RESUMEN
In recent decades, recombinant antibodies against specific antigens have shown great promise for the therapy of infectious diseases and cancer. Human papillomaviruses (HPVs) are involved in the development of around 5% of all human cancers and HPV16 is the high-risk genotype with the highest prevalence worldwide, playing a dominant role in all HPV-associated cancers. Here, we describe the main biological activities of the HPV16 E6, E7, and E5 oncoproteins, which are involved in the subversion of important regulatory pathways directly associated with all known hallmarks of cancer. We then review the state of art of the recombinant antibodies targeted to HPV oncoproteins developed so far in different formats, and outline their mechanisms of action. We describe the advantages of a possible antibody-based therapy against the HPV-associated lesions and discuss the critical issue of delivery to tumour cells, which must be addressed in order to achieve the desired translation of the antibodies from the laboratory to the clinic.
Asunto(s)
Anticuerpos Antivirales/uso terapéutico , Neoplasias/tratamiento farmacológico , Anticuerpos de Dominio Único/uso terapéutico , Animales , Anticuerpos Antivirales/inmunología , Humanos , Neoplasias/virología , Proteínas Oncogénicas Virales/inmunología , Proteínas E7 de Papillomavirus/inmunología , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/uso terapéutico , Proteínas Represoras/inmunología , Anticuerpos de Dominio Único/inmunologíaRESUMEN
BACKGROUND: Ebola hemorrhagic fever is caused by the Ebola filovirus (EBOV), which is one of the most aggressive infectious agents known worldwide. The EBOV pathogenesis starts with uncontrolled viral replication and subversion of both the innate and adaptive host immune response. The multifunctional viral VP35 protein is involved in this process by exerting an antagonistic action against the early antiviral alpha/beta interferon (IFN-α/ß) response, and represents a suitable target for the development of strategies to control EBOV infection. Phage display technology permits to select antibodies as single chain Fragment variable (scFv) from an artificial immune system, due to their ability to specifically recognize the antigen of interest. ScFv is ideal for genetic manipulation and to obtain antibody constructs useful for targeting either antigens expressed on cell surface or intracellular antigens if the scFv is expressed as intracellular antibody (intrabody) or delivered into the cells. RESULTS: Monoclonal antibodies (mAb) in scFv format specific for the EBOV VP35 were isolated from the ETH-2 library of human recombinant antibodies by phage display technology. Five different clones were identified by sequencing, produced in E.coli and expressed in CHO mammalian cells to be characterized in vitro. All the selected scFvs were able to react with recombinant VP35 protein in ELISA, one of the scFvs being also able to react in Western Blot assay (WB). In addition, all scFvs were expressed in cell cytoplasm as intrabodies; a luciferase reporter gene inhibition assay performed in A549 cells showed that two of the scFvs can significantly hamper the inhibition of the IFN-ß-induced RIG-I signaling cascade mediated by EBOV VP35. CONCLUSION: Five antibodies in scFv format recognize an active form of EBOV VP35 in ELISA, while one antibody also recognizes VP35 in WB. Two of these scFvs were also able to interfere with the intracellular activity of VP35 in a cell system in vitro. These findings suggest that such antibodies in scFv format might be employed to develop therapeutic molecules able to hamper EBOV infections.
Asunto(s)
Filoviridae/inmunología , Filoviridae/patogenicidad , Fiebre Hemorrágica Ebola/inmunología , Anticuerpos de Cadena Única/inmunología , Anticuerpos Antivirales/inmunología , Humanos , Proteínas Virales/inmunologíaRESUMEN
Human papillomaviruses (HPVs) have been detected in urban wastewaters, demonstrating that epitheliotropic viruses can find their way into sewage through the washing of skin and mucous membranes. Papillomavirus shedding through faeces is still an unexplored issue. The objective of the present study was to investigate the presence of HPVs in stool samples. We analysed 103 faecal specimens collected from hospitalized patients with diarrhoea using validated primers able to detect α, ß and γ HPVs. PCR products underwent sequencing analysis and sequences were aligned to reference genomes from the Papillomavirus Episteme database. A total of 15 sequences were characterized from the faecal samples. Thirteen samples (12.6â%) were positive for nine genotypes belonging to the α and ß genera: HPV32 (LR, α1), HPV39 (HR, α7), HPV44 (LR, α10), HPV8 (ß1), HPV9, HPV23, HPV37, HPV38 and HPV120 (ß2). Two putative novel genotypes of the ß genus, species 1 and 2, were also detected. The tissue(s) of origin is unknown, since faeces can collect HPVs originating from or passing through the entire digestive system. To our knowledge, this is the first investigation on the occurrence and diversity of HPVs in faecal samples. Results from this study demonstrate that HPVs can find their way into sewage as a consequence of shedding in the faeces. This highlights the need for further studies aimed at understanding the prevalence of HPV in different water environments and the potential for waterborne transmission.
