76
|
Revy P, Muto T, Levy Y, Geissmann F, Plebani A, Sanal O, Catalan N, Forveille M, Dufourcq-Labelouse R, Gennery A, Tezcan I, Ersoy F, Kayserili H, Ugazio AG, Brousse N, Muramatsu M, Notarangelo LD, Kinoshita K, Honjo T, Fischer A, Durandy A. Activation-induced cytidine deaminase (AID) deficiency causes the autosomal recessive form of the Hyper-IgM syndrome (HIGM2). Cell 2000; 102:565-75. [PMID: 11007475 DOI: 10.1016/s0092-8674(00)00079-9] [Citation(s) in RCA: 1187] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The activation-induced cytidine deaminase (AID) gene, specifically expressed in germinal center B cells in mice, is a member of the cytidine deaminase family. We herein report mutations in the human counterpart of AID in patients with the autosomal recessive form of hyper-IgM syndrome (HIGM2). Three major abnormalities characterize AID deficiency: (1) the absence of immunoglobulin class switch recombination, (2) the lack of immunoglobulin somatic hypermutations, and (3) lymph node hyperplasia caused by the presence of giant germinal centers. The phenotype observed in HIGM2 patients (and in AID-/- mice) demonstrates the absolute requirement for AID in several crucial steps of B cell terminal differentiation necessary for efficient antibody responses.
Collapse
|
77
|
Nakashiba T, Ikeda T, Nishimura S, Tashiro K, Honjo T, Culotti JG, Itohara S. Netrin-G1: a novel glycosyl phosphatidylinositol-linked mammalian netrin that is functionally divergent from classical netrins. J Neurosci 2000; 20:6540-50. [PMID: 10964959 PMCID: PMC6772945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
UNC-6/netrins compose a small phylogenetically conserved family of proteins that act as axon guidance cues. With a signal sequence trap method, we isolated a cDNA encoding a novel member of the UNC-6/netrin family, which we named netrin-G1. Unlike classical netrins, netrin-G1 consists of at least six isoforms of which five were predominantly anchored to the plasma membrane via glycosyl phosphatidyl-inositol linkages. Netrin-G1 transcripts were first detected in midbrain and hindbrain regions by embryonic day 12 and reached highest levels at perinatal stages in various brain regions, including olfactory bulb mitral cells, thalamus, and deep cerebellar nuclei. Its expression was primarily restricted to the CNS. Interestingly, netrin-G1 proteins did not show appreciable affinity to any netrin receptor examined. Unlike netrin-1, a secreted form of netrin-G1 consistently failed to attract circumferentially growing axons from the cerebellar plate. Our findings suggest that netrin-G1 and its putative receptors have coevolved independently from the classical netrins. The expression pattern of netrin-G1 and its predicted neuronal membrane localization suggest it may also have novel signaling functions in nervous system development.
Collapse
|
78
|
Muramatsu M, Kinoshita K, Fagarasan S, Yamada S, Shinkai Y, Honjo T. Class switch recombination and hypermutation require activation-induced cytidine deaminase (AID), a potential RNA editing enzyme. Cell 2000; 102:553-63. [PMID: 11007474 DOI: 10.1016/s0092-8674(00)00078-7] [Citation(s) in RCA: 2560] [Impact Index Per Article: 106.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Induced overexpression of AID in CH12F3-2 B lymphoma cells augmented class switching from IgM to IgA without cytokine stimulation. AID deficiency caused a complete defect in class switching and showed a hyper-IgM phenotype with enlarged germinal centers containing strongly activated B cells before or after immunization. AID-/- spleen cells stimulated in vitro with LPS and cytokines failed to undergo class switch recombination although they expressed germline transcripts. Immunization of AID-/- chimera with 4-hydroxy-3-nitrophenylacetyl (NP) chicken gamma-globulin induced neither accumulation of mutations in the NP-specific variable region gene nor class switching. These results suggest that AID may be involved in regulation or catalysis of the DNA modification step of both class switching and somatic hypermutation.
