Biology subjects

Maillard, J.

Publications and source records attributed to Maillard, J..

6 recordsLinked to original sources

bioRxiv2026

Closed, Automated CAR-T Cell Manufacturing: from Research to Point of Care production.

Background: Point-of-care manufacturing of CAR-T cells could reduce cost and improve patient access, but few closed, automated systems support both flexible process development and GMP production. Methods and results: We describe LimCORE, a single-use consumable for cell incubation and processing, implemented in LimGROW (manual system) and LimONE (closed and automated system). In LimGROW, T cells expanded 246 +/-18 fold over 10 days at optimized seeding density, versus 89 +/-9 fold in a G-Rex control, with similar viability (>90%) and phenotype. Process parameters directly transferred to LimONE, where automated, closed buoyancy-based CD3+ selection achieved 90.3 +/-3.5% purity and 59.2 +/-17.0% recovery in under two hours. Using this workflow, we manufactured CD19 CAR-T cells in a fully closed, automated 7-day LimONE process requiring 155 minutes of operator intervention. LimONE manufactured CAR-T cells reached 42.6 +/-2.4 fold expansion (532 +/-29x10e6; cells at harvest), with 43.6 +/-6.0% transduction efficiency and viability similar to G-Rex controls. CD4+/CD8+ ratios, CD8+ differentiation subsets, and cytotoxicity were comparable between platforms, while LimONE-manufactured cells showed increased spare respiratory capacity and oxygen consumption. Across four manufacturing runs on the LimONE, no hardware or software failures occurred, and automated liquid transfers and volume concentration stayed within +/-5% accuracy. Conclusions: These data show that LimCORE supports T cell expansion, selection, and complete CD19 CAR-T manufacturing with performance similar to existing platforms while reducing operator time, across R&D and GMP scale closed-system formats.

bioengineering↗

bioRxiv2024

RoCK and ROI: Single-cell transcriptomics with multiplexed enrichment of selected transcripts and region-specific sequencing

Various tools have been developed to reliably identify, trace and analyze single cells in complex tissues. In recent years, these technologies have been combined with transcriptomic profiling approaches to explore molecular mechanisms that drive development, health, and disease. However, current methods still fall short of profiling single cell transcriptomes comprehensively, with one major challenge being high non-detection rates of specific transcripts and transcript regions. Such information is often crucial to understanding the biology of cells or tissues and includes lowly expressed transcripts, sequence variations and exon junctions. Here, we developed a scRNAseq workflow, RoCK and ROI (Robust Capture of Key transcripts and Regions Of Interest), that tackles these limitations. RoCKseq uses targeted capture to enrich for key transcripts, thereby supporting the detection and identification of cell types and complex phenotypes in scRNAseq experiments. ROIseq directs a subset of reads to a specific region of interest via selective priming to ensure detection. Importantly, RoCK and ROI guarantees efficient retrieval of specific sequence information without compromising overall single cell transcriptome information and our workflow is supported by a novel bioinformatics pipeline to analyze the multimodal information. RoCK and ROI represents a significant enhancement over non-targeted single cell sequencing, particularly when cell categorization depends on transcripts that are missed in standard scRNAseq experiments. In addition, it also allows exploration of biological questions that require assessment of specific sequence elements along the targets to be addressed.

genomics↗

bioRxiv2023

Structure of a membrane-bound menaquinol:organohalide oxidoreductase

Organohalide-respiring bacteria are key organisms for the bioremediation of soils and aquifers contaminated with halogenated organic compounds. The major players in this process are respiratory reductive dehalogenases, corrinoid enzymes that use organohalides as substrates and contribute to energy conservation. Here, we present the first structure of a functional menaquinol:organohalide oxidoreductase (MOOR) obtained by cryo-EM. The membrane-bound protein was isolated from Desulfitobacterium hafniense strain TCE1 as a PceA2B2 complex catalysing the dechlorination of tetrachloroethene (PCE). Two catalytic PceA subunits are anchored to the membrane by two small integral membrane PceB subunits. The structure reveals two menaquinone molecules bound at the interface of the two different subunits, which are the starting point of a chain of redox cofactors for electron transfer to the active site. This structure elucidates how energy is conserved during organohalide respiration in menaquinone-dependent organohalide-respiring bacteria.

