scholarly journals Expression of membrane type 1 matrix metalloproteinase in papillomavirus-positive cells: role of the human papillomavirus (HPV) 16 and HPV8 E7 gene products

2005 ◽  
Vol 86 (5) ◽  
pp. 1291-1296 ◽  
Author(s):  
Sigrun Smola-Hess ◽  
Jenny Pahne ◽  
Cornelia Mauch ◽  
Paola Zigrino ◽  
Hans Smola ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Cellular Proliferation ◽  
Human Keratinocytes ◽  
Hpv Infection ◽  
Host Cells ◽  
Primary Human Keratinocytes ◽  
E7 Gene ◽  
Membrane Type

Matrix metalloproteinases (MMPs) degrade extracellular matrix. They are involved in cellular proliferation, migration, angiogenesis, invasion and metastasis. MT-1 MMP, a membrane-bound MMP, is expressed in carcinomas of the uterine cervix in vivo. This type of cancer is associated with human papillomavirus (HPV) infection. Here it was shown that keratinocytes transformed with HPV16 or HPV18 in vitro, and HPV-positive cervical carcinoma cell lines, constitutively expressed MT-1 MMP. Expression of the E7 protein from the mucosal and cutaneous high-risk types HPV16 and HPV8, but not from the cutaneous low-risk type HPV1, was sufficient to induce MT-1 MMP expression in primary human keratinocytes and HaCaT cells. As a consequence, MMP-2 was activated. MT-1 MMP expression might play a role in the HPV life cycle by promoting proliferation of host cells and might contribute to their invasive phenotype during malignant progression.

scholarly journals Sp100 Provides Intrinsic Immunity against Human Papillomavirus Infection

mBio ◽  
2013 ◽  
Vol 4 (6) ◽  
Author(s):  
Wesley H. Stepp ◽  
Jordan M. Meyers ◽  
Alison A. McBride
Keyword(s):  
Human Papillomavirus ◽  
Dna Replication ◽  
Human Keratinocytes ◽  
Hpv Infection ◽  
Nuclear Bodies ◽  
Host Cells ◽  
Viral Transcription ◽  
Primary Human Keratinocytes ◽  
Dna Viruses ◽  
Hpv Dna

ABSTRACTMost DNA viruses associate with, and reorganize, nuclear domain 10 (ND10) bodies upon entry into the host nucleus. In this study, we examine the roles of the ND10 components PML, Sp100, and Daxx in the establishment of human papillomavirus type 18 (HPV18) infection of primary human keratinocytes. HPV18 DNA or HPV18 quasivirus was introduced into primary human keratinocytes depleted of each ND10 protein by small interfering RNA technology, and genome establishment was determined by using a quantitative immortalization assay and measurements of viral transcription and DNA replication. Keratinocyte depletion of Sp100 resulted in a substantial increase in the number of HPV18-immortalized colonies and a corresponding increase in viral transcription and DNA replication. However, Sp100 repressed viral transcription and replication only during the initial stages of viral establishment, suggesting that Sp100 acts as a repressor of incoming HPV DNA.IMPORTANCEThe intrinsic immune system provides a first-line defense against invading pathogens. Host cells contain nuclear bodies (ND10) that are important for antiviral defense, yet many DNA viruses localize here upon cell entry. However, viruses also disrupt, reorganize, and modify individual components of the bodies. In this study, we show that one of the ND10 components, Sp100, limits the infection of human skin cells by human papillomavirus (HPV). HPVs are important pathogens that cause many types of infection of the cutaneous and mucosal epithelium and are the causative agents of several human cancers. Understanding how host cells counteract HPV infection could provide insight into antimicrobial therapies that could limit initial infection.

scholarly journals ADAR1 function affects HPV replication and is associated to recurrent human papillomavirus-induced dysplasia in HIV coinfected individuals

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maria Pujantell ◽  
Roger Badia ◽  
Iván Galván-Femenía ◽  
Edurne Garcia-Vidal ◽  
Rafael de Cid ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Immune Activation ◽  
Hpv Infection ◽  
Innate Immune ◽  
Type I ◽  
Innate Immune Activation ◽  
Enhanced Expression

