Reprogramming dendritic cells through the immunological synapse: A two-way street.

Dendritic cells (DCs) bridge innate and adaptive immunity. Their main function is to present antigens to prime T cells and initiate and shape adaptive responses. Antigen presentation takes place through intimate contacts between the two cells, termed immune synapses (IS). During the formation of IS, information travels towards the T-cell side to induce and tune its activation; but it also travels in reverse via engagement of membrane receptors and within extracellular vesicles transferred to the DC. Such reverse information transfer and its consequences on DC fate have been largely neglected. Here, we review the events and effects of IS-mediated antigen presentation on DCs. In addition, we discuss novel technological advancements that enable monitoring DCs interactions with T lymphocytes, the main effects of DCs undergoing productive IS (postsynaptic DCs, or psDCs), and how reverse information transfer could be harnessed to modulate immune responses for therapeutic intervention.S

Immune Regulation by Dendritic Cell Extracellular Vesicles in Cancer Immunotherapy and Vaccines.

Extracellular vesicles (EVs) play a crucial role in intercellular communication as vehicles for the transport of membrane and cytosolic proteins, lipids, and nucleic acids including different RNAs. Dendritic cells (DCs)-derived EVs (DEVs), albeit variably, express major histocompatibility complex (MHC)-peptide complexes and co-stimulatory molecules on their surface that enable the interaction with other immune cells such as CD8+ T cells, and other ligands that stimulate natural killer (NK) cells, thereby instructing tumor rejection, and counteracting immune-suppressive tumor microenvironment. Malignant cells oppose this effect by secreting EVs bearing a variety of molecules that block DCs function. For instance, tumor-derived EVs (TDEVs) can impair myeloid cell differentiation resulting in myeloid-derived suppressor cells (MDSCs) generation. Hence, the unique composition of EVs makes them suitable candidates for the development of new cancer treatment approaches including prophylactic vaccine targeting oncogenic pathogens, cancer vaccines, and cancer immunotherapeutics. We offer a perspective from both cell sides, DCs, and tumor cells, on how EVs regulate the antitumor immune response, and how this translates into promising therapeutic options by reviewing the latest advancement in DEV-based cancer therapeutics.This work was supported by grant SAF2017-82886-R from the Spanish Ministry of Economy and Competitiveness (MINECO), grant S2017/BMD-3671-INFLAMUNE-CM from the Comunidad de Madrid, a grant from the Ramón Areces Foundation “Ciencias de la Vida y la Salud” (XIX Concurso-2018) and a grant from Ayudas Fundación BBVA a Equipos de Investigación Científica (BIOMEDICINA-2018), the Fundació Marató TV3 (grant 122/C/2015) and “La Caixa” Banking Foundation (HR17-00016). BIOIMID (PIE13/041) from Instituto de Salud Carlos III, CIBER Cardiovascular (CB16/11/00272, Fondo de Investigación Sanitaria del Instituto de Salud Carlos III and co-funding by Fondo Europeo de Desarrollo Regional FEDER). D.C.-F. is supported by a Fellowship from “la Caixa” Foundation (LCF/BQ/DR19/11740010). I.F.-D. is supported by a Fellowship from Spanish Ministry of Science, Innovation and Universities (FPU15/02539). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación (MCIN) and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505).N

G protein-coupled receptor kinase 2 (GRK2) as a multifunctional signaling hub

Accumulating evidence indicates that G protein-coupled receptor kinase 2 (GRK2) is a versatile protein that acts as a signaling hub by modulating G protein-coupled receptor (GPCR) signaling and also via phosphorylation or scaffolding interactions with an extensive number of non-GPCR cellular partners. GRK2 multifunctionality arises from its multidomain structure and from complex mechanisms of regulation of its expression levels, activity, and localization within the cell, what allows the precise spatio-temporal shaping of GRK2 targets. A better understanding of the GRK2 interactome and its modulation mechanisms is helping to identify the GRK2-interacting proteins and its substrates involved in the participation of this kinase in different cellular processes and pathophysiological contexts.Our laboratories are supported by Ministerio de Ciencia, Innovación y Universidades (Grant SAF2017-84125-R to FM and SAF2017-82886-R to FSM), CIBERCV-Instituto de Salud Carlos III, Spain (Grant B16/11/00278 to F.M, co-funded with European FEDER contribution), Instituto de Salud Carlos III, Spain (Grant PI17-00576 to PP and grant PI18/01662 to CR), Fundacion Ramón Areces (to FM) and Programa de Actividades en Biomedicina de la Comunidad de Madrid-B2017/BMD-3671-INFLAMUNE to FM and FSM. We also acknowledge institutional support to the CBMSO from Fundación Ramón ArecesS

