Nuestros investigadores

Arantza Azpilicueta Lusarreta

Publicaciones científicas más recientes (desde 2010)

Autores: Otano Andrés, Itziar (Autor de correspondencia); Alvarez Rodriguez, Maite; Minute, L.; et al.
ISSN 1838-7640  Vol. 10  Nº 10  2020  págs. 4481 - 4489
Activation-induced cell death (AICD) is a complex immunoregulatory mechanism that causes the demise of a fraction of T-lymphocytes upon antigen-driven activation. In the present study we investigated the direct role of TNF in AICD of CD8 T lymphocytes. Methods: Human peripheral mononuclear cells were isolated from healthy donors and fresh tumor-infiltrating lymphocytes were obtained from cancer patients undergoing surgery. T cells were activated with anti-CD3/CD28 mAbs or with a pool of virus peptides, in combination with clinical-grade TNF blocking agents. Results: A portion of CD8 T cells undergoes apoptosis upon CD3/CD28 activation in a manner that is partially prevented by the clinically used anti-TNF agents infliximab and etanercept. TNF-mediated AICD was also observed upon activation of virus-specific CD8 T cells and tumor-infiltrating CD8 T lymphocytes. The mechanism of TNF-driven T cell death involves TNFR2 and production of mitochondrial oxygen free radicals which damage DNA. Conclusion: The use of TNF blocking agents reduces oxidative stress, hyperpolarization of mitochondria, and the generation of DNA damage in CD8 T celss undergoing activation. The fact that TNF mediates AICD in human tumor-reactive CD8 T cells suggests that the use of TNF-blocking agents can be exploited in immunotherapy strategies.
Autores: Teijeira Sánchez, Álvaro (Autor de correspondencia); Garasa, S.; Gato Cañas, María; et al.
ISSN 1074-7613  Vol. 52  Nº 5  2020  págs. 856 - 871.E8
Neutrophils are expanded and abundant in cancer-bearing hosts. Under the influence of CXCR1 and CXCR2 chemokine receptor agonists and other chemotactic factors produced by tumors, neutrophils, and granulocytic myeloid-derived suppressor cells (MDSCs) from cancer patients extrude their neutrophil extracellular traps (NETs). In our hands, CXCR1 and CXCR2 agonists proved to be the major mediators of cancer-promoted NETosis. NETs wrap and coat tumor cells and shield them from cytotoxicity, as mediated by CD8+ T cells and natural killer (NK) cells, by obstructing contact between immune cells and the surrounding target cells. Tumor cells protected from cytotoxicity by NETs underlie successful cancer metastases in mice and the immunotherapeutic synergy of protein arginine deiminase 4 (PAD4) inhibitors, which curtail NETosis with immune checkpoint inhibitors. Intravital microscopy provides evidence of neutrophil NETs interfering cytolytic cytotoxic T lymphocytes (CTLs) and NK cell contacts with tumor cells.
Autores: Minute, L. ; Teijeira Sánchez, Álvaro; Sanchez-Paulete, A. R. ; et al.
ISSN 2051-1426  Vol. 8  Nº 1  2020  págs. e000325
Background The immune response to cancer is often conceptualized with the cancer immunity cycle. An essential step in this interpretation is that antigens released by dying tumors are presented by dendritic cells to naive or memory T cells in the tumor-draining lymph nodes. Whether tumor cell death resulting from cytotoxicity, as mediated by T cells or natural killer (NK) lymphocytes, is actually immunogenic currently remains unknown. Methods In this study, tumor cells were killed by antigen-specific T-cell receptor (TCR) transgenic CD8 T cells or activated NK cells. Immunogenic cell death was studied analyzing the membrane exposure of calreticulin and the release of high mobility group box 1 (HMGB1) by the dying tumor cells. Furthermore, the potential immunogenicity of the tumor cell debris was evaluated in immunocompetent mice challenged with an unrelated tumor sharing only one tumor-associated antigen and by class I major histocompatibility complex (MHC)-multimer stainings. Mice deficient in Batf3, Ifnar1 and Sting1 were used to study mechanistic requirements. Results We observe in cocultures of tumor cells and effector cytotoxic cells, the presence of markers of immunogenic cell death such as calreticulin exposure and soluble HMGB1 protein. Ovalbumin (OVA)-transfected MC38 colon cancer cells, exogenously pulsed to present the gp100 epitope are killed in culture by mouse gp100-specific TCR transgenic CD8 T cells. Immunization of mice with the resulting destroyed cells induces epitope spreading as observed by detection of OVA-specific T cells by MHC multimer staining and rejection of OVA(+) EG7 lymphoma cells. Similar results were observed in mice immunized with cell debris generated by NK-cell mediated cytotoxicity. Mice deficient in Batf3-dependent dendritic cells (conventional dendritic cells type 1, cDC1) fail to develop an anti-OVA response when immunized with tumor cells killed by cytotoxic lymphocytes. In line with this, cultured cDC1 dendritic cells uptake and can readily cross-present antigen from cytotoxicity-killed tumor cells to cognate CD8(+) T lymphocytes. Conclusion These results support that an ongoing cytotoxic antitumor immune response can lead to immunogenic tumor cell death.