Asunto(s)
Alphapapillomavirus/aislamiento & purificación , Betapapillomavirus/aislamiento & purificación , Heces/virología , Infecciones por Papillomavirus/virología , Diarrea/virología , Humanos , Datos de Secuencia Molecular , Aguas Residuales/virologíaRESUMEN
Human papillomavirus (HPV)-associated tumors still represent an urgent problem of public health in spite of the efficacy of the prophylactic HPV vaccines. Specific antibodies in single-chain format expressed as intracellular antibodies (intrabodies) are valid tools to counteract the activity of target proteins. We previously showed that the M2SD intrabody, specific for the E7 oncoprotein of HPV16 and expressed in the endoplasmic reticulum of the HPV16-positive SiHa cells, was able to inhibit cell proliferation. Here, we showed by confocal microscopy that M2SD and E7 colocalize in the endoplasmic reticulum of SiHa cells, suggesting that the E7 delocalization mediated by M2SD could account for the anti-proliferative activity of the intrabody. We then tested the M2SD antitumor activity in two mouse models for HPV tumors based respectively on TC-1 and C3 cells. The M2SD intrabody was delivered by retroviral vector to tumor cells before cell injection into C57BL/6 mice. In both models, a marked delay of tumor onset with respect to the controls was observed in all the mice injected with the M2SD-expressing tumor cells and, importantly, a significant percentage of mice remained tumor-free permanently. This is the first in vivo demonstration of the antitumor activity of an intrabody directed towards an HPV oncoprotein. We consider that these results could contribute to the development of new therapeutic molecules based on antibodies in single-chain format, to be employed against the HPV-associated lesions even in combination with other drugs.
Asunto(s)
Anticuerpos Antivirales/administración & dosificación , Papillomavirus Humano 16/inmunología , Proteínas E7 de Papillomavirus/antagonistas & inhibidores , Infecciones por Papillomavirus/terapia , Anticuerpos de Cadena Única/administración & dosificación , Neoplasias del Cuello Uterino/terapia , Animales , Anticuerpos Antivirales/genética , Anticuerpos Antivirales/inmunología , Proliferación Celular , Femenino , Terapia Genética , Humanos , Ratones , Ratones Endogámicos C57BL , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/inmunología , Infecciones por Papillomavirus/genética , Infecciones por Papillomavirus/virología , Anticuerpos de Cadena Única/genética , Anticuerpos de Cadena Única/inmunología , Tasa de Supervivencia , Células Tumorales Cultivadas , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/virologíaRESUMEN
This report covers the case of 7 women affected by pathologies related to genital Herpesvirus and Papillomavirus. They were referred to the gynaecology outpatient clinic for colposcopic examination, and received pharmacological antiviral treatment. The patients presented clinical signs of genital Herpesvirus infections in the cervix and vulva. Cervical lesions and condylomatosis, which are characteristic of Papillomavirus infections were also detected, and patients underwent cervical cancer screening. Patients received oral and topical treatment with Acyclovir or oral treatment with Valacyclovir. During weekly or biweekly gynaecological follow-up visits, patients showed different times of remission of genital Herpesvirus. During the antiviral treatments, the vulvar and cervical Papillomavirus lesions also showed complete resolution with restitutio ad integrum of the tissues, and no recurrence at follow-up visits. Herpesvirus and Papillomavirus infections are often associated in genital infections and, as sexual transmitted infections, share the same risk factors. In the cases presented, the observed remission of HPV-related pathologies during Acyclovir and Valaciclovir treatments may suggest that antivirals are also effective in the treatment of HPV lesions. The cases described could pave the way for further investigations and clinical studies.
RESUMEN
Actinic keratosis (AK) is a carcinoma in situ precursor of cutaneous squamous cell carcinoma (cSCC), the second most common cancer affecting the Caucasian population. AK is frequently present in the sun-exposed skin of the elderly population, UV radiation being the main cause of this cancer, and other risk factors contributing to AK incidence. The dysregulation of microRNAs (miRNAs) observed in different cancers leads to an improper expression of miRNA targets involved in several cellular pathways. The TaqMan Array Human MicroRNA Card assay for miRNA expression profiling was performed in pooled AK compared to healthy skin scraping samples from the same patients. Forty-three miRNAs were modulated in the AK samples. The expression of miR-19b (p < 0.05), -31, -34a (p < 0.001), -126, -146a (p < 0.01), -193b, and -222 (p < 0.05) was validated by RT-qPCR. The MirPath tool was used for MiRNA target prediction and enriched pathways. The top DIANA-mirPath pathways regulated by the targets of the 43 miRNAs are TGF-beta signaling, Proteoglycans in cancer, Pathways in cancer, and Adherens junction (7.30 × 10-10 < p < 1.84 × 10-8). Selected genes regulating the KEGG pathways, i.e., TP53, MDM2, CDKN1A, CDK6, and CCND1, were analyzed. MiRNAs modulated in AK regulate different pathways involved in tumorigenesis, indicating miRNA regulation as a critical step in keratinocyte cancer.
