Model Of Human Papillomavirus Research Articles

On the fractional order model for HPV and Syphilis using non–singular kernel

Most dynamical systems employ the classical integer-order derivatives which yield good results. However, recent trends have shown that the application of arbitrary order derivatives, popularly known as fractional order derivatives produces better and more realistic results to a given real life scenario because they are non-local operators. In this work, a fractional order co-infection model for human papilloma virus (HPV) and Syphilis is considered and studied using the non-singular kernel derivative. With the aid of Banach and Schauder’s fixed point theorems, the existence and uniqueness of the solution is proven. The conditions for the existence and uniqueness of the solution of the model are also established. The model’s disease free equilibrium (DFE) is shown to be locally asymptotically stable when the reproduction number is below one. The fractional order model is shown to be generalized Ulam Hyers–Rassias stable, under some conditions. The predictor–corrector method with convergence of min2,1+φ was used for the numerical simulations. Simulations of the model showed that the fractional derivative greatly influenced the dynamics of both diseases and their co-infection. Furthermore, it was observed that control strategy for single infection (syphilis only prevention strategy or HPV only prevention strategy) did not result in reduction of single infection cases, instead reduces the co-infection of new cases.

Physiologic and molecular characterization of a novel murine model of metastatic head and neck cancer cachexia.

BackgroundCancer cachexia is a metabolic disorder characterized by the progressive loss of fat and lean mass that results in significant wasting, ultimately leading to reduced quality of life and increased mortality. Effective therapies for cachexia are lacking, potentially owing to the mismatch in clinically relevant models of cachexia. Specifically, cachexia observed in a clinical setting is commonly associated with advanced or late‐stage cancers that are metastatic, yet pre‐clinical metastatic models of cachexia are limited. Furthermore, the prevalence of cachexia in head and neck cancer patients is high, yet few pre‐clinical models of head and neck cancer cachexia exist. In addition to these shortcomings, cachexia is also heterogeneous among any given cancer, whereas patients with similar disease burden may experience significantly different degrees of cachexia symptoms. In order to address these issues, we characterize a metastatic model of human papilloma virus (HPV) positive head and neck squamous cell carcinoma that recapitulates the cardinal clinical and molecular features of cancer cachexia.MethodsMale and female C57BL/6 mice were implanted subcutaneously with oropharyngeal squamous cell carcinoma cells stably transformed with HPV16 E6 and E7 together with hRas and luciferase (mEERL) that metastasizes to the lungs (MLM). We then robustly characterize the physiologic, behavioural, and molecular signatures during tumour development in two MLM subclones.ResultsMice injected with MLM tumour cells rapidly developed primary tumours and eventual metastatic lesions to the lungs. MLM3, but not MLM5, engrafted mice progressively lost fat and lean mass during tumour development despite the absence of anorexia (P < 0.05). Behaviourally, MLM3‐implanted mice displayed decreased locomotor behaviours and impaired nest building (P < 0.05). Muscle catabolism programmes associated with cachexia, including E3 ubiquitin ligase and autophagy up‐regulation, along with progressive adipose wasting and accompanying browning gene signatures, were observed. Tumour progression also corresponded with hypothalamic and peripheral organ inflammation, as well as an elevation in neutrophil‐to‐lymphocyte ratio (P < 0.05). Finally, we characterize the fat and lean mass sparing effects of voluntary wheel running on MLM3 cachexia (P < 0.05).ConclusionsThis syngeneic MLM3 allograft model of metastatic cancer cachexia is reliable, consistent, and readily recapitulates key clinical and molecular features and heterogeneity of cancer cachexia. Because few metastatic models of cachexia exist—even though cachexia often accompanies metastatic progression—we believe this model more accurately captures cancer cachexia observed in a clinical setting and thus is well suited for future mechanistic studies and pre‐clinical therapy development for this crippling metabolic disorder.

