HPV16 L1 gene was amplified from HPV16 positive vaginal secretion sample by PCR, and inserted into pTO-T7 to obtain the recombinant expression vector pTO-T7-HPV16-L1. Then, the pTO-T7-HPV16-L1 was transformed into E. coil strain ER2566 and the recombinant protein HPV16 L1 was expressed in soluble form. After purification by ammonium sulfate precipitation, ion-exchange chromatography, and hydrophobic interaction chromatography, the recombinant protein HPV16 L1 had a purity of more than 98%. By removing DTT, purified HPV16 L1 proteins self-assembled in vitro into VLPs with the diameter of 50 nm. The vaccination experiments on experimental animals showed the VLPs could elicit high titer of neutralizing antibodies against HPV 16. HPV16 VLPs with high immunogenicity and high purity can be produced easily and effectively from an E. coli expression system in the study, and thus can be used in structure investigation and HPV16 vaccine development.
Animals ; Antibodies, Viral ; immunology ; ultrastructure ; Capsid Proteins ; genetics ; immunology ; isolation & purification ; Goats ; Human papillomavirus 16 ; genetics ; immunology ; ultrastructure ; Humans ; Male ; Oncogene Proteins, Viral ; genetics ; immunology ; isolation & purification ; Papillomavirus Infections ; immunology ; virology ; Rabbits ; Recombinant Proteins ; genetics ; immunology ; Vaccination ; Virion ; genetics ; immunology

BACKGROUNDTo select the mutants of HPV type 16 E6 and E7 genes suitable for construction of vaccine for treatment of cervical cancer.

METHODSE6 and E7 genes were modified by site-directed mutagenesis. Several recombinant vaccina viruses were constructed by inserting the E6 or E7 mutants into the genome of vaccina virus Tiantan strain and employed to study their antigenicity.

RESULTSWestern blot assay showed that the E6 ?mutant? with substitution of Gly for Leu at amino acid site 50 and E7 mutant with substitution of Gly for Cys-24 and Glu-26 had no effect on their stability and antigenicity, but change of the Cys at position 91 of E7 dramatically reduced its stability and antigencity. Conclusion The results confirmed that the Zinc-finger structure at the E7 C-terminal? plays an important role in the integrity and stability of E7 protein.

Animals ; Antibodies, Viral ; biosynthesis ; Female ; Mice ; Mice, Inbred C57BL ; Mutagenesis, Insertional ; Oncogene Proteins, Viral ; genetics ; immunology ; Papillomaviridae ; genetics ; Papillomavirus E7 Proteins ; Repressor Proteins ; Vaccinia virus ; immunology ; Zinc Fingers

OBJECTIVETo compare humoral immune response by co-inoculating mice with antigen HPV16L1 virus-like particle (VLP) and HPV16L1 recombinant plasmids and then observing the neutralizing antibody activity in vitro.

METHODSC57BL/6 mice were injected intramuscularly/subcutaneously with pcDNA-L1 plasmids plus HPV16L1 VLP. Serum IgG levels were detected by ELISA, antibody neutralizing protective activities were determined by hemagglutination inhibition and HPV16L1 VLP binding inhibition assay.

RESULTSSerum antibody titers and neutralizing antibody activities were increased in HPV16L1 plasmids plus HPV16L1 VLP proteins in co-immunized mice when compared with controls.

CONCLUSIONCo-inoculation of the HPV16L1 VLP protein can enhance production of neutralizing antibody activities against aimed antigen, which should be a more promising strategy for effective HPV16 prophylactic vaccine development.

Animals ; Antibodies, Viral ; blood ; Capsid Proteins ; genetics ; immunology ; Erythrocyte Aggregation ; Genes, Viral ; HeLa Cells ; Human papillomavirus 16 ; genetics ; immunology ; Humans ; Immunization ; Immunoglobulin G ; blood ; Mice ; Mice, Inbred C57BL ; Neutralization Tests ; Oncogene Proteins, Viral ; genetics ; immunology ; Plasmids ; Recombinant Proteins ; immunology

OBJECTIVETo develop a recombinant vaccinia virus vaccine expressing HPV58 E7 and to determine its immuno-protective activity in mice bearing HPV58 E7+ tumor.

