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Arianna Calcinotto,
Paola Filipazzi,
Matteo Grioni,
Manuela Iero,
Angelo De Milito,
Alessia Ricupito,
Agata Cova,
Rossella Canese, Elena Jachetti,
Monica Rossetti,
Veronica Huber,
Giorgio Parmiani,
Luca Generoso,
Mario Santinami,
Martina Borghi,
Stefano Fais,
Matteo Bellone,
Licia Rivoltini
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ABSTRACT: Stimulating the effector functions of tumor-infiltrating T lymphocytes (TIL) in primary and metastatic tumors could improve active and adoptive T-cell therapies for cancer. Abnormal glycolysis, high lactic acid production, proton accumulation, and a reversed intra-extracellular pH gradient are thought to help render tumor microenvironments hostile to roving immune cells. However, there is little knowledge about how acidic microenvironments affect T-cell immunity. Here, we report that lowering the environmental pH to values that characterize tumor masses (pH 6-6.5) was sufficient to establish an anergic state in human and mouse tumor-specific CD8(+) T lymphocytes. This state was characterized by impairment of cytolytic activity and cytokine secretion, reduced expression of IL-2Rα (CD25) and T-cell receptors (TCR), and diminished activation of STAT5 and extracellular signal-regulated kinase (ERK) after TCR activation. In contrast, buffering pH at physiologic values completely restored all these metrics of T-cell function. Systemic treatment of B16-OVA-bearing mice with proton pump inhibitors (PPI) significantly increased the therapeutic efficacy of both active and adoptive immunotherapy. Our findings show that acidification of the tumor microenvironment acts as mechanism of immune escape. Furthermore, they illustrate the potential of PPIs to safely correct T-cell dysfunction and improve the efficacy of T-cell-based cancer treatments.
Cancer Research 05/2012; 72(11):2746-56. · 7.86 Impact Factor
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ABSTRACT: Abnormal tumor vasculature impairs T lymphocyte adhesion to endothelial cells and lymphocyte extravasation into neoplastic tissues, limiting the therapeutic potential of both active and adoptive immunotherapies. We have found that treatment of tumor-bearing mice with NGR-TNF, a Cys-Asn-Gly-Arg-Cys peptide-TNF fusion product capable of altering the endothelial barrier function and improving drug penetration in tumors, associated with the intratumor upregulation of leukocyte-endothelial cell adhesion molecules, the release of proinflammatory cytokines and chemokines, and the infiltration of tumor-specific effector CD8(+) T cells. As a result, NGR-TNF enhanced the therapeutic activity of adoptive and active immunotherapy, delaying tumor growth and prolonging survival. Furthermore, we have found that therapeutic effects of these combinations can be further increased by the addition of chemotherapy. Thus, these findings might be relevant for the design of novel immunotherapeutic approaches for cancer patients.
The Journal of Immunology 03/2012; 188(6):2687-94. · 5.79 Impact Factor
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ABSTRACT: Chronic inflammation, recruitment of myeloid-derived cells, and perturbation of the arginine metabolism have been all proposed as mechanisms favoring prostate carcinogenesis and tumor immunoescape. Objective of this study was to evaluate whether accumulation of CD11b(+)Gr1(+) cells, also defined myeloid-derived suppressor cells, occur in mice affected by transplantable or spontaneous prostate cancer (PC). We also investigated whether N(G) nitro-L-arginine methyl ester (L-NAME) and sildenafil, both modulators of the arginine metabolism, restrain tumor growth and restore tumor-specific immunity.
Wild-type C57BL/6 mice bearing TRAMP-C1 PC and transgenic adenocarcinoma of the mouse prostate (TRAMP) mice were treated with vehicle, L-NAME or sildenafil, and evaluated for CD11b(+) cells accumulation in the blood, several organs, and the tumor mass and for disease progression.
CD11b(+)Gr1(high), CD11b(+)Gr1(int), and CD11b(+)Gr1(-) cells differently accumulated in different organs and especially in the tumor of the two mouse models. L-NAME and sildenafil impaired the immunosuppressive function of CD11b(+) cells in both models and restrained TRAMP-C1 growth, but they neither break tumor-specific immune tolerance nor limit tumor progression in TRAMP mice.
Collectively, our results emphasize substantial differences in tumor-induced alteration of myelopoiesis and sensitivity to modulators of the arginine metabolism between a transplantable and a spontaneous model of PC. They also suggest that perturbation of the arginine metabolism is dispensable for PC progression and the associated T-cell tolerance.
