Hotspots of microplastic accumulation at the land-sea transition and their spatial heterogeneity: The Po River prodelta (Adriatic Sea)

Deltas are the locus of river-borne sediment accumulation, however, their role in sequestering plastic pollutants is still overlooked. By combining geomorphological, sedimentological, and geochemical analyses, which include time-lapse multibeam bathymetry, sediment provenance, and μFT-IR analyses, we investigate the fate of plastic particles after a river flood event providing an unprecedented documentation of the spatial distribution of sediment as well as of microplastics (MPs), including particles fibers, and phthalates (PAEs) abundances in the subaqueous delta. Overall sediments are characterized by an average of 139.7 ± 80 MPs/kg d.w., but display spatial heterogeneity of sediment and MPs accumulation: MPs are absent within the active sandy delta lobe, reflecting dilution by clastic sediment (ca. 1.3 Mm3) and sediment bypass. The highest MP concentration (625 MPs/kg d.w.) occurs in the distal reaches of the active lobe where flow energy dissipates. In addition to MPs, cellulosic fibers are relevant (of up to 3800 fibers/kg d.w.) in all the analyzed sediment samples, and dominate (94 %) with respect to synthetic polymers. Statistically significant differences in the relative concentration of fiber fragments ≤0.5 mm in size were highlighted between the active delta lobe and the migrating bedforms in the prodelta. Fibers were found to slightly follow a power law size distribution coherent with a one-dimensional fragmentation model and thus indicating the absence of a size dependent selection mechanism during burial. Multivariate statistical analysis suggests traveling distance and bottom-transport regime as the most relevant factors controlling particle distribution. Our findings suggest that subaqueous prodelta should be considered hot spots for the accumulation of MPs and associated pollutants, albeit the strong lateral heterogeneity in their abundances reflects changes in the relative influence of fluvial and marine processes.

Identification and characterization of heteroclitic peptides in TCR-binding positions with improved HLA-binding efficacy

The antigenicity as well as the immunogenicity of tumor associated antigens (TAAs) may need to be potentiated in order to break the immunological tolerance. To this aim, heteroclitic peptides were designed introducing specific substitutions in the residue at position 4 (p4) binding to TCR. The effect of such modifications also on the affinity to the major histocompatibility class I (MHC-I) molecule was assessed. The Trp2 antigen, specific for the mouse melanoma B16F10 cells, as well as the HPV-E7 antigen, specific for the TC1 tumor cell lines, were used as models. Affinity of such heteroclitic peptides to HLA was predicted by bioinformatics tools and the most promising ones were validated by structural conformational and HLA binding analyses. Overall, we demonstrated that TAAs modified at the TCR-binding p4 residue are predicted to have higher affinity to MHC-I molecules. Experimental evaluation confirms the stronger binding, suggesting that this strategy may be very effective for designing new vaccines with improved antigenic efficacy.

Immunotherapy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is considered an immunogenic tumor that arises in chronically inflamed livers due to underlying chronic liver disease caused by viral and non-viral pathogenesis. This inflammation leads to tumor development and is associated to higher tumor immunogenicity. For this reason immunotherapeutic approaches may be suitable therapeutic strategies for HCC. Indeed, several preclinical and clinical data support this hypothesis showing that immunotherapy and even more their combination may be a good alternative candidate for the treatment of HCC patients. However, considering that the liver plays a central role in host defense as well as in the maintenance of self-tolerance, it is characterized by a strong intrinsic immune suppressive microenvironment as well as by a high immune evasion, which may represent a major impediment for an effective immune response against tumor. Furthermore, the low expression of tumor antigens on liver cancer cells leads to a lower T-cell activation and tumor infiltration, resulting in a less efficient control of the tumor growth and, consequently, in a worse clinical outcome. For this reason, strategies should be developed to counteract the different factors in the HCC tumor microenvironment playing a major role in reducing the effects of immunotherapy.

Tackling hepatocellular carcinoma with individual or combinatorial immunotherapy approaches

Hepatocellular carcinoma (HCC) is the third leading cause of death from cancer globally. Indeed, there is a single drug approved as first-line systemic therapy in advanced unresectable HCC, providing a very limited survival benefit. In earlier stages, 5-year survival rates after surgical and loco-regional therapies are extremely variable depending on the stage of disease. Nevertheless, HCC is considered an immunogenic tumor arising in chronically inflamed livers. In such a scenario, immunotherapy strategies for HCC, in particular combinations including cancer vaccines, may represent a key therapeutic tool to improve clinical outcome in HCC patients. However, a lot of improvement is needed given the disappointing results obtained so far.

High Somatic Mutation and Neoantigen Burden Do Not Correlate with Decreased Progression-Free Survival in HCC Patients not Undergoing Immunotherapy

Cancer genome instability leads to accumulation of mutations which may result into tumor-specific mutated “neoantigens”, not be affected by central T-cell tolerance. Such neoantigens are considered the optimal target for the patient’s anti-tumor T cell immunity as well as for personalized cancer immunotherapy strategies. However, only a minor fraction of predicted neoantigens are relevant to the clinical outcome. In the present study, a prediction algorithm was applied using datasets of RNA sequencing from all 377 Hepatocellular carcinoma (HCC) patients available at The Cancer Genome Atlas (TCGA), to predict neoantigens to be presented by each patient’s autologous HLA molecules. Correlation with patients’ survival was performed on the 115 samples for whom the exact date of death was known. A total of 30 samples were used for the training set, and 85 samples were used for the validation sets. Neither the somatic mutations nor the number nor the quality of the predicted neoantigens correlate as single parameter with survival of HCC patients who do not undergo immunotherapy treatment. Furthermore, the preferential presentation of such neoantigens in the context of one of the major histocompatibility complex MHC class I molecules does not have an impact on the survival. On the contrary, the expression of Granzyme A (GZMA) is significantly correlated with survival and, in the context of high GZMA, a direct correlation between number and quality of neoantigens with survival is observed. This is in striking contrast to results described in cancer patients undergoing immunotherapy, in which a strong correlation between Tumor Mutational Burden (TMB), number of predicted neoantigens and survival has been reported.

