A comparative sequence analysis of two human papillomavirus (HPV) types 2a and 57

HPV 2a is commonly associated with verrucae vulgares, whereas HPV 57 was detected in mucosal lesions of the maxillary sinus and the genital tract, as well as in cutaneous lesions. The complete DNA sequences of HPV 2a and HPV 57 were determined. The HPV 2a genome consists of 7860 base pairs and the HPV 57 genome contains 7861 base pairs. On the nucleotide level an 83% homology between the two sequences could be ascertained. Compared to other HPVs they have a high G/C-content (HPV 2a: 48.8%, HPV 57: 50.1%). The genomic organization of both viruses complies with that of other sequenced HPVs. Significant sequence divergence between the HPV 2a and HPV 57 genomes was found in the long control region (LCR), as well as in the early-late-region (ELR). The latter varies in size between the cutaneous (72 to 103 nucleotides) and the mucosal HPVs (252 to 584 nucleotides). According to the sizes of the ELRs of HPV 2a (377 nucleotides) and HPV 57 (478 nucleotides), as well as DNA sequence comparisons, these two viruses could be grouped with the so-called mucosal HPVs. In a search for possible tissue-specific elements, a common amino acid motif, thr-thr/asp-pro-ala-ile/valile/leu was found in the L2 of all mucosal HPVs, as well as in HPV 2a and 57. The L2 of the cutaneous types contain the motif val-ser/thr-arg-thr-gln-tyr.     

Two novel genital human papillomavirus (HPV) types, HPV68 and HPV70, related to the potentially oncogenic HPV39.

The genomes of two novel human papillomavirus (HPV) types, HPV68 and HPV70, were cloned from a low-grade cervical intraepithelial neoplasia and a vulvar papilloma, respectively, and partially sequenced. Both types are related to HPV39, a potentially oncogenic virus. HPV68 and HPV70 were also detected in genital intraepithelial neoplasia from three patients and one patient, respectively. Comparison with sequence data in the literature indicates that the subgenomic ME180-HPV DNA fragment, cloned from a carcinoma cell line, corresponds to an HPV68 subtype and that several HPV DNA fragments amplified by PCR from genital neoplasia represent worldwide distributed variants of HPV68 and HPV70.     

Evaluation of a novel multiplex human papillomavirus (HPV) genotyping assay for HPV types in skin warts

Human papillomaviruses (HPV) of the genera alpha, mu, and nu induce benign tumors of the cutaneous epithelia that constitute a significant burden for immunocompromised adults. Currently, no gold standard for genotyping of these HPV types exists. In this study, we describe the prevalence of genus alpha, mu, and nu HPV types in cutaneous warts. We developed a novel multiplex HPV genotyping assay, BSwart-PCR/MPG (BSwart), to type sensitively and specifically 19 cutaneous HPV types frequently found in warts. BSwart-PCR/MPG is based on a multiplex PCR using broad-spectrum primers and subsequent multiplex hybridization to type-specific probes coupled to Luminex beads. In a first application comprising 100 cutaneous warts, the assay was compared to another, recently described genotyping assay, the HSL-PCR/MPG. When a 10-fold dilution series was used, the detection limit was between 10 and 100 HPV genomes per PCR. When comparing the two assays, there was an excellent agreement in detecting dominant HPV types; however, we also obtained evidence for a higher sensitivity of the BSwart assay for multiple infections in these cutaneous warts. Using BSwart, HPV was found in 95% of wart preparations, with HPV1 being most prevalent, followed by types 27, 57, and 2. Both novel BSwart and HSL-PCR/MPG HPV genotyping assays are powerful high-throughput tools that could be used to learn more about the natural history of cutaneous HPV. They would be advantageous to monitor the efficacy of future skin HPV vaccines and to identify novel HPV vaccine candidates.     

