Biology subjects

Boland, B.

Publications and source records attributed to Boland, B..

8 recordsLinked to original sources

bioRxiv2026

Stromal state plasticity defines risk and therapeutic opportunity in recalcitrant inflammatory bowel disease

Inflammatory bowel diseases (IBD) remain a relapsing, treatment-refractory disorder marked by progressive tissue injury and inflammation despite expanding immune-targeted therapies. We established a prospective cohort integrating stromal biobanking, functional phenotyping, cross-cohort benchmarking, and outcome modeling to define disease-anchored cellular states. Colonic myofibroblasts from 34 individuals spanning health, ulcerative colitis, and Crohns disease resolved into two dominant states: inflammatory (IMFs) and quiescent (QMFs) myofibroblasts. QMF predominance forecasted remission, whereas IMF predominance increased the odds of worsening endoscopic severity despite therapy escalation during follow-up by [~]4.6-fold, linking early stromal biology to clinical outcomes. Unlike QMFs, IMFs exhibited a senescence-associated secretory phenotype that impaired epithelial stemness, barrier integrity, and innate immune fitness. State-guided prioritization identified EDNRB-antagonism as a high-confidence stromal intervention, reversing pathogenic phenotypes across orthogonal assays and species. Outcome simulation positioned stromal-state reversibility by EDNRB-antagonism as a precision axis, reducing odds of recalcitrance by [~]96.4% and reframing treatment resistance as a reversible stromal state. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=185 HEIGHT=200 SRC="FIGDIR/small/720931v2_ufig1.gif" ALT="Figure 1"> View larger version (88K): org.highwire.dtl.DTLVardef@3b2c50org.highwire.dtl.DTLVardef@da5400org.highwire.dtl.DTLVardef@1c100c1org.highwire.dtl.DTLVardef@1882e1_HPS_FORMAT_FIGEXP M_FIG C_FIG In this work, Tindle et al. identify reversible stromal states that govern remission vs. recalcitrant outcomes in IBD and nominate precision reprogramming of pathogenic myofibroblasts as a new therapeutic strategy.

physiology↗

bioRxiv2024

Atrial Granules in Atrial Cardiomyocytes as Acidic Calcium Stores

Acidic calcium stores significantly influence basal calcium transient amplitude and {beta}-adrenergic responses in cardiomyocytes. Atrial myocytes express a small acidic organelle called atrial granules (AG), which store and excrete atrial natriuretic peptide and are not expressed by healthy ventricular myocytes. AG are known to be acidic with a high calcium content. The number and position of these calcium-rich organelles relative to other signaling sites has not been investigated. Staining of acidic organelles in adult guinea pig cardiomyocytes showed the presence of fluorescent acidic puncta throughout the cytosol. Atrial myocytes exhibited an increased concentration of acidic organelles at the nuclear poles. Live cell fluorescent studies using PBA to inhibit peptidylglycine -amidating monooxygenase, a crucial component of AG membranes, effectively eliminated staining at the nuclear poles and most acidic puncta in atrial cells. The application of PBA to ventricular myocytes did not affect LysoTracker staining. Electron microscopy studies on goat atrial fibrillation (AF) and sham control tissue, allowed visualization of AGs. Quantitative analysis revealed AGs to be in close apposition to the sarcoplasmic reticulum and mitochondria. AGs were significantly increased in AF goat samples when compared to sinus rhythm from 3D electron tomography images. Our imaging studies suggest that AGs make up a large percentage of atrial acidic stores, with AG associated with the sarcoplasmic reticulum and their number increasing during AF. We raise the question whether the positioning of AGs are strategic to communicate with other calcium organelles. Further studies to investigate whether AGs contribute to physiological calcium signalling are required.

physiology↗

bioRxiv2024

Functional Diversity of Memory CD8 T Cells is Spatiotemporally Imprinted

Tissue-resident memory CD8 T cells (TRM) kill infected cells and recruit additional immune cells to limit pathogen invasion at barrier sites. Small intestinal (SI) TRM cells consist of distinct subpopulations with higher expression of effector molecules or greater memory potential. We hypothesized that occupancy of diverse anatomical niches imprints these distinct TRM transcriptional programs. We leveraged human samples and a murine model of acute systemic viral infection to profile the location and transcriptome of pathogen-specific TRM cell differentiation at single-transcript resolution. We developed computational approaches to capture cellular locations along three anatomical axes of the small intestine and to visualize the spatiotemporal distribution of cell types and gene expression. TRM populations were spatially segregated: with more effector- and memory-like TRM preferentially localized at the villus tip or crypt, respectively. Modeling ligand-receptor activity revealed patterns of key cellular interactions and cytokine signaling pathways that initiate and maintain TRM differentiation and functional diversity, including different TGF{beta} sources. Alterations in the cellular networks induced by loss of TGF{beta}RII expression revealed a model consistent with TGF{beta} promoting progressive TRM maturation towards the villus tip. Ultimately, we have developed a framework for the study of immune cell interactions with the spectrum of tissue cell types, revealing that T cell location and functional state are fundamentally intertwined.

