Human papillomavirus type-16 variants in Quechua aboriginals from Argentina

Cervical carcinoma is the leading cause of cancer death in Quechua indians from Jujuy (northwestern Argentina). To determine the prevalence of HPV-16 variants, 106 HPV-16 positive cervical samples were studied, including 33 low-grade squamous intraepithelial lesions (LSIL), 28 high-grade squamous intraepithelial lesions (HSIL), 9 invasive cervical cancer (ICC), and 36 samples from women with normal colposcopy and cytology. HPV genome variability was examined in the L1 and E6 genes by PCR-hybridization. In a subset of 20 samples, a LCR fragment was also analyzed by PCR-sequencing. Most variants belonged to the European branch with subtle differences that depended on the viral gene fragment studied. Only about 10% of the specimens had non-European variants, including eight Asian-American, two Asian, and one North-American-1. E6 gene analysis revealed that 43% of the samples were identical to HPV-16 prototype, while 57% corresponded to variants. Interestingly, the majority (87%) of normal smears had HPV-16 prototype, whereas variants were detected mainly in SIL and ICC. LCR sequencing yielded 80% of variants, including 69% of European, 19% Asian-American, and 12% Asian. We identified a new variant, the Argentine Quechua-51 (AQ-51), similar to B-14 plus two additional changes: G7842-->A and A7837-->C; phylogenetic inference allocated it in the Asian-American branch. The high proportion of European variants may reflect Spanish colonial influence on these native Inca descendants. The predominance of HPV-16 variants in pathologic samples when compared to normal controls could have implications for the natural history of cervical lesions.     

Immunoperoxidase localization of papillomavirus antigen in cutaneous warts and bowenoid papulosis

Using the immunoperoxidase technique and a broadly cross-reactive antiserum which detects infection with any papillomavirus, papillomavirus capsid antigen was demonstrated in 25 of 48 cutaneous papillomas and in two of 38 cutaneous dysplasias. Both positive dysplastic lesions were diagnosed on histopathologic examination as bowenoid papulosis. Antigen-positive cutaneous warts were scattered in all age categories and at all body sites. In addition, there was little variation in antigen expression by morphologic type of wart. Antigen was localized in the nucleus of superficial epithelial cells. The amount of staining was variable, with some warts showing large numbers of stained nuclei. In other warts only isolated cells stained. In both cases of bowenoid papulosis, small foci of positively stained cells were observed. The finding of papillomavirus antigen in two of 21 cases of bowenoid papulosis is suggestive of an etiologic relationship between this lesion and a papillomavirus. An examination of antigen-negative cases of bowenoid papulosis for a papillomavirus genome will be necessary to confirm these results.     

Identification of recombinant human papillomavirus type 16 variants

Intratypic diversity of human papillomavirus (HPV) genome is generally characterized by point mutation, insertion, and/or deletion. Using PCR-based cloning and sequencing, we detected concurrent infection with 8 HPV16 variants in a woman enrolled in the ASCUS-LSIL Triage Study. The European variant was the major variant; each of the 7 minor variants had partial DNA sequences identical to the European variant and another part identical to the African 2 variant. At a follow-up visit, only an HPV16 African 2 variant was detected. Results from the present study suggest presence of intratypic recombination of HPV genome in natural infection.     

Human papillomavirus 16 variants from Zambian women with normal pap smears

Human papillomavirus (HPV) type 16 is the most prevalent high-risk viral genotype associated with cervical cancer. Six distinct phylogenetic clusters of HPVs have been identified and are distributed differently across five continents. HPV16 DNA was extracted from cervicolavage samples from women with normal pap smears. The LCR regions were amplified in triplicate, cloned, sequenced, and analyzed from a total of 11 recovered HPV16 positive samples [Ng'andwe et al. (2007): BMC Infect Dis 7:77] were analyzed for sequence variation. The HPV16 LCR variants were assessed for promoter activity by use of a luciferase reporter gene. Six novel HPV16 variants with nucleotide exchanges in the LCR region were identified. Five clones were classified as European group HPV16 variants and one as an African group variant. Two of these variants had relatively lower promoter activity, 30% of that of the wild-type strain. The decreased promoter activity of some HPV16 variants may decrease expression of viral oncogenes and may be linked with the development, phenotype and severity of the cervical lesions in women infected with these across HPV16 variants.     