AbstractInfection by human papillomavirus (HPV) alters the microenvironment of keratinocytes as a mechanism to evade the immune system. A-to-I editing by ADAR1 has been reported to regulate innate immunity in response to viral infections. Here, we evaluated the role of ADAR1 in HPV infection in vitro and in vivo. Innate immune activation was characterized in human keratinocyte cell lines constitutively infected or not with HPV. ADAR1 knockdown induced an innate immune response through enhanced expression of RIG-I-like receptors (RLR) signaling cascade, over-production of type-I IFNs and pro-inflammatory cytokines. ADAR1 knockdown enhanced expression of HPV proteins, a process dependent on innate immune function as no A-to-I editing could be identified in HPV transcripts. A genetic association study was performed in a cohort of HPV/HIV infected individuals followed for a median of 6 years (range 0.1–24). We identified the low frequency haplotype AACCAT significantly associated with recurrent HPV dysplasia, suggesting a role of ADAR1 in the outcome of HPV infection in HIV+ individuals. In summary, our results suggest that ADAR1-mediated innate immune activation may influence HPV disease outcome, therefore indicating that modification of innate immune effectors regulated by ADAR1 could be a therapeutic strategy against HPV infection.

scholarly journals Inhibition of Calcineurin/NFAT Signaling Blocks Oncogenic H-Ras Induced Autophagy in Primary Human Keratinocytes

2021 ◽  
Vol 9 ◽  
Author(s):  
Shuangshuang Wang ◽  
Hua Qian ◽  
Liwei Zhang ◽  
Panpan Liu ◽  
Dexuan Zhuang ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Human Keratinocytes ◽  
Primary Human Keratinocytes ◽  
Activated T Cells ◽  
Ras Pathway ◽  
Ras Family ◽  
Interfering Rna

Mutations of H-Ras, a member of the RAS family, are preferentially found in cutaneous squamous cell carcinomas (SCCs). H-Ras has been reported to induce autophagy, which plays an essential role in tissue homeostasis in multiple types of cancer cells and in fibroblasts, however, the potential role of H-Ras in regulating autophagy in human keratinocytes has not been reported. In this study, we found that the stable expression of the G12V mutant of H-RAS (H-RasG12V) induced autophagy in human keratinocytes, and interestingly, the induction of autophagy was strongly blocked by inhibiting the calcineurin/nuclear factor of activated T cells (NFAT) pathway with either a calcineurin inhibitor (Cyclosporin A) or a NFAT inhibitor (VIVIT), or by the small interfering RNA (siRNA) mediated knockdown of calcineurin B1 or NFATc1 in vitro, as well as in vivo. To characterize the role of the calcineurin/NFAT pathway in H-Ras induced autophagy, we found that H-RasG12V promoted the nuclear translocation of NFATc1, an indication of the activation of the calcineurin/NFAT pathway, in human keratinocytes. However, activation of NFATc1 either by the forced expression of NFATc1 or by treatment with phenformin, an AMPK activator, did not increase the formation of autophagy in human keratinocytes. Further study revealed that inhibiting the calcineurin/NFAT pathway actually suppressed H-Ras expression in H-RasG12V overexpressing cells. Finally, chromatin immunoprecipitation (ChIP) assays showed that NFATc1 potentially binds the promoter region of H-Ras and the binding efficiency was significantly enhanced by the overexpression of H-RasG12V, which was abolished by treatment with the calcineurin/NFAT pathway inhibitors cyclosporine A (CsA) or VIVIT. Taking these data together, the present study demonstrates that the calcineurin/NFAT signaling pathway controls H-Ras expression and interacts with the H-Ras pathway, involving the regulation of H-Ras induced autophagy in human keratinocytes.

scholarly journals A protein phosphatase network controls the temporal and spatial dynamics of differentiation commitment in human epidermis

2017 ◽  
Author(s):  
Ajay Mishra ◽  
Angela Oliveira Pisco ◽  
Benedicte Oules ◽  
Tony Ly ◽  
Kifayathullah Liakath-Ali ◽  
...  
Keyword(s):  
Stem Cell ◽  
Terminal Differentiation ◽  
Human Keratinocytes ◽  
Cell Renewal ◽  
Stable States ◽  
Primary Human Keratinocytes ◽  
Network Modelling ◽  
Epidermal Homeostasis

