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

Epidermodysplasia verruciformis (EV), a rare inherited disease, is believed to be associated with human papillomavirus (HPV) infection. EVER1/2 genes, dendritic cells, T lymphocytes, and the biological characteristics of HPV itself may play roles in the pathogenesis of HPV infection.
Dendritic Cells ; immunology ; Epidermodysplasia Verruciformis ; genetics ; immunology ; virology ; Humans ; Membrane Proteins ; genetics ; Mutation ; Papillomaviridae ; isolation & purification ; pathogenicity ; Papillomavirus Infections ; complications ; T-Lymphocytes ; 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 express HPV31 and 52 L2 fusion protein and detect its immunogenicity.

METHODSAccording to the amino acid sequences of HPV31 and 52 L2 11-200AA published in the GenBank database, weartificially synthesized the HPV31 and 52 L2 fusion gene which was optimized according to Escherichia coli codon usage and encodes 11-200 amino acid of HPV31 and HPV52 L2, then cloned it into pET-9a vector. The HPV31 and 52 L2 fusion protein was expressed in Prokaryotic expression system and the mice were immunized with the fusion protein after purification. The immunogenicity was characterized in vaccinated mice.

RESULTSHPV31 and 52 L2 fusion protein was highly expressed in E. coli, the amount of fusion protein is nearly 20% of the total bacterial protein. The purified fusion protein with aluminum adjuvant could induce specific high titer of IgG antibodies detected by ELISA, and also induce the neutralizing antibodies against pseudovirus of HPV31 and HPV52 and cross-neutralizing antibodies against pseudovirus of HPV45, 58, 16, 18.

CONCLUSIONHPV31 and 52 L2 fusion protein could induce neutralizing and cross-neutralizing antibodies against HPV pseudovirus. It provides laboratory basis for development of HPV L2 protein vaccine.

Animals ; Antibodies, Viral ; blood ; Escherichia coli ; genetics ; Female ; Mice ; Mice, Inbred BALB C ; Oncogene Proteins, Viral ; genetics ; immunology ; Papillomaviridae ; immunology ; Papillomavirus Vaccines ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; immunology ; isolation & purification

Prevention of infection by the human papillomavirus (HPV) has become a hot research topic since the relationship between the HPV and cervical cancer was confirmed. Persistent infection with HPV and early expression of proteins has an important role in the pathogenesis of cervical cancer. Vaccines that protect against four high-risk types of HPV (-6, -11, -16, -18) have been used worldwide. A bivalent vaccine (HPV-16 and -18) developed by Walvax is in clinical trials. This study reviews progress in ascertainment of the structure and function of the HPV genome, the molecular mechanism of carcinogenesis, and vaccines based on virus-like particles.
Animals ; Carcinogenesis ; Female ; Humans ; Papillomaviridae ; genetics ; immunology ; metabolism ; Papillomavirus Infections ; pathology ; prevention & control ; virology ; Papillomavirus Vaccines ; genetics ; immunology ; Uterine Cervical Neoplasms ; pathology ; prevention & control ; virology ; Viral Proteins ; genetics ; immunology ; metabolism

To prepare carboxyl terminus truncated human papillomavirus type 58L1 protein, and study on its in vitro bioactivity. PCR was used to amplify carboxyl terminus truncated HPV 58L1 gene, the product was inserted into the PUCMT cloning vector, preparing recombinant PFastBacHTb containing carboxyl terminus truncated HPV58L1 gene. Further more, the recombinant plasmid PfastbacHTb was used to transform DH10Bac cells, constructing recombinant Baculovirus, then the recombinant virus was successfully used to infect Sf-9 insect cells. After incubating at 27 degrees C for 72 hours, the infected cells were collected and total cellular proteins were extracted. The target protein with MW 58KD was revealed by SDS-PAGE and confirmed by Western blot. The interested protein was purified by ProBond purification system. The purified interested protein was identified to self-assemble into VLPs by Transmission electron microscope, and induce murine erythrocyte hemagglutination, indicating that the given proteins had the conformation of VLPs, collecting, HPV58L1 proteins with carboxyl terminus truncation could be efficiently expressed in baculovirus Sf-9 cells expression system, it has identical in vitro bioactivity to the wild type HPV58L1, The present study is fundmental for preparing HPV58L1 prophylactic vaccine.
Animals ; Baculoviridae ; genetics ; Blotting, Western ; Cloning, Molecular ; Humans ; Mice ; Mice, Inbred C57BL ; Papillomaviridae ; genetics ; Papillomavirus Vaccines ; immunology ; Recombinant Proteins ; biosynthesis ; isolation & purification ; Vaccines, Synthetic ; immunology ; Viral Proteins ; biosynthesis ; genetics ; Virion ; immunology

OBJECTIVETo generate a candidate HPV16 vaccine for experimental and therapeutical use for cervical cancer.