Immunohistochemistry (S 100, KL 1) and human papillomavirus DNA hybridization on Morbus Bowen and bowenoid papulosis

Summary In this study 55 paraffin embedded samples defined as Bowen's disease or bowenoid papulosis were investigated with antibodies against S 100 protein and keratins (KL 1). S 100-positive cells were quantified and related to defined section area of the epidermal compartment by computer-assisted image analysis. The density of S 100-positive cells was compared with normal skin and was particularly related to growth patterns and keratinization of the different lesions under study. S 100-positive dendritic cells were found to be reduced overall in bowenoid lesions when compared with normal skin. Lesions with high counts of S 100-positive dendritic cells most frequentty showed a solitary growth pattern with highly conserved architecture and differentiation and no tendency to stromal invasion. In contrast, cases with low counts of S 100-positive cells very often showed multifocal development, a high degree of architectural disturbance and dedifferentiation. In this group, stromal invasion (cases of invasive carcinoma associated with Bowen's disease) was seen more often. Interestingly, this latter group of cases also revealed a peculiar keratin pattern. Frequently, the basal cell layer was decorated with KL 1 antibody, which usually recognizes only suprabasaly located keratinocytes. No differences between Bowen's disease and bowenoid papulosis were found in terms of densities of S 100-positive dendritic cells and keratin pattern. In our experience, extragenital Bowen's disease and genital Bowen's disease can not be distinguished on purely morphological grounds or with the immunocytochemical approach presented here. Interestingly, when employing in situ hybridization with HPV 16 probes three of seven samples of genital Bowen's disease harboured HPV 16 DNA, whereas six cases of extragenital disease were negative.Supported by the Deutsche Forschungsgemeinschaft (Lo 285/2-4)     

Oncogenic potential diverge among human papillomavirus type 16 natural variants

We compared E6/E7 protein properties of three different HPV-16 variants: AA, E-P and E-350G. Primary human foreskin keratinocytes (PHFK) were transduced with HPV-16 E6 and E7 and evaluated for proliferation and ability to grow in soft agar. E-P infected keratinocytes presented the lowest efficiency in colony formation. AA and E-350G keratinocytes attained higher capacity for in vitro transformation. We observed similar degradation of TP53 among HPV-16 variants. Furthermore, we accessed the expression profile in early (p5) and late passage (p30) transduced cells of 84 genes commonly involved in carcinogenesis. Most differences could be attributed to HPV-16 E6/E7 expression. In particular, we detected different expression of ITGA2 and CHEK2 in keratinocytes infected with AA and AA/E-350G late passage cells, respectively, and higher expression of MAP2K1 in E-350G transduced keratinocytes. Our results indicate differences among HPV-16 variants that could explain, at least in part, differences in oncogenic potential attributed to these variants.     

宫颈癌组织中人乳头瘤病毒16型L1基因的克隆及序列分析

目的人乳头瘤病毒１６型（ＨＰＶ１６）晚期基因区（Ｌ１）编码病毒的主要衣壳蛋白,且ＨＰＶ１６感染与宫颈癌发生、发展关系密切,故对中国妇女感染的ＨＰＶ１６基因进行克隆及序列分析有重要实际意义。方法采用聚合酶链反应技术（ＰＣＲ）扩增了３例中国妇女宫颈癌组织中ＨＰＶ１６的Ｌ１基因片段,并对其进行了克隆及全序列分析。结果发现３个ＨＰＶ１６Ｌ１基因核苷酸序列有４处均与最初报道的ＨＰＶ１６Ｌ１ＤＮＡ序列不同,并由此引起所编码的氨基酸亦发生变化。结论中国妇女宫颈癌组织中ＨＰＶ１６Ｌ１核苷酸有一定程度变异。     