microbiology↗

bioRxiv2021

EEG microstate dynamics indicate a U-shaped path to propofol-induced loss of consciousness

It is commonly believed that the stream of consciousness is not continuous but parsed into transient brain states manifesting themselves as discrete spatiotemporal patterns of global neuronal activity. Electroencephalographical (EEG) microstates are proposed as the neurophysiological correlates of these transiently stable brain states that last for fractions of seconds. To further understand the link between EEG microstate dynamics and consciousness, we continuously recorded high-density EEG in 23 surgical patients from their awake state to unconsciousness, induced by step-wise increasing concentrations of the intravenous anesthetic propofol. Besides the conventional parameters of microstate dynamics, we introduce a new method that estimates the complexity of microstate sequences. The brain activity under the surgical anesthesia showed a decreased sequence complexity of the stereotypical microstates, which became sparser and longer-lasting. However, we observed an initial increase in microstates temporal dynamics and complexity with increasing depth of sedation leading to a distinctive "U-shape" that may be linked to the paradoxical excitation induced by moderate levels of propofol. Our results support the idea that the brain is in a metastable state under normal conditions, balancing between order and chaos in order to flexibly switch from one state to another. The temporal dynamics of EEG microstates indicate changes of this critical balance between stability and transition that lead to altered states of consciousness. HighlightsO_LIEEG microstates capture discrete spatiotemporal patterns of global neuronal activity C_LIO_LIWe studied their temporal dynamics in relation to different states of consciousness C_LIO_LIWe introduce a new method to estimate the complexity of microstates sequences C_LIO_LIWith moderate sedation complexity increases then decreases with full sedation C_LIO_LIComplexity of microstate sequences is sensitive to altered states of consciousness C_LI

neuroscience↗

bioRxiv2020

Defective Autophagy in Sf1 Neurons Perturbs the Metabolic Response to Fasting and Causes Mitochondrial Dysfunction

ObjectiveThe ventromedial nucleus of the hypothalamus (VMH) is a critical component of the forebrain pathways that regulate energy homeostasis. It also plays an important role in the metabolic response to fasting. However, the mechanisms contributing to these physiological processes remain elusive. Autophagy is an evolutionarily conserved mechanism that maintains cellular homeostasis by turning over cellular components and providing nutrients to the cells during starvation. Here we investigated the importance of the autophagy-related gene Atg7 in Sf1-expressing neurons of the VMH in control and fasted conditions. MethodsWe generated Sf1-Cre; Atg7loxP/loxP mice and examined their metabolic and cellular response to fasting. ResultsFasting induces autophagy in the VMH, and mice lacking Atg7 in Sf1-expressing neurons display altered regulation in glucose and leptin homeostasis and impaired energy expenditure regulation in response to fasting. Moreover, loss of Atg7 in Sf1 neurons causes alterations in the central response to fasting. Furthermore, alterations in mitochondria morphology and activity are observed in mutant mice. ConclusionTogether, these data show that autophagy is nutritionally regulated in VMH neurons and that VMH autophagy participates in the control of energy homeostasis during fasting.

neuroscience↗

bioRxiv2018

Dicer-miR-103/107 controls developmental switch of POMC progenitors into NPY neurons and impacts glucose homeostasis

Proopiomelanocortin (POMC) neurons are major negative regulators of energy balance. A distinct developmental property of POMC neurons is that they can adopt an orexigenic neuropeptide Y (NPY) phenotype. However, the mechanisms underlying the differentiation of Pomc progenitors remain unknown. Here, we show that the loss of the microRNA (miRNA)- processing enzyme Dicer in POMC neurons causes metabolic defects, an age-dependent decline in the number of Pomc mRNA-expressing cells, and an increased proportion of Pomc progenitors acquiring a NPY phenotype. miRNome microarray screening further identified miR-103/107 as candidates that may be involved in the maturation of Pomc progenitors. In vitro inhibition of miR-103/107 causes a reduction in the number of Pomc-expressing cells and increases the proportion of Pomc progenitors differentiating into NPY neurons. Moreover, in utero silencing of miR-103/107 causes perturbations in glucose homeostasis. Together, these data suggest a role for prenatal miR-103/107 in the maturation of Pomc progenitors and glucose homeostasis.

neuroscience↗