Open Access
PD1 signal transduction pathways in T cells
(Impact Journals, 2017) Arasanz Esteban, Hugo; Gato Cañas, María; Zuazo Ibarra, Miren; Ibañez Vea, María; Breckpot, Karine; Kochan, Grazyna; Escors Murugarren, David; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua
The use of immune checkpoint inhibitors for the treatment of cancer is revolutionizing oncology. Amongst these therapeutic agents, antibodies that block PD-L1/PD1 interactions between cancer cells and T cells are demonstrating high efficacies and low toxicities. Despite all the recent advances, very little is yet known on the molecular intracellular signaling pathways regulated by either PD-L1 or PD1. Here we review the current knowledge on PD1-dependent intracellular signaling pathways, and the consequences of disrupting PD1 signal transduction.
Open Access
Profound reprogramming towards stemness in pancreatic cancer cells as adaptation to AKT inhibition
(MDPI, 2020) Arasanz Esteban, Hugo; Hernández, Carlos; Bocanegra Gondán, Ana Isabel; Chocarro de Erauso, Luisa; Zuazo Ibarra, Miren; Ciencias de la Salud; Osasun Zientziak; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua
Cancer cells acquire resistance to cytotoxic therapies targeting major survival pathways by adapting their metabolism. The AKT pathway is a major regulator of human pancreatic adenocarcinoma progression and a key pharmacological target. The mechanisms of adaptation to long-term silencing of AKT isoforms of human and mouse pancreatic adenocarcinoma cancer cells were studied. Following silencing, cancer cells remained quiescent for long periods of time, after which they recovered proliferative capacities. Adaptation caused profound proteomic changes largely affecting mitochondrial biogenesis, energy metabolism and acquisition of a number of distinct cancer stem cell (CSC) characteristics depending on the AKT isoform that was silenced. The adaptation to AKT1 silencing drove most de-differentiation and acquisition of stemness through C-MYC down-modulation and NANOG upregulation, which were required for survival of adapted CSCs. The changes associated to adaptation sensitized cancer cells to inhibitors targeting regulators of oxidative respiration and mitochondrial biogenesis. In vivo pharmacological co-inhibition of AKT and mitochondrial metabolism effectively controlled pancreatic adenocarcinoma growth in pre-clinical models.
Open Access
Understanding LAG-3 Signaling
(MDPI, 2021) Chocarro de Erauso, Luisa; Blanco, Ester; Zuazo Ibarra, Miren; Arasanz Esteban, Hugo; Bocanegra Gondán, Ana Isabel; Fernández Rubio, Leticia; Morente Sancho, Pilar; Fernández Hinojal, Gonzalo; Echaide Górriz, Míriam; Garnica, Maider; Ramos, Pablo; Vera García, Ruth; Kochan, Grazyna; Escors Murugarren, David; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua
Lymphocyte activation gene 3 (LAG-3) is a cell surface inhibitory receptor with multiple biological activities over T cell activation and effector functions. LAG-3 plays a regulatory role in immunity and emerged some time ago as an inhibitory immune checkpoint molecule comparable to PD-1 and CTLA-4 and a potential target for enhancing anti-cancer immune responses. LAG-3 is the third inhibitory receptor to be exploited in human anti-cancer immunotherapies, and it is considered a potential next-generation cancer immunotherapy target in human therapy, right next to PD-1 and CTLA-4. Unlike PD-1 and CTLA-4, the exact mechanisms of action of LAG-3 and its relationship with other immune checkpoint molecules remain poorly understood. This is partly caused by the presence of non-conventional signaling motifs in its intracellular domain that are different from other conventional immunoregulatory signaling motifs but with similar inhibitory activities. Here we summarize the current understanding of LAG-3 signaling and its role in LAG-3 functions, from its mechanisms of action to clinical applications.
