Biology subjects

Bahena, A.

Publications and source records attributed to Bahena, A..

3 recordsLinked to original sources

bioRxiv2026

Rapid receptor internalization potentiates CD7-targeted lipid nanoparticles for efficient mRNA delivery to T cells and in vivo CAR T-cell engineering

Targeted lipid nanoparticles (tLNPs) enable efficient mRNA delivery to T cells, allowing for in situ generation of chimeric antigen receptor (CAR) T cells without ex vivo manipulation. This strategy has shown promising therapeutical efficacy in preclinical studies of cardiac fibrosis, cancer, and autoimmune diseases. While multiple T-cell surface receptors have been targeted across studies for tLNP-mediated in vivo CAR T-cell generation and exhibit diverse efficiencies, their comparative performance and the mechanisms underlying these differences remain unclear. Here, we systematically compared tLNPs with antibody-based moieties targeting T-cell receptors including CD2, CD4, CD5, CD7, CD8, or a CD4/8 dual-targeting combination under identical conditions, assessing their mRNA delivery efficiency in human T cells and PBMCs in vitro, and subsequently validating the best performer in vivo in humanized mice. Among all moieties tested, CD7-targeting tLNPs achieved the highest mRNA delivery to T cells and efficiently generated functional CAR T cells in vivo. Mechanistic analysis revealed that receptor internalization, rather than the receptor abundance, is the primary determinant of delivery efficiency, a property intrinsic to each receptor and largely independent of antibody clone. These findings provide a rational framework for selecting optimal targeting moiety to enable highly efficient in vivo CAR T-cell engineering. HighlightsO_LITargeting CD7 outperforms other receptors for tLNP-mRNA delivery to T cells C_LIO_LIReceptor abundance does not predict tLNP-mRNA delivery efficiency C_LIO_LIReceptor internalization kinetics governs tLNP-mRNA delivery efficiency C_LIO_LICD7-targeting LNP-mRNA enables efficient in vivo CAR T-cell engineering C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=90 SRC="FIGDIR/small/701374v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@9c2c4eorg.highwire.dtl.DTLVardef@120ced7org.highwire.dtl.DTLVardef@eb9b5forg.highwire.dtl.DTLVardef@25b6f7_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2025

Postmortem brain MRI reveals differential associations of subcortical and limbic volumes with cortical thinning and neuropathology patterns

Structured AbstractO_ST_ABSIntroductionC_ST_ABSThe impact of different neuropathologies on deep brain structures remains to be understood. We examine subcortical and limbic volumetry in neurodegenerative diseases involving p-tau, -synuclein and TDP-43. MethodsWe acquired neuropathological measures and brain segmentations from postmortem analysis of 132 donors with Alzheimers disease (AD), Lewy body disease (LBD), Frontotemporal Lobar Degeneration with TDP-43 (FTLD-TDP) and FTLD-Tau. ResultsLBD had the least subcortical, limbic and cortical atrophy compared to AD, FTLD-TDP and FTLD-Tau. In donors with both AD and LBD pathologies, primary LBD was associated with less atrophy than primary AD. While AD had cortico-subcortical and cortico-limbic morphometric associations, LBD had more limited parieto-occipital cortico-limbic associations. FTLD-TDP had cortico-subcortical while FTLD-Tau had cortico-subcortical and cortico-limbic associations. In AD and FTLD-Tau, hippocampal volumes correlated with p-tau burden, neuron loss and gliosis. In LBD, thalamic -synuclein severity was associated with subcortical/limbic volumes. DiscussionPostmortem neuroimaging reveals disease- and region-specific structure-pathology relationships.

neuroscience↗

bioRxiv2025

Characterization of hippocampal subfields using histology-based annotated postmortem MRI: Lessons for in vivo segmentation II

High-resolution in vivo magnetic resonance imaging (MRI) of hippocampal subfields is a rapidly advancing field due to their implication in cognition, disorder, and disease. Hippocampal subfield segmentation on in vivo MRI is generally guided by postmortem reference material, which has been limited by small sample sizes that preclude comprehensive characterization of subfield border locations and their variability. Addressing this, we characterized hippocampal subfield border variability in two ultra-high-resolution postmortem MRI datasets with combined annotated histological sections, including cases with and without dementia. We examined: 1) the order of appearance and disappearance of subfields along the long axis of the hippocampus; 2) the order of appearance and disappearance of subicular subregions; 3) the medial-lateral position of subicular subregional boundaries along the hippocampal body; 4) the location of the CA3 relative to hippocampal head digitations; 5) the subfield borders in the hippocampal body relative to a volume proportion of the dark band; and 6) the association of hippocampal length and subiculum-CA1 border location with diagnosis, demographic factors, and factors related to postmortem imaging. Our findings reaffirmed that there is a consistent order of appearance and disappearance of subfields in the hippocampal head and tail, respectively. The subicular subregions exhibited a first in, last out order of appearance and disappearance, and pre/parasubiculum consistently occupied half of the subicular complex in coronal slices throughout the hippocampal body. Hippocampal head digitations were not a reliable landmark for CA3 appearance, but SRLM proportionality did offer a potentially consistent approach for estimating CA2 and CA3 subfield borders in relation to the hippocampal border. No clear relationship was found between the anatomical features and diagnosis, demographic factors, and factors related to postmortem imaging. These findings have implications for the development and harmonization of hippocampal subfield segmentation protocols and interpretation of high-resolution functional MRI studies of the human hippocampus.

neuroscience↗