Environmental nano- and microplastics (NMPs) pose serious environmental issues, yet there is no established technique to assess their impact on health through oral ingestion. Here, we present a protocol to assess the impact of NMPs in the intestinal immune microenvironments by employing chronic exposure to NMPs in a mouse model. We describe steps for administration of NMPs, feces and tissue collection, and colonic gut digestion.
View Article and Find Full Text PDFThe genome organizer, special AT-rich binding protein-1 (SATB1), functions to globally regulate gene networks during primary T cell development and plays a pivotal role in lineage specification in CD4 helper-, CD8 cytotoxic-, and FOXP3 regulatory-T cell subsets. However, it remains unclear how gene expression is controlled, particularly in effector T cell function. Here, by using a novel reporter mouse strain expressing SATB1-Venus and genome editing, we have identified a -regulatory enhancer, essential for maintaining expression specifically in T2 cells.
View Article and Find Full Text PDFEnvironmental microplastics have emerged as a critical issue in maintaining the planetary ecosystem. In this study, we generated particulate microplastics from polyethylene terephthalate (PM-PET) and investigated their impact in the gut by using mouse models and implementing histological examinations, as well as multi-omics analysis for colonic immune cells and microbiota. As a result, histological approaches showed that chronic and physiological low dose exposure of PM-PET did not affect intestinal pathology and mucin barriers, respectively.
View Article and Find Full Text PDFThe significant increase in food allergy incidence is correlated with dietary changes in modernized countries. Here, we investigated the impact of dietary emulsifiers on food allergy by employing an experimental murine model. Mice were exposed to drinking water containing 1.
View Article and Find Full Text PDFThe Runt-related transcription factor (RUNX) family of proteins are crucial for many developmental and immuno-physiological processes. Their importance in cellular and tissue development has been repeatedly demonstrated as they are often found mutated and implicated in tumorigenesis. Most importantly, RUNX have now emerged as critical regulators of lymphocyte function against pathogenic infections and tumorigenic cells, the latter has now revolutionized our current understandings as to how RUNX proteins contribute to control tumor pathogenicity.
View Article and Find Full Text PDFChronic infection with persistent antigenic stimulation results in the generation of exhausted CD8 T cells, which are considered defective effector CD8 T cells, and thus compromises effective immune responses. However, recent studies have illustrated that exhausted CD8 T cells may be purposely generated and maintained to provide mild immune responses against chronic infection or cancer, which can be safer over a long period of time than strong immune responses. Indeed, a specific population of exhausted CD8 T cells that behaves similarly to self-renewing stem cells and provides a continuous supply of exhausted CD8 T cells has been identified, indicating that this population can be considered progenitors of exhausted CD8 T cells.
View Article and Find Full Text PDFCCL5 is a unique chemokine with distinct stage and cell-type specificities for regulating inflammation, but how these specificities are achieved and how CCL5 modulates immune responses is not well understood. Here we identify two stage-specific enhancers: the proximal enhancer mediates the constitutive CCL5 expression during the steady state, while the distal enhancer located 1.35 Mb from the promoter induces CCL5 expression in activated cells.
View Article and Find Full Text PDFTemporal down-regulation of the CD8 co-receptor after receiving positive-selection signals has been proposed to serve as an important determinant to segregate helper versus cytotoxic lineages by generating differences in the duration of TCR signaling between MHC-I and MHC-II selected thymocytes. By contrast, little is known about whether CD8 also modulates TCR signaling engaged by the non-classical MHC-I-like molecule, CD1d, during development of invariant natural killer T (iNKT) cells. Here, we show that constitutive transgenic CD8 expression resulted in enhanced differentiation of innate memory-like CD8 thymocytes in both a cell-intrinsic and cell-extrinsic manner, the latter being accomplished by an increase in the IL-4-producing iNKT2 subset.
View Article and Find Full Text PDFThe Runt-related transcription factors (RUNX) transcription factors have been known for their critical roles in numerous developmental processes and diseases such as autoimmune disorders and cancer. Especially, RUNX proteins are best known for their roles in hematopoiesis, particularly during the development of T cells. As scientists discover more types of new immune cells, the functional diversity of RUNX proteins also has been increased over time.
View Article and Find Full Text PDFTle/Groucho proteins are transcriptional corepressors interacting with Tcf/Lef and Runx transcription factors, but their physiological roles in T cell development remain unknown. Conditional targeting of Tle1, Tle3 and Tle4 revealed gene dose-dependent requirements for Tle proteins in CD8 lineage cells. Upon ablating all three Tle proteins, generation of CD8 T cells was greatly diminished, largely owing to redirection of MHC-I-selected thymocytes to CD4 lineage; the remaining CD8-positive T cells showed aberrant up-regulation of CD4 lineage-associated genes including , , , and Mechanistically, Tle3 bound to Runx-occupied silencer, in post-selection double-positive thymocytes to prevent excessive ThPOK induction and in mature CD8 T cells to silence expression.
