Akio Takezaki, Shin-ichi Tsukumo, Yasuhiro Setoguchi, G Julie Ledford, Hisatsugu Goto, Kazuyoshi Hosomichi, Hisanori Uehara, Yasuhiko Nishioka and Koji Yasutomo : A homozygous SFTPA1 mutation drives necroptosis of type II alveolar epithelial cells in patients with idiopathic pulmonary fibrosis., The Journal of Experimental Medicine, Vol.216, No.12, 2724-2735, 2019.
(Summary)
promotes necroptosis of AEII cells through JNK-mediated up-regulation of Ripk3, highlighting the necroptosis pathway as a therapeutic target for IPF.
Chieko Ishifune, Shin-ichi Tsukumo, Yoichi Maekawa, Katsuto Hozumi, Hyun Doo Chung, Chihiro Motozono, Sho Yamasaki, Hiroyasu Nakano and Koji Yasutomo : Regulation of membrane phospholipid asymmetry by Notch-mediated flippase expression controls the number of intraepithelial TCRαβ+CD8αα+ T cells., PLoS Biology, Vol.17, No.5, 2019.
(Summary)
Intestinal intraepithelial lymphocytes (IELs) expressing CD8αα on αβ T cells (TCRαβ+CD8αα+ IELs) have suppressive capabilities in enterocolitis, but the mechanism that maintains homeostasis and cell number is not fully understood. Here, we demonstrated that the number of TCRαβ+CD8αα+ IELs was severely reduced in mice lacking recombination signal binding protein for immunoglobulin kappa J region (Rbpj) or Notch1 and Notch2 in T cells. Rbpj-deficient TCRαβ+CD8αα+ IELs expressed low levels of Atp8a2, which encodes a protein with flippase activity that regulates phospholipid asymmetry of plasma membrane such as flipping phosphatidylserine in the inner leaflet of plasma membrane. Rbpj-deficient TCRαβ+CD8αα+ IELs cannot maintain phosphatidylserine in the inner leaflet of the plasma membrane. Furthermore, depletion of intestinal macrophages restored TCRαβ+CD8αα+ IELs in Rbpj-deficient mice, suggesting that exposure of phosphatidylserine on the plasma membrane in Rbpj-deficient TCRαβ+CD8αα+ IELs acts as an "eat-me" signal. Together, these results revealed that Notch-Atp8a2 is a fundamental regulator for IELs and highlighted that membrane phospholipid asymmetry controlled by Notch-mediated flippase expression is a critical determinant in setting or balancing the number of TCRαβ+CD8αα+ IELs.
MicroRNAs have broad roles in tumorigenesis and cell differentiation through regulation of target genes. Notch signaling also controls cell differentiation and tumorigenesis. However, the mechanisms through which Notch mediates microRNA expression are still unclear. In this study, we aimed to identify microRNAs regulated by Notch signaling. Our analysis found that microRNA-449a (miR-449a) was indirectly regulated by Notch signaling. Although miR-449a-deficient mice did not show any Notch-dependent defects in immune cell development, treatment of miR-449a-deficient mice with azoxymethane (AOM) or dextran sodium sulfate (DSS) increased the numbers and sizes of colon tumors. These effects were associated with an increase in intestinal epithelial cell proliferation following AOM/DSS treatment. In patients with colon cancer, miR-449a expression was inversely correlated with disease-free survival and histological scores and was positively correlated with the expression of MLH1 for which loss-of function mutations have been shown to be involved in colon cancer. Colon tissues of miR-449a-deficient mice showed reduced Mlh1 expression compared with those of wild-type mice. Thus, these data suggested that miR-449a acted as a key regulator of colon tumorigenesis by controlling the proliferation of intestinal epithelial cells. Additionally, activation of miR-449a may represent an effective therapeutic strategy and prognostic marker in colon cancer.
Sultana Taskia Zaman, Hideki Arimochi, Satoshi Maruyama, Chieko Ishifune, Shin-ichi Tsukumo, Akiko Kitamura and Koji Yasutomo : Notch Balances Th17 and Induced Regulatory T Cell Functions in Dendritic Cells by Regulating Aldh1a2 Expression., The Journal of Immunology, Vol.199, No.6, 1989-1997, 2017.