Autores: Rodríguez Ruiz, María Esperanza (Autor de correspondencia); Rodriguez, I.; Mayorga Ortiz, Lina Paola; et al.
ISSN 1535-7163  Vol. 18  Nº 3  2019  págs. 621 - 631
Radiotherapy can be synergistically combined with immunotherapy in mouse models, extending its efficacious effects outside of the irradiated field (abscopal effects). We previously reported that a regimen encompassing local radiotherapy in combination with anti-CD137 plus anti-PD-1 mAbs achieves potent abscopal effects against syngeneic transplanted murine tumors up to a certain tumor size. Knowing that TGF beta expression or activation increases in irradiated tissues, we tested whether TGF beta blockade may further enhance abscopal effects in conjunction with the anti-PD-1 plus anti-CD137 mAb combination. Indeed, TGF beta blockade with 1D11, a TGF beta-neutralizing mAb, markedly enhanced abscopal effects and overall treatment efficacy against subcutaneous tumors of either 4T1 breast cancer cells or large MC38 colorectal tumors. Increases in CD8 T cells infiltrating the nonirradiated lesion were documented upon combined treatment, which intensely expressed Granzyme-B as an indicator of cytotoxic effector capability. Interestingly, tumor tissue but not healthy tissue irradiation results in the presence of higher concentrations of TGF beta in the nonirradiated contralateral tumor that showed smad2/3 phosphorylation increases in infiltrating CD8 T cells. In conclusion, radiotherapy-induced TGF beta hampers abscopal efficacy even upon combination with a potent immunotherapy regimen. Therefore, TGF beta blockade in combination with radioimmunotherapy results in greater efficacy.
Autores: Etxeberria Uriz, Iñaki; Bolaños Mateo, Elixabet; Teijeira Sánchez, Álvaro; et al.
ISSN 0008-5472  Vol. 79  Nº 13  2019 
Autores: Aznar Gómez, María Ángela; Labiano Almiñana, Sara; Diaz-Lagares, A.; et al.
ISSN 2326-6066  Vol. 6  Nº 1  2018  págs. 69 - 78
CD137 (4-1BB) costimulation imprints long-term changes that instruct the ultimate behavior of T cells that have previously experienced CD137 ligation. Epigenetic changes could provide a suitable mechanism for these long-term consequences. Genome-wide DNA methylation arrays were carried out on human peripheral blood CD8(+) T lymphocytes stimulated with agonist monoclonal antibody to CD137, including urelumab, which is in phase I/II clinical trials for cancer immunotherapy. Several genes showed consistent methylation patterns in response to CD137 costimulation, which were confirmed by pyrosequencing in a series of healthy donors. CD96, HHLA2, CCR5, CXCR5, and CCL5 were among the immune-related genes regulated by differential DNA methylation, leading to changes in mRNA and protein expression. These genes are also differentially methylated in naive versus antigen-experienced CD8(+) T cells. The transcription factor TCF1 and the microRNA miR-21 were regulated by DNA methylation upon CD137 costimulation. Such gene-expression regulatory factors can, in turn, broaden the effects of DNA methylation by controlling expression of their target genes. Overall, chromatin remodeling is postulated to leave CD137-costimulated T lymphocytes poised to differentially respond upon subsequent antigen recognition. Accordingly, CD137 connects costimulation during priming to genome-wide DNA methylation and chromatin reprogramming. (C) 2017 AACR.
