台灣豬隻的Toll-like receptor 4及9中膜外蛋白的分子特性分析

國內大多數豬場飼養密度過高以及擁擠，疾病常常侵襲豬隻，在革蘭氏陰性菌（Gram-negative bacteria）中，霍亂沙門氏桿菌（Salmonella choleraesuis）豬胸膜肺炎放線桿菌（Actinobacillus pleuropneumoniae）等，導致敗血症和肺炎等等嚴重的疾病。先天免疫系統是防禦和抵禦入侵微生物的第一線，Toll-like receptors （TLRs）是膜上接受器家族的一員，在辨識各式各樣病原體如細菌、真菌、病毒中扮演一個重要的角色.而其中TLR 4可以去辨認革蘭氏陰性菌（Gram-negative bacteria），而 TLR9則對細菌DNA未甲基化CpG motif有所感受性，TLR4 是啟動對蘭氏陰性細菌上脂多醣（Lipopolysaccharide）的先天反應是必須的訊傳的接受器而TLR 9則是對細菌的未甲基化 CpG 有高度的敏感度。另一方面豬產業面對獨特的一些相關病原，豬的TLR 4和9的基因型被預期在未來用來提高對傳染病的抵抗。我們首先從分子層面定出臺灣豬隻上TLR4 and 9 膜外蛋白特性及表現其蛋白，而研究發現胺基酸上321、343和535位置與外國的豬隻有所不同而另一方面TLR 9 基因有著高度保留性，在未來TLR4與9在不同豬隻病源中所扮演的角色是須要進一步研究的。

關鍵字

TLR9 ； TLR4

並列摘要

The domestic majority pig farms are raising density and over crowded. The pigs are often attacked by many pathogens. In the Gram-negative bacteria, Salmonella choleraesuis and Actinobacillus pleuropneumoniae, resulted in the septicaemia and pneumonia and so on serious diseases. The innate immune system was the first line of defense and against invading pathogenic microbes. Toll-like receptors （TLRs）are a family of membrane receptors which play a pivotal role in sensing a wide range of invading pathogens including bacteria, fungi and viruses. TLR4 can recognize the Gram-negative bacteria. The TLR9 confers responsiveness to bacterial DNA via species-specific CpG motif. TLR4 was essential for initiating the innate responses to lipopolysaccharide （LPS） by acting the specific signaling pathways. TLR9 have high sensitivity to bacterial DNA via species-specific CpG motif. As the pig industry faced a unique array of related pathogens, it was anticipated that the genotype of swine TLR4 and 9 are crucial important in future strategies aimed at improving genetic resistance to infectious diseases. In the beginning, we characterized the TLR4 and 9 ectodomain of Taiwan porcine in molecular level and express the TLR 4 protein. According to the results, we found the amino acid position of 321, 343 and 535 is different from foreign pigs. On the other hand, the gene of TLR9 is highly conserved. In the future, the role of TLR4 and 9 in different porcine pathogens are needed to be revealed.

並列關鍵字

TLR9 ； TLR4

參考文獻

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台灣豬隻的Toll-like receptor 4及9中膜外蛋白的分子特性分析

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