METHODSE7 DNA was amplified and cloned from a plasmid containing HPV58 E7 genome by PCR. To abolish its transforming activity, the nucleotides coding for amino acid residues at positions 24 and 92 were modified by site-directed mutagenesis so that cysteine was substituted by glycine. Balb/c 3T3 cells were transfected with mE7. The expression of E7 protein by the mE7-transfected Balb/c cells was confirmed by immunofluorescence staining. The transfected cells were observed in vitro for anchorage-independent growth and tumorigenesis in nude mice. Recombinant E7 vaccinia virus vaccine was constructed by homologous recombination of HPV58 E7 vaccinia expression plasmid and vaccinia virus (Tiantan stain). The immuno-protective activity of the vaccines was determined by tumor growth inhibition and cytotoxic T lymphocytes (CTL) induction in vaccine-immunized syngeneic mice.

RESULTSSubstitution of cysteine by glycine at both positions 24 and 92 of HPV58 E7 abolished its transforming activity. Growth of HPV E7+ tumor in mice immunized with the recombinant vaccinia virus expressing HPV58 E7 was inhibited, and the surviving time of the immunized mice was prolonged. CTL activity was induced as revealed by in vitro cytotoxicity assay using E7+ tumor cells as target cells.

CONCLUSIONSHPV58 E7, with its transforming potential abolished, may be used as vaccine for immunotherapy of patients with HPV 58 related cancers.

Animals ; Mice ; Mice, Inbred BALB C ; Mutagenesis, Site-Directed ; Oncogene Proteins, Viral ; genetics ; Papillomaviridae ; genetics ; immunology ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection ; Vaccines, Synthetic ; immunology ; Vaccinia virus ; genetics ; immunology

OBJECTIVETo construct recombinant adenovirus containing codon-modified HPV16L1 gene, and evaluate systemic and mucosal immunological responses induced after immunization with the recombinant virus.

METHODSThe recombinant adenovirus rAd-mod.HPV16L1 was constructed by Admax kit. The C57 BL/6 mice were immunized by purified rAd-mod.HPV16L1 through different inoculation routes. The immunological effect was evaluated by testing the specific neutralizing antibodies in sera and vaginal secretions of immunized mice through indirect ELISA and neutralization assay based HPV pseudovirus.

RESULTSThe result showed that intramuscular immunization could induce good systemic immunity, but the mucosal immunity was too weak, and immunization via intranasal route could induce satisfactory immunity both in sera and vaginal secretions, while intravaginal immunization failed to induce any specific immunological responses either in sera or vaginal secretions.

CONCLUSIONThe recombinant adenovirus containing codon- modified HPV16L1 gene was successfully constructed. Immunization through intranasal route could induce satisfactory immunity both in sera and vaginal secretions, while intramuscular immunization could only induce high titer of neutralizing antibodies in sera.

Adenoviridae ; genetics ; Animals ; Antibodies, Viral ; analysis ; immunology ; Antibody Specificity ; Capsid Proteins ; genetics ; immunology ; Codon ; genetics ; DNA, Recombinant ; genetics ; Female ; Genetic Engineering ; Human papillomavirus 16 ; genetics ; immunology ; Mice ; Mice, Inbred C57BL ; Oncogene Proteins, Viral ; genetics ; immunology ; Vaccination

