Biology subjects

Prieto, M.

Publications and source records attributed to Prieto, M..

7 recordsLinked to original sources

bioRxiv2026

Safety profiling of CAR-T cells using an organotypic human tissue platform

CAR-T-cell-associated on-target off-tumor (OTOT) toxicity represents a major safety concern, as recognition of target antigens on healthy tissues can trigger severe and potentially life-threatening complications. Predicting OTOT toxicity remains a challenge because current preclinical models fail to capture the complexity of native human tissues. Here, we developed a human organotypic tissue platform that enables functional assessment of CAR-T-cell activity in intact human tissues across organ-specific and inflammatory contexts. Using a panel of clinically relevant CAR-T-cell products with known OTOT toxicities, we demonstrate that the platform faithfully recapitulates clinically observed tissue-specific toxicity profiles. CAR-T cells targeting EGFR, HER2, and mesothelin induced inflammatory and cytotoxic responses in healthy human lung tissue, whereas CD19 CAR-T cells remained inactive. We further show that OTOT toxicity cannot be reliably predicted from antigen abundance alone but instead results from the integration of multiple target-dependent determinants, including CAR affinity, inflammatory context, antigen accessibility, and effector-cell dose. The platform also enables quantitative assessment of inflammatory and cytotoxic responses and supports evaluation of pharmacological and CAR design-based strategies to mitigate toxicity. Together, this work establishes the first human organotypic platform for functional modeling of CAR-T-cell-associated OTOT toxicity, providing a clinically relevant framework for preclinical safety evaluation and the rational development of safer engineered cell therapies. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=167 SRC="FIGDIR/small/740527v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@12c8addorg.highwire.dtl.DTLVardef@150d392org.highwire.dtl.DTLVardef@17218f7org.highwire.dtl.DTLVardef@1c54078_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2025

Lipid Composition Controls the Huntingtin Exon1 Membrane-Association and Differentially Modulates its Flanking Regions Dynamics

The pathological expansion of the polyglutamine (polyQ) repeat within the first exon of huntingtin (Httex1) protein is a defining hallmark of Huntingtons disease (HD). Multiple evidence supports that the membrane recruitment of Httex1 is critical for its self-assembly and related toxicity in HD. In this work, we quantitatively examined the early steps of monomeric Httex1(23Q) association with lipid membranes and its impact on the conformational dynamics of the adjacent polyQ regions - the N-terminal N17 segment and C-terminal proline-rich region (PRR). A broad range of membrane physical properties was explored, including zwitterionic and anionic lipids, and also co-existing liquid-ordered and liquid-disordered phases. Two single cysteine mutants were engineered at the N- and C-termini of Httex1(23Q) and fluorescently-labeled with acrylodan or Atto 488 to probe their local polarity and flexibility, respectively. Our results indicate that Httex1- 23Q preferentially binds to negatively-charged lipid vesicles, and to a lower extent to liquid ordered/disordered phases. The N-terminal N17 segment inserts deeply into anionic membranes, adopting a less flexible state than in aqueous solution. At variance, the C-terminal PRR remains highly dynamic and solvent exposed in the Httex1-23Q membrane-bound state, preserving its intrinsic disordered features across all lipid compositions used. Altogether, our work provides unique insight into the distinct roles of each flanking polyQ region in mediating httex1-lipid binding, and how the lipid composition further modulates these early interaction steps.

biophysics↗

bioRxiv2025

Ceramide Connects TNF-α Signaling to Organelle Biophysical Remodeling

Ceramides are essential bioactive lipids involved in cell physiology and stress responses, yet the mechanisms linking their biophysical effects on membranes to downstream cellular outcomes remain incompletely understood. Here, we demonstrate that endogenous ceramide generation in response to TNF--induced stress results in the rapid remodeling of the plasma membrane, triggering a cascade of cellular events. Ceramide accumulation increases membrane order and drives the formation of internalizing vesicles enriched in ceramides, which traffic through the endolysosomal system. These vesicles act as carriers that transmit membrane remodeling signals to intracellular compartments, altering their biophysical properties and function. In parallel, ceramide production reprograms lipid droplet metabolism, decreasing polarity and modifying gene expression related to lipid storage. Our findings provide direct evidence that ceramides function as biophysical integrators of the TNF- stress response, coupling membrane order, vesicle trafficking, and lipid metabolic adaptation. This work reveals how localized lipid remodeling at the plasma membrane propagates intracellularly to support cellular adaptation and homeostasis under inflammatory stress.

biophysics↗

bioRxiv2022

Rapid and accurate identification of Escherichia coli STEC O157:H7 by mass spectrometry, artificial intelligence and detection of specific biomarkers peaks.

