RESUMO
We study a patient with the human papilloma virus (HPV)-2-driven "tree-man" phenotype and two relatives with unusually severe HPV4-driven warts. The giant horns form an HPV-2-driven multifocal benign epithelial tumor overexpressing viral oncogenes in the epidermis basal layer. The patients are unexpectedly homozygous for a private CD28 variant. They have no detectable CD28 on their T cells, with the exception of a small contingent of revertant memory CD4+ T cells. T cell development is barely affected, and T cells respond to CD3 and CD2, but not CD28, costimulation. Although the patients do not display HPV-2- and HPV-4-reactive CD4+ T cells in vitro, they make antibodies specific for both viruses in vivo. CD28-deficient mice are susceptible to cutaneous infections with the mouse papillomavirus MmuPV1. The control of HPV-2 and HPV-4 in keratinocytes is dependent on the T cell CD28 co-activation pathway. Surprisingly, human CD28-dependent T cell responses are largely redundant for protective immunity.
Assuntos
Antígenos CD28/deficiência , Padrões de Herança/genética , Papillomaviridae/fisiologia , Pele/virologia , Linfócitos T/imunologia , Adulto , Sequência de Aminoácidos , Animais , Sequência de Bases , Antígenos CD28/genética , Antígenos CD28/metabolismo , Linfócitos T CD4-Positivos/imunologia , Criança , Endopeptidases/metabolismo , Feminino , Genes Recessivos , Células HEK293 , Homozigoto , Humanos , Imunidade Humoral , Memória Imunológica , Células Jurkat , Queratinócitos/patologia , Masculino , Camundongos Endogâmicos C57BL , Oncogenes , Papiloma/patologia , Papiloma/virologia , Linhagem , Sinais Direcionadores de Proteínas , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Cell-penetrating peptides (CPPs) are short protein segments that can transport cargos into cells. Although CPPs are widely studied as potential drug delivery tools, their role in normal cell physiology is poorly understood. Early during infection, the L2 capsid protein of human papillomaviruses binds retromer, a cytoplasmic trafficking factor required for delivery of the incoming non-enveloped virus into the retrograde transport pathway. Here, we show that the C terminus of HPV L2 proteins contains a conserved cationic CPP that drives passage of a segment of the L2 protein through the endosomal membrane into the cytoplasm, where it binds retromer, thereby sorting the virus into the retrograde pathway for transport to the trans-Golgi network. These experiments define the cell-autonomous biological role of a CPP in its natural context and reveal how a luminal viral protein engages an essential cytoplasmic entry factor.
Assuntos
Proteínas do Capsídeo/metabolismo , Peptídeos Penetradores de Células/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Sequência de Aminoácidos , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Peptídeos Penetradores de Células/química , Peptídeos Penetradores de Células/genética , Endossomos/metabolismo , Complexo de Golgi/virologia , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Células HeLa , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/fisiologia , Humanos , Mutagênese , Proteínas Oncogênicas Virais/química , Proteínas Oncogênicas Virais/genética , Transporte Proteico , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Alinhamento de Sequência , Ligação Viral , Internalização do VírusRESUMO
Although most cervical human papillomavirus type 16 (HPV16) infections become undetectable within 1-2 years, persistent HPV16 causes half of all cervical cancers. We used a novel HPV whole-genome sequencing technique to evaluate an exceptionally large collection of 5,570 HPV16-infected case-control samples to determine whether viral genetic variation influences risk of cervical precancer and cancer. We observed thousands of unique HPV16 genomes; very few women shared the identical HPV16 sequence, which should stimulate a careful re-evaluation of the clinical implications of HPV mutation rates, transmission, clearance, and persistence. In case-control analyses, HPV16 in the controls had significantly more amino acid changing variants throughout the genome. Strikingly, E7 was devoid of variants in precancers/cancers compared to higher levels in the controls; we confirmed this in cancers from around the world. Strict conservation of the 98 amino acids of E7, which disrupts Rb function, is critical for HPV16 carcinogenesis, presenting a highly specific target for etiologic and therapeutic research.
