Immunotherapy in new pre-clinical models of HPV-associated oral cancers

Paolini, Francesca; Massa, Silvia; Manni, Isabella; Franconi, Rosella; Venuti, Aldo

doi:10.4161/hv.23232

Cited by 30 publications

(37 citation statements)

References 35 publications

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“…This difference may affect the expression level of the HPV proteins which, in turn, may influence specific therapies targeting the viral oncoproteins . However, Q‐RT PCR for E7‐containing transcripts did not show any significant difference between TC‐1 and C3 cells …”

Section: Discussionmentioning

confidence: 93%

“…22 However, Q-RT PCR for E7-containing transcripts did not show any significant difference between TC-1 and C3 cells. 23 In both the TC-1 and C3 preclinical models formerly used, tumor cell challenge in C57BL/6 mice was typically utilized to evaluate a therapeutic intervention in terms of both safety and induction of HPV-specific immune responses able to eradicate a transplanted tumor. In contrast, in our study, such models were employed to assess, in environmental conditions more appropriate than in vitro cultures, an antitumor activity not based on the immunological response of the host but rather due to a specific binder (M2SD) that blocks a protein involved in tumor development.…”

Section: Discussionmentioning

confidence: 99%

“…This occurrence does not seem to be correlated to the different levels of E7 expression, which are comparable in the two cell lines even though slightly lower in TC-1 cells. 23 The efficacy difference may be ascribed to a diverse biological behavior of these cell lines, which were obtained by different transfection procedures and have different origin, namely embryonic for C3 and epithelial for TC-1 cells.…”

Section: Discussionmentioning

confidence: 99%

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In vivo antitumor effect of an intracellular single‐chain antibody fragment against the E7 oncoprotein of human papillomavirus 16

Accardi

Paolini

Mandarino

et al. 2013

Intl Journal of Cancer

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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.Human papillomaviruses (HPVs) belonging to 15 genotypes defined as "high risk," are the recognized cause of an increasing number of malignancies among which cervical cancer (CC) is the most represented in women worldwide.1,2 Despite the high protective efficacy of the HPV vaccine, expected to reduce the number of HPV-associated cancers in the coming decades, non-invasive therapies are urgently needed for avoiding overtreatment of pre-tumor lesions and preventing or treating metastatic lesions in the case of established tumors, particularly for the treatment of immunosuppressed people. 3The E6 and E7 oncoproteins of the high risk genotypes are tumor-specific antigens expressed in tumors and precursor lesions; they contribute to viral immunoevasion and act in concert to promote tumor development through the interaction with multiple cellular proteins. The E7 mainly affects factors involved in proliferation and cell cycle regulation, such as the retinoblastoma (pRb) and the whole pocket proteins family, the p21 and p27 cyclin-dependent kinase inhibitors, and the cyclins A and E, whereas the E6 binds to the p53 tumor suppressor through the E6-AP and to Bak proteins to ensure hampering of cell apoptosis.4,5 Therefore, E6 and E7 represent ideal targets for antitumor therapeutic interventions. Several approaches were and are currently explored to counteract the oncoproteins at gene or protein level. 6 In the last decades, emerged the possibility of designing drugs based on antibodies again...

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Section: Discussionmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

In vivo antitumor effect of an intracellular single‐chain antibody fragment against the E7 oncoprotein of human papillomavirus 16

Accardi

Paolini

Mandarino

et al. 2013

Intl Journal of Cancer

Self Cite

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“…Because inducible oral-specific tumor models imply labor-intensive processes, 16,17 we chose to develop orthotopic tumor models using cell lines. Few orthotopic models have been described using syngeneic murine cell line derived from oral cancer [18][19][20] or using TC-1 cells. 9,21 Although we tested the injection of cells in the basis of the tongue as described, 9 considering the risk of early death and the difficulty of monitoring IL tumor in mice, 22 we decided to inject TC-1-Luc cells into the mucosa of the CH, as published by others.…”