METHODSThe mutants of HPV16 early E6 and E7 genes were inserted into a vaccinia virus expression vector. A strain of recombinant vaccinia virus was constructed through homologous recombination.

RESULTSShowed that the mutant E6 and E7 genes were located at TK gene region of vaccinia virus Tiantan strain in a head to head orientation under the control of early/late promoters, H6 and 7.5K respectively. Studies in mice indicated that VmE6E7 could elicit specific antibodies against E6 and E7, and retarded or prevented tumor development in a proportion of C57 BL/6 mice challenged by syngeneic HPV16E6 and E7 transformed tumor cells.

CONCLUSIONSThe success in constructing VmE6E7 provides a basis for the further development of HPV16 therapeutic vaccine.

Animals ; Female ; Genes, Viral ; genetics ; Genetic Vectors ; genetics ; immunology ; Mice ; Mice, Inbred C57BL ; Mutation ; Neoplasms, Experimental ; prevention & control ; Oncogene Proteins, Viral ; genetics ; Papillomaviridae ; genetics ; Papillomavirus E7 Proteins ; Recombination, Genetic ; Repressor Proteins ; Transfection ; Vaccinia virus ; genetics ; immunology

OBJECTIVETo analyze the influence of optimal codon usage on the expression levels and immunogenicity of DNA vaccines, encoding the human papillomavirus type 6b (HPV 6b) E7 gene.

METHODSThe full length E7 gene of HPV 6b was modified to substitute human preferred codon for rarely used codon, and three mutations were introduced into the pRB binding site of HPV 6b E7 to eliminate its transformation potential. The codon optimized and mutated E7 gene (hu-mE7) were cloned into the Kpn I and EcoR I site of the pcDNA3 mammalian expression vector, the in vitro expression of the hu-mE7 gene and the immunogenicity of hu-mE7 DNA vaccine were compared with the wt-E7gene.

RESULTSThe in vitro expression of pcDNA3-hu-mE7 was much higher than the classical wt-E7 plasmid in monkey COS-1 cell line. Mice immunized intramuscularly with the pcDNA3-hu-mE7 showed that the codon modified E7 gene induced a stronger IFN-gamma ratios than the wt-E7 gene.

CONCLUSIONSThese results suggest that the optimized codon usage contributes to the enhancement of gene expression and immunogenicity of HPV 6b E7 gene.

Animals ; Cell Line ; Codon ; genetics ; Female ; Gene Expression ; Genes, Viral ; genetics ; Genetic Vectors ; Mice ; Papillomaviridae ; genetics ; Papillomavirus Vaccines ; Transfection ; Vaccines, DNA ; immunology ; Viral Proteins ; biosynthesis ; genetics ; Viral Vaccines ; immunology

More than 99% of cervical cancers have been associated with human papillomaviruses (HPVs), particularly HPV type 16. The clear association between HPV infection and cervical cancer indicates that HPV serves as an ideal target for development of preventive and therapeutic vaccines. Although the recently licensed preventive HPV vaccine, Gardasil, has been shown to be safe and capable of generating significant protection against specific HPV types, it does not have therapeutic effect against established HPV infections and HPV-associated lesions. Two HPV oncogenic proteins, E6 and E7, are consistently co-expressed in HPV-expressing cervical cancers and are important in the induction and maintenance of cellular transformation. Therefore, immunotherapy targeting E6 and/or E7 proteins may provide an opportunity to prevent and treat HPV-associated cervical malignancies. It has been established that T cell-mediated immunity is one of the most crucial components to defend against HPV infections and HPV-associated lesions. Therefore, effective therapeutic HPV vaccines should generate strong E6/E7-specific T cell-mediated immune responses. DNA vaccines have emerged as an attractive approach for antigen-specific T cell-mediated immunotherapy to combat cancers. Intradermal administration of DNA vaccines via a gene gun represents an efficient way to deliver DNA vaccines into professional antigen-presenting cells in vivo. Professional antigen-presenting cells, such as dendritic cells, are the most effective cells for priming antigen-specific T cells. Using the gene gun delivery system, we tested several DNA vaccines that employ intracellular targeting strategies for enhancing MHC class I and class II presentation of encoded model antigen HPV-16 E7. Furthermore, we have developed a strategy to prolong the life of DCs to enhance DNA vaccine potency. More recently, we have developed a strategy to generate antigen-specific CD4+ T cell immune responses to further enhance DNA vaccine potency. The impressive pre- clinical data generated from our studies have led to several HPV DNA vaccine clinical trials.
Female ; Humans ; Oncogene Proteins, Viral/genetics/immunology ; Papillomaviridae/*genetics/immunology ; Papillomavirus Infections/immunology/*prevention & control ; Papillomavirus Vaccines/*administration & dosage ; Repressor Proteins ; Uterine Cervical Neoplasms/*prevention & control ; Vaccines, DNA/*administration & dosage ; Viral Vaccines/administration & dosage