Collapse
|
79
|
Muto T, Muramatsu M, Taniwaki M, Kinoshita K, Honjo T. Isolation, tissue distribution, and chromosomal localization of the human activation-induced cytidine deaminase (AID) gene. Genomics 2000; 68:85-8. [PMID: 10950930 DOI: 10.1006/geno.2000.6268] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The gene encoding activation-induced cytidine deaminase (AID), a member of the cytidine deaminase family, was isolated from a murine B cell lymphoma line, CH12F3-2, induced by combined stimulation of TGF-beta, IL-4, and CD40L. We have isolated the human orthologue of mouse AID cDNA, which has an open reading frame of 198 residues containing a conserved cytidine deaminase motif. The amino acid sequence of human AID is 92% identical to that of mouse AID. RT-PCR analysis of 15 human tissues showed that AID mRNA is expressed strongly in lymph nodes and tonsils. The complete human AID gene consisting of five exons was isolated and mapped to chromosome 12p13 by fluorescence in situ hybridization.
Collapse
MESH Headings
- Amino Acid Sequence
- Blotting, Northern
- Cell Line
- Chromosome Mapping
- Chromosomes, Human, Pair 12/genetics
- Cytidine Deaminase/genetics
- DNA/chemistry
- DNA/genetics
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Complementary/isolation & purification
- Female
- Gene Expression
- HeLa Cells
- Humans
- In Situ Hybridization, Fluorescence
- Jurkat Cells
- Molecular Sequence Data
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Tissue Distribution
- Tumor Cells, Cultured
Collapse
|
80
|
Abstract
We have studied the expansion, activation, homing and antibody production of B1 cells in two different mouse models. One is the HL transgenic mouse, which carries Ig genes encoding the anti-red blood cell autoantibody (4C8) and develops autoimmune hemolytic anemia by the activation of autoreactive B1 cells that escape from clonal deletion and expand in the peritoneal cavity (PEC). The other model is represented by alymphoplasia (aly) mice, which carry a point mutation in the gene encoding NF-kappaB-inducing kinase (NIK) and have drastically reduced immunoglobulin serum levels, in spite of their peritoneal cavity containing a large number of B1 cells. We have found that a) expression levels of the B-cell antigen receptor (BCR) influence the size of the B1 -cell compartment and efficiency of allelic exclusion and B2-cell deletion; b) antibody production of B1 cells is closely related with their migration from PEC to other lymphoid organs and is dependent on NIK; and c) infection, lipopolysaccharide stimulation, cytokine administration or T-cell activation by noncanonical antigens induces migration and differentiation of peritoneal B1 cells into antibody-producing cells. We describe a scenario where most of B1 and B2 differences are due to a distinct activation threshold of BCR and antigen repertoire.
Collapse
MESH Headings
- Anemia, Hemolytic, Autoimmune/genetics
- Anemia, Hemolytic, Autoimmune/immunology
- Animals
- Autoantibodies/biosynthesis
- B-Lymphocyte Subsets/cytology
- B-Lymphocyte Subsets/immunology
- Cell Division
- Cell Movement
- Chemotaxis, Leukocyte
- Erythrocytes/immunology
- Lymphocyte Activation
- Mice
- Mice, Mutant Strains
- Mice, Transgenic
- Models, Biological
- Receptors, Antigen, T-Cell, gamma-delta/metabolism
- T-Lymphocyte Subsets/immunology
Collapse
|
81
|
Kamata T, Nogaki F, Fagarasan S, Sakiyama T, Kobayashi I, Miyawaki S, Ikuta K, Muso E, Yoshida H, Sasayama S, Honjo T. Increased frequency of surface IgA-positive plasma cells in the intestinal lamina propria and decreased IgA excretion in hyper IgA (HIGA) mice, a murine model of IgA nephropathy with hyperserum IgA. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:1387-94. [PMID: 10903742 DOI: 10.4049/jimmunol.165.3.1387] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Because abnormalities of mucosal immunity have been suggested in human IgA nephropathy, we examined the involvement of mucosal immunity in IgA deposition to the kidney in hyper IgA (HIGA) mice, which was established as a mouse model for human IgA nephropathy with hyperserum IgA. The number of surface IgA+B220- lymphocytes in the intestinal lamina propria (LP) of HIGA mice increased 2.7-fold at 30 wk of age as compared with those at 10 wk of age, whereas normal mice did not show such increase. The surface IgA+B220- LP lymphocytes spontaneously secreted IgA in culture. Morphological studies showed that the surface IgA+B220- lymphocytes of murine intestinal LP are identical with plasma cells (PCs). About 20% of IgA+B220- PC in LP expressed both Mac-1 and CD19, suggesting that they may derive from peritoneal B-1 cells. Cell cycle study on intestinal IgA-PCs using bromodeoxyuridine revealed no difference between HIGA mice and normal mice, suggesting that the high frequency of IgA-producing PCs in HIGA mice is not due to enhanced proliferation or prolonged survival of IgA-producing PCs in LP. In addition, IgA secretion into the gut lumen of HIGA mice decreased drastically (to one forth) with aging. These data suggest that the increased number of intestinal IgA-producing PCs and the down-regulation of IgA excretion into the intestinal lumen might synergistically contribute to the hyperserum IgA in HIGA mice and resultant IgA deposition to the kidney.
