Biology subjects

Anguera, M.

Publications and source records attributed to Anguera, M..

8 recordsLinked to original sources

bioRxiv2026

Deep immune profiling of the peripheral blood reveals disease- and sex-associated immune cell signatures in patients with systemic sclerosis

ObjectiveSystemic sclerosis (SSc) predominantly affects females but exhibits greater disease severity in males, suggesting sex differences underlying SSc pathogenesis. We sought to define sex-associated alterations in the peripheral immune landscape of patients with SSc. MethodsWe performed high-dimensional immune profiling of PBMCs from 37 healthy donors (68% female) and 37 patients with SSc (11 limited, 26 diffuse; 68% female) using 30-color spectral flow cytometry, quantifying 56 immune cell subsets per donor. We conducted sex-stratified comparisons and correlation analysis, and used principal component analysis followed by linear discriminant analysis to derive a sex-discriminant immune cellular module. ResultsDiffuse cutaneous SSc (dcSSc) was associated with a distinct immune landscape characterized by increased monocyte and decreased natural killer-like and B cell frequencies, suggesting a myeloid-skewed peripheral immunophenotype. Males exhibited greater enrichment of innate immune subsets, including monocyte and dendritic cell subsets, while females exhibited greater enrichment of adaptive immune subsets. Among T cells, dcSSc was associated with coordinated remodeling across CD4+ and CD8+ subsets, including expansion of stem cell memory T cells (Tscm), and increased regulatory T cells, Th17 skewing, and decreased effector-memory CD8+ subsets. Females exhibited greater proportions of naive- and Tscm, and males exhibited higher proportions of effector-memory subsets. Integrating these data, we identified a sex-discriminant immune module comprised of 20 cell types that distinguishes males and females with dcSSc. ConclusionsSSc is associated with sex-specific differences in the peripheral immune landscape. A sex-associated immune program, further amplified in disease, may contribute to the paradox of female-biased susceptibility and male-biased severity in SSc.

immunology↗

bioRxiv2025

Tissue-Specific and NF-kappaB-Independent Xist RNA Localization Patterns in Female Intestinal, Blood, and Muscle Progenitors

X-Chromosome Inactivation (XCI), driven by the expression of Xist RNA and the enrichment of various repressive epigenetic marks, results in the formation of a mostly inactive X chromosome (Xi) to equalize X-linked gene expression between sexes. Unexpectedly, in unstimulated female lymphocytes that are largely quiescent, these epigenetic features are largely absent but are restored by NF-{kappa}B signaling following their activation. To determine whether these epigenetic phenotypes correlate with quiescence or NF-{kappa}B activation in other tissues, we evaluated female progenitor and stem cells from intestine, blood, and muscle. Despite known NF-{kappa}B activation, intestinal progenitors have variable Xist RNA patterns, whereas blood progenitors and neutrophils show a strong correlation between NF-{kappa}B activation status and Xist RNA localization. In contrast, muscle satellite cells (SCs) and myoblasts exhibit Xist RNA accumulation at the Xi without NF-{kappa}B activation. Xist RNA localization patterns in SCs change with age, yet adult SCs have an Xi that is mostly transcriptionally silent while allowing expression of muscle-specific X-linked genes including Dmd. These findings reveal that female somatic cells employ diverse, tissue-specific epigenetic mechanisms to maintain X chromosome inactivation, enabling cell type specific Xi gene expression while preserving chromosome-wide silencing.

genetics↗

bioRxiv2025

B cell stimulation changes the structure and higher-order organization of the inactive X chromosome

X Chromosome Inactivation (XCI) equalizes X-linked gene expression between sexes. B cells exhibit dynamic XCI, with Xist RNA/heterochromatic marks absent on the inactive X (Xi) in naive B cells but returning following mitogenic stimulation. The impact of dynamic XCI on Xi structure and maintenance was previously unknown. Here, we find dosage compensation of the Xi with state-specific XCI escape genes in naive and in vitro activated B cells. Allele-specific OligoPaints indicate similar Xi and Xa territories in B cells that are less compact than in fibroblasts. Allele-specific Hi-C reveals a lack of TAD-like structures on the Xi of naive B cells, and stimulation-induced alterations in TAD-like boundary strength independent of gene expression. Notably, Xist deletion in B cells changes TAD boundaries and large-scale Xi compaction. Altogether, our results uncover B cell-specific Xi plasticity which could underlie sex-biased biological mechanisms.

genetics↗

bioRxiv2025

Xist RNA Dependent and Independent Mechanisms Regulate Dynamic X Chromosome Inactivation in B Lymphocytes

X-Chromosome Inactivation (XCI) involves epigenetic pathways to equalize X-linked gene expression between female and male mammals. XCI is dynamic in female B cells, as cytological enrichment of Xist RNA and heterochromatic marks on the inactive X-chromosome (Xi) are absent in naive B cells yet return following mitogenic stimulation. Here, we asked whether any heterochromatic histone marks are present on the Xi in naive B cells, and whether Xist RNA is required for their deposition and retention following stimulation. We find that the Xi in naive B cells is depleted for H2AK119Ub and H3K9me3 but enriched for DNA methylation and H3K27me3, which maintain an Xist RNA-dependent epigenetic memory of XCI. Upon stimulation, Xist-independent H3K27me3 and Xist-dependent H2AK119Ub modifications accumulate across the Xi with temporal and spatial specificity. Our findings reveal the importance of Xist RNA, H3K27me3, and H2AK119Ub marks for the epigenetic integrity of X-linked genes across the Xi following female B cell stimulation.

