Nuestros investigadores

Aintzane Zabaleta Azpiroz

Publicaciones científicas más recientes (desde 2010)

Autores: Ochoa, María del Carmen; Perez-Ruiz, E.; Minute, L. ; et al.
Revista: ONCOIMMUNOLOGY
ISSN 2162-402X  Vol. 8  Nº 7  2019  págs. 1599636
Daratumumab is an anti-CD38 fully human IgG1 mAb approved for multiple myeloma treatment. One of the proposed mechanisms of action is the induction of antibody-dependent cellular cytotoxicity (ADCC) mediated by NK cells. NK cells acquire surface CD137 expression in the presence of solid-phase-attached daratumumab and when encountering a daratumumab-coated CD38(+) tumor cell line. In this setting, addition of the agonist anti-CD137 mAb urelumab enhances NK-cell activation increasing CD25 expression and IFN gamma production. However, in vitro ADCC is not increased by the addition of urelumab both in 4h or 24h lasting experiments. To study urelumab-increased daratumumab-mediated ADCC activity in vivo, we set up a mouse model based on the intravenous administration of a luciferase-transfected multiple myeloma cell line of human origin, human NK cells and daratumumab to immuno-deficient NSG mice. In this model, intravenous administration of urelumab 24h after daratumumab delayed tumor growth and prolonged mice survival.
Autores: Moreno, Laura; Zabaleta, Aintzane; et al.
Revista: CLINICAL CANCER RESEARCH
ISSN 1078-0432  Vol. 25  Nº 10  2019  págs. 3176 - 3187
Purpose: Knowledge about the mechanism of action (MoA) of monoclonal antibodies (mAb) is required to understand which patients with multiple myeloma (MM) benefit the most from a given mAb, alone or in combination therapy. Although there is considerable research about daratumumab, knowledge about other anti-CD38 mAbs remains scarce. Experimental Design: We performed a comprehensive analysis of the MoA of isatuximab. Results: Isatuximab induces internalization of CD38 but not its significant release from MMcell surface. In addition, we uncovered an association between levels of CD38 expression and different MoA: (i) Isatuximab was unable to induce direct apoptosis on MM cells with CD38 levels closer to those in patients with MM, (ii) isatuximab sensitized CD38(hi) MMcells to bortezomib plus dexamethasone in the presence of stroma, (iii) antibody-dependent cellular cytotoxicity (ADCC) was triggered by CD38(lo) and CD38(hi) tumor plasma cells (PC), (iv) antibody-dependent cellular phagocytosis (ADCP) was triggered only by CD38(hi) MM cells, whereas (v) complement-dependent cytotoxicity could be triggered in less than half of the patient samples (those with elevated levels of CD38). Furthermore, we showed that isatuximab depletes CD38(hi) B-lymphocyte precursors and natural killer (NK) lymphocytes ex vivo-the latter through activation followed by exhaustion and eventually phagocytosis. Conclusions: This study provides a framework to understand response determinants in patients treated with isatuximab based on the number of MoA triggered by CD38 levels of expression, and for the design of effective combinations aimed at capitalizing disrupted tumor-stroma cell protection, augmenting NK lymphocyte-mediated ADCC, or facilitating ADCP in CD38(lo) MM patients.
Autores: Marcos-Jubilar, María; Orbe, J; Roncal, Carmen; et al.
