Retrospective assessment of tolerability and efficacy of zoledronate in the palliative treatment of cancer-bearing dogs

Zoledronate is a bisphosphonate frequently used for the treatment of hypercalcaemia of malignancy and tumour-associated bone pain in dogs, however, there is a paucity of information regarding its use in veterinary medicine. The aim of this retrospective study was to report the tolerability of zoledronate in the palliative treatment of cancer-bearing dogs and secondarily to to assess the efficacy of zoledronate for the treatment of hypercalcaemia of malignancy. Thirty-seven dogs (22 with tumour-associated bone pain and 15 with hypercalcaemia of malignancy) that received 114 zoledronate infusions were included. Tolerability was assessed by the absence of post-zoledronate hypocalcaemia or other adverse events as defined by Veterinary Cooperative Oncology Group-Common Terminology Criteria for Adverse Events criteria. Efficacy was assessed by comparison of available ionized calcium levels before and after zoledronate administration in hypercalcaemic dogs. In 79% of zoledronate infusions, no adverse events were reported. The majority of adverse events which occurred in the other 21% of infusions could be attributed to concurrent chemotherapy or the underlying neoplastic disease. There was a small but significant increase in creatinine following treatment with zoledronate, however, none of the dogs developed clinically significant renal disease. In eight hypercalcaemic dogs with available ionized calcium following zoledronate administration, ionized calcium decreased rapidly within 7 days following treatment with zoledronate. Zoledronate is well-tolerated with few recorded adverse events, however, monitoring of serum creatinine is advised. Zoledronate seems to be effective in the treatment of hypercalcaemia of malignancy.

Asymptomatic bacteriuria in candidates for active treatment of renal stones: results from an international multicentric study on more than 2600 patients

The occurrence of asymptomatic bacteriuria concomitant to urolithiasis is an issue for patients undergoing renal stone treatment. Disposing of a preoperative urine culture is essential to reduce the risk of septic events. The endpoint of the study is to report which characteristics of candidates for renal stone treatment are frequently associated with positive urine culture. 2605 patients were retrospectively enrolled from 14 centers; inclusion criteria were age > 18 and presence of a single renal stone 1-2 cm in size. The variables collected included age, gender, previous renal surgery, comorbidities, skin-to-stone distance, stone size, location, density, presence of hydronephrosis. After a descriptive analysis, the association between continuous and categorical variables and the presence of positive urine culture was assessed using a logistic regression model. Overall, 240/2605 patients (9%) had preoperative bacteriuria. Positive urine culture was more frequent in females, patients with previous renal interventions, chronic kidney disease, congenital anomalies, larger stones, increased density. Multivariate analysis demonstrated that previous renal interventions (OR 2.6; 95% CI 1.9-3.4; p < 0.001), renal-related comorbidities (OR 1.31; 95% CI 1.19-1.4; p < 0.001), higher stone size (OR 1.06; 95% CI 1.02-1.1; p = 0.01) and density (OR 1.00; 95% CI 1.0-1.00; p = 0.02) were associated with bacteriuria; male gender and lower caliceal location were inversely related to it. Beyond expected risk factors, such as female gender, other parameters are seemingly favoring the presence of positive urine culture. The awareness of variables associated with bacteriuria allows to assess which individuals are at increased risk of presenting bacteriuria and reduce the rate of septic complications.

3D-Conformal Radiation Therapy in Prostate Cancer. Technical Considerations after 5 Years of Experience and 334 Patients Treated at the Istituto Europeo Di Oncologia of Milan, Italy

Aims and Background

To report the technique of 3D-conformal radiation therapy (3D-CRT) currently used at our Institute for the treatment of prostate cancer with a curative intent. A critical review of the technical aspects of the technique is provided.

Methods and Study Design

Between December 1995 and October 2000, 334 patients with biopsy-proven adenocarcinoma of the prostate were treated with 3D-CRT. All patients were treated in a prone position with 15 MV X-ray beams and a 6-field technique for all but 20 patients, who were treated with a 3-field technique. Patients were simulated with the rectum and bladder empty. To ensure reproducible positioning, custom-made polyurethane foam or thermoplastic casts were produced for each patient. Subsequently, consecutive CT scan slices were obtained. The clinical target volume and critical organs (rectum and bladder) were identified on each CT slice. The beam's eye view technique was used to spatially display these structures, and the treatment portals were manually shaped based on the images obtained. The beam apertures were initially realized by conventional Cerrobend blocks (48 patients), which were replaced in October 1997 by a computer-driven multi-leaf collimator. The total target dose prescribed at the ICRU point is 76 Gy, delivered in 38 fractions and 54 days. The seminal vesicles are excluded at 70 Gy. Dose-volume histograms were obtained for all patients. If more than 30% of the bladder and/or more than 20% of the rectum receive >95% of the prescribed total dose, the treatment plan is judged as unsatisfactory and is adjusted. The dose-volume histogram can be improved by changing the beam's arrangement and/or weights or by introducing or modifying the wedge filters.

Conclusions

3D-CRT in prostate cancer patients is a highly sophisticated and time-consuming method of dose delivery. Important technical issues remain to be clarified.

Neonatal Fc receptor is involved in the protection of fibrinogen after its intake in peripheral blood mononuclear cells

Background

Fibrinogen is a central player in the blood coagulation cascade and one of the most abundant plasma proteins. This glycoprotein also triggers important events (e.g., cell spreading, the respiratory burst and degranulation) in neutrophil cells via a α_Mβ₂ integrin-mediated binding to the cell surface. Yet, little is known about the interaction of fibrinogen with leukocytes other than neutrophils or stimulated monocytes, although high amounts of fibrinogen protein can also be found in lymphocytes, particularly in T-cells. The aim of the present work is to unveil the dynamics and the function of fibrinogen intake in T-cells.