Human papillomavirus type 16 E5 protein as a therapeutic target

Cervical cancer is a progressive disease with an onset of one to two decades on average. During the productive replication stage, the Human papillomavirus (HPV) genome is maintained episomally in the infected cervical epithelium and early gene products, including E5, are expressed. Therefore, E5 has a potential to contribute to the HPV-associated carcinogenic process. In invasive malignancies, the HPV genomes are commonly integrated into the host genome, and E6 and E7 genes remain intact. However, the E5 is lost or, if present, under-expressed as compared with the E6 and E7 proteins. This suggests that E5 may play a critical role in the genesis of cervical cancer but less of a role in its persistence or progression. In the initiation of neoplasia and the premalignant stage, there are fewer malignant cells than in the invasive malignancies. Moreover, cells in the invasive malignant stage are found to have a very low level of MHC class I and II, which could hamper the presentation of the antigen and lead to a decreased immune response. Since the E5 protein is likely to play a role during the early tumorigenesis stage, a therapeutic vaccine to target and eliminate the E5-expressing cells may be a good strategy to prevent premalignant lesions from progressing toward invasive cervical cancers. This paper provides an overview of HPV-induced cervical carcinogenesis and strategies for designing prophylactic and therapeutic vaccines to prevent and cure the cervical cancer. In particular, focus will be on the rationale of targeting the E5 protein to develop therapeutic vaccines.     

Human papillomavirus type 11DNA in papillary squamous cell lung carcinoma

Summary We report a case of papillary squamous cell carcinoma of the lung developing in relation to a condylomatous papilloma and related to human papillomavirus (HPV) infection. The viral origin of the bronchial papillomatous lesion is strongly suggested by cytological and histological features with marked condylomatous changes. No viral capsid antigen was detected by immunohistochemistry. Transmission electron microscopy failed to reveal intranuclear viral-like particles in the papillary part of the carcinoma, but typical ultrastructural koilocytotic cells with irregular nucleus and coarse chromatin were observed. HPV DNA type 11 was detected by in situ hybridization using biotinylated probes on paraffin-embedded specimens, under stringent conditions (T _m }-12, 50% formamide). Papillary squamous cell carcinoma may result from the malignant conversion of benign squamous papilloma of the bronchus. HPV type 11 may be associated with malignant conversion of benign papilloma of the pulmonary tract, as in the upper respiratory tract. In situ hybridization with biotinylated probes is a relatively simple and appropriate method for retrospective analysis of HPV DNA sequences in surgical specimens.     

Human papillomavirus type 16 variants in cervical cancer from an admixtured population in Brazil

Several studies indicate that molecular variants of HPV-16 have different geographic distribution and risk associated with persistent infection and development of high-grade cervical lesions. In the present study, the frequency of HPV-16 variants was determined in 81 biopsies from women with cervical intraepithelial neoplasia grade III or invasive cervical cancer from the city of Belem, Northern Brazil. Host DNAs were also genotyped in order to analyze the ethnicity-related distribution of these variants. Nine different HPV-16 LCR variants belonging to four phylogenetic branches were identified. Among these, two new isolates were characterized. The most prevalent HPV-16 variant detected was the Asian-American B-2, followed by the European B-12 and the European prototype. Infections by multiple variants were observed in both invasive cervical cancer and cervical intraepithelial neoplasia grade III cases. The analysis of a specific polymorphism within the E6 viral gene was performed in a subset of 76 isolates. The E6-350G polymorphism was significantly more frequent in Asian-American variants. The HPV-16 variability detected followed the same pattern of the genetic ancestry observed in Northern Brazil, with European, Amerindian and African roots. Although African ancestry was higher among women infected by the prototype, no correlation between ethnical origin and HPV-16 variants was found. These results corroborate previous data showing a high frequency of Asian-American variants in cervical neoplasia among women with multiethnic origin.     