Assuntos
Alphapapillomavirus/genética , Alphapapillomavirus/isolamento & purificação , Carcinoma/virologia , Infecções por Papillomavirus/virologia , Neoplasias do Colo do Útero/virologia , Adulto , Alphapapillomavirus/classificação , Estudos de Casos e Controles , Feminino , Genoma Viral , Humanos , Pessoa de Meia-Idade , Proteínas E7 de Papillomavirus/genética , Polimorfismo de Nucleotídeo Único , Adulto JovemRESUMO
Compounds binding to the bromodomains of bromodomain and extra-terminal (BET) family proteins, particularly BRD4, are promising anticancer agents. Nevertheless, side effects and drug resistance pose significant obstacles in BET-based therapeutics development. Using high-throughput screening of a 200,000-compound library, we identified small molecules targeting a phosphorylated intrinsically disordered region (IDR) of BRD4 that inhibit phospho-BRD4 (pBRD4)-dependent human papillomavirus (HPV) genome replication in HPV-containing keratinocytes. Proteomic profiling identified two DNA damage response factors-53BP1 and BARD1-crucial for differentiation-associated HPV genome amplification. pBRD4-mediated recruitment of 53BP1 and BARD1 to the HPV origin of replication occurs in a spatiotemporal and BRD4 long (BRD4-L) and short (BRD4-S) isoform-specific manner. This recruitment is disrupted by phospho-IDR-targeting compounds with little perturbation of the global transcriptome and BRD4 chromatin landscape. The discovery of these protein-protein interaction inhibitors (PPIi) not only demonstrates the feasibility of developing PPIi against phospho-IDRs but also uncovers antiviral agents targeting an epigenetic regulator essential for virus-host interaction and cancer development.
Assuntos
Infecções por Papillomavirus , Fatores de Transcrição , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Papillomavirus Humano , Infecções por Papillomavirus/tratamento farmacológico , Infecções por Papillomavirus/genética , Proteômica , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Papillomaviridae/genética , Papillomaviridae/metabolismo , Proteínas Virais/genética , Replicação Viral/fisiologia , Reparo do DNA , Proteínas que Contêm BromodomínioRESUMO
People living with HIV (PLWH) are at increased risk for developing skin and mucosal malignancies despite systemic reconstitution of CD4+ T cells upon antiretroviral therapy (ART). The underlying mechanism of chronic tissue-related immunodeficiency in HIV is unclear. We found that skin CD4+ tissue-resident memory T (Trm) cells were depleted after HIV infection and replenished only upon early ART initiation. TCR clonal analysis following early ART suggested a systemic origin for reconstituting CD4+ Trm cells. Single-cell RNA sequencing in PLWH that received late ART treatment revealed a loss of CXCR3+ Trm cells and a tolerogenic skin immune environment. Human papilloma virus-induced precancerous lesion biopsies showed reduced CXCR3+ Trm cell frequencies in the mucosa in PLWH versus HIV- individuals. These results reveal an irreversible loss of CXCR3+ Trm cells confined to skin and mucosa in PLWH who received late ART treatment, which may be a precipitating factor in the development of HPV-related cancer.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1/fisiologia , Síndromes de Imunodeficiência/imunologia , Células T de Memória/imunologia , Mucosa/imunologia , Pele/imunologia , Adulto , Terapia Antirretroviral de Alta Atividade , Feminino , Infecções por HIV/tratamento farmacológico , Sobreviventes de Longo Prazo ao HIV , Humanos , Síndromes de Imunodeficiência/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Receptores CXCR3/metabolismo , Análise de Sequência de RNA , Análise de Célula Única , Tempo para o Tratamento , Adulto JovemRESUMO
Human papillomavirus (HPV) is currently linked to almost 35,000 new cases of cancer in women and men each year in the United States. Gardasil-9 (Merck & Company), the only HPV vaccine now available in the United States, is nearly 100% effective at preventing precancers caused by oncogenic HPV types. In the United States, however, only about one half of adolescents are up to date with HPV vaccination. It is well known that health care clinicians' recommendations play a significant role in parents' decisions regarding HPV vaccination. A growing body of literature examines specific communication strategies for promoting uptake of the HPV vaccine. A comprehensive review of the evidence for each of these strategies is needed. The authors searched the PubMed, EMBASE, Cochrane Central Register of Controlled Trials, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, and Web of Science Complete databases for original articles with a defined clinician communication strategy and an outcome of HPV vaccine uptake or intention to vaccinate (PROSPERO registry no. CRD42020107602). In total, 46 studies were included. The authors identified two main strategies with strong evidence supporting their positive impact on vaccine uptake: strong recommendation and presumptive recommendation. Determinations about a causal relationship were limited by the small numbers of randomized controlled trials. There is also opportunity for more research to determine the effects of motivational interviewing and cancer-prevention messaging.