RESUMEN
BACKGROUND: The ß3 human papillomavirus (HPV)49 induces immortalization of primary keratinocytes through the action of E6 and E7 oncoproteins with an efficiency similar to alpha high risk (HR)-HPV16. Since HR-HPV oncoproteins are known to alter microRNA (miRNA) expression and extracellular vesicle (EV) production, we investigated the impact of HPV49 E6 and E7 proteins on miRNA profile and EV expression, and their involvement in the control of cell proliferation. METHODS: The miRNA expression was evaluated by a miRNA array and validated by RT-qPCR in primary human keratinocytes immortalized by ß3 HPV49 (K49) or α9 HR-HPV16 (K16), and in EVs from K49 and K16. The modulation of miRNA target proteins was investigated by immunoblotting analyses. RESULTS: By comparing miRNA expression in K49 and K16 and the derived EVs, six miRNAs involved in HPV tumorigenesis were selected and validated. MiR-19a and -99a were found to be upregulated and miR-34a downregulated in both cell lines; miR-17 and -590-5p were upregulated in K49 and downmodulated in K16; miR-21 was downregulated only in K16. As for EV-carried miRNAs, the expression of miR-17, -19a, -21 and -99a was decreased and miR-34a was increased in K49 EVs. In K16 EVs, we revealed the same modulation of miR-19a, -34a, and -99a observed in producing cells, while miR-21 was upregulated. Cyclin D1, a common target of the selected miRNAs, was downmodulated in both cell lines, whereas cyclin-dependent kinase 4 was down-modulated in K49 but upregulated in K16. CONCLUSION: These data suggest that E6 and E7 proteins of ß3 HPV49 and α9 HR-HPV16 affect key factors of cell cycle control by indirect mechanisms based on miRNA modulation.
RESUMEN
BACKGROUND: Actinic keratosis (AK) is a precursor of cutaneous squamous cell carcinoma (cSCC). UV radiation is the major risk factor for AK, but certain human papillomaviruses (HPVs) of the beta genus are also involved in its development. Differently, the role of polyomaviruses (PyVs) in skin carcinogenesis is still debated. Fiftheen PyVs have been isolated from human tissues so far, including Merkel cell polyomavirus (MCPyV), the aetiological agent of Merkel cell carcinoma. METHODS: The presence of 13 PyVs was assessed in skin samples from AK patients (n = 342). Matched fresh-frozen scrapings from healthy skin (HS) and AK lesions from 242 patients, and formalin-fixed paraffin-embedded AK biopsies from a different cohort of 100 patients were analyzed by multiplex PyVs genotyping assay. RESULTS: The most frequent lesion site was the scalp in men (27.3%), and the cheek area in women (29.0%). Differences between men and women were significant for the scalp, the cheek area and the lips. Almost all the scrapings were PyV-positive (HS: 89.7%, AK: 94.6%; p = 0.04). The three most frequent PyVs were MCPyV, HPyV6 and JCPyV (HS: 87.2%, 58.7%, 6.6%, respectively; AK: 88.8%, 51.2%, 9.9%, respectively). HPyV9, TSPyV, BKPyV, HPyV7, LIPyV and SV40 were detected in < 2% of the scrapings. In most cases, matched HS and AK scrapings were both positive (MCPyV: 78.1%, HPyV6: 41.7%), or both negative for the individual genotypes (for the remaining PyVs). PyV prevalence in AK biopsies was 22.0%. Only MCPyV (21.0%) and HPyV6 (3.0%) were detected in these samples. CONCLUSIONS: PyV prevalence in HS and AK scrapings was high, but detection of PyVs exclusively in AK scrapings was rare. PyV positivity rate in AK biopsies was modest. Further research is need to reach firm conclusions regarding the role of these viruses in AK development.
RESUMEN
BACKGROUND: "High risk" human papillomavirus strains are the causative agents of the vast majority of carcinomas of the uterine cervix. In these tumors, the physical integration of the HPV genome is a frequent, though not invariable occurrence, but the constitutive expression of the E6 and E7 viral genes is always observed, suggesting key roles for the E6 and E7 oncoproteins in the process of malignant transformation. The "intracellular antibody" technology using recombinant antibodies in single-chain format offers the possibility of targeting a protein in its intracellular environment even at the level of definite domains thus representing a valuable strategy to "knock out" the function of specific proteins. METHODS: In this study, we investigate the in vitro activity of two single-chain antibody fragments directed against the "high-risk" HPV 16 E7 oncoprotein, scFv 43M2 and scFv 51. These scFvs were expressed by retroviral system in different cell compartments of the HPV16-positive SiHa cells, and cell proliferation was analyzed by Colony Formation Assay and EZ4U assay. The binding of these scFvs to E7, and their possible interference with the interaction between E7 and its main target, the tumor suppressor pRb protein, were then investigated by immunoassays, PepSet™ technology and Surface Plasmon Resonance. RESULTS: The expression of the two scFvs in the nucleus and the endoplasmic reticulum of SiHa cells resulted in the selective growth inhibition of these cells. Analysis of binding showed that both scFvs bind E7 via distinct but overlapping epitopes not corresponding to the pRb binding site. Nevertheless, the binding of scFv 43M2 to E7 was inhibited by pRb in a non-competitive manner. CONCLUSIONS: Based on the overall results, the observed inhibition of HPV-positive SiHa cells proliferation could be ascribed to an interaction between scFv and E7, involving non-pRb targets. The study paves the way for the employment of specific scFvs in immunotherapeutic approaches against the HPV-associated lesions.