Serum antibodies to human papillomavirus (HPV) pseudovirions correlate with natural infection for 13 genital HPV types

BackgroundSerology for human papillomaviruses (HPV) types -16 and -18 is established as an important tool for studies of HPV vaccinology and epidemiology. However, as there are a large number of oncogenic genital types of HPV there is a need for development of high-throughput, validated HPV serological assays that can be used for more comprehensive seroepidemiological studies and for research on multivalent HPV vaccines.ObjectivesTo develop a multiplexed pseudovirion-based serological assay (PsV-Luminex) encompassing 21 HPV types and validate the method by correlating the serology with the presence of type specific HPV DNA in cervical samples.Study designCervical swabs from 3,291 unvaccinated women attending organized cervical screening in Slovenia were tested with 3 different HPV DNA detection methods and presence of HPV DNA compared to presence of serum antibodies to pseudovirions from 15 genital HPV types (HPV-6,-11,-16,-18,-31,-33,-35,-39,-45,-52,-56,-58,-59,-68,-73).ResultsOn average 51% of the HPV DNA positive women were seropositive for the same HPV type that was detected in the cervical specimen. We found a strong correlation with presence of HPV DNA and antibodies to the same HPV type for 13/15 genital HPV types (median OR = 5.7, CI 95% = 2.4–12.9). HPV-52 serology failed the validation and HPV-11 serology could not be validated because only a single woman was positive for HPV-11 DNA. The correlation between serology and HPV DNA status tended to be stronger among women infected with single HPV type (median OR = 10.5, CI 95% = 2.4–48.4) than among women with multiple HPV infections (median OR = 4.6, CI 95% = 1.8–11.7).ConclusionsA multiplexed HPV PsV-Luminex assay has been developed and validated to correlate with natural HPV infection for 13 HPV types, thus enabling more comprehensive studies in HPV epidemiology and vaccine research.     

Filaggrin expression in cutaneous and mucosal human papillomavirus induced lesions

A series of 32 human papillomavirus induced lesions derived from epidermis and mucosa was studied for the modulation of filaggrin-profilaggrin (F-PF) expression according to the degree of virus infection as compared to normal skin and mucosa biopsies. This investigation was carried out on frozen sections using indirect immunofluorescence for filaggrin detection and group specific viral antigen and by in situ hybridization with biotinylated probes for viral DNA detection and typing. The 9 cutaneous warts showed an increase of F-PF expression in upper layer cells as compared to normal epidermis, which could be related to the high production of virus (viral antigen and HPV types 1 or 2). The 5 condyloma acuminata displayed also an enhanced expression of these components which was located in several upper layers but virus infection was confirmed in 2 of them with HPV types 6, 11 or 16. The 6 laryngeal papillomas exhibited a granular reactivity pattern for F-PF in suprabasal cell layers with an increase in the upper layers; viral antigen was found in 4 cases and HPV DNA types 6, 11 or 16 were detected in 4 specimens. Conversely among 12 cervical intraepithelial neoplasia, F-PF was expressed only in very superficial layers in few cases, without any correlation with the DNA detection (6, 11 or 16, 18). Taken together these data are suggestive of an intense expression of F-PF in benign lesions which can replicate the virus and a discrete or an absent expression of these components in premalignant or malignant lesions.     

Human papillomavirus (HPV) genotyping using paired exfoliated cervicovaginal cells and paraffin-embedded tissues to highlight difficulties in attributing HPV types to specific lesions

