Abstract: Objective To test the expression of recombinant plasmid pcDNA-L1 and evaluate its efficiency to induce specific humoral immune responses. Methods The local HPV16-L1 gene was generated by polymerase chain reaction, inserted into pGEM-T Easy cloning vector, and then subcloned into the eukaryotic expression vector pcDNA3.1（-）. The expression of recombinant plasmid pcDNA-L1，transferred in Cos-7 cells, was identified by immunofluorescence. The 6-week-old BALB/c mice were immunized via muscular 3 times with pcDNA-L1, thereafter the sera antibody of were measured by immunofluorescence and western-blot. Results With the immunofluorescence technique, L1 protein was found to express transiently in the transfected cells of the pcDNA-L1. Specific anti-HPV16-L1 antibodies could be detected by IFA at the end of 30,60 and 180 days after the first immunization, No specific antibodies could be detected in the control group of pcDNA3.1（-）. Conclusions The recombinant plasmid pcDNA-Ll DNA constructed by us could induce specific immuno-humoral response in mice.

Key words: Human papillomavirus type 16, L1 gene, Immuno-humoral, Mice.