A novel method to culture laryngeal human papillomavirus-positive epithelial cells produces papilloma-type cytology on collagen rafts

Preclinical Models of Laryngeal Papillomavirus Infection: A Scoping Review

OBJECTIVE

Laryngeal human papillomavirus (HPV) infection causes recurrent respiratory papillomatosis (RRP) and accounts for up to 25% of laryngeal cancers. Lack of satisfactory preclinical models is one reason that treatments for these diseases are limited. We sought to assess the literature describing preclinical models of laryngeal papillomavirus infection.

DATA SOURCES

PubMed, Web of Science, and Scopus were searched from the inception of database through October 2022.

REVIEW METHODS

Studies searched were screened by two investigators. Eligible studies were peer-reviewed, published in English, presented original data, and described attempted models of laryngeal papillomavirus infection. Data examined included type of papillomavirus, infection model, and results including success rate, disease phenotype, and viral retention.

RESULTS

After screening 440 citations and 138 full-text studies, 77 studies published between 1923 and 2022 were included. Models used low-risk HPV or RRP (n = 51 studies), high-risk HPV or laryngeal cancer (n = 16), both low- and high-risk HPV (n = 1), and animal papillomaviruses (n = 9). For RRP, 2D and 3D cell culture models and xenografts retained disease phenotypes and HPV DNA in the short term. Two laryngeal cancer cell lines were consistently HPV-positive in multiple studies. Animal laryngeal infections with animal papillomaviruses resulted in disease and long-term retention of viral DNA.

CONCLUSIONS

Laryngeal papillomavirus infection models have been researched for 100 years and primarily involve low-risk HPV. Most models lose viral DNA after a short duration. Future work is needed to model persistent and recurrent diseases, consistent with RRP and HPV-positive laryngeal cancer.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:3256-3268, 2023.

Pathogen-associated molecular patterns on biomaterials: a paradigm for engineering new vaccines

Vaccine development has progressed significantly and has moved from whole microorganisms to subunit vaccines that contain only their antigenic proteins. Subunit vaccines are often less immunogenic than whole pathogens; therefore, adjuvants must amplify the immune response, ideally establishing both innate and adaptive immunity. Incorporation of antigens into biomaterials, such as liposomes and polymers, can achieve a desired vaccine response. The physical properties of these platforms can be easily manipulated, thus allowing for controlled delivery of immunostimulatory factors and presentation of pathogen-associated molecular patterns (PAMPs) that are targeted to specific immune cells. Targeting antigen to immune cells via PAMP-modified biomaterials is a new strategy to control the subsequent development of immunity and, in turn, effective vaccination. Here, we review the recent advances in both immunology and biomaterial engineering that have brought particulate-based vaccines to reality.

Immune suppression in head and neck cancers: a review

Head and neck squamous cell carcinomas (HNSCCs) are the sixth most common cancer in the world. Despite significant advances in the treatment modalities involving surgery, radiotherapy, and concomitant chemoradiotherapy, the 5-year survival rate remained below 50% for the past 30 years. The worse prognosis of these cancers must certainly be link to the fact that HNSCCs strongly influence the host immune system. We present a critical review of our understanding of the HNSCC escape to the antitumor immune response such as a downregulation of HLA class I and/or components of APM. Antitumor responses of HNSCC patients are compromised in the presence of functional defects or apoptosis of T-cells, both circulating and tumor-infiltrating. Langerhans cells are increased in the first steps of the carcinogenesis but decreased in invasive carcinomas. The accumulation of macrophages in the peritumoral areas seems to play a protumoral role by secreting VEGF and stimulating the neoangiogenesis.

