Search bioRxiv⌕ Search

Biology subjects

Kageyama, T.

Publications and source records attributed to Kageyama, T..

9 recordsLinked to original sources

Epigenomic and transcriptomic germ-free ageing atlas reveals sterile inflammation as an intrinsic ageing feature

Inflammageing is a hallmark of ageing. Commensal microbiota plays crucial roles in maintaining tissue homeostasis, yet its impact on cellular ageing and inflammageing remains poorly understood. Here we present a comprehensive single-cell epigenomic and transcriptomic atlas of tissues from mice aged under specific pathogen-free (SPF) or germ-free (GF) conditions. Microbiota conferred beneficial effects in young mice but accelerated various ageing features in old, such as age-related AP-1 pathway upregulation, senescence and transcriptomic alterations, likely due to age-associated dysbiosis. Strikingly, inflammatory signatures persisted across cell types in aged GF mouse tissues, establishing sterile inflammation as an intrinsic feature of ageing. Age-associated B cells expanded equally under GF and SPF conditions, raising the possibility that they function as intrinsic, microbiota-independent drivers of inflammageing and potential therapeutic targets. The atlas provides a resource for distinguishing intrinsic ageing features from those modulated by the microbiota, illuminating mechanisms of cellular ageing and potential anti-ageing interventions. HighlightsSterile inflammation and age-associated B cell expansion are prominent intrinsic ageing features The upregulation of age-associated AP-1 pathways and senescence of alveolar macrophages are attenuated in germ-free condition Germ-free condition induces premature ageing-like features in young mouse tissues but delays ageing features in old mice across multiple cell types

genomics↗

Sox4 in Treg Cells Suppresses IL-10 Production via c-Maf Degradation and Exacerbates Type 2 Inflammation

The anti-inflammatory cytokine interleukin-10 (IL-10) produced by regulatory T (Treg) cells plays a crucial role in regulating allergic airway inflammation. However, the mechanisms governing IL-10 production in Treg cells remain unclear. In this study, we first identified Sox4 as a gene whose expression is down-regulated in IL-10-producing Treg cells. Comprehensive gene expression profiling of Sox4-deficient Treg cells and Sox4-overexpressing Treg cells revealed specific downregulation of Il10 and Ctla4 by Sox4. Sox4-deficient Treg cells exhibited increased IL-10 production and CTLA-4 expression both in vitro and in vivo and strongly suppressed Th2 cell proliferation compared with Sox4-expressing Treg cells. In a house dust mite (HDM)-induced asthma model, Treg-specific Sox4-deficient (Sox4-cKO) mice exhibited IL-10-dependent reductions in eosinophilic inflammation and Th2 cell infiltration in the airways. A comparison of Sox4-cKO and wild-type Treg cells in the same inflamed environment in mixed bone marrow chimeric mice with HDM-induced asthma revealed that Sox4-mediated suppression of c-Maf is cell-intrinsic. In addition, overexpression of Sox4 in Treg cells repressed the activation of c-Maf-regulated chromatin regions, including those around the Il10 and Ctla4 loci. Moreover, Sox4-induced suppression of IL-10 and CTLA-4 in Treg cells was rescued by forced expression of c-Maf. While Sox4 did not significantly affect Maf mRNA levels, Sox4 degraded c-Maf proteins in Treg cells through its 33 C-terminal residues. Via a domain distinct from its C-terminus, Sox4 physically interacted with c-Maf, subsequently facilitating its degradation through a ubiquitin-proteasome pathway. These findings elucidate a mechanism by which Sox4 influences the asthmatic responses by regulating the c-Maf/IL-10 axis in lung Treg cells.

immunology↗

Hair Dermal papilla maintain its hair inducing characteristics via autocrine exosomal miR-23a-3p

Human dermal papilla cells (hDPCs) are specialized mesenchymal cells that regulate hair follicle development and drive the hair cycle. However, when cultured in vitro, hDPCs progressively lose their hair-inductive capacity. This decline may be closely associated with the absence of the native microenvironmental niche, which plays a critical role in maintaining hDPC identity and function in vivo. In addition to extrinsic cues, autocrine signaling within the dermal papilla itself may serve as a key mechanism for sustaining its regenerative potential. In this study, we present a novel growth model that enables real-time tracking of hDPC functional recovery, with particular attention to autocrine signaling and niche reprogramming. Our results reveal that intrinsic feedback loops are essential for maintaining hDPC function during the anagen phase. By elucidating the dynamic interplay between hDPC expansion and hair-inductive capacity, this work advances our understanding of hair follicle biology and highlights new avenues for developing regenerative therapies for hair loss.

