This study was intended to establish a method of purification of HPV16 L1 protein expressed in a prokaryotic system and to obtain the purified protein. The prokaryotic expression vector pGEX-4T-1-HPV16 L1 was constructed and transformed into E. coli BL21 cell, and induced by 1 mM IPTG to express HPV16L1 protein. The inclusion bodies were isolated and solubilized with 8 M urea. After the urea was removed by gradual dialysis, the denatured L1 protein were renatured and then were purified by affinity chromatography. The results showed that HPV16L1 protein formed inclusion bodies in bacterial expression system, suggesting that this assay can be used to purify HPV16L1 protein and hence provide a basis for studying the applications of HPV16 L1 protein.
Capsid Proteins ; biosynthesis ; Escherichia coli ; metabolism ; Genetic Vectors ; Human papillomavirus 16 ; Oncogene Proteins, Viral ; biosynthesis

OBJECTIVETo express the L1 protein of human papillomavirus type 16 (HPV16) in insect cell suspension culture system.

METHODSOptimized the conditions of suspension culture, recombinant virus amplification and protein expression. Determined the virus tilter by plague analysis and detected the target protein by SDS-PAGE and Western blot; The formation of VLPs by HPV16 L1 protein was observed with TEM.

RESULTSThe Sf9 cells could grow better in suspension culture with seeding density of 5 x 10-5 cell/mL and the maximum expression quantity was obtained by infection of cells with rBacV/HPV16L1 (MOI =10) and harvesting after 72-84 h. HPV16L1 protein could assemble into VLPs in Sf9 cells observed with TEM.

CONCLUSIONThe conditions of cell culture, virus amplification and protein expression were optimized. HPV16 L1 protein could assemble into VLPs in Sf9 cells, which would provide a foundation for further study of the vaccine and diagnosis kits.

Animals ; Capsid Proteins ; biosynthesis ; Cell Proliferation ; Oncogene Proteins, Viral ; biosynthesis ; Recombinant Proteins ; biosynthesis ; Spodoptera ; Suspensions ; Virion ; ultrastructure

To explore the molecular mechanism of human papillomavirus subtype 16(HPV-16)E7 oncogene-induced DNA re-replication in response to DNA damage. Flow cytometry was performed to examine the cell cycle changes in RPE1 E7 cells stably expressing HPV-16 E7 and its control cell RPE1 Vector after DNA damage.Immunoblotting assay was used to evaluate the early mitotic inhibitor 1(Emi1)expression in RPE1 E7 and RPE1 Vector cells with or without DNA damage.The changes of the proportion of polyploidy was detected by flow cytometry in DNA-damaged RPE1 E7 cells interfered by Emi1 small interfering RNA. Compared with the control cells,the proportion of polyploids in RPE1 E7 cells was significantly increased in response to DNA damage(=6.397,=0.0031).Emi1 protein expression was significantly increased in DNA damaged RPE1 E7 cells(=8.241,=0.0012).The polyploid ratio of RPE1 E7 cells was significantly reduced after Emi1 was interfered by two independent small interfering RNAs(=2.916,=0.0434;=3.452,=0.0260). In response to DNA damage,Emi1 promoted DNA re-replication caused by HPV-16 E7.
DNA Damage ; DNA Replication ; Human papillomavirus 16 ; Mitosis ; Oncogene Proteins, Viral

OBJECTIVETo establish an immortalized oral epithelial cell line.

METHODSNormal human oral epithelial cells were transfected with HPV16E6/E7 open reading frames using recombinant retroviral system pLXSN. Expression of HPV16E6 and E7 protein were tested by Western blot in three kinds of cells. To define cellular biological characterization of HPV16E6/E7 transfected cells, a series analysis were performed, including protraction of growth curve, HE staining, immunocytochemical staining and scanning electron microscope observation. The tumorigenicity was assessed by colony formation and transplanting the cells into nude mice.

RESULTSHuman oral epithelial cells transfected with HPVE6/E7 has been in culture for over 18 months. The cell line was named HIO615. Western blot analysis showed HIO615 expressed HPV16 E6 and E7 protein. HIOC were positive for cytokeratin, tonofibril and desmosome as observed by scanning electron microscope. The number of large colonies of dense multilayer cells was low (0.77%). No tumor developed in nude mice injected subcutaneously with HIOEC.

CONCLUSIONA human immortalized oral epithelial cell line induced by HPV16E6 and E7 has been successfully established.

Animals ; Cell Line, Transformed ; Cell Transformation, Viral ; Humans ; Mice ; Mice, Inbred BALB C ; Mouth Mucosa ; cytology ; ultrastructure ; virology ; Oncogene Proteins, Viral ; genetics ; Papillomavirus E7 Proteins ; Repressor Proteins