AbstractEpidermal homeostasis depends on a balance between stem cell renewal and terminal differentiation1,2. While progress has been made in characterising the stem and differentiated cell compartments3, the transition between the two cell states, termed commitment4, is poorly understood. Here we characterise commitment by integrating transcriptomic and proteomic data from disaggregated primary human keratinocytes held in suspension for up to 12h. We have previously shown that commitment begins at approximately 4h and differentiation is initiated by 8h5. We find that cell detachment induces a network of protein phosphatases. The pro-commitment phosphatases – including DUSP6, PPTC7, PTPN1, PTPN13 and PPP3CA – promote terminal differentiation by negatively regulating ERK MAPK and positively regulating key API transcription factors. Their activity is antagonised by concomitant upregulation of the anti-commitment phosphatase DUSP10. The phosphatases form a dynamic network of transient positive and negative interactions, with DUSP6 predominating at commitment. Boolean network modelling identifies a mandatory switch between two stable states (stem cell and differentiated cell) via an unstable (committed) state. In addition phosphatase expression is spatially regulated relative to the location of stem cells, both in vivo and in response to topographical cues in vitro. We conclude that an auto-regulatory phosphatase network maintains epidermal homeostasis by controlling the onset and duration of commitment.

scholarly journals Downregulation of Bax mRNA expression and protein stability by the E6 protein of human papillomavirus 16

2005 ◽  
Vol 86 (3) ◽  
pp. 611-621 ◽  
Author(s):  
Sharon Shnitman Magal ◽  
Anna Jackman ◽  
Shahar Ish-Shalom ◽  
Liat Edri Botzer ◽  
Pinhas Gonen ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Protein Stability ◽  
Mrna Expression ◽  
Human Keratinocytes ◽  
Dependent Manner ◽  
Primary Human Keratinocytes ◽  
Experimental Conditions ◽  
Human Papillomavirus 16 ◽  
Bax Protein

Previous studies have shown that human papillomavirus (HPV) 16 E6 inhibits apoptosis induced during terminal differentiation of primary human keratinocytes (PHKs) triggered by serum and calcium. E6 inhibition of apoptosis was accompanied with prolonged expression of Bcl-2 and reduced elevation of Bax levels. In the present study, the effect of E6 on Bax mRNA expression and protein stability was investigated. These studies indicate that stable E6 expression in differentiating keratinocytes reduced the steady-state levels of Bax mRNA and shortened the half-life of Bax protein. These results were confirmed in transiently transfected 293T cells where E6 degraded Bax in a dose-dependent manner. Bax degradation was also exhibited in Saos-2 cells that lack p53, indicating its p53 independence. E6 did not form complexes with Bax and did not induce Bax degradation in vitro under experimental conditions where p53 was degraded. Finally, E6 aa 120–132 were shown to be necessary for Bax destabilization and, more importantly, for abrogating the ability of Bax to induce cellular apoptosis, highlighting the functional consequences of the E6-induced alterations in Bax expression.

scholarly journals Skin Hyperproliferation and Susceptibility to Chemical Carcinogenesis in Transgenic Mice Expressing E6 and E7 of Human Papillomavirus Type 38

2005 ◽  
Vol 79 (23) ◽  
pp. 14899-14908 ◽  
Author(s):  
Wen Dong ◽  
Ulrich Kloz ◽  
Rosita Accardi ◽  
Sandra Caldeira ◽  
Wei-Min Tong ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Human Papillomavirus ◽  
Transgenic Mice ◽  
Cellular Proliferation ◽  
Cell Cycle Checkpoints ◽  
In Vivo Model ◽  
Primary Human Keratinocytes ◽  
Viral Genes ◽  
E6 And E7

