In the absence of infection, the pathophysiology of endotracheal tube-induced sore throat pain is unclear. Activated neutrophils release elastase, reactive oxygen species, and inflammatory cytokines known to contribute to neuropathic pain. Sterile tissue injury can cause the release of damage-associated molecular patterns such as mitochondrial DNA that promote neutrophil activation. We hypothesized that endotracheal tube-induced sore throat pain is linked to mitochondrial DNA-mediated neutrophil inflammation. A nonrandomized prospective survey for sore throat pain was conducted in 31 patients who required short-term intubation and had no evidence of upper airway infection. Patterns of neutrophil abundance, activation, and mitochondrial DNA levels were analyzed in tracheal lavage fluid following intubation and prior to extubation. Thirteen of 31 patients reported sore throat pain. Sore throat patients had high neutrophilia with elevated adhesion molecule and TLR9 expression and constitutive reactive oxygen species generation. Tracheal lavage fluid from sore throat patients accumulated mitochondrial DNA and stimulated neutrophils to release mediators associated with pain in a TLR9- and DNAse-dependent fashion. Endotracheal tube-induced sore throat is linked to the release of mitochondrial DNA and can drive TLR9-mediated inflammatory responses by neutrophils reported to cause pain. Mitigating the effects of cell-free mitochondrial DNA may prove beneficial for the prevention of endotracheal tube-mediated sore throat pain.

Abstract Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that mediate a number of physiological and pathological processes, such as matrix degradation, tissue remodeling, inflammation and tumor metastasis. The objective of this study was to develop and characterize a vaccine targeting stromal antigens expressed by cancer associated fibroblasts (CAFs). We focused on MMP11 (or stromelysin 3, ST3), that has been detected primarily in CAFs and its expression correlates with aggressive clinical behavior and invasiveness of different types of carcinoma. We demonstrated that intramuscular injection of genetic vectors such as Adenovirus (Ad) and plasmid DNA encoding MMP11 engineered variants followed by in vivo electroporation (DNA-EP) resulted in breakage of immune tolerance and induction of both cell mediated and humoral immune response. Importantly, MMP11 vaccine was able to confer significant antitumoral protection in a chemically induced, MMP11 overexpressing colon cancer model both in prophylactic and therapeutic settings. To determine the mechanism of action of MMP11 vaccine, we have utilized IFNgamma- and μmicroMT-knock out mice, devoid of T- and B-cell immune response, respectively. Our results show that both arms of the immune response are important to confer the therapeutic effect. Moreover, MMP11 stromal vaccine showed synergic effects when combined with genetic vaccines targeting classic tumor associated antigens, such as telomerase reverse transcriptase (TERT) and carcinoembryonic antigen (CEA). Finally, to assess the immunogenicity and the safety of MMP11 vaccine in a large animal model, nonhuman primates have been vaccinated with Ad and DNA-EP. A strong immune response was measured with no detectable side effects. In addition, MMP11 detection and spontaneous immune responses in the blood of breast and prostate cancer patients further corroborate MMP11 as a valid target for immune intervention. Taken together, these data support the use of MMP11 as a potential candidate for cancer immunotherapy in human clinical trials. Citation Format: Laura Luberto, Rita Mancini, Arianna Di Napoli, Daniela Peruzzi, Federica Mori, Giuseppe Roscilli, Emanuele Marra, Manuela Cappelletti, Gennaro Ciliberto, Luigi Aurisicchio. Targeting the stroma to hit the tumor: MMP11 as a novel target for cancer immunotherapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 291. doi:10.1158/1538-7445.AM2015-291

Several cancer vaccine efforts have been directed to simultaneously cotarget multiple tumor antigens, with the intent to achieve broader immune responses and more effective control of cancer growth. Genetic cancer vaccines based on in vivo muscle electro-gene-transfer of plasmid DNA (DNA-EGT) and adenoviral vectors represent promising modalities to elicit powerful immune responses against tumor-associated antigens (TAAs) such as carcinoembryonic antigen (CEA) and human epidermal growth factor receptor-2 (HER2)/neu. Combinations of these modalities of immunization (heterologous prime-boost) can induce superior immune reactions as compared with single-modality vaccines. We have generated a dual component-dual target genetic cancer vaccine consisting of a DNA moiety containing equal amounts of two plasmids, one encoding the extracellular and transmembrane domains of HER2 (ECD.TM) and the other encoding CEA fused to the B subunit of Escherichia coli heat-labile toxin (LTB), and of an adenoviral subtype 6 dicistronic vector carrying the same two tumor antigens gene constructs. The CEA/HER2 vaccine was tested in two different CEA/HER2 double-transgenic mouse models and in NOD/scid-DR1 mice engrafted with the human immune system. The immune response was measured by enzyme-linked immunospot assay, flow cytometry, and ELISA. The CEA/HER2 vaccine was able to break immune tolerance against both antigens. Induction of a T cell and antibody immune response was detected in immune-tolerant mice. Most importantly, the vaccine was able to slow the growth of HER2/neu⁺ and CEA⁺ tumors. A significant T cell response was measured in NOD/scid-DR1 mice engrafted with human cord blood cells. In conclusion, the CEA/HER2 genetic vaccine was immunogenic and able to confer significant therapeutic effects. These data warrant the evaluation of this vaccination strategy in human clinical trials.