The different pathotypes of Escherichia can produce a large number of human diseases. Surveillance becomes complex since their differentiation are not easy. Particularly, the detection of Shiga toxin-producing Escherichia coli (STEC) serotype O157:H7 consists of stool culture of a diarrheal sample in enrichment and/or selective media, identification of presumptive colonies and confirmation by Multiplex PCR technique for the genotypic characterization of serogroup O157 and Shiga toxins (stx1 and stx2), in addition to the traditional biochemical identification. All of these procedures are laborious, require a certain level of training, are time consuming and expensive. Among the currently most widely used methodologies, MALDI-TOF MS mass spectrometry (matrix-assisted laser desorption/ionization with time-of-flight mass detection), allows a quick and easy way to obtain a protein spectrum of a microorganism, not only in order to identify the genus and species, but also the discovery of potential biomarker peaks of a certain characteristic. In the present work, the information obtained from 60 clinical isolates was used to detect peptide fingerprints of STEC O157:H7 and other diarrheagenic E. coli. The differences found in the protein profiles of the different pathotypes established the foundations for the development and evaluation of classification models through automated training. The application of the Biomarkers in combination with the predictive models on a new set of samples (n=142), achieved 99.3% of correct classifications, allowing the distinction between STEC O157:H7 isolates from the other diarrheal Escherichia coli. Therefore, given that STEC O157:H7 is the main causal agent of haemolytic uremic syndrome and based on the performance values obtained in the present work (Sensitivity=98.5% and Specificity=100%), this development could be a useful tool for diagnosis of the disease in clinical microbiology laboratories.

microbiology↗

bioRxiv2020

Plasma mass spectrometry fingerprints induced by bacterial endotoxins in murine models as markers of pathophysiological evolution in sepsis

Sepsis has been called "the graveyard of pharmaceutical companies" due to the numerous failed clinical trials. The lack of tools to monitor the immunological status in sepsis constrains the development of immunomodulatory therapies. Here, we evaluated a test based on whole plasma peptidome acquired in a MALDI-TOF-mass spectrometer used for bacterial biotyping and machine-learning algorithms to discriminate the different immunological phases of sepsis. In this proof of concept study, two discrete lipopolysaccharide-(LPS) induced murine models emulating the pro- and anti-inflammatory phases that occur during sepsis were evaluated. The LPS group was inoculated with a single high dose of LPS, recalling the proinflammatory phase, and the IS groups was subjected to increasing doses of LPS to induce the anti-inflammatory/immunosuppression phase. Unstimulated mice served as controls. Both experimental groups showed the hallmarks of pro- and anti- inflammatory phases respectively; the LPS group showed leukopenia and higher levels of cytokines and tissue damage markers, and the IS group showed neutrophilia, lymphopenia and significantly lower antibody titers upon immunization. Principal component analysis of the plasma peptidomes formed three discrete clusters that mostly coincided with the experimental groups. In addition, machine-learning algorithms discriminated the different experimental groups with a sensitivity and specificity of up to 95.7% and 90.9% respectively. Our data reveal the potential of plasma peptidome analysis by MALDI-TOF-mass spectrometry as a simple, speedy and readily transferrable method for sepsis patient stratification that would contribute to therapeutic decision-making based on their immunological status.

immunology↗

bioRxiv2020

Abnormal AMPAR-mediated synaptic plasticity, cognitive and autistic-like behaviors in a missense Fmr1 mutant mouse model of Fragile X syndrome

Fragile X syndrome (FXS) is the most frequent form of inherited intellectual disability and the best-described monogenic cause of autism. FXS is usually caused by a CGG-repeat expansion in the FMR1 gene leading to its silencing and the loss-of-expression of the Fragile X Mental Retardation Protein (FMRP). Missense mutations were also identified in FXS patients, including the recurrent FMRP-R138Q mutation. To investigate the mechanisms underlying FXS in these patients, we generated a knock-in mouse model (Fmr1R138Q) expressing the FMRP-R138Q protein. We demonstrate that the Fmr1R138Q hippocampus has an increased spine density associated with postsynaptic ultrastructural defects and increased AMPA receptor surface expression. Combining biochemical assays, high-resolution imaging and electrophysiological recordings, we also show that the mutation impairs the hippocampal long-term potentiation (LTP) and leads to socio-cognitive deficits in Fmr1R138Q mice. These findings reveal that the R138Q mutation impacts the synaptic functions of FMRP and highlight potential mechanisms causing FXS in FMRP-R138Q patients.

neuroscience↗

bioRxiv2018

Evaluating FAIR-Compliance Through an Objective, Automated, Community-Governed Framework

With the increased adoption of the FAIR Principles, a wide range of stakeholders, from scientists to publishers, funding agencies and policy makers, are seeking ways to transparently evaluate resource FAIRness. We describe the FAIR Evaluator, a software infrastructure to register and execute tests of compliance with the recently published FAIR Metrics. The Evaluator enables digital resources to be assessed objectively and transparently. We illustrate its application to three widely used generalist repositories - Dataverse, Dryad, and Zenodo - and report their feedback. Evaluations allow communities to select relevant Metric subsets to deliver FAIRness measurements in diverse and specialized applications. Evaluations are executed in a semi-automated manner through Web Forms filled-in by a user, or through a JSON-based API. A comparison of manual vs automated evaluation reveals that automated evaluations are generally stricter, resulting in lower, though more accurate, FAIRness scores. Finally, we highlight the need for enhanced infrastructure such as standards registries, like FAIRsharing, as well as additional community involvement in domain-specific data infrastructure creation.

scientific communication and education↗