bioengineering↗

Direct genome sequencing of respiratory viruses from low viral load clinical specimens using target capture sequencing technology

The use of metagenomic next-generation sequencing technology to obtain complete viral genome sequences directly from clinical samples with low viral load remains challenging--especially in the case of respiratory viruses--due to the low copy number of viral versus host genomes. To overcome this limitation, target capture sequencing for the enrichment of specific genomes has been developed and applied for direct genome sequencing of viruses. However, as the efficiency of enrichment varies depending on the probes, the type of clinical sample, etc., validation is essential before target capture sequencing can be applied to clinical diagnostics. Here we evaluated the utility of target capture sequencing with a comprehensive viral probe panel for clinical respiratory specimens collected from patients diagnosed with SARS-CoV-2 or influenza type A. We focused on clinical specimens containing low copy numbers of viral genomes. Target capture sequencing yielded approximately 180- and 2000-fold higher read counts of SARS-CoV-2 and influenza A virus, respectively, than metagenomic sequencing when the RNA extracted from specimens contained 59.3 copies/{micro}L of SARS-CoV-2 or 544 copies/{micro}L of influenza A virus, respectively. In addition, the target capture sequencing identified sequence reads in all SARS-CoV-2- or influenza type A-positive specimens with <26 RNA copies/{micro}L, some of which also yielded >70% of the full-length genomes of SARS-CoV-2 or influenza A virus. Furthermore, the target capture sequencing using comprehensive probes identified co-infections with viruses other than SARS-CoV-2, suggesting that this approach will not only detect a wide range of viruses, but also contribute to epidemiological studies.

genomics↗

Commensal-specific CD4 T cells promote inflammation in the central nervous system via molecular mimicry

Commensal bacteria are critical regulators of both tissue homeostasis and the development and exacerbation of autoimmunity. However, it remains unclear how the intestinal microbiota contributes to inflammation in tissues such as the central nervous system (CNS) where these microbes are typically absent and whether T cell receptor (TCR) specificity for commensal-derived antigens is important to the development of tissue inflammation-related outcomes. Here, we found that ileum- and cecum-colonizing segmented filamentous bacteria (SFB)-specific T cells (clone TCR7B8) can infiltrate the CNS wherein they can be reactivated and produce high levels of inflammatory cytokines including IFN{gamma}, IL-17A, TNF, and GM-CSF in the absence of regulatory T cells. In contrast, other SFB-specific T cells (clone TCR1A2) recognizing an epitope in which 8/9 amino acids overlap with those recognized by TCR7B8 failed to induce such neuroinflammation. Despite their similar SFB-derived peptide antigen targets, TCR7B8 was found to recognize peptides derived from host proteins including receptor tyrosine-protein kinase ErbB2, trophinin 1, and anaphase-promoting complex subunit 2 in vitro, whereas TCR1A2 did not, indicating that TCR7B8 induces CNS inflammation via molecular mimicry. Immune checkpoint blockade accelerated TCR7B8-mediated CNS inflammation, suggesting a potential cause of immune-related adverse events induced in cancer patients undergoing such treatment. Together, our findings reveal a potential mechanism whereby gut commensal-specific T cells are dysregulated and contribute to extraintestinal inflammation.

immunology↗

Reprogramming of three-dimensional microenvironments for in vitro hair follicle induction