Open Access
A proteomic atlas of lineage and cancer-polarized expression modules in myeloid cells modeling immunosuppressive tumor-infiltrating subsets
(MDPI, 2021) Blanco, Ester; Ibañez Vea, María; Hernández, Carlos; Drici, Lylia; Martínez de Morentin Iribarren, Xabier; Gato Cañas, María; Ausín, Karina; Bocanegra Gondán, Ana Isabel; Zuazo Ibarra, Miren; Chocarro de Erauso, Luisa; Arasanz Esteban, Hugo; Fernández Hinojal, Gonzalo; Fernández Irigoyen, Joaquín; Smerdou, Cristian; Garnica, Maider; Echaide Górriz, Míriam; Fernández Rubio, Leticia; Morente Sancho, Pilar; Ramos-Castellanos, Pablo; Llopiz, Diana; Santamaría Martínez, Enrique; Larsen, Martin R.; Escors Murugarren, David; Kochan, Grazyna; Osasun Zientziak; Institute for Multidisciplinary Research in Applied Biology - IMAB; Ciencias de la Salud; Gobierno de Navarra / Nafarroako Gobernua
Monocytic and granulocytic myeloid-derived suppressor cells together with tumor-infiltrating macrophages constitute the main tumor-infiltrating immunosuppressive myeloid populations. Due to the phenotypic resemblance to conventional myeloid cells, their identification and purification from within the tumors is technically difficult and makes their study a challenge. We differentiated myeloid cells modeling the three main tumor-infiltrating types together with uncommitted macrophages, using ex vivo differentiation methods resembling the tumor microenvironment. The phenotype and proteome of these cells was compared to identify linage-dependent relationships and cancer-specific interactome expression modules. The relationships between monocytic MDSCs and TAMs, monocytic MDSCs and granulocytic MDSCs, and hierarchical relationships of expression networks and transcription factors due to lineage and cancer polarization were mapped. Highly purified immunosuppressive myeloid cell populations that model tumor-infiltrating counterparts were systematically analyzed by quantitative proteomics. Full functional interactome maps have been generated to characterize at high resolution the relationships between the three main myeloid tumor-infiltrating cell types. Our data highlights the biological processes related to each cell type, and uncover novel shared and differential molecular targets. Moreover, the high numbers and fidelity of ex vivo-generated subsets to their natu-ral tumor-shaped counterparts enable their use for validation of new treatments in high-throughput experiments.
Open Access
Systemic blood immune cell populations as biomarkers for the outcome of immune checkpoint inhibitor therapies
(MDPI, 2020) Hernández, Carlos; Arasanz Esteban, Hugo; Chocarro de Erauso, Luisa; Bocanegra Gondán, Ana Isabel; Zuazo Ibarra, Miren; Ciencias de la Salud; Osasun Zientziak; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua
The development of cancer immunotherapy in the last decade has followed a vertiginous rhythm. Nowadays, immune checkpoint inhibitors (ICI) which include anti-CTLA4, anti-PD-1 and anti-PD-L1 antibodies are in clinical use for the treatment of numerous cancers. However, approximately only a third of the patients benefit from ICI therapies. Many efforts have been made for the identification of biomarkers allowing patient stratification into potential responders and progressors before the start of ICI therapies or for monitoring responses during treatment. While much attention is centered on biomarkers from the tumor microenvironment, in many cases biopsies are not available. The identification of systemic immune cell subsets that correlate with responses could provide promising biomarkers. Some of them have been reported to influence the response to ICI therapies, such as proliferation and activation status of CD8 and CD4 T cells, the expression of immune checkpoints in peripheral blood cells and the relative numbers of immunosuppressive cells such as regulatory T cells and myeloid-derived suppressor cells. In addition, the profile of soluble factors in plasma samples could be associated to response or tumor progression. Here we will review the cellular subsets associated to response or progression in different studies and discuss their accuracy in diagnosis.
