Immunological Effects of Human Beta-defensin 2 Combined with HPV16 E7c Fragment in BALB/c Mice

Objective To explore the immunological effects of human beta-defensin 2 combined with human papillomavirus type 16 E7c and the cellular immune responses in BALB/c mice.Methods Thirty BALB/c mice were randomly divided into three groups,with 10 mice in each group.Mice in PBS group,pcDNA3.1(+)/E7c group and pEGFP-C1/HBD2-E7c group were primarily immunized into quadriceps muscle by intramuscular injection of PBS 100 μg,pcDNA3.1(+)/E7c plasmid 100 μg and pEGFP-C1/HBD2-E7c plasmid 100 μg,respectively.Booster immunization was performed two times 2 weeks after primary immunization.Mice were sacrificed by cervical dislocation at 7 days after the last immunization and spleens were weighed to calculate the spleen index.The number of spleen lymphocytes was measured,and number of subsets of CD4+ and CD8+ cells and CD4+/CD8+ ratio were determined by flow cytometry.Serum samples were collected by eyeball removal and E7-specific antibodies were measured by ELISA.Results Compared with PBS group,the spleen index and CD4+/CD8+ ratio significantly decreased but the proportion and number of CD4+ and CD8+ cells and serum levels of E7-specific antibodies obviously increased in both pEGFP-C1/HBD2-E7c group and pcDNA3.1(+)/E7c group(P0.05 or P0.01).Compared with pcDNA3.1(+)/E7c group,serum levels of E7-specific antibodies remarkably increased in pEGFP-C1/HBD2-E7c group(P0.05).Conclusion Human-beta defensin 2 can improve the immunogenicity of HPV16 E7c gene,enhance the levels of E7-specific antibodies and increase the number of CD4+ and CD8+ T lymphocytes.