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

The leukocyte activation receptor CD69 controls T cell differentiation through its interaction with galectin-1

CD69 is involved in immune cell homeostasis, regulating the T cell-mediated immune response through the control of Th17 cell differentiation. However, natural ligands for CD69 have not yet been described. Using recombinant fusion proteins containing the extracellular domain of CD69, we have detected the presence of a ligand(s) for CD69 on human dendritic cells (DCs). Pulldown followed by mass spectrometry analyses of CD69-binding moieties on DCs identified galectin-1 as a CD69 counterreceptor. Surface plasmon resonance and anti-CD69 blocking analyses demonstrated a direct and specific interaction between CD69 and galectin-1 that was carbohydrate dependent. Functional assays with both human and mouse T cells demonstrated the role of CD69 in the negative effect of galectin-1 on Th17 differentiation. Our findings identify CD69 and galectin-1 to be a novel regulatory receptor-ligand pair that modulates Th17 effector cell differentiation and functionThis work was funded by grants SAF2011-25834 and ERC-2011AdG 294340-GENTRIS to F.S.-M., RECAVA RD06/0014 from the Fondo de Investigaciones Sanitarias to J.V. and F.S.-M., and INDISNET 01592006 from the Comunidad de Madrid to F.S.-M. and P.M. and by grants from the Ministerio de Economia y Competitividad (PI11/01562 to P.N.) and the Generalitat de Catalunya-AGAUR (2009SGR1409 to P.N.). The Ministry of Science and Innovation and the Pro-CNIC Foundation support CNI

Natural killer (NK) cell-derived extracellular-vesicle shuttled microRNAs control T cell responses.

Natural killer (NK) cells recognize and kill target cells undergoing different types of stress. NK cells are also capable of modulating immune responses. In particular, they regulate T cell functions. Small RNA next-generation sequencing of resting and activated human NK cells and their secreted extracellular vesicles (EVs) led to the identification of a specific repertoire of NK-EV-associated microRNAs and their post-transcriptional modifications signature. Several microRNAs of NK-EVs, namely miR-10b-5p, miR-92a-3p, and miR-155-5p, specifically target molecules involved in Th1 responses. NK-EVs promote the downregulation of GATA3 mRNA in CD4+ T cells and subsequent TBX21 de-repression that leads to Th1 polarization and IFN-γ and IL-2 production. NK-EVs also have an effect on monocyte and moDCs (monocyte-derived dendritic cells) function, driving their activation and increased presentation and costimulatory functions. Nanoparticle-delivered NK-EV microRNAs partially recapitulate NK-EV effects in mice. Our results provide new insights on the immunomodulatory roles of NK-EVs that may help to improve their use as immunotherapeutic tools.This manuscript was funded by grants PDI-2020-120412RB-I00 and PDC2021- 121719-I00 (FS-M) and PID2020- 119352RB-I00 (AS) from the Spanish Ministry of Economy and Competitiveness; CAM (S2017/BMD3671-INFLAMUNE-CM) from the Comunidad de Madrid (FS-M). CIBERCV (CB16/11/00272) and BIOIMID PIE13/041 from the Instituto de Salud Carlos. The current research has received funding from 'la Caixa' Foundation under the project code HR17-00016. 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). IMDEA Nanociencia acknowledges support from the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (MINECO, CEX2020-001039-S). SGD is supported by a grant from the Spanish Ministry of Universities. Authors thank Dr Miguel Vicente-Manzanares for critical review and editing. We also thank Dr Francisco Urbano and Dr Covadonga Aguado for their support with EM (TEM facilities, Universidad Autónoma de Madrid).S

Targeting L-type amino acid transporter 1 in innate and adaptive T cells efficiently controls skin inflammation