Assuntos
Alphapapillomavirus , Neoplasias , Infecções por Papillomavirus , Vacinas contra Papillomavirus , Adolescente , Masculino , Feminino , Humanos , Estados Unidos , Infecções por Papillomavirus/prevenção & controle , Infecções por Papillomavirus/complicações , Vacinas contra Papillomavirus/uso terapêutico , Vacinação , Comunicação , Pais , Neoplasias/prevenção & controleRESUMO
Despite being highly preventable, cervical cancer is the fourth most common cancer and cause of cancer death in women globally. In low-income countries, cervical cancer is often the leading cause of cancer-related morbidity and mortality. Women living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome are at a particularly high risk of cervical cancer because of an impaired immune response to human papillomavirus, the obligate cause of virtually all cervical cancers. Globally, approximately 1 in 20 cervical cancers is attributable to HIV; in sub-Saharan Africa, approximately 1 in 5 cervical cancers is due to HIV. Here, the authors provide a critical appraisal of the evidence to date on the impact of HIV disease on cervical cancer risk, describe key methodologic issues, and frame the key outstanding research questions, especially as they apply to ongoing global efforts for prevention and control of cervical cancer. Expanded efforts to integrate HIV care with cervical cancer prevention and control, and vice versa, could assist the global effort to eliminate cervical cancer as a public health problem.
Assuntos
Infecções por HIV/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/prevenção & controle , Detecção Precoce de Câncer , Feminino , Humanos , Hospedeiro Imunocomprometido , Infecções por Papillomavirus , Vacinas contra Papillomavirus , Lesões Pré-Cancerosas/terapia , Prevenção Primária , Prevenção SecundáriaRESUMO
Cervical cancer is caused by human papillomavirus (HPV) infection, has few approved targeted therapeutics, and is the most common cause of cancer death in low-resource countries. We characterized 19 cervical and four head and neck cancer cell lines using long-read DNA and RNA sequencing and identified the HPV types, HPV integration sites, chromosomal alterations, and cancer driver mutations. Structural variation analysis revealed telomeric deletions associated with DNA inversions resulting from breakage-fusion-bridge (BFB) cycles. BFB is a common mechanism of chromosomal alterations in cancer, and our study applies long-read sequencing to this important chromosomal rearrangement type. Analysis of the inversion sites revealed staggered ends consistent with exonuclease digestion of the DNA after breakage. Some BFB events are complex, involving inter- or intra-chromosomal insertions or rearrangements. None of the BFB breakpoints had telomere sequences added to resolve the dicentric chromosomes, and only one BFB breakpoint showed chromothripsis. Five cell lines have a chromosomal region 11q BFB event, with YAP1-BIRC3-BIRC2 amplification. Indeed, YAP1 amplification is associated with a 10-year-earlier age of diagnosis of cervical cancer and is three times more common in African American women. This suggests that individuals with cervical cancer and YAP1-BIRC3-BIRC2 amplification, especially those of African ancestry, might benefit from targeted therapy. In summary, we uncovered valuable insights into the mechanisms and consequences of BFB cycles in cervical cancer using long-read sequencing.