Abstract 1198: Neoantigen load, tumor immune infiltration and prediction of survival in HCC patients

Predicted neoantigens can be relevant to the clinical outcome only when their affinity to MHC I molecule is significantly higher than the corresponding wild type peptide, and when they do not show any homology to unrelated self antigens (e.g. true predicted neoantigens - TPNAs). In addition, they may show homology to pathogen-derived antigens, representing a “super” neoantigen if the patient is immunologically primed. A novel algorithm for prediction of TPNAs presented by each patient's autologous HLA molecules was applied to datasets of all 377 HCC patients available at The Cancer Genome Atlas (TCGA). The number of neoantigens was highly variable between different HCC patients with an average of 14.5 per sample. However, considering those with the highest predicted antigenic quality, the average of neoantigens per samples with such parameters dropped down to 1.5. Results showed that patients’ survival did not correlate with the quantity nor the quality of neoantigens. However, only when the cytotoxic activity of tumor infiltrating lymphocytes was low, a correlation between neoantigens and survival was observed, suggesting that in this setting a higher number of neoantigens is required for a more pronounced efficacy on the patients’ survival. Predicted neoantigens with homology to unrelated self antigens or pathogen-derived antigens were identified. Nevertheless, a single neoantigen per patient with such a homology did not influence patients’ survival. The same algorithm was applied to a cohort of hepatocellular carcinoma (HCC) patients enrolled at our Institute, confirming the results obtained on the TCGA cohort. Interestingly, TPNAs with highest homology to pathogen’s antigens were found in the only HCC long-term survival patient. A pre-existing T cell immunity specific for these TPNAs was revealed in the patient, possibly explaining the favourable clinical outcome. In conclusion, the new algorithm allowed the identification of the very few TPNAs in HCC samples. The relevance of quantity and quality of neoantigens in the evolution of HCC without treatment with checkpoint inhibitors (CI) appears to be less central, unless the tumor cytotoxic lymphocyte infiltration is low. The identification in a single patient, of a primed immunity against a neoantigen homologous to a pathogen-derived antigen, can possibly explain the long term survival. Therefore, the identification of high quality neoantigens remains a priority for developing personalized active immunotherapies also in the HCC model characterized by a low mutational burden.

Note: This abstract was not presented at the meeting.

Citation Format: Maria Tagliamonte, Angela Mauriello, Roberta Zeuli, Annacarmen Petrizzo, Maria Lina Tornesello, Michele Ceccarelli, Franco M. Buonaguro, Luigi Buonaguro. Neoantigen load, tumor immune infiltration and prediction of survival in HCC patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1198.

Unique true predicted neoantigens (TPNAs) correlates with anti-tumor immune control in HCC patients

Background

A novel prediction algorithm is needed for the identification of effective tumor associated mutated neoantigens. Only those with no homology to self wild type antigens are true predicted neoantigens (TPNAs) and can elicit an antitumor T cell response, not attenuated by central tolerance. To this aim, the mutational landscape was evaluated in HCV-associated hepatocellular carcinoma.

Methods

Liver tumor biopsies and adjacent non-tumor liver tissues were obtained from 9 HCV-chronically infected subjects and subjected to RNA-Seq analysis. Mutant peptides were derived from single nucleotide variations and TPNAs were predicted using two prediction servers (e.g. NetTepi and NetMHCstabpan) by comparison with corresponding wild-type sequences, non-related self and pathogen-related antigens. Immunological confirmation was obtained in preclinical as well as clinical setting.

Results

The development of such an improved algorithm resulted in a handful of TPNAs despite the large number of predicted neoantigens. Furthermore, TPNAs may share homology to pathogen’s antigens and be targeted by a pre-existing T cell immunity. Cross-reactivity between such antigens was confirmed in an experimental pre-clinical setting. Finally, TPNAs homologous to pathogen’s antigens were found in the only HCC long-term survival patient, suggesting a correlation between the pre-existing T cell immunity specific for these TPNAs and the favourable clinical outcome.

Conclusions

The new algorithm allowed the identification of the very few TPNAs in cancer cells, and those targeted by a pre-existing immunity strongly correlated with long-term survival. Only such TPNAs represent the optimal candidates for immunotherapy strategies.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1662-9) contains supplementary material, which is available to authorized users.

Potentiating cancer vaccine efficacy in liver cancer

Hepatocellular carcinoma (HCC) is the most common liver malignancy with a poor prognosis and an overall 5-year survival rate of approximately 5-6%. This is due because standard of care treatment options are limited and none of them shows a sufficient efficacy. HCC is an "inflammation-induced cancer" and preliminary preclinical and clinical data suggest that immunotherapeutic approaches may be a good alternative candidate for the treatment of HCC patients improving the dismal prognosis associated with this cancer. However, recent findings strongly suggest that an optimal immunotherapy in HCC requires the combination of an immune activator with immune modulators, aiming at compensating the strong liver immune suppressive microenvironment. One of the most promising strategy could be represented by the combination of a cancer vaccine with immunomodulatory drugs, such as chemotherapy and checkpoint inhibitors. Very limited examples of such combinatorial strategies have been evaluated in HCC to date, because HCC easily develops resistance to standard chemotherapy, which is also poorly tolerated by patients with liver cirrhosis. The present review describes the most update knowledge in this field.