Asunto(s)
Proliferación Celular , Papillomavirus Humano 16/inmunología , Proteínas E7 de Papillomavirus/inmunología , Anticuerpos de Cadena Única/inmunología , Unión Competitiva , Línea Celular Tumoral , Mapeo Epitopo , Femenino , Técnica del Anticuerpo Fluorescente , Células HEK293 , Interacciones Huésped-Patógeno , Papillomavirus Humano 16/fisiología , Humanos , Proteínas E7 de Papillomavirus/metabolismo , Unión Proteica , Proteína de Retinoblastoma/genética , Proteína de Retinoblastoma/metabolismo , Anticuerpos de Cadena Única/genética , Anticuerpos de Cadena Única/metabolismo , Resonancia por Plasmón de Superficie , Transfección , Neoplasias del Cuello Uterino/inmunología , Neoplasias del Cuello Uterino/patología , Neoplasias del Cuello Uterino/virologíaRESUMEN
BACKGROUND: The oncogenic activity of the high risk human papillomavirus type 16 (HPV16) is fully dependent on the E6 and E7 viral oncoproteins produced during viral infection. The oncoproteins interfere with cellular homeostasis by promoting proliferation, inhibiting apoptosis and blocking epithelial differentiation, driving the infected cells towards neoplastic progression. The causal relationship between expression of E6/E7 and cellular transformation allows inhibiting the oncogenic process by hindering the activity of the two oncoproteins. We previously developed and characterized some antibodies in single-chain format (scFvs) against the HPV16 E6 and E7 proteins, and demonstrated both in vitro and in vivo their antitumor activity consisting of protective efficacy against tumor progression of HPV16-positive cells. METHODS: Envisioning clinical application of the best characterized anti-HPV16 E6 and -HPV16 E7 scFvs, we verified their activity in the therapeutic setting, on already implanted tumors. Recombinant plasmids expressing the anti-HPV16 E6 scFvI7 with nuclear targeting sequence, or the anti-HPV16 E7 scFv43M2 with endoplasmic reticulum targeting sequence were delivered by injection followed by electroporation to three different preclinical models using C57/BL6 mice, and their effect on tumor growth was investigated. In the first model, the HPV16+ TC-1 Luc cells were used to implant tumors in mice, and tumor growth was measured by luciferase activity; in the second model, a fourfold number of TC-1 cells was used to obtain more aggressively growing tumors; in the third model, the HPV16+ C3 cells where used to rise tumors in mice. To highlight the scFv possible mechanism of action, H&E and caspase-3 staining of tumor section were performed. RESULTS: We showed that both the anti-HPV16 E6 and HPV16 E7 scFvs tested were efficacious in delaying tumor progression in the three experimental models and that their antitumor activity seems to rely on driving tumor cells towards the apoptotic pathway. CONCLUSION: Based on our study, two scFvs have been identified that could represent a safe and effective treatment for the therapy of HPV16-associated lesions. The mechanism underlying the scFv effectiveness appears to be leading cells towards death by apoptosis. Furthermore, the validity of electroporation, a methodology allowed for human treatment, to deliver scFvs to tumors was confirmed.
Asunto(s)
Papillomavirus Humano 16/inmunología , Proteínas Oncogénicas Virales/inmunología , Proteínas E7 de Papillomavirus/inmunología , Animales , Línea Celular Tumoral , Femenino , Humanos , RatonesRESUMEN
Human Papillomavirus 16-associated cancer, affecting primarily the uterine cervix but, increasingly, other body districts, including the head-neck area, will long be a public health problem, despite there being a vaccine. Since the virus oncogenic activity is fully ascribed to the viral E6 and E7 oncoproteins, one of the therapeutic approaches for HPV16 cancer is based on specific antibodies in single-chain format targeting the E6/E7 activity. We analyzed the Complementarity Determining Regions, repositories of antigen-binding activity, of four anti-HPV16 E6 and -HPV16 E7 scFvs, to highlight possible conformity to biophysical properties, recognized to be advantageous for therapeutic use. By epitope mapping, using E7 mutants with amino acid deletions or variations, we investigated differences among the anti-16E7 scFvs in terms of antigen-binding capacity. We also performed computational analyses to determine whether length, total net charge, surface hydrophobicity, polarity and charge distribution conformed well to those of the antibodies that had already reached clinical use, through the application of developability guidelines derived from recent literature on clinical-stage antibodies, and the Therapeutic Antibodies Profiler software. Overall, our findings show that the scFvs investigated may represent valid candidates to be developed as therapeutic molecules for clinical use, and highlight characteristics that could be improved by molecular engineering.
