Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies with an overall survival of 5% and is the second cause of death by cancer, mainly linked to its high metastatic aggressiveness. Accordingly, understanding the mechanisms sustaining the PDAC metastatic phenotype remains a priority. In this study, we generated and used a murine in vivo model to select clones from the human Panc-1 PDAC cell line that exhibit a high propensity to seed and metastasize into the liver. We showed that myoferlin, a protein previously reported to be overexpressed in PDAC, is significantly involved in the migratory abilities of the selected cells. We first report that highly metastatic Panc-1 clones expressed a significantly higher myoferlin level than the corresponding low metastatic ones. Using scratch wound and Boyden’s chamber assays, we show that cells expressing a high myoferlin level have higher migratory potential than cells characterized by a low myoferlin abundance. Moreover, we demonstrate that myoferlin silencing leads to a migration decrease associated with a reduction of mitochondrial respiration. Since mitochondrial oxidative phosphorylation has been shown to be implicated in the tumor progression and dissemination, our data identify myoferlin as a valid potential therapeutic target in PDAC.

Branched-chain amino acids (BCAA) are essential amino acids playing crucial roles in protein synthesis and brain neurotransmission. Branched-chain ketoacid dehydrogenase (BCKDH), the flux-generating step of BCAA catabolism, is tightly regulated by reversible phosphorylation of its E1α-subunit. BCKDK is the kinase responsible for the phosphorylation-mediated inactivation of BCKDH. In three siblings with severe developmental delays, microcephaly, autism spectrum disorder and epileptic encephalopathy, we identified a new homozygous in-frame deletion (c.999_1001delCAC; p.Thr334del) of BCKDK. Plasma and cerebrospinal fluid concentrations of BCAA were markedly reduced. Hyperactivity of BCKDH and over-consumption of BCAA were demonstrated by functional tests in cells transfected with the mutant BCKDK. Treatment with pharmacological doses of BCAA allowed the restoring of BCAA concentrations and greatly improved seizure control. Behavioral and developmental skills of the patients improved to a lesser extent. Importantly, a retrospective review of the newborn screening results allowed the identification of a strong decrease in BCAA concentrations on dried blood spots, suggesting that BCKDK is a new treatable metabolic disorder probably amenable to newborn screening programs.

Retroviruses and their host have coevolved in a delicate balance between viral replication and survival of the infected cell. In this equilibrium, restriction factors expressed by infected cells control different steps of retroviral replication such as entry, uncoating, nuclear import, expression, or budding. Here, we describe a mechanism of restriction against human T cell leukemia virus type 1 (HTLV-1) by the helicase-like transcription factor (HLTF). We show that RNA and protein levels of HLTF are reduced in primary T cells of HTLV-1-infected subjects, suggesting a clinical relevance. We further demonstrate that the viral oncogene Tax represses HLTF transcription via the Enhancer of zeste homolog 2 methyltransferase of the Polycomb repressive complex 2. The Tax protein also directly interacts with HLTF and induces its proteasomal degradation. RNA interference and gene transduction in HTLV-1-infected T cells derived from patients indicate that HLTF is a restriction factor. Restoring the normal levels of HLTF expression induces the dispersal of the Golgi apparatus and overproduction of secretory granules. By synergizing with Tax-mediated NF-κB activation, physiologically relevant levels of HLTF intensify the autophagic flux. Increased vesicular trafficking leads to an enlargement of the lysosomes and the production of large vacuoles containing viral particles. HLTF induction in HTLV-1-infected cells significantly increases the percentage of defective virions. In conclusion, HLTF-mediated activation of the autophagic flux blunts the infectious replication cycle of HTLV-1, revealing an original mode of viral restriction.

Multiple myeloma (MM) is an incurable hematologic malignancy arising from clonal plasma cells, with poor long-term outcomes due to inevitable relapse after conventional therapies. Chimeric antigen receptor (CAR) T-cell immunotherapy targeting B-cell maturation antigen (BCMA) has shown remarkable efficacy in relapsed patients. Conventional CARs employ single-chain variable fragments (scFvs), whereas single-domain antibodies (sdAb or VHHs) offer advantages such as small size, high stability, and potentially reduced immunogenicity. We designed and evaluated a novel anti-BCMA nanoCAR-T based on the VHH Nb17, compared with the conventional scFv-based CAR-T CT103a. Nb17 demonstrated strong BCMA binding and was incorporated into a CAR construct. Both nanoCAR-T and CT103a were generated via lentiviral transduction of primary T cells. Their cytotoxicity, cytokine secretion, degranulation, memory phenotype, and gene expression were assessed in vitro, along with antitumor activity in vivo. Nb17-nanoCAR-T demonstrated specific cytotoxicity, cytokine release (IL-2, TFNa, IFNg), and CD107a degranulation comparable to CT103a. Transcriptomic analysis revealed overlapping pathways between both CARs. Upon rechallenge, both CARs showed enhanced proliferation compared with untransduced T cells. In vivo, Nb17-nanoCAR-T and CT103a eradicated tumors in NSG mice. These findings demonstrate Nb17-nanoCAR-T exhibits potent anti-myeloma efficacy comparable to scFv-based CAR-T, supporting its potential as a promising therapeutic alternative.

SARS-CoV2, severe acute respiratory syndrome coronavirus 2, is frequently associated with neurological manifestations. Despite the presence of mild to severe CNS-related symptoms in a cohort of patients, there is no consensus whether the virus can infect directly brain tissue or if the symptoms in patients are a consequence of peripheral infectivity of the virus. Here, we use long-term human stem cell-derived cortical organoids to assess SARS-CoV2 infectivity of brain cells and unravel the cell-type tropism and its downstream pathological effects. Our results show consistent and reproducible low levels of SARS-CoV2 infection of astrocytes, deep projection neurons, upper callosal neurons and inhibitory neurons in 6 months human cortical organoids. Interestingly, astrocytes showed the highest infection rate among all infected cell populations that led to increased presence of reactive states. Further, transcriptomic analysis revealed overall changes in expression of genes related to cell metabolism, astrocyte activation and, inflammation and further, upregulation of cell survival pathways. Thus, local and minor infectivity of SARS-CoV2 in the brain may induce widespread adverse effects and may lead to resilience of dysregulated neurons and astrocytes within an inflammatory environment.

Tanycytes are specialized glial cells lining the third ventricle that sense metabolic cues and contribute to hypothalamic regulation of energy balance. Although their role in nutrient sensing is well established, their contribution to hypothalamic immune regulation remains unclear. Here, we identify tanycytes as key immunomodulatory cells that control thermoregulation by modulating microglial state in the hypothalamus. We show that tanycytes release the pro-resolving immune mediator Annexin A1 (ANXA1) via extracellular vesicles in a nutrient-dependent manner. Tanycyte-derived ANXA1 then modulates microglial morphology, phagocytic activity, and cytokine profiles, thereby influencing thermoregulatory responses. Notably, disruption of tanycytic ANXA1 signaling induces microglial activation and hyperthermia, whereas microglial depletion rescues temperature homeostasis, establishing microglia as essential mediators of this pathway. Together, our findings uncover an immune function for tanycytes and define a tanycyte-microglia axis that links metabolic sensing to hypothalamic thermoregulation.