Expression and Evaluation of Feline Interferon against Feline Coronavirus Infection

• Main Authors: Chi-Chi Wen, 溫琦琦
• Other Authors: 闕玲玲
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/81509956586984269933

碩士 === 國立臺灣大學 === 獸醫學研究所 === 101 === Feline infectious peritonitis (FIP) is a fetal immune-mediated disease caused by feline coronavirus (FCoV). At present, effective vaccine and treatments are still unavailable for FIP. Interferons (IFNs) are cytokines produced by the host animals upon virus infection. With either immune-modulation or antiviral effect, some IFNs have been using routinely in the clinic of human medicine. There are three feline IFN (feIFN) i.e., feIFN-α, β, ω, that shown anti-FCoV activity in vitro. As the expression level of IFN-γ appeared to be markedly depressed in FIP-cats in comparison to clinically healthy feline coronavirus-infected cats. Higher IFN-γ production has been suggested to prevent the onset of FIP. Therefore, we attempted in this study to clone feIFN-γ gene from feline lymphocytes and to synthesis feIFN-ω gene. Using an E.coli expression system the recombinant feIFN-γ and feIFN-ω were evaluated in vitro for their possibility to be used in the future FIP therapy. The result showed that 1-1000 LRU/ml (Laboratory reference units/ml) IFN-γH can inhibit FCoV replication up to 28-40%, and that 0.8-105 LRU/ml IFN-ωH can inhibit FCoV replication up to 94.6-99.5%, both IFN-γH and IFN-ωH did not produce any cytotoxicity in high concentration 2000 LRU/ml and 106 LRU/ml respectively by using cell viability assay. For the immune modulatory effect, after treating monocytes and lymphocytes by IFN-γH, the expression of IL-12 and IFN-γ mRNA were both found increased. Taking these results together, the recombinant feIFN-γ and feIFN-ω could be the potential candidates for clinical FIP therapy.