Control of Immunoregulatory Molecules by miRNAs in T Cell Activation

MiRNA targeting of key immunoregulatory molecules fine-tunes the immune response. This mechanism boosts or dampens immune functions to preserve homeostasis while supporting the full development of effector functions. MiRNA expression changes during T cell activation, highlighting that their function is constrained by a specific spatiotemporal frame related to the signals that induce T cell-based effector functions. Here, we update the state of the art regarding the miRNAs that are differentially expressed during T cell stimulation. We also revisit the existing data on miRNA function in T cell activation, with a special focus on the modulation of the most relevant immunoregulatory molecules.We thank Dr M. Vicente-Manzanares for critical reading of the manuscript and for assistance with English editing. This study was supported by the following grants from the Spanish Ministry of Economy and Competitiveness, (grant SAF2017-82886-R to FSM), CIBER CARDIOVASCULAR and PIE 13.0004-BIOIMID from the Instituto de Salud Carlos III (Fondo de Investigacion Sanitaria del Instituto de Salud Carlos III with co-funding from the Fondo Europeo de Desarrollo Regional; FEDER), Programa de Actividades en Biomedicina de la Comunidad de Madrid-B2017/BMD-3671-INFLAMUNE to FS-M, and ERC-2011-AdG294340-GENTRIS to FS-M. The Centro Nacional de Investigaciones Cardiovasculares (CNIC) is supported by the Spanish Ministry of Economy and Competitiveness (MINECO) and the Pro-CNIC Foundation and is a Severo Ochoa Center of Excellence (MINECOaward SEV-2015-0505). AR-G is supported by the FPU program (Spanish Ministry of Education). LF-M is funded by the CIBER CARDIOVASCULAR.S

Function of CD44(Pgp-1) homing receptor in human T cell precursors

T cell precursors migrate from extrathymic hematopoietic tissues and dlfferentlate after encountering the thymic microenvironment. We asked whether human T cell precursors express the CD44(Pgp-l/gp90HR) class of homing receptors that have been implicated in the traffic of hematopoietic cells, such as lymphocyte entry to peripheral lymphold organs. Flow cytometry and immunoprecipitation studies demonstrate that CD7+34+, CD1-2-3-4-8- 14-16-20- cells in bone marrow and thymus, which have been shown to exhibit features of T cell precursors, bear CD44. Immunohlstologoical studies show that clusters of thymocytes in the subcapsular and the inner cortex and most medullary thymocytes are clearly CD44+, whereas the expression of CD44 is selectively downregulated in CD3- and CD3low functionally incompetent cortical thymocytes. The expression of CD44 is not restricted to T cell precursors but also occurs in thymic stroma, which bear a different molecular species of CD44. CD44-specific antibodies exert stimulatory effects on T cell precursors, a process that is dependent on stromal cells. We postulate that CD44 might be an adhesion molecule for precursor homing to thymus and that it participates in cell-to-cell interactions within the thymic environmen

Extracellular Vesicle-Mediated Immune Regulation of Tissue Remodeling and Angiogenesis After Myocardial Infarction

Myocardial ischemia-related disorders constitute a major health problem, being a leading cause of death in the world. Upon ischemia, tissue remodeling processes come into play, comprising a series of inter-dependent stages, including inflammation, cell proliferation and repair. Neovessel formation during late phases of remodeling provides oxygen supply, together with cellular and soluble components necessary for an efficient myocardial reconstruction. Immune system plays a central role in processes aimed at repairing ischemic myocardium, mainly in inflammatory and angiogenesis phases. In addition to cellular components and soluble mediators as chemokines and cytokines, the immune system acts in a paracrine fashion through small extracellular vesicles (EVs) release. These vesicular structures participate in multiple biological processes, and transmit information through bioactive cargoes from one cell to another. Cell therapy has been employed in an attempt to improve the outcome of these patients, through the promotion of tissue regeneration and angiogenesis. However, clinical trials have shown variable results, which put into question the actual applicability of cell-based therapies. Paracrine factors secreted by engrafted cells partially mediate tissue repair, and this knowledge has led to the hypothesis that small EVs may become a useful tool for cell-free myocardial infarction therapy. Current small EVs engineering strategies allow delivery of specific content to selected cell types, thus revealing the singular properties of these vesicles for myocardial ischemia treatment.This work was supported by grants to AA-S (FIS PI15/01491) and to FS-M (grants SAF2014-55579-R and SAF2017-82886-R to FS-M), BIOIMID PIE13/041 and CIBER CARDIOVASCULAR from the Instituto de Salud Carlos III (Fondo de Investigación Sanitaria del Instituto de Salud Carlos III with co-funding from the Fondo Europeo de Desarrollo Regional; FEDER), Programa de Actividades en Biomedicina de la Comunidad de Madrid-B2017/BMD-3671-INFLAMUNE to FS-M, and ERC2011-AdG294340-GENTRIS to FS-M, and Fundació La Marató TV3 (20152330 31). The Centro Nacional de Investigaciones Cardiovasculares (CNIC) is supported by the Spanish Ministry of Economy and Competitiveness (MINECO) and the ProCNIC Foundation and is a Severo Ochoa Center of Excellence (MINECO award SEV-2015-0505).S

When should we order a next generation sequencing test in a patient with cancer?

