Biology subjects

Luche, H.

Publications and source records attributed to Luche, H..

6 recordsLinked to original sources

bioRxiv2026

CD44-CD206 axis drives dendritic cell loss and immunosuppression in immaturely glycosylated bladder tumours

Antigen-presenting-cell dysfunction drives immune exclusion, but how tumour glycans disable these cells remains incompletely defined. Immature O-glycosylation, marked by Tn and sialyl-Tn antigens, drives myeloid dysfunction in bladder cancer. Transcriptomics and human tumour profiling linked this state to reduced representation of antigen-presenting myeloid cells and attenuated lymphoid-effector programmes. In glycoengineered models, immature O-glycans promoted immunoregulatory macrophage phenotypes and contact-dependent death of monocyte-derived dendritic cells (moDCs), while surviving cells showed impaired maturation and T-cell activation. Tumour-cell CD44 standard isoform was required for DC death, which was accompanied by inflammasome-associated proteins and gasdermin D cleavage, consistent with pyroptosis. Receptor-discovery approaches converged on CD206, which bound immaturely glycosylated CD44. CD206 blockade restored DC viability. In immunocompetent mice, immature glycosylation accelerated tumour growth and depleted conventional DCs, whereas CD206 blockade restrained tumour progression and restored local and nodal myeloid and lymphoid immunity. These findings identify CD44-CD206 as a targetable glycoimmune checkpoint that promotes immune exclusion.

immunology↗

bioRxiv2025

Virus-against-virus dominant-negative interference strategy targeting a viral CC chemokine prevents cytomegalovirus-related neurodevelopmental pathogenesis

BackgroundCongenital cytomegalovirus (CMV) infections are one leading cause of human neurodevelopmental disorders. Increasing evidence for the pathogenic involvement of brain immune alterations was obtained in the recent years. Host and virus-encoded chemokines might play important roles in CMV-related neuropathogenesis by regulating leukocyte trafficking and microglia recruitment in the CMV-infected brains, and by interfering with key neurodevelopmental steps. In a rat model of CMV infection of the fetal brain in utero that leads to detrimental neurologic and other severe phenotypes postnatally, we reported on the early alteration of microglia and on the infiltration of the infected brains by lymphoid and myeloid cells. Particularly, expression of the r129 gene encoding the viral chemokine RCK3 was detected as early as 24h post-infection; together with the previously reported chemotaxis properties exerted by RCK3 on lymphocytes and on macrophages in vitro, this suggested that RCK3 might be involved in the brain immune cell alterations seen in the CMV-infected developing brains, and in the related neuropathogenesis. MethodsInfection of the rat fetal brain was done by intracerebroventricular injections in utero of either rat CMV encoding wild-type (wt) RCK3 (RCMV-wt), or a mutant CMV counterpart encoding RCK3 with a deletion in its chemokine domain (RCMV-r129{Delta}NT). As RCMV-r129{Delta}NT had shown dominant-negative effects on the chemotaxis properties of RCK3 in vitro, simultaneous and successive co-infection rescue assays were also performed. The detrimental postnatal phenotypes in vivo and the epileptiform activity ex vivo usually detected after infection of the rat developing brain with RCMV-wt were monitored in the RCMV-r129{Delta}NT condition and in co-infection assays. ResultsIn sharp contrast with RCMV-wt whose infection of the fetal brain led to decreased postnatal survival, impaired sensorimotor development, hindlimb hyperextension and epileptic seizures in neonatal pups, RCMV-r129{Delta}NT infection was not associated with any severe postnatal phenotype in vivo. Consistently, the epileptiform activity recorded in most neocortical slices from RCMV-wt-infected pups was not detected in any slice from RCMV-r129{Delta}NT-infected pups. Simultaneous co-infection assays led to dramatic prevention against the postnatal phenotypes in vivo and the altered network activity ex vivo, revealing a dose-dependent rescuing effect exerted by RCMV-r129{Delta}NT on RCMV-wt. Importantly, successful rescue was also obtained when the mutant RCMV-r129{Delta}NT was inoculated in the fetal brains either before or after infection with RCMV-wt. SignificanceOur data demonstrate the crucial neuropathogenic role of RCK3 CMV chemokine in vivo. The dramatic success and apparent safety of the dominant-negative RCK3 rescue assays in vivo provide a proof-of-principle for the beneficial use of a virus-against-virus approach against CMV-related pathogenesis.

neuroscience↗

bioRxiv2023

Deconstructing Complexity: A Computational Topology Approach to Trajectory Inference in the Human Thymus with tviblindi

Understanding complex, organ-level single-cell datasets represents a formidable interdisciplinary challenge. This study aims to describe developmental trajectories of thymocytes and mature T cells. We developed tviblindi, a trajectory inference algorithm that integrates several autonomous modules - pseudotime inference, random walk simulations, real-time topological classification using persistent homology, and autoencoder-based 2D visualization using the vaevictis algorithm. This integration facilitates interactive exploration of developmental trajectories, revealing not only the canonical CD4 and CD8 development but also offering insights into checkpoints such as TCR{beta} selection and positive/negative selection. Furthermore, tviblindi allowed us to thoroughly characterize thymic regulatory T cells, tracing their development passed the negative selection stage to mature thymic regulatory T cells. At the very end of the developmental trajectory we discovered a previously undescribed subpopulation of thymic regulatory T cells. Experimentally, we confirmed its extensive proliferation history and an immunophenotype characteristic of activated and recirculating cells. tviblindi represents a new class of methods that is complementary to fully automated trajectory inference tools. It offers a semi-automated tool that leverages features derived from data in an unbiased and mathematically rigorous manner. These features include pseudotime, homology classes, and appropriate low-dimensional representations. These features can be integrated with expert knowledge to formulate hypotheses regarding the underlying dynamics, tailored to the specific trajectory or biological process under investigation.