Using a Human Papillomavirus Model to Study DNA Replication and Repair of Wild Type and Damaged DNA Templates in Mammalian Cells

Human papillomaviruses have 8kbp DNA episomal genomes that replicate autonomously from host DNA. During initial infection, the virus increases its copy number to 20–50 copies per cell, causing torsional stress on the replicating DNA. This activates the DNA damage response (DDR) and HPV replicates its genome, at least in part, using homologous recombination. An active DDR is on throughout the HPV life cycle. Two viral proteins are required for replication of the viral genome; E2 binds to 12bp palindromic sequences around the A/T rich origin of replication and recruits the viral helicase E1 via a protein–protein interaction. E1 forms a di-hexameric complex that replicates the viral genome in association with host factors. Transient replication assays following transfection with E1–E2 expression plasmids, along with an origin containing plasmid, allow monitoring of E1-E2 replication activity. Incorporating a bacterial lacZ gene into the origin plasmid allows for the determination of replication fidelity. Here we describe how we exploited this system to investigate replication and repair in mammalian cells, including using damaged DNA templates. We propose that this system has the potential to enhance the understanding of cellular components involved in DNA replication and repair.

Abstract 4058: TheraT - a highly versatile arenavirus based vector platform for intravenous and intratumoral cancer immunotherapy

Abstract The unprecedented success of checkpoint blockade therapies clearly demonstrates the power of the immune system to fight cancer. Yet, only a minority of cancer patients respond with long-term control of the tumor or even cure, necessitating the development of other treatment modalities. Hookipa Pharma developed a novel attenuated, replication-competent viral vector platform (TheraT) that induces powerful cytotoxic T lymphocyte responses against foreign and self-antigens. In a preclinical model for human papilloma virus 16 (HPV16) associated cancer (TC-1), we evaluated immunogenicity and efficacy upon systemic and intratumoral application of TheraT vectors based on the arenaviruses lymphocytic choriomeningitis virus (LCMV) and pichinde virus (PICV). Both HB-201 (LCMV) and HB-202 (PICV) product candidates encode a non-oncogenic but highly antigenic E6/E7 fusion protein from HPV16. Independent of the route of administration, single administration of HB-201 or HB-202 induced potent peripheral E7-specific CD8+ T cell responses and led to efficient tumor growth control. Survival of TheraT treated animals was significantly longer compared to buffer treated animals. Similarly, single systemic as well as intratumoral application of HB-201 or HB-202 induced major infiltration of CD8+ T cells into the tumor microenvironment. Combination of intravenous HB-201 and anti-PD1 was well tolerated but did not further enhance efficacy in this model, implicating the presence of other immune evasion factors. In conclusion, replication-attenuated TheraT is safe, highly immunogenic and shows excellent therapeutic efficacy after single intravenous and intratumoral application. These data underline the potential and versatility of this novel vector platform. Mechanistic studies in various mouse tumor models are underway. Phase 1/2 clinical trial initiation of HB-201 monotherapy is planned for end of 2019 and preparations for an IND filing for a combination trial of HB-201 and HB-202 in H1 2020 have been initiated. Citation Format: Josipa Raguz, Sarah Schmidt, Theresa Kleisner, Manuel Zerbs, Goran Bekic, Sonja Feher, Daniel Oeler, Felix Stemeseder, Ursula Berka, Bettina Kiefmann, Sophie Schulha, Igor Matushansky, Henning Lauterbach, Klaus Orlinger. TheraT - a highly versatile arenavirus based vector platform for intravenous and intratumoral cancer immunotherapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4058.

Anti-tumoral Effects of Recombinant Lactococcus lactis Strain Secreting IL-17A Cytokine.