(Summary)
Dendritic cells (DCs) are important for adaptive immune responses through the activation of T cells. The molecular interplay between DCs and T cells determines the magnitude of T cell responses or outcomes of functional differentiation of T cells. In this study, we demonstrated that DCs in mice that are Rbpj deficient in CD11c(+) cells (Rbpj(-/-) mice) promoted the differentiation of IL-17A-producing Th17 cells. Rbpj-deficient DCs expressed little Aldh1a2 protein that is required for generating retinoic acid. Those DCs exhibited a reduced ability for differentiating regulatory T cells induced by TGF-. Rbpj protein directly regulated Aldh1a2 transcription by binding to its promoter region. The overexpression of Aldh1a2 in Rbpj-deficient DCs negated their Th17-promoting ability. Transfer of naive CD4(+) T cells into Rag1-deficient Rbpj(-/-) mice enhanced colitis with increased Th17 and reduced induced regulatory T cells (iTreg) compared with control Rag1-deficient mice. The cotransfer of iTreg and naive CD4(+) T cells into Rag1-deficient Rbpj(-/-) mice improved colitis compared with transfer of naive CD4(+) T cell alone. Furthermore, cotransfer of DCs from Rbpj(-/-) mice that overexpressed Aldh1a2 or Notch-stimulated DCs together with naive CD4(+) T cells into Rbpj(-/-)Rag1-deficient mice led to reduced colitis with increased iTreg numbers. Therefore, our studies identify Notch signaling in DCs as a crucial balancer of Th17/iTreg, which depends on the direct regulation of Aldh1a2 transcription in DCs.
Takahiro Furukawa, Chieko Ishifune, Shin-ichi Tsukumo, Katsuto Hozumi, Yoichi Maekawa, Naoko Matsui, Ryuji Kaji and Koji Yasutomo : Transmission of survival signals through Delta-like 1 on activated CD4(+) T cells., Scientific Reports, Vol.6, 33692, 2016.
(Summary)
Notch expressed on CD4(+) T cells transduces signals that mediate their effector functions and survival. Although Notch signaling is known to be cis-inhibited by Notch ligands expressed on the same cells, the role of Notch ligands on T cells remains unclear. In this report we demonstrate that the CD4(+) T cell Notch ligand Dll1 transduces signals required for their survival. Co-transfer of CD4(+) T cells from Dll1(-/-) and control mice into recipient mice followed by immunization revealed a rapid decline of CD4(+) T cells from Dll1(-/-) mice compared with control cells. Dll1(-/-) mice exhibited lower clinical scores of experimental autoimmune encephalitis than control mice. The expression of Notch target genes in CD4(+) T cells from Dll1(-/-) mice was not affected, suggesting that Dll1 deficiency in T cells does not affect cis Notch signaling. Overexpression of the intracellular domain of Dll1 in Dll1-deficient CD4(+) T cells partially rescued impaired survival. Our data demonstrate that Dll1 is an independent regulator of Notch-signaling important for the survival of activated CD4(+) T cells, and provide new insight into the physiological roles of Notch ligands as well as a regulatory mechanism important for maintaining adaptive immune responses.
Yoichi Maekawa, Chieko Ishifune, Shin-ichi Tsukumo, Katsuto Hozumi, Hideo Yagita and Koji Yasutomo : Notch controls the survival of memory CD4+ T cells by regulating glucose uptake., Nature Medicine, Vol.21, No.1, 55-61, 2015.
(Summary)
CD4+ T cells differentiate into memory T cells that protect the host from subsequent infection. In contrast, autoreactive memory CD4+ T cells harm the body by persisting in the tissues. The underlying pathways controlling the maintenance of memory CD4+ T cells remain undefined. We show here that memory CD4+ T cell survival is impaired in the absence of the Notch signaling protein known as recombination signal binding protein for immunoglobulin J region (Rbpj). Treatment of mice with a Notch inhibitor reduced memory CD4+ T cell numbers and prevented the recurrent induction of experimental autoimmune encephalomyelitis. Rbpj-deficient CD4+ memory T cells exhibit reduced glucose uptake due to impaired AKT phosphorylation, resulting in low Glut1 expression. Treating mice with pyruvic acid, which bypasses glucose uptake and supplies the metabolite downstream of glucose uptake, inhibited the decrease of autoimmune memory CD4+ T cells in the absence of Notch signaling, suggesting memory CD4+ T cell survival relies on glucose metabolism. Together, these data define a central role for Notch signaling in maintaining memory CD4+ T cells through the regulation of glucose uptake.
