The establishment and maintenance of peripheral T cells is important to ensure appropriate immunity. In mammals, T cells are produced in the thymus before seeding the periphery early in life, and thereafter progressive thymus involution impairs new T cell production. Yet, peripheral T cells are maintained lifelong at approximately similar cell numbers.
View Article and Find Full Text PDFMaintenance of cell population size is fundamental to the proper functioning of multicellular organisms. Here, we describe a cell-intrinsic cell density-sensing pathway that enabled T cells to reach and maintain an appropriate population size. This pathway operated "kin-to-kin" or between identical or similar T cell populations occupying a niche within a tissue or organ, such as the lymph nodes, spleen, and blood.
View Article and Find Full Text PDFThe control of T cell survival is crucial for defense against infectious pathogens or emerging cancers. Although the survival of peripheral naïve T cells has been proposed to be controlled by interleukin-7 (IL-7) signaling and T cell receptor (TCR) activation by peptide-loaded major histocompatibility complexes (pMHC), the essential roles for these pathways in thymic output and T cell proliferation have complicated the analysis of their contributions to T cell survival. Here, we showed that the WD repeat–containing protein coronin 1, which is dispensable for thymic selection and output, promoted naïve T cell survival in the periphery in a manner that was independent of TCR and IL-7 signaling.
View Article and Find Full Text PDFThere are many different pathogenic stimuli that are able to activate the immune system, ranging from microbes that include bacteria, viruses, fungi, and parasites to host-derived triggers such as autoantigens that can induce autoimmunity as well as neoantigens involved in tumorigenesis. One of the key interactions shaping immunity toward these triggers involves the encounter of antigen-processing and -presenting cells such as macrophages and dendritic cells with T cells, resulting in immune responses that are highly selective for the antigenic trigger. Research over the past few years has implicated members of the coronin protein family, in particular coronin 1, in responses against several pathogenic triggers.
View Article and Find Full Text PDFFront Cell Infect Microbiol
April 2019
Microbes have interacted with eukaryotic cells for as long as they have been co-existing. While many of these interactions are beneficial for both the microbe as well as the eukaryotic cell, several microbes have evolved into pathogenic species. For some of these pathogens, host cell invasion results in irreparable damage and thus host cell destruction, whereas others use the host to avoid immune detection and elimination.
View Article and Find Full Text PDFFollowing thymic maturation, T cells egress as recent thymic emigrants to peripheral lymphoid organs where they undergo an additional maturation step to mature naive T cells that circulate through secondary lymphoid organs ready to be activated upon pathogenic challenges. Thymic maturation and peripheral T cell survival depend on several signaling cascades, but whether a dedicated mechanism exists that exclusively regulates homeostasis of mature naive T cells without affecting thymocytes and/or recent thymic emigrants remains unknown. In this article, we provide evidence for a specific and exclusive role of the WD repeat containing protein coronin 1 in the maintenance of naive T cells in peripheral lymphoid organs.
View Article and Find Full Text PDFSemin Immunopathol
November 2016
The decidua has been known as maternal uterine tissue, which plays essential roles in protecting the embryo from being attacked by maternal immune cells and provides nutritional support for the developing embryo prior to placenta formation. However, there are questions that still remain to be answered: (1) How does the decidua supply nutrition and provide a physical scaffold for the growing embryo, before placental vascular connection is established? (2) How is the balance between preventing an anti-embryo immune response and protecting both embryo and mother from infections established? To understand basic personas in decidual tissues, we review the structure of the decidua composed of terminally differentiated uterine stromal cells, blood vessels, and a number of repertoire of uterine local immune cells, including the well-known uterine natural killer (uNK) cells and recently discovered innate lymphoid cells (ILCs). Decidual macrophages and uterine dendritic cells (DCs) are supposed to modulate adaptive immunity via balancing cytokines and promoting generation of regulatory T (T) cells.
View Article and Find Full Text PDFBortezomib is one of the most widely used novel drugs for the treatment of multiple myeloma (MM). However, twice-weekly intravenous administration is associated with innegligible adverse events and treatment discontinuation. We therefore evaluated the long-term efficacy and feasibility of reduced frequency treatment with intravenous bortezomib in elderly patients with relapsed and/or refractory MM.
View Article and Find Full Text PDFThe junctional adhesion molecule (JAM)-B, a member of the immunoglobulin superfamily, is involved in stabilization of interendothelial cell-cell contacts, formation of vascular tubes, homeostasis of stem cell niches and promotion of leukocyte adhesion and transmigration. In the human placenta, JAM-B protein is abundant and mRNA transcripts are enriched in first-trimester extravillous trophoblast in comparison to the villous trophoblast. We here aimed to elucidate the yet unexplored spatio-temporal expression of JAM-B in the mouse placenta.
View Article and Find Full Text PDFCanola oil (Can) and hydrogenated soybean oil (H2-Soy) are commonly used edible oils. However, in contrast to soybean oil (Soy), they shorten the survival of stroke-prone spontaneously hypertensive (SHRSP) rats. It has been proposed that the adverse effects of these oils on the kidney and testis are caused at least in part by dihydro-vitamin K (VK) 1 in H2-Soy and unidentified component(s) in Can.