Evaluation of the perception of clinical competencies by nursing students in the different clinical settings: an observational study

INTRODUCTION

The university educational sphere has many dilemmas. The question of sufficient knowledge and skills for students to acquire abilities to provide care in different clinical setting is one important dilemma.

AIM

To measure the level of competencies by nursing students and its application in different clinical environments.

METHODS

Nursing students of two Italian universities participated in the research. Data collection took place April to July 2015 using the Nurse Competence Scale. The Strengthening Reporting of Observational Studies in Epidemiology Guidelines was used to describe the study. Pearson's chi-square test, Student's t test, and regression tests were used for statistical analysis.

RESULTS

The questionnaire response rate was 87.27% (n = 698). Most of the nursing students assessed their level of competency as 'good' and evaluated themselves as more competent than their actual nursing role. Students also appraised themselves as competent either via their clinical practices accomplished or in the therapeutic interventions.

CONCLUSION

This study shows that the self-evaluation of the competencies acquired by nursing students in clinical settings in Latium and Abruzzo is of a good standard. This study also affirms that NCS is a valuable and reliable tool to measure clinical competencies in different clinical settings.

Cellular prognostic markers in hepatitis-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and accounts for about 6% of all new cancers diagnosed worldwide. Moreover, it is the third and the fifth leading cause of death from cancer in men and women, respectively. HBV and HCV chronic infection is the main risk factor for HCC.

A range of therapies are used in the management of HCC according to the extent and severity of liver disease. In this perspective, evaluation of prognosis represents a crucial step for proper management of HCC patients. However, the clinical outcome can be significantly different in HCC patients within the same stage of disease. Therefore, many efforts have been made to define new parameters with more precise prognostic value, and the search for HCC prognostic markers is gaining momentum. The present review aims at providing an update on cellular prognostic markers for HCC.

Inhibition of tumor growth by cancer vaccine combined with metronomic chemotherapy and anti-PD-1 in a pre-clinical setting

Tumor microenvironment (TME) is characterized by multiple immune suppressive mechanisms able to suppress anti-tumor effector cell immunity. Combinatorial strategies, including vaccine and immunomodulatory drugs, need to be developed for improved immunotherapy efficacy.

A novel combinatorial approach was assessed in C57BL/6 mice injected with mouse melanoma B16F10 cells. A multi-peptide vaccine (PEPT) was combined with a low dose metronomic chemotherapy (MCT) and an anti-PD-1 checkpoint inhibitor (CI). Statistical analysis were performed with the unpaired two-sided Student’s t-test and ANOVA.

Animals treated with the multi-peptide vaccine combined with MCT or CI showed remarkable delay in tumor growth and prolonged survival as compared to control groups. The multi-pronged combination including PEPT+MCT+CI was able to prolong survival in all mice and inhibit tumor growth in 66.6% of mice. All animals which did not show tumor growth were re-challenged with the same melanoma cells and one of them showed complete tumor growth inhibition. The anti-tumor effect was associated with strong T cell immune response to vaccine mutated peptides and significant reduction of regulatory T cells.

The combination of a vaccine with MCT and CI was highly efficient in potentiating the vaccine’s anti-tumor effects. The approach is highly promising to be moved into clinical trial.

Immunological effects of a novel RNA-based adjuvant in liver cancer patients

Evaluation of biological effects of adjuvants on immune cells has been assessed in a limited number of studies. Moreover, no data are available on samples derived from cancer patients who may have a severe immune impairment. The effects of a novel RNA-based adjuvant (RNAdjuvant® developed by CureVac) were assessed in an ex vivo setting on PBMCs obtained from 8 healthy volunteers and 17 HCC patients, using a multiparametric approach to analyze network dynamics of early immune responses. Evaluation of CD80, CD86 and HLA-DR expression, cytokine production as well as gene expression was performed. Moreover, the downstream effect on CD4+ T cell phenotyping was evaluated. Treatment with RNAdjuvant® showed comparable effects on PBMCs of both HCC and healthy subjects. In particular, CD80, CD86 and HLA-DR expression was found up-regulated in circulating dendritic cells, which promoted a CD4+ T cell differentiation toward an effector phenotype. A mixed Th1/Th2 cytokine pattern was induced, although a more predominant production of TNFα and IFNγ was observed in HCC patients versus healthy controls. The cytokine profile was further confirmed by gene transcriptional analysis, which showed up-regulation of several genes involved in innate and adaptive immune-related pathways. The present study is the first demonstration that HCC patients and healthy subjects are equally responsive to an adjuvant. This may suggest that the same vaccine formulation including the RNAdjuvant® might have similar potency in healthy subjects and cancer patients.

Application of the Immunoscore as prognostic tool for hepatocellular carcinoma

To date, the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC) tumor, nodes, metastasis (TNM) classification represents the standard system for evaluation of prognosis in solid tumors. However, the clinical outcome can be significantly different in patients with the same TNM stage. Therefore, many efforts have been made aiming to define new prognostic parameters.

Indeed, analyses conducted in large cohorts of colorectal cancer patients emphasized the prognostic value of tumor-infiltrating lymphocytes, leading to the development of a prognostic score referred to as “Immunoscore”.

In this commentary, we recapitulate the study by Gabrielson and colleagues, recently published in Cancer Immunology Research, addressing the role of intratumoral CD3⁺ and CD8⁺ T cells as well as as prognostic markers for hepatocellular carcinoma.

The authors demonstrate that Immunoscore represents a valuable prognostic marker in patients with hepatocellular carcinoma who have undergone primary tumor resection, supporting its application in a tumor setting other than colorectal cancer.