Development of a cellular assay system to study the genome replication of high- and low-risk mucosal and cutaneous human papillomaviruses

We found that recircularized high-risk (type 16 and 18) and low-risk mucosal (type 6b and 11) and cutaneous (type 5 and 8) human papillomavirus (HPV) genomes replicate readily when delivered into U2OS cells by electroporation. The replication efficiency is dependent on the amount of input HPV DNA and can be followed for more than 3 weeks in proliferating cell culture without selection. Cotransfection of recircularized HPV genomes with a linear G418 resistance marker plasmid has allowed subcloning of cell lines, which, in a majority of cases, carry multicopy episomal HPV DNA. Analysis of the HPV DNA status in these established cell lines showed that HPV genomes exist in these cells as stable extrachromosomal oligomers. When the cell lines were cultivated as confluent cultures, a 3- to 10-fold amplification of the HPV genomes per cell was induced. Two-dimensional (2D) agarose gel electrophoresis confirmed amplification of mono- and oligomeric HPV genomes in these confluent cell cultures. Amplification occurred as a result of the initiation of semiconservative two-dimensional replication from one active origin in the HPV oligomer. Our data suggest that the system described here might be a valuable, cost-effective, and efficient tool for use in HPV DNA replication studies, as well as for the design of cell-based assays to identify potential inhibitors of all stages of HPV genome replication.

[Papillomas & laryngeal papillomatosis. Treatment with CO₂ laser surgery. Our experience over 15 years]

OBJECTIVES

The study goal was to evaluate the efficacy of CO₂ laser surgery in the treatment of laryngeal papillomatosis. We analysed several parameters such as gender, average age, relapse rate and viral serotype.

MATERIAL AND METHODS

A total of 26 diagnosed patients were included in this retrospective descriptive review. All of them were treated with CO₂ laser for laryngeal papillomas between 1995 and 2010.

RESULTS

This pathology was more prevalent in males (65.5%), with a slight predominance of a single larynx localisation over multiple lesion locations. Human papillomavirus (HPV) DNA was detected in 75.8% of the cases; genotypes 6 and 11 prevailed. Of the patients in this review, 44.8% relapsed; the relapse average was 2-3 episodes per patient. A total of 20.7% of cases were in remission (no relapse in the last 2 months); 34.5%, clearing (no apparent relapse in the last 3 years); and 41.3% in the healing stage (without relapse in the last 5 years). There was only one case that showed malignancy.

CONCLUSION

Papillomatosis is characterised as a pathology with an unpredictable course and with a low probability of malignancy. CO₂ laser surgery has meant a revolution in symptomatic treatment, but there is presently no curative treatment.

Interaction of viral oncoproteins with cellular target molecules: infection with high-risk vs low-risk human papillomaviruses

Persistent infection by a subgroup of so-called high-risk human papillomaviruses (HPVs) that have a tropism for mucosal epithelia has been defined as the cause of more than 98% of cervical carcinomas as well as a high proportion of other cancers of the anogenital region. Infection of squamous epithelial tissues in the head and neck region by these same high-risk HPVs is also associated with a subset of cancers. Despite the general conservation of genetic structure amongst all HPV types, infection by the low-risk types, whether in genital or head and neck sites, carries a negligible risk of malignant progression, and infections have a markedly different pathology. In this review, we will examine and discuss the interactions that the principal viral oncoproteins of the high-risk mucosotrophic HPVs and their counterparts from the low-risk group make with cellular target proteins, with a view to explaining the differences in their respective pathology.

Identification of a novel human gammapapillomavirus species

By using random PCR amplification, shotgun sequencing and sequence similarity searches, we analysed nucleic acids present in cell cultures inoculated with samples from unexplained cases of encephalitis. We identified a divergent human papillomavirus (HPV) sequence originating from a rectal swab. The full genome was amplified by inverse PCR and sequenced. The prototype of the sixth gammapapillomavirus species, HPV116, was not found in the patient's cerebrospinal fluid or respiratory secretions, nor in culture supernatants from other unexplained cases of encephalitis, indicating that its identification in an encephalitis patient was accidental.