Collapse
MESH Headings
- Animals
- Cell Cycle/immunology
- Feces/chemistry
- Female
- Glomerulonephritis, IGA/blood
- Glomerulonephritis, IGA/immunology
- Glomerulonephritis, IGA/metabolism
- Immunoglobulin A/biosynthesis
- Immunoglobulin A/blood
- Immunoglobulin A/metabolism
- Intestinal Mucosa/cytology
- Intestinal Mucosa/immunology
- Intestinal Mucosa/metabolism
- Leukocyte Common Antigens/biosynthesis
- Lymphocyte Count
- Lymphocyte Subsets/immunology
- Lymphocyte Subsets/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Plasma Cells/immunology
- Plasma Cells/metabolism
- RNA, Messenger/biosynthesis
- Receptors, Antigen, B-Cell/biosynthesis
- Receptors, Antigen, B-Cell/blood
- Receptors, Polymeric Immunoglobulin/biosynthesis
- Receptors, Polymeric Immunoglobulin/genetics
- Species Specificity
Collapse
|
82
|
Kato K, Morrison AM, Nakano T, Tashiro K, Honjo T. ESOP-1, a secreted protein expressed in the hematopoietic, nervous, and reproductive systems of embryonic and adult mice. Blood 2000; 96:362-4. [PMID: 10891475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
To isolate soluble factors expressed in early phases of hematopoietic differentiation, we applied the signal sequence trap method to the in vitro murine hematopoietic differentiation system, in which ES cells are cocultured with OP-9 stroma cells. This strategy allowed us to isolate cDNA for a secreted protein, ESOP-1, of 160 amino acids, the sequence of which shows 64% identity with human ESOP-1/MD-2. ESOP-1 mRNA was highly expressed in the mouse embryos at 7.5 days after coitus. Expression of the ESOP-1 mRNA and protein was shown in the embryonic and adult hematopoietic system. In addition, the ESOP-1 protein was found in the yolk sac-blood islands, the developing nervous system, and the adult reproductive system. These results suggest that ESOP-1 may play some roles in the development or maintenance of hematopoietic, nervous, and reproductive systems.
Collapse
|
83
|
Kurooka H, Honjo T. Functional interaction between the mouse notch1 intracellular region and histone acetyltransferases PCAF and GCN5. J Biol Chem 2000; 275:17211-20. [PMID: 10747963 DOI: 10.1074/jbc.m000909200] [Citation(s) in RCA: 191] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Notch receptor that plays an important role in cell fate determination is intracellularly cleaved by interaction with the ligand. The cleaved intracellular region (RAMIC) of Notch is translocated into the nucleus and interacts with a DNA-binding protein RBP-J to activate transcription of genes that regulate cell differentiation. Although RAMIC has been shown to facilitate the RBP-J-mediated transactivation by displacing the histone deacetylase corepressor complex from RBP-J, there is no evidence demonstrating the involvement of histone acetyltransferases (HATs) in the transactivation. Here we show that mouse Notch1 RAMIC interacts with two conserved HATs, mouse PCAF and GCN5, and recruits each of the HATs to RBP-J. The ankyrin repeats and the transactivation domain of RAMIC and the N-terminal regions of PCAF and GCN5, respectively, are required for the interaction. We also show that not only mouse Notch1 but also Drosophila Notch RAMIC interacts with mouse PCAF and GCN5 in mammalian cells. Furthermore, the RBP-J-mediated transactivation activity of RAMIC is repressed by two HAT inhibitor proteins, E1A and Twist. These results suggest that HATs including PCAF and GCN5 play an important role in the RBP-J-mediated transactivation by RAMIC.