Defining type-specific human papillomavirus (HPV) infections within cervical tissues is important for understanding the pathogenesis of cervical neoplasia and assessing the effectiveness of prophylactic vaccines with limited type-specific spectra. We compared HPV DNA-testing results from 146 matched exfoliated-cell and formalin-fixed-tissue specimens collected by cervicovaginal lavage (CVL) within 90 days of each other from women with histologically confirmed cervical intraepithelial lesions (CIN). The CVL specimens were HPV typed using a MY09/11 L1 consensus primer PCR method followed by dot blot hybridization. The tissue specimens were HPV typed using an SPF(10) line probe assay HPV detection system. Of the 146 specimen pairs with evidence of CIN in the tissue, 91.8% were positive for one or more HPV types in both the tissue and cellular specimens. Tissue sections were more likely to be HPV negative (P < 0.01). Typing directly from tissue sections resolved multiple infections detected in exfoliated cells to a single HPV type in only 46.9% of cases. Combined use of both specimen types to attribute lesions to HPV type 16 (HPV-16) and/or -18 led to 43.1% attributed to HPV-16 and/or -18 by both specimen types and 19.9% attributed to HPV-16 and/or -18 by one, but not both, specimen types. Unambiguous attribution of cervical lesions to a single, specific HPV type remains a difficult proposition. Use of multiple specimen types or the development of highly sensitive and robust in situ hybridization HPV-testing methods to evaluate the certainty of attribution of lesions to HPV types might provide insights in future efforts, including HPV vaccine trials.     

Characterization of gut-derived intraepithelial lymphocyte (IEL) residing in human papillomavirus (HPV)-infected intraepithelial neoplastic lesions

Citation Kojima S, Kawana K, Fujii T, Yokoyama T, Miura S, Tomio K, Tomio A, Yamashita A, Adachi K, Sato H, Nagamatsu T, Schust DJ, Kozuma S, Taketani Y. Characterization of gut‐derived intraepithelial lymphocyte (IEL) residing in human papillomavirus (HPV)‐infected intraepithelial neoplastic lesions.Am J Reprod Immunol 2011; 66: 435–443 Problem Mucosal T cells are the most likely direct effectors in host anti‐human papillomavirus adaptive immunity and regression of cervical intraepithelial neoplasia (CIN) lesions. There are no studies addressing intraepithelial lymphocytes (IELs) in CIN lesions. Method of study Cervical lymphocytes were collected using cytobrushes from patients with CIN and analyzed by FACS analysis. Comparisons were made between populations of cervical T cells in CIN regressors and non‐regressors. Results A median of 74% of cervical lymphocytes were CD3⁺ T cells. Populations of integrin αEβ7⁺ IEL in CIN lesions varied markedly among patients (6–57%). Approximately half of integrin β7⁺ T cells were CD45RA‐negative memory T cells. The number of integrin αEβ7⁺ cells among cervical T cells was significantly higher in CIN regressors when compared to non‐regressors. Conclusion Higher cervical IEL numbers are associated with spontaneous regression of CIN. Accumulation of cervical integrin αEβ7⁺ IEL may be necessary for local adaptive effector functions.     

Genomic diversity of human papillomavirus (HPV) Genotype 38

Human papillomavirus (HPV) genotype HPV 38 is a HPV genotype associated with skin cancer and is classified taxonomically in the beta‐PV genus–species 2. At least six genomic variants of HPV 38, including prototype isolate and its subtype FA125, have been characterized so far. In order to investigate further the genomic diversity of HPV 38, a total of 39 HPV 38 positive samples obtained from hairs plucked from pubic, scrotal, perianal or eyebrow regions from 31 immunocompetent healthy male individuals were analyzed. The characterization of genomic variants was based on analysis of L1, E6, and E7 genomic regions. Sequence analysis revealed the presence of a single genomic variant in 35 samples and the presence of at least two different HPV 38 genomic sequences in four samples. A total of nine, nine, and five L1, E6, and E7 genomic variants were identified among 35 isolates, respectively. After combining nucleotide variations in all three genomic regions for a particular isolate, 13 different variants were identified, of which 6 and 7 corresponded to HPV 38 and FA125, respectively. In addition to 5 genomic variants identified previously (prototype isolate, subtype FA125, putative subtype AF091444, isolates U21875 and AF091443), 12 novel genomic variants were characterized. A sixth genomic variant described previously (L38917) was found to be identical with prototype HPV 38 isolate. Taking into account the results of this and previous studies, at least seventeen HPV 38 genomic variants exist today, 12 of which are described for the first time in this study. J. Med. Virol. 81:288–295, 2009. © 2008 Wiley‐Liss, Inc.     

