Phylogenetically related, clinically different: human papillomaviruses 6 and 11 variants distribution in genital warts and in laryngeal papillomatosis

The role of HPV11 E7 in modulating STING-dependent interferon β response in recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP) is a rare benign tumor caused mainly by the infection of the respiratory tract epithelial cells by the human papillomavirus (HPV) type 6/11. However, the specific mechanisms underlying the inhibition of the host's innate immune response by HPV remain unclear. For this purpose, we employed single-cell RNA sequencing to analyze the states of various immune cells in RRP samples post-HPV infection and utilized a cellular model of HPV infection to elucidate the mechanisms by which HPV evades the innate immune system in RRP. The results revealed distinct immune cell heterogeneity in RRP and demonstrated that HPV11 E7 can inhibit the phosphorylation of the stimulator of interferon genes protein, thereby circumventing the body's antiviral response. In vitro co-culture experiments demonstrated that stimulation of macrophages to produce interferon-beta induced the death of HPV-infected epithelial cells, also reducing HPV viral levels. In summary, our study preliminarily identifies the potential mechanisms by which HPV evades the host's antiviral immune response, as well as the latent antiviral functions exhibited by activated macrophages. This research serves as an initial exploration of antiviral immune evasion in RRP, laying a solid foundation for investigating immunotherapeutic approaches for the disease.IMPORTANCESurgical tumor reduction is the most common treatment for recurrent respiratory papillomatosis (RRP). One of the characteristics of RRP is its persistent recurrence, and multiple surgeries are usually required to control the symptoms. Recently, some adjuvant therapies have shown effectiveness, but none of them can completely clear human papillomavirus (HPV) infection, and thus, a localized antiviral immune response is significant for disease control; after all, HPV infection is limited to the epithelium. Inhibition of interferon-beta (IFN-β) secretion by HPV11 E7 viral proteins in epithelial cells by affecting stimulator of interferon genes phosphorylation may account for the persistence of low-risk HPV replication in the RRP. Moreover, suppression of the IFN-I pathway in RRP cell types might provide clues regarding the hyporeactive function of local immune cells. However, activation of macrophage groups to produce IFN-β can still destroy HPV-infected cells.

Basaloid squamous cell carcinoma of the breast

Basaloid squamous cell carcinoma (BSCC) is a subtype of squamous cell carcinoma that characteristically occurs in the head and neck, may be related to HPV infection and is usually considered to be aggressive. We present the first description of BSCC of the breast. The tumor exhibited characteristic histologic features of BSCC, including nests of basaloid squamous cells with comedonecrosis, abrupt keratinization, and abundant hyaline basement membrane-like material deposition. The tumor showed immunohistochemical features of triple negativity, diffuse p63 positivity, p16 positivity, and Rb negativity. HPV immunogenotyping was negative. The patient was free of disease after treatment with breast conserving surgery, chemotherapy and radiotherapy. BSCC of the breast should be distinguished from basaloid adenoid cystic carcinoma, triple-negative basal-like breast cancer and nonbasaloid squamous cell carcinoma of the breast based on histology and immunohistochemistry. The prognostic implications of BSCC of the breast should be further studied in larger series.

Analysis of Nucleotide Alterations in the E6 Genomic Region of Human Papillomavirus Types 6 and 11 in Condyloma Acuminatum Samples from Brazil

Condyloma acuminata (CA), or genital warts, are benign proliferative epidermal or mucous lesions that are caused by infection with human papillomavirus (HPV), mainly the low-risk types 6 and 11. HPV variants are defined as viral sequences that share identity in the nucleotide sequence of the L1 gene greater than 98%. Based on this criterion, HPV6 and 11 variant lineages have been studied, and there are ongoing attempts to correlate these genetic variants with different clinical findings of infection. Therefore, the aims of this study were to detect variants and nucleotide alterations present in the E6 regions of HPV types 6 and 11 found in CA samples, to correlate the HPV presence with the clinical-pathological data of the patients, and to determine phylogenetic relationships with variants from other places in the world. The E6 regions of 25 HPV6 samples and 7 HPV11 samples from CA were amplified using PCR with specific primers. The products were ligated to a cloning vector and five colonies of each sample were sequenced to observe the nucleotide alterations. Twelve samples were identified as the HPV6B3 variant, presenting the mutation (guanine) G474A (adenine), and one of them also showed the mutation (thymine) T369G. The other 13 patients were positive for HPV6B1 without nucleotide alterations. In the analysis of the HPV11 samples, all patients showed the mutations T137C and (cytosine) C380T. One patient also presented the nucleotide alteration T410C. None of the mutations found in the 32 analyzed samples resulted in amino acid changes. Patient age, local occurrence, and HIV infection did not show significant association with HPV infection. Besides, the data found in this study did not show a relationship with the geographical region of isolation when compared to other data from different regions of the world. In this way, despite the nucleotide alterations found, it was not possible to observe amino acid changes and variants grouping according to geographical region.

Viral metagenomics updated the prevalence of human papillomavirus types in anogenital warts

To investigate the composition of human papillomavirus (HPV) types in anogenital warts (AGWs), viral nucleic acid in 110 AGWs, pooled into 11 specimen pools, were subjected to viral metagenomic analysis. After finding HPV7 in AGWs, conventional PCR screening was performed for HPV7 in other 190 individual AGW specimens. Viral metagenomic results indicated that 29 different types of HPV were recovered, with HPV11 and HPV6 showing the highest proportion of sequence reads. HPV7 was detected in 7 of 11 pools, 5 of which contained abundant HPV7 sequence reads. 24 complete genomes of HPV were acquired in viral metagenomic analysis, including 5 HPV7 genomes, based on which phylogenetic analysis and pairwise sequence comparison were conducted. PCR screening for HPV7 in other 190 individual AGW specimens revealed 25 positive cases (13.16%), of which the amplified fragments were sequenced and confirmed to be HPV7 sequences. Although HPV7 was generally found in hand warts and recently also in warts in toe webs, our data suggested that the role of HPV7 in AGW should be considered in the future clinical test and vaccine development for AGWs.