Collapse
|
84
|
Hossain KZ, Honjo T. Separation of trace amounts of palladium (II) with crown ether from hydrochloric acid and potassium thiocyanate media. FRESENIUS' JOURNAL OF ANALYTICAL CHEMISTRY 2000; 367:141-5. [PMID: 11225873 DOI: 10.1007/s002160051614] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new method for the separation of trace amounts of palladium from hydrochloric acid and potassium thiocyanate media has been established based on the formation of an ion-pair complex of palladium thiocyanate anion Pd(SCN)4(2-) and the cationic potassium complex of dicyclohexyl- 18-crown-6 (DC18C6) in chloroform. The effect of various factors (solvent, crown ether, potassium thiocyanate, hydrochloric acid, reagent concentration, shaking time, phase volume ratio, composition of the extracted species, foreign ions, etc.) on the extraction and back-extraction of palladium has been investigated. The method can be combined with subsequent FAAS determination of palladium. The procedure was applied to determine palladium traces in chloroplatinic acid and rhodium chloride.
Collapse
|
85
|
|
86
|
Ono SJ, Zhou G, Tai AK, Inaba M, Kinoshita K, Honjo T. Identification of a stimulus-dependent DNase I hypersensitive site between the Ialpha and Calpha exons during immunoglobulin heavy chain class switch recombination. FEBS Lett 2000; 467:268-72. [PMID: 10675552 DOI: 10.1016/s0014-5793(00)01151-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The complete humoral response to foreign antigen depends upon two distinct recombination events within the heavy chain locus of immunoglobulin. The first recombination event takes place in what will become the antigen combining site of the antibody molecule, encoded by V, D and J segments. The second recombination event involves the looping-out of large spans of DNA which separate the various clusters of heavy chain exons which define the different immunoglobulin isotypes, or classes. While a great deal has been learned about the nature of the VDJ recombinase, very little is known about the nature of the class-switch recombinase. Using a cell system where class-switch recombination occurs primarily to the IgA locus, we have looked for stimulus-dependent changes in the chromatin structure of the IgA locus which might result from interactions between components of the recombinase and cis-elements within the region. We present evidence that strongly suggests that the class-switch recombinase interacts between the Ialpha and Calpha exons of IgA, just upstream of the highly reiterated DR1 and DR2 elements. However, although multiple potential SMAD-4 sites are located precisely within the DNase I hypersensitive site and 160 bp upstream of that site, we failed to detect any evidence of DNA/protein interactions near the hypersensitive site. Moreover, recombinant SMAD-3/4 proteins fail to interact with these sites with appreciable affinity in vitro. These data suggest that some other structural alteration at this site (e.g. RNA/DNA hybrid) may mediate the nuclease sensitivity.
Collapse
|
87
|
Garceau N, Kosaka Y, Masters S, Hambor J, Shinkura R, Honjo T, Noelle RJ. Lineage-restricted function of nuclear factor kappaB-inducing kinase (NIK) in transducing signals via CD40. J Exp Med 2000; 191:381-6. [PMID: 10637282 PMCID: PMC2195761 DOI: 10.1084/jem.191.2.381] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/1999] [Accepted: 10/14/1999] [Indexed: 01/09/2023] Open
Abstract
CD40 signaling in B cells and dendritic cells (DCs) is critical for the development of humoral and cell-mediated immunity, respectively. Nuclear factor kappaB (NF-kappaB)-inducing kinase (NIK) has been implicated as a central transducing kinase in CD40-dependent activation. Here, we show that although NIK is essential for B cell activation, it is dispensable for activation of DCs. Such data provide compelling evidence that different intermediary kinases are used by different cellular lineages to trigger NF-kappaB activation via CD40.
Collapse
|
88
|
Fagarasan S, Shinkura R, Kamata T, Nogaki F, Ikuta K, Honjo T. Mechanism of B1 cell differentiation and migration in GALT. Curr Top Microbiol Immunol 2000; 252:221-9. [PMID: 11125479 DOI: 10.1007/978-3-642-57284-5_23] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
|
89
|
Nisitani S, Honjo T. Breakage of B cell tolerance and autoantibody production in anti-erythrocyte transgenic mice. Int Rev Immunol 1999; 18:259-70. [PMID: 10614728 DOI: 10.3109/08830189909043029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In summary, there are two pathways for activation of peritoneal B-1 cells in HL mice: T cell-dependent and T cell-independent pathways. In both pathways, IL-10 is suggested to play an important role (Fig. 1). We have not yet known what type of cells secrete IL-10 by and whether other soluble factors are involved in each pathway. These questions are to be elucidated by further studies on HL mice.