Background: We have previously reported endotracheal intubation induces upper airway injury that leads to neutrophil recruitment in the absence of any evidence of infection. Neutrophil Extracellular Traps (NETs) are thought to play role in containing infection but it remains unclear if tissue injury stimulate NETs. Here we ask if endotracheal intubation can induce trachea-infiltrating neutrophils to produce NETs. Methods: Lavage above the tracheal cuff and peripheral blood was obtained from 3 healthy surgical patients that have undergone endotracheal intubation for general anesthesia. At the end of surgery tracheal lavage and peripheral blood neutrophils were cultured for 3 hrs with or without 25nM phorbol 12-myristate 13-acetate (PMA). NET formation was analyzed by fluorescence microscopy using antibodies specific for the NET components neutrophils elastase and histone protein H2b along with the DNA stain Hoescht 33342. Results: Both peripheral blood and tracheal lavage neutrophils produced NETs in response to PMA (Figure 1.A) However, unlike neutrophils in the peripheral blood tracheal lavage neutrophils spontaneously produced NETs in culture (Figure 1.B). Conclusions: Human infiltrating tracheal neutrophils in response to endotracheal intubation produce NETs. These data suggest that mechanically induced tissue injury is sufficient to promote NET formation.

Client-owned pet dogs represent exceptional translational models for advancement of cancer research because they reflect the complex heterogeneity observed in human cancer. We have recently shown that a genetic vaccine targeting dog telomerase reverse transcriptase (dTERT) and based on adenovirus DNA electro-gene-transfer (Ad/DNA-EGT) technology can induce strong cell-mediated immune responses against this tumor antigen and increase overall survival of dogs affected by B-cell lymphosarcoma (LSA) in comparison with historical controls when combined with a cyclophosphamide, vincristine, and prednisone (COP) chemotherapy regimen. Here, we have conducted a double-arm clinical trial with an extended number of LSA patients, measured the antigen-specific immune response, and evaluated potential toxic effects of the immunotherapy along with a follow-up of patients survival for 3.5 years. The immune response was measured by enzyme-linked immunospot assay. The expression of dTERT was quantified by quantitative polymerase chain reaction. Changes in hematological parameters, local/systemic toxicity or organic dysfunction and fever were monitored over time during the treatment. dTERT-specific cell-mediated immune responses were induced in almost all treated animals. No adverse effects were observed in any dog patient that underwent treatment. The overall survival time of vaccine/COP-treated dogs was significantly increased over the COP-only cohort (>76.1 vs. 29.3 weeks, respectively, p<0.0001). There was a significant association between dTERT expression levels in LSA cells and overall survival among vaccinated patients. In conclusion, Ad/DNA-EGT-based cancer vaccine against dTERT in combination with COP chemotherapy is safe and significantly prolongs the survival of LSA canine patients. These data confirm the therapeutic efficacy of dTERT vaccine and support the evaluation of this approach for other cancer types as well as the translation of this approach to human clinical trials.

Functional T-cell epitope discovery is a key process for the development of novel immunotherapies, particularly for cancer immunology. In silico epitope prediction is a common strategy to try to achieve this objective. However, this approach suffers from a significant rate of false-negative results and epitope ranking lists that often are not validated by practical experience. A high-throughput platform for the identification and prioritization of potential T-cell epitopes is the iTopiaTM Epitope Discovery SystemTM, which allows measuring binding and stability of selected peptides to MHC Class I molecules. So far, the value of iTopia combined with in silico epitope prediction has not been investigated systematically. In this study, we have developed a novel in silico selection strategy based on three criteria: (1) predicted binding to one out of five common MHC Class I alleles; (2) uniqueness to the antigen of interest; and (3) increased likelihood of natural processing. We predicted in silico and characterized by iTopia 225 candidate T-cell epitopes and fixed-anchor analogs from three human tumor-associated antigens: CEA, HER2 and TERT. HLA-A2-restricted fragments were further screened for their ability to induce cell-mediated responses in HLA-A2 transgenic mice. The iTopia binding assay was only marginally informative while the stability assay proved to be a valuable experimental screening method complementary to in silico prediction. Thirteen novel T-cell epitopes and analogs were characterized and additional potential epitopes identified, providing the basis for novel anticancer immunotherapies. In conclusion, we show that combination of in silico prediction and an iTopia-based assay may be an accurate and efficient method for MHC Class I epitope discovery among tumor-associated antigens.