Clinical Cancer Research 02/2011; 17(5):1012-23. · 7.74 Impact Factor
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Rodrigo Hess Michelini,
Massimo Freschi,
Teresa Manzo, Elena Jachetti,
Elena Degl'Innocenti,
Matteo Grioni,
Veronica Basso,
Chiara Bonini,
Elizabeth Simpson,
Anna Mondino,
Matteo Bellone
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ABSTRACT: Nonmyeloablative hematopoietic cell transplantation can cure patients with hematologic malignancies but has reported limited success against solid tumors. This is possibly because of profound peripheral tolerance mechanisms and/or suboptimal tumor recognition by effector T lymphocytes. We report that in mice developing spontaneous prostate cancer, nonmyeloablative minor histocompatibility mismatched hematopoietic stem cell transplantation, and donor lymphocyte infusion of unmanipulated lymphocytes combined with posttransplant tumor-specific vaccination circumvents tumor-specific tolerance, allowing acute tumor rejection and the establishment of protective immunosurveillance. Although donor-derived tumor-specific T cells readily differentiated into effector cells and infiltrated the tumor soon after infusion, they were alone insufficient for tumor eradication, which instead required the concomitance of minor histocompatibiltiy antigen-specific CD8(+) T-cell responses. The establishment of protective immunosurveillance was best induced by posttransplant tumor-specific vaccination. Hence, these results provide the proof of principle that tumor-specific T-cell responses have to be harnessed together with minor histocompatibility responses and sustained by posttransplant tumor-specific vaccination to improve the efficacy of allotransplantion for the cure of solid tumors.
Cancer Research 04/2010; 70(9):3505-14. · 7.86 Impact Factor
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ABSTRACT: CD1d-restricted invariant NKT (iNKT) cells are a subset of T lymphocytes endowed with innate effector functions that aid in the establishment of adaptive T and B cell immune responses. iNKT cells have been shown to play a spontaneous protective role against experimental tumors. Yet, the interplay between iNKT and tumor-specific T cells in cancer immune surveillance/editing has never been addressed. The transgenic adenocarcinoma of the mouse prostate (TRAMP) is a realistic model of spontaneous oncogenesis, in which the tumor-specific cytotoxic T cell (CTL) response undergoes full tolerance upon disease progression.
We report here that lack of iNKT cells in TRAMP mice resulted in the appearance of more precocious and aggressive tumors that significantly reduced animal survival. TRAMP mice bearing or lacking iNKT cells responded similarly to a tumor-specific vaccination and developed tolerance to a tumor-associated antigen at comparable rate.
Hence, our data argue for a critical role of iNKT cells in the immune surveillance of carcinoma that is independent of tumor-specific CTL.
PLoS ONE 01/2010; 5(1):e8646. · 4.09 Impact Factor
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ABSTRACT: Transgenic adenocarcinoma of the mouse prostate (TRAMP) mice spontaneously develop hormone-dependent and hormone-independent prostate cancer (PC) that potentially resembles the human pathological condition. The aim of the study was to validate PET imaging as a reliable tool for in vivo assessment of disease biology and progression in TRAMP mice using radioligands routinely applied in clinical practice: [(18)F]FDG and [(11)C]choline.
Six TRAMP mice were longitudinally evaluated starting at week 11 of age to visualize PC development and progression. The time frame and imaging pattern of PC lesions were subsequently confirmed on an additional group of five mice.
PET and [(18)F]FDG allowed detection of PC lesions starting from 23 weeks of age. [(11)C]Choline was clearly taken up only by TRAMP mice carrying neuroendocrine lesions, as revealed by post-mortem histological evaluation.
PET-based molecular imaging represents a state-of-the-art tool for the in vivo monitoring and metabolic characterization of PC development, progression and differentiation in the TRAMP model.
European Journal of Nuclear Medicine 04/2009; 36(8):1245-55. · 4.53 Impact Factor
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ABSTRACT: Targeted delivery of IFNgamma to tumors has been achieved by fusing this cytokine with GCNGRC, a tumor neovasculature homing peptide. Although the therapeutic efficacy of this protein (called IFNgamma-NGR) in animal models is greater than that of IFNgamma, frequent administrations of IFNgamma-NGR may result in lower efficacy and tumor resistance. We investigated the role of indoleamine 2,3-dioxygenase (IDO), an IFNgamma-inducible enzyme that may down-regulate T cells by affecting local tryptophan catabolism in tumor resistance to repeated treatments with IFNgamma-NGR. The study was carried out in immunocompetent mice and in nu/nu mice bearing RMA lymphoma, B16F melanoma, or WEHI-164 fibrosarcoma and in vitro using cultured tumor cells. IDO activity was increased in lymphoma homogenates after multiple treatments with IFNgamma-NGR but not after a single treatment. Coadministration of 1-methyl-tryptophan, an inhibitor of IDO, increased tumor responses to multiple treatments in the lymphoma, melanoma, and fibrosarcoma models. No synergism between IFNgamma-NGR and 1-methyl-tryptophan was observed in vitro in tumor cell proliferation assays or in nu/nu tumor-bearing mice, suggesting that the antitumor effect was host mediated. We conclude that IDO is critically involved in tumor resistance to repeated treatments with IFNgamma-NGR, likely causing excessive stimulation of tryptophan catabolism and inhibiting antitumor immune mechanisms. Coadministration of IFNgamma-NGR with IDO inhibitors could represent a new strategy for increasing its antitumor activity.