immunology↗

bioRxiv2022

Anti-HVEM mAb therapy improves antitumoral immunity both in vitro and in vivo, in a novel transgenic mouse model expressing human HVEM and BTLA molecules challenged with HVEM expressing tumors

BackgroundTNFRF-14/HVEM is the ligand for BTLA and CD160 negative immune co-signaling molecules as well as viral proteins. Its expression is dysregulated with an overexpression in tumors and a connection with tumors of adverse prognosis. MethodsWe developed C57BL/6 mouse models co-expressing human huBTLA and huHVEM as well as antagonistic monoclonal antibodies (mAbs) that completely prevent the interactions of HVEM with its ligands. ResultsHere, we show that the anti-HVEM18-10 mAb increases primary human {beta}-T cells activity alone (CIS-activity) or in the presence of HVEM-expressing lung or colorectal cancer cells in vitro (TRANS-activity). Anti-HVEM18-10 synergizes with anti-PD-L1 mAb to activate T cells in the presence of PDL-1 positive tumors, but is sufficient to trigger T cell activation in the presence of PD-L1 negative cells. In order to better understand HVEM18-10 effect in vivo and especially disentangle its CIS and TRANS effects, we developed a knock-in (KI) mouse model expressing human BTLA (huBTLA+/+) and a KI mouse model expressing both human BTLA and human HVEM (huBTLA+/+ /huHVEM+/+ (DKI)). In vivo pre-clinical experiments performed in both mouse models showed that HVEM18-10 treatment was efficient to decrease human HVEM+ tumor growth. In the DKI model, anti-HVEM 18-10 treatment induces a decrease of exhausted CD8+ T cells and regulatory T cells and an increase of Effector memory CD4+ T cells within the tumor. Interestingly, mice which completely rejected tumors ({+/-} 20%) did not develop tumors upon re-challenge in both settings, therefore showing a marked T cell-memory phenotype effect. ConclusionsAltogether, our preclinical models validate anti-HVEM18-10 as a promising therapeutic antibody to use in clinics as a monotherapy or in combination with existing immunotherapies (anti-PD1/anti-PDL-1/anti-CTLA-4).

immunology↗

bioRxiv2022

The dual character of the inhibitory functions of CD6

T-cell membrane scaffold proteins play important roles in T cell biology, functioning as multi-functional signaling hubs. CD6 assembles a large intracellular signalosome but, unlike typical membrane-attached scaffolds like LAT or PAG, it has a sizeable ectodomain that binds a well-characterized ligand, CD166. It is unclear whether CD6 has net inhibitory or costimulatory functions or how its ectodomain influences these activities. To explore these questions, we dissected the signaling functions of the extracellular and cytoplasmic regions of CD6. We found that CD6 was delivered to the immunological synapse and suppressed T cell responsiveness in vitro wholly dependently of its cytoplasmic domain, indicating that CD6 very potently imposes tonic inhibition, acting as a structural and signaling inhibitory hub. However, the cell-intrinsic suppression of autoimmunity by CD6 in vivo was also impacted by extracellular interactions, demonstrated by the increased susceptibility of mice to experimental autoimmune encephalomyelitis after removal of the ligand binding region of the ectodomain of CD6. Our work identifies CD6 as a new class of on/off switching scaffold-receptor that constrains immune responsiveness at two speeds. First, it sets signaling thresholds via tonic inhibition, functioning as a cytoplasmic membrane-bound scaffold and, second, by cycling between signaling-enabling and signalinginhibiting ectodomain isoforms it functions as an immune checkpoint.

immunology↗

bioRxiv2022

CD5L constraints acute and systemic inflammation and can be a novel potent therapeutic agent against sepsis

The global burden of sepsis, with an estimated 49 million cases and 11 million deaths in 2017, often passes unnoticed to the general public even though it is the direct cause of nearly 20% of all deaths worldwide. This unawareness is perhaps due to misconceptions, or miscoding in the reporting of the ultimate causes of death, as in many diseases it is not the actual infectious agent that causes the biggest harm. Rather, it is the uncontrolled inflammation leading to septic shock that is the most menacing manifestation associated with many infections, and becomes deadly serious once it has passed the stage where anti-microbial drugs no longer have any effect to inactivate or destroy the pathogen. Here we show that the combined anti-bacterial and anti-inflammatory properties of the scavenger receptor cysteine-rich (SRCR) protein CD5L contribute to a remarkable therapeutic effect of the protein to fight sepsis, such that when exogenously administered in C57BL/6 mice with induced lethal-grade sepsis, it can be a very effective curative agent to treat this condition. The resistance conferred by CD5L to polybacterial-induced sepsis using the cecal ligation and puncture (CLP) model is consistent with the reported observations that CD5L physically binds and inactivates diverse species and strains of bacteria. Accordingly, our CD5L-knockout mice are significantly more susceptible to experimentally-induced mid-grade CLP than wild-type animals. We show that CD5L is centered on promoting neutrophil recruitment and activation, overall contributing to reducing the bacteria burden of the animals. However, the dramatic susceptibility of CD5L-deficient animals is not necessarily correlated only with pathogen load, as these mice are also extremely susceptible to sterile sepsis induced by nonlethal doses of LPS. Notwithstanding the observed capacity of CD5L to directly bind to a broad range of pathogens, typical of many PRRs, our evidence suggests that the anti-inflammatory properties of the protein are at least as important as its pathogen-binding potential, and can, and should, be explored to treat the deadly inflammation storm that is sepsis.

immunology↗