genetics↗

bioRxiv2024

Xist Deletion in B Cells Results in Systemic Lupus Erythematosus Phenotypes

Systemic lupus erythematosus (SLE) is an autoimmune disease preferentially observed in females. X-linked gene expression in XX females is normalized to that of XY males by X-Chromosome Inactivation (XCI). However, B cells from female SLE patients and mouse models of SLE exhibit mislocalization of Xist RNA, a critical regulator of XCI, and aberrant expression of X-linked genes, suggesting that impairment of XCI may contribute to disease. Here, we find that a subset of female mice harboring a conditional deletion of Xist in B cells ("Xist cKO") spontaneously develop SLE phenotypes, including expanded activated B cell subsets, disease-specific autoantibodies, and glomerulonephritis. Moreover, pristane-induced SLE-like disease is more severe in Xist cKO mice. Activated B cells from Xist cKO mice with SLE phenotypes have increased expression of proinflammatory X-linked genes implicated in SLE. Together, this work indicates that impaired XCI maintenance in B cells directly contributes to the female-bias of SLE.

immunology↗

bioRxiv2024

NF-κB Signaling is Required for X-Chromosome Inactivation Maintenance Following T cell Activation

X Chromosome Inactivation (XCI) is a female-specific process which balances X-linked gene dosage between sexes. Unstimulated T cells lack cytological enrichment of Xist RNA and heterochromatic modifications on the inactive X chromosome (Xi), and these modifications become enriched at the Xi after cell stimulation. Here, we examined allele-specific gene expression and the epigenomic profiles of the Xi following T cell stimulation. We found that the Xi in unstimulated T cells is largely dosage compensated and is enriched with the repressive H3K27me3 modification, but not the H2AK119-ubiquitin (Ub) mark, even at promoters of XCI escape genes. Upon CD3/CD28-mediated T cell stimulation, the Xi accumulates H2AK119-Ub and H3K27me3 across the Xi. Next, we examined the T cell signaling pathways responsible for Xist RNA localization to the Xi and found that T cell receptor (TCR) engagement, specifically NF-{kappa}B signaling downstream of TCR, is required. Disruption of NF-{kappa}B signaling, using inhibitors or genetic deletions, in mice and patients with immunodeficiencies prevents Xist/XIST RNA accumulation at the Xi and alters expression of some X-linked genes. Our findings reveal a novel connection between NF-{kappa}B signaling pathways which impact XCI maintenance in female T cells.

immunology↗

bioRxiv2022

Remodeling and compaction of the inactive X is regulated by Xist during female B cell activation

X Chromosome Inactivation (XCI) equalizes X-linked gene expression between sexes. B cells exhibit unusually dynamic XCI, as Xist RNA/heterochromatic marks on the inactive X (Xi) are absent in naive B cells, but return following mitogenic stimulation. Xi gene expression analysis supports dosage compensation, but reveals high levels of XCI escape genes in both naive and activated B cells. Allele-specific OligoPaints indicate similar Xi and Xa territories in B cells that is less compact than in fibroblasts. Allele-specific Hi-C maps reveal a lack of TAD-like structures on the Xi of naive B cells, and alterations in TADs and stronger TAD boundaries at Xi escape genes after mitogenic stimulation. Notably, Xist deletion in B cells reduces Xi compaction and changes TAD boundaries, independent of its localization to the Xi. Our findings provide the first evidence that Xi compaction/small scale organization in lymphocytes impact XCI maintenance and female biased X-linked gene expression.

genetics↗

bioRxiv2020

The dynamic epigenetic regulation of the inactive X chromosome in healthy human B cells is dysregulated in lupus patients

Systemic lupus erythematous (SLE) is a female-predominant disease characterized by autoimmune B cells and pathogenic autoantibody production. Individuals with two or more X chromosomes are at increased risk for SLE, suggesting that X-linked genes contribute to the observed sex-bias of this disease. To normalize X-linked gene expression between sexes, one X in female cells is randomly selected for transcriptional silencing through X-Chromosome Inactivation (XCI), resulting in allele-specific enrichment of epigenetic modifications, including histone methylation and the long noncoding RNA XIST/Xist on the inactive X (Xi). As we have previously shown that epigenetic regulation of the Xi in female lymphocytes from mice is unexpectedly dynamic, we used RNA FISH and immunofluorescence to profile epigenetic features of the Xi at the single cell level in human B cell subsets from pediatric and adult SLE patients and healthy controls. Our data reveal that abnormal XCI maintenance in B cells is a feature of SLE. Using single-cell and bulk cell RNA sequencing datasets, we found that novel X-linked immunity genes escape XCI in specific healthy human B cell subsets, and that human SLE B cells exhibit aberrant expression of X-linked genes and XIST RNA Interactome genes. Our data reveal that mislocalized XIST RNA, coupled with a dramatic reduction in heterochromatic modifications at the Xi in SLE, predispose for aberrant X-linked gene expression from the Xi, thus defining a novel genetic and epigenetic pathway that affects X-linked gene expression in human SLE B cells and likely contributes to the female-bias in SLE.

immunology↗