immunology↗

bioRxiv2023

A Living Organoid Biobank of Crohn's Disease Patients Reveals Molecular Subtypes for Personalized Therapeutics

ABSTRACT (Structured)Crohns disease (CD) is a complex, clinically heterogeneous disease of multifactorial origin; there is no perfect pre-clinical model, little insight into the basis for such heterogeneity, and still no cure. To address these unmet needs, we sought to explore the translational potential of adult stem cell-derived organoids that not only retain their tissue identity, but also their genetic and epigenetic disease-driving traits. We prospectively created a biobank of CD patient-derived organoid cultures (PDOs) using biopsied tissues from colons of 34 consecutive subjects representing all clinical subtypes (Montreal Classification B1-B3 and perianal disease). PDOs were generated also from healthy subjects. Comparative gene expression analyses enabled benchmarking of PDOs as tools for modeling the colonic epithelium in active disease and revealed that despite the clinical heterogeneity there are two major molecular subtypes: immune-deficient infectious-CD [IDICD] and stress and senescence-induced fibrostenotic-CD [S2FCD]. The transcriptome, genome and phenome show a surprising degree of internal consistency within each molecular subtype. The spectrum of morphometric, phenotypic, and functional changes within the "living biobank" reveals distinct differences between the molecular subtypes. These insights enabled drug screens that reversed subtype-specific phenotypes, e.g., impaired microbial clearance in IDICD was reversed using agonists for nuclear receptors, and senescence in S2FCD was rectified using senotherapeutics, but not vice versa. Phenotyped-genotyped CD-PDOs may fill the gap between basic biology and patient trials by enabling pre-clinical Phase 0 human trials for personalized therapeutics. GRAPHIC ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/532245v1_ufig1.gif" ALT="Figure 1"> View larger version (58K): org.highwire.dtl.DTLVardef@1edcea0org.highwire.dtl.DTLVardef@198a3c8org.highwire.dtl.DTLVardef@28d394org.highwire.dtl.DTLVardef@5a9dbb_HPS_FORMAT_FIGEXP M_FIG C_FIG In BriefThis work creates a prospectively biobanked phenotyped-genotyped Crohns disease patient-derived organoids (CD-PDOs) as platforms for molecular subtyping of disease and for ushering personalized therapeutics. HIGHLIGHTSO_LIProspectively biobanked CD-organoids recapitulate the disease epithelium in patients C_LIO_LIThe phenome-transcriptome-genome of CD-organoids converge on two molecular subtypes C_LIO_LIOne subtype shows impaired microbial clearance, another increased cellular senescence C_LIO_LIPhenotyped-genotyped PDOs are then used for integrative and personalized therapeutics C_LI

immunology↗

bioRxiv2023

Compartmentalisation proteomics revealed endolysosomal protein network changes in a goat model of atrial fibrillation

Endolysosomes (EL) are known for their role in regulating both intracellular trafficking and proteostasis. EL help facilitate elimination of damaged membrane and cytosolic proteins, protein aggregates, membranous organelles and also play an important role in calcium signalling. Despite the importance of EL, their specific role in cardiovascular disease is not well understood. In particular, its unclear how EL contribute to atrial pathology over longer time frames. To shed light on this question, we conducted a comprehensive analysis that involved proteomics, transcriptomics, integrated analysis, electron tomography, western blotting, and enzyme assays. To identify the role of EL in atrial fibrillation (AF), we applied a recently published organelle protein isolation method. We used this method to study biopsies from AF goat model and analyse the EL-specific proteins and pathways involved in this condition. Our results revealed the upregulation of the AMPK pathway and the expression of EL-specific proteins that were not found in whole tissue lysates (TL), including GAA, DYNLRB1, CLTB, SIRT3, CCT2, and muscle-specific HSPB2. We also observed structural anomalies, such as autophago-vacuole formation, irregularly shaped mitochondria, and glycogen deposition, which provide insights into the ELs contribution to AF and related pathways and molecular mechanisms. Overall, our findings suggest that EL play an important role in the development of AF over longer time frames, and provide a more detailed understanding of the underlying molecular processes involved.

molecular biology↗

bioRxiv2020

Delineation of a molecularly distinct terminally differentiated memory CD8 T cell population