Open Access
PD-L1 expression in systemic immune cell populations as a potential predictive biomarker of responses to PD-L1/PD-1 blockade therapy in lung cancer
(MDPI, 2019) Bocanegra Gondán, Ana Isabel; Fernández Hinojal, Gonzalo; Zuazo Ibarra, Miren; Arasanz Esteban, Hugo; García Granda, María Jesús; Hernández, Carlos; Ibañez Vea, María; Hernandez Marin, Berta; Martínez Aguillo, Maite; Lecumberri, María José; Fernández de Lascoiti, Ángela; Teijeira, Lucía; Morilla Ruiz, Idoia; Vera García, Ruth; Escors Murugarren, David; Kochan, Grazyna; Ciencias de la Salud; Osasun Zientziak; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
PD-L1 tumor expression is a widely used biomarker for patient stratification in PD-L1/PD-1 blockade anticancer therapies, particularly for lung cancer. However, the reliability of this marker is still under debate. Moreover, PD-L1 is widely expressed by many immune cell types, and little is known on the relevance of systemic PD-L1+ cells for responses to immune checkpoint blockade. We present two clinical cases of patients with non-small cell lung cancer (NSCLC) and PD-L1-negative tumors treated with atezolizumab that showed either objective responses or progression. These patients showed major differences in the distribution of PD-L1 expression within systemic immune cells. Based on these results, an exploratory study was carried out with 32 cases of NSCLC patients undergoing PD-L1/PD-1 blockade therapies, to compare PD-L1 expression profiles and their relationships with clinical outcomes. Significant differences in the percentage of PD-L1+ CD11b+ myeloid cell populations were found between objective responders and non-responders. Patients with percentages of PD-L1+ CD11b+ cells above 30% before the start of immunotherapy showed response rates of 50%, and 70% when combined with memory CD4 T cell profiling. These findings indicate that quantification of systemic PD-L1+ myeloid cell subsets could provide a simple biomarker for patient stratification, even if biopsies are scored as PD-L1 null
Open Access
Systemic CD4 immunity: a powerful clinical biomarker for PD-L1/PD-1 immunotherapy
(EMBO Press, 2020) Zuazo Ibarra, Miren; Arasanz Esteban, Hugo; Bocanegra Gondán, Ana Isabel; Chocarro de Erauso, Luisa; Vera García, Ruth; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua, BMED 050-2019
The search for non-invasive systemic biomarkers of response to PD-L1/PD-1 blockade immunotherapy is currently a priority in oncoimmunology. In contrast to classical tumor biomarkers, the identification of clinically useful immunological biomarkers is certainly a challenge, as anti-cancer immune responses depend on the coordinated action of many cell types. Studies on the dynamics of systemic CD8 T-cell populations have provided indications that such biomarkers may have a place in clinical practice. However, the power of CD8 T-cell subsets to discriminate clinical responses in immunotherapy has so far proven to be limited. The systemic evaluation of CD8 T-cell regulators such as myeloid cells and CD4 T cells may provide the solution. Here we discuss the value of systemic quantification of CD4 T-cell subsets for patient selection in light of the results obtained by Prof. Kagamu′s and our team. Our studies have independently demonstrated that the evaluation of the pre-treatment status of systemic CD4 immunity is a critical factor for the clinical outcome of PD-L1/PD-1 blockade therapy with robust predictive capacities.
Open Access
PD-1/LAG-3 co-signaling profiling uncovers CBL ubiquitin ligases as key immunotherapy targets
(EMBO Press, 2024-07-19) Chocarro de Erauso, Luisa; Blanco, Ester; Fernández-Rubio, Leticia; Garnica, Maider; Zuazo Ibarra, Miren; García Granda, María Jesús; Bocanegra Gondán, Ana Isabel; Echaide Górriz, Míriam; Johnston, Colette; Edwards, Carolyn J.; Legg, James; Pierce, Andrew J.; Arasanz Esteban, Hugo; Fernández Hinojal, Gonzalo; Vera García, Ruth; Ausín, Karina; Santamaría Martínez, Enrique; Fernández Irigoyen, Joaquín; Kochan, Grazyna; Escors Murugarren, David; Ciencias de la Salud; Osasun Zientziak
Many cancer patients do not benefit from PD-L1/PD-1 blockade immunotherapies. PD-1 and LAG-3 co-upregulation in T-cells is one of the major mechanisms of resistance by establishing a highly dysfunctional state in T-cells. To identify shared features associated to PD-1/LAG-3 dysfunctionality in human cancers and T-cells, multiomic expression profiles were obtained for all TCGA cancers immune infiltrates. A PD-1/LAG-3 dysfunctional signature was found which regulated immune, metabolic, genetic, and epigenetic pathways, but especially a reinforced negative regulation of the TCR signalosome. These results were validated in T-cell lines with constitutively active PD-1, LAG-3 pathways and their combination. A differential analysis of the proteome of PD-1/LAG-3 T-cells showed a specific enrichment in ubiquitin ligases participating in E3 ubiquitination pathways. PD-1/LAG-3 co-blockade inhibited CBL-B expression, while the use of a bispecific drug in clinical development also repressed C-CBL expression, which reverted T-cell dysfunctionality in lung cancer patients resistant to PD-L1/PD-1 blockade. The combination of CBL-B-specific small molecule inhibitors with anti-PD-1/anti-LAG-3 immunotherapies demonstrated notable therapeutic efficacy in models of lung cancer refractory to immunotherapies, overcoming PD-1/LAG-3 mediated resistance. © The Author(s) 2024.