Abstract A045: Inhibition of tumor growth by combination of metronomic chemotherapy and checkpoint inhibitor with a cancer vaccine

The efficacy of cancer immunotherapies can be significantly limited by the immune suppressive soluble factors and cell types characterizing the tumor microenvironment. Strategies combining anti-immune suppressive therapies and cancer vaccines need to be evaluated. In the present study, a novel combinatorial strategy was assessed in a mouse model using an aggressive therapeutic setting based on sub-cutaneous ectopic implantation of B16 melanoma cells. The anti-immune suppressive therapy included a novel mix of chemotherapy agents, administered in a metronomic fashion (MCT), and an anti-PD-1 checkpoint inhibitor (CI). The vaccine (VAC) was a multi-peptide cocktail, including melanoma-specific tumor-associated antigens. The newly designed strategy was shown to be safe, well tolerated and highly effective. Animals treated with MCT or CI showed a remarkable delay in tumor growth and prolonged survival as compared to control group. Such effect was significantly enhanced by the combination with the multi-peptide vaccine. In particular, the multi-pronged MCT+CI+VAC combination resulted in a remarkable inhibition of tumor growth in 5/6 animals. The anti-tumor effect was associated with a strong T cell immune response to vaccine peptides as well as significant intra-tumor T cell infiltration associated with reduction in Tregs. Overall, the results showed that the combination of anti-immune suppressive therapy and vaccine was able to strongly potentiate the anti-tumor effects. The described approach is highly promising to significantly enhance the anti-tumor effects induced by a therapeutic cancer vaccine.

Citation Format: Maria Tagliamonte, Annacarmen Petrizzo, Angela Mauriello, Antonio Luciano, Domenica Rea, Antonio Barbieri, Claudio Arra, Piera Maiolino, Maria Lina Tornesello, Gennaro Ciliberto, Franco M. Buonaguro, Luigi Buonaguro. Inhibition of tumor growth by combination of metronomic chemotherapy and checkpoint inhibitor with a cancer vaccine [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A045.

Abstract A046: Identification and validation of HCC-specific gene transcriptional signature for tumor antigen discovery

A novel two-step bioinformatics strategy was applied for identification of signatures with therapeutic implications in hepatitis-associated HCC. Transcriptional profiles from HBV- and HCV-associated HCC samples were compared with normal liver tissue controls. Resulting HCC modulated genes were subsequently compared with different normal tissue samples. Two related signatures were identified, namely “HCC-associated” and “HCC-specific.” Expression data were validated by RNA-Seq analysis carried out on unrelated HCC samples and protein expression was confirmed according to the publicly available database at http://www.proteinatlas.org/. Among all, only two proteins (namely AKR1B10 and IGF2BP3) were found strictly HCC-specific with no expression in 18/20 normal tissues. Target peptides for vaccine design were predicted for both proteins associated with the most prevalent HLA-class I and II alleles. The described novel strategy showed to be feasible for identification of HCC-specific proteins as highly potential target for HCC immunotherapy (Petrizzo et al., Scientific Reports, in press).

Citation Format: Annacarmen Petrizzo, Francesca P. Caruso, Maria Tagliamonte, Maria Lina Tornesello, Michele Ceccarelli, Valerio Costa, Marianna Aprile, Roberta Esposito, Gennaro Ciliberto, Franco M. Buonaguro, Luigi Buonaguro. Identification and validation of HCC-specific gene transcriptional signature for tumor antigen discovery [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A046.

Abstract 742: A novel multidrug metronomic chemotherapy significantly delays tumor growth in mice

The tumor immunosuppressive microenvironment represents a major obstacle to an effective tumor-specific cellular immune response.

We have previously shown that a novel multi-drug chemotherapy administered in a metronomic fashion was able to increase immune response to peptides. The chemotherapy consisted of a cocktail including taxanes (paclitaxel and docetaxel) and alkylating (cyclophosphamide) agents. The newly designed strategy was shown to be safe, well tolerated and significantly efficacious (Tagliamonte et al., CII 2015).

In the present study, the effect on the immunosuppressive tumor microenvironment by the same multi-drug cocktail was evaluated in a mouse model upon sub-cutaneous ectopic implantation of B16 melanoma cells.

Treated animals showed a remarkable delay in tumor growth and prolonged survival as compared to control group. Such an effect was directly correlated with CD4+ T cell reduction and CD8+ T cell increase. A significant reduction in the percentage of both CD25+FoxP3+ and CD25+CD127low regulatory T cell population was found in the spleens as well as in the tumor lesions. An intrinsic CD8+ T cell response specific to B16 naturally expressed Trp2 TAA was observed. The same metronomic chemotherapy combined to a vaccine based on mutated antigens, was subsequently shown to increase immune response to vaccine resulting in a significant delay of B16 tumor growth as well as animal survival.

The novel multi-drug daily metronomic chemotherapy evaluated in the present study was very effective in counterbalancing the immunosuppressive tumor microenvironment and enhancing vaccine efficacy. Consequently, the intrinsic as well as vaccine-induced anti-tumor T cell immunity could exert its function containing tumor growth.

Overall, the described metronomic chemotherapy may represent a promising adjuvant approach to enhance anti-tumor cellular immunity and amplify the biological effects of therapeutic cancer vaccines.

Citation Format: Maria Tagliamonte, Annacarmen Petrizzo, Maria Lina Tornesello, Antonio Luciano, Domenica Rea, Antonio Barbieri, Claudio Arra, Maria Napolitano, Gennaro Ciliberto, Franco M. Buonaguro, Luigi Buonaguro. A novel multidrug metronomic chemotherapy significantly delays tumor growth in mice. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 742.

Cellular prognostic markers in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the five big killers worldwide and is frequently associated with chronic hepatitis B and C virus (HBV and HCV) infections. Tumor microenvironment consists of a complex network of cells and factors that plays a key role in the tumor progression and prognosis. This is true also for HCC. Several studies have shown strikingly strong correlation between HCC clinical prognosis and intratumoral infiltration of cells affecting tumor growth, invasion, angiogenesis and metastasis. None of such cells is yet validated for routine diagnostic and prognostic assessment. The present review aims at providing a state-of-the-art of such studies.