Modulation of apoptosis by human papillomavirus (HPV) oncoproteins

Summary. The regulation of host-mediated apoptosis by the E6 and E7 oncoproteins has garnered attention because it is believed to be an important strategy employed by high-risk (HR)-human papillomaviruses (HPVs) to evade immune surveillance. Additionally, the revelation that E5 can protect cells from tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis suggests that it may also play a role in undermining host defense mechanisms. Cellular transformation is an unintended consequence of persistent infection by HR-HPVs, and it is therefore likely that the primary function of E5, E6 and E7 is to regulate cell survival throughout the normal viral life cycle in order to ensure viral replication and promote the spread of progeny. The purpose of this article is to review the literature on the regulation of host-mediated apoptosis by E5, E6 and E7 that describes the mechanisms employed by HR-HPVs to persist in the host and create the conditions necessary for cellular transformation.     

Human papillomavirus (HPV) types 101 and 103 isolated from cervicovaginal cells lack an E6 open reading frame (ORF) and are related to gamma-papillomaviruses

Complete genomes of HPV101 and HPV103 were PCR amplified and cloned from cervicovaginal cells of a 34-year-old female with cervical intraepithelial neoplasia grade 3 (CIN 3) and a 30-year-old female with a normal Pap test, respectively. HPV101 and HPV103 contain 4 early genes (E7, E1, E2, and E4) and 2 late genes (L2 and L1), but both lack the canonical E6 ORF. Pairwise alignment similarity of the L1 ORF nucleotide sequences of HPV101 and HPV103 indicated that they are at least 30% dissimilar to each other and all known PVs. However, similarities of the other ORFs (E7, E1, E2, and L2) indicated that HPV101 and HPV103 are most related to each other. Phylogenetic analyses revealed that these two types form a monophyletic clade, clustering together with the gamma- and pi-PV groups. These data demonstrated that HPV genomes closely related to papillomaviruses identified from cutaneous epithelia can be isolated from the genital mucosal region. Moreover, this is the first report of HPVs lacking an E6 ORF and phylogenetic evidence suggests this occurred subsequent to their emergence from the gamma-/pi-PVs.     

Detection of human papillomavirus (HPV) type 47 DNA in malignant lesions from epidermodysplasia verruciformis by protocols for precise typing of related HPV DNAs.

Our discovery of human papillomavirus type 47 (HPV47) in benign lesions from a patient suffering from epidermodysplasia verruciformis prompted us to examine whether the viral DNA also resided in malignant lesions from the same patient. By using newly devised protocols for amplifying a group of epidermodysplasia verruciformis-associated HPV DNAs by PCR and differentially identifying them by reverse-phase dot blot hybridization, we demonstrated that HPV47 DNA, but not other HPV DNAs of the group, was abundant (about 10(3) copies per diploid amount of cell DNA) in DNAs prepared from three carcinomas. Using DNA from one of these carcinomas, we also confirmed that DNA of HPV5, HPV14, or HPV21, detected in significant amounts in DNAs from benign lesions from the patient, were present only in negligible amounts or not at all. The results suggest the involvement of HPV47 DNA in tumorigenesis. Furthermore, we demonstrated by the Southern technique that most, if not all, of the HPV47 DNA consists of either a unit (or a nongrossly deleted unit) length of the viral genome carrying no (or no gross) internal rearrangements or tandem repeats. This and other results obtained by this technique indicated that a considerable amount of the viral DNA resides as a circular monomer a unit length of the viral genome in carcinoma cells, while the remainder reside as catenanes, concatemers, or both. The concatemers were considered more likely to be replicated without integration into cellular DNA than to be integrated, because no bands for the corresponding fragments including integration sites were detected by treatment with restriction enzymes that would have produced such fragments.     