(Keyword)
Animals / CD4-Positive T-Lymphocytes / Glucose / Glucose Transporter Type 1 / Humans / Immunoglobulin J Recombination Signal Sequence-Binding Protein / Mice / Oncogene Protein v-akt / Receptors, Antigen, T-Cell / Receptors, Notch / Signal Transduction
Hiroyuki Kose, Tohru Sakai, Shin-ichi Tsukumo, Kaichun Wei, Takahisa Yamada, Koji Yasutomo and Kozo Matsumoto : Maturational arrest of thymocyte development is caused by a deletion in the receptor-like protein tyrosine phosphatase κ gene in LEC rats, Genomics, Vol.89, No.6, 673-677, 2007.
(Summary)
The Long-Evans Cinnamon (LEC) rat has a spontaneous mutation, T helper immunodeficiency (thid), which causes a markedly reduced CD4(+) thymocyte population. Here we positionally clone the locus and identify a deletion in the gene encoding a receptor-like protein tyrosine phosphatase kappa (Ptprk) that led to complete loss of the transcript. The rat Ptprk gene exhibits 98% identity with the human and mouse counterparts and is expressed most abundantly in the CD4(-)CD8(-) double-negative stage. The downregulation of Ptprk in mouse immature thymocytes by RNA interference mimicked the thid phenotype. These results indicate that thid maps to the Ptprk locus and that functional Ptprk is crucial for lineage commitment or progression of CD4(+) T cells. We also found that Ptprk appears to function in parallel with or downstream of Th-POK/cKrox (also known as ZBTB7B), a master regulator of T cell lineage decision.
(Keyword)
T cell differentiation / Protein phosphatase / LEC rat / Thymus / Th-POK/cKrox
Yuki Hayashi, Naozumi Ishimaru, Rieko Arakaki, Shin-ichi Tsukumo, Hitomi Fukui, Kenji Kishihara, Hiroshi Shiota, Koji Yasutomo and Yoshio Hayashi : Effective Treatment of a Mouse Model of Sjogren's Syndrome With Eyedrop Administrasiton of Anti-CD4 Monoclonal Antibody, Arthritis and Rheumatism, Vol.50, No.9, 2903-2910, 2004.
(Summary)
To determine whether eyedrop administration of an anti-CD4 monoclonal antibody (mAb) is effective in the treatment of Sjögren's syndrome (SS) using a mouse model of the disease. The anti-CD4 mAb was administered daily into the eyes of mice with SS from ages 4 to 8 weeks or ages 10 to 12 weeks. During treatment, tear volume was monitored and after final treatment, histologic features of the lacrimal and salivary glands, the phenotypes and function of T cells, and serum titers of anti-alpha-fodrin antibody were examined. Eyedrop administration of anti-CD4 mAb before the onset of SS prevented the autoimmune pathology seen in the lacrimal glands but not that in the salivary glands. Furthermore, eyedrop administration of anti-CD4 mAb after the development of SS inhibited mononuclear cell infiltration and the destruction of parenchyma only in the lacrimal glands. Eyedrop administration of anti-CD4 mAb suppressed the local activation of CD4+ T cells rather than deleting CD4+ T cells, which reduced the expansion of pathologic CD4+ T cells against alpha-fodrin. These results demonstrate the remarkable efficacy of anti-CD4 mAb eyedrops in the treatment of SS eye symptoms, which illustrates a new antibody-based therapeutic strategy for patients with eye problems caused by SS as well as other diseases.
Yuki Hayashi, Shin-ichi Tsukumo, Hiroshi Shiota, Kenji Kishihara and Koji Yasutomo : Antigen-Specific T Cell Repertoire Modification of CD4+CD25+ Regulatory T Cells, The Journal of Immunology, Vol.172, No.9, 5240-5248, 2004.