Revista: CLINICA E INVESTIGACION EN ARTERIOSCLEROSIS
ISSN 0214-9168  Vol. 31  Nº 4  2019  págs. 152 - 159
Introduction: Monocytes play an important role in atherosclerotic progression having both pro and anti-inflammatory effects depending on different circulating monocyte subpopulations. The objective of this study is to characterize these subpopulations and their association with cardiovascular risk factors. Methods: Transversal study including 102 selected patients, mean age: 65 years-old (range 41-86), 69% males. A set of specific antibodies against classical monocytes (Mont, CD14+CD16- CD300e+HLADR+), intermediate (Mon2, CD14+CD16+CD300e+HLADR+) and nonclassical (Mon3, CD14 CD16+CD300e+HLADR+) was assayed. Three groups of patients were included: 17 asymptomatic with more than one cardiovascular risk factor (group 1), 56 subjects asymptomatic but with vascular pathology assessed by ultrasound or microalbuminuria (group 2) and 19 patients with a previous atherothrombotic event (group 3). The cardiovascular risk was determined by Framingham and REGICOR scores. Results: An association between study groups and the percentage of Mon1 and Mon2 was observed (ANOVA, p <.05), being independent of age and sex for Mon2. Likewise Mont and Mon2 subpopulations were associated with cardiovascular adverse events (beta=0.86, p=.02 beta-0.1 p=.002, respectively), independently of age and sex in the case of Mon2. Moreover the percentage of Mon3 was associated with the presence of several cardiovascular risk factors ((3 = 0.21, p =.04) in the univariate analysis. In addition, there was a correlation between the levels of Mon1 and Mon2 and leukocytes (r =0.7, p <.001 and r =0.26, p =.01, respectively). Conclusions: The analysis of monocyte subpopulations may be clinically useful to stratify the inflammatory profile related to the different cardiovascular risk groups.
Autores: Zabaleta, Aintzane; Sangro, Paloma; et al.
Revista: TRANSPLANTATION PROCEEDINGS
ISSN 0041-1345  Vol. 51  Nº 1  2019  págs. 77 - 79
Autores: Botta, C.; Zabaleta, Aintzane; et al.
Revista: HAEMATOLOGICA
ISSN 0390-6078  Vol. 104  2019  págs. 149 - 149
Autores: Ruiz, C. P.; Zabaleta, Aintzane; Puig, N.; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 132  Nº Supl. 1  2018 
Autores: Seckinger A; Delgado, JA; Moser S; et al.
Revista: CANCER CELL
ISSN 1535-6108  Vol. 31  Nº 3  2017  págs. 396 - 410
We identified B cell maturation antigen (BCMA) as a potential therapeutic target in 778 newly diagnosed and relapsed myeloma patients. We constructed an IgG-based BCMA-T cell bispecific antibody (EM801) and showed that it increased CD3(+) T cell/myeloma cell crosslinking, followed by CD4(+)/CD8(+) T cell activation, and secretion of interferon-gamma, granzyme B, and perforin. This effect is CD4 and CD8 T cell mediated. EM801 induced, at nanomolar concentrations, myeloma cell death by autologous T cells in 34 of 43 bone marrow aspirates, including those from high-risk patients and patients after multiple lines of treatment, tumor regression in six of nine mice in a myeloma xenograft model, and depletion of BCMA(+) cells in cynomolgus monkeys. Pharmacokinetics and pharmacodynamics indicate weekly intravenous/subcutaneous administration.
Autores: Zabaleta, Aintzane; Riezu-Boj, José Ignacio; Larrea, Esther; et al.
Revista: JOURNAL OF MEDICAL VIROLOGY
ISSN 0146-6615  Vol. 88  Nº 5  2016  págs. 843 - 851
Viral clearance during acute hepatitis C virus (HCV) infection is associated with the induction of potent antiviral T-cell responses. Since dendritic cells (DC) are essential in the activation of primary T-cell responses, gene expression was analyzed in DC from patients during acute HCV infection. By using microarrays, gene expression was compared in resting and activated peripheral blood plasmacytoid (pDC) and myeloid (mDC) DC from acute HCV resolving patients (AR) and from patients who become chronically infected (ANR), as well as in healthy individuals (CTRL) and chronically-infected patients (CHR). For pDC, a high number of upregulated genes was found in AR patients, irrespective of DC stimulation. However, for mDC, most evident differences were detected after DC stimulation, again corresponding to upregulated genes in AR patients. Divergent behavior of ANR was also observed when analyzing DC from CTRL and CHR, with ANR patients clustering again apart from these groups. These differences corresponded to metabolism-associated genes and genes belonging to pathways relevant for DC activation and cytokine responses. Thus, upregulation of relevant genes in DC during acute HCV infection may determine viral clearance, suggesting that dysfunctional DC may be responsible for the lack of efficient T-cell responses which lead to chronic HCV infection.
