[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.