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Biology subjects

Bovolenta, E. R.

Publications and source records attributed to Bovolenta, E. R..

3 recordsLinked to original sources

EpiFlow: multidimensional single-cell epigenetic profiling by spectral flow cytometry

The epigenetic landscape of individual cells determines their identity and function, yet current methods for profiling chromatin modifications at single-cell resolution remain low-throughput, costly, or limited in parametric depth. Here we present EpiFlow, a spectral flow cytometry-based platform that enables the simultaneous quantification of 16 epigenetic markers, including histone post-translational modifications, DNA methylation, and hydroxymethylation, at the single-cell level. We demonstrate that EpiFlow is robust across species from yeast to mammals and resolves biologically meaningful epigenetic transitions during the cell cycle, stem cell differentiation, germinal centre B cell maturation, diabetic liver remodelling, and seizure-induced chromatin reprogramming. High-dimensional integration of EpiFlow data enables cell-type classification based solely on epigenetic profiles in liver, brain, blood, and cancer. Furthermore, EpiFlow detects on-target and off-target/indirect effects of epigenetic drugs in a high-throughput-compatible format. Collectively, these results establish EpiFlow as a broadly applicable platform for single-cell epigenetic analysis in basic, pharmaceutical, and translational research.

cell biology↗

Pre-TCR signaling intensity shapes the TCRβ repertoire

Signaling via pre-TCR is essential for initial T cell differentiation. How the signal is triggered and whether its alteration impacts on lymphocyte repertoires is nevertheless debated. We show that a mutation in the transmembrane domain of the CD3{zeta} chain impairs murine thymocyte development at the double negative (DN) stage coinciding with reduced levels of steady-state pre-TCR signaling. Single particle tracking and TIRF microscopy on mouse primary DN3/DN4 thymocytes shows that wild-type pre-TCR form particles with a broad range of fluorescent intensities whereas mutant complexes are less intensely labeled and move faster, suggesting reduced pre-TCR nanoclustering. Notably, the mutant early-pre-TCR-selected-DP population shows less TCR{beta} repertoire diversity. We thus propose that the pre-TCR forms stable nanoclusters, the size of which determines signaling efficacy. This signaling does not merely promote maturation of any thymocyte expressing a rearranged TCR{beta} chain, but shapes the repertoire of DP thymocytes that can audition for positive and negative selection.

immunology↗

Recreation of an antigen-driven germinal center in vitro by providing B cells with phagocytic antigen

Successful vaccines rely on activating a functional humoral response that results from generating class-switched high affinity immunoglobulins (Igs) with a superior capacity to neutralize infection. Key to this process is the germinal center (GC) reaction, in which B cells are selected in their search for antigen and T cell help. A major hurdle to understanding the mechanisms of B cell:T cell cooperation has been the lack of an in vitro system to recreate GCs in an antigen-specific manner. Here we report the generation of functional antigen-specific high affinity Igs of different isotypes in simple 2-cell type cultures of naive B and T cells. It is crucial for this process for B cells to take up antigen by a phagocytic mechanism, which results in stronger and more sustained BCR signals compared to stimulation with a soluble antigen. We also show the applicability of the system to generate antibodies of potential clinical interest.

immunology↗