RESUMEN
Some human papillomavirus (HPV) genotypes are universally recognized as major etiological agents not only of ano-genital tumors but also of head and neck cancers, which show increasing incidence. The evaluation of current and future therapeutic approaches against HPV-induced tumors is a global health priority, despite an effective prophylactic vaccine against 7 of the 12 genotypes involved in the etiology of tumors being currently available. In this review, we present the main anti-HPV therapeutic approaches in clinical experimentation, with a focus on a novel tumor antigen delivery method using engineered exosomes, that we recently developed. Our system allows the induction of an efficient unrestricted cytotoxic T lymphocyte (CTL) immune response against the HPV16-E7 tumor-associated antigen, with the formation of endogenously engineered exosomes, i.e., nanovesicles spontaneously released by all cell types. Immunogenic exosomes are uploaded with HPV16-E7 due to the fusion with a unique exosome-anchoring protein referred to as Nefmut. Intramuscular injection of a DNA vector expressing the fusion protein generates exosomes sufficiently immunogenic to elicit a potent anti-16E7 CTL immune response. The approach is described here and the advantages over other existing methodologies are reported.
RESUMEN
Sequence analysis of HPV16 isolates reveals the presence of genome variants with characteristic mutations. The HPV16 variants have different geographical distribution and diverge into four phylogenetic lineages (A, B, C and D) and 16 sub-lineages: A1, A2, A3 (previously known as European variants), A4 (Asian variant), B1, B2, B3, B4, C1, C2, C3, and C4 (African variants), D1 (North-American variant), D2, D3 (Asian-American variants) and D4. Population studies showed that infections with viruses belonging to specific HPV16 sublineages confer different risks of viral persistence and cancer. In this study, 39 HPV16-positive cervical smears from European women living in Calabria (Italy) were analyzed for the presence of HPV16 variants. Cervical DNA extracts were processed by PCR to amplify L1, the Long Control Region (LCR), E6 and E7, which were sequenced. The sequences were concatenated and the 3169 nucleotides long fragments were characterized by BLAST and phylogenetic analysis. A total of 96 Single Nucleotide Polymorphism (SNPs) were detected, 29 of which mapping in the L1, 45 in the LCR, 15 in the E6 and 7 in the E7. The most common SNP was the T350G (29/39 samples, 74.4%), causing the L83â¯V amino acid change in the E6. Most of the HPV16 isolates (89.7%) had 99% of nucleotide (nt) identity to members of the A1 and A2 sublineages, while 4 isolates had 99% nt identity to members of the B2, B4, C1 and D4 sublineages. In conclusion, viruses belonging to the A1, A2, B2, B4, C1 and D4 HPV16 sublineages were found to circulate in the Calabria region.
Asunto(s)
Variación Genética , Papillomavirus Humano 16/genética , Infecciones por Papillomavirus/diagnóstico , Infecciones por Papillomavirus/virología , Vagina/virología , Frotis Vaginal , Adulto , ADN Viral , Femenino , Genotipo , Papillomavirus Humano 16/clasificación , Papillomavirus Humano 16/inmunología , Papillomavirus Humano 16/aislamiento & purificación , Humanos , Persona de Mediana Edad , Mutación , Proteínas Oncogénicas Virales/genética , Infecciones por Papillomavirus/inmunología , Polimorfismo de Nucleótido Simple , Frotis Vaginal/métodos , Adulto JovenRESUMEN
PURPOSE: Single-chain variable fragments (scFvs) are one of the smallest antigen-binding units having the invaluable advantage to be expressed by a unique short open reading frame (ORF). Despite their reduced size, spontaneous cell entry of scFvs remains inefficient, hence precluding the possibility to target intracellular antigens. Here, we describe an original strategy to deliver scFvs inside target cells through engineered extracellular vesicles (EVs). This approach relies on the properties of a Human Immunodeficiency Virus (HIV)-1 Nef mutant protein referred to as Nefmut. It is a previously characterized Nef allele lacking basically all functions of wt Nef, yet strongly accumulating in the EV lumen also when fused at its C-terminus with a foreign protein. To gain the proof-of-principle for the efficacy of the proposed strategy, the tumor-promoting Human Papilloma Virus (HPV)16-E7 protein was considered as a scFv-specific intracellular target. The oncogenic effect of HPV16-E7 relies on its binding to the tumor suppressor pRb protein leading to a dysregulated cell duplication. Interfering with this interaction means impairing the HPV16-E7-induced cell proliferation. METHODS: The Nefmut gene was fused in frame at its 3'-terminus with the ORF coding for a previously characterized anti-HPV16-E7 scFv. Interaction between the Nefmut-fused anti-HPV16-E7 scFv and the HPV16-E7 protein was tested by both confocal microscope and co-immunoprecipitation analyses on co-transfected cells. The in cis anti-proliferative effect of the Nefmut/anti-HPV16-E7 scFv was assayed by transfecting HPV16-infected cells. The anti-proliferative effect of EVs engineered with Nefmut/anti-HPV16-E7 scFv on HPV16-E7-expressing cells was evaluated in two ways: i) through challenge with purified EVs by a Real-Time Cell Analysis system and ii) in transwell co-cultures by an MTS-based assay. RESULTS: The Nefmut/anti-HPV16-E7 scFv chimeric product is efficiently uploaded in EVs, binds HPV16-E7, and inhibits the proliferation of HPV16-E7-expressing cells. Most important, challenge with cell-free EVs incorporating the Nefmut/anti-HPV16-E7 scFv led to the inhibition of proliferation of HPV16-E7-expressing cells. The proliferation of these cells was hindered also when they were co-cultured in transwells with cells producing EVs uploading Nefmut/anti-HPV16-E7 scFv. CONCLUSION: Our data represent the proof-of-concept for the possibility to target intracellular antigens through EV-mediated delivery of scFvs. This finding could be relevant to design novel methods of intracellular therapeutic interventions.
