Biology subjects

Vazquez, E.

Publications and source records attributed to Vazquez, E..

5 recordsLinked to original sources

bioRxiv2024

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↗

bioRxiv2024

Evolutionary convergence of sensory circuits in the pallium of amniotes

The amniote pallium contains sensory circuits structurally and functionally equivalent, yet their evolutionary relationship remains unresolved. Our study employs birthdating analysis, single-cell RNA and spatial transcriptomics, and mathematical modeling to compare the development and evolution of known pallial circuits across birds (chick), lizards (gecko) and mammals (mouse). We reveal that neurons within these circuits stations are generated at varying developmental times and brain regions across species, and found an early developmental divergence in the transcriptomic progression of glutamatergic neurons. Together, we show divergent developmental and evolutionary trajectories in the pallial cell types of sauropsids and mammals. Our research highlights significant differences in circuit construction rules among species and pallial regions. Interestingly, despite these developmental distinctions, the sensory circuits in birds and mammals appear functionally similar, which suggest the convergence of high-order sensory processing across amniote lineages.

developmental biology↗

bioRxiv2023

BirthSeq, a new method to isolate and analyze dated cells from any tissue in vertebrates

Embryonic development is a complex and dynamic process that unfolds over time and involves the production of increasing numbers of cells, as well as the diversification of different cell types. The impact of developmental time on the formation of the central nervous system is well-documented, with evidence showing that time plays a critical role in establishing the identity of neuronal subtypes. However, the study of how time translates into genetic instructions driving cell fate is limited by the scarcity of suitable experimental tools. We introduce BirthSeq, a new method for isolating and analyzing cells based on their birth date. This innovative technique allows for in vivo labeling of cells, isolation via FACS, and analysis using high-throughput techniques. We demonstrate the effectiveness of BirthSeq for single-cell RNA sequencing and novel spatially resolved transcriptomic approaches in brain development across three vertebrate species (mouse, chick, and gecko). Overall, BirthSeq provides a versatile tool for studying any tissue in any vertebrate organism, helping to fill the necessity in developmental biology research by targeting cells and their temporal cues. SUMMARY STATEMENTBirthSeq allows the isolation and investigation of alive cells according to their birthdate, in any kind of tissue and vertebrate species.

developmental biology↗

bioRxiv2023

NGFR regulates germinal center B-cell activation and negative selection

The expression of the Nerve growth factor receptor (NGFR) has been described in follicular dendritic cells (FDCs), the major lymphoid stromal cell (LSC) compartment regulating B-cell activation within germinal centers (GCs). However, the role of NGFR in humoral response is not well defined. In this work, we have studied the effect of Ngfr KO in LNs organization and function. Ngfr KO led to spontaneous GC formation and expansion of GC B-cell compartment which were related to Ngfr depletion in non-hematopoietic radioresistant compartment. In agreement, Ngfr KO mice showed alterations in LSC with an increased frequency of FDCs harboring an activated phenotype characterized by the overexpression of CD21/35, MAdCAM-1, and VCAM-1. Moreover, Ngfr KO mice showed GC ectopic location, loss of polarization, impaired high-affinity antibody production, and increased circulating autoantibodies. In addition, Ngfr KO/Bcl2 Tg mice displayed increased levels of autoantibodies, higher incidence of autoimmunity, and decreased overall survival. Our work shows that NGFR maintains GC structure and functionality, being involved in the regulation of antibody production and immune tolerance.

immunology↗

bioRxiv2021

Expression of the cancer-associated DNA polymerase ϵ P286R in fission yeast leads to translesion synthesis polymerase dependent hypermutation and defective DNA replication

Somatic mutations in the proofreading domain of the replicative DNA polymerase {varepsilon} (POLE-exonuclease domain mutations, POLE-EDMs) are frequently found in colorectal and endometrial cancers and, occasionally, in other tumours. POLE-associated cancers typically display hypermutation, microsatellite stability and a unique mutational signature, with a predominance of C > A transversions in the context TCT. To understand better the contribution of hypermutagenesis to tumour development, we have modelled the most recurrent POLE-EDM (POLE-P286R) in Schizosaccharomyces pombe. Whole-genome sequencing analysis revealed that the corresponding pol2-P287R allele also has a strong mutator effect in vivo, with a high frequency of base substitutions and relatively few frameshift mutations. The mutations are equally distributed across different genomic regions, but they occur within an AT-rich context. The most abundant base-pair changes are TCT > TAT transversions and, in contrast to human mutations, TCG > TTG transitions are not elevated, likely due to the absence of cytosine methylation in fission yeast. The pol2-P287R variant has an increased sensitivity to elevated dNTP levels and DNA damaging agents, and shows reduced viability on depletion of the Pfh1 helicase. In addition, S phase is aberrant and RPA foci are elevated, suggestive of persistent ssDNA or DNA damage, and the pol2-P287R mutation is synthetically lethal with rad3 inactivation, indicative of checkpoint activation. Significantly, deletion of genes encoding some translesion synthesis polymerases, most notably Pol {kappa}, partially suppresses pol2-P287R hypermutation, indicating that polymerase switching contributes to this phenotype. AUTHOR SUMMARYCancer is a genetic disease caused by mutations that lead to uncontrolled cell proliferation and other tumour properties. Defects in DNA repair or replication can lead to cancer development by increasing the likelihood that cancer-causing mutations will happen. Here we look at a pathogenic variant of a polymerase involved in genome replication (DNA polymerase POLE-P286R). This variant is associated with highly mutated cancer genomes. By introducing this mutation into the polymerase gene of a model organism, fission yeast, we show that it causes a large increase in single base substitutions, scattered throughout the genome. The sequence context of mutations is similar in fission yeast and humans, suggesting that the yeast model is useful for understanding how POLE-P286R causes such a high mutation rate. Yeast POLE-P286R cells show slow chromosome replication, suggesting that the polymerase has difficulty in copying certain chromosomal regions. Yeast POLE-P286R cells become inviable when the concentration of dNTP building blocks for DNA synthesis is increased, probably because the mutation rate is pushed to an intolerable level. Interestingly, we find that specialised polymerases that are tolerant of DNA damage contribute to the high mutation rate caused by POLE-P286R. These findings have implications for the therapy of POLE-P286R tumours.

cancer biology↗