics of three genotype II porcine reproductive and respiratory syndrome viruses isolated from China
title_fullStr Pathogenic characteristics of three genotype II porcine reproductive and respiratory syndrome viruses isolated from China
title_full_unstemmed Pathogenic characteristics of three genotype II porcine reproductive and respiratory syndrome viruses isolated from China
title_short Pathogenic characteristics of three genotype II porcine reproductive and respiratory syndrome viruses isolated from China
title_sort pathogenic characteristics of three genotype ii porcine reproductive and respiratory syndrome viruses isolated from china
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3616938/
https://www.ncbi.nlm.nih.gov/pubmed/23282224
http://dx.doi.org/10.1186/1743-422X-10-7
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