Autores: Moreno, L.; Zabaleta, Aintzane; et al.
Revista: BLOOD
ISSN 0006-4971  Vol. 128  Nº 22  2016 
Autores: Zabaleta, Aintzane; D'Avola, Delia; Llopiz, Diana Isabel; et al.
Revista: MOLECULAR THERAPY. METHODS & CLINICAL DEVELOPMENT
ISSN 2329-0501  Vol. 2  2015  págs. 15006
The lack of antiviral cellular immune responses in patients with chronic hepatitis C virus (HCV) infection suggests that T-cell vaccines may provide therapeutic benefit. Due to the central role that dendritic cells (DC) play in the activation of T-cell responses, our aim was to carry out a therapeutic vaccination clinical trial in HCV patients using DC. Five patients with chronic HCV infection were vaccinated with three doses of 5¿×¿10(6) or 10(7) autologous DC transduced with a recombinant adenovirus encoding NS3 using the adapter protein CFh40L, which facilitates DC transduction and maturation. No significant adverse effects were recorded after vaccination. Treatment caused no changes in serum liver enzymes nor in viral load. Vaccination induced weak but consistent expansion of T-cell responses against NS3 and adenoviral antigens. Patients' DC, as opposed to murine DC or DC from healthy subjects, secreted high IL-10 levels after transduction, inducing the activation of IL-10-producing T cells. IL-10 blockade during vaccine preparation restored its ability to stimulate anti-NS3 Th1 responses. Thus, vaccination with adenovirus-transduced DC is safe and induces weak antiviral immune responses. IL-10 associated with vaccine preparation may be partly responsible for these effects, suggesting that future vaccines should consider concomitant inhibition of this cytokine
Autores: Llopiz, Diana Isabel; Ruiz, Marta; Bezunartea, J.; et al.
Revista: ONCOIMMUNOLOGY
ISSN 2162-402X  Vol. 2  Nº 12  2013  págs. UNSP e27009
Peptide vaccines derived from CD8(+) T-cell epitopes have shown variable efficacy in cancer patients. Thus, some peptide vaccines are capable of activating CD8(+) T-cell responses, even in the absence of CD4(+) T-cell epitopes or dendritic cell (DC)-activating adjuvants. However, the mechanisms underlying the clinical activity of these potent peptides are poorly understood. Using CT26 and ovalbumin-expressing B16 murine allograft tumor models, we found that the antitumor effect of helper cell-independent CD8 T-cell peptide vaccines is inhibited by the blockade of CD40 ligand (CD40L) in vivo. Furthermore, in vitro stimulation with antigenic peptides of cells derived from immunized mice induced the expression of CD40L on the surface of CD8(+) T cells and fostered DC maturation, an effect that was partially inhibited by CD40L-blocking antibodies. Interestingly, CD40L blockade also inhibited CD8(+) T-cell responses, even in the presence of fully mature DCs, suggesting a role for CD40L not only in promoting DC maturation but also in mediating CD8(+) T-cell co-stimulation. Importantly, these potent peptides share features with bona fide CD4 epitopes, since they foster responses against less immunogenic CD8(+) T-cell epitopes in a CD40L-dependent manner. The analysis of peptides used for the vaccination of cancer patients in clinical trials showed that these peptides also induce the expression of CD40L on the surface of CD8(+) T cells. Taken together, these results suggest that CD40L expression induced by potent CD8(+) T-cell epitopes can activate antitumor CD8(+) T-cell responses, potentially amplifying the immunological responses to less immunogenic CD8(+) T-cell epitopes and bypassing the requirement for CD4(+) helper T cells in vaccination protocols.
Autores: Pereboev, A; Zabaleta, Aintzane; et al.
Revista: HEPATOLOGY
ISSN 0270-9139  Vol. 1  Nº 54  2011  págs. 28 - 37