Interleukin-17A (IL-17A) is a pro-inflammatory cytokine produced by TH17 cells that participates and contributes in host defense and autoimmune disease. We have recently reported antitumor properties of the probiotic strain of Lactobacillus casei BL23 in mice and TH17 cells was shown to play an important role in this beneficial effect. In order to better understand the role of IL-17A in cancer, we constructed a recombinant strain of Lactococcus lactis producing this cytokine and we determined its biological activity in: (i) a bioassay test for the induction of IL-6 production by murine fibroblasts 3T3 L1 cells line and (ii) in a mouse allograft model of human papilloma virus (HPV)-induced cancer. Our data show that recombinant L. lactis produces and efficiently secretes biologically active IL-17A cytokine. Interestingly, ∼26% of mice intranasally treated with L. lactis-IL-17A and challenged with TC-1 cells remained tumor free over the experiment, in contrast to control mice treated with the wild type strain of L. lactis which developed 100% of aggressive tumors. In addition, the median size of the ∼74% tumor-bearing mice treated with recombinant L. lactis-IL-17A, was significantly lower than mice treated with L. lactis-wt. Altogether, our results demonstrate that intranasal administration with L. lactis secreting IL-17A results in a partial protection against TC-1-induced tumors in mice, confirming antitumor effects of this cytokine in our cancer model.

Elucidating the Immune-Related Mechanisms by Which Probiotic Strain Lactobacillus casei BL23 Displays Anti-tumoral Properties.

We have recently described antitumor properties of Lactobacillus casei BL23 strain in both a mouse allograft model of human papilloma virus (HPV)-induced cancer and dimethylhydrazine-associated colorectal cancer. However, the mechanisms underlying these beneficial effects are still unknown. Interestingly, in vitro cellular models show that this bacterium is able to stimulate the production of high levels of IL-2. Because this cytokine has well-known antitumor properties, we decided to explore its role in the anti-cancer effects of BL23 using the HPV-induced cancer model. We found a negative correlation between IL-2 and tumor size confirming the necessity of IL-2 to protect from tumor development. Then, we blocked IL-2 synthesis using neutralizing monoclonal antibodies in mice that were challenged with lethal levels of tumor cells; this led to a significant reduction in the protective abilities of BL23. Next, we used a genetically modified strain of Lactococcus lactis to deliver exogenous IL-2 to the system, and in doing so, we were able to partially mimic the antitumor properties of BL23. Additionally, we showed the systemic role of T-cells in tumor protection through a negative correlation between tumor size and T-cells subpopulations and an increasement of BL23-specific local Foxp3 levels in tumor-bearing mice. Finally, we observed a negative correlation between tumor size and NK+ cells, but local recruitment of NK cells and cytotoxic activity appeared specific to BL23 treatment. Taken together, our data suggest that IL-2 signaling pathway plays an important role in the anti-tumoral effects of probiotic strain L. casei BL23. These results encourage further investigation in the use of probiotic strains for potential therapeutic applications to clinical practice, in particular for the treatment of colorectal cancer. Furthermore, our approach could be extended and applied to other potential beneficial microorganisms, such as gut microbiota, in order to better understand the crosstalk between microbes and the host.

Abstract 5668: CCL2/CCR2-driven monocyte recruitment to the tumor following radiotherapy influences the outcome of the treatment of head and neck cancer

Abstract Local radiotherapy is the major treatment to control locally advanced head and neck cancer. Evidence supporting the importance of immune response in the response to radiation therapy is growing and the possibility to potentiate the effects of radiotherapy by modulating the function of the immune system offers new exciting therapeutic perspectives. Preclinical findings suggest that immunomodulatory agents may synergize with radiotherapy, increasing local response rates and inducing sustained systemic responses. The role of monocytes/macrophages in the response to radiotherapy is under extensive investigation. Among the many cytokines secreted by tumor cells, CCL2 is involved in inflammatory monocyte recruitment from bone marrow to the inflammatory site. We have recently developed a model of human papillomavirus (HPV)-related head and neck cancer using immunocompetent mice and validated its usefulness to evaluate the tumor response to radiotherapy. Using the same model, based on the injection of TC1/luciferase cells in the inner lip of C57Bl/6 mice, we show that local radiotherapy induces an increase of CCL2 levels in the bloodstream and intratumorally accompanied by a neo-infiltration of monocytes in the tumor that subsequently differentiate into tumor-associated macrophages (TAM). When TC1/Luc cells were engrafted in CCL2-/- or CCR2-/- mice, the tumor response to radiotherapy and survival were improved. This was accompanied by an impaired infiltration of inflammatory monocytes, and a subsequent decrease of TAM levels at later time points. In vitro, exposure to ionizing radiation increased the secretion of CCL2 by TC1/Luc cells, and such increase was significantly enhanced when tumor cells were co-cultured with irradiated RAW 264.7 macrophage-derived cells. This data suggests interplay between tumor and TAM that can amplify the effects of radiotherapy on the immune system. We propose that reducing radiation-induced monocyte recruitment may yield improved results in the treatment of HPV-related head and neck squamous cell carcinomas by radiotherapy. Immunologically-augmented radiotherapy could allow reduction of the delivered radiation dose, thus minimizing the risk of treatment sequelae while maintaining optimal tumor control. Citation Format: Michele Mondini, Pierre L. Loyher, Kevin Berthelot, Céline Clémenson, Alexandre Boissonnas, Eric Deutsch. CCL2/CCR2-driven monocyte recruitment to the tumor following radiotherapy influences the outcome of the treatment of head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5668. doi:10.1158/1538-7445.AM2017-5668