Koilocytosis: a cooperative interaction between the human papillomavirus E5 and E6 oncoproteins

A long-recognized, pathognomonic feature of human papillomavirus (HPV) infection is the appearance of halo or koilocytotic cells in the differentiated layers of the squamous epithelium. These koilocytes are squamous epithelial cells that contain an acentric, hyperchromatic nucleus that is displaced by a large perinuclear vacuole. However, the genesis of the cytoplasmic vacuole has remained unclear, particularly because both HPV DNA replication and virion assembly occur exclusively in the nucleus. In clinical biopsies, koilocytosis is observed in both low- and high-risk HPV infections; therefore, in this study, we demonstrated that the E5 and E6 proteins from both low- and high-risk HPVs cooperate to induce koilocyte formation in human cervical cells in vitro, using both stable and transient assays. Both E5 and E6 also induce koilocytosis in human foreskin keratinocytes but not in primate COS cells. Deletion of the 20 C-terminal amino acids of E5 completely abrogates koilocytosis, whereas a 10-amino acid-deletion mutant retains approximately 50% of its activity. Because the E6 protein from both the low- and high-risk HPVs is capable of potentiating koilocytosis with E5, it is apparent that the targeting of both p53 and PDZ proteins by E6 is not involved. Our data suggest new, cooperative functions for both the E5 and E6 proteins, hinting at additional targets and roles for these oncoproteins in the viral life cycle.

Recurrent respiratory papillomatosis: a review

Recurrent respiratory papillomatosis (RRP), which is caused by human papillomavirus types 6 and 11, is the most common benign neoplasm of the larynx among children and the second most frequent cause of childhood hoarseness. After changes in voice, stridor is the second most common symptom, first inspiratory and then biphasic. Less common presenting symptoms include chronic cough, recurrent pneumonia, failure to thrive, dyspnea, dysphagia, or acute respiratory distress, especially in infants with an upper respiratory tract infection. Differential diagnoses include asthma, croup, allergies, vocal nodules, or bronchitis. Reports estimate the incidence of RRP in the United States at 4.3 per 100,000 children and 1.8 per 100,000 adults. Infection in children has been associated with vertical transmission during vaginal delivery from an infected mother. Younger age at diagnosis is associated with more aggressive disease and the need for more frequent surgical procedures to decrease the airway burden. When surgical therapy is needed more frequently than four times in 12 months or there is evidence of RRP outside the larynx, adjuvant medical therapy should be considered. Adjuvant therapies that have been investigated include dietary supplements, control of extra-esophageal reflux disease, potent antiviral and chemotherapeutic agents, and photodynamic therapies; although several have shown promise, none to date has "cured" RRP, and some may have serious side effects. Because RRP, although histologically benign, is so difficult to control and can cause severe morbidity and death, better therapies are needed. The potential for a quadrivalent human papilloma vaccine is being explored to reduce the incidence of this disease.

Oral Cancer Cells Differ From Normal Oral Epithelial Cells in Tissuelike Organization and in Response to Lycopene Treatment: An Organotypic Cell Culture Study

We established distinctive monolayer and organotypic cell culture techniques to assess possible differences in cross-talk and spatial and structural organization of oral cancer cells compared with normal oral cells and also to evaluate possible differential responses of the cells to carotenoids. In monolayers, we investigated the effect of lycopene on the proliferation of an established oral cancer cell line, KB-1, and compared it with a primary cell line obtained from normal oral mucosa. Lycopene exerted a significant inhibitory effect on KB-1 cell proliferation inducing a dose-dependent downregulation of proliferating cell nuclear antigen (PCNA) associated with upregulation of connexin-43 (Cx-43) expression, whereas in the normal oral mucosal cells lycopene did not affect either PCNA expression, which was very low, or the expression of Cx-43, which was basically very high. Lycopene significantly inhibited the formation of colonies induced by the carcinogen 3-methylcholanthrene (MCA) on normal oral cells and almost completely abrogated the hyperplastic effect induced by MCA. KB-1 cells and normal oral epithelial cells in the organotypic cell culture method differed in their stratification and intercellular adhesion patterns as well as in the expression profile of cytokeratins, vimentin, and Cx-43. Lycopene induced Cx-43 expression in KB-1 cells grown by the organotypic raft method, similar to KB-1 cells grown as monolayers. We conclude that lycopene is a promising chemopreventive, pro-differentiating, and anticarcinogenic agent. No adverse effects of lycopene were detected in normal cells cultured in either monolayer or organotypic systems.