Methods

Using the Jurkat cell line as a T-cells model we performed fibrinogen intake/competition experiments. Moreover, by means of a targeted gene knock-down by RNA-interference, we investigated the dynamics of the intake mechanism.

Results

Here we show that (i) fibrinogen, although not expressed in human peripheral blood mononuclear cells, can be internalized by these cells; (ii) fibrinogen internalization curves show a hyperbolic behavior, which is affected by the presence of serum in the medium, (iii) FITC-conjugated fibrinogen is released and re-internalized by adjacent cells, (iv) the presence of human serum albumin (HSA) or immunoglobulin G (IgG), which are both protected from intracellular degradation by the interaction with the neonatal Fc receptor (FcRn), results in a decreased amount of internalized fibrinogen, and (v) FcRn-knockdown affects the dynamics of fibrinogen internalization.

Conclusions

We demonstrated here for the first time that fibrinogen can be internalized and released by T-lymphocyte cells. Moreover, we showed that the presence of serum, HSA or IgG in the culture medium results in a reduction of the amount of internalized fibrinogen in these cells. Thus, we obtained experimental evidence for the expression of FcRn in T-lymphocyte cells and we propose this receptor as involved in the protection of fibrinogen from intracellular lysosomal degradation.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1446-2) contains supplementary material, which is available to authorized users.

Fowlpoxvirus recombinants coding for the CIITA gene increase the expression of endogenous MHC-II and Fowlpox Gag/Pro and Env SIV transgenes

A complete eradication of an HIV infection has never been achieved by vaccination and the search for new immunogens that can induce long-lasting protective responses is ongoing. Avipoxvirus recombinants are host-restricted for replication to avian species and they do not have the undesired side effects induced by vaccinia recombinants. In particular, Fowlpox (FP) recombinants can express transgenes over long periods and can induce protective immunity in mammals, mainly due to CD4-dependent CD8⁺ T cells. In this context, the class II transactivator (CIITA) has a pivotal role in triggering the adaptive immune response through induction of the expression of class-II major histocompatibility complex molecule (MHC-II), that can present antigens to CD4⁺ T helper cells. Here, we report on construction of novel FPgp and FPenv recombinants that express the highly immunogenic SIV Gag-pro and Env structural antigens. Several FP-based recombinants, with single or dual genes, were also developed that express CIITA, driven from H6 or SP promoters. These recombinants were used to infect CEF and Vero cells in vitro and determine transgene expression, which was evaluated by real-time PCR and Western blotting. Subcellular localisation of the different proteins was evaluated by confocal microscopy, whereas HLA-DR or MHC-II expression was measured by flow cytometry. Fowlpox recombinants were also used to infect syngeneic T/SA tumour cells, then injected into Balb/c mice to elicit MHC-II immune response and define the presentation of the SIV transgene products in the presence or absence of FPCIITA. Antibodies to Env were measured by ELISA. Our data show that the H6 promoter was more efficient than SP to drive CIITA expression and that CIITA can enhance the levels of the gag/pro and env gene products only when infection is performed by FP single recombinants. Also, CIITA expression is higher when carried by FP single recombinants than when combined with FPgp or FPenv constructs and can induce HLA-DR cell surface expression. However, in-vivo experiments did not show any significant increase in the humoral response. As CIITA already proved to elicit immunogenicity by improving antigen presentation, further in-vivo experiments should be performed to increase the immune responses. The use of prime/boost immunisation protocols and the oral administration route of the recombinants may enhance the immunogenicity of Env peptides presented by MHC-II and provide CD4⁺ T-cell stimulation.

Tumor Immunology meets…Immunology: Modified cancer cells as professional APC for priming naïve tumor-specific CD4+ T cells

Although recent therapeutic approaches have revitalized the enthusiasm of the immunological way to combat cancer, still the comprehension of immunity against tumors is largely incomplete. Due to their specific function, CD8+ T cells with cytolytic activity (CTL) have attracted the attention of most investigators because CTL are considered the main effectors against tumor cells. Nevertheless, CTL activity and persistence is largely dependent on the action of CD4+ T helper cells (TH). Thus establishment of tumor-specific TH cell response is key to the optimal response against cancer. Here we describe emerging new strategies to increase the TH cell recognition of tumor antigens. In particular, we review recent data indicating that tumor cells themselves can act as surrogate antigen presenting cells for triggering TH response and how these findings can help in constructing immunotherapeutic protocols for anti-cancer vaccine development.

Tripartite Motif-Containing Protein 22 Interacts with Class II Transactivator and Orchestrates Its Recruitment in Nuclear Bodies Containing TRIM19/PML and Cyclin T1

Among interferon (IFN) inducible antiviral factors both tripartite motif-containing protein 22 (TRIM22) and class II transactivator (CIITA) share the capacity of repressing human immunodeficiency virus type 1 (HIV-1) proviral transcription. TRIM22 is constitutively expressed in a subset of U937 cell clones poorly permissive to HIV-1 replication, whereas CIITA has been shown to inhibit virus multiplication in both T lymphocytic and myeloid cells, including poorly HIV-1 permissive U937 cells, by suppressing Tat-mediated transactivation of HIV-1 transcription. Therefore, we tested whether TRIM22 and CIITA could form a nuclear complex potentially endowed with HIV-1 repressive functions. Indeed, we observed that TRIM22, independent of its E3 ubiquitin ligase domain, interacts with CIITA and promotes its recruitment into nuclear bodies. Importantly, TRIM19/promyelocytic leukemia (PML) protein, another repressor of HIV-1 transcription also acting before proviral integration, colocalize in these nuclear bodies upon TRIM22 expression induced by IFN-γ. Finally, tTRIM22 nuclear bodies also contained CyclinT1, a crucial elongation factor of HIV-1 primary transcripts. These findings show that TRIM22 nuclear bodies are a site of recruitment of factors crucial for the regulation of HIV-1 transcription and highlight the potential existence of a concerted action between TRIM22, CIITA, and TRIM19/PML to maintain a state of proviral latency, at least in myeloid cells.