A novel multi-drug metronomic chemotherapy significantly delays tumor growth in mice

BACKGROUND

The tumor immunosuppressive microenvironment represents a major obstacle to an effective tumor-specific cellular immune response.

METHODS

In the present study, the counterbalance effect of a novel metronomic chemotherapy protocol on such an immunosuppressive microenvironment was evaluated in a mouse model upon sub-cutaneous ectopic implantation of B16 melanoma cells. The chemotherapy consisted of a novel multi-drug cocktail including taxanes and alkylating agents, administered in a daily metronomic fashion. The newly designed strategy was shown to be safe, well tolerated and significantly efficacious.

RESULTS

Treated animals showed a remarkable delay in tumor growth and prolonged survival as compared to control group. Such an effect was directly correlated with CD4(+) T cell reduction and CD8(+) T cell increase. Furthermore, a significant reduction in the percentage of both CD25(+)FoxP3(+) and CD25(+)CD127(low) regulatory T cell population was found both in the spleens and in the tumor lesions. Finally, the metronomic chemotherapy induced an intrinsic CD8(+) T cell response specific to B16 naturally expressed Trp2 TAA.

CONCLUSION

The novel multi-drug daily metronomic chemotherapy evaluated in the present study was very effective in counterbalancing the immunosuppressive tumor microenvironment. Consequently, the intrinsic anti-tumor T cell immunity could exert its function, targeting specific TAA and significantly containing tumor growth. Overall, the results show that this represents a promising adjuvant approach to significantly enhance efficacy of intrinsic or vaccine-elicited tumor-specific cellular immunity.

Combinatorial immunotherapy strategies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common liver malignancy. The prognosis for HCC patients greatly varies according to the stage at diagnosis. Overall it is poor, with a 5-year survival rate of approximately 5-6%. Immunotherapeutic interventions represent a novel and effective therapeutic tool. However, only few immunotherapy trials for HCC have been conducted so far with contrasting results, suggesting that significant improvements are needed. Indeed, the liver is characterized by a strong intrinsic immune suppressive microenvironment which needs to be counterbalanced with immune stimulatory approaches. Therefore, the implementation of combinatorial protocols combining immune stimulatory strategies with specific immunotherapy approaches could result in a dramatic improvement of efficacy and clinical outcome in HCC patients. The present review aims at describing the state of the art in immunotherapy strategies for HCC and future perspectives.

Abstract B130: Evaluation of novel metronomic chemotherapy and cancer vaccine combinatorial strategy

The efficacy of cancer immunotherapy approaches can be significantly hampered by the tumor immune suppressive microenvironment. In the present study, a novel combinatorial strategy (i.e. metronomic chemotherapy plus vaccine) is evaluated in a mouse model in an aggressive therapeutic setting based on sub-cutaneous ectopic implantation of B16 melanoma cells. The chemotherapy is a multi-drug cocktail including taxanes and alkylating agents, administered in a daily metronomic fashion. The vaccine is a multi-peptide cocktail of universal tumor antigen hTERT epitopes adjuvanted in Montanide.

Immunizations have been performed comparing a standard sub-cutaneous delivery with a laser-assisted epidermal immunogen delivery by P.L.E.A.S.E.™ Professional (Pantec Biosolutions). The latter, indeed, creates evenly distributed micropores through to the epidermis and provides a great opportunity to efficiently deliver vaccine antigens to Langerhans cells (LC) in the epidermis.

An interim analysis shows that the immunogenicity as well as the therapeutic effect on tumor growth of the vaccine is significantly increased by the combination with metronomic chemotherapy, and the laser-assisted epidermal immunogen delivery appears to be a very effective strategy as vaccine delivery. Complete description of both immunogenicity and therapeutic effects on tumor growth will be described.

Citation Format: Maria Tagliamonte, Annacarmen Petrizzo, Maria Lina Tornesello, Antonio Luciano, Domenica Rea, Antonio Barbieri, Claudio Arra, Maria Napolitano, Gennaro Ciliberto, Luigi Aurisicchio, Claudio Coscia, Tobias Baechle, Franco M. Buonaguro, Luigi Buonaguro. Evaluation of novel metronomic chemotherapy and cancer vaccine combinatorial strategy. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B130.

Antigen-specific vaccines for cancer treatment

Vaccines targeting pathogens are generally effective and protective because based on foreign non-self antigens which are extremely potent in eliciting an immune response. On the contrary, efficacy of therapeutic cancer vaccines is still disappointing. One of the major reasons for such poor outcome, among others, is the difficulty of identifying tumor-specific target antigens which should be unique to the tumors or, at least, overexpressed on the tumors as compared to normal cells. Indeed, this is the only option to overcome the peripheral immune tolerance and elicit a non toxic immune response. New and more potent strategies are now available to identify specific tumor-associated antigens for development of cancer vaccine approaches aiming at eliciting targeted anti-tumor cellular responses. In the last years this aspect has been addressed and many therapeutic vaccination strategies based on either whole tumor cells or specific antigens have been and are being currently evaluated in clinical trials. This review summarizes the current state of cancer vaccines, mainly focusing on antigen-specific approaches.