Open Access
Early detection of hyperprogressive disease in non-small cell lung cancer by monitoring of systemic T cell dynamics
(MDPI, 2020) Arasanz Esteban, Hugo; Zuazo Ibarra, Miren; Bocanegra Gondán, Ana Isabel; Gato Cañas, María; Martínez Aguillo, Maite; Morilla Ruiz, Idoia; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Hyperprogressive disease (HPD) is an adverse outcome of immunotherapy consisting of an acceleration of tumor growth associated with prompt clinical deterioration. The definitions based on radiological evaluation present important technical limitations. No biomarkers have been identified yet. In this study, 70 metastatic NSCLC patients treated with anti-PD-1/PD-L1 immunotherapy after progression to platinum-based therapy were prospectively studied. Samples from peripheral blood were obtained before the first (baseline) and second cycles of treatment. Peripheral blood mononuclear cells (PBMCs) were isolated and differentiation stages of CD4 lymphocytes quantified by flow cytometry and correlated with HPD as identified with radiological criteria. A strong expansion of highly differentiated CD28− CD4 T lymphocytes (CD4 THD) between the first and second cycle of therapy was observed in HPD patients. After normalizing, the proportion of posttreatment/pretreatment CD4 THD was significantly higher in HPD when compared with the rest of patients (median 1.525 vs. 0.990; p = 0.0007), and also when stratifying by HPD, non-HPD progressors, and responders (1.525, 1.000 and 0.9700 respectively; p = 0.0025). A cutoff value of 1.3 identified HPD with 82% specificity and 70% sensitivity. An increase of CD28− CD4 T lymphocytes ≥ 1.3 (CD4 THD burst) was significantly associated with HPD (p = 0.008). The tumor growth ratio (TGR) was significantly higher in patients with expansion of CD4 THD burst compared to the rest of patients (median 2.67 vs. 0.86, p = 0.0049), and also when considering only progressors (median 2.67 vs. 1.03, p = 0.0126). A strong expansion of CD28− CD4 lymphocytes in peripheral blood within the first cycle of therapy is an early differential feature of HPD in NSCLC treated with immune-checkpoint inhibitors. The monitoring of T cell dynamics allows the early detection of this adverse outcome in clinical practice and complements radiological evaluation.
Open Access
PDL1 signals through conserved sequence motifs to overcome interferon-mediated cytotoxicity
(Elsevier, 2017) Gato Cañas, María; Zuazo Ibarra, Miren; Arasanz Esteban, Hugo; Ibañez Vea, María; Lorenzo, Laura; Fernández Hinojal, Gonzalo; Vera García, Ruth; Smerdou, Cristian; Martisova, Eva; Arozarena Martinicorena, Imanol; Wellbrock, Claudia; Llopiz, Diana; Ruiz, Marta; Sarobe, Pablo; Breckpot, Karine; Kochan, Grazyna; Escors Murugarren, David; Ciencias de la Salud; Osasun Zientziak; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua
PDL1 blockade produces remarkable clinical responses, thought to occur by T cell reactivation through prevention of PDL1-PD1 T cell inhibitory interactions. Here, we find that PDL1 cell-intrinsic signaling protects cancer cells from interferon (IFN) cytotoxicity and accelerates tumor progression. PDL1 inhibited IFN signal transduction through a conserved class of sequence motifs that mediate crosstalk with IFN signaling. Abrogation of PDL1 expression or antibody-mediated PDL1 blockade strongly sensitized cancer cells to IFN cytotoxicity through a STAT3/caspase-7-dependent pathway. Moreover, somatic mutations found in human carcinomas within these PDL1 sequence motifs disrupted motif regulation, resulting in PDL1 molecules with enhanced protective activities from type I and type II IFN cytotoxicity. Overall, our results reveal a mode of action of PDL1 in cancer cells as a first line of defense against IFN cytotoxicity.