Technical advances in genome sequencing and the implementation of next-generation sequencing (NGS) in clinical oncology have paved the way for individualizing cancer patient therapy based on molecular profiles. When and how to use NGS testing in the clinic is at present an unsolved issue, although new research results provide evidence favoring this approach in some types of advanced cancer. Clinical research is evolving rapidly, from basket and umbrella trials to adaptative design precision oncology clinical studies, and genomic and molecular data often displace the classical clinical validation procedures of biomarkers. In this context, physicians must be aware of the clinical evidence behind these new biomarkers and NGS tests available, in order to use them in the right moment, and with a critical point of view. This review will present the status of currently available targeted drugs that can be effective based on actionable molecular alterations, and the NGS tests that are currently available, offering a practical guide for the application of Clinical Precision Oncology in the real world routine practice.probability of identifying a targetable mutation is low[62], the canceris in early stages with recognized and effective forms of standardtreatment, or the patient has an irreversible disease with very shortlife-expectancy. As with any other laboratory test, doctors andpatients must be sure before ordering an NGS test that its result willhave an impact of the therapeutic plan. In any case, standard single-gene molecular testing must always be performed when indicated,since important therapeutic targets might be potentially missed if nomolecular analyses were performed.Clinical trials are showing that NGS testing can have an impact inthe response rate and progression-free survival of patients, and cantherefore be a very useful strategy leading to new molecularly-tar-geted treatment indications. Key factors responsible for improvedresults in precision-oriented clinical research, include refining themolecular pathways studied, developing molecular testing that inte-grates standarised genomic tests with transcriptomic analysis andimmunohistochemistry, selecting more active targeted agents,designing combinations of targeted agents -also with other forms oftherapy, and providing early treatment recommendations with avail-able Molecular Multidisciplinary Boards. Interdisciplinary discussionare very important to help with the interpretation of unclear molecu-lar results that are oftentimes seen with NGS testing.Important unsolved issues that will need to be addressed in thefuture include deciding which is the best tissue to perform NGS (pri-mary tumor vs metastasis, tumor DNA vs circulating tumor DNA),when is the right moment to test (atfirst diagnosis of advanced dis-ease or when the disease is refractory), and whether there are NGSclinical trial designs that allow for the use of control groups. Finally,using a complete informed consent before NGS testing and communi-cating NGS reports to patients are two very important aspects of theprocedure that have raised ethical concerns, and that must be alwaysaddressed by the practicing oncologists when ordering a NGS test.Search strategy and selection criteriaWe identified references through PubMed with the search terms“cancer AND NGS,”“cancer AND next generation sequencing,”“can-cer AND genomics,”for articles published to March 30, 2020. Thefinalreference list was generated on the basis of originality and relevanceto the broad scope of this Review.FundingThis Review was funded in part by research funds from projectsPIE15/00068andPI17/01865(Instituto de Salud Carlos III) awardedto RC, projectsJR17/00007andPI17/008(Instituto de Salud CarlosIII), awarded to NR-L,PI15/01491andPI19/00549(Instituto de SaludCarlos III) awarded to AA, projectsSAF2017 82886-R(Ministerio deEconomía y Competitividad), INDISNET-S2011/BMD-2332(Fundaci on Ram on Areces), andHR17-00016("La Caixa" Foundation)awarded to FS-M, and projectsPI16/00354(Instituto de Salud CarlosIII) andB2017/BMD-3733from the Consejería de Educaci on, Juventudy Deporte, Comunidad de Madrid, awarded to MQ-F. The manuscriptis part of the activities of the endowed Chair of Personalised PrecisionOncology, Universidad Aut onoma de Madrid (UAM-Fundaci on Insti-tuto Roche)S

miRNA profiling during antigen-dependent T cell activation: A role for miR-132-3p

