Biology subjects

Minguet, S.

Publications and source records attributed to Minguet, S..

8 recordsLinked to original sources

bioRxiv2026

Postnatal Maturation of Dendritic Epidermal T Cells and Langerhans Cells Follows Distinct Differentiation Trajectories Independent of Microbiota

The mouse epidermis harbors two key resident immune populations--dendritic epidermal T cells (DETCs), a subset of invariant {gamma}{delta} T cells, and Langerhans cells (LCs), specialized tissue-resident macrophages--both of which play critical roles in immune surveillance, barrier integrity, and tissue homeostasis. While the fetal origin of both cell types has been defined, the cellular and molecular mechanisms that govern their postnatal fates following colonization of the epidermis around birth remain incompletely understood. Here, we present a combination of immunophenotyping- and transcriptome-resolved single-cell map of DETC and LC development in the mouse epidermis from late embryogenesis through adulthood. We delineate differentiation trajectories for both cell types, marked by distinct changes in morphology, proliferation, and transcriptional programming. Using mice deficient in {gamma}{delta} T cells, which lack canonical DETCs, we demonstrate that LCs develop independently of canonical DETCs likely due to the presence of {beta}DETCs. Moreover, analysis of germ-free mice and wildlings reveals that the postnatal development of both DETCs and LCs is independent of microbial colonization. Together, our findings define the core principles underlying the establishment of the mouse epidermal immune niche. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=168 SRC="FIGDIR/small/716534v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@18088a0org.highwire.dtl.DTLVardef@189e0f2org.highwire.dtl.DTLVardef@10f37d6org.highwire.dtl.DTLVardef@1ad59c_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2025

Controlling TCR and CAR activation by targeting LCK recruitment with a first-in-class small-molecule inhibitor

T-cell activation is driven by the recruitment of lymphocyte-specific protein tyrosine kinase (LCK) to the T-cell receptor (TCR), a critical step in initiating immune responses. Existing LCK inhibitors lack specificity because they target the conserved kinase domain shared by Src family kinases, resulting in off-target effects. Here, we introduce a novel strategy to selectively modulate T-cell activation by disrupting the interaction between the SH3 domain of LCK and the receptor kinase (RK) motif of CD3{varepsilon}. Using computational modeling and high-throughput virtual screening, we identified candidate compounds targeting the SH3(LCK) domain. Functional validation revealed that one compound, C10, selectively disrupted the SH3-RK interaction, leading to reduced TCR-driven activation and proliferation, while sparing activation via alternative receptors and B-cell responses. Moreover, C10 modulated the activity of CD3{varepsilon}-containing CAR and TRuC T cells, attenuating cytokine production and promoting a central-memory-like phenotype associated with enhanced persistence. These findings establish targeted disruption of LCK recruitment as a viable strategy for fine-tuning T-cell responses and propose SH3(LCK) as a druggable domain with therapeutic potential for autoimmune diseases, graft-versus-host disease, and optimizing CAR T-cell therapies.

immunology↗

bioRxiv2025

LCK deficiency in CD8 T cells leads to reduced proliferation and increased effector T-cell formation in mice

LCK is an SRC-family kinase that mediates the initial steps in T-cell antigen receptor signaling and governs positive and negative selection during thymocyte development. While its developmental role is well established, its functions in peripheral T-cell responses remain poorly defined. Here, we investigated the responses of wild-type and LCK-deficient TCR-transgenic OT-I T cells across two infection models and an autoimmune diabetes model. LCK-deficient T cells exhibited reduced antigen-induced proliferation but, paradoxically, displayed enhanced effector differentiation in vivo. This phenotype likely reflects dysregulation of specific TCR signaling pathways, as LCK was more critical for ERK and NFAT activation than for NF{kappa}B, AP-1, or AKT/mTOR signaling. T cells deficient in a related kinase FYN also showed a slight increase in effector cell formation, suggesting that effector differentiation is regulated by their combined activity rather than distinct non-redundant roles. Our results reveal that LCK has two intrinsic roles in T-cell responses - promoting proliferation while restraining effector differentiation. These findings provide new insight into the molecular mechanisms of T-cell activation in vivo with implications for understanding the pathophysiology of LCK deficiency in humans and optimizing adoptive T-cell therapies.