Novel metronomic chemotherapy and cancer vaccine combinatorial strategy for hepatocellular carcinoma in a mouse model

Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer and represents the third and the fifth leading cause of cancer-related death worldwide in men and women, respectively. Hepatitis B virus (HBV) and hepatitis C virus (HCV) chronic infections account for pathogenesis of more than 80 % of primary HCC. HCC prognosis greatly varies according to stage at beginning of treatment, but the overall 5-year survival rate is approximately 5-6 %. Given the limited number of effective therapeutic strategies available, immunotherapies and therapeutic cancer vaccines may help in improving the clinical outcome for HCC patients. However, the few clinical trials conducted to date have shown contrasting results, indicating the need for improvements. In the present study, a novel combinatorial strategy, based on metronomic chemotherapy plus vaccine, is evaluated in a mouse model. The chemotherapy is a multi-drug cocktail including taxanes and alkylating agents, which is administered in a metronomic-like fashion. The vaccine is a multi-peptide cocktail including HCV as well as universal tumor antigen TERT epitopes. The combinatorial strategy designed and evaluated in the present study induces an enhanced specific T cell response, when compared to vaccine alone, which correlates to a reduced Treg frequency. Such results are highly promising and may pave way to relevant improvements in immunotherapeutic strategies for HCC and beyond.

Systems Biology Approach for Cancer Vaccine Development and Evaluation

Therapeutic cancer vaccines do not hold promise yet as an effective anti-cancer treatment. Lack of efficacy or poor clinical outcomes are due to several antigenic and immunological aspects that need to be addressed in order to reverse such trends and significantly improve cancer vaccines’ efficacy. The newly developed high throughput technologies and computational tools are instrumental to this aim allowing the identification of more specific antigens and the comprehensive analysis of the innate and adaptive immunities. Here, we review the potentiality of systems biology in providing novel insights in the mechanisms of the action of vaccines to improve their design and effectiveness.

Systems vaccinology for cancer vaccine development

Results of therapeutic vaccines for established chronic infections or cancers are still unsatisfactory. The only therapeutic cancer vaccine approved for clinical use is the sipuleucel-T, for the treatment of metastatic prostate cancer, which induces a limited 4-month improvement in the overall survival of vaccinated patients compared to controls. This represents a remarkable advancement in the cancer immunotherapy field, although the clinical outcome of cancer vaccines needs to be substantially improved. To this aim, a multipronged strategy is required, including the evaluation of mechanisms underlying the effective elicitation of immune responses by cancer vaccines. The recent development of new technologies and computational tools allows the comprehensive and quantitative analysis of the interactions between all of the components of innate and adaptive immunity over time. Here we review the potentiality of systems biology in providing novel insights in the mechanisms of action of vaccines to improve their design and effectiveness.

Prediction of individual immune responsiveness to a candidate vaccine by a systems vaccinology approach

Background

We have previously shown that a candidate idiotype vaccine, based on the IGKV3-20 light chain protein, is able to induce activation of circulating antigen presenting cells (APCs) in both HCV-positive and HCV-negative subjects, with production of Th2-type cytokines. In addition, such a candidate idiotype vaccine induces an early gene expression pattern, characterized by the strong induction of an innate immune response, and a late pattern, characterized by a prevalent B cell response. Nonetheless, some HCV-positive individuals showed a complete lack of maturation of circulating APCs with low levels of cytokine production, strongly suggesting the possible identification of selective impairments in immune response in individual subjects.

Method

Peripheral blood mononuclear cells (PBMCs) were stimulated ex vivo with IGKV3-20 for 24 h and 6 days. Analysis of the global gene expression profile as well as the cytokine pattern was performed for individual subjects.

Results

The gene expression profile showed a strong agreement with the cytokine pattern. Indeed, the expression pattern of immune-related genes is highly predictive of the individual immunological phenotype.

Conclusion

The overall results represent a proof of concept, indicating the efficacy of such an ex vivo screening platform for predicting individual’s responsiveness to an antigen as well as guiding optimization of vaccine design. Larger cohort study will be needed to validate results observed in the study.

Challenges in cancer vaccine development for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common liver malignancy, representing the third and fifth leading cause of death from cancer worldwide in men and women, respectively. The main risk factor for the development of HCC is the hepatitis B and C virus (HBV and HCV) infection; non-viral causes (e.g., alcoholism and aflatoxin) are additional risk factors. HCC prognosis is generally poor because of the low effectiveness of available treatments and the overall 5-year survival rate is approximately 5-6%. In this framework, immunotherapeutic interventions, including cancer vaccines, may represent a novel and effective therapeutic tool. However, only few immunotherapy trials for HCC have been conducted so far with contrasting results, suggesting that improvements in several aspects of the immunotherapy approaches need to be implemented. In particular, identification of novel specific tumor antigens and evaluation of most advanced combinatorial strategies could result in unprecedented clinical outcomes with great beneficial effect for HCC patients. The state of the art in immunotherapy strategies for HCC and future perspectives are reported in the present review.

Pattern of activation of human antigen presenting cells by genotype GII.4 norovirus virus-like particles

Background

Virus-like particles (VLPs) from an Italian GII.4 norovirus strain were used to investigate activation and maturation of circulating antigen presenting cells (APCs) of human origin.

Methods

Peripheral blood mononuclear cells (PBMCs) isolated from five healthy subjects were pulsed ex vivo with VLPs, and stained with a set of monoclonal antibodies (MAbs) for phenotypic analysis by flow cytometry. Cytokine release in cell supernatants was investigated by ELISA.

Results

Norovirus VLPs induced activation and maturation of circulating APCs derived from the five donors, as well as production of IL-6, IFN-γ and TNF-α cytokines.

Conclusions

The present results suggest that VLPs can activate antigen presenting cells for an efficient induction of the adaptive immune response.