microRNAs (miRNAs) are tightly regulated during T lymphocyte activation to enable the establishment of precise immune responses. Here, we analyzed the changes of the miRNA profiles of T cells in response to activation by cognate interaction with dendritic cells. We also studied mRNA targets common to miRNAs regulated in T cell activation. pik3r1 gene, which encodes the regulatory subunits of PI3K p50, p55 and p85, was identified as target of miRNAs upregulated after T cell activation. Using 3'UTR luciferase reporter-based and biochemical assays, we showed the inhibitory relationship between miR-132-3p upregulation and expression of the pik3r1 gene. Our results indicate that specific miRNAs whose expression is modulated during T cell activation might regulate PI3K signaling in T cells.We thank Miguel Vicente-Manzanares for help with English editing and Almudena R. Ramiro for helpful discussions. We appreciate help from Gloria Martinez del Hoyo on DCs experiments set up. We also thank the CNIC Genomics, Bioinformatics and Cellomics Units for technical support. This work was supported by grants SAF2014-55579R from Ministerio de Economia y Competitividad-Spain, ERC-2011-AdG 294340-GENTRIS, CIBER CARDIOVASCULAR (FEDER and Instituto de Salud Carlos III), PIE-13-00041 and INDISNET S2011-BMD-2332 (F.S.M.). The Centro Nacional de Investigaciones Cardiovasculares (CNIC, Spain) is supported by the Ministerio de Economia y Competitividad-Spain and the Pro-CNIC Foundation.S

Identification of Genes Responsive to Solar Simulated UV Radiation in Human Monocyte-Derived Dendritic Cells

Ultraviolet (UV) irradiation has profound effects on the skin and the systemic immune system. Several effects of UV radiation on Dendritic cells (DCs) functions have been described. However, gene expression changes induced by UV radiation in DCs have not been addressed before. In this report, we irradiated human monocyte-derived DCs with solar-simulated UVA/UVB and analyzed regulated genes on human whole genome arrays. Results were validated by RT-PCR and further analyzed by Gene Set Enrichment Analysis (GSEA). Solar-simulated UV radiation up-regulated expression of genes involved in cellular stress and inflammation, and down-regulated genes involved in chemotaxis, vesicular transport and RNA processing. Twenty four genes were selected for comparison by RT-PCR with similarly treated human primary keratinocytes and human melanocytes. Several genes involved in the regulation of the immune response were differentially regulated in UVA/UVB irradiated human monocyte-derived DCs, such as protein tyrosine phosphatase, receptor type E (PTPRE), thrombospondin-1 (THBS1), inducible costimulator ligand (ICOSL), galectins, Src-like adapter protein (SLA), IL-10 and CCR7. These results indicate that UV-exposure triggers the regulation of a complex gene repertoire involved in human-DC–mediated immune responses

Transfer of extracellular vesicle-microRNA controls germinal center reaction and antibody production

Intercellular communication orchestrates effective immune responses against disease-causing agents. Extracellular vesicles (EVs) are potent mediators of cell-cell communication. EVs carry bioactive molecules, including microRNAs, which modulate gene expression and function in the recipient cell. Here, we show that formation of cognate primary T-B lymphocyte immune contacts promotes transfer of a very restricted set of T-cell EV-microRNAs (mmu-miR20-a-5p, mmu-miR-25-3p, and mmu-miR-155-3p) to the B cell. Transferred EV-microRNAs target key genes that control B-cell function, including pro-apoptotic BIM and the cell cycle regulator PTEN. EV-microRNAs transferred during T-B cognate interactions also promote survival, proliferation, and antibody class switching. Using mouse chimeras with Rab27KO EV-deficient T cells, we demonstrate that the transfer of small EVs is required for germinal center reaction and antibody production in vivo, revealing a mechanism that controls B-cell responses via the transfer of EV-microRNAs of T-cell origin. These findings also provide mechanistic insight into the Griscelli syndrome, associated with a mutation in the Rab27a gene, and might explain antibody defects observed in this pathogenesis and other immune-related and inflammatory disorders.This manuscript was funded by grants SAF2017-82886-R (FS-M) from the Spanish Ministry of Economy and Competitiveness; CAM (S2017/BMD-3671-INFLAMUNE-CM) from the Comunidad de Madrid (FS-M); CIBERCV (CB16/11/00272), BIOIMID PIE13/041 from the Instituto de Salud Carlos III and from the Fundación La MaratóTV3(grant122/C/2015). The current research has received funding from “la Caixa” Foundation under the project code HR17-00016. VGY is supported by the AECC foundation. A.R.R. is supported by CNIC funding. This project was funded by the Spanish Ministerio de Ciencia, Innovacion y Universidades SAF2016-75511-R, and La Caixa Health Research Program HR17-00247 grant to A.R.R. Grants from Ramón Areces Foundation “Ciencias de la Vida y de la Salud” (XIX Concurso-2018) and from Ayuda Fundación BBVA y Equipo de Investigación Científica (BIOMEDICINA-2018) (to FSM). The CNIC is supported by the Ministerio de Ciencia, Innovacion y Universidades and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S