Deceiving high-grade cervical dysplasias identified as human papillomavirus non-16 and non-18 types by Invader human papillomavirus assays

High-grade cervical intraepithelial lesions (HGCINs) are easily diagnosed by established histologic criteria. However, we encountered problematic cases that are difficult to diagnose because features intermediate between dysplasia and metaplasia are present. p16 and Ki-67 immunostains proved HGCIN in these difficult and unusual cases. Because these are unusual cases of cervical dysplasia, we decided to type the human papillomavirus (HPV) using the Invader HPV test with analyte-specific reagents developed by Third Wave Technologies (Madison, WI, USA) (a new HPV screening assay applicable to tissue and amenable to rapid, sensitive, and specific detection of 14 high- to intermediate-risk HPV types) and a panel of immunostains. Results of these difficult cases are compared with classic HGCIN cases. We searched our pathology files over a period of 16 months for high-grade squamous intraepithelial lesion, cervical intraepithelial neoplasia II, cervical intraepithelial neoplasia III, and p16. To identify cases of difficult HGCIN with features intermediate between dysplasia and metaplasia, we reviewed all surgical cases of HGCIN that required p16 and Ki-67 diagnosis confirmation. Cases of interest were also stained with ProExC. Human papillomavirus screening and HPV 16/18 typing were performed by the Invader assays as described previously. Ten cases of classic HGCIN were easily diagnosed by hypercellularity, significant atypia, mitotic figures, and diffuse staining by p16, Ki67 and ProExC. The Invader assay identified HPV 16 (A9 positive/HPV16 positive) in 7 of 10 cases; the 3 others were A7 positive/not HPV18 (1) and A9 positive/not HPV16 (2). Eight cases of difficult HGCIN were identified. These showed only mild-to-moderate cellularity, a lack of significant atypia, absent-to-rare mitotic figures, and diffuse staining by p16, Ki-67, and ProExC. Human papillomavirus DNA was detected in 5 of 8 cases: only 1 was A9 positive/HPV16 positive, 1 was A5/A6 positive, 1 was A7 positive/not HPV18, and 2 were A9 positive/not HPV16. Three remaining cases demonstrated sufficient DNA to be analyzed by the Invader assay, but results were negative. This is a poorly recognized unusual group of cervical HGCIN with features intermediate between dysplasia and metaplasia that is easily confused by histologic examination. Immunostains prove the high-grade nature of these lesions, and Invader assay demonstrates association with HPV types other than 16/18 (ie, other HPV types detected by Invader assay). In this study, we present an unusual group of cases of high-grade dysplasia, not recognized by hematoxylin and eosin but identified by Ki67 and P16. It is very important to emphasize that this unusual group of high-grade dysplasias is associated with high-risk HPV but with types other than 16/18.     

Cervical human papillomavirus (HPV) infection and HPV type 16 antibodies in South African women

There is a high incidence of cervical cancer in South African women. No large studies to assess human papillomavirus virus (HPV) infection or HPV type 16 (HPV-16) exposure have occurred in the region, a requirement for policy making with regards to HPV screening and the introduction of vaccines. Control women (n = 1,003) enrolled in a case control study of hormonal contraceptives and cervical cancer were tested for 27 cervical HPV types by reverse line blot analysis. The seroprevalence of HPV-16 immunoglobulin G (IgG) and IgA antibodies was assessed by a virus-like particle-based enzyme-linked immunoassay of 908 and 904 control women, respectively, and of 474 women with cervical cancer. The cervical HPV prevalence was 26.1%. The HPV-16 IgG seroprevalence was 44.4% and the HPV-16 IgA seroprevalence was 28.7% in control women, and these levels were significantly higher (61.8% and 52.7%, respectively) for women with cervical cancer (odds ratio [OR], 2.1 and 2.8, respectively). The cervical HPV prevalence showed an association with cervical disease, and the HPV-16 IgG prevalence decreased while the HPV-16 IgA prevalence increased with increasing age (P < 0.05). The prevalence of oncogenic HPV types (including HPV-16) decreased with age, whereas nononcogenic HPV types showed limited association with age. Multivariate analysis revealed cervical HPV infection to be associated with herpes simplex virus type 2 infection (OR, 1.7) and increasing years of education (OR, 1.9). HPV-16 IgG antibodies were inversely associated with current smoking status (OR, 0.6), and the presence of HPV-16 IgA antibodies was inversely associated with the use of alcohol (OR, 2.1) and inversely associated with the use of oral contraceptives (OR, 0.6). High levels of exposure to HPV, and particularly HPV-16, were evident in this population. The apparent increase of serum HPV-16 IgA with increasing age requires further investigation.     