BACKGROUND: Psoriasis is a frequent inflammatory skin disease that is mainly mediated by IL-23, IL-1β, and IL-17 cytokines. Although psoriasis is a hyperproliferative skin disorder, the possible role of amino acid transporters has remained unexplored. OBJECTIVE: We sought to investigate the role of the essential amino acid transporter L-type amino acid transporter (LAT) 1 (SLC7A5) in psoriasis. METHODS: LAT1 floxed mice were crossed to Cre-expressing mouse strains under the control of keratin 5, CD4, and retinoic acid receptor-related orphan receptor γ. We produced models of skin inflammation induced by imiquimod (IMQ) and IL-23 and tested the effect of inhibiting LAT1 (JPH203) and mammalian target of rapamycin (mTOR [rapamycin]). RESULTS: LAT1 expression is increased in keratinocytes and skin-infiltrating lymphocytes of psoriatic lesions in human subjects and mice. LAT1 deletion in keratinocytes does not dampen the inflammatory response or their proliferation, which could be maintained by increased expression of the alternative amino acid transporters LAT2 and LAT3. Specific deletion of LAT1 in γδ and CD4 T cells controls the inflammatory response induced by IMQ. LAT1 deletion or inhibition blocks expansion of IL-17-secreting γ4+δ4+ and CD4 T cells and dampens the release of IL-1β, IL-17, and IL-22 in the IMQ-induced model. Moreover, inhibition of LAT1 blocks expansion of human γδ T cells and IL-17 secretion by human CD4 T cells. IL-23 and IL-1β stimulation upregulates LAT1 expression and induces mTOR activation in IL-17+ γδ and TH17 cells. Deletion or inhibition of LAT1 efficiently controls IL-23- and IL-1β-induced phosphatidylinositol 3-kinase/AKT/mTOR activation independent of T-cell receptor signaling. CONCLUSION: Targeting LAT1-mediated amino acid uptake is a potentially useful immunosuppressive strategy to control skin inflammation mediated by the IL-23/IL-1β/IL-17 axis.Funding This manuscript has been funded by grants SAF 2017-82886-R (FS-M) and SAF 2013-42850-R (MF) from the Spanish Ministry of Economy and Competitiveness; CAM (S2017/BMD-3671-INFLAMUNE-CM) from the Comunidad de Madrid (FS-M); CIBERCV, BIOIMID PIE13/041 from Instituto de Salud Carlos III and Fundación La Marató TV3 (20152330 31). The project leading to these results has also received funding from FUNDACIÓN BBVA A EQUIPOS DE INVESTIGACIÓN CIENTÍFICA 2018 and from “la Caixa” Banking Foundation under the project code HR17-00016 (FS-M), and from Agencia Estatal de Investigación, Fondo Europeo de Desarrollo Regional PI17/01972 (E.D).S

CD69 modulates sphingosine-1-phosphate-induced migration of skin dendritic cells

In this study, we have investigated the role of CD69, an early inducible leukocyte activation receptor, in murine dendritic cell (DC) differentiation, maturation, and migration. Skin DCs and DC subsets present in mouse lymphoid organs express CD69 in response to maturation stimuli. Using a contact sensitization model, we show that skin DCs migrated more efficiently to draining lymph nodes (LNs) in the absence of CD69. This was confirmed by subcutaneous transfer of CD69-/- DCs, which presented an increased migration to peripheral LNs. Two-photon microscopy analysis showed that once DCs reached the LNs, CD69 deficiency did not alter DC interstitial motility in the LNs. Chemotaxis to sphingosine-1-phosphate (S1P) was enhanced in CD69-/- DCs compared with wild-type DCs. Accordingly, we detected a higher expression of S1P receptor type-1 (S1P(1)) by CD69-/- DCs, whereas S1P(3) expression levels were similar in wild-type and CD69-/- DCs. Moreover, in vivo treatment with S1P analogs SEW2871 and FTY720 during skin sensitization reduced skin DC migration to peripheral LNs. These results suggest that CD69 regulates S1P-induced skin DC migration by modulating S1P(1) function. Together, our findings increase our knowledge on DC trafficking patterns in the skin, enabling the development of new directed therapies using DCs for antigen (Ag) delivery