Autores: Azpilicueta Lusarreta, Arantza; Bolaños Mateo, Elixabet; Lang, V. ; et al.
ISSN 2162-402X  Vol. 7  Nº 1  2018  págs. e1368605
TRAF2 dependent K63-polyubiquitinations have been recently shown to connect CD137 (4-1BB) stimulation to NF kappa B activation. In a search of deubiquitinase enzymes (DUBs) that could regulate such a signaling route, A20 and CYLD were found to coimmunoprecipitate with CD137 and TRAF2 complexes. Indeed, overexpression of A20 or CYLD downregulated CD137-elicited ubiquitination of TRAF2 and TAK1 upon stimulation with agonist monoclonal antibodies. Moreover, overexpression of A20 or CYLD downregulated CD137-induced NF kappa B activation in cultured cells and in gene-transferred hepatocytes in vivo, while silencing these deubiquitinases enhanced CD137 costimulation of primary human CD8 T cells. Therefore A20 and CYLD directly downregulate the signaling from a T and NK-cell costimulatory receptor under exploitation for cancer immunotherapy in clinical trials.
Autores: Teijeira Sánchez, Álvaro; Labiano, S.; Garasa, S.; et al.
ISSN 2326-6066  Vol. 6  Nº 7  2018  págs. 798 - 811
T and NK lymphocytes express CD137 (4-1BB), a costimulatory receptor of the TNFR family whose function is exploitable for cancer immunotherapy. Mitochondria regulate the function and survival of F lymphocytes. herein, we show that CD137 costimulation provided by agonist mAb and CD137L (4-1BBL) induced mitochondria enlargement that resulted in enhanced mitochondrial mass and transmembrane potential in human and mouse CD8(+) T cells. Such mitochondrial changes increased 'T-cell respiratory capacities and were critically dependent on mitochondrial fusion protein OPA-1 expression. Mass and function of mitochondria in rumor-reactive CD8(+) T cells from cancer-hearing mice were invigorated by agonist mAb to CD137, whereas mitochondria) baseline mass and function were depressed in CD137-deficient tumor reactive T cells. Tumor rejection induced by the synergistic combination of adoptive T-cell therapy and agonistic anti-CD 137 WAS critically dependent on OPA-1 expression in transferred CD8(+) T cells. Moreover, stimulation of CD137 with CD137 mAb in shortterm cultures of human tumor-infiltrating lymphocytes led to mitochondria enlargement and increased transmembrane potential. Collectively, these data point to a critical link between mitochondrial morphology and function and enhanced antitumor effector activity upon CD 117 costimulation of T cells. (C)2018 AACR.
Autores: Sanchez-Paulete, A. R. ; Teijeira Sánchez, Álvaro; Quetglas, J. I.; et al.
ISSN 0008-5472  Vol. 78  Nº 23  2018  págs. 6643 - 6654
Multiple lines of evidence indicate a critical role of antigen cross-presentation by conventional BATF3-dependent type 1 classical dendritic cells (cDC1) in CD8-mediated antitumor immunity. Flt3L and XCL1, respectively, constitute a key growth/differentiation factor and a potent and specific chemoattractant for cDC1. To exploit their antitumor functions in local immunotherapy, we prepared Semliki Forest Virus (SFV)-based vectors encoding XCL1 and soluble Flt3L (sFlt3L). These vectors readily conferred transgene expression to the tumor cells in culture and when engrafted as subcutaneous mouse tumor models. In syngeneic mice, intratumoral injection of SFV-XCL1-sFlt3L (SFV-XF) delayed progression of MC38-and B16-derived tumors. Therapeutic activity was observed and exerted additive effects in combination with anti-PD-1, anti-CD137, or CTLA-4 immunostimulatory mAbs. Therapeutic effects were abolished by CD8 beta T-cell depletion and were enhanced by CD4 T-cell depletion, but not by T regulatory cell predepletion with anti-CD25 mAb. Antitumor effects were also abolished in BATF3- and IFNARdeficient mice. In B16-OVA tumors, SFV-XF increased the number of infiltratingCD8T cells, including those recognizing OVA. Consistently, following the intratumoral SFV-XF treatment courses, we observed increased BATF3-dependent cDC1 among B16-OVA tumor-infiltrating leukocytes. Such an intratumoral increase was not seen in MC38-derived tumors, but both resident and migratory cDC1 were boosted in SFV-XF-treated MC38 tumor-draining lymph nodes. In conclusion, viral gene transfer of sFlt3L and XCL1 is feasible, safe, and biologically active in mice, exerting antitumor effects that can be potentiated by CD4 T-cell depletion. Significance: These findings demonstrate that transgenic expression of sFLT3L and XCL1 in tumor cells mediates crosspriming of, and elicits potent antitumor activity from, CD8 T lymphocytes, particularly in combination with CD4 T-cell depletion. (C) 2018 AACR.
