bioRxiv Science⌕ Search

Biology subjects

Herrero-Fernandez, B.

Publications and source records attributed to Herrero-Fernandez, B..

3 recordsLinked to original sources

Lamin A/C regulates the compartment-specific contributions of immune and stromal cells to intestinal inflammation and colitis-associated colon cancer

Inflammatory bowel disease (IBD) arises from dysregulated crosstalk between innate immune, adaptive immune, and stromal compartments, yet the compartment-specific mechanisms driving tissue injury and tumorigenesis remain incompletely defined. To address this gap, we used conditional knockout and overexpression mouse models together with human IBD biopsy analysis to dissect the compartment-specific roles of lamin A/C in intestinal inflammation and colitis-associated tumorigenesis. Pan-hematopoietic lamin A/C deletion attenuated acute dextran sulfate sodium (DSS)-induced colitis. Myeloid-specific lamin A/C deletion ameliorated chronic colitis and was associated with altered dendritic cell (DC) programs, enhanced regulatory T cell (Treg) responses, and reduced effector T cell activation. Adoptive transfer of lamin A/C-deficient bone marrow-derived DCs recapitulated this reduced-damage phenotype in DSS colitis, while proteomic profiling revealed reduced antigen-processing and inflammatory programs together with enhanced metabolic and mucosal defense pathways. T cell-specific lamin A/C deletion reduced the Th1/Treg ratio and limited tumor development by suppressing chronic inflammation, whereas T cell-specific lamin A/C overexpression promoted severe Th1-skewed pathology, sustained intestinal inflammation, and increased colitis-associated tumor burden. Stromal fibroblast-specific lamin A/C deletion generated a tissue-protective niche characterized by enhanced epithelial barrier gene expression, regulatory cytokine production, and remodeling of the local immune milieu. Human IBD biopsies revealed compartment-specific lamin A/C alterations consistent with the murine findings. In lamina propria CD3 T cells, lamin A/C levels were blunted in IBD and associated with local histological severity rather than IBD diagnosis, whereas epithelial lamin A/C showed a steeper crypt-axis spatial gradient in a Crohns disease-specific pattern. Together, these findings identify lamin A/C as a cell-type- and context-dependent regulator of intestinal inflammation and tumorigenesis.

immunology↗

Regulation of B cell tolerance and autoimmunity by miR-130b

Breakdown of B cell tolerance is a central feature of autoimmune diseases, yet the molecular mechanisms underlying the female predominance of these diseases remain unclear. Here, we identified miR-130b as an essential component of a miRNA network, defined by the GUGCA seed motif, that regulates central B cell tolerance. Elevated miR-130b levels impaired tolerance by promoting the survival of immature B cells upon B cell antigen receptor engagement. This network converged on the estrogen receptor pathway through downregulation of Esr1 and Pten. Genetic ablation of Esr1 in immature B cells was sufficient to compromise central B cell tolerance in females, but not in males, revealing an unrecognized role for ER in this process. In males, Esr1 deficiency reduced bone marrow B cell numbers, whereas in females, B cell numbers were preserved, with a greater proportion of cells displaying lower surface CD19 levels. Transcriptomic analysis revealed sex-specific genetic programs characterized by defective B cell development and skewed immunoglobulin gene usage in males, and increased PI3K-AKT signaling in females. In females, this molecular rewiring compensated for developmental defects, but also attenuated central tolerance mechanisms, allowing the escape of autoreactive B cells to the periphery. In patients with multiple sclerosis, elevated levels of miR-130b in circulating vesicles correlated with more severe disease, including increased formation of new demyelinating lesions, cognitive decline, and neurodegeneration. Together, our findings identify a sex-specific ER-dependent checkpoint in B cell tolerance controlled by a seed-driven miRNA network, providing a mechanistic framework for female predisposition to autoimmunity.

immunology↗

Role of Lamin A/C on dendritic cell function in antiviral immunity

Dendritic cells (DCs) play a crucial role in orchestrating immune responses, particularly in promoting IFN{gamma}-producing-CD8 cytotoxic T lymphocytes (CTLs) and IFN{gamma}-producing -CD4 T helper 1 (Th1) cells, which are essential for defending against viral infections. Additionally, the nuclear envelope protein lamin A/C has been implicated in T cell immunity. Nevertheless, the intricate interplay between innate and adaptive immunity in response to viral infections, particularly the role of lamin A/C in DC functions within this context, remains poorly understood. In this study, we demonstrate that mice lacking lamin A/C in myeloid LysM promoter-expressing cells exhibit a reduced capacity to induce Th1 and CD8 CTL responses, leading to impaired clearance of acute primary Vaccinia virus (VACV) infection. Remarkably, in vitro-generated granulocyte macrophage colony-stimulating factor bone marrow-derived DCs (GM-CSF BMDCs) show high levels of lamin A/C. Lamin A/C absence on GM-CSF BMDCs does not affect the expression of costimulatory molecules on the cell membrane but it reduces the cellular ability to form immunological synapses with naive CD4 T cells. Lamin A/C deletion induces alterations in NF{kappa}B nuclear localization, thereby influencing NF{kappa}B-dependent transcription. Furthermore, lamin A/C ablation modifies the epigenetic signature of BMDCs, predisposing these cells to mount a less effective antiviral response upon TLR stimulation. This study highlights the critical role of DCs in interacting with CD4 T cells during antiviral responses and elucidates the molecular mechanisms through which lamin A/C modulates DC function via epigenetic and transcriptional regulation.

immunology↗