Penile cancer associated with so-called low-risk human papilloma virus. Report of five cases from rural Venezuela

Penile cancer is uncommon in western countries. It has been related to human papilloma virus (HPV) types 16 and 18. We describe five cases of carcinoma of the penis in men from a rural Venezuelan town that were related to HPV types 6, 11, 53, which represent a rather low risk for cancer.

Simultaneous detection and differentiation of human papillomavirus genotypes 6, 11, 16 and 18 by AllGlo quadruplex quantitative PCR

Background

Human papillomaviruses (HPV) are classified into high-risk HPV and low-risk HPV. The most common high-risk HPV types in cervical cancer are HPV 16 and 18, and the most common low-risk types causing genital warts are HPV 6 and HPV 11. In this study, applying novel AllGlo fluorescent probes, we established a quadruplex quantitative PCR method to simultaneously detect and differentiate HPV 6, 11, 16 and 18 in a single tube.

Methods

The specificity, the sensitivity, the detection limit, the reproducibility and the standard curve of this method were examined. Finally, clinical samples that had been tested previously by TaqMan PCR and HPV GenoArray (GA) test were used to verify the accuracy and sensitivity of the method.

Results

The assay has a sensitivity of 10¹ to 10² copies/test and a linear detection range from 10¹ to 10⁸ copies/test. The mean amplification efficiencies for HPV 6, 11, 16, and 18 were 0.97, 1.10, 0.93 and 1.20, respectively, and the mean correlation coefficient (r²) of each standard curve was above 0.99 for plasmid templates ranging from 10³ to 10⁷ copies/test. There was 100% agreement between the AllGlo quadruplex quantitative PCR, HPV GA test and TaqMan uniplex qPCR methods.

Conclusions

AllGlo quadruplex quantitative PCR in a single tube has the advantages of relatively high throughput, good reproducibility, high sensitivity, high specificity, and a wide linear range of detection. The convenient single tube format makes this assay a powerful tool for the studies of mixed infections by multiple pathogens, viral typing and viral load quantification.

Classification and nomenclature system for human Alphapapillomavirus variants: general features, nucleotide landmarks and assignment of HPV6 and HPV11 isolates to variant lineages

BACKGROUND

Papillomaviruses constitute a family of viruses that can be classified into genera, species and types based on their viral genome heterogeneity. Currently circulating infectious human Alphapapillomaviruses (alpha-PVs) constitute a set of viral genomes that have evolved from archaic times and display features of host co-speciation. Viral variants are more recently evolved genomes that require a standardized classification and nomenclature.

OBJECTIVES

To describe a system for the classification and nomenclature of HPV viral variants and provide landmarks for the numbering of nucleotide positions.

METHODS

The complete 8 kb genomes of the alpha-9 species group and HPV6 and 11 types, collected from isolates throughout the world were obtained from published reports and GenBank. Complete genomes for each HPV type were aligned using the E1 start codon and sequence divergence was calculated by global and pairwise alignments using the MUSCLE program. Phylogenetic trees were constructed from the aligned sequences using a maximum likelihood method (RAxML).

RESULTS

Pairwise comparisons of nucleotide differences between complete genomes of each type from alpha-9 HPV isolates (HPV16, 31, 33, 35, 52, 58 and 67) revealed a trimodal distribution. Maximum heterogeneity for variants within a type varied from 0.6%-2.3%. Nucleotide differences of approximately 1.0%-10.0% and 0.5%-1.0% of the complete genomes were used to define variant lineages and sublineages, respectively. Analysis of 43 HPV6 complete genomes indicated the presence of 2 variant lineages, whereas 32 HPV11 isolates were highly similar and clustered into 2 sublineages. A table was constructed of the human alpha-PV landmark nucleotide sequences for future reference and alignments.

CONCLUSIONS

A proposed nomenclature system for viral variants and coordination of nucleotide positions will facilitate the comparison of variants across geographic regions and amongst different populations. In addition, this system will facilitate study of pathogenic, tissue tropism and functional differences amongst variant lineages of and polymorphisms within HPV variants.

[Expression, purification and immunogenicity of human papillomavirus type 11 virus-like particles from Escherichia coli]

OBJECTIVE

To produce human papillomavirus type 11 virus-like particles (HPV11 VLPs) from Escherichia coli and to investigate its immunogenicity and type cross neutralization nature.