Apoferritin nanocage as streptomycin drug reservoir: Technological optimization of a new drug delivery system

The aim of this study is to formulate and characterize streptomycin-loaded apoferritin nanoparticles (ApoStrep NPs) for their potential therapeutic use in bacterial resistant infections (i.e. tuberculosis). ApoStrep NPs were prepared by disassembly/reassembly process via pH method and changing apoferritin/drug molar ratio, purified by dialyses process also associated with gel filtration chromatography and characterized in their chemico-physical and technological parameters as yield, size distribution, polidispersivity, morphology, internal structure, zeta potential and loading efficacy. The results showed that spherical reproducible NPs could be obtained by using apoferritin/drug molar ratio lower than 1:25 and purification based on the combination of dialysis and gel filtration chromatography. Photon correlation spectroscopy, Uv-visible detection and electron microscopy showed the maintenance of the native apoferritin chemico-physical properties and structure. When formulated with apoferritin/drug 1:10 and 1:25 molar ratio, ApoStrep NPs showed remarkable encapsulation efficacy (35% and 28%, respectively) along with kinetic profile of drug delivery, approximately 15% at 37 °C in 72h, as evidenced by "in vitro" release experiments.

CIITA-driven MHC class II expressing tumor cells can efficiently prime naive CD4+ TH cells in vivo and vaccinate the host against parental MHC-II-negative tumor cells

Our previous studies showed that non-immunogenic H-2^d tumor cells of distinct epithelial histotypes can become highly immunogenic, induce a protective CD4⁺ T cell response and vaccinate the animals against parental MHC-II-negative cells if they are rendered MHC class II-positive by stable transfection with the Air-1-encoded MHC-II transcriptional activator CIITA. These studies did not establish, however, whether tumor immunity was the consequence of a direct priming of naive CD4⁺ T lymphocytes by CIITA-driven MHC-II-expressing tumor cells or by MHC-II-tumor antigen complexes engulfed by dendritic cells (DC) and exposed on the surface of these professional antigen presenting cells (APC). In the present investigation, we provide definitive evidence that CIITA-tumor cells are the crucial APC in vivo for CD4⁺ T cell priming. By using a transgenic H-2^b mouse model, the CD11c.DTR C57BL/6 mice, in which DC can be functionally deleted by administration of diphteria toxin, we show that CIITA-tumor cells of two distinct histotypes can be rejected or strongly retarded in their growth in DC-deleted mice. To rule out that in absence of DC, other professional APC could prime naive CD4⁺ T cells, we deleted the macrophages in CD11c.DTR C57BL/6 mice by administration of liposome Clodronate and still obtained rejection or strong retardation in tumor growth of CIITA-tumor cells. Our results challenge the diffuse belief that non-professional APC cannot efficiently prime naive T cells in vivo. Moreover, the demonstration of the general validity of our approach in different genetic backgrounds may open a way for new strategies of antitumor treatment in clinical settings.

Abstract A014: CIITA dependent MHC class II IA expression in tumor cells triggers CD4 T cell protective and long lasting antitumor immunity

We previously demonstrated the generation of a CD4 T cell-specific long lasting anti-tumor immune response in the H-2d BALB/c mouse model by using tumor cells that have been genetically modified with CIITA to express MHC-II I-E and I-A molecules. We have now investigated the pertinence of this approach in the H-2b C57BL/6 mouse model despite the defect in their I-Eα gene and thus the lack of expression of I-E subset. To this purpose we injected in vivo the CIITA-driven I-A-only MHC-II-positive LLC (lewis Lung Carcinoma) and MC38 colon carcinoma in the C57BL/6 mice and their growth rate along with the recipient's immune response were analyzed. The CIITA-transfected, MHC-II-positive tumor cells were either completely rejected or showed a significant growth retardation compared to the MHC-II-negative parental tumor. The protected mice were re-injected with the parental tumors and a complete rejection was obtained proving that a specific long lasting immune response was triggered by the CIITA-transfected tumors. Furthermore, total splenocytes or purified CD4+, CD8+ T cells and B cells were transferred from the vaccinated recipients to naïve recipients that were co-injected with the parental tumor cells and the results showed that CD4+ TH cells were the main effectors of the immune response against the tumor cells. Interestingly, similar results were obtained in C57BL/6-DOG transgenic mice whose dendritic cells could be conditionally ablated after administration of Diphteria toxin. These results demonstrate the validity of triggering a specific, long-lasting anti-tumor immune response using CIITA-driven MHC class II positive tumor cells of different MHC haplotype as stimulators. Importantly, the results establish that expression of a single MHC-II restriction element, I-A, in tumor cells is sufficient to trigger CD4+ TH cell protective immune response, strongly suggesting that the relevant tumor-associated antigenic repertoire can be displayed without the need of the I-E restriction element. Finally, these results strongly suggest that CIITA-modified tumor cells can act as antigen presenting cells in vivo to prime naïve CD4+ TH cells against tumor antigens.

Citation Format: Farah Bou Nasser Eddine, Greta Forlani, Giovanna Tosi, Roberto S. Accolla. CIITA dependent MHC class II IA expression in tumor cells triggers CD4 T cell protective and long lasting antitumor immunity [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 A014.