immunology↗

bioRxiv2025

Functional γδT-omics pipeline reveals compartmentalization of Vδ1⁺ T cell migration, tumor-reactivity, and clonality in human colorectal cancer

{gamma}{delta}T cells play a pivotal role in cancer immune surveillance, yet the current knowledge of their function across the compartments in solid tumors is meager. To address this gap, we developed a comprehensive {gamma}{delta}T-omics platform that integrates functional screening, biomimetic migration assays, {gamma}{delta}TCR repertoire analysis, and transcriptomic profiling. Using matched samples from 31 patients with microsatellite-stable colorectal cancer (CRC), we analyzed {gamma}{delta}T cells from peripheral blood (PBLs{gamma}{delta}), adjacent colon (LPLs{gamma}{delta}), primary tumors (pTILs{gamma}{delta}), and liver metastases (mTILs{gamma}{delta}). This approach uncovered striking compartmentalization of {gamma}{delta}T cell phenotypes, clonality, and function. Tumor-reactive, clonally expanded V{delta}1 {gamma}{delta}T cells were enriched in primary tumors and shared transcriptional and functional features with lamina propria lymphocytes (LPLs). In contrast, V{delta}1 {gamma}{delta}T cells from liver metastases lacked tumor reactivity, exhibited distinct {gamma}{delta}TCR repertoires, and expressed transcriptional signatures associated with TGF-{beta}-mediated suppression and cellular quiescence, suggesting they are shaped by tissue-specific environmental cues. CXCL16 secretion by tumor cells initiated V{delta}1 LPLs{gamma}{delta} migration, which was further amplified by {gamma}{delta}TCR-mediated CCL5 induction from pTILs{gamma}{delta}, leading to CCR5 downregulation and subsequent entrapment of pTILs{gamma}{delta} within the tumor microenvironment. Accordingly, our clinical data from an independent second cohort of 69 patients showed that infiltration by pTILs{gamma}{delta}, but not mTILs{gamma}{delta}, is associated with a protective effect against CRC progression. In summary, our study offers a compartment-resolved perspective on {gamma}{delta}T cell behavior in CRC, revealing key trafficking and functional mechanisms, and enabling the identification of novel tumor-reactive {gamma}{delta}TCRs and migratory cues to inform immunotherapeutic strategies for both primary and metastatic CRC. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=179 SRC="FIGDIR/small/671055v1_ufig1.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@ff3bborg.highwire.dtl.DTLVardef@14a7e1forg.highwire.dtl.DTLVardef@19e4de4org.highwire.dtl.DTLVardef@bc600_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2023

TCR/CD3-based synthetic antigen receptors (TCC) convey superior antigen sensitivity combined with high fidelity of activation

Low antigen sensitivity and a gradual loss of effector functions limit the clinical applicability of chimeric antigen receptor (CAR)-modified T-cells and call for alternative antigen receptor designs for effective T-cell-based cancer immunotherapy. Here we applied advanced microscopy to demonstrate that TCR/CD3-based synthetic constructs (TCC) outperform second-generation CAR formats with regard to conveyed antigen sensitivities by up to a thousand-fold. TCC-based antigen recognition occurred without adverse non-specific signaling, which is typically observed in CAR-T-cells, and did not depend - unlike sensitized peptide/MHC detection by conventional T-cells - on CD4- or CD8- coreceptor engagement. TCC-endowed signaling properties may prove critical when targeting antigens in low abundance and aiming for a durable anti-cancer response.

immunology↗

bioRxiv2022

Kidins220 promotes thymic iNKT cell development by reducing TCR signals, but enhances TCR signals in splenic iNKT cells

