[Influence of HBV gene immunization by introduction of nuclear localization signal into eukaryonized T7 expression...

To investigate the effects of nuclear localization signal on immune response induced by eukaryonized T7 expression system. Nuclear localization signal (NLS) coding sequence was introduced into eukaryonized T7 expression system containing HBV M protein coding gene. Naked gene immunization was performed. The results showed that the expression efficiency of T7 system which containing nuclear localization signal in vitro was lower than that without NLS. In vivo study found that HBV specific immune response induced by NLS lacking eukaryonized T7 system was significantly higher than that in eukaryonized T7 expression system containing NLS. HBV specific Th1 and Th2 type immune responses were also observed in the mice immunized with T7-HBsAg plasmid lacking NLS, indicating that the nuclear localization signal might not be essential in T7 expression system.