Establishment and characterisation of human papillomavirus type 16 DNA immortalised human tonsillar epithelial cell lines

Oncogenic human papillomavirus (HPV) plays a possible aetiological role in a subset of head and neck cancers, particularly in tonsillar carcinomas. For establishing a model to study mechanisms involved in HPV-associated tonsillar carcinogenesis, normal human tonsillar epithelial (HTE) cells were transfected with full-length HPV-16 DNA. The transfections produced four immortalised cell lines, designated HTE-114/K1, HTE-114/K2, HTE-114/K3 and HTE-114/B. All transfected HTE cell lines were cytogenetically abnormal. They exhibited altered morphology and impaired expression of cytokeratins in organotypic cultures. They failed to form colonies in soft agarose and formed no tumours in nude mice within 6 months. Each of them contained integrated viral DNA in a distinctive pattern as shown by Southern blot hybridisation. Early viral transcripts containing the E7 gene were detected by northern blot hybridisation. In conclusion, primary HTE cells can be immortalised following transfection with full-length HPV-16 DNA; the immortalised cell lines had partially retained epithelial characteristics in their morphology and function. They seem to represent early stages of premalignant epithelial cells and thus provide a useful model for studying further the multistep molecular events of HPV-16-associated tonsillar carcinogenesis.

Human papillomavirus in larynx

OBJECTIVES

The core of the present clinical and basic research knowledge of laryngeal human papillomavirus (HPV) infection is described.

STUDY DESIGN

Review.

METHODS

A computer-aided search of MEDLINE database supplemented by hand searches of key journals was conducted.

RESULTS

One of the tumor-promoting factors in the larynx is the HPV found both in normal laryngeal epithelium and in laryngeal tumors. The most important manifestation of laryngeal HPV infection is laryngeal papillomatosis, a rare disease caused by HPV types 6 and 11. In laryngeal carcinogenesis, the role of HPV remains uncertain. The means of transmission of HPV are partly unknown, and the course of laryngeal HPV infection is unpredictable and variable. Treatment of laryngeal papillomatosis is based on surgery, especially on CO2 laser and shaver. Alpha-interferon is the drug of choice in patients whose response to surgery is poor. However, neither interferon nor other antiviral drugs are able to eradicate the virus from laryngeal mucosa. Little is known about immunological mechanisms involved in laryngeal HPV infection, but in defense against HPV cellular immunity is considered a more important mechanism than humoral immunity. A good experimental model of HPV infection is lacking in which the entire viral life cycle can take place. Organotypic cell cultures (collagen rafts) are useful, but the rate-limiting step in this method is the difficulties in culturing HPV-positive epithelial cells.

CONCLUSIONS

Although laryngeal papillomatosis is clinically well defined, the mechanisms and treatment modalities of laryngeal HPV infection need further investigations.

Infection with Human Papillomavirus: Update on Epidemiology, Diagnosis, and Treatment

Human papillomavirus (HPV) infection is the most common sexually transmitted viral disease worldwide. Low-risk types of HPV (eg, HPV-6 and HPV-11) are the causative agents of genital warts, whereas high-risk types (eg, HPV-16 and HPV-18) have been associated with anogenital cancer, particularly cervical cancer. Cervical cancer remains the second most common cancer in women worldwide. Recent advances have led to a better understanding of how HPV causes cancer on a molecular level and of the immunologic response to HPV. Methods to detect HPV infection have been improved, and a new treatment method for genital warts has been developed. The production of empty capsids of HPV done using recombinant technology has led to the development of serologic assays for HPV. The empty capsids are now the basis of clinical trials of vaccines to prevent HPV infection and disease.