Neuroimmune mechanisms of behavioral alterations in a syngeneic murine model of human papilloma virus-related head and neck cancer

Patients with cancer often experience a high symptom burden prior to the start of treatment. As disease- and treatment-related neurotoxicities appear to be additive, targeting disease-related symptoms may attenuate overall symptom burden for cancer patients and improve the tolerability of treatment. It has been hypothesized that disease-related symptoms are a consequence of tumor-induced inflammation. We tested this hypothesis using a syngeneic heterotopic murine model of human papilloma virus (HPV)-related head and neck cancer. This model has the advantage of being mildly aggressive and not causing cachexia or weight loss. We previously showed that this tumor leads to increased IL-6, IL-1β, and TNF-α expression in the liver and increased IL-1β expression in the brain. The current study confirmed these features and demonstrated that the tumor itself exhibits high inflammatory cytokine expression (e.g., IL-6, IL-1β, and TNF-α) compared to healthy tissue. While there is a clear relationship between cytokine levels and behavioral deficits in this model, the behavioral changes are surprisingly mild. Therefore, we sought to confirm the relationship between behavior and inflammation by amplifying the effect using a low dose of lipopolysaccharide (LPS, 0.1mg/kg). In tumor-bearing mice LPS induced deficits in nest building, tail suspension, and locomotor activity approximately 24h after LPS. However, these mice did not display an exacerbation of LPS-induced weight loss, anorexia, or anhedonia. Further, while heightened serum IL-6 was observed there was minimal priming of liver or brain cytokine expression. Next we sought to inhibit tumor-induced burrowing deficits by reducing inflammation using minocycline. Minocycline (∼50mg/kg/day in drinking water) was able to attenuate tumor-induced inflammation and burrowing deficits. These data provide evidence in favor of an inflammatory-like mechanism for the behavioral alterations associated with tumor growth in a syngeneic murine model of HPV-related head and neck cancer. However, the inflammatory state and behavioral changes induced by this tumor clearly differ from other forms of inflammation-induced sickness behavior.

Measuring the Benefits of Healthcare: DALYs and QALYs - Does the Choice of Measure Matter? A Case Study of Two Preventive Interventions.

Background: The measurement of health benefits is a key issue in health economic evaluations. There is very scarce empirical literature exploring the differences of using quality-adjusted life years (QALYs) or disability-adjusted life years (DALYs) as benefit metrics and their potential impact in decision-making. Methods: Two previously published models delivering outputs in QALYs, were adapted to estimate DALYs: a Markov model for human papilloma virus (HPV) vaccination, and a pneumococcal vaccination deterministic model (PNEUMO). Argentina, Chile, and the United Kingdom studies were used, where local EQ-5D social value weights were available to provide local QALY weights. A primary study with descriptive vignettes was done (n = 73) to obtain EQ-5D data for all health states included in both models. Several scenario analyses were carried-out to evaluate the relative importance of using different metrics (DALYS or QALYs) to estimate health benefits on these economic evaluations. Results: QALY gains were larger than DALYs avoided in all countries for HPV, leading to more favorable decisions using the former. With discounting and age-weighting – scenario with greatest differences in all countries – incremental DALYs avoided represented the 75%, 68%, and 43% of the QALYs gained in Argentina, Chile, and United Kingdom respectively. Differences using QALYs or DALYs were less consistent and sometimes in the opposite direction for PNEUMO. These differences, similar to other widely used assumptions, could directly influence decision-making using usual gross domestic products (GDPs) per capita per DALY or QALY thresholds. Conclusion: We did not find evidence that contradicts current practice of many researchers and decision-makers of using QALYs or DALYs interchangeably. Differences attributed to the choice of metric could influence final decisions, but similarly to other frequently used assumptions.

