Effect of Recombinant Cyhv3IL-10 on Cell-Mediated Immuno-Cytokine Regulation in CyHV-3 Infection.

• Main Authors: Ting-Hsuan Hsu, 許庭瑄
• Other Authors: 陳媺玫
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/ek6x7u

碩士 === 國立臺灣大學 === 獸醫學研究所 === 106 === The cyprinid herpesvirus 3 (CyHV-3, KHV) is taxonomically grouped within the genus of cyprius, the family Alloherpesviridae and the order of herpesvirales. The genome size of CyHV-3 is 295 kb and mature viral particles are 167 to 200 nm in diameter and are surrounded by double strand DNA envelope. CyHV-3 is highly contagious and highly lethal to Cyprinus carpio (Cyprinus carpio), koi (Cyprinus carpio haematopterus) and the common carp hybrids that cause serious impact to aquaculture. CyHV-3, as the same as other herpesvirus, may cause inapparent infection which is associated with immune evasion. There are five proteins related to immune evasion discovery through genome analysis of CyHV-3 in 2007 by Aoki., et al. These proteins are G-protein coupled receptor (encoded by ORF16), TNFR homologues (encoded by ORF4 and ORF12), E3L like protein (encoded by ORF112) and an interleukine-10 (IL-10) homologue (encoded by ORF134). Furthermore, IL-10 is one of the most important anti-inflammatory cytokines with a key role in the termination of inflammation and restoration of homeostasis, suggesting that CyHV-3 IL-10 might have functions on host immunosuppression, resulting that virus can’t be completely removed by host. The important immunomodulatory functions that ensure viral persistence in the host, then became carriers, cause persistent infection. Persistent infection is a major risk for CyHV-3 prevention, thus causing the virus to spread quickly, resulting in a serious lethality. Therefore, this is mainly to study cyhv3IL-10 protein. In this study, cyhv3IL-10 recombinant protein (rvIL-10) is applied in the in vivo experiment to verify the function of rvIL-10 in koi inflammatory response and anti-viral pathways immune mechanism regulation. The in vitro study, IL-12 gene and IL-10 accessory gene socs-3 produced by macrophage are measured to evaluate the bioactivity of cyhv3IL-10 proteins. The results showed that after the administration of rvIL-10 protein, the death number of koi was less than the control group, and the virus replication is also limited. In addition, the regulations of cell-mediated immune response present a delayed phase. In conclusion, this study provided a new insight that rvIL-10 may have the potential to be used to reduce the symptoms produced after CyHV-3 infection. However, the mechanism of rvIL-10 regulations still needs further studies.