Novel microsphere-based method for detection and typing of 46 mucosal human papillomavirus types

We have developed a novel microsphere-based genotyping method for 46 mucosal human papillomavirus (HPV) types. HPV DNA was amplified by PCR using general primers and typed by hybridization to HPV type-specific probes coupled to sortable microspheres based on the Luminex xMAP technology. Hybridization to each probe was specific for each HPV type without cross-hybridization and sensitive enough to allow typing of HPV contained in clinical specimens. The method was validated with direct sequencing and the Roche Linear Array genotyping method.     

Distribution and viral load of eight oncogenic types of human papillomavirus (HPV) and HPV 16 integration status in cervical intraepithelial neoplasia and carcinoma.

Current human papillomavirus (HPV) DNA testing using pooled probes, although sensitive, lacks specificity in predicting the risk of high-grade cervical intraepithelial neoplasia (CIN 2/3) progression. To evaluate selected HPV genotyping, viral load, and viral integration status as potential predictive markers for CIN progression, we performed HPV genotyping in formalin-fixed, paraffin-embedded cervical tissue with cervical carcinoma (29 cases) and CINs (CIN 1, 27 cases; CIN 2, 28 cases; CIN 3, 33 cases). General HPVs were screened using consensus primers GP5+/GP6+ and PGMY09/11. HPV genotyping and viral load measurement were performed using quantitative real-time PCR for eight oncogenic HPV types (16, 18, 31, 33, 35, 45, 52, and 58). HPV 16 viral integration status was evaluated by measuring HPV 16 E2/E6 ratio. We observed that HPV DNA positivity increased in parallel with the severity of CINs and carcinoma, with 59% positivity in CIN 1, 68% in CIN 2, 76% in CIN 3, and 97% in carcinoma (P trend=0.004). The eight oncogenic HPV types were significantly associated with CIN 2/3 (81%) and carcinoma (93%) (odds ratio (OR), 15.0; 95% confidence interval (CI), 5.67-39.76; P<0.0001) compared with the unknown HPV types (OR, 2.87; 95% CI, 0.89-9.22; P=0.08). HPV 16 was the predominant oncogenic HPV type in CIN 2/3 (51%) and carcinoma (71%) and integrated significantly more frequently in carcinoma than in CIN 2/3 (P=0.004). No significant differences in viral load were observed across the disease categories. Our findings suggest that selected genotyping for the eight oncogenic HPV types might be useful in separating women with a higher risk of CIN progression from those with a minimal risk. We also conclude that the HPV 16 integration status has potential to be a marker for risk assessment of CIN progression.     

Biologic characteristics of specific human papillomavirus types predicted from morphology of cervical lesions.

Human papillomavirus (HPV) DNA was detected by Southern blot hybridization in cervicovaginal lavage samples from 199 of 329 (60.5%) women attending a municipal hospital colposcopy clinic. Human papillomavirus was identified in 195 of 264 (73.9%) patients with a squamous intraepithelial lesion or cancer on biopsy or Papanicolaou smear (Bethesda system) compared with 11 of 65 (16.9%) without squamous intraepithelial lesion (P < .0001). The most common HPV type identified was HPV 16 (20.6% of positive samples), and 36.7% of isolates contained uncharacterized HPVs. Of women with cervical intraepithelial neoplasia (CIN) grade III or cancer, 23.4% were infected with HPV 16 compared with less than 4% with any other single HPV type. Based on biopsy diagnosis in patients infected with specific HPV types, HPVs 6 and 11 had low oncogenic potential; HPVs 18, 31, 35, and 45 had intermediate oncogenic potential; and HPVs 16 and 33 had high oncogenic potential. Hyperchromatic, unusually enlarged nuclei ("meganuclei"), and/or abnormal mitoses were found significantly more often in lesions infected with HPVs 16, 33, and 35 than in those infected with HPVs 6, 11, 18, 31, and 45, even in low-grade lesions, and may represent a histologic marker for HPVs with significant oncogenic potential. Human papillomavirus capsid protein was detected significantly less often by immunocytochemical staining in CIN I and CIN II lesions infected with HPVs 16 and 33 (8.3%) than in those infected with HPVs 6, 11, 18, and 31 (60%; P = .007), suggesting early abnormalities in cellular differentiation in lesions infected with highly oncogenic HPVs.     