Purpose: Fetal lung adenocarcinoma (FLAC) is an extremely rare subtype of pulmonary adenocarcinoma estimated to be the 0.5% of all lung cancers. Therefore a standardized model of FLAC primary cell culture and evidence-based treatment guidelines are not available. The aim of this study is to characterize FLAC primary cell culture, to evaluate the biological features of this uncommon tumor and the in vitro drug response. Methods: FLAC specimen was obtained from a 59-years-old female patient, cultured in vitro with DMEM-F12 medium supplemented with 5% FBS and maintained in culture for more than 6 passages. Primary cells from a lung adenocarcinoma specimen were as well cultured and used as control for all the in vitro experiments. Immunohistochemistry for β-catenin, TTF-1, Ki67, cKit, MDM2, p53, S-100, EGFR, E-cadherin, cytokeratin 7 and 8/18 was performed on paraffin-fixed specimen. Immunofluorescence on cells in culture was assessed for MDM2, p53, CD133. Specimen and cells in culture were analyzed by real time PCR for oncogenic mutations (KRAS, EGFR) and for a stem cells gene panel. In vitro tumorigenicity was tested by plating efficency and soft agar colony formation assays. Cell proliferation was determined and a cell viability test was performed after treatment of FLAC cells with tyrosine kinase inhibitors (erlotinib and gefitinib), temozolomide (TMZ), cisplatin, gemcitabine and cysplatin+gemcitabine by MTS assay. Results: A primary cell culture of human FLAC was characterized and standardized. FLAC histotype was confirmed by immunohistochemistry. Immunofluorescence showed a positivity for MDM2, but not for p53 and CD133. By molecular analysis, DNA from both specimen and cells in culture was found to harbor epidermal growth factor receptor (EGFR) kinase domain non-sense mutation in exon 20 and no mutations in the K-ras gene. Primary FLAC cells showed a colony formation activity and the soft agar assay revealed an anchorage-indipendent growth. At 48 hours FLAC cells proliferation was inhibited of 56% and 41% by erlotinib and gefitinib respectively, with an IC50 value of 10 μM, compared with the control proliferation (lung adenocarcinoma cells) inhibited of 25% and 60% by erlotinib and gefitinib respectively (p=0,17; p=0,005). However, FLAC cell viability at 48 hours after being treated with cisplatin 10 μM was 3%, compared with the control viability that was 16% (p=0,007). Conclusion: This well-characterized FLAC primary cell culture provide a unique model for future studies in lung cancer biology and drug response. Although chemosensitivity to cisplatin was determined, erlotinib and gefitinib were effective against FLAC cells and appear to represent a novel targeting approach for the treatment of this rare tumor.

The telomerase reverse transcriptase (TERT) is an attractive target for cancer vaccination because its expression is reactivated in most tumors. In this study, we have evaluated the ability of a genetic vaccine targeting murine TERT (mTERT) based on DNA electroporation (DNA-EP) and adenovirus serotype 6 (Ad6) to exert therapeutic effects in combination with a novel TLR9 agonist, referred to as immune modulatory oligonucleotide (IMO), as an adjuvant. IMO was administered to mice at the same time as vaccine. IMO induced dose-dependent cytokine secretion and activation of NK cells. Most importantly, vaccination of mice with IMO in combination with mTERT vaccine conferred therapeutic benefit in tumor bearing animals and this effect was associated with increased NK, DC and T cell tumor infiltration. These data show that appropriate combination of a DNA-EP/Ad6-based cancer vaccine against TERT with IMO induces multiple effects on innate and adaptive immune responses resulting in a significant antitumor efficacy.