Assuntos
Infecções por Papillomavirus , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/genética , Aberrações Cromossômicas , Telômero/genética , DNARESUMO
The American Cancer Society (ACS) presents an adaptation of the current Advisory Committee on Immunization Practices recommendations for human papillomavirus (HPV) vaccination. The ACS recommends routine HPV vaccination between ages 9 and 12 years to achieve higher on-time vaccination rates, which will lead to increased numbers of cancers prevented. Health care providers are encouraged to start offering the HPV vaccine series at age 9 or 10 years. Catch-up HPV vaccination is recommended for all persons through age 26 years who are not adequately vaccinated. Providers should inform individuals aged 22 to 26 years who have not been previously vaccinated or who have not completed the series that vaccination at older ages is less effective in lowering cancer risk. Catch-up HPV vaccination is not recommended for adults aged older than 26 years. The ACS does not endorse the 2019 Advisory Committee on Immunization Practices recommendation for shared clinical decision making for some adults aged 27 through 45 years who are not adequately vaccinated because of the low effectiveness and low cancer prevention potential of vaccination in this age group, the burden of decision making on patients and clinicians, and the lack of sufficient guidance on the selection of individuals who might benefit.
Assuntos
Esquemas de Imunização , Vacinação em Massa/normas , Neoplasias/prevenção & controle , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/administração & dosagem , Adolescente , Adulto , Comitês Consultivos/normas , Alphapapillomavirus/imunologia , Alphapapillomavirus/patogenicidade , American Cancer Society/organização & administração , Criança , Competência Clínica , Feminino , Pessoal de Saúde/educação , Implementação de Plano de Saúde/organização & administração , Implementação de Plano de Saúde/normas , Humanos , Colaboração Intersetorial , Vacinação em Massa/organização & administração , Pessoa de Meia-Idade , Neoplasias/patologia , Neoplasias/virologia , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Estados Unidos , Cobertura Vacinal/organização & administração , Cobertura Vacinal/normas , Adulto JovemRESUMO
Over the past few decades, with the rise of immunotherapies, tumor infiltrating immune cells were increasingly investigated. Indeed, they may represent biomarkers for patient outcome prediction, they may bear immune checkpoint markers that can be targeted by therapeutic antibodies and mechanistic studies may reveal how to tweak their activation profile so that we can re-direct them towards tumor cells. Macrophages possess a central place in tissue homeostasis for tissue remodeling and cleaning, transformed cell elimination, phagocytosis and regulation of inflammation via cytokine production. All these functions allow the discovery of approaches to target Tumor Associated Macrophages (TAMs) using immunotherapies. Indeed, TAMs express known immune checkpoint markers such as PD-L1, CD40, Sirp-α and markers such as CD163, CD204, TREM2, TREM1 associated with prognosis. In the context of therapies TAM may participate to antibody dependent cell phagocytosis (ADCP) thanks to FCγ-Receptors. Here, we will review the recent literature on TAMs in the specific context of HPV+ tumors. Indeed, HPV infection of mucosal tissue may lead to head and neck, cervical, penile, anal and vaginal cancers. HPV+ tumors exhibit a higher immune cell infiltrate, which relies on inflammation, immunosuppression and anti-viral response. In this context, and considering the many functions on macrophages, we will show the versatility of TAMs in a tumor microenvironment with viral infection features.
Assuntos
Neoplasias , Infecções por Papillomavirus , Feminino , Humanos , Macrófagos Associados a Tumor , Terapia de Imunossupressão , Biomarcadores , Inflamação , Microambiente TumoralRESUMO
High-risk human papilloma viruses (HPVs) cause cervical, anal, and oropharyngeal cancers, unlike the low-risk HPVs, which cause benign lesions. E6 oncoproteins from the high-risk strains are essential for cell proliferation and transformation in HPV-induced cancers. We report that a cellular deubiquitinase, USP46, is selectively recruited by the E6 of high-risk, but not low-risk, HPV to deubiqutinate and stabilize Cdt2/DTL. Stabilization of Cdt2, a component of the CRL4Cdt2 E3 ubiquitin ligase, limits the level of Set8, an epigenetic writer, and promotes cell proliferation. USP46 is essential for the proliferation of HPV-transformed cells, but not of cells without HPV. Cdt2 is elevated in human cervical cancers and knockdown of USP46 inhibits HPV-transformed tumor growth in xenografts. Recruitment of a cellular deubiquitinase to stabilize key cellular proteins is an important activity of oncogenic E6, and the importance of E6-USP46-Cdt2-Set8 pathway in HPV-induced cancers makes USP46 a target for the therapy of such cancers.