Prevalence of human papillomavirus types in cervical lesions from women in rural Western India

Cervical cancer is the most common cancer among women in many areas of India which contributes for a fifth of the global burden of disease. Persistent infection with one of the high-risk human papillomaviruses (HPV) has been established as the cause for cervical cancer and the documentation of the prevalence of HPV types in cervical cancer in different regions of India is useful for a prevention program combining both screening and vaccination. In this study, the HPV type distribution and the frequency of p16(INK4a) immunoexpression have been determined in 125 cases of inflammatory lesions or grade 1 cervical intraepithelial neoplasia, 74 cases of grade 2, 72 cases of grade 3, and 113 cervical cancer cases diagnosed among women from rural Solapur and Osmanabad districts, Maharashtra. The overall prevalence of high-risk HPV was 37.6% in inflammatory lesions or grade 1 cervical intraepithelial neoplasia, 63.5% in grade 2, 97.2% in grade 3 and 92% in cervical cancer cases. HPV 16 and HPV 18 were detected in 80.6% of grade 3 cervical intraepithelial neoplasia and 86.5% of cervical cancer cases. 94.7% of the cervical cancer and 84.4% of the high grade lesions with a strong and full thickness staining for p16(INK4a) were positive for HPV infection; p16(INK4a) immunoexpression increased with worsening grade of cervical intraepithelial neoplasia. The HPV genotyping data showing a high HPV 16 and 18 prevalence in cancer specimens indicate that prophylactic HPV 16/18 vaccination would have a significant impact on the prevention of cervical cancer in India.     

Candidate human papillomavirus (HPV) type 27b: nucleotide sequence and heterogeneity with HPV 27

More than 100 human papillomavirus (HPV) types have been reported as tumorigenic agents. HPV types 2 and 27 were identified in benign tumors and classified closely according to the sequence homology. An HPV type 2 related sequence was identified previously in an oral papilloma. However, the correct typing and sequencing was impossible at that time. A candidate HPV was cloned by the long-PCR technique from an oral papilloma and characterized by nucleotide sequence. This virus was basically HPV type 27, but there was some heterogeneity in comparison with the prototype. Most differences were nucleotide-sequence variations. Two of four-nucleotide insertions were frame shift, resulting in longer L1 protein than that of HPV 27.     

Prevaccination genomic diversity of human papillomavirus genotype 6 (HPV 6)

Prevaccination genomic diversity of human papillomavirus genotype 6 (HPV 6) was established by sequencing 3798 bp of 77 clinically important HPV 6 isolates obtained from 45 and 32 patients with genital warts and laryngeal papillomas, respectively. By analyzing pooled L1, LCR, E6, E2, and E5 nucleotide data of an individual isolate, a total of 36 different genomic variants were identified, of which six (12 isolates), one (one isolate) and 29 (64 isolates) corresponded to HPV 6b, HPV 6a, and HPV 6vc genetic lineages, respectively. Several novel, potentially important mutations were identified. Non-prototypic HPV 6vc genomic variants were found in the majority of genital warts and laryngeal papillomas included in the study. The presence of serious HPV 6 genome sequence errors was confirmed and novel sequence errors were identified in sequence repositories.