Collapse
|
90
|
Ochi H, Takeshita H, Suda T, Nisitani S, Honjo T, Watanabe T. Regulation of B-1 cell activation and its autoantibody production by Lyn kinase-regulated signallings. Immunology 1999; 98:595-603. [PMID: 10594694 PMCID: PMC2326971 DOI: 10.1046/j.1365-2567.1999.00899.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The src-family protein tyrosine kinase, Lyn, has been reported to play a crucial role in the regulation of B-cell antigen receptor (BCR)-mediated signalling. To elucidate the role of Lyn in the maintenance of immunological tolerance and the prevention of B-1 cell activation and its autoantibody production, Lyn-deficient mice were crossed with transgenic mice carrying the immunoglobulin heavy and light chain genes encoding an autoantibody against mouse red blood cells. In the transgenic mice, most peripheral B cells expressed the B-1 cell phenotype. When the transgenic mice were bred in specific pathogen-free (SPF) conditions, B-1 cells were anergic and did not produce any autoantibody. In contrast, Lyn-deficient transgenic mice kept in the same SPF conditions revealed markedly increased numbers of activated B-1 cells and developed severe autoimmune haemolytic anaemia. Moreover, the mice had a huge splenomegaly containing a remarkable accumulation of erythroblasts, resulted from extramedullary erythropoiesis, in addition to the increased numbers of lymphoblast-like cells of the B-1 cell lineages. The present study demonstrates a crucial role of Lyn kinase in the regulation of B-1 cell activation and maintenance of tolerance.
Collapse
|
91
|
Minoguchi S, Ikeda T, Itohara S, Kaneko T, Okaichi H, Honjo T. Studies on the cell-type specific expression of RBP-L, a RBP-J family member, by replacement insertion of beta-galactosidase. J Biochem 1999; 126:738-47. [PMID: 10502683 DOI: 10.1093/oxfordjournals.jbchem.a022511] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The RBP-L gene encodes a DNA binding protein that is structurally related to RBP-J, the mammalian homolog of Drosophila Suppressor of Hairless. Although the RBP-L protein binds the same DNA sequence as RBP-J, the in vivo function of this protein remains largely unknown. In order to investigate the role of this protein, we generated RBP-L mutant mice by targeted disruption involving replacement of the protein-coding sequence in the first exon with an in-frame fusion of the nlacZ cDNA. The homozygous mutant mice appeared morphologically normal and fertile. Unexpectedly, we found the possible existence of additional promoter(s) downstream of the first exon whose activity was not fully disrupted in the mutant mice. The promoter upstream of the first exon is regulated in a cell type-specific manner so that transcription is active in neurons but almost inactive in lung where the downstream promoter is active. The specific expression of the beta-galactosidase fusion protein was detected in layer VI of the cerebral cortex, in the pyramidal cell layer of the hippocampus, and in the granule cell layer of the dentate gyrus. Furthermore, we found that the upstream promoter activity in neurons might be regulated by some neuronal activity.
Collapse
|
92
|
Apelqvist A, Li H, Sommer L, Beatus P, Anderson DJ, Honjo T, Hrabe de Angelis M, Lendahl U, Edlund H. Notch signalling controls pancreatic cell differentiation. Nature 1999; 400:877-81. [PMID: 10476967 DOI: 10.1038/23716] [Citation(s) in RCA: 866] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The pancreas contains both exocrine and endocrine cells, but the molecular mechanisms controlling the differentiation of these cell types are largely unknown. Despite their endodermal origin, pancreatic endocrine cells share several molecular characteristics with neurons, and, like neurons in the central nervous system, differentiating endocrine cells in the pancreas appear in a scattered fashion within a field of progenitor cells. This indicates that they may be generated by lateral specification through Notch signalling. Here, to test this idea, we analysed pancreas development in mice genetically altered at several steps in the Notch signalling pathway. Mice deficient for Delta-like gene 1 (Dll1) or the intracellular mediator RBP-Jkappa showed accelerated differentiation of pancreatic endocrine cells. A similar phenotype was observed in mice over-expressing neurogenin 3 (ngn 3) or the intracellular form of Notch3 (a repressor of Notch signalling). These data provide evidence that ngn3 acts as proendocrine gene and that Notch signalling is critical for the decision between the endocrine and progenitor/exocrine fates in the developing pancreas.
Collapse
|
93
|
Nakamura T, Ruiz-Lozano P, Lindner V, Yabe D, Taniwaki M, Furukawa Y, Kobuke K, Tashiro K, Lu Z, Andon NL, Schaub R, Matsumori A, Sasayama S, Chien KR, Honjo T. DANCE, a