Assuntos
Endopeptidases/genética , Papillomavirus Humano 16/genética , Papillomavirus Humano 18/genética , Proteínas Nucleares/genética , Infecções por Papillomavirus/genética , Neoplasias do Colo do Útero/genética , Animais , Ciclo Celular , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Endopeptidases/metabolismo , Feminino , Regulação da Expressão Gênica , Células HeLa , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Interações Hospedeiro-Patógeno/genética , Papillomavirus Humano 16/metabolismo , Papillomavirus Humano 16/patogenicidade , Papillomavirus Humano 18/metabolismo , Papillomavirus Humano 18/patogenicidade , Humanos , Injeções Intralesionais , Camundongos , Proteínas Nucleares/metabolismo , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/enzimologia , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Neoplasias do Colo do Útero/enzimologia , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The activity of proteins is thought to be invariably determined by their amino acid sequence or composition, but we show that a long segment of a viral protein can support infection independent of its sequence or composition. During virus entry, the papillomavirus L2 capsid protein protrudes through the endosome membrane into the cytoplasm to bind cellular factors such as retromer required for intracellular virus trafficking. Here, we show that an ~110 amino acid segment of L2 is predicted to be disordered and that large deletions in this segment abolish infectivity of HPV16 pseudoviruses by inhibiting cytoplasmic protrusion of L2, association with retromer, and proper virus trafficking. The activity of these mutants can be restored by insertion of protein segments with diverse sequences, compositions, and chemical properties, including scrambled amino acid sequences, a tandem array of a short sequence, and the intrinsically disordered region of an unrelated cellular protein. The infectivity of mutants with small in-frame deletions in this segment directly correlates with the size of the segment. These results indicate that the length of the disordered segment, not its sequence or composition, determines its activity during HPV16 pseudovirus infection. We propose that a minimal length of L2 is required for it to protrude far enough into the cytoplasm to bind cytoplasmic trafficking factors, but the sequence of this segment is largely irrelevant. Thus, protein segments can carry out complex biological functions such as Human papillomavirus pseudovirus infection in a sequence-independent manner. This finding has important implications for protein function and evolution.
Assuntos
Proteínas Oncogênicas Virais , Infecções por Papillomavirus , Humanos , Proteínas do Capsídeo/química , Papillomavirus Humano , Internalização do Vírus , Células HeLa , Capsídeo/metabolismo , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/químicaRESUMO
R-loops are trimeric RNA: DNA hybrids that are important physiological regulators of transcription; however, their aberrant formation or turnover leads to genomic instability and DNA breaks. High-risk human papillomaviruses (HPV) are the causative agents of genital as well as oropharyngeal cancers and exhibit enhanced amounts of DNA breaks. The levels of R-loops were found to be increased up to 50-fold in cells that maintain high-risk HPV genomes and were readily detected in squamous cell cervical carcinomas in vivo but not in normal cells. The high levels of R-loops in HPV-positive cells were present on both viral and cellular sites together with RNase H1, an enzyme that controls their resolution. Depletion of RNase H1 in HPV-positive cells further increased R-loop levels, resulting in impaired viral transcription and replication along with reduced expression of the DNA repair genes such as FANCD2 and ATR, both of which are necessary for viral functions. Overexpression of RNase H1 decreased total R-loop levels, resulting in a reduction of DNA breaks by over 50%. Furthermore, increased RNase H1 expression blocked viral transcription and replication while enhancing the expression of factors in the innate immune regulatory pathway. This suggests that maintaining elevated R-loop levels is important for the HPV life cycle. The E6 viral oncoprotein was found to be responsible for inducing high levels of R-loops by inhibiting p53's transcriptional activity. Our studies indicate that high R-loop levels are critical for HPV pathogenesis and that this depends on suppressing the p53 pathway.