A novel variant of the infectious bronchitis virus resulting from recombination events in Italy and Spain

Infectious bronchitis is considered to be one of the most devastating diseases in poultry. Control of its spread is typically attempted through biosecurity measures and extensive vaccination. However, the remarkable genetic and antigenic variability of the virus, which originate from both mutations and recombination events, represents an unsolved challenge for this disease. The present study reports on the emergence and spread of recombinant clusters detected in Italy and Spain between 2012 and 2014. A total of 36 Spanish and Italian infectious bronchitis virus (IBV) field strains were investigated and genetically characterized using phylogenetic, molecular, recombination and selection pressure analyses of the complete S1 gene. Based on the partial S1 sequencing, 27 IBV strains originating from Spain and nine from Italy were initially classified as being closely related to the Guandong/Xindadi (XDN) genotype. Phylogenetic analysis of the complete S1 gene revealed that the XDN strains formed a homogeneous clade with the Spanish IBV isolates within the QX genotype, whereas there was higher variability within the Italian strains. Recombination analysis determined that these strains belonged to four groups, which originated from independent recombination events between the QX and 793B IBV genotypes. Our data support the hypothesis of two different scenarios: firstly, in Spain, the large and homogeneous clade probably originated from a single offspring of the recombinant founder, which became dominant and spread throughout the country. Secondly, the nine Italian recombinants, which are characterized by three different recombination patterns, probably represent less fitted strains, because they were less viable with respect to their recombinant parents.

EXPLOITING THE VERSATILITY OF CHOLESTEROL IN NANOPARTICLES FORMULATION

The biocompatibility of polymers, lipids and surfactants used to formulate is crucial for the safe and sustainable development of nanocarriers (nanoparticles, liposomes, micelles, and other nanocarriers). In this study, Cholesterol (Chol), a typical biocompatible component of liposomal systems, was formulated in Chol-based solid nanoparticles (NPs) stabilized by the action of surfactant and without the help of any other formulative component. Parameters as type (Solutol HS 15, cholic acid sodium salt, poly vinyl alcohol and Pluronic-F68), concentration (0.2; 0.5 and 1% w/v) of surfactant and working temperature (r.t. and 45°C) were optimized and all samples characterized in terms of size, zeta potential, composition, thermal behavior and structure. Results demonstrated that only Pluronic-F68 (0.5% w/v) favors the organization of Chol chains in structured NPs with mean diameter less than 400nm. Moreover, we demonstrated the pivotal role of working temperature on surfactant aggregation state/architecture/stability of Chol-based nanoparticles. At room temperature, Pluronic-F68 exists in solution as individual coils. In this condition, nanoprecipitation of Chol formed the less stable NPs with a 14±3% (w/w) of Pluronic-F68 prevalently on surface (NP-Chol/0.5). On the contrary, working near the critical micelle temperature (CMT) of surfactant (45°C), Chol precipitates with Pluronic-F68 (9±5% w/w) in a compact stable matricial structure (NP-Chol/0.5-45). In vitro studies highlight the low toxicity and the affinity of NP-Chol/0.5-45 for neuronal cells suggesting their potential applicability in pathologies with a demonstrated alteration of neuronal plasticity and synaptic communication (i.e. Huntington's disease).

The MHC-II transactivator CIITA inhibits Tat function and HIV-1 replication in human myeloid cells

Background

We previously demonstrated that the HLA class II transactivator CIITA inhibits HIV-1 replication in T cells by competing with the viral transactivator Tat for the binding to Cyclin T1 subunit of the P-TEFb complex. Here, we analyzed the anti-viral function of CIITA in myeloid cells, another relevant HIV-1 target cell type. We sinvestigated clones of the U937 promonocytic cell line, either permissive (Plus) or non-permissive (Minus) to HIV-1 replication. This different phenotype has been associated with the expression of TRIM22 in U937 Minus but not in Plus cells.

Methods

U937 Plus cells stably expressing CIITA were generated and HLA-II positive clones were selected by cell sorting and cloning. HLA and CIITA proteins were analyzed by cytofluorometry and western blotting, respectively. HLA-II DR and CIITA mRNAs were quantified by qRT-PCR. Tat-dependent transactivation was assessed by performing the HIV-1 LTR luciferase gene reporter assay. Cells were infected with HIV-1 and viral replication was evaluated by measuring the RT activity in culture supernatants.

Results

CIITA was expressed only in HLA-II-positive U937 Minus cells, and this was strictly correlated with inhibition of Tat-dependent HIV-1 LTR transactivation in Minus but not in Plus cells. Overexpression of CIITA in Plus cells restored the suppression of Tat transactivation, confirming the inhibitory role of CIITA. Importantly, HIV-1 replication was significantly reduced in Plus-CIITA cells with respect to Plus parental cells. This effect was independent of TRIM22 as CIITA did not induce TRIM22 expression in Plus-CIITA cells.

Conclusions

U937 Plus and Minus cells represent an interesting model to study the role of CIITA in HIV-1 restriction in the monocytic/macrophage cell lineage. The differential expression of CIITA in CIITA-negative Plus and CIITA-positive Minus cells correlated with their capacity to support or not HIV-1 replication, respectively. In Minus cells CIITA targeted the viral transactivator Tat to inhibit HIV-1 replication. The generation of Plus-CIITA cells was instrumental to demonstrate the specific contribution of CIITA in terms of inhibition of Tat activity and HIV-1 restriction, independently from other cellular factors, including TRIM22. Thus, CIITA acts as a general restriction factor against HIV-1 not only in T cells but also in myeloid cells.