Association of human papillomavirus type 16 and its genetic variants with cervical lesion in Korea

Persistent human papillomavirus type 16 (HPV16) is the major risk factor for cervical cancer. HPV16 intratypic variants differ in their geographical distribution and oncogenic potential. This study aimed to analyze the distribution of HPV16 variants and their association with cervical lesion histopathology in Korean women. In total, 133 HPV16‐positive cervical samples from women admitted to Seoul National University Boramae Hospital were analyzed by sequencing E6, E7, and L1 genes and the long control region (LCR), and the variant distribution according to cervical lesion grade was determined. Isolates were grouped into a phylogenetic lineage, and A1‐3, A4, C, and D sublineages were detected in 54.1, 37.8, 0.7, and 7.4% of samples, respectively. The most commonly observed LCR variations were 7521G>A (91.5%), 7730A>C (59.6%), and 7842G>A (59.6%). Furthermore, A4 or D sublineage‐positive women had a higher risk for cervical cancer than women who were positive for A1–3. Among HPV phylogenetic clusters, A1–3 was the predominant sublineage, and within A1–3, the 350G polymorphism was highly frequent. These results differed from those of previous studies in Korea and other Asian countries. The findings suggest that cervical neoplasia incidence in HPV16‐infected patients could be affected by the distribution of HPV16 variants in the population.     

人乳头瘤病毒E6、E7的表达对足叶乙甙作用下细胞凋亡的影响

目的探讨人乳头瘤毒(HPV)16早期基因E6和E7的表达对NIKS细胞凋亡表型的影响。方法用含有HPV16的E6、HPV16E7、HPV16E6E7病毒癌基因的逆转录病毒感染角质生成细胞株NIKS,puromycin筛选稳定表达细胞;基因组PCR和Western blot方法验证E6和E7的表达;转染后的NIKS细胞用不同浓度的足叶乙甙处理,流式细胞仪和Annexin V染色检测细胞凋亡情况。结果经逆转录病毒感染后,建立表达E6、E7及E6E7的NIKS细胞株,基因组PCR证明E6和E7整合入NIKS细胞基因组;Western blot证实表达的E6、E7具有生物学活性,能够分别降解p53和pRB;在足叶乙甙处理后,E6、E7以及E6E7表达细胞发生明显的细胞死亡,E6和E7具有叠加作用,且具有剂量依赖性,Annexin V染色证实细胞发生凋亡,凋亡率分别为(33.5±3.2)%、(38.3±2.4)%和(56.7±4.3)%。结论人乳头瘤病毒E6和E7的表达都可以促进细胞对DNA损伤药物的敏感性,提示乳头瘤病毒感染状态有可能影响肿瘤细胞对化疗的敏感性。     

Human papillomavirus 16 E6 variants differ in their dysregulation of human keratinocyte differentiation and apoptosis

L83V-related variants of human papillomavirus (HPV) 16 E6, exemplified by the Asian-American variant Q14H/H78Y/L83V, were shown to be more prevalent than E6 prototype in progressing lesions and cervical cancer. We evaluated functions relevant to carcinogenesis for the E6 variants L83V, R10/L83V and Q14H/H78Y/L83V as well as the prototype in a model of human normal immortalized keratinocytes (NIKS). All E6 expressing NIKS equally abrogated growth arrest and DNA damage responses. Organotypic cultures derived from these keratinocytes demonstrated hyperplasia and aberrantly expressed keratin 5 in the suprabasal compartment. In contrast, differentiation and induction of apoptosis varied. The E6 variant rafts expressed keratin 10 in nearly all suprabasal cells while the prototype raft showed keratin 10 staining in a subset of suprabasal cells only. In addition, E6 variant NIKS expressing R10G/L83V and Q14H/H78Y/L83V were more prone to undergo cell-detachment-induced apoptosis (anoikis) than NIKS expressing E6 prototype. The combined differentiation and apoptosis pattern of high-risk E6 variants, especially of Q14H/H78Y/L83V, may reflect a phenotype beneficial to carcinogenesis and viral life cycle.     