Autores: Perez-Ruiz, E.; Minute, L.; Ochoa Nieto, Maria del Carmen; et al.
ISSN 0008-5472  Vol. 78  Nº 13 Supl.  2018 
Autores: Alfaro Alegría, Carlos; Teijeira Sánchez, Álvaro; Oñate Salafranca, Carmen; et al.
ISSN 1078-0432  Vol. 22  Nº 15  2016  págs. 3924 - 3936
PURPOSE: Myeloid-derived suppressor cells (MDSC) are considered an important T-cell immunosuppressive component in cancer-bearing hosts. The factors that attract these cells to the tumor microenvironment are poorly understood. IL8 (CXCL8) is a potent chemotactic factor for neutrophils and monocytes. EXPERIMENTAL DESIGN: MDSC were characterized and sorted by multicolor flow cytometry on ficoll-gradient isolated blood leucokytes from healthy volunteers (n = 10) and advanced cancer patients (n = 28). In chemotaxis assays, sorted granulocytic and monocytic MDSC were tested in response to recombinant IL8, IL8 derived from cancer cell lines, and patient sera. Neutrophil extracellular traps (NETs) formation was assessed by confocal microscopy, fluorimetry, and time-lapse fluorescence confocal microscopy on short-term MDSC cultures. RESULTS: IL8 chemoattracts both granulocytic (GrMDSC) and monocytic (MoMDSC) human MDSC. Monocytic but not granulocytic MDSC exerted a suppressor activity on the proliferation of autologous T cells isolated from the circulation of cancer patients. IL8 did not modify the T-cell suppressor activity of human MDSC. However, IL8 induced the formation of NETs in the GrMDSC subset. CONCLUSIONS: IL8 derived from tumors contributes to the chemotactic recruitment of MDSC and to their functional control.
Autores: Labiano Almiñana, Sara; Palazón García, Francisco de Asís; Bolaños Mateo, Elixabet; et al.
ISSN 2162-4011  Vol. 5  Nº 1  2015  págs. e1062967
Hypoxia is a common feature in solid tumors that has been implicated in immune evasion. Previous studies from our group have shown that hypoxia upregulates the co-stimulatory receptor CD137 on activated T lymphocytes and on vascular endothelial cells. In this study, we show that exposure of mouse and human tumor cell lines to hypoxic conditions (1% O2) promotes CD137 transcription. However, the resulting mRNA is predominantly an alternatively spliced form that encodes for a soluble variant, lacking the transmembrane domain. Accordingly, soluble CD137 (sCD137) is detectable by ELISA in the supernatant of hypoxia-exposed cell lines and in the serum of tumor-bearing mice. sCD137, as secreted by tumor cells, is able to bind to CD137-Ligand (CD137L). Our studies on primed T lymphocytes in co-culture with stable transfectants for CD137L demonstrate that tumor-secreted sCD137 prevents co-stimulation of T lymphocytes. Such an effect results from preventing the interaction of CD137L with the transmembrane forms of CD137 expressed on T lymphocytes undergoing activation. Indeed, silencing CD137 with shRNA renders more immunogenic tumor-cell variants upon inoculation to immunocompetent mice but which readily grafted on immunodeficient or CD8+ T-cell-depleted mice. These mechanisms are interpreted as a molecular strategy deployed by tumors to repress lymphocyte co-stimulation via CD137/CD137L.
Autores: Paiva, Bruno (Autor de correspondencia); Azpilicueta Lusarreta, Arantza; Puig, N.; et al.