Expression of fibronectin binding protein A (FnBPA) from Staphylococcus aureus at the cell surface of Lactococcus lactis improves its immunomodulatory properties when used as protein delivery vector

A recombinant strain of Lactococcus lactis displaying a cell-surface anchored fibronectin binding protein A (FnBPA) from Staphylococcus aureus (LL-FnBPA) had been shown to be more efficient in delivering plasmid than its wild-type counterpart both in vitro and in vivo, and have the ability to orientate the immune response toward a Th2 profile in a context of a DNA vaccination. The aim of this work was to test whether this LL-FnBPA strain could shape the immune response after mucosal administration in mice. For this, we used a mouse model of human papilloma virus (HPV)-induced cancer and a L. lactis strain displaying at its cell surface both HPV-16-E7 antigen (LL-E7) and FnBPA (LL-E7+FnBPA). Our results revealed a more efficient systemic Th1 immune response with recombinant LL-E7+FnBPA. Furthermore, mice vaccinated with LL-E7+FnBPA were better protected when challenged with HPV-16-induced tumors. Altogether, the results suggest that FnBPA displays adjuvant properties when used in the context of mucosal delivery using L. lactis as a live vector.

Sickness behavior induced by cisplatin chemotherapy and radiotherapy in a murine head and neck cancer model is associated with altered mitochondrial gene expression

The present study was undertaken to explore the possible mechanisms of the behavioral alterations that develop in response to cancer and to cancer therapy. For this purpose we used a syngeneic heterotopic mouse model of human papilloma virus (HPV)-related head and neck cancer in which cancer therapy is curative. Mice implanted or not with HPV+ tumor cells were exposed to sham treatment or a regimen of cisplatin and radiotherapy (chemoradiation). Sickness was measured by body weight loss and reduced food intake. Motivation was measured by burrowing, a highly prevalent species specific behavior. Tumor-bearing mice showed a gradual decrease in burrowing over time and increased brain and liver inflammatory cytokine mRNA expression by 28 days post tumor implantation. Chemoradiation administered to healthy mice resulted in a mild decrease in burrowing, body weight, and food intake. Chemoradiation in tumor-bearing mice decreased tumor growth and abrogated liver and brain inflammation, but failed to attenuate burrowing deficits. PCR array analysis of selected hypoxia and mitochondrial genes revealed that both the tumor and chemoradiation altered the expression of genes involved in mitochondrial energy metabolism within the liver and brain and increased expression of genes related to HIF-1α signaling within the brain. The most prominent changes in brain mitochondrial genes were noted in tumor-bearing mice treated with chemoradiation. These findings indicate that targeting mitochondrial dysfunction following cancer and cancer therapy may be a strategy for prevention of cancer-related symptoms.

SA-4-1BBL and monophosphoryl lipid A constitute an efficacious combination adjuvant for cancer vaccines.