Immunogenomics approaches for vaccine evaluation

Vaccines represent a potent tool to prevent or contain diseases with high morbidity or mortality. However, despite their widespread use, there is still a limited understanding of the mechanisms underlying the effective elicitation of protective immune responses by vaccines. The integrated co-operation between cells and molecules of innate and adaptive immune systems is under intense study by several groups and constantly updated. The recent development of new technologies and computational tools permits the comprehensive and quantitative analysis of the interactions between all of the components of immunity over time. This study reviews recent progress in exploiting an immunogenomics approach, within the systems biology strategy, to study and evaluate vaccine strategies for infectious and neoplastic diseases. The final goal of this approach is 2-fold, looking for novel and unpredictable mechanisms as well as identifying common immune signatures, relevant for predicting immune responsiveness to improve the design of vaccine strategies. Such approach, indeed, would enable the switch from 'empirical' to 'knowledge-based' vaccinology, leading to a patient-tailored treatment.

Multiparametric analyses of human PBMCs loaded ex vivo with a candidate idiotype vaccine for HCV-related lymphoproliferative disorders

Hepatitis C virus (HCV) has been identified as one of the major risk factors for type II mixed cryoglobulinemia (MC), during the clinical evolution of chronic hepatitis, which may lead to development of B cell non-Hodgkin's lymphoma (NHL). We have previously shown that the candidate idiotype vaccine, based on the IGKV3-20 light chain protein, is able to induce activation and maturation of circulating antigen presenting cells (APCs) in both HCV-positive and HCV-negative healthy control subjects, with production of Th2-type cytokines. Here, the effect of the recombinant IGKV3-20 protein on human peripheral blood mononuclear cells (PBMCs) from HCV-positive subjects, with known blood levels of cryoglobulins, is shown via gene expression profiling analysis combined to multiparameter flow cytometry and multiplex analyses of cytokines.

Innate immunity and hepatitis C virus infection: a microarray's view

Hepatitis C virus (HCV) induces a chronic infection in more than two-thirds of HCV infected subjects. The inefficient innate and adaptive immune responses have been shown to play a major pathogenetic role in the development and persistence of HCV chronic infection. Several aspects of the interactions between the virus and the host immune system have been clarified and, in particular, mechanisms have been identified which underlie the ability of HCV to seize and subvert innate as well as adaptive immune responses. The present review summarizes recent findings on the interaction between HCV infection and innate immune response whose final effect is the downstream inefficient development of antigen-specific adaptive immunity, thereby contributing to virus persistence.

Dendritic cells in the pathogenesis and treatment of human diseases: a Janus Bifrons?

Dendritic cells (DCs) represent the bridging cell compartment between a variety of nonself antigens (i.e., microbial, cancer and vaccine antigens) and adaptive immunity, orchestrating the quality and potency of downstream immune responses. Because of the central role of DCs in the generation and regulation of immunity, the modulation of DC function in order to shape immune responses is gaining momentum. In this respect, recent advances in understanding DC biology, as well as the required molecular signals for induction of T-cell immunity, have spurred many experimental strategies to use DCs for therapeutic immunological approaches for infections and cancer. However, when DCs lose control over such 'protective' responses - by alterations in their number, phenotype and/or function - undesired effects leading to allergy and autoimmune clinical manifestations may occur. Novel therapeutic approaches have been designed and currently evaluated in order to address DCs and silence these immunopathological processes. In this article we present recent concepts of DC biology and some medical implications in view of therapeutic opportunities.

Immune signatures in human PBMCs of idiotypic vaccine for HCV-related lymphoproliferative disorders

Hepatitis C virus (HCV) is one of the major risk factors for chronic hepatitis, which may progress to cirrhosis and hepatocellular carcinoma, as well as for type II mixed cryoglobulinemia (MC), which may further evolve into an overt B-cell non-Hodgkin's lymphoma (NHL).

It has been previously shown that B-cell receptor (BCR) repertoire, expressed by clonal B-cells involved in type II MC as well as in HCV-associated NHL, is constrained to a limited number of variable heavy (VH)- and light (VL)-chain genes. Among these, the VK3-20 light chain idiotype has been selected as a possible target for passive as well as active immunization strategy.

In the present study, we describe the results of a multiparametric analysis of the innate and early adaptive immune response after ex vivo stimulation of human immune cells with the VK3-20 protein. This objective has been pursued by implementing high-throughput technologies such as multiparameter flow cytometry and multiplex analysis of cytokines and chemokines.

Molecular and phylogenetic analysis of HIV-1 variants circulating in Italy

Objective

The continuous identification of HIV-1 non-B subtypes and recombinant forms in Italy indicates the need of constant molecular epidemiology survey of genetic forms circulating and transmitted in the resident population.

Methods

The distribution of HIV-1 subtypes has been evaluated in 25 seropositive individuals residing in Italy, most of whom were infected through a sexual route during the 1995–2005 period. Each sample has been characterized by detailed molecular and phylogenetic analyses.

Results

18 of the 25 samples were positive at HIV-1 PCR amplification. Three samples showed a nucleotide divergence compatible with a non-B subtype classification. The phylogenetic analysis, performed on both HIV-1 env and gag regions, confirms the molecular sub-typing prediction, given that 1 sample falls into the C subtype and 2 into the G subtype. The B subtype isolates show high levels of intra-subtype nucleotide divergence, compatible with a long-lasting epidemic and a progressive HIV-1 molecular diversification.

Conclusion

The Italian HIV-1 epidemic is still mostly attributable to the B subtype, regardless the transmission route, which shows an increasing nucleotide heterogeneity. Heterosexual transmission and the interracial blending, however, are slowly introducing novel HIV-1 subtypes. Therefore, a molecular monitoring is needed to follow the constant evolution of the HIV-1 epidemic.

[Assessment of left internal thoracic artery anastomosis with left anterior descending coronary artery by Doppler echocardiography]

PURPOSE

To study the value of Doppler echocardiography as a tool for the evaluation of left internal thoracic artery graft (LITAG) patency in patients who underwent coronary revascularization using minimally invasive bypass surgery without extracorporeal circulation.