ISSN 0887-6924  Vol. 29  Nº 10  2015  págs. 2110 - 2113
Autores: Unzu Ezquerro, Carmen María; Melero Bermejo, Ignacio; Morales Kastresana, Aizea; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 9  Nº 1  2014  págs. e85432
The immune system poses obstacles to viral vectors, even in the first administration to preimmunized hosts. We have observed that the livers of B cell-deficient mice were more effectively transduced by a helper-dependent adenovirus serotype-5 (HDA) vector than those of WT mice. This effect was T-cell independent as shown in athymic mice. Passive transfer of the serum from adenovirus-naive WT to Rag1KO mice resulted in a reduction in gene transfer that was traced to IgM purified from serum of adenovirus-naive mice. To ascribe the gene transfer inhibition activity to either adenoviral antigen-specific or antigen-unspecific functions of IgM, we used a monoclonal IgM antibody of unrelated specificity. Both the polyclonal and the irrelevant monoclonal IgM inhibited gene transfer by the HDA vector to either cultured hepatocellular carcinoma cells or to the liver of mice in vivo. Adsorption of polyclonal or monoclonal IgMs to viral capsids was revealed by ELISAs on adenovirus-coated plates. These observations indicate the existence of an inborn IgM mechanism deployed against a prevalent virus to reduce early post-infection viremia. In conclusion, innate IgM binding to adenovirus serotype-5 capsids restrains gene-transfer and offers a mechanism to be targeted for optimization of vector dosage in gene therapy with HDA vectors.
Autores: Martínez Forero, Ivan Efrain; Azpilicueta Lusarreta, Arantza; Bolaños Mateo, Elixabet; et al.
ISSN 0022-1767  Vol. 190  Nº 12  2013  págs. 6694 - 6706
Agonist anti-CD137 (4-1BB) mAbs enhance CD8-mediated antitumor immunity. Agonist anti-human CD137 mAbs binding to four distinct epitopes on the CD137 glycoprotein costimulated T cell activation irrespective of the engaged epitope or its interference with CD137L binding. CD137 perturbation with all these agonist mAbs resulted in Ag and Ab internalization toward an endosomal vesicular compartment. Internalization was observed in activated T lymphocytes from humans and mice, not only in culture but also in Ab-injected living animals. These in vivo experiments were carried out upon systemic i.v. injections with anti-CD137 mAbs and showed CD137 internalization in tumor-infiltrating lymphocytes and in activated human T cells transferred to immunodeficient mice. Efficient CD137 internalization required K63 polyubiquitination and endocytosed CD137-containing vesicles recruited TNFR-associated factor (TRAF) 2 and were decorated with K63 polyubiquitins. CD137 stimulation activates NF-¿B through a K63-linked polyubiquitination-dependent route, and CD137-associated TRAF2 becomes K63 polyubiquitinated. Consistent with a role for TRAF2 in CD137 signaling, transgenic mice functionally deficient in TRAF2 showed delayed immunotherapeutic activity of anti-CD137 mAbs. As a whole, these findings advance our knowledge of the mechanisms of action of anti-CD137 immunostimulatory mAbs such as those currently undergoing clinical trials in cancer patients.
Autores: Morales-Kastresana, A.; Catalán, E.; Hervas Stubbs, Sandra; et al.
ISSN 2051-1426  Vol. 1  2013  págs. 3
BACKGROUND: Treatment with agonist anti-CD137 (4-1BB) immunostimulatory monoclonal antibodies elicits complete tumor regressions in a number of transplanted hematological and solid malignancies in mice. Rejection is mainly dependent on cytotoxic T lymphocytes (CTL) and IFN¿, although a role for NK cells and dendritic cells has been observed in some tumor models. Rejection of EG7-derived thymomas has been shown to be CTL-dependent but not NK-dependent. FINDINGS: In this therapeutic setting, we show that both the perforin-granzyme and FasL effector systems are readily expressed by CD8(+) T lymphocytes infiltrating the EG7 lymphomas which are undergoing rejection. Using knock-out mice, we demonstrate that both effector cytolytic systems are involved in the execution of complete immune rejections against EG7 established tumors. In accordance, EG7 tumor cells were susceptible in vitro to both killing mechanisms acting in a synergistic fashion. CONCLUSIONS: CD137-elicited rejection of EG7-derived tumors involves the interplay of at least two final effector cytolytic mechanisms that act in cooperation.