Section: Discussionmentioning

confidence: 99%

Intra-cheek immunization as a novel vaccination route for therapeutic vaccines of head and neck squamous cell carcinomas using plasmo virus-like particles

et al. 2016

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Despite current therapy, head and neck squamous cell carcinomas (HNSCCs) arising from various mucosal sites of the upper aero-digestive tract frequently relapse in a loco-regional manner and have a poor prognosis. Our objective was to validate an innovative mucosal route of vaccination using plasmo viruslike particles (pVLPs) in a pre-clinical orthotopic model of HNSCCs. For this purpose, we used pVLP-E7, that are plasmid DNA encoding retroviral virus-like particles carrying a truncated E7 oncoprotein from HPV-16 as antigen model, to vaccinate mice bearing pre-established TC-1 tumors implanted into the buccal mucosa. pVLP-E7 were combined with clinical grade TLR agonists (Imiquimod and CpG-ODN). In this preclinical orthotopic model, whose tumor microenvironment resembles to those of human HNSCCs, different mucosal vaccination routes were tested for their ability to elicit efficient immune and antitumoral responses. Results showed that mucosal intra-cheek (IC) vaccinations using pVLP-E7, comparatively to intradermic vaccinations (ID), gave rise to higher mobilization of mucosal (CD49a C) CD8 C specific effector T cells in both tumor draining lymph nodes (TdLNs) and tumor microenvironment resulting in better antitumor effects and in a long-term protection against tumor rechallenge. In vivo CD8 C depletion demonstrated that antitumoral effects were fully dependent upon the presence of CD8 C T cells. Validation of IC mucosal vaccinations with pVLPs combined with adjuvants using a pre-clinical orthotopic model of HNSCC provides valuable pre-clinical data to rapidly envision the use of such therapeutic vaccines in patients with HNSCCs, inasmuch as vaccinal components and adjuvants can be easily obtained as clinical grade reagents.

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“…Thus, a therapeutic vaccine, targeting already infected individuals, is also required. Several therapeutic HPVspecific E7-based vaccine formulations have been tested in animal models [12] and some have advanced into clinical trials [13,14]. HPV16 E7 is 98 amino acids long with a M r 11,000 based on amino acid composition and an apparent electrophoretic M r of 16,000-19,000 [15].…”

Section: Introductionmentioning

confidence: 99%

Translational Fusion and Redirection to Thylakoid Lumen as Strategies to Enhance Accumulation of Human Papillomavirus E7 Antigen in Tobacco Chloroplasts

et al. 2014

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Human papillomavirus (HPV) is the causal agent of cervical cancer, one of the most common causes of death in women worldwide, and its E7 antigen is the major candidate for a therapeutic vaccine. The large scale production of E7 by molecular farming that would lead to the development of a safe and inexpensive vaccine is impaired by its low accumulation level in the plant cell. To enhance antigen production in the plastids, two alternative strategies were carried out: the expression of E7 as a translational fusion to β-glucuronidase enzyme and redirection of E7 into the thylakoid lumen. The use of the β-glucuronidase as a partner protein turned out to be a successful strategy, antigen expression levels were enhanced between 30 and 40 times relative to unfused E7. Moreover, best accumulation, albeit at a high metabolic cost that compromised biomass production, was obtained redirecting E7 into the thylakoid lumen by the incorporation of the N-terminal transit peptide, Str. Following this approach lumenal E7 production exceeded the stromal by two orders of magnitude. Our results highlight the relevance of exploring different strategies to improve recombinant protein stability for certain transgenes in order to exploit potential advantages of recombinant protein accumulation in chloroplasts.

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Immunotherapy in new pre-clinical models of HPV-associated oral cancers

Cited by 30 publications

References 35 publications

In vivo antitumor effect of an intracellular single‐chain antibody fragment against the E7 oncoprotein of human papillomavirus 16

In vivo antitumor effect of an intracellular single‐chain antibody fragment against the E7 oncoprotein of human papillomavirus 16

Intra-cheek immunization as a novel vaccination route for therapeutic vaccines of head and neck squamous cell carcinomas using plasmo virus-like particles

Translational Fusion and Redirection to Thylakoid Lumen as Strategies to Enhance Accumulation of Human Papillomavirus E7 Antigen in Tobacco Chloroplasts

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