Canine cancers occur with an incidence similar to that of humans and share many features with human malignancies including histological appearance, tumor genetics, biological behavior, and response to conventional therapies. As observed in humans, the telomerase reverse transcriptase (TERT) activity is largely confined to tumor tissues and absent in the majority of normal dog tissues. Therefore, dog TERT (dTERT) can constitute a valid target for translational cancer immunotherapy. We have evaluated the ability of adenovirus serotype 6 (Ad6) and DNA electroporation (DNA-EP) to induce immune responses against dTERT in dogs affected by malignant lymphoma (ML). The vaccine was combined with standard chemotherapy regimen [cyclophosphamide, vincristine, prednisone (COP)]. dTERT-specific immune response was induced in 13 out of 14 treated animals (93%) and remained detectable and long-lasting with the absence of autoimmunity or other side effects. Most interestingly, the survival time of vaccine/Chemo-treated dogs was significantly increased over historic controls of Chemo-treated animals (>97.8 versus 37 weeks, respectively, P = 0.001). Our results show that Ad6/DNA-EP-based cancer vaccine against dTERT overcomes host immune tolerance, should be combined with chemotherapy, induces long-lasting immune responses, and significantly prolongs the survival of ML canine patients. These data support further evaluation of this approach in human clinical trials.

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The human telomerase reverse transcriptase (hTERT) is an attractive target for human cancer vaccination because its expression is reactivated in most human tumors. We have evaluated the ability of DNA electroporation (DNA-EP) and adenovirus serotype 6 (Ad6) to induce immune responses against hTERT in non-human primates (NHPs) (Macaca mulatta). Vaccination was effective in all treated animals, and the adaptive immune response remained detectable and long lasting without side effects. To further enhance the efficacy of the hTERT vaccine, we evaluated the combination of hTERT vaccine and a novel TLR9 agonist, referred to as immunomodulatory oligonucleotide (IMO). Monkeys were dosed weekly with IMO concurrently with the vaccine regimen and showed increases in cytokine secretion and activation of natural killer (NK) cells compared with the group that received vaccine alone. Using a peptide array, a specific profile of B-cell reactive epitopes was identified when hTERT vaccine was combined with IMO. The combination of IMO with hTERT genetic vaccine did not impact vaccine-induced TERT-specific cell-mediated immunity. Our results show that appropriate combination of a DNA-EP/Ad6-based cancer vaccine against hTERT with IMO induces multiple effects on innate and adaptive immune responses in NHPs.

The use of adenovirus (Ad) as vaccine vectors is hindered by pre-existing immunity to human Ads in most of the human population. In order to overcome this limitation, uncommon alternative Ad serotypes need to be utilized. In this study, an E1-E3 deleted recombinant Ad based on the chimpanzee serotype 3 (ChAd3) was engineered to express human carcinoembryonic antigen (CEA) protein or rat neu extracellular/transmembrane domains (ECD.TM). ChAd3 vectors were tested in CEA transgenic (CEA.Tg) and BALB/NeuT mice, which show immunologic tolerance to these antigens. ChAd3 is capable of inducing an immune response comparable to that of hAd5 serotype-based vectors, thus breaking tolerance to tumor associated antigens (TAAs) and achieving anti-tumor effects. Of importance is that ChAd3 can overcome hAd5 pre-existing immunity and work in conjunction with DNA electroporation (DNA-EP) and other Ad vaccines based on common human serotypes.

Purpose: Matrix metalloproteinases (MMP) are zinc-dependent endopeptidases that mediate numerous physiologic and pathologic processes, including matrix degradation, tissue remodeling, inflammation, and tumor metastasis. To develop a vaccine targeting stromal antigens expressed by cancer-associated fibroblasts, we focused on MMP11 (or stromelysin 3). MMP11 expression correlates with aggressive profile and invasiveness of different types of carcinoma.Experimental Design: To show the efficacy of a vaccine targeting MMP11, we constructed a series of plasmid DNA vectors expressing murine MMP11. Mice were vaccinated by i.m. injection followed by in vivo DNA electroporation. A chemically induced, MMP11-overexpressing colon cancer model was established and characterized. Antibody and T-cell responses were determined, and immunoreactive epitopes were characterized. To analyze the possible use of MMP11 as tumor-associated antigen in cancer patients, HLA-A2.1 transgenic mice (HHD) were used to identify reactive epitopes as tools to assess immunogenicity in humans.Results: Using microarray, we confirmed the overexpression of MMP11 mRNA in a large panel of human tumor samples. MMP11 vaccine induced cell mediated and antibody immune response and exerted significant antitumoral protection in mice with colon cancer in prophylactic and therapeutic settings. HHD transgenic mice were vaccinated with a plasmid encoding human MMP11, and a HLA-A2.1 - restricted epitope (hMMP(237)) was identified. hMMP(237) was shown to be immunogenic in human peripheral blood mononuclear cells (PBMC) by in vitro priming.Conclusion: Our study describes the identification of MMP11 as a novel broadly expressed tumor associated antigen as target candidate for cancer immunotherapy.