ABSTRACT The oncoproteins E6 and E7 of human papillomavirus type 38 (HPV38) display several transforming activities in vitro, including immortalization of primary human keratinocytes. To evaluate the oncogenic activities of the viral proteins in an in vivo model, we generated transgenic mice expressing HPV38 E6 and E7 under the control of the bovine homologue of the human keratin 10 (K10) promoter. Two distinct lines of HPV38 E6/E7-expressing transgenic mice that express the viral genes at different levels were obtained. In both lines, HPV38 E6 and E7 induced cellular proliferation, hyperplasia, and dysplasia in the epidermis. The rate of occurrence of these events was proportional to the levels of HPV38 E6 and E7 expression in the two transgenic lines. Exposure of the epidermis of nontransgenic mice to UV led to p21WAF1 accumulation and cell cycle arrest. In contrast, keratinocytes from transgenic mice continued to proliferate and were not positive for p21WAF1, indicating that cell cycle checkpoints are altered in keratinocytes expressing the viral genes. Although the HPV38 E6/E7-expressing transgenic mice did not develop spontaneous tumors during their life span, two-stage carcinogen treatment led to a high incidence of papillomas, keratoacanthomas, and squamous-cell carcinomas in HPV38 mice compared with nontransgenic animals. Together, these data show that HPV38 E6 and E7 display transforming properties in vivo, providing further support for the role of HPV38 in carcinogenesis.

scholarly journals Differential Efficacy of Novel Antiviral Substances in 3D and Monolayer Cell Culture

Viruses ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1294
Author(s):  
Robert Koban ◽  
Markus Neumann ◽  
Philipp P. Nelson ◽  
Heinz Ellerbrok
Keyword(s):  
Cell Culture ◽  
Antiviral Activity ◽  
Virus Replication ◽  
3D Culture ◽  
Human Keratinocytes ◽  
Infection Model ◽  
Cowpox Virus ◽  
Primary Human Keratinocytes

Repurposing of approved drugs that target host functions also important for virus replication promises to overcome the shortage of antiviral therapeutics. Mostly, virus biology including initial screening of antivirals is studied in conventional monolayer cells. The biology of these cells differs considerably from infected tissues. 3D culture models with characteristics of human tissues may reflect more realistically the in vivo events during infection. We screened first, second, and third generation epidermal growth factor receptor (EGFR)-inhibitors with different modes of action and the EGFR-blocking monoclonal antibody cetuximab in a 3D cell culture infection model with primary human keratinocytes and cowpox virus (CPXV) for antiviral activity. Antiviral activity of erlotinib and osimertinib was nearly unaffected by the cultivation method similar to the virus-directed antivirals tecovirimat and cidofovir. In contrast, the host-directed inhibitors afatinib and cetuximab were approx. 100-fold more efficient against CPXV in the 3D infection model, similar to previous results with gefitinib. In summary, inhibition of EGFR-signaling downregulates virus replication comparable to established virus-directed antivirals. However, in contrast to virus-directed inhibitors, in vitro efficacy of host-directed antivirals might be seriously affected by cell cultivation. Results obtained for afatinib and cetuximab suggest that screening of such drugs in standard monolayer culture might underestimate their potential as antivirals.

scholarly journals In Vitro Expansion of Keratinocytes on Human Dermal Fibroblast-Derived Matrix Retains Their Stem-Like Characteristics

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chee-Wai Wong ◽  
Catherine F. LeGrand ◽  
Beverley F. Kinnear ◽  
Radoslaw M. Sobota ◽  
Rajkumar Ramalingam ◽  
...  
Keyword(s):  
Dermal Fibroblast ◽  
Human Keratinocytes ◽  
Dermal Fibroblasts ◽  
Collagen I ◽  
Matrix Composition ◽  
Major Influence ◽  
Primary Human Keratinocytes ◽  
Matrix Deposition