View Article and Find Full Text PDFBackground: Hepatocellular carcinoma (HCC), the fifth most common cancer type and the third highest cause of cancer death worldwide, develops in different types of liver injuries, and is mostly associated with cirrhosis. However, non-alcoholic fatty liver disease often causes HCC with less fibrosis, and the number of patients with this disease is rapidly increasing. The high mortality rate and the pathological complexity of liver diseases and HCC require blood biomarkers that accurately reflect the state of liver damage and presence of HCC.
View Article and Find Full Text PDFHepatocellular carcinoma (HCC) is a widespread fatal disease and the third most common cause of cancer deaths. Here, we show the potent anti-HCC effect of the circulating protein AIM. As in adipocytes, AIM is incorporated into normal hepatocytes, where it interferes with lipid storage.
View Article and Find Full Text PDFWe investigated whether body temperature (BT) regulatory mechanisms are influenced by dietary fatty acids (FA). Male Wistar rats were fed a high-fat diet containing fish oil (HFD), soybean oil (HSD) or lard (HLD). At the 20-week intervention, the BT of the HSD and HLD groups were lower than that of the normal diet (ND) group in the light and dark periods.
View Article and Find Full Text PDFThe objective of this study was to identify the clinical features associated with neurological deterioration within 30 days of ischemic stroke patients with spontaneous cevicocranial dissection (SCCD) and clarify the effect on outcomes. We retrospectively identified 18 patients with SCCD (1.6%, 3 women, 52 ± 16 years old) among 1,112 patients with acute ischemic stroke within 7 days after onset.
View Article and Find Full Text PDFBackground: Assessment of sentinel lymph node status is commonly performed in the treatment of cutaneous melanoma. However, there are no definite guidelines for thin melanomas with Breslow tumor thickness <1.0 mm, in part because thin melanomas are relatively infrequently positive for lymph node metastasis.
View Article and Find Full Text PDFEpidemiologic and ecologic studies suggest that dietary fat plays an important role in the development of obesity. Certain Wistar rat strains do not become obese when fed high-fat diets unlike others. In a preliminary study, we confirmed that Slc:Wistar/ST rats did not become obese when fed high-fat diets.
View Article and Find Full Text PDFNatural immunoglobulin M (IgM) is reactive to autoantigens and is believed to be important for autoimmunity. Blood pentameric IgM loaded with antigens forms a large immune complex (IC) that contains various elements, including apoptosis inhibitor of macrophage (AIM). Here we demonstrate that this IgM-AIM association contributes to autoantibody production under obese conditions.
View Article and Find Full Text PDFThe mouse macrophage-derived apoptosis inhibitor of macrophage (AIM), which is incorporated into adipocytes and induces lipolysis by suppressing fatty acid synthase (FAS) activity, possesses three potential N-glycosylation sites. Inactivation of N-glycosylation sites revealed that mouse AIM contains two N-glycans in the first and second scavenger receptor cysteine-rich domains, and that depletion of N-glycans decreased AIM secretion from producing cells. Interestingly, the lack of N-glycans increased AIM lipolytic activity through enhancing AIM incorporation into adipocytes.
View Article and Find Full Text PDFBackground: The initial 24 h after thrombolysis are critical for patients' conditions, and continuous neurological assessment and blood pressure measurement are required during this time. The goal of this study was to identify the clinical factors associated with early neurological deterioration (END) within 24 h of stroke patients receiving intravenous recombinant tissue plasminogen activator (rt-PA) therapy and to clarify the effect of END on 3-month outcomes.
Methods: A retrospective, multicenter, observational study was conducted in 10 stroke centers in Japan.
Under fasting conditions, triacylglycerol in adipose tissue undergoes lipolysis to supply fatty acids as energy substrates. Such lipolysis is regulated by hormones, which activate lipases via stimulation of specific signalling cascades. We previously showed that macrophage-derived soluble protein, AIM induces obesity-associated lipolysis, triggering chronic inflammation in fat tissue which causes insulin resistance.
View Article and Find Full Text PDFBackground: Failure to detect the sphenoidal segment of the middle cerebral artery (M1) on transcranial color-coded sonography (TCCS) results from either M1 occlusion or an insufficient temporal bone window (TBW). We sought to identify a simple indicator on B mode images for M1 evaluation.
Methods: Consecutive acute ischemic stroke patients with an intact M1 segment underwent prospective TCCS evaluation.
Background: To examine the therapeutic effect of intravenous recombinant tissue plasminogen activator (rt-PA) therapy for stroke patients receiving maintenance hemodialysis (HD). methods: Of 600 stroke patients receiving intravenous rt-PA using 0.6 mg/kg alteplase who were enrolled in a multicenter observational study in Japan, 4 patients (3 men, 64-77 years old) on maintenance HD were studied.
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