Nanoimaging: photophysical and pharmaceutical characterization of poly-lactide-co-glycolide nanoparticles engineered with quantum dots

Quantum dots (QDs) and polymeric nanoparticles (NPs) are considered good binomials for the development of multifunctional nanomedicines for multimodal imaging. Fluorescent imaging of QDs can monitor the behavior of QD-labeled NPs in both cells and animals with high temporal and spatial resolutions. The comprehension of polymer interaction with the metallic QD surface must be considered to achieve a complete chemicophysical characterization of these systems and to describe the QD optical properties to be used for their unequivocal identification in the tissue. In this study, by comparing two different synthetic procedures to obtain polymeric nanoparticles labeled with QDs, we investigated whether their optical properties may change according to the formulation methods, as a consequence of the different polymeric environments. Atomic force microscopy, transmission electron microscopy, confocal and fluorescence lifetime imaging microscopy characterization demonstrated that NPs modified with QDs after the formulation process (post-NPs-QDs) conserved the photophysical features of the QD probe. In contrast, by using a polymer modified with QDs to formulate NPs (pre-NPs-QDs), a significant quenching of QD fluorescence and a blueshift in its emission spectra were observed. Our results suggest that the packaging of QDs into the polymeric matrix causes a modification of the QD optical properties: these effects must be characterized in depth and carefully considered when developing nanosystems for imaging and biological applications.

Abstract B047: Adequate Antigen Availability (AAA) in antitumor immunity: Definition and consequences for novel strategies of tumor prevention and antitumor treatment

Present immunopreventive and immunotherapeutic approaches against cancer suffer from the limitation of being not “sterilizing” procedures, as very poor protection against the tumor is obtained. Thus, newly conceived anti-tumor strategies of intervention are urgently needed. Here we introduce the concept of Adequate Antigen Availability (AAA) defined as the optimal tumor antigen dose and related antigen processing and MHC class II-restricted presentation necessary to trigger efficient tumor-specific TH cells (1). We will present results on a preventive anti-tumor vaccination system that consists in injecting tumor cells genetically modified to constitutively express MHC class II molecules by transfecting the MHC-II transcriptional activator CIITA. AAA is generated by the function of tumor's newly expressed MHC-II molecules to present tumor-associated antigens to tumor-specific CD4+ TH cells. We will show that tumor rejection against the CIITA-transfected neoplastic cells is brought about by the generation of persistent anti-tumor TH cell memory, responsible of protecting the animals from subsequent challenges with parental, untransfected tumor cells. This approach has been validated in tumor cells of different histotypic origin and of distinct MHC genotype (H-2d and H-2b). Importantly, the anti-tumor TH cell response modifies the tumor microenvironment, favouring the infiltration of CD4+ TH cells, CD8+ cytolytic T cells and granulocytes and dramatically reducing both intratumoral and lymphnode infiltration of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSC). Thus the optimal initiation of the adaptive immune response, dictated by AAA, is sufficient to reorient the tumor microenvironment from a pro-tumor to an anti-tumor microenvironment. Our approach is, at present, applied to human clinical setting in hepatocellular carcinomas (2) whereby human tumor cells are rendered HLA class II-positive by CIITA genetic transfer with the aim to purify and sequence immunogenically relevant HLA class II-bound tumor–associated antigenic (TAA) peptides. In conjunction with similarly derived HLA class I-restricted TAA peptides, they will be the basis for the construction of a multi-peptide, multi-epitope vaccine that can target both CD4+ TH and CD8+ CTL anti-tumor responses.

References:

1. Accolla RS, Lombardo L, Abdallah R, Raval G, Forlani G, Tosi G. Boosting the MHC class II-restricted tumor antigen presentation to CD4+ T helper cells: a critical issue for triggering protective immunity and re-orienting the tumor microenvironment toward an anti-tumor state. Front Oncol. 2014 Feb 18;4:32

2. Hepavac, Cancer Vaccine Development for Hepatocellular Carcinoma. FP7-HEALTH-2013, Collaborative Project, Project number: 602893

Citation Format: Roberto S. Accolla, Greta Forlani, Giovanna Tosi. Adequate Antigen Availability (AAA) in antitumor immunity: Definition and consequences for novel strategies of tumor prevention and antitumor treatment. [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 B047.

Abstract B048: The MHC class II transactivator CIITA inhibits the persistent activation of NF-kB by Human T cell Lymphotropic Virus type-1 Tax-1 oncoprotein

Human T cell Lymphotropic Virus type-1 (HTLV-1) Tax-1 protein, a key mediator of HTLV-1-induced T-cell transformation, deregulates diverse cell-signalling pathways. Among them, the NF-kB pathway is constitutively activated by Tax-1, which binds to NF-kB family members and activates the IkB-kinase (IKK). Upon phosphorylation-dependent degradation of IkB, NF-kB migrates into the nucleus and mediates Tax-1-stimulated gene expression. We show that CIITA, the transcriptional regulator of Major Histocompatibility Complex Class II genes, inhibits the activation of the canonical NF-kB pathway by Tax-1 and map the region mediating this effect. CIITA affects the subcellular localization of Tax-1, which is mostly retained in the cytoplasm, and this correlates with an impaired migration of RelA into the nucleus. Cytoplasmic and nuclear CIITA mutants reveal that CIITA exploits different strategies to suppress Tax-1-mediated NF-kB activation in both subcellular compartments. CIITA interacts with Tax-1 without preventing Tax-1 binding to both IKKg and RelA. Nevertheless, CIITA affects Tax-1-induced IKK activity causing the retention of the inactive p50/RelA/IkB complex in the cytoplasm. Nuclear CIITA associates with Tax-1/RelA in nuclear bodies blocking the activation of NF-kB-responsive genes by Tax-1. Thus, CIITA inhibits critical cytoplasmic and nuclear steps of Tax-1-mediated NF-kB activation. These results, together with our previous finding that CIITA acts as a restriction factor inhibiting Tax-1-promoted HTLV-1 gene expression and replication, indicate that CIITA is a versatile molecule that might also counteract Tax-1 transforming activity. Unveiling the molecular basis of CIITA-mediated inhibition of Tax-1 functions may be important in defining new strategies to control HTLV-1 spreading and oncogenic potential.

