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
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
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
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
TNF-α-secreting tumor-infiltrated monocytes play a pivotal role during anti-PD-L1 immunotherapy
(Frontiers Media, 2022) Zuazo Ibarra, Miren; Ridder, Kirsten de; Locy, Hanne; Piccioni, Elisa; Awad, Robin Maximilian; Verhulst, Stefaan; Van Bulck, Mathias; Vlaeminck, Yannick de; Lecoq, Quentin; Reijimen, Eva; Mey, Wout de; Beck, Lien de; Ertveldt, Thomas; Pintelon, Isabel; Timmermans, Jean-Pierre; Escors Murugarren, David; Keyaerts, Marleen; Breckpot, Karine; Goyvaerts, Cleo; Ciencias de la Salud; Osasun Zientziak; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua
Immune checkpoint blockade (ICB) of the PD-1 pathway revolutionized the survival forecast for advanced non-small cell lung cancer (NSCLC). Yet, the majority of PD-L1+ NSCLC patients are refractory to anti-PD-L1 therapy. Recent observations indicate a pivotal role for the PD-L1+ tumor-infiltrating myeloid cells in therapy failure. As the latter comprise a heterogenous population in the lung tumor microenvironment, we applied an orthotopic Lewis Lung Carcinoma (LLC) model to evaluate 11 different tumor-residing myeloid subsets in response to anti-PD-L1 therapy. While we observed significantly reduced fractions of tumor-infiltrating MHC-IIlow macrophages and monocytes, serological levels of TNF-a restored in lung tumor-bearing mice. Notably, we demonstrated in vivo and in vitro that anti-PD-L1 therapy mediated a monocytespecific production of, and response to TNF-a, further accompanied by their significant upregulation of CD80, VISTA, LAG-3, SIRP-a and TIM-3. Nevertheless, co-blockade of PD-L1 and TNF-a did not reduce LLC tumor growth. A phenomenon that was partly explained by the observation that monocytes and TNF-a play a Janus-faced role in anti-PD-L1 therapy-mediated CTL stimulation. This was endorsed by the observation that monocytes appeared crucial to effectively boost T cell-mediated LLC killing in vitro upon combined PD-L1 with LAG-3 or SIRP-a blockade. Hence, this study enlightens the biomarker potential of lung tumor-infiltrated monocytes to define more effective ICB combination strategies.
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
The multi-specific VH-based Humabody CB213 co-targets PD1 and LAG3 on T cells to promote anti-tumour activity
(Springer Nature, 2021) Edwards, Carolyn J.; Sette, Angelica; Cox, Carl; Di Fiore, Barabara; Wyre, Chris; Sydoruk, Daniela; Yadin, David; Hayes, Philip; Stelter, Szymon; Bartlett, Phillip D.; Zuazo Ibarra, Miren; García Granda, María Jesús; Benedetti, Giovanni; Fiaska, Stratonik; Birkett, Neil R.; Teng, Yumin; Enever, Carrie; Arasanz Esteban, Hugo; Bocanegra Gondán, Ana Isabel; Chocarro de Erauso, Luisa; Fernández Hinojal, Gonzalo; Vera García, Ruth; Archer, Bethan; Osuch, Isabelle; Lewandowska, Martyna; Surani, Yasmin M.; Kochan, Grazyna; Escors Murugarren, David; Legg, James; Pierce, Andrew J.; Ciencias de la Salud; Osasun Zientziak; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa; Gobierno de Navarra / Nafarroako Gobernua
Background: improving cancer immunotherapy long-term clinical benefit is a major priority. It has become apparent that multiple axes of immune suppression restrain the capacity of T cells to provide anti-tumour activity including signalling through PD1/PD-L1 and LAG3/MHC-II. Methods: CB213 has been developed as a fully human PD1/LAG3 co-targeting multi-specific Humabody composed of linked VH domains that avidly bind and block PD1 and LAG3 on dual-positive T cells. We present the preclinical primary pharmacology of CB213: biochemistry, cell-based function vs. immune-suppressive targets, induction of T cell proliferation ex vivo using blood obtained from NSCLC patients, and syngeneic mouse model anti-tumour activity. CB213 pharmacokinetics was assessed in cynomolgus macaques. Results: CB213 shows picomolar avidity when simultaneously engaging PD1 and LAG3. Assessing LAG3/MHC-II or PD1/PD-L1 suppression individually, CB213 preferentially counters the LAG3 axis. CB213 showed superior activity vs. αPD1 antibody to induce ex vivo NSCLC patient T cell proliferation and to suppress tumour growth in a syngeneic mouse tumour model, for which both experimental systems possess PD1 and LAG3 suppressive components. Non-human primate PK of CB213 suggests weekly clinical administration. Conclusions: CB213 is poised to enter clinical development and, through intercepting both PD1 and LAG3 resistance mechanisms, may benefit patients with tumours escaping front-line immunological control.
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.
Open Access
Molecular mechanisms of programmed cell death-1 dependent T cell suppression: relevance for immunotherapy
(AME Publishing, 2017) Zuazo Ibarra, Miren; Gato Cañas, María; Llorente, Noelia; Ibañez Vea, María; Arasanz Esteban, Hugo; Kochan, Grazyna; Escors Murugarren, David; Ciencias de la Salud; Osasun Zientziak; Gobierno de Navarra / Nafarroako Gobernua
Programmed cell death-1 (PD1) has become a significant target for cancer immunotherapy. PD1 and its receptor programmed cell death 1 ligand 1 (PDL1) are key regulatory physiological immune checkpoints that maintain self-tolerance in the organism by regulating the degree of activation of T and B cells amongst other immune cell types. However, cancer cells take advantage of these immunosuppressive regulatory mechanisms to escape T and B cell-mediated immunity. PD1 engagement on T cells by PDL1 on the surface of cancer cells dramatically interferes with T cell activation and the acquisition of effector capacities. Interestingly, PD1-targeted therapies have demonstrated to be highly effective in rescuing T cell anti-tumor effector functions. Amongst these the use of anti-PD1/PDL1 monoclonal antibodies are particularly efficacious in human therapies. Furthermore, clinical findings with PD1/PDL1 blockers over several cancer types demonstrate clinical benefit. Despite the successful results, the molecular mechanisms by which PD1-targeted therapies rescue T cell functions still remain elusive. Therefore, it is a key issue to uncover the molecular pathways by which these therapies exert its function in T cells. A profound knowledge of PDL1/PD1 mechanisms will surely uncover a new array of targets susceptible of therapeutic intervention. Here, we provide an overview of the molecular events underlying PD1-dependent T cell suppression in cancer.