OBJECTIVETo develop a prophylactic and therapeutic vaccine against human papillomavirus (HPV) type 58-associated cervical carcinoma, and explore its transformation activity and antigenicity.

METHODSThe E6 and E7 three amino acid codons in the HPV 58 virus were modified respectively and fused. The modified and fused gene was named HPV58 mE6E7. The recombinant HPV58 mE6E7 gene was inserted into pIRES-neo vector to generate plasmid pIRES-neo-HPV58 mE6E7. Then NIH/3T3 cell line was transfected with plasmid pIRES-neo-HPV58 mE6E7. The pIRES-neo-HPV58 mE6E7-transfected cells were the experimental group, pIRES-neo-HPV58 E6E7-transfected cells were the positive control group, and pIRES-neo empty vector-transfected cells were the negative control group. The expression of HPV58 mE6E7 protein in the experimental cells was detected by flow cytometry, immunofluorescence and Western blot. The transformation activity of HPV58 mE6E7 was tested by soft agar colony formation assay and subcutaneously tumors in nude mice. Finally, DNA vaccine was constructed with HPV58 mE6E7 fusion antigen and used to immunize C57BL/6 mice with the vaccine plasmids. The specific serum antibodies were detected by EIISA, and the number of splenic specific CD8(+) T cells secreting IFN-γ of the immunized mice was detected by ELISPOT assay.

RESULTSSequencing confirmed the expected mutation and a 100% homogeneity of the HPV58 E6E7 fusion gene. Stable transfected NIH/3T3 cells expressing HPV58 mE6E7 and HPV58 E6E7 gene were 70.3% and 84.1%, respectively. The relative expressions of HPV58 mE6E7 and HPV58 E6E7 fusion protein in 3T3-HPV58 mE6E7 experimental cells and 3T3-HPV58 E6E7 positive control cells were 2.1 ± 1.7 and 3.8 ± 1.4, respectively, and were negative in the negative control group. No colony formation was found in the experimental and 3T3-neo negative control cell groups, and 31 colonies were found in the positive control cell group, among them 10 colonies were consisted of more than 50 cells. No tumor mass was formed within 4 weeks in the nude mice of experimental and negative control groups, but among the 10 mice of positive control group tumor was formed in 6 mice. Using HPV58 mE6E7 fusion gene as target antigen of DNA vaccine, the antibody titer was 25 600, and specific immunity spots were 218.8 ± 34.4, significantly higher than that in the control group.

CONCLUSIONSThe fused and modified HPV58 E6E7 amino acid codons can abolish the transformation activity but preserve its antigenicity. HPV58 mE6E7 is a potential target gene for the development of therapeutic DNA vaccine against HPV58-associated cervical cancer.

Animals ; Cancer Vaccines ; immunology ; Capsid Proteins ; genetics ; immunology ; Cell Transformation, Neoplastic ; Cloning, Molecular ; Codon ; Female ; Immunoglobulin G ; metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Mice, Nude ; NIH 3T3 Cells ; Oncogene Proteins, Viral ; genetics ; immunology ; Papillomaviridae ; Papillomavirus E7 Proteins ; genetics ; immunology ; Papillomavirus Vaccines ; immunology ; Plasmids ; Point Mutation ; Random Allocation ; Recombinant Fusion Proteins ; genetics ; immunology ; Transfection ; Vaccines, DNA ; immunology