Assuntos
Carcinoma de Células Escamosas , Anemia de Fanconi , Infecções por Papillomavirus , Humanos , Estruturas R-Loop , Proteína Supressora de Tumor p53/genética , Infecções por Papillomavirus/genéticaRESUMO
We analyzed transcriptional data from 104 HPV+ (Human papillomavirus) HNSCC (head and neck squamous cell carcinoma) tumors together with two publicly available sources to identify highly robust transcriptional programs (modules) which could be detected consistently despite heterogeneous sequencing and quantification methodologies. Among 22 modules identified, we found a single module that naturally subclassifies HPV+ HNSCC tumors based on a bimodal pattern of gene expression, clusters all atypical features of HPV+ HNSCC biology into a single subclass, and predicts patient outcome in four independent cohorts. The subclass-defining gene set was strongly correlated with Nuclear factor kappa B (NF-κB) target expression. Tumors with high expression of this NF-κB module were rarely associated with activating PIK3CA alterations or viral integration, and also expressed higher levels of HPHPV E2 and had decreased APOBEC mutagenesis. Alternatively, they harbored inactivating alterations of key regulators of NF-κB, TNF receptor associated factor 3 (TRAF3), and cylindromatosis (CYLD), as well as retinoblastoma protein (RB1). HPV+ HNSCC cells in culture with experimental depletion of TRAF3 or CYLD displayed increased expression of the subclass-defining genes, as well as robust radio-sensitization, thus recapitulating both the tumor transcriptional state and improved treatment response observed in patient data. Across all gene sets investigated, methylation to expression correlations were the strongest for the subclass-defining, NF-κB-related genes. Increased tumor-infiltrating CD4+ T cells and increased Estrogen receptors alpha (ERα) expression were identified in NF-κB active tumors. Based on the relatively high rates of cure in HPV+ HNSCC, deintensification of therapy to reduce treatment-related morbidity is being studied at many institutions. Tumor subclassification based on oncogenic subtypes may help guide the selection of therapeutic intensity or modality for patients with HPV+ HNSCC.
Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Infecções por Papillomavirus , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/radioterapia , NF-kappa B/genética , NF-kappa B/metabolismo , Fator 3 Associado a Receptor de TNF/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/metabolismo , Infecções por Papillomavirus/genética , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/radioterapia , Papillomavirus Humano , Carcinogênese , Papillomaviridae/genética , Papillomaviridae/metabolismoRESUMO
Three-stranded DNA-RNA structures known as R-loops that form during papillomavirus transcription can cause transcription-replication conflicts and lead to DNA damage. We found that R-loops accumulated at the viral early promoter in human papillomavirus (HPV) episomal cells but were greatly reduced in cells with integrated HPV genomes. RNA-DNA helicases unwind R-loops and allow for transcription and replication to proceed. Depletion of the RNA-DNA helicase senataxin (SETX) using siRNAs increased the presence of R-loops at the viral early promoter in HPV-31 (CIN612) and HPV-16 (W12) episomal HPV cell lines. Depletion of SETX reduced viral transcripts in episomal HPV cell lines. The viral E2 protein, which binds with high affinity to specific palindromes near the promoter and origin, complexes with SETX, and both SETX and E2 are present at the viral p97 promoter in CIN612 and W12 cells. SETX overexpression increased E2 transcription activity on the p97 promoter. SETX depletion also significantly increased integration of viral genomes in CIN612 cells. Our results demonstrate that SETX resolves viral R-loops to proceed with HPV transcription and prevent genome integration.IMPORTANCEPapillomaviruses contain small circular genomes of approximately 8 kilobase pairs and undergo unidirectional transcription from the sense strand of the viral genome. Co-transcriptional R-loops were recently reported to be present at high levels in cells that maintain episomal HPV and were also detected at the early viral promoter. R-loops can inhibit transcription and DNA replication. The process that removes R-loops from the PV genome and the requisite enzymes are unknown. We propose a model in which the host RNA-DNA helicase senataxin assembles on the HPV genome to resolve R-loops in order to maintain the episomal status of the viral genome.
RESUMO
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-ß) 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-ß can still destroy HPV-infected cells.