Citation Format: Greta Forlani, Rawan Abdallah, Roberto S. Accolla, Giovanna Tosi. The MHC class II transactivator CIITA inhibits the persistent activation of NF-kB by Human T cell Lymphotropic Virus type-1 Tax-1 oncoprotein. [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 B048.

Study of oral cavity lesions by infrared spectroscopy

Fourier transform infrared (FTIR) microspectroscopy is considered a useful tool in the biomedical field, for analysing in situ and at cellular level, very small areas of tissues and cells, with minimal sample preparation and without the use of stains or probes. This spectroscopic technique has been successfully applied to analyse biological samples from patients affected by tumoral pathologies, with particular attention to oral cavity lesions. In this study, we describe the application of FTIR microspectroscopy to characterize and discriminate the most recurrent benign and malignant diseases of oral cavity compartment. Infrared maps were acquired on tissues affected by the following pathologies: squamous cell carcinoma, adenoid cystic carcinoma, polymorphous low-grade adenocarcinoma, squamous dysplasia, keratocystic odontogenic tumor, radicular cyst, residual cyst, unicystic ameloblastoma, and ameloblastic fibroma, together with healthy tissue samples (used as control group). The epithelial and connective components of all samples were distinguished and submitted to multivariate analysis. The results were in agreement with histological suggestions.

Exploiting Bacterial Pathways for BBB Crossing with PLGA Nanoparticles Modified with a Mutated Form of Diphtheria Toxin (CRM197): In Vivo Experiments

Drugs can be targeted to the brain using polymeric nanoparticles (NPs) engineered on their surface with ligands able to allow crossing of the blood-brain barrier (BBB). This article aims to investigate the BBB crossing efficiency of polymeric poly lactide-co-glycolide (PLGA) NPs modified with a mutated form of diphtheria toxin (CRM197) in comparison with the results previously obtained using PLGA NPs modified with a glycopeptide (g7-NPs). Different kinds of NPs, covalently coupled PLGA with different fluorescent probes (DY405, rhodamine-B base and DY675) and different ligands (g7 and CRM197) were tested in vivo to assess their behavior and trafficking. The results highlighted the possibility to distinguish the different kinds of simultaneously administered NPs and to emphasize that CRM-197 modified NPs and g7-NPs can cross the BBB at a similar extent. The analysis of BBB crossing and of the neuronal tropism of CRM197 modified NPs, along with their BBB crossing pathways were also developed. In vivo pharmacological studies performed on CRM197 engineered NPs, loaded with loperamide, underlined their ability as drug carriers to the CNS.

Localization, quantification and interaction with host factors of endogenous HTLV-1 HBZ protein in infected cells and ATL

BACKGROUND

Human T cell lymphotropic virus type 1 (HTLV-1) is the etiological agent of a severe form of neoplasia designated Adult T cell Leukaemia (ATL). It is widely accepted that the viral transactivator Tax-1 is the major viral product involved in the onset, but not in the maintenance, of neoplastic phenotype, as only 30-40% of ATL cells express Tax-1. It has been recently demonstrated that HBZ (HTLV-1 bZIP factor), a protein encoded by the minus strand of HTLV-1 genome, constantly expressed in infected cells and in ATL tumor cells, is also involved in the pathogenesis of leukaemia. The full role played by HBZ in oncogenesis is not clarified in detail also because of the limited availability of tools to assess quantitative expression, subcellular location and interaction of HBZ with host factors in ATL.

RESULTS

By the use of the first reported monoclonal antibody against HBZ, 4D4-F3, generated in our laboratory it has been possible to carefully assess for the first time the above parameters in HTLV-1 chronically infected cells and, most importantly, in fresh leukemic cells from patients. Endogenous HBZ is expressed in speckle-like structures localized in the nucleus. The calculated number of endogenous HBZ molecules varies between 17.461 and 39.615 molecules per cell, 20- to 50-fold less than the amount expressed in HBZ transfected cells used by most investigators to assess the expression, function and subcellular localization of the viral protein. HBZ interacts in vivo with p300 and JunD and co-localizes only partially, and depending on the amount of expressed HBZ, not only with p300 and JunD but also with CBP and CREB2.

CONCLUSIONS

The possibility to study endogenous HBZ in detail may significantly contribute to a better delineation of the role of HBZ during HTLV-1 infection and cellular transformation.

Nutlin-3 loaded nanocarriers: Preparation, characterization and in vitro antineoplastic effect against primary effusion lymphoma

