日本脑炎病毒C蛋白对其复制子载体自主复制活性的影响

为了研制具有高效自主复制能力的日本脑炎病毒 (JEV) 复制子载体，验证其作为新型复制子疫苗载体的可能性。以保留全长核心蛋白C基因的JEV复制子载体pCTCJEV为基础，通过PCR的方法减短C蛋白的部分基因序列，分别保留C23和C68位氨基酸，以Lac Z基因作为报告基因，构建了C基因长短不同的JEV复制子载体pCMW-2M-1LACZ、pCMW-2M-3LACZ。将复制子载体转染表达JEV结构蛋白的细胞系CME-4，通过Lac Z的表达检测JEV复制子载体表达外源蛋白的能力，反映了JEV的系列复制子载体的自主复制能力。结果保留C基因全长，C68、C23的复制子载体表达外源蛋白的能力相当，以上结果说明仅仅保留C蛋白的69个核苷酸即可保留JEV复制子载体的自主复制能力，为进一步优化JEV复制子载体，将该载体开发研制成为高效表达外源蛋白的疫苗载体提供了依据。

Influence of Japanese enciphalitis virus capsid protein on the self-replicate ability of JEV replicon vectors

To optimize a self-replicate Japanese enciphalitis virus (JEV) replicon, and to make it as an efficient vector to express the heterologous protein, we constructed three JEV replicons by PCR-based shortening the length of capsid genes. The vectors remained full or part of C gene, based on the JEV replicon pCTCJEV. Lac Z was selected as the reporter gene to verify the self-replicate ability of these DNA-based replicons. While transfected into the cell lines CME-4, which continuously expressing the JEV structure proteins C-prM-E, the JEV replicons pCMW-2M-1LACZ, pCMW-2M-3LACZ, which remained the first 23aa and 68aa of C protein, can express the reporter protein as the same level as pCMW-2M-LACZ with the full-length C protein. These results illustrated that the JEV replicon vector with 69-nt of the C gene can retain the self-replicate ability, and provide valuable tools to construct a possible vector for a long-lasting JEV RNA virus expression system.