Memory CD8 T cells provide durable protection against diverse intracellular pathogens and can be broadly segregated into distinct circulating and tissue-resident populations. Paradigmatic studies have demonstrated circulating memory cells can be further divided into effector memory (TO_SCPLOWEMC_SCPLOW) and central memory (TO_SCPLOWCMC_SCPLOW) populations based on discrete functional characteristics. Following resolution of infection, we identified a persisting antigen-specific CD8 T cell population that was simultaneously terminally-fated with potent effector function but maintained memory T cell qualities and conferred robust protection against reinfection. Notably, this terminally-differentiated effector memory CD8 T cell population (terminal-TO_SCPLOWEMC_SCPLOW) was conflated within the conventional TO_SCPLOWEMC_SCPLOW population, prompting redefinition of the classical characteristics of TO_SCPLOWEMC_SCPLOW cells. Murine terminal-TO_SCPLOWEMC_SCPLOW were transcriptionally, functionally, and developmentally unique compared to TO_SCPLOWEMC_SCPLOW cells. Through mass cytometry and single-cell RNAseq analyses of human peripheral blood from healthy individuals, we also identified an analogous terminal-TO_SCPLOWEMC_SCPLOW population of CD8 T cells that was transcriptionally distinct from TO_SCPLOWEMC_SCPLOW and TO_SCPLOWCMC_SCPLOW. A key finding of this study was that parsing of terminal-TO_SCPLOWEMC_SCPLOW from conventionally defined TO_SCPLOWEMC_SCPLOW challenges classical characteristics of TO_SCPLOWEMC_SCPLOW biology, including enhanced presence in lymphoid tissues, robust IL-2 production and recall potential, greater than expected homeostatic fitness, refined transcription factor dependencies, and a distinct molecular phenotype. Classification of terminal-TO_SCPLOWEMC_SCPLOW and clarification of TO_SCPLOWEMC_SCPLOW biology hold broad implications for understanding the molecular regulation of memory cell states and harnessing immunological memory to improve immunotherapies.

immunology↗

bioRxiv2020

Acetyl-Leucine slows disease progression in lysosomal storage disorders

Acetyl-DL-leucine (ADLL) is a derivative of the branched chain amino acid leucine. In observational clinical studies ADLL improved symptoms of ataxia, in particular in patients with the lysosomal storage disorder (LSD), Niemann-Pick disease type C 1 (NPC1). Here, we investigated ADLL and its enantiomers acetyl-L-leucine (ALL) and acetyl-D-leucine (ADL) in symptomatic Npc1-/- mice and observed an improvement in ataxia with both enantiomers and ADLL. When ADLL and ALL were administered pre-symptomatically to Npc1-/- mice, both treatments delayed disease progression and extended life span, whereas ADL did not. These data are consistent with ALL being the neuroprotective enantiomer. Altered glucose and antioxidant metabolism were found to be implicated as one of the potential mechanisms of action of the L enantiomer in Npc1-/- mice. When miglustat and ADLL were used in combination significant synergy resulted. In agreement with these pre-clinical data, when NPC1 patients were evaluated after 12 months of ADLL treatment, rates of disease progression were slowed, with stabilisation or improvement in multiple neurological domains. A beneficial effect of ADLL on gait was also observed in this study in a mouse model of GM2 gangliosidosis (Sandhoff disease) and in Tay-Sachs and Sandhoff disease patients in individual-cases of off-label-use. Taken together, we have identified an unanticipated neuroprotective effect of acetyl-L-leucine and underlying mechanisms of action in LSDs, supporting its further evaluation in clinical trials in lysosomal disorders.

neuroscience↗

bioRxiv2020

Molecular determinants and heterogeneity of tissue-resident memory CD8+ T lymphocytes revealed by single-cell RNA sequencing

During an immune response to microbial infection, CD8+ T cells give rise to distinct classes of cellular progeny that coordinately mediate clearance of the pathogen and provide long-lasting protection against reinfection, including a subset of non-circulating tissue-resident memory (TRM) cells that mediate potent protection within non-lymphoid tissues. Here, we utilized single-cell RNA-sequencing to examine the gene expression patterns of individual CD8+ T cells in the spleen and small intestine intraepithelial lymphocyte (siIEL) compartment throughout the course of their differentiation in response to viral infection. These analyses revealed previously unknown transcriptional heterogeneity within the siIEL CD8+ T cell population at several states of differentiation, representing functionally distinct TRM cell subsets as well as a subset of TRM cell precursors within the tissue early in infection. Taken together, these findings may inform strategies to optimize CD8+ T cell responses to protect against microbial infection and cancer. One sentence summaryHere, we applied single-cell RNA-sequencing to elucidate the gene expression patterns of individual CD8+ T cells differentiating throughout the course of infection in the spleen and small intestinal epithelium, which revealed previously unidentified molecular determinants of tissue-resident T cell differentiation as well as functional heterogeneity within the tissue-resident CD8+ T cell population.

immunology↗