In this investigation, Nutlin-3 (Nut3), a novel antitumor drug with low water solubility (<0.1mg/L at 25°C), was loaded into liposomes (Lipo-Nut3), polymeric nanoparticles (NPs-Nut3) and nanoparticles engineered with an antibody direct against Syndecan-1/CD 138 (Syn-NPs-Nut3) to obtain carriers targeted to PEL (primary effusion lymphoma). The physicochemical properties of these carriers were determined. Atomic force microscopy showed that all the particles were well formed and spherical in shape. The presence of the antibody on surface led to a significant increase of mean diameter (280 ± 63 nm), PDI (0.3) and the shift of zeta potential towards neutrality (-1 mV). The entrapment efficiency of Lipo-Nut3, NPs-Nut3 and Syn-NPs-Nut3 was 30, 52 and 29%, and drug loading was 1.4, 4.5 and 2.6%, respectively. By performing cytofluorimetric analyses and bromodeoxyuridine (BrdU) assay, the efficacy of nanocarriers to deliver the antineoplastic drug into a PEL cell line namely BCBL-1 (immortalized body cavity B-cell lymphoma) was investigated. Two days after the treatment with 20 μM of Syn-NPs-Nut3, the cell density decreased at about 60% while the cell viability decreased at 56% only 5 days after transfection, when compared with untreated cells. A cell cycle arrest was observed with a significant decrease of cells in S-phase and increasing of apoptotic cell, if compared with untreated control. These results confirms the potential of nanocarriers approaches to deliver antitumor drug with unfavorable chemico-physical properties. Moreover, this study strongly suggests that Syn-NPs-Nut3 can be a valuable drug carrier system for the treatment of PEL lymphoma.

Boosting the MHC Class II-Restricted Tumor Antigen Presentation to CD4+ T Helper Cells: A Critical Issue for Triggering Protective Immunity and Re-Orienting the Tumor Microenvironment Toward an Anti-Tumor State

Although the existence of an immune response against tumor cells is well documented, the fact that tumors take off in cancer patients indicates that neoplastic cells can circumvent this response. Over the years many investigators have described strategies to rescue the anti-tumor immune response with the aim of creating specific and long-lasting protection against the disease. When exported to human clinical settings, these strategies have revealed in most cases a very limited, if any, positive outcome. We believe that the failure is mostly due to the inadequate triggering of the CD4+ T helper (TH) cell arm of the adaptive immunity, as TH cells are necessary to trigger all the immune effector mechanisms required to eliminate tumor cells. In this review, we focus on novel strategies that by stimulating MHC class II-restricted activation of TH cells generate a specific and persistent adaptive immunity against the tumor. This point is of critical importance for both preventive and therapeutic anti-tumor vaccination protocols, because adaptive immunity with its capacity to produce specific, long-lasting protection and memory responses is indeed the final goal of vaccination. We will discuss data from our as well as other laboratories which strongly suggest that triggering a specific and persistent anti-tumor CD4+ TH cell response stably modify not only the tumor microenvironment but also tumor-dependent extratumor microenvironments by eliminating and/or reducing the blood-derived tumor infiltrating cells that may have a pro-tumor growth function such as regulatory CD4+/CD25+ T cells and myeloid-derived-suppressor cells. Within this frame, therefore, we believe that the establishment of a pro-tumor environment is not the cause but simply the consequence of the tumor strategy to primarily counteract components of the adaptive cellular immunity, particularly TH lymphocytes.

Investigating human T cell lymphotropic retrovirus (HTLV) Tax function with molecular and immunophenotypic techniques

Human T cell Lymphotropic Viruses 1 and 2 (HTLV-1 and HTLV-2) are the first described human retroviruses. HTLV-1 is the causative agent of an aggressive malignancy of CD4+ T lymphocytes named adult T-cell leukemia/lymphoma (ATLL) and of a chronic neurological disease known as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-2 shares many similarities with HTLV-1, but displays lower or absent association to diseases. Among the proteins encoded by HTLVs, the viral transactivator Tax exerts an essential role in viral transcription as well as in cell transformation. Different experimental methods to study Tax activity on HTLV-LTR promoter and Tax subcellular distribution are described. Emphasis is given to the functional and physical interaction between Tax-1/Tax-2 and cellular cofactors which may have an impact on the infectivity process of the HTLVs and on the capacity of cell transformation.

Industrial wastes from the boat-building sector in the Marche Region (Italy): a parametric and chemical-physical characterization

Using the renowned leisure boat-building sector in the Marche Region (Italy) as a case-study, this paper addresses the characterization of (1) the industrial waste generation from the building of composite material-based boats and (2) some chemical-physical properties of representative types of boat-building residues (plastic foam, hardened resin, fibre-reinforced composite residues, and sanding dust). A parametric evaluation based on the number of employees gave a representative unit generation rate per employee (UGRpE) of 1.47 tons(waste) employee(-1) year(-1) for the entire Marche regional boatbuilding district, whereas evaluations carried out separately for three case-study companies provided values of 1.56, 3.07, and 1.12 tons(waste) employee(-1) year(-1) as representative for a mass-produced motor boat builder (case-study company '1'), a customized sailing boat builder (case-study company '2'), and a mould and structural component builder (case-study company '3'), respectively. The original proposal and evaluation of two additional generation rates based on physical characteristics intrinsic to the manufactured product, i.e. the unit generation rate per boat area (UGRpA) and per boat weight (UGRpW), confirmed the higher waste generation for the sailing boat builder(representative UGRpA and UGRpW values of 0.35 tons(waste) m(-2)(boat) year(-1) and 2. 71 tons(waste) tons(-1)(boat) year(-1), respectively) compared with the motor boat builder (representative UGRpA and UGRpW values of 0.06 tons(waste) m(-2)(boat) year(-1) and 0.49 tons(waste) tons(-1)(boat) year(-1), respectively). The chemical-physical property characterization of the selected residues revealed the following aspects: a general condition of low moisture contents; significant ash contents in the glass- and carbon-fibre composite residues and the correlated sanding dust; and relatively high energy content values in the overall range 14,144-32,479 kJ kg(-1), expressed as the lower heating value.