Here, we presented a method to bacterially express the major structural protein L1 of Human Papillomavirus type 18 (HPV18) as soluble form. We found that the purified L1 could self-assemble to virus-like particles (VLPs). Further, we investigated the immunogenicity and the induced level of neutralizing antibody using these VLPs. First, the genome of HPV18 was cloned from a patient in Xiamen. It was used as template for PCR amplification of HPV18 L1 gene. The resultant DNA fragment was inserted into expression vector pTrxFus and expressed in Escherichia coli GI724. Second, L1 protein was purified by ammonium sulfate precipitation, ion-exchange chromatography and hydrophobic interaction chromatography; and the purified L1 was subjected to self-assembly to form VLPs with the removal of premixed reductant DTT. Finally, the size and morphology of these VLPs was investigated by Dynamic Light Scattering and Transmission Electronic Microscopy as 29.34 nm in hydrated radius and globular particles similar with native HPV18. The half effective dosage (ED50) and maximum level of neutralizing antibody elicitation were measured by vaccinations on mice, rabbit and goat using pseudovirus neutralization cell model. The results showed that the ED50 of HPV18 VLPs is 0.006 microg in mice, and the maximum titer of neutralizing antibody elicited in rabbit and goat is up to 10(7). As a conclusion, we can provide HPV18 VLPs with highly immunogenicity from prokaryote expression system, which may pave a new way for research and development of prophylactic vaccine for HPV18.
Animals ; Capsid Proteins ; biosynthesis ; genetics ; immunology ; Escherichia coli ; genetics ; metabolism ; Goats ; Human papillomavirus 18 ; immunology ; isolation & purification ; Mice ; Oncogene Proteins, Viral ; biosynthesis ; genetics ; immunology ; Rabbits ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Virion ; genetics ; immunology

Prokaryotic expression vector of mouse HPV16E6 gene was constructed. A pair of primers were designed according to the digestion sites in plasmid pGEX-KG and the HPV16E6 gene sequence published by GenBank. The DNA fragment of 321bp was amplified by PCR from the HPV recombinant plasmid with HPV16E6 gene, then cloned into pGEX-KG and transformed into the host E. coli strain JM109. The fragment was conformed to the original sequence, which indicated that fusion expression vector pGEX-KG-HPV16E6 was constructed. The pGEX-KG-HPV16E6 plasmid was taken and transformed into BL21(DE3) for expression. Induced by IPTG at 37 degrees C, the expression product of HPV16E6 gene was identified by SDS-PAGE and Western blot. HPV16E6 fusion protein had been expressed successfully in the form of inclusion bodies, the molecular weight of fusion protein being 38 kD. Meanwhile, the optimum condition of HPV16E6 fusion protein expression was induced with 1.0 mmol/L IPTG for 4h. The fusion protein reacted specifically with the antibodies against HPV16E6. HPV16E6 gene was successfully expressed in E. coli, which could be used as a basis for preparing HPV16E6 vaccine in human.
Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Glutathione Transferase ; biosynthesis ; genetics ; Humans ; Oncogene Proteins, Viral ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Repressor Proteins ; biosynthesis ; genetics ; Viral Vaccines ; immunology

To investigate the feasibility of using recombinant adeno-associated virus type 1 vector as prophylactic vaccine against HPV16 infection, rAAV1-mod. HPV16L1, the recombinant AAV1 vector containing codon-modified HPV16 L1 gene, was constructed. C57BL/6 mice were immunized with purified rAAV1 vector through intramuscular and intranasal inoculation routes, and the titer of neutralizing antibody was determined by neutralization assay based on HPV16 pseudovirus. The result shows that the single dose of rAAV1-mod. HPV16L1 can induce specific neutralizing antibody in serum through both inoculation routes. Compared with intranasal group, intramuscular group can induce higher titer of neutralizing antibody. Eliciting strong and prolonged neutralizing antibody in serum, the rAAV1-mod. HPV16L1 is one of promising HPV16 prophylactic vaccine candidates.
Animals ; Antibodies, Viral ; blood ; Capsid Proteins ; genetics ; immunology ; Dependovirus ; genetics ; Female ; Mice ; Mice, Inbred C57BL ; Oncogene Proteins, Viral ; genetics ; immunology ; Papillomavirus Vaccines ; administration & dosage ; immunology ; Vaccination ; Vaccines, Synthetic ; administration & dosage ; immunology