Assuntos
Papillomavirus Humano 11 , Proteínas E7 de Papillomavirus , Infecções por Papillomavirus , Infecções Respiratórias , Adulto , Feminino , Humanos , Masculino , Células Epiteliais/virologia , Células Epiteliais/imunologia , Papillomavirus Humano 11/genética , Papillomavirus Humano 11/imunologia , Evasão da Resposta Imune , Imunidade Inata , Interferon beta/metabolismo , Interferon beta/imunologia , Interferon beta/genética , Macrófagos/imunologia , Macrófagos/virologia , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Proteínas E7 de Papillomavirus/metabolismo , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/imunologia , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Infecções Respiratórias/virologia , Infecções Respiratórias/imunologiaRESUMO
Oncogenic HPV E6 proteins have a PDZ-binding motif (PBM) which plays important roles in both the viral life cycle and tumor development. The PBM confers interaction with a large number of different PDZ domain-containing substrates, one of which is Sorting Nexin 27. This protein is part of the retromer complex and plays an important role in endocytic sorting pathways. It has been shown that at least two SNX27 interacting partners, GLUT1 and TANC2, are aberrantly trafficked due to the E6 PBM-dependent interaction with SNX27. To investigate further which other components of the endocytic trafficking pathway might be affected by the SNX27-HPV E6 interaction, we analyzed the SNX27 proteome interaction profile in a previously described HeLa cell line expressing GFP-SNX27, both in the presence and absence of the HPV-18 E6 oncoprotein. In this study, we identify a novel interacting partner of SNX27, secreted glycoprotein EMILIN2, whose release is blocked by HPV18 E6 in a PBM-dependent manner. Mechanistically, E6 can block EMILIN2 interaction with the WNT1 ligand, thereby enhancing WNT1 signaling and promoting cell proliferation. IMPORTANCE: This study demonstrates that HPV E6 blocks EMILIN2 inhibition of WNT1 signaling, thereby enhancing cell proliferation in HPV-positive tumor cells. This involves a novel mechanism whereby the E6 PBM actually contributes toward enhancing the interaction between SNX27 and EMILIN2, suggesting that the mode of recognition of SNX27 by E6 and EMILIN2 is different. This is the first example of the E6 PBM altering a PDZ domain-containing protein to enhance potential substrate recognition.
Assuntos
Papillomavirus Humano 18 , Proteínas Oncogênicas Virais , Nexinas de Classificação , Via de Sinalização Wnt , Humanos , Nexinas de Classificação/metabolismo , Nexinas de Classificação/genética , Proteínas Oncogênicas Virais/metabolismo , Proteínas Oncogênicas Virais/genética , Células HeLa , Papillomavirus Humano 18/metabolismo , Papillomavirus Humano 18/genética , Ligação Proteica , Proteínas Repressoras/metabolismo , Proteínas Repressoras/genética , Domínios PDZ , Células HEK293 , Infecções por Papillomavirus/virologia , Infecções por Papillomavirus/metabolismo , Proteínas de Ligação a DNARESUMO
The human papillomavirus (HPV) oncoprotein E7 is a relatively short-lived protein required for HPV-driven cancer development and maintenance. E7 is degraded through ubiquitination mediated by cullin 1 (CUL1) and the ubiquitin-conjugating enzyme E2 L3 (UBE2L3). However, E7 proteins are maintained at high levels in most HPV-positive cancer cells. A previous proteomics study has shown that UBE2L3 and CUL1 protein levels are increased by the knockdown of the E3 ubiquitin ligase membrane-associated ring-CH-type finger 8 (MARCHF8). We have recently demonstrated that HPV16 upregulates MARCHF8 expression in HPV-positive keratinocytes and head and neck cancer (HPV+ HNC) cells. Here, we report that MARCHF8 stabilizes the HPV16 E7 protein by degrading the components of the S-phase kinase-associated protein 1-CUL1-F-box ubiquitin ligase complex in HPV+ HNC cells. We found that MARCHF8 knockdown in HPV+ HNC cells drastically decreases the HPV16 E7 protein level while increasing the CUL1 and UBE2L3 protein levels. We further revealed that the MARCHF8 protein binds to and ubiquitinates CUL1 and UBE2L3 proteins and that MARCHF8 knockdown enhances the ubiquitination of the HPV16 E7 protein. Conversely, the overexpression of CUL1 and UBE2L3 in HPV+ HNC cells decreases HPV16 E7 protein levels and suppresses tumor growth in vivo. Our findings suggest that HPV-induced MARCHF8 prevents the degradation of the HPV16 E7 protein in HPV+ HNC cells by ubiquitinating and degrading CUL1 and UBE2L3 proteins.IMPORTANCESince human papillomavirus (HPV) oncoprotein E7 is essential for virus replication; HPV has to maintain high levels of E7 expression in HPV-infected cells. However, HPV E7 can be efficiently ubiquitinated by a ubiquitin ligase and degraded by proteasomes in the host cell. Mechanistically, the E3 ubiquitin ligase complex cullin 1 (CUL1) and ubiquitin-conjugating enzyme E2 L3 (UBE2L3) components play an essential role in E7 ubiquitination and degradation. Here, we show that the membrane ubiquitin ligase membrane-associated ring-CH-type finger 8 (MARCHF8) induced by HPV16 E6 stabilizes the E7 protein by degrading CUL1 and UBE2L3 and blocking E7 degradation through proteasomes. MARCHF8 knockout restores CUL1 and UBE2L3 expression, decreasing E7 protein levels and inhibiting the proliferation of HPV-positive cancer cells. Additionally, overexpression of CUL1 or UBE2L3 decreases E7 protein levels and suppresses in vivo tumor growth. Our results suggest that HPV16 maintains high E7 protein levels in the host cell by inducing MARCHF8, which may be critical for cell proliferation and tumorigenesis.