Molecular Cancer Therapeutics 01/2009; 7(12):3859-66. · 5.23 Impact Factor
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ABSTRACT: Poor penetration and uneven distribution of doxorubicin in tumors limits the efficacy of this drug in patients with prostate cancer (PC). Aim of the study was to investigate whether pre-treatment with NGR-TNF, a tumor necrosis factor-alpha derivative able to target tumor vessels and alter vessel permeability, increases the penetration and the efficacy of doxorubicin in pre-clinical models of PC.
Wild type C57BL/6 mice bearing androgen-independent TRAMP-C1 PC and transgenic adenocarcinoma of the mouse prostate (TRAMP) mice, which spontaneously develop PC and metastasis, were treated with repeated cycles of doxorubicin, administered either alone or following NGR-TNF. Tumor growth and drug uptake by cancer cells was evaluated.
Doxorubicin as a single agent blocked the growth of TRAMP-C1 cells in vitro but not in vivo. Pre-treatment of mice bearing subcutaneous TRAMP-C1 tumors with NGR-TNF favored doxorubicin penetration into the tumor mass, and in both TRAMP-C1 and TRAMP models significantly delayed tumor growth without increasing drug-related toxicity.
Pre-treatment with NGR-TNF significantly expanded the therapeutic index of doxorubicin in mouse models of hormone-dependent and -independent PC.
The Prostate 08/2008; 68(10):1105-15. · 3.48 Impact Factor
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ABSTRACT: CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) are thought to suppress the natural and vaccine-induced immune response against tumor-associated antigens (TAA). Here, we show that Treg accumulate in tumors and tumor-draining lymph nodes of aging transgenic adenocarcinoma of the mouse prostate (TRAMP) male mice, which spontaneously develop prostate cancer. TAA overexpression and disease progression associate also with induction of TAA-specific tolerance. TAA-specific T cells were found in the lymphoid organs of tumor-bearing mice. However, they had lost the ability to release IFN-gamma and kill relevant targets. Neither in vivo depletion of Treg by PC61 monoclonal antibody followed by repeated vaccinations with antigen-pulsed dendritic cells nor the combined treatment with 1-methyl-L-tryptophan inhibitor of the enzyme indoleamine 2,3-dyoxigenase, PC61 antibody, and dendritic cell vaccination restored the TAA-specific immune response. Treg did not seem to control the early phases of tolerance induction, as well. Indeed, depletion of Treg, starting at week 6, the age at which TRAMP mice are not yet tolerant, and prolonged up to week 12, did not avoid tolerance induction. A similar accumulation of Treg was found in the lymph nodes draining the site of dendritic cell vaccination both in TRAMP and wild-type animals. Hence, we conclude that Treg accrual is a phenomenon common to the sites of an ongoing immune response, and in TRAMP mice in particular, Treg are dispensable for induction of tumor-specific tolerance.
Cancer Research 02/2008; 68(1):292-300. · 7.86 Impact Factor
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ABSTRACT: Dendritic cell (DC) maturation influences the priming and polarization of T lymphocytes. We recently found that early activated DC (i.e. DC exposed to pro-maturation stimuli for 8 h) were more prone to prime in vivo a type-1 cytotoxic T cell (Tc1) response than DC exposed to pro-maturation stimuli for 48 h (48h-DC). We investigated whether 48h-DC, conversely, allowed the induction of Tc2 cells. Antigen-pulsed mouse bone-marrow-derived DC at any maturation stage, in the presence of exogenous IL-12, skewed in vitro naive CD8(+) T cells towards Tc1 cells, but 48h-DC most potently, in the presence of exogenous IL-4, favored the induction of Tc2 cells. In vivo, full maturation of DC promoted expansion of Tc2 and fall of Tc1 cells. Tc2 cells maintained a high cytolytic activity and produced significant amounts of IL-4, IL-5, IL-10 and TGF-beta. Our results indicate that polarization of naive CD8(+) T cells to Tc2 cells is dependent on the amount of time DC have been exposed to maturation stimuli, and might be favored in late and/or chronic phases of an immune response.
European Journal of Immunology 01/2007; 36(12):3157-66. · 5.10 Impact Factor