Asunto(s)
Vesículas Extracelulares/inmunología , Proteínas E7 de Papillomavirus/inmunología , Infecciones por Papillomavirus/virología , Anticuerpos de Cadena Única/administración & dosificación , Efecto Espectador , Línea Celular , Proliferación Celular , Técnicas de Cocultivo , Exosomas/inmunología , Exosomas/metabolismo , Vesículas Extracelulares/genética , Papillomavirus Humano 16/inmunología , Papillomavirus Humano 16/patogenicidad , Humanos , Proteínas E7 de Papillomavirus/metabolismo , Infecciones por Papillomavirus/prevención & control , Anticuerpos de Cadena Única/genética , Transfección , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/genéticaRESUMEN
Comprehensive multivariate models were used to disclose whether any of our previously analyzed 13 markers would be independent predictors of intermediate end point markers in cervical carcinogenesis. The expression of the following biomarkers, E-cadherin, extracellular signal-regulated kinase 1, 67-kd laminin receptor (LR67), matrix metalloproteinase 2, tissue inhibitor of metalloproteinase 2, nuclear factor-kappaB, nm23-H1, p16, proliferating cell nuclear antigen, survivin, human telomerase reverse transcriptase, topoisomerase 2alpha, and vascular endothelial growth factor (VEGF) C in 150 cervical cancer (CC) and 152 cervical intraepithelial neoplasia (CIN) lesions were determined immunohistochemically. Multivariate models were constructed to test predictive power of the markers for 3 outcomes: (1) high-grade CIN, (2) high-risk human papillomavirus (HR-HPV), and (3) CC survival. Performance indicators were calculated and compared by the areas under receiver operating characteristic (ROC) curve. Three marker panels were identified consisting of 5 independent predictors of CIN2 (E-cadherin, extracellular signal-regulated kinase 1, LR67, topoisomerase 2alpha, and VEGF-C), 3 predictors of HR-HPV (survivin, p16, and human telomerase reverse transcriptase), and 2 predictors of CC survival (nm23-H1 and tissue inhibitor of metalloproteinase 2). In predicting CIN2, the best balance between sensitivity (SE) and specificity (SP) was obtained by combining the 2 most powerful predictors in panel 1 (VEGF-C and LR67), giving the area under ROC curve, 0.897 (95% confidence interval [CI], 0.847-0.947); odds ratio, 86.27 (95% CI, 19.71-377.47); SE, 86.0%; SP, 93.3%; positive predictive value (PPV), 99.1%; and negative predictive value (NPV), 43.1%. In a hypothetical screening setting (10,000 women; CIN2 prevalence, 1%), this marker combination should theoretically detect CIN2 with 86.0% SE, 100% SP, 99.1% PPV, and 99.6% NPV, area under ROC curve of 0.930 (95% CI, 0.909-0.951), and odds ratio, 29998.0 (95% CI, 7,879.0-37,338.0). Combining 2 markers (LR67 and VEGF-C) enables accurate detection of high-grade CIN in a clinical setting. However, testing the performance of this marker combination in a screening setting necessitates their analysis in cytological samples.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Infecciones por Papillomavirus/diagnóstico , Infecciones por Papillomavirus/metabolismo , Displasia del Cuello del Útero/diagnóstico , Displasia del Cuello del Útero/metabolismo , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/metabolismo , Progresión de la Enfermedad , Femenino , Humanos , Modelos Teóricos , Análisis Multivariante , Infecciones por Papillomavirus/complicaciones , Valor Predictivo de las Pruebas , Pronóstico , Receptores de Laminina/metabolismo , Proteínas Ribosómicas , Sensibilidad y Especificidad , Neoplasias del Cuello Uterino/virología , Factor C de Crecimiento Endotelial Vascular/metabolismo , Displasia del Cuello del Útero/virologíaRESUMEN
Chlamydia trachomatis (Ct) and human papillomavirus (HPV) are the most common sexually transmitted pathogens. Whereas it is well known that infection with oncogenic HPV genotypes increases the risk of cervical cancer (CC), the implication of Ct in the pathogenesis of CC is still controversial. Hence, to investigate the possible implication of Ct infection alone, or with concomitant HPV infection, in the severity of cervical lesions, we conducted a study in 164 Caucasian HIV-negative women with abnormal Pap. Genomic HPV and Ct DNA were detected in 97 (59%) and 16 (10%) women respectively, and 15 (9%) of women were infected by both. Of the HPV positive samples, 89 (79%) were HR-HPV types or probable HR types and HPV16 was the most represented genotype. Interestingly, it was observed that co-infection was more frequent than HPV infection alone in women with high grade lesions.