The stepwise development of thymic invariant natural killer T (iNKT) cells is controlled by the TCR signal strength. The scaffold protein Kinase D interacting substrate of 220 kDa (Kidins220) binds to the TCR regulating TCR signaling. T cell-specific Kidins220 knock-out (T-KO) mice contain severely decreased iNKT numbers. Very early in iNKT development TCR signals are reduced in the T-KO. In later steps, TCR signaling is increased in the T-KO leading to enhanced apoptosis of iNKT cells. Kidins220s absence affects the iNKT1 subset most as it requires the weakest TCR signals for development. We also show that in iNKT1 development, weak TCR signals promote the progressive loss of CD4. In the periphery, Kidins220 switches its role back to promoting TCR signaling as splenic T-KO iNKT cells produce less cytokines and show reduced TCR signaling after in vivo stimulation with -galactosylceramide. In conclusion, Kidins220 promotes or inhibits TCR signaling depending on the developmental context. summary statementWe demonstrate that the transmembrane scaffold protein Kidins220 switches its role twice in iNKT cell biology: from a positive to a negative regulator of TCR signal strength during thymic development and back to a positive regulator in the periphery.

immunology↗

bioRxiv2022

Breast cancer stem cell-derived tumors escape from γδ T cell immunosurveillance in vivo by modulating γδ T cell ligands

Triple negative breast cancer (TNBC) lacks targeted therapy options. TNBC is enriched in breast cancer stem cells (BCSCs), which play a key role in metastasis, chemoresistance, relapse and mortality. {gamma}{delta} T cells hold great potential in immunotherapy against cancer, and might be an alternative to target TNBC. {gamma}{delta} T cells are commonly observed to infiltrate solid tumors and have an extensive repertoire of tumor sensing, recognizing stress-induced molecules and phosphoantigens (pAgs) on transformed cells. We show that patient-derived triple negative BCSCs are efficiently recognized and killed by ex vivo expanded {gamma}{delta} T cells from healthy donors. Orthotopically xenografted BCSCs, however, were refractory to {gamma}{delta} T cell immunotherapy. Mechanistically, we unraveled concerted differentiation and immune escape: xenografted BCSCs lost stemness, expression of {gamma}{delta} T cell ligands, adhesion molecules and pAgs, thereby evading immune recognition by {gamma}{delta} T cells. Indeed, neither pro-migratory engineered {gamma}{delta} T cells, nor anti-PD-1 checkpoint blockade significantly prolonged overall survival of tumor-bearing mice. BCSC immune escape was independent of the immune pressure exerted by the {gamma}{delta} T cells, and could be pharmacologically reverted by Zoledronate or IFN- treatment. These results pave the way for novel combinatorial immunotherapies for TNBC.

immunology↗

bioRxiv2022

Kidins220 regulates the development of B cells bearing the {lambda} light chain

The ratio between Ig{kappa} and Ig{lambda} light chain (LC)-expressing B cells varies considerably between species. We recently identified Kinase D-interacting substrate of 220 kDa (Kidins220) as an interaction partner of the BCR. In vivo ablation of Kidins220 in B cells resulted in a marked reduction of {lambda}LC-expressing B cells. Kidins220 knockout B cells fail to open and recombine the genes of the{lambda} LC locus, even in genetic scenarios where the{kappa} LC genes cannot be rearranged or where the {kappa}LC confers autoreactivity.{kappa} LC gene recombination and expression in Kidins220-deficient B cells is normal. Kidins220 regulates the development of {lambda}LC B cells by enhancing the survival of developing B cells and thereby extending the time-window in which the{lambda} LC locus opens and the genes are rearranged and transcribed. Further, our data suggest that Kidins220 guarantees optimal pre-BCR and BCR signaling to induce{lambda} LC locus opening and gene recombination during B cell development and receptor editing. One Sentence SummaryWe demonstrate that the scaffold protein Kidins220 regulates the development of {lambda}LC B cells by supporting B cell precursor survival and optimizing pre-BCR and BCR signaling to open, recombine, and transcribe the genes of the{lambda} LC locus.

immunology↗