Objective:To observe whether the HPV16L1VLP Hela-cell binding-inhibition experiment can assess the immune-protective activities of HPV16L1 antibody in HPV16 prophylactic vaccine or other fields.Methods:C57BL/6 mice were divided into three groups,including pcDNAL1 plasmid,HPV16L1VLP protein,pcDNA3.1 plasmid.Each group of mice was immunized intramuscularly or subcutaneously with certain above antigens,accompanying three times and interval 3 weeks.After 14 days of 3 rd immunization,take blood to make serum for immunochemistry.Results:Hela cell neutralized by the serum IgG of experimental mice can be stained negatively,while the cells of control and non-inoculation groups can be stained positively (brown-yellow color).Conclusion:HPV16LIVLP Hela-cell binding-inhibition assay may be the better way to reflect the neutralizing-protective activities of HPV16L1 antibody in many fields including HPV16 prophylactic vaccine.

OBJECTIVETo investigate the specific cell-mediated immune efficacy of the an HPV16 prophylactic vaccine.

METHODSC57BL/6 mice were randomly divided into 3 groups: experimental group I (treated with pcDNA L1), control group II (treated with pcDNA3.1) and control group III (treated with PBS buffer). The mice were immunized three times during a three-week interval. Ten to fourteen days after the third inoculation, a footpad swelling test was used to detect delayed-type hypersensitivity (DTH) responses. Antigen-specific splenocyte proliferation assay and quantitation of IFN-gamma cells in splenocytes were performed by FACS assay.

RESULTSIn the experimental group, splenocytes actively proliferated after stimulation with HPV16 VLP, and had developed a markedly larger amount of CD8(+) IFN-gamma(+) cells, which is an index for special CTL. Also, the footpad was significantly thickened upon inoculation with HPV16 VLP.

CONCLUSIONNaked DNA vaccine of HPV16 L1 can induce specific cell-mediated immune responses in mice, which should be considered for evaluation of HPV16 DNA vaccine feasibility.

Animals ; Hypersensitivity, Delayed ; etiology ; Immunization ; Interferon-gamma ; biosynthesis ; Lymphocyte Activation ; Mice ; Mice, Inbred C57BL ; Papillomaviridae ; immunology ; Spleen ; cytology ; Vaccines, DNA ; immunology ; Viral Vaccines ; immunology

Objective It has been well accepted that human papillomavirus type 16 (HPV16) is associated with human cervical cancer and HPV16 L1 protein could induce both humoral and cellular immune responses. The objective of this study is to map epitopes on HPV16 L1 protein and to provide information to the design of HPV16 prophylactic peptide vaccine.Methods The epitopes on L1 protein were screened by polyclonal and 2 monoclonal antibodies (B8 and F4G3) against HPV16 L1 protein from a 6-mer phage display epitope library with the method of immuno-affinity screening (Bio-panning). After 3 rounds of Bio-panning, the positive phages were detected by L1 antibodies again with ELISA. The positive phages reacted strongly with L1 antibodies were then identified by DNA sequencing.Results Three mimotopes have been screened by polyclonal and two monoclonal antibodies. The mimotope (LSLFSC) which reacted with monoclonal antibody B8 showed 50% homology with the sequence 270～275a.a (DSLFFY) of prototype HPV16 L1. Another mimotope (LTSSYS) which reacted with polyclonal antibodies had 66% homology with the L1 sequence 516～521a.a (TTSSTS), also a mimotope (DRWDRF) was found to have the homologic RF with the known L1 sequense 441～446a.a. The mimotopes LSLFSC and DRWDRF were adjacent to the epitopes at 267～269a.a and 422～441a.a reported by other researchers previously.Conclusions Our results suggested that there might be a batch of epitopes on HPV16 L1 protein, and the predominant epitopes of HPV16 L1 protein were located in the above two domains. These results would be heplful for the design of HPV16 prophylactic peptide vaccines and HPV polyvalent vaccines.