Assuntos
Proteínas Culina , Neoplasias de Cabeça e Pescoço , Proteínas Oncogênicas Virais , Proteínas E7 de Papillomavirus , Infecções por Papillomavirus , Enzimas de Conjugação de Ubiquitina , Ubiquitina-Proteína Ligases , Humanos , Proteínas Culina/genética , Proteínas Culina/metabolismo , Neoplasias de Cabeça e Pescoço/genética , Papillomavirus Humano , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina/metabolismo , Enzimas de Conjugação de Ubiquitina/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
The role of numerous risk factors, including consumption of alcohol, smoking, having diet high in fat and sugar and many other items, on caner progression cannot be denied. Viral diseases are one these factors, and they can initiate some signalling pathways causing cancer. For example, they can be effective on providing oxygen and nutrients by inducing VEGF expression. In this review article, we summarised the mechanisms of angiogenesis and VEGF expression in cancerous tissues which are infected with oncoviruses (Epstein-Barr virus, Human papillomavirus infection, Human T-lymphotropic virus, Kaposi's sarcoma-associated herpesvirus, Hepatitis B and hepatitis C virus).
Assuntos
Infecções por Vírus Epstein-Barr , Fator A de Crescimento do Endotélio Vascular , Humanos , Infecções por Vírus Epstein-Barr/complicações , Herpesvirus Humano 4 , Herpesvirus Humano 8/genética , Neoplasias/etiologia , Fator A de Crescimento do Endotélio Vascular/genética , Viroses/complicaçõesRESUMO
A significant portion of human cancers are caused by oncoviruses (12%-25%). Oncoviruses employ various strategies to promote their replication and induce tumourigenesis in host cells, one of which involves modifying the gene expression patterns of the host cells, leading to the rewiring of genes and resulting in significant changes in cellular processes and signalling pathways. In recent studies, a specific mode of gene regulation known as circular RNA (circRNA)-mediated competing endogenous RNA (ceRNA) networks has emerged as a key player in this context. CircRNAs, a class of non-coding RNA molecules, can interact with other RNA molecules, such as mRNAs and microRNAs (miRNAs), through a process known as ceRNA crosstalk. This interaction occurs when circRNAs, acting as sponges, sequester miRNAs, thereby preventing them from binding to their target mRNAs and modulating their expression. By rewiring the host cell genome, oncoviruses have the ability to manipulate the expression and activity of circRNAs, thereby influencing the ceRNA networks that can profoundly impact cellular processes such as cell proliferation, differentiation, apoptosis, and immune responses. This review focuses on a comprehensive evaluation of the latest findings on the involvement of virus-induced reprogramming of host circRNA-mediated ceRNA networks in the development and pathophysiology of human viral cancers, including cervical cancer, gastric cancer, nasopharyngeal carcinoma, Kaposi's sarcoma, hepatocellular carcinoma, and diffuse large B cell lymphoma. Understanding these mechanisms can improve our knowledge of how oncoviruses contribute to human tumourigenesis and identify potential targets for developing optimised therapies and diagnostic tools for viral cancers.