METHODS

We expressed the major capsid protein of HPV11 (HPV11-L1) in Escherichia coli ER2566 in non fusion fashion and purified by amino sulfate precipitation, ion-exchange chromatography and hydrophobic interaction chromatography, sequentially. Then we removed the reductant DTT to have the purified HPV11-L1 self-assemble into VLPs in vitro. We investigated the morphology of these VLPs with dynamic light scattering and transmission electron microscopy. We assayed the immunogenicity of the resultant HPV11 VLPs by vaccinations on mice and evaluated by HPV6/11/16/18 pseudovirion neutralization cell models.

RESULTS

We expressed HPV11 L1 in Escherichia coli with two forms, soluble and inclusion body. The soluble HPV11 L1 with over 95% purity can self assemble to VLPs in high efficiency. Morphologically, these VLPs were globular, homogeneous and with a diameter of - 50 nm, which is quite similar with native HPV11 virions. The half effective dosage (ED50) of HPV11 VLPs is 0.031 microg, and the maximum titer of neutralizing antibody elicited is averaged to 10(6). The cross neutralization activity (against HPV6/16/18) of the anti-HPV11 serum was found to have exact correlation to the inter-type homology in amino acid alignment.

CONCLUSION

We can provide HPV11 VLPs with highly immunogenicity from prokaryote expression system, which may pave a new way for research and development of prophylactic vaccine for HPV11.

[Study on the genotyping of human papillomavirus using a new DNA liquid chip in women of high-risk group of Shandong province]

OBJECTIVE

To evaluate the diagnostic applicability of human papillomavirus (HPV) liquid chip assay which is based on Luminex XMAP System, and perform a HPV epidemiologic study with the liquid chip in women of Shandong province.

METHODS

To detect HPV genotypes on a 96-well plate with the liquid chip which can simultaneously detect and identify 26 common HPV genotypes in a total of 2925 cervical scrapes obtained from gynecological outpatients as well as to analyze the relationship between HPV types and different cervical diseases by studying the distribution of HPV genotypes and pathologic diagnosis.

RESULTS

Among 639 cases who performed pathologic/cytological and histological diagnoses, 184 cases are in group of normal cytology, 266 cases in group of, 77 cases in group of cervical intra-epithelial neoplasia (CIN) I, 7 cases in group of CIN I - II, 46 cases in group of CIN I - II, 46 cases in group of CIN I - II and 13 cases in group of cervical cancer. The overall incidence of HPV in our samples is 36.0% (1054/2925) and 23 types of all 26 types on liquid chip are found. The most common genotypes found are HPV-16 (26.75%), HPV-52 (25.75%), HPV-58 (10.47%), HPV-18 (8.87%) and HPV-11 (6.94%). Among all the positive types, 87.32% are high-risk HPV and 13.68% are low-risk HPV genotypes. Both single and multiple types are easily identified, showing 66.22% ( n = 698) single type and 33.78% ( n = 356) multiple types. Of all the 1054 HPV-positive cases, 261 (24.8%) is occupied by women 21 to 25 years of age and progressively lower by older age groups, reaching 4.9% by women between 51 to 67 years old. The incidence of HPV in our samples is 23.37%, 33.08%, 54.54%, 57.14%, 82.61%, 91.30% and 100% for normal cytology, inflammation,CIN I ,CIN I - II, CIN II ,CIN III, and carcinomas specimens, respectively. Infections with more that one virus are common, accounted for 4.89%, 7.14%, 18.18%, 28.57%, 41.30%, 43.37% and 38.46% for normal cytology, inflammation, CIN I, CIN I - II, CIN II, CIN III, and carcinomas specimens, respectively. Based on the criteria of histology and pathology, the sensitivity, specificity, positive-predictive value and negative-predictive value of HPV liquid chip assay for detecting all cases of CIN II, III are 88.57%, 76.63%, 68.89% and 92.16% respectively. Conclusion The common types of HPV infection are 16, 52, 58, 18, 11, 6, 56 and 31. The HPV-positive rate increased along with the increase of grading on cervical lesions. There are more younger women among all the HPV-positive ones. Multiplex HPV genotyping by liquid chip appears to be highly suitable for diagnostic screening as well as the conduction of large-scale epidemiological studies.