Asunto(s)
Infecciones por Chlamydia/complicaciones , Chlamydia trachomatis , Coinfección , Prueba de Papanicolaou , Papillomaviridae , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/patología , Neoplasias del Cuello Uterino/complicaciones , Neoplasias del Cuello Uterino/patología , Adulto , Femenino , Humanos , Persona de Mediana Edad , Neoplasias del Cuello Uterino/virología , Adulto JovenRESUMEN
BACKGROUND: Human papillomaviruses (HPV) are the etiological agents of cervical cancer. The viral E7 protein plays a crucial role in viral oncogenesis. Many strategies have been explored to block the E7 oncoprotein activity. The single-chain variable antibody fragments (scFvs) are valuable tools in cancer immunotherapy and can be used as "intracellular antibodies" to knock out specific protein functions. For both in vivo and in vitro employment, the scFv intrinsic solubility and stability are important to achieve long-lasting effects. Here we report the characterization in terms of reactivity, solubility and thermal stability of three anti-HPV16 E7 scFvs. We have also analysed the scFv43 sequence with the aim of improving stability and then activity of the antibody, previously shown to have antiproliferative activity when expressed in HPV16-positive cells. METHODS: The three anti-HPV16 E7 scFv 32, 43 51 were selected from the ETH-2 "phage-display" library. Thermal stability was evaluated with ELISA by determining the residual activity of each purified scFv against the recombinant HPV16 E7, after incubation in the presence of human seroalbumine for different time-intervals at different temperatures. Sequence analysis of the scFvs was performed with BLAST and CLUSTALL programs. The scFv43 aminoacid changes were reverted back to the consensus sequence from the immunoglobuline database by site-directed mutagenesis. ScFv solubility was evaluated with Western blotting by determining their relative amounts in the soluble and insoluble fractions of both prokaryotic and eukaryotic systems. RESULTS: ScFv51 was the most thermally stable scFv considered. Sequence analysis of the most reactive scFv43 has evidenced 2 amino acid changes possibly involved in molecule stability, in the VH and VL CDR3 regions respectively. By mutagenesis, two novel scFv43-derived scFvs were obtained, scFv43 M1 and M2. ScFv43 M2 showed to have improved thermal stability and solubility in comparison with the parental scFv43. CONCLUSION: The characterization of 5 specific anti-HPV16 E7 scFvs shows features important for their activity in vivo. ScFv43 M2 shows higher thermal stability with respect to the parental scFv43, and scFv51 shows high stability and solubility. These properties make the 2 scFvs the best candidates to be tested for anti-E7 activity in vivo.