Prevalence of HPV infection in hypopharyngeal and laryngeal squamous cell carcinoma at Thailand's largest tertiary referral center

BACKGROUND

Following the well-established relationship between human papillomavirus (HPV) and cervical carcinoma, the carcinogenicity of this virus has also been confirmed in subsets of head and neck carcinoma (HNCA), but mainly in the oropharynx. Other subsites of HNCA with less known association to HPV have never been studied in Thailand. Accordingly, the aim of this study was to investigate the prevalence of HPV DNA in hypopharyngeal and laryngeal squamous cell carcinoma in Thai population.

METHODS

This cross-sectional study included hypopharyngeal and laryngeal squamous cell carcinoma patients diagnosed and treated at the Department of Otorhinolaryngology, Siriraj Hospital during the September 2011-December 2013 study period. Presence of HPV genome was confirmed by polymerase chain reaction from pathologically-confirmed fresh specimens. Demographic data and risk factors of HPV infection were evaluated.

RESULTS

Eighty patients were included, and 95% of those were male. Only one patient was noted with positive HPV-62 serotype. Most patients consumed tobacco and/or alcohol. Five patients had no risk factors for cancer development. Risk of HPV infection was evaluated by self-reporting questionnaire. The mean age of sexual debut was 20.17 years. Forty-eight patients had multiple sexual partners. Sixteen and seven patients had history of sexually transmitted disease infection and habitual oral sex contact, respectively.

CONCLUSION

There was no oncogenic HPV DNA detected within pathologic specimens of laryngeal and hypopharyngeal cancers in this study. Compared to rates reported from developed countries, the prevalence of HPV-related HNCA in Thailand is very low.

Squamous intraepithelial lesions of the anal squamocolumnar junction: Histopathological classification and HPV genotyping

Background

Human papillomavirus (HPV)-related anal cancer lesions are often found adjacent to the squamocolumnar junction (SCJ). We have assessed the histopathology and associated HPV genotypes in anal SCJ lesions in surgically excised anal warts in HIV-negative and –positive patients.

Methods

Histopathology identified 47 squamous intraepithelial lesions (SILs) adjacent to the SCJ amongst a total of 145 cases of clinically diagnosed anal condylomata. The anal SCJ lesions were further analyzed with p16, CK7 and p63 immunohistochemistry and HPV genotyping.

Results

Sixteen (16/47) of the excised anal wart lesions contained HSIL; Three were HSIL and exclusively associated with oncogenic HPVs. A further thirteen (13/47) were mixed lesions. Of these eight were HSILs with LSIL and six were HSILs with papillary immature metaplasia (PIM); Ten of the mixed lesions were associated with one or more oncogenic HPVs, while three cases were exclusively associated with HPV6.

Conclusions

Clinically diagnosed anal warts cannot be assumed to be limited to low-grade lesions as anal warts of the SCJ often show heterogeneous lesions, with coexistence of LSIL, PIM, and HSIL. Lesions showing PIM, however, may mimic HSIL, because they are hypercellular, but lack the nuclear atypia and conspicuous mitotic activity of HSIL; and are p16 negative.

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Anal warts of the SCJ are often heterogeneous; with LSIL, including PIM and HSIL.

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Anal HSILs only with HPV6 may indicate that LR-HPVs have some role in oncogenesis.

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Recognition of PIM is important given its potential for being confused with HSIL.

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Clinical diagnosis of anal warts cannot be assumed to be limited to LSIL.

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Microscopic examination of anal warts is encouraged with appropriate immunostains.

Global Genomic Diversity of Human Papillomavirus 11 Based on 433 Isolates and 78 Complete Genome Sequences

Human papillomavirus 11 (HPV11) is an etiological agent of anogenital warts and laryngeal papillomas and is included in the 4-valent and 9-valent prophylactic HPV vaccines. We established the largest collection of globally circulating HPV11 isolates to date and examined the genomic diversity of 433 isolates and 78 complete genomes (CGs) from six continents. The genomic variation within the 2,800-bp E5a-E5b-L1-upstream regulatory region was initially studied in 181/207 (87.4%) HPV11 isolates collected for this study. Of these, the CGs of 30 HPV11 variants containing unique single nucleotide polymorphisms (SNPs), indels (insertions or deletions), or amino acid changes were fully sequenced. A maximum likelihood tree based on the global alignment of 78 HPV11 CGs (30 CGs from our study and 48 CGs from GenBank) revealed two HPV11 lineages (lineages A and B) and four sublineages (sublineages A1, A2, A3, and A4). HPV11 (sub)lineage-specific SNPs within the CG were identified, as well as the 208-bp representative region for CG-based phylogenetic clustering within the partial E2 open reading frame and noncoding region 2. Globally, sublineage A2 was the most prevalent, followed by sublineages A1, A3, and A4 and lineage B.

IMPORTANCE

This collaborative international study defined the global heterogeneity of HPV11 and established the largest collection of globally circulating HPV11 genomic variants to date. Thirty novel complete HPV11 genomes were determined and submitted to the available sequence repositories. Global phylogenetic analysis revealed two HPV11 variant lineages and four sublineages. The HPV11 (sub)lineage-specific SNPs and the representative region identified within the partial genomic region E2/noncoding region 2 (NCR2) will enable the simpler identification and comparison of HPV11 variants worldwide. This study provides an important knowledge base for HPV11 for future studies in HPV epidemiology, evolution, pathogenicity, prevention, and molecular assay development.