The MHC-II transactivator CIITA, a restriction factor against oncogenic HTLV-1 and HTLV-2 retroviruses: similarities and differences in the inhibition of Tax-1 and Tax-2 viral transactivators

The activation of CD4(+) T helper cells is strictly dependent on the presentation of antigenic peptides by MHC class II (MHC-II) molecules. MHC-II expression is primarily regulated at the transcriptional level by the AIR-1 gene product CIITA (class II transactivator). Thus, CIITA plays a pivotal role in the triggering of the adaptive immune response against pathogens. Besides this well known function, we recently found that CIITA acts as an endogenous restriction factor against HTLV-1 (human T cell lymphotropic virus type 1) and HTLV-2 oncogenic retroviruses by targeting their viral transactivators Tax-1 and Tax-2, respectively. Here we review our findings on CIITA-mediated inhibition of viral replication and discuss similarities and differences in the molecular mechanisms by which CIITA specifically counteracts the function of Tax-1 and Tax-2 molecules. The dual function of CIITA as a key regulator of adaptive and intrinsic immunity represents a rather unique example of adaptation of host-derived factors against pathogen infections during evolution.

Optimal MHC-II-restricted tumor antigen presentation to CD4+ T helper cells: the key issue for development of anti-tumor vaccines

Present immunoprevention and immunotherapeutic approaches against cancer suffer from the limitation of being not “sterilizing” procedures, as very poor protection against the tumor is obtained. Thus newly conceived anti-tumor vaccination strategies are urgently needed. In this review we will focus on ways to provide optimal MHC class II-restricted tumor antigen presentation to CD4+ T helper cells as a crucial parameter to get optimal and protective adaptive immune response against tumor. Through the description of successful preventive or therapeutic experimental approaches to vaccinate the host against the tumor we will show that optimal activation of MHC class II-restricted tumor specific CD4+ T helper cells can be achieved in various ways. Interestingly, the success in tumor eradication and/or growth arrest generated by classical therapies such as radiotherapy and chemotherapy in some instances can be re-interpreted on the basis of an adaptive immune response induced by providing suitable access of tumor-associated antigens to MHC class II molecules. Therefore, focussing on strategies to generate better and suitable MHC class II–restricted activation of tumor specific CD4+ T helper cells may have an important impact on fighting and defeating cancer.

Typing of a polymorphic human gene conferring susceptibility to insulin-dependent diabetes mellitus by picosecond-resolved FRET on non-purified/non-amplified genomic DNA

This work concerns the identification of the alleles of the polymorphic DQB1 gene of the human leukocyte antigen system, conferring susceptibility to the development of insulin-dependent diabetes mellitus (IDDM) in non-PCR amplified DNA samples and, more importantly, in crude cell extracts. Our method is based on the time-resolved analysis of a Förster energy-transfer mechanism that occurs in a dual-labelled fluorescent probe specific for the IDDM-associated DQB1-0201 allele. Such an oligonucleotide probe is labelled, at the two ends, by a pair of chromophores that operate as donor and acceptor in a Förster resonant energy transfer. The donor fluorescence is quenched with an efficiency that is strongly dependent on the donor-to-acceptor distance, hence on the configuration of the probe after hybridization with the various DQB1 alleles. By time-correlated single-photon counting, performed with an excitation/detection system endowed with 30-ps resolution, we measure the time-resolved fluorescence decay of the donor and discriminate, by means of the decay–time value, the DNA bearing the ‘susceptible’ allele from the DNAs bearing any other sequence in the same region of the DQB1 gene. We could also distinguish the presence of the DQB1-0201 allele in a homozygous versus a heterozygous condition.

Application of poly-L-lactide screws in flat foot surgery: histological and radiological aspects of bio-absorption of degradable devices

The flat foot in childhood is a condition frequently observed in orthopedic practice but it is still debated when and in which patients surgical corrective treatment is appropriate; recently, the application of poly-L-lactic-acid (PLLA) screws was proposed. The present study investigates a group of 33 patients treated with PLLA expansion endorthesis in order to evaluate the deformity correction. Clinical and radiological outcomes in patients were correlated with: a) morphological characterization of screws both before and after being removed from patients, when necessary; b) histological and bio-molecular evaluation of degradation processes of the implants, focusing attention on the correlation between the cellular cohort involved in inflammatory reaction and the bio-absorption degree of PLLA screws. Deformity correction was mostly achieved, with minimal need of screw removal; the results obtained clearly show the occurrence of chronic rather than acute inflammation in removed screw specimens. At the histological level, after biomaterial implantation, the sequence of events occurring in the surrounding tissues ultimately ends in the formation of foreign body giant cells (FBGCs) at the tissue/material interface; but the mechanisms which influence the fate of screw implants, i.e. the resolution of acute inflammation rather than the progression towards chronic inflammation, are of crucial importance for biodegradable materials like "polylactic acid". In fact, the FBGC response ensures a long-term mechanism which eliminates the foreign material from the body, but at the same time the implications of prolonged FBGC responses, which generate negative side effects, could significantly impede the healing progress.

Neurotrophic factors and neurodegenerative diseases: a delivery issue

Neurotrophic factors (NTFs) represent one of the most stimulating challenge in neurodegenerative diseases, due to their potential in neurorestoring and neuroprotection. Despite the large number of proofs-of-concept and evidences of their activity, most of the clinical trials, mainly regarding Parkinson's disease and Alzheimer's disease, demonstrated several failures of the therapeutic intervention. A large number of researches were conducted on this hot topic of neuroscience, clearly evidencing the advantages of NTF approach, but evidencing the major limitations in its application. The inability in crossing the blood-brain barrier and the lack of selectivity actually represent some of the most highlighted limits of NTFs-based therapy. In this review, beside an overview of NTF activity versus the main neuropathological disorders, a summary of the most relevant approaches, from invasive to noninvasive strategies, applied for improving NTF delivery to the central nervous systems is critically considered and evaluated.