METHODS

The first 12 consecutive patients were studied after coronary artery bypass surgery using a 5 MHz Doppler transducer. Doppler signals for the systolic and diastolic flow velocities were preferably obtained in the second intercostal space. All patients underwent coronary angiography while hospitalized.

RESULTS

The exam was feasible in 93% of patients. Doppler flow pattern was predominantly diastolic (pattern A) in patients with patent anastomoses (6/7). In patients with occluded anastomoses (4/4) Doppler flow pattern was predominantly systolic (pattern B) (p = 0.003).

CONCLUSION

Internal thoracic artery flow pattern as measured by Doppler echocardiography after minimally invasive coronary artery bypass graft surgery is an accurate method for identifying LITAG patency.

[Myocardial revascularization through small left anterior minithoracotomy]

PURPOSE

To analyze the results of myocardial revascularization through small left anterior thoracotomy utilizing the left thoracic internal artery (LTIA) to left anterior descending coronary artery (LAD) without cardiopulmonary bypass, in order to simplify the operative procedure.

METHODS

From September/95 till August/96 we operated on 45 patients with lesions in LAD or LAD and diagonal arteries that were revascularized with an anastomoses of the LTIA to LAD or LAD and diagonal as composite grafts, through left anterior small thoracotomy. In the second postoperative day 43 out of 45 patients were restudied with arteriography and/or transthoracic echocardiography that showed excellent patency in 39 of them.

RESULTS

Six patients with obstruction or stenoses were reoperated through median sternotomy without complications. We did not observe flow through intercostal arteries in these restudies except in cases of obstructed anastomosis, showing that it is not necessary to ligate these branches. We observed too, excellent correlation between angiographic patterns and diastolic flows detected in the thoracic internal artery with transthoracic echocardiography.

CONCLUSION

These initial results suggest that this approach may be good to a subset of patients with lesions in LAD and/or diagonal arteries and if associated with complementary angioplasties of other coronary arteries may be the best choice of invasive treatment of coronary insufficiency in a near future.

Randomized trial of direct coronary angioplasty versus intravenous streptokinase in acute myocardial infarction

OBJECTIVES

The objective of this study was to obtain preliminary data on the relative clinical utility of direct coronary angioplasty compared with that of intravenous thrombolytic therapy for patients with acute myocardial infarction.

BACKGROUND

The relative merits of intravenous thrombolytic therapy and direct coronary angioplasty as treatment for acute myocardial infarction are incompletely understood, and randomized trials of these treatments have been extremely limited.

METHODS

One hundred patients with ST segment elevation presenting to a single high volume interventional center within 6 h of the onset of chest pain were randomized to receive either streptokinase (1.2 million U intravenously over 1 h) or immediate catheterization and direct coronary angioplasty. Patients were excluded for age > or = 75 years, prior bypass surgery, Q wave infarction in the region of ischemia or excessive risk of bleeding. All patients were then treated with aspirin (325 mg orally/day) and heparin (1,000 U intravenously/h) for 48 h until catheterization was performed to determine the primary study end point, namely, infarct-related artery patency at 48 h. Secondary end points were in-hospital death, left ventricular ejection fraction at 48 h and time to treatment.

RESULTS

There was no difference in the baseline characteristics of the two treatment groups. Overall patient age was 56 +/- 10 years, 83% of patients were male, 11% had prior infarction, 40% had anterior infarction and 97% were in Killip class I or II. Although time to treatment was delayed in the angioplasty group (238 +/- 112 vs. 179 +/- 98 min, p = 0.005), there was no difference in 48-h infarct-related artery patency or left ventricular ejection fraction (patency 74% vs. 80%; ejection fraction 59 +/- 13% vs. 57 +/- 13%; angioplasty vs. streptokinase, p = NS for both). There were no major bleeding events, and the mortality rate with angioplasty (6%) and streptokinase (2%) did not differ (p = NS).

CONCLUSIONS

These results suggest that intravenous thrombolytic therapy might be preferred over coronary angioplasty for most patients because of the often shorter time to treatment.

[Thrombolysis with intravenous APSAC in patients with acute myocardial infarction]

PURPOSE

Analysis of the first 20 patients with acute myocardial infarction (AMI) who were treated with intravenous APSAC.

METHODS

Twenty patients with AMI less than 6 hours of duration of symptoms were treated with IV APSAC bolus of 30 mg. Seventeen were males, ages ranging between 40 and 73 (mean 54) years. The first angiographic study was performed in 90 minutes and 5-7 days after drug administration.

RESULTS

In the angiographic study performed at 90 minutes the infarct--related artery were left anterior descending (LAD) in 7 patients (35%), right coronary artery (RCA) in 9 (45%) and left circumflex (LCX) in 4 (20%). In 14 (70%) of the patients had patent infarct-related artery and the mean of left ventricular ejection fraction (LVEF) was 0.49 +/- 0.15. In six non recanalized patients the mean LVEF was 0.40 +/- 0.14. No complications were observed, and in the second angiographic study one patient showed reocclusion of the infarct-related artery.

CONCLUSION

Because of easy application (IV bolus), no complication and high rate of early recanalization, IV APSAC seems to be an efficient thrombolytic agent in the treatment of patients with AMI.

[Treatment of pulmonary thromboembolism with extrinsic plasminogen activator. A case report]

A 49 year-old woman with acute pulmonary thromboembolism and severe hemodynamic impairment was successfully treated with tissue-type plasminogen activator (r-TPA). She did not have previous pulmonary or cardiac diseases. Thirty days after immobilization of the right ankle, she had a sudden onset of dyspnea, epigastrial pain and syncope. As heparin therapy was unsuccessful, 90 mg of IV r-TPA was administered. There was rapid clinical and hemodynamic improvement of her condition. Pulmonary scanning one week later was normal and she was discharged without symptoms 12 days after the acute episode.