Involvement of the JNK-like protein of the Aedes albopictus mosquito cell line, C6/36, in phagocytosis, endocytosis and infection of West Nile virus
Involvement of the JNK-like protein of the Aedes albopictus mosquito cell line, C6/36, in phagocytosis, endocytosis and infection of West Nile virus
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DOI：
10.1046/j.1365-2583.2003.00435.x
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发表时间：
2003-10-01
影响因子：
2.6
通讯作者：
Takashima, I
中科院分区：
文献类型：
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作者：
Mizutani, T;Kobayashi, M;Takashima, I
我们最近从C6/36细胞系中克隆了c-Jun氨基末端激酶（JNK）序列，该细胞系来自白纹伊蚊。我们发现，SP 600125，JNK蛋白的抑制剂，抑制C6/36细胞的吞噬作用，这表明JNK样蛋白调节吞噬作用。在这里，我们表明，C6/36细胞组成性表达低水平的抗菌肽，天蚕素和防御素的mRNA编码，但这些mRNA的上调后，由脂多糖（LPS）的刺激。因此，C6/36细胞具有与哺乳动物巨噬细胞相似的性质。为了进一步表征C6/36细胞的功能特性，我们分析了JNK样蛋白在吞噬作用、内吞作用和病毒感染中的作用。C6/36细胞吞噬细菌和人工珠粒，并且这在LPS刺激后仅略微上调，表明新刺激的JNK样蛋白对于吞噬作用不是必需的。SP 600125抑制细胞内区室的酸化，包括参与内吞途径的那些。用SP 600125或巴弗洛霉素A1预处理C6/36细胞，而不是细胞松弛素D，抑制西尼罗河病毒（WNV）的进入，表明WNV主要通过内吞作用内化，JNK信号通路对内吞进入很重要。这些发现表明JNK样蛋白调节基本的生理功能，包括吞噬和内吞作用和感染西尼罗河病毒。
We recently cloned a c-Jun amino-terminal kinase (JNK) sequence from the C6/36 cell line, derived from the mosquito Aedes albopictus. We showed that SP600125, an inhibitor of JNK proteins, inhibits phagocytosis by C6/36 cells, suggesting that the JNK-like protein regulates phagocytosis. Here, we show that C6/36 cells constitutively express low levels of mRNA encoding the antibacterial peptides, cecropin and defensin, but that these mRNAs were up-regulated upon stimulation by lipopolysaccharide (LPS). Thus, the C6/36 cells have properties similar to those of mammalian macrophages. To characterize further the functional properties of C6/36 cells, we have assayed the role of the JNK-like protein in phagocytosis, endocytosis, and viral infection. C6/36 cells phagocytosed bacteria and artificial beads, and this was only slightly up-regulated following LPS stimulation, suggesting that newly stimulated JNK-like protein was not necessary for phagocytosis. SP600125 inhibited the acidification of intracellular compartments, including those involved in the endocytic pathway. Pretreatment of C6/36 cells with SP600125 or bafilomycin A1, but not cytochalasin D, inhibited the entry of West Nile virus (WNV), suggesting that WNV is internalized mainly by endocytosis, and that the JNK signalling pathway is important for endocytic entry. These findings indicate that the JNK-like protein regulates basic physiological functions, including phagocytosis and endocytosis and infection of WNV.