Variants of human papillomavirus type 16 predispose toward persistent infection

A cohort study of 292 Chinese women was conducted to determine the relationship between human papillomavirus (HPV) type 16 variants and persistent viral infection. Enrolled patients were HPV16 positive and had both normal cytology and histology. Flow-through hybridization and gene chip technology was used to identify the HPV type. A PCR sequencing assay was performed to find HPV16 E2, E6 and E7 gene variants. The associations between these variants and HPV16 persistent infection was analyzed by Fisher’s exact test. It was found that the variants T178G, T350G and A442C in the E6 gene, as well as C3158A and G3248A variants in the E2 gene were associated with persistent HPV16 infection. No link was observed between E7 variants and persistent viral infection. Our findings suggest that detection of specific HPV variants would help identify patients who are at high risk for viral persistence and development of cervical neoplasia.     

Detection and localization of human papillomavirus DNA in human genital condylomas by in situ hybridization with biotinylated probes

We have examined the distribution of human papillomavirus (HPV) DNA in paraffin sections of humans warts by in situ hybridization with biotin-labeled DNA probes. Recombinant plasmid DNAs (HPV-1, -6, -11, -16) were labeled by nick translation with biotinylated deoxyuridine triphosphate. Paraffin sections were hybridized with the probes for 18 h in stringent or non-stringent conditions, and DNA-DNA hybrids were detected by immunocytochemistry. Paraffin sections of warts were also examined for the presence of HPV capsid antigen with the avidin-biotin peroxidase complex method for immunocytochemistry. HPV DNA was detected and localized in paraffin sections from a plantar wart, a laryngeal papilloma, and seven anogenital condylomas. The specific HPV type present in each lesion was determined by hybridization under stringent conditions with the homologous DNA probe. The papillomas were found to contain many more cells with replicating virus DNA, as demonstrated by in situ hybridization, than was apparent from the number of cells containing detectable virus antigen. In situ hybridization with biotin-labeled probes is an effective technique for the identification of HPV infection in routinely collected and processed tissue specimens.     

White variants of Trichophyton violaceum isolated in Ethiopia

Certain dermatophytes are geographically restricted and endemic in particular parts of the world, while other species may have a sporadic but worldwide distribution. Trichophyton violaceum is one of the most common dermatophytes causing tinea capitis, and is the predominant cause of tinea in Africa, South America and the Indian subcontinent. Among 1187 dermatophyte isolates collected from Ethiopian patients with various types of tinea, 32 isolates had uncharacteristic phenotypic features. Based on conventional methods complemented by sequence analysis of the rDNA ITS2 region, these isolates were identified as white variants of T. violaceum. This is the first time that white isolates of T. violaceum have been identified in Ethiopia.     

肺癌组织中人乳头瘤病毒16和18型DNA相关序列的检测

采用聚合酶链反应技术（ＰＣＲ）及用ＰＣＲ法制备生物素标记探针的斑点杂交法,检测５０例肺癌、１８例肺良性病及４例胎肺组织中高危险型人乳头瘤病毒（ＨＰＶ）１６、１８型ＤＮＡ相关序列,以探讨ＨＰＶ与肺癌之间发生的关系。结果３２％的肺癌组织中检测出ＨＰＶ１６、１８ＤＮＡ,其中ＨＰＶ１６ＤＮＡ阳性１０例,ＨＰＶ１８ＤＮＡ阳性５例,１例同时含ＨＰＶ１６、１８ＤＮＡ。２７例鳞癌组织中ＨＰＶＤＮＡ阳性率为４８．２％。而肺良性病组织及胎肺组织均未发现ＨＰＶＤＮＡ。ＨＰＶＤＮＡ呈阳性的肺癌患者绝大多数为重度吸烟者。提示原发性肺癌的发生可能与ＨＰＶ感染有关。