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

OBJECTIVE: To investigate the molecular mechanism of Wnt5a and Epstein-Barr virus latent membrane protein 1 (LMP1) aberrant expression in the nasopharyngeal carcinogenesis and to estimate if it can act as a molecular marker for nasopharyngeal cancer (NPC). METHODS: Immunohistochemistry combined with previously made tissue microarrays were used to study the expression of Wnt5a and LMP1 in the nasopharyngeal carcinogenesis tissues. We investigated the role of over expression of Wnt5a and LMP1 in the development and progression of NPC and their relation with the clinicopathological features of NPC and whether they could act as molecular markers in benign and malignant NPC. RESULTS: The positive percentage of Wnt5a and LMP1 protein expression in the NPC was significantly increased as compared with that in atypically hyperplastic nasopharyngeal epithelium, hyperplastic nasopharyngeal epithelium and histologically normal nasopharyngeal epithelium (P<0.05, P<0.01, and P<0.01). Wnt5a and LMP1 proteins were significantly higher in atypically hyperplastic nasopharyngeal epithelium than those in the hyperplastic nasopharyngeal epithelium and normal nasopharyngeal epithelium (P<0.05 and P<0.01). The positive expression of Wnt5a and LMP1 proteins in clinical T3 and T4 staged NPC was higher than that in clinical T1 and T2 staged NPC (P<0.01 and P<0.05). The positive expression of Wnt5a protein in the NPC with lymph node metastasis was higher than that in the NPC without lymph node metastasis (P<0.01). The positive percentage of LMP1 protein was significantly increased in non-keratinizing carcinoma compared with undifferentiated carcinoma and keratinizing carcinoma (P<0.05 and P<0.05). The expression of Wnt5a protein in the NPC had significant positive correlation with LMP1 (r=0.354, P<0.001). Combined molecular phenotype of both Wnt5a and LMP1 expression was a good marker to distinguish NPC from non-cancerous nasopharyngeal epithelium. CONCLUSION The expression of Wnt5a and LMP1 protein in the NPC is positively correlated, and both wnt5a and LMP1 protein play important roles in the nasopharyngeal carcinogenesis either together or successively promoting the malignant transformation of nasopharyngeal epithelium and the development and progression of NPC. Both Wnt5a and LMP1 positive expression may act as good markers for NPC differential diagnosis.
Biomarkers, Tumor ; genetics ; metabolism ; Carcinogenesis ; Humans ; Nasopharyngeal Neoplasms ; genetics ; metabolism ; pathology ; Oncogene Proteins, Viral ; genetics ; metabolism ; Proto-Oncogene Proteins ; genetics ; metabolism ; Tissue Array Analysis ; Viral Matrix Proteins ; genetics ; metabolism ; Wnt Proteins ; genetics ; metabolism ; Wnt-5a Protein

Human papilloma virus (HPV) is believed to be an essential factor for the development of cervical cancer. Early diagnosis and treatment of cervical intraepithelial neoplasia can effectively inhibit the future progression. HPV late 1 protein possesses epitope that can identify and adhere to host cells, and thus may play an important role in HPV infection and cervical carcinogenesis.
Capsid Proteins ; Cervix Uteri ; metabolism ; virology ; Female ; Humans ; Oncogene Proteins, Viral ; Papillomavirus Infections ; complications ; Uterine Cervical Neoplasms ; virology

BACKGROUNDHeat shock protein 70 (HSP70) is expressed highly in epithelial tumours associated closely with human papillomavirus 16 (HPV16) infections. However, evidence about the direct relationship between HSP70 expression and HPVs infections are still lacking. In the present study, we examined the expression of HSP70 in keratinocytes introduced with HPV16 E6/E7 oncogenes.

METHODSStable transfected cells were established by transfection of the plasmids pLXSN16E6/E7 into cultured primary keratinocytes and subsequently selected by plasmid specific selection antibiotic (G418) at the required concentration. The expression of HSP70 in pLXSN16E6/E7 transfected keratinocytes was determined by Western blot. The correlation of HSP70 expression and E6/E7 transfection was further confirmed by doubly labelled immunofluorescent staining.

RESULTSCompared to non-transfected keratinocytes, there was a significant trend for higher levels of HSP70 in pLXSN16E6/E7 transfected keratinocytes. Doubly labelled immunofluorescent staining experiment showed that the co-localization of HPV16 E6/E7 and HSP70 in transfected keratinocytes was observed and increased expression of HSP70 was strongly associated with the transfection of HPV16 E6/E7.

CONCLUSIONSOur studies demonstrated increased levels of HSP70 proteins in keratinocytes stably transfected by HPV16 E6/E7 oncogenes. It suggests that the expression of HSP70 is modulated by HPV16 E6/E7 proteins, which may be involved in HPV16 E6/E7 induced immortalization.

Cells, Cultured ; HSP72 Heat-Shock Proteins ; biosynthesis ; Humans ; Keratinocytes ; metabolism ; Oncogene Proteins, Viral ; genetics ; Papillomavirus E7 Proteins ; Repressor Proteins ; genetics ; Transfection

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

To investigate whether a conserved sequence of the human papillomavirus(HPV) L1 protein consisted of 12 amino acid residue can induce the antibody aimed at multiple HPV types, we screened a conserved sequence of the HPV L1 protein by forecasting B cell epitope and comparing multiple sequences. The peptide was synthesized, mixed with Freund adjuvant, and used to immunize rabbits, and those in the control group were only immunized with Freund adjuvant. Then the antibody titer was identified by indirect enzyme-linked immunosorbent assay (ELISA). And immunocytochemistry, immunofluorescence, western blot and immunohistochemistry were used to detect whether the antibody could react with cervical cancer cell lines and cervical tissue that had been identified with HPV infections. We found that the antibody titer was greater than 1:25600. Moreover, we confirmed that the antibody could react with cervical cancer cell lines and cervical tissue with HPV infections. The results showed that the peptide could induce antibody aimed at multiple HPV types. Our findings have great significance in further research of the broad spectrum HPV, HPV L1 diagnosis kits.
Animals ; Antibodies, Viral ; immunology ; B-Lymphocytes ; immunology ; Capsid Proteins ; classification ; immunology ; Computer Simulation ; Epitopes ; immunology ; Female ; HeLa Cells ; Humans ; Oncogene Proteins, Viral ; classification ; immunology ; Papillomaviridae ; immunology ; Papillomavirus Infections ; immunology ; Rabbits ; Viral Proteins ; immunology