OBJECTIVE: To determine the relationship between serum antibody against HPV16 E4 and cervical cancer, and to construct HPV 16 E4 protein expression vector as an antigen to detect its corresponding serum antibody among different populations. METHODS: HPV16 E4 early gene was ligated into pRSET-A expression vector. The constructed plasmids were transformed into BL21 (DE3)cells, and induced to express HPV 16 E4 protein by isopropylthio-beta-D-galactoside (IPTG). The expressed E4 inclusions were denatured, purified through Ni-column, and renatured. After the activity was revealed, antibodies against HPV 16 E4 in the sera from healthy women and patients with chronic cervicitis and cervical cancer were respectively determined by enzyme-linked immunosorbent assay (ELISA) using the fusion protein as the antigen. RESULTS: HPV 16 E4 fusion protein of Mr 15*10(3) was expressed by pRSET-16E4 after IPTG induction. The fusion protein accounted for 30% of the total bacterial proteins and expressed as inclusive body. After purification with Ni-NTA agarose resin, the recombinant protein revealed purity of 95%, and activity of the renatured protein was identified by ELISA. The serum antibody-positive rate of HPV 16 E4 was 10.00%, 39.13% and 28.13%, respectively in 80 healthy women, 46 chronic cervicitis patients, and 32 cervical cancer patients. The antibody-positive rate in cervical cancer patients and chronic cervicitis patients were significantly higher than that in healthy women (P<0.01), while the difference between the antibody-positive rate in cervical cancer patients and chronic cervicitis patients was not significant. CONCLUSION HPV 16 E4 protein expressed from pRSET-A/BL21 can be used in serological studies on cervical cancer-related HPV infection. Serum antibody against HPV16 E4 is present in a significantly higher percentage in cervical cancer and chronic cervicitis patients than in healthy women.
Adult ; Aged ; Antibodies, Viral ; blood ; Female ; Genetic Vectors ; Human papillomavirus 16 ; genetics ; immunology ; Humans ; Middle Aged ; Oncogene Proteins, Viral ; biosynthesis ; genetics ; immunology ; Papillomavirus Infections ; immunology ; virology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Uterine Cervical Neoplasms ; immunology ; virology ; Uterine Cervicitis ; virology

OBJECTIVETo develop a therapeutic vaccine against human tumors associated with human papillomavirus type 16E6E7 (HPV16E6E7) which is modified from a Chinese patient of the cervical cancer which possessing the antigenicity and no transforming activity, and explore more active vaccine for inducing cellular immunity with mouse co-stimulatory molecular B7-1 gene.

METHODSThe modified E6E7 gene expression plasmid pVR1012-fmE6E7 was constructed and transfected Cos-7 cells, and the E7 protein specific expression was testified by immunofluorescence assay. C57BL/6 mice were immunized intramuscularly with pVR1012-fmE6E7 alone or in combination with B7-1 gene expression plasmid (pcDNA3.1-B7-1). The activity of cytotoxic T lymphocytes (CTLs) was analyzed with 51Cr specific release assay and the specific antibody in sera was analyzed by indirect ELISA. HPV16 positive C57BL/6 tumor cells C3 were inoculated subcutaneously in the vaccinated mice to assay the growth of transplanted tumors.

RESULTSThe specific CTLs and antibody from immunized mice were induced efficaciously by the E6E7 gene immunization, and co-administration of B7-1 gene could significantly enhanced the CTLs immune responses of fmE6E7, and protected 33% immunized mice against C3 tumor cells challenge. In contrast, all the mice immunized only with fmE6E7 gene developed transplanted tumors after C3 cells challenge. There was no difference in E7 specific antibody responses between mice immunized with the E6E7 gene only and co-administration with B7-1 gene.

CONCLUSIONSThe modified E6E7 gene can be used as target gene for developing DNA vaccine, and B7-1 gene may represent an attractive adjuvant for enhancement of the specific cellular immune responses.

Animals ; Antibodies, Neoplasm ; immunology ; B7-1 Antigen ; genetics ; immunology ; Female ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Oncogene Proteins, Viral ; genetics ; immunology ; Papillomavirus E7 Proteins ; Repressor Proteins ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection ; Uterine Cervical Neoplasms ; immunology ; pathology ; virology ; Vaccines, DNA ; immunology