Cytokine profiles and virus loading in PCV2-induced granulomatous lesions
| Autor: | Chin-Hao Hu, 胡金灝 |
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| Rok vydání: | 2004 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 92 The main purpose of this study was to investigate the pathogenesis between PCV2 infection and PMWS lesions, namely histiocytosis or granulomatous lesions. Alveolar macrophages (AM) and peripheral blood monocytes (PBM) were obtained from 5 to 10-week-old healthy pigs free of PCV2 and PRRSV infection. The AM and PBM were inoculated with PCV2 and the viability, infectious rate, and morphological changes were observed and recorded. The supernatants were collected and the cytokine profiles were examined using commercial ELISA kits. Meanwhile, paraffin-embedded lymphoid tissues of field PMWS cases, which were negative in PCR results of pseudorabies virus, PRRS virus, and classic swine fever virus, were collected and graded for different stages of granulomatous lymphadenitis. Serial sections were made and detected later by in situ hybridization for the distribution of PCV2 viral nucleic acid. Immunohistochemical stainings for several granulomatous lesion-related cytokines, such as IL-1β, IL-8, IL-10, and IFN-γ, were performed. The results revealed that AM and PBM produced high levels of IL-1β and IL-8 in response to PCV2 infection, compared with non-infected cells. The significant effect of PCV2 infection on these cells started at 24 hours post infection.. In the 192 hours of incubation, the decrease in viability of PAM and PBM were also noted. The results of immunohistochemistry staining for cytokines revealed high expression of IFN-γ and IL-1β in the lymph nodes of PMWS pigs, compared with the control SPF pigs. The expression of IFN-γ was strong in the lymph nodes accompanied with lesions of histiocytosis. The expression of IL 1-β was strong in the lymph nodes accompanied with lesions of granulocytic infiltration. The distribution of PCV2 seemed to have no correlation with the distribution of cytokine signals. However, the viral loadings were strong in lymph nodes with histiocytosis lesions. The immnunohistochemistry staining result of IL-8 revealed minimal to negative pattern compared with the results of in vitro system, while IL-10 results were both negative in the in vitro system and IHC. In conclusion, PCV2 infection might enhance IFN-γproduction and thus trigger the granulomatous reactions. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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