Asunto(s)
Anticuerpos Antivirales/inmunología , Papillomavirus Humano 16/inmunología , Fragmentos de Inmunoglobulinas/inmunología , Proteínas Oncogénicas Virales/inmunología , Anticuerpos Antivirales/química , Anticuerpos Antivirales/genética , Línea Celular Tumoral , Estabilidad de Medicamentos , Escherichia coli/genética , Femenino , Humanos , Fragmentos de Inmunoglobulinas/química , Fragmentos de Inmunoglobulinas/genética , Mutagénesis , Proteínas E7 de Papillomavirus , Biblioteca de Péptidos , SolubilidadRESUMEN
OBJECTIVE: To evaluate the 67-kd laminin receptor (67LR) in cervical cancer and its molecular links to oncogenic HPV types. STUDY DESIGN: As part of the HPV-PathogenlSS Study, a series of 150 squamous cell carcinomas (SCCs) and 152 carcinoma in situ (CIN) lesions were examined using immunohistochemical staining for LR67 and tested for HPV using polymerase chain reaction (PCR) with 3 primer sets (MY09/11, GP5+/GP6+, SPF). Followup data were available for all SCC patients, and 67 CIN lesions had been monitored with serial PCR for HPV clearance/persistence after cone treatment. RESULTS: 67LR expression increased in parallel with increasing grade of CIN (p = 0. 0001), with the most dramatic up-regulation upon the transition from CIN 2 to CIN 3 and further to SCC. This increased expression was associated with CIN 3/cancer at OR 17.04 (95% CI 7.28-39.87). The seemingly significant association of 67LR with high-risk HPV (HR-HPV) detection (OR 2.20, 95% CI 1.27-3.80) was due to confounding by the histologic grade (Mantel-Haenszel common OR = 1.118, 95% CI 0.576-2.168). Using performance indicators, 67LR expression was of little value as a marker of HR-HPV type, and it did not predict clearance/persistence of HR-HPV after treatment of CIN. Similarly, 67LR expression was not an independent prognostic factor in cervical cancer. CONCLUSION: In cervical carcinogenesis, both integrin- and nonintegrin-type LRs (67LR) probably have functions complementary to each other, mediating transient early and stable adhesions, respectively. Up-regulated 67LR expression is significantly associated with progression from CIN 2 to CIN 3 as a marker of cell proliferation. 67LR is probably orchestrated by mechanisms independent of HR-HPV oncoproteins, which seem to be more closely associated with integrin-type laminin receptors.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/patología , Infecciones por Papillomavirus/patología , Receptores de Laminina/metabolismo , Displasia del Cuello del Útero/patología , Neoplasias del Cuello Uterino/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/virología , Cuello del Útero/metabolismo , Cuello del Útero/patología , Cuello del Útero/virología , Epitelio/metabolismo , Epitelio/patología , Epitelio/virología , Matriz Extracelular/metabolismo , Femenino , Humanos , Laminina/metabolismo , Persona de Mediana Edad , Infecciones por Papillomavirus/metabolismo , Pronóstico , Regulación hacia Arriba , Neoplasias del Cuello Uterino/metabolismo , Neoplasias del Cuello Uterino/virología , Displasia del Cuello del Útero/metabolismo , Displasia del Cuello del Útero/virologíaRESUMEN
Vaccine strategies for treatment of human papillomavirus-induced cervical cancer are based on either the recombinant E7 fusion oncoprotein or E7 CTL peptides. The therapeutic potential of the E7-based vaccine depends on the use of different adjuvants. In this study, we describe for the first time the expression of the human papillomavirus 16 E7 protein in Nicotiana benthamiana plant using a potato virus X-derived vector. C57BL/6 mice immunized with E7-containing crude foliar extracts developed both humoral and cell-mediated immune responses and were protected from tumor development after challenge with the E7-expressing C3 tumoral cell line. Our data support the possibility of producing a cost-effective anticancer vaccine in plant with intrinsic adjuvant-like properties.
Asunto(s)
Vacunas contra el Cáncer/inmunología , Neoplasias Experimentales/inmunología , Neoplasias Experimentales/virología , Nicotiana/metabolismo , Proteínas Oncogénicas Virales/inmunología , Animales , Vacunas contra el Cáncer/biosíntesis , Vacunas contra el Cáncer/genética , Femenino , Hipersensibilidad Tardía/inmunología , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos C57BL , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/prevención & control , Proteínas Oncogénicas Virales/biosíntesis , Proteínas Oncogénicas Virales/genética , Proteínas E7 de Papillomavirus , Potexvirus/genética , Linfocitos T Citotóxicos/inmunología , Nicotiana/virologíaRESUMEN
Single-chain variable fragments (scFvs) expressed as "intracellular antibodies" (intrabodies) can target intracellular antigens to hamper their function efficaciously and specifically. Here we use an intrabody targeting the E6 oncoprotein of Human papillomavirus 16 (HPV16) to address the issue of a non-invasive therapy for HPV cancer patients.A scFv against the HPV16 E6 was selected by Intracellular Antibody Capture Technology and expressed as I7nuc in the nucleus of HPV16-positive SiHa, HPV-negative C33A and 293T cells. Colocalization of I7nuc and recombinant E6 was observed in different cell compartments, obtaining evidence of E6 delocalization ascribable to I7nuc. In SiHa cells, I7nuc expressed by pLNCX retroviral vector was able to partially inhibit degradation of the main E6 target p53, and induced p53 accumulation in nucleus. When analyzing in vitro activity on cell proliferation and survival, I7nuc was able to decrease growth inducing late apoptosis and necrosis of SiHa cells.Finally, I7nuc antitumor activity was demonstrated in two pre-clinical models of HPV tumors. C57BL/6 mice were injected subcutaneously with HPV16-positive TC-1 or C3 tumor cells, infected with pLNCX retroviral vector expressing or non-expressing I7nuc. All the mice injected with I7nuc-expressing cells showed a clear delay in tumor onset; 60% and 40% of mice receiving TC-1 and C3 cells, respectively, remained tumor-free for 17 weeks of follow-up, whereas 100% of the controls were tumor-bearing 20 days post-inoculum. Our data support the therapeutic potential of E6-targeted I7nuc against HPV tumors.