(Summary)
T cell immune responses are regulated by the interplay between effector and suppressor T cells. Immunization with Ag leads to the selective expansion and survival of effector CD4(+) T cells with high affinity TCR against the Ag and MHC. However, it is not known if CD4(+)CD25(+) regulatory T cells (T(reg)) recognize the same Ag as effector T cells or whether Ag-specific TCR repertoire modification occurs in T(reg). In this study, we demonstrate that after a primary Ag challenge, T(reg) proliferate and TCR repertoire modification is observed although both of these responses were lower than those in conventional T cells. The repertoire modification of Ag-specific T(reg) after primary Ag challenge augmented the total suppressive function of T(reg) against TCR repertoire modification but not against the proliferation of memory CD4(+) T cells. These results reveal that T cell repertoire modification against a non-self Ag occurs in T(reg), which would be crucial for limiting excess primary and memory CD4(+) T cell responses. In addition, these studies provide evidence that manipulation of Ag-specific T(reg) is an ideal strategy for the clinical use of T(reg).
Yoichi Maekawa, Shin-ichi Tsukumo, Okada Hiroko, Kenji Kishihara and Koji Yasutomo : Breakdown of peripheral T-cell tolerance by chronic IL-15 elevation, Transplantation, Vol.76, No.2, 415-420, 2003.
(Summary)
Thymic deletion purges the repertoire of most developing T cells with the potential for overt self-reactivity, but some self-specific cells do emerge into the peripheral pool. Under most conditions, these potentially autoaggressive cells remain in a quiescent state. However, in some circumstances, they become activated and acquire effector function, leading to immune disease. It is thus important to clarify the mechanism(s) responsible for determining the balance between such inappropriate T-cell activation and the normal state of peripheral tolerance. In this article, we show that chronic elevation of interleukin-15 levels interferes with the tolerant state of CD8+ T cells through a process that involves activation of nonlymphoid antigen-presenting cells by CD4+asialo-GM1+ (ASGM1) or both CD4+ASGM1- and CD4-ASGM1+ cells. These findings suggest a potential role for dysregulated interleukin-15 production in promoting tolerance breakdown. This new information may be of potential use in improving tumor vaccines to self-antigens and in ameliorating autoimmune or graft-versus-host disease.
Shin-ichi Tsukumo and Koji Yasutomo : The regulation of metabolic pathway by Notch signaling, Science of the Living Body, Vol.70, No.2, 109-113, Mar. 2019.
(Link to Search Site for Scientific Articles)
● CiNii @ National Institute of Informatics (NAID): 40021880949
Chieko Ishifune, Shin-ichi Tsukumo and Koji Yasutomo : Notch signal controls the number of TCR+CD8+ intraepithelial lymphocytes via phospholipid asymmetry by maintaining flippase ATP8a2, Australia-Japan Meeting on Cell Death, Tokyo, May 2018.
Proceeding of Domestic Conference:
1.
Shin-ichi Tsukumo, Yoichi Maekawa and Koji Yasutomo : Aff3 is required for the class switching of IgG2c, IgG1 and IgG3 in a B cell-intrinsic manner, 第48回 日本免疫学会学術集会, Dec. 2019.
2.
Shin-ichi Tsukumo and Koji Yasutomo : Transcriptional elongation factor Aff3 regulates class switching of antibody in B cells, 第47回 日本免疫学会学術集会, Dec. 2018.
3.
Shin-ichi Tsukumo and Koji Yasutomo : 自己免疫疾患におけるAFFファミリーの役割, 第33回自己免疫研究会, Jul. 2018.
4.
Chieko Ishifune, Shin-ichi Tsukumo and Koji Yasutomo : Notch signal controls the number of TCRab+CD8aa+ intraepithelial lymphocytes via phospholipid asymmetry by maintaining flippase ATP8a2, 第46回 日本免疫学会学術集会, Dec. 2017.
5.
Shin-ichi Tsukumo and Koji Yasutomo : DNA結合因子 CTCFのCD4 T細胞における役割, 第31回自己免疫研究会, Jul. 2016.
6.
Shin-ichi Tsukumo and Koji Yasutomo : Function of Notch-Rbpj pathway in naive CD8 T cells, 第44回日本免疫学会学術集会, Nov. 2015.
7.
Shin-ichi Tsukumo and Koji Yasutomo : Notch-Rbpj target genes for maintaining naive and memory T cells, 第43回 日本免疫学会学術集会, Dec. 2014.