Vaccines based on tumor-associated antigens (TAA) have limited therapeutic efficacy due to their weak immunogenic nature and the various immune evasion mechanisms active in advanced tumors. In an effort to overcome these limitations, we evaluated a combination of the T-cell costimulatory molecule SA-4-1BBL with the TLR4 agonist monophosphoryl lipid A (MPL) as a novel vaccine adjuvant system. In the TC-1 mouse allograft model of human papilloma virus (HPV)-induced cancer, a single administration of this combination adjuvant with HPV E7 protein caused tumor rejection in all tumor-bearing mice. On its own, SA-4-1BBL outperformed MPL in this setting. Against established tumors, two vaccinations were sufficient to elicit rejection in the majority of mice. In the metastatic model of Lewis lung carcinoma, vaccination of the TAA survivin with SA-4-1BBL/MPL yielded superior efficacy against pulmonary metastases. Therapeutic efficacy of SA-4-1BBL/MPL was achieved in the absence of detectable toxicity, correlating with enhanced dendritic cell activation, CD8(+) T-cell function, and an increased intratumoral ratio of CD8(+) T effector cells to CD4(+)FoxP3(+) T regulatory cells. Unexpectedly, use of MPL on its own was associated with unfavorable intratumoral ratios of these T-cell populations, resulting in suboptimal efficacy. The efficacy of MPL monotherapy was restored by depletion of T regulatory cells, whereas eliminating CD8(+) T cells abolished the efficacy of its combination with SA-4-1BBL. Mechanistic investigations showed that IFNγ played a critical role in supporting the therapeutic effect of SA-4-1BBL/MPL. Taken together, our results offer a preclinical proof of concept for the use of a powerful new adjuvant system for TAA-based cancer vaccines.

A revision of sexual mixing matrices in models of sexually transmitted infection

Two sexual mixing matrices previously used in models of sexually transmitted infections (STIs) are intended to calculate the probability of sexual interaction between age groups and sexual behaviour subgroups. When these matrices are used to specify multiple criteria for how people select sexual partners (such as age group and sexual behaviour class), their conditional probability structure means that they have in practice been prone to misuse. We constructed revised mixing matrices that incorporate a corrected conditional probability structure and then used one of them to examine the effect of this revision on population modelling of STIs. Using a dynamic model of human papillomavirus (HPV) transmission as an example, we examined changes to estimates of HPV prevalence and the relative reduction in age-standardised HPV incidence after the commencement of publicly funded HPV vaccination in Australia. When all other model specifications were left unchanged, the revised mixing matrix initially led to estimates of age-specific oncogenic HPV prevalence that were up to 11% higher than our previous models at certain ages. After re-calibrating the model by modifying unobservable parameters characterising HPV natural history, the revised mixing matrix yielded similar estimates to our previous models, predicting that vaccination would lead to relative HPV incidence reductions of 43% and 85% by 2010 and 2050, respectively, compared with 43% and 86% using the unrevised mixing matrix formulation. Our revised mixing matrix offers a rigorous alternative to commonly used mixing matrices, which can be used to reliably and explicitly accommodate conditional probabilities, with appropriate re-calibration of unobservable model parameters.

Induction of MHC class I molecule cell surface expression and epigenetic activation of antigen‐processing machinery components in a murine model for human papilloma virus 16‐associated tumours

Epigenetic events play an important role in tumour progression and also contribute to escape of the tumour from immune surveillance. In this study, we investigated the up-regulation of major histocompatibility complex (MHC) class I surface expression on tumour cells by epigenetic mechanisms using a murine tumour cell line expressing human E6 and E7 human papilloma virus 16 (HPV16) oncogenes and deficient in MHC class I expression, as a result of impaired antigen-presenting machinery (APM). Treatment of the cells with the histone deacetylase inhibitor Trichostatin A, either alone or in combination with the DNA demethylating agent 5-azacytidine, induced surface re-expression of MHC class I molecules. Consequently, the treated cells became susceptible to lysis by specific cytotoxic T lymphocytes. Further analysis revealed that epigenetic induction of MHC class I surface expression was associated with the up-regulation of APM genes [transporter associated with antigen processing 1 (TAP-1), TAP-2, low-molecular-mass protein 2 (LMP-2) and LMP-7]. The results demonstrate that expression of the genes involved in APM are modulated by epigenetic mechanisms and suggest that agents modifying DNA methylation and/or histone acetylation have the potential to change the effectiveness of antitumour immune responses and therapeutically may have an impact on immunological output.