AbstractThe long-term expansion of keratinocytes under conditions that avoid xenogeneic components (i.e. animal serum- and feeder cell-free) generally causes diminished proliferation and increased terminal differentiation. Here we present a culture system free of xenogeneic components that retains the self-renewal capacity of primary human keratinocytes. In vivo the extracellular matrix (ECM) of the tissue microenvironment has a major influence on a cell’s fate. We used ECM from human dermal fibroblasts, cultured under macromolecular crowding conditions to facilitate matrix deposition and organisation, in a xenogeneic-free keratinocyte expansion protocol. Phospholipase A2 decellularisation produced ECM whose components resembled the core matrix composition of natural dermis by proteome analyses. Keratinocytes proliferated rapidly on these matrices, retained their small size, expressed p63, lacked keratin 10 and rarely expressed keratin 16. The colony forming efficiency of these keratinocytes was enhanced over that of keratinocytes grown on collagen I, indicating that dermal fibroblast-derived matrices maintain the in vitro expansion of keratinocytes in a stem-like state. Keratinocyte sheets formed on such matrices were multi-layered with superior strength and stability compared to the single-layered sheets formed on collagen I. Thus, keratinocytes expanded using our xenogeneic-free protocol retained a stem-like state, but when triggered by confluence and calcium concentration, they stratified to produce epidermal sheets with a potential clinical use.

scholarly journals Interaction of Zyxin, a Focal Adhesion Protein, with the E6 Protein from Human Papillomavirus Type 6 Results in Its Nuclear Translocation

2001 ◽  
Vol 75 (23) ◽  
pp. 11791-11802 ◽  
Author(s):  
Yan Yan Degenhardt ◽  
Saul Silverstein
Keyword(s):  
Human Papillomavirus ◽  
Focal Adhesion ◽  
Nuclear Translocation ◽  
Human Keratinocytes ◽  
Adhesion Protein ◽  
Lim Domains ◽  
Focal Adhesion Protein ◽  
E6 Protein

ABSTRACT Zyxin, a focal adhesion molecule, interacts specifically with the E6 protein from human papillomavirus (HPV) type 6 in a yeast two-hybrid screen of a cDNA library prepared from human keratinocytes. Zyxin does not interact significantly with E6 proteins from HPV types 11, 16, or 18. The interaction was confirmed by in vitro and in vivo analyses and it requires the LIM domains (Lin-11, Isl-1, and Mec-3 [G. Freyd, S. K. Kim, and H. R. Horvitz, Nature 344:876–879, 1990]) found at the carboxyl terminus of zyxin. Cotransfection of E6 from HPV (6E6) and zyxin results in the accumulation of zyxin in the nucleus where it can function as a transcriptional activator. 6E6 can also mobilize endogenous zyxin to the nucleus.

scholarly journals The E6 and E7 Proteins of the Cutaneous Human Papillomavirus Type 38 Display Transforming Properties

2003 ◽  
Vol 77 (3) ◽  
pp. 2195-2206 ◽  
Author(s):  
Sandra Caldeira ◽  
Ingeborg Zehbe ◽  
Rosita Accardi ◽  
Ilaria Malanchi ◽  
Wen Dong ◽  
...  
Keyword(s):  
Human Keratinocytes ◽  
Human Papillomaviruses ◽  
Host Cells ◽  
Primary Human Keratinocytes ◽  
Transition Control ◽  
Skin Cancers ◽  
E6 And E7 ◽  
E7 Proteins ◽  
Nonmelanoma Skin Cancers

ABSTRACT Several studies have suggested the involvement of cutaneous human papillomaviruses (HPVs) in the development of nonmelanoma skin cancers. Here we have characterized the in vitro properties of E7 proteins of three cutaneous HPV types, 10, 20, and 38, which are frequently detected in skin specimens. We show that HPV38 E7 is able to inactivate the tumor suppressor pRb and induces loss of G1/S transition control, a key event in carcinogenesis. In contrast, HPV10 and HPV20 E7 proteins do not display these in vitro transforming activities. We also show that the two early proteins E6 and E7 of HPV38 are sufficient to corrupt the cell cycle and senescence programs in primary cells, inducing active and long-lasting proliferation of primary human keratinocytes, the natural host cells. Our study shows that E6 and E7 of this cutaneous HPV type have transforming activity in primary human cells, suggesting a role for HPV38 infection in skin carcinogenesis. In further support of such a role, we detected HPV38 DNA in approximately 50% of nonmelanoma skin cancers, but only in 10% of healthy skin specimens (P < 0.001).

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