Abstract: LU Yuan *, LIAN Cui-hong. *Department of Dermatology, Nanshan Hospital Affiliated to Guangdong Medical College, Shenzhen 518052, China Corresponding author: LIAN Cui-hong, Email: cuihong_lian@yahoo.com.cn 【Abstract】 Objective To evaluate the immunogenicity of a recombinant adenovirus containing the porin IB （PIB） gene and Neisseria surface protein A （NspA） gene of N. gonorrhoeae in BALB/c mice. Methods A recombinant adenovirus containing the PIB gene and NspA gene of N. gonorrhoeae （pAdEasy-1-PN） was constructed in previous studies. Thirty BALB/c mice were randomly and equally divided into 5 groups: low-, medium- and high-dose experiment group intramuscularly immunized with 104, 106, and 108 50% tissue culture infective dose （TCID50） of the recombinant adenovirus pAdEasy-1-PN, respectively, pAdEasy-1 control group immunized with 106 TCID50 of pAdEasy-1, blank control group immunized with sodium chloride physiological solution. Immunization was carried out twice at a 4-week interval. Serum samples were collected at 0, 3 and 5 weeks after the first immunization, and spleens were removed at 5 weeks followed by the isolation of spleen lymphocytes. Enzyme linked immunosorbent assay （ELISA） was performed to determine the serum levels of PIB-specific and NspA-specific antibodies, methyl thiazolyl tetrazolium （MTT） assay to evaluate the proliferaton activity of spleen lymphocytes after stimulation by the recombinant PIB and NspA antigens. A slide agglutination test was used to estimate the anti-bacterial activity of murine serum. The complement-dependent bacteriolytic activity of murine serum was also evaluated. Statistical analysis was carried out by t test. Results Both humoral and cellular immune response specific to PIB and NspA were elicited by the recombinant adenovirus in mice. At 3 and 5 weeks after the immunization, significant differences were observed in the serum levels of PIB-specific （F = 285.72, 564.83, respectively, both P < 0.01） and NspA-specific （F = 521.57, 542.61, respectively, both P < 0.01） antibodies. Also, the proliferation index was statistically different among these groups in spleen lymphocytes stimulated with PIB and NspA （F = 171.61, 233.96, respectively, both P < 0.01）. The vaccination efficiency was positively correlated with the inoculation dose of recombinant pAdEasy-1-PN, and 108 TCID50 per dose proved to be the optimal dose for immunization. The sera from mice immunized with pAdEasy-1-PN could agglutinate N. gonorrhoeae and kill it in the presence of complement. Conclusions The recombinant adenovirus pAdEasy-1-PN containing PIB and NspA genes could induce specific humoral and cellular immune response in mice, and may be a potential vaccine against N. gonorrhoeae. 【Key words】 Neisseria gonorrhoeae; Adenoviridae; Vaccines, DNA