Autores: Teijeira Sánchez, Álvaro; Garasa, S.; Pelaez Cristobal, Rafael; et al.
ISSN 1523-1747  Vol. 133  Nº 9  2013  págs. 2276 - 2285
Dendritic cell (DC) transmigration across the lymphatic endothelium is critical for the initiation and sustenance of immune responses. Under noninflammatory conditions, DC transit across the lymphatic endothelial cell (LEC) has been shown to be integrin independent. In contrast, there is increasing evidence for the participation of integrins and their ligands in DC transit across lymphatic endothelium under inflammation. In this sense, we describe the formation of ICAM-1 (CD54)-enriched three-dimensional structures on LEC/DC contacts, as these DCs adhere to inflamed skin lymphatic vessels and transmigrate into them. In vitro imaging revealed that under inflammation ICAM-1 accumulated on microvilli projections surrounding 60% of adhered DCs. In contrast, these structures were scarcely formed in noninflammatory conditions. Furthermore, ICAM-1-enriched microvilli were important in promoting DC transendothelial migration and DC crawling over the LEC surface. Microvilli formation was dependent on the presence of beta-integrins on the DC side and on integrin conformational affinity to ligand. Finally, we observed that LEC microvilli structures appeared in close vicinity of CCL21 depots and that their assembly was partially inhibited by CCL21-neutralizing antibodies. Therefore, under inflammatory conditions, integrin ligands form three-dimensional membrane projections around DCs. These structures offer docking sites for DC transit from the tissue toward the lymphatic vessel lumen.
Autores: Morales Kastresana, Aizea; Fernández de Sanmamed Gutiérrez, Miguel; Rodríguez, I.; et al.
ISSN 1078-0432  Vol. 19  Nº 22  2013  págs. 6151 - 6162
Purpose: Immunostimulatory monoclonal antibodies (ISmAb) that unleash antitumor immune responses are showing efficacy in cancer clinical trials. Anti-B7-H1 (PD-L1) monoclonal antibodies (mAb) block a critical inhibitory pathway in T cells, whereas anti-CD137 and OX40 mAbs provide T-cell costimulation. A combination of these ISmAbs (anti-CD137 + anti-OX40 + anti-B7-H1) was tested using a transgenic mouse model of multifocal and rapidly progressing hepatocellular carcinoma, in which c-myc drives transformation and cytosolic ovalbumin (OVA) is expressed in tumor cells as a model antigen. Experimental Design: Flow-cytometry and immunohistochemistry were used to quantify tumor-infiltrating lymphocytes (TIL) elicited by treatment and assess their activation status and cytolytic potential. Tolerance induction and its prevention/reversal by treatment with the combination of ISmAbs were revealed by in vivo killing assays. Results: The triple combination of ISmAbs extended survival of mice bearing hepatocellular carcinomas in a CD8-dependent fashion and synergized with adoptive T-cell therapy using activated OVA-specific TCR-transgenic OT-1 and OT-2 lymphocytes. Mice undergoing therapy showed clear increases in tumor infiltration by activated and blastic CD8(+) and CD4(+) T lymphocytes containing perforin/granzyme B and expressing the ISmAb-targeted receptors on their surface. The triple combination of ISmAbs did not result in enhanced OVA-specific cytotoxic T lymphocyte (CTL) activity but other antigens expressed by cell lines derived from such hepatocellular carcinomas were recognized by endogenous TILs. Adoptively transferred OVA-specific OT-1 lymphocytes into tumor-bearing mice were rendered tolerant, unless given the triple mAb therapy. Conclusion: Extension of survival and dense T-cell infiltrates emphasize the translational potential of combinational immunotherapy strategies for hepatocellular carcinoma.
Autores: Dubrot Armendáriz, Juan; Palazón García, Francisco de Asís; Alfaro Alegría, Carlos; et al.
Revista: International Journal of Cancer (Print)
ISSN 0020-7136  Vol. 28  Nº 1  2011  págs. 105 - 118
Autores: Hervas Stubbs, Sandra; Riezu Boj, José Ignacio; González, I; et al.
Revista: European Journal of Immunology
ISSN 0014-2980  Vol. 40  Nº 12  2010  págs. 3389 - 3402