During embryonic development, reciprocal interactions between epidermal and mesenchymal layers trigger hair follicle morphogenesis. This study revealed that microenvironmental reprogramming via control over these interactions enabled hair follicle induction in vitro. A key approach is to modulate spatial distributions of epithelial and mesenchymal cells in their spontaneous organization. The de novo hair follicles with typical morphological features emerged in aggregates of the two cell types, termed hair follicloids, and hair shafts sprouted with near 100% efficiency in vitro. The hair shaft length reached [~]3 mm in culture. Typical trichogenic signaling pathways were upregulated in hair follicloids. Owing to replication of hair follicle morphogenesis in vitro, production and transportation of melanosomes were also monitored in the hair bulb region. This in vitro hair follicle model might be valuable for better understanding hair follicle induction, for evaluating hair growth as well as the inhibition of hair growth by drugs, and modeling gray hairs in a well-defined environment. TeaserIn tissue morphogenesis, different types of cells harmonize in a pre-programmed manner using messenger systems such as epithelial-mesenchymal interactions. Organoids are a promising tool to elucidate such mechanisms on a molecular level. This work describes a strategy for reprograming three-dimensional microenvironments to trigger the initiation of in vitro regeneration of hair follicle organoids. Hair follicle organoids generated fully matured hair follicles, enabling the monitoring of hair follicle morphogenesis in vitro and determination of signaling pathways involved in early hair follicle morphogenesis. The principles uncovered herein may be relevant to other organ systems and will contribute to our understanding of developmental phenomena in physiological and pathological processes, eventually opening up new research avenues for the development of new treatment strategies.

bioengineering↗

Effects of source sample amount on biodiversity surveys of bacteria, fungi, and nematodes in soil ecosystems

Bacteria, fungi, and nematodes are major components of soil ecosystems, playing pivotal roles in belowground material cycles and biological community processes. A number of studies have recently uncovered the diversity and community structure of those organisms in various types of soil ecosystems based on DNA metabarcoding (amplicon sequencing). However, because each of the most previous studies examined only one or two of the three organismal groups, it remains an important challenge to reveal the entire picture of soil community structure. We herein examined how we could standardize DNA extraction protocols for simultaneous DNA metabarcoding of bacteria, fungi, and nematodes. Specifically, in an Illumina sequencing analysis of forest and farmland soil samples, we performed DNA extraction at five levels of soil-amount settings (0.5 g, 2 g, 5 g, 10 g, and 20 g). We then found that DNA extraction with the 0.5-g soil setting, which had been applied as default in many commercial DNA extraction kits, could lead to underestimation of -diversity in nematode community. The detected family-level diversity of nematodes, in particular, increased with increasing soil amounts in DNA extraction. Our analyses also indicated that dissimilarity ({beta}-diversity) of community structure among replicate samples were higher in fungi and nematodes than in bacteria, suggesting difference in basic levels of spatial heterogeneity among the three organismal groups. These findings provide platforms for optimizing DNA metabarcoding protocols commonly applicable to major groups of organisms in soil ecosystems.

ecology↗

Immunological features that determine the strength of antibody responses to BNT162b2 mRNA vaccine against SARS-CoV-2

We analyzed peripheral blood mononuclear cells (PBMCs) of each 20 individuals with a high anti-SARS-CoV-2 antibody titer and a low antibody titer out of 1,774 healthcare workers who received BNT162b2 mRNA vaccine. A higher antibody titer was associated with the frequencies of naive and transitional B cells before vaccination. In addition, fold changes in the frequency of activated CD8+ T cells upon vaccination were correlated with the antibody titers.

immunology↗

Redundant cytokine requirement for intestinal microbiota-induced Th17 cell differentiation in draining lymph nodes

Differentiation of intestinal T helper 17 (Th17) cells, which contribute to mucosal barrier protection from invasive pathogens, is dependent on colonization with distinct commensal bacteria. Segmented filamentous bacteria (SFB) are sufficient to support Th17 cell differentiation in mouse, but the molecular and cellular requirements for this process remain incompletely characterized. Here we show that intestine-draining mesenteric lymph nodes (MLN) are the dominant site of SFB-induced intestinal Th17 cell differentiation. Subsequent migration of these cells to the intestinal lamina propria is dependent on their up-regulation of integrin {beta}7. Stat3-dependent induction of ROR{gamma}t, the Th17 cell-specifying transcription factor, largely depends on IL-6, but signaling through the receptors for IL-21 and IL-23 can compensate for absence of IL-6 to promote SFB-directed Th17 cell differentiation. These results indicate that redundant cytokine signals guide commensal microbe-dependent Th17 cell differentiation in the MLN and accumulation of the cells in the lamina propria.

immunology↗