View Article and Find Full Text PDFThe moment magnitude () 5.4 Pohang earthquake, the most damaging event in South Korea since instrumental seismic observation began in 1905, occurred beneath the Pohang geothermal power plant in 2017. Geological and geophysical data suggest that the Pohang earthquake was induced by fluid from an enhanced geothermal system (EGS) site, which was injected directly into a near-critically stressed subsurface fault zone.
View Article and Find Full Text PDFT-lineage committed precursor thymocytes are screened by a fate-determination process mediated via T cell receptor (TCR) signals for differentiation into distinct lineages. However, it remains unclear whether any antecedent event is required to couple TCR signals with the transcriptional program governing lineage decisions. Here we show that Bcl11b, known as a T-lineage commitment factor, is essential for proper expression of ThPOK and Runx3, central regulators for the CD4-helper/CD8-cytotoxic lineage choice.
View Article and Find Full Text PDFSince the first draft of the human genome sequence was released in 2001, unprecedentedly rapid progress has been made in whole genome-wide approaches by utilizing next-generation-sequencing technologies. The last decade alone has generated enormous data in the forms of exome sequencing, transcriptomes, transcription factor occupancy, genomic variation profiling and epigenetic modifications. One of the most striking realizations from sequencing studies has been the discovery and characterization of non-coding RNAs (ncRNAs).
View Article and Find Full Text PDFDuring hematopoiesis, a variety of cells are generated from stem cells through successive rounds of cell fate determination processes. Studies in the last two decades have demonstrated the involvement of Runx transcription factor family members in differentiation of multiple types of hematopoietic cells. Along with evolutionary conservation, the Runx family is considered to be one of the ancestral regulators of hematopoiesis.
View Article and Find Full Text PDFA TCRβ enhancer, known as the Eβ enhancer, plays a critical role in V(D)J recombination and transcription of the Tcrb gene. However, the coordinated action of trans-acting factors in the activation of Eβ during T cell development remains uncharacterized. Here, we characterized the roles of Runx complexes in the regulation of the Eβ function.
View Article and Find Full Text PDFT-cell development occurs in multipotent progenitors arriving in the thymus, which provides a highly specialized microenvironment. Specification and sequential commitment processes to T cells begin in early thymic progenitors upon receiving thymus-specific environmental cues, resulting in the activation of the genetically programmed transcriptional cascade that includes turning on and off numerous transcription factors in a precise manner. Thus, early thymocyte differentiation has been an excellent model system to study cell differentiation processes.
View Article and Find Full Text PDFThe fetal liver is a major hematopoietic site containing progenitor cells that give rise to nearly all blood cells, including B-1 cells. Because the fetal liver is not a de novo site of hematopoietic stem cell (HSC) or progenitor-cell emergence, it must be seeded by yolk sac (YS)-derived erythromyeloid progenitors at embryonic day (E) 8.5-E10 and aorta-gonado-mesonephros (AGM)-derived HSCs at E10.
View Article and Find Full Text PDFCD4(+) helper and CD8(+) cytotoxic T cells differentiate from common precursors in the thymus after T-cell receptor (TCR)-mediated selection. Commitment to the helper lineage depends on persistent TCR signals and expression of the ThPOK transcription factor, whereas a ThPOK cis-regulatory element, ThPOK silencer, represses Thpok gene expression during commitment to the cytotoxic lineage. Here, we show that silencer-mediated alterations of chromatin structures in cytotoxic-lineage thymocytes establish a repressive state that is epigenetically inherited in peripheral CD8(+) T cells even after removal of the silencer.
View Article and Find Full Text PDFAlthough Runx and Cbfβ transcription factor complexes are involved in the development of multiple hematopoietic lineages, their precise roles in early mouse B lymphocyte differentiation remain elusive. In this study, we examined mouse strains in which Runx1, Runx3, or Cbfβ were deleted in early B lineage progenitors by an mb1-cre transgene. Loss of Runx1, but not Runx3, caused a developmental block during early B lymphopoiesis, resulting in the lack of IgM(+) B cells and reduced V(H) to DJ(H) recombination.
View Article and Find Full Text PDFRunx transcription factor family proteins have essential roles during T-cell development by either activating or repressing target genes. For instance, lineage- and stage-specific expression of Cd4 and ThPOK is controlled by a transcriptional silencer embedded in each locus, whose activity requires bindings of Runx complexes. The evolutionarily conserved VWRPY penta-peptide sequences in Runx proteins have been shown to be responsible for repressive function as a platform to recruit Groucho/TLE transcriptional corepressors.
View Article and Find Full Text PDFThe sialomucin CD43 is highly expressed on most hematopoietic cells. In this study, we show that the CD43 ectodomain is shed from murine granulocytes, mast cells, and T cells, but not from macrophages. To study the significance of CD43 shedding, we constructed 2 CD43/34 chimeras in which the CD43 membrane-proximal or transmembrane domain was swapped with the corresponding domain from CD34 that is not shed from cells.
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