Adenovirus (Ad)-based gene transfer has been successfully utilised in gene therapy and vaccine applications. To date, an increasing number of human clinical trials utilise recombinant Ad-based vectors as a gene transfer platform. In particular, progress has been made recently in utilising Ad-based vectors as a vaccine platform in HIV, cancer immunotherapy approaches and in vaccination for other infections. Despite these successes, the scientific and bio-industrial communities have recently recognised that innate and pre-existing immunity against Ad vectors can constitute a serious obstacle to the development and application of this technology. It is essential to overcome vector-mediated immune responses, such as production of inflammatory cytokines and pre-existing immunity to Ad, because the induction of these responses not only shortens the period of gene expression but also leads to serious side effects. This review focuses on the biology of Ad infection and the approaches that are being adopted to overcome immunity against the Ad-based vectors.

Human leukocyte antigen (HLA)-A2.1 transgenic mice (HHD) represent a valuable model to study and predict the immunogenicity of vaccines against pathogens. However, HHD mice are unsuitable for in vivo studies of cancer vaccines against human tumor-associated antigens because they lack T-cell tolerance that is key to define the potency of the treatment. In this study, we developed HHD/carcinoembryonic antigen P(CEA) hybrid mice by breeding transgenic mice homozygous for CEA with HHD. These mice express human CEA, present epitopes solely through HLA-A2.1 molecules and constitute a unique in vivo animal model to study HLA-A2.1-restricted immune response of a human CEA-based vaccine. Owing to the immune tolerance, HHD/CEA mice show a limited immune response and expansion of a different and restricted T-cell receptor repertoire after antigen-specific stimulation. Our data show that genetic vectors expressing CEA and peptide-based vaccines are able to efficiently break immune tolerance against CEA and to elicit strong immune response against HLA-A2.1-restricted CEA epitopes. Most importantly, efficient lysis of human CEA+/HLA-A2.1+ tumor cells was observed and significant protection against HHD/CEA tumor cells was achieved in HHD/CEA-vaccinated mice. Hence, HHD/CEA provides a relevant model for the evaluation of the potential efficacy of human CEA-based vaccines.

PURPOSE:Oligodeoxynucleotides containing unmethylated CpG dinucleotides induce innate and adaptive immunity through Toll-like receptor 9 (TLR9). In the present study, we have examined the ability of a novel agonist of TLR9, called immunomodulatory oligonucleotide (IMO), to enhance effects of a HER-2/neu plasmid DNA electroporation/adenovirus (DNA-EP/Ad) vaccine.EXPERIMENTAL DESIGN:BALB/NeuT mice were treated with DNA-EP vaccine alone, IMO alone, or the combination of two agents starting at week 13, when all mice showed mammary neoplasia. Tumor growth and survival were documented. Antibody and CD8+ T-cell responses were determined. Peptide microarray analysis of sera was carried out to identify immunoreactive epitopes. Additionally, microCT and microPET imaging was carried out in an advanced-stage tumor model starting treatment at week 17 in BALB/NeuT mice.RESULTS:The combination of DNA-EP and IMO resulted in significant tumor regression or delay to tumor progression. 2-Deoxy-2-[18F]fluoro-D-glucose microPET and microCT imaging of mice showed reduced tumor size in the DNA-EP/IMO combination treatment group. Mice treated with the combination produced greater antibody titers with IgG2a isotype switch and antibody-dependent cellular cytotoxicity activity than did mice treated with DNA-EP vaccine. An immunogenic B-cell linear epitope, r70, within the HER-2 dimerization domain was identified through microarray analysis. Heterologous DNA-EP/Ad vaccination combined with IMO increased mice survival.CONCLUSION:The combination of HER-2/neu genetic vaccine and novel agonist of TLR9 had potent antitumor activity associated with antibody isotype switch and antibody-dependent cellular cytotoxicity activities. These results support possible clinical trials of the combination of DNA-EP/Ad-based cancer vaccines and IMO.

The chapter will focus on the tools available for performing a selective replacement of a hydrogen by a metal in organic substrates. In addition some applications to the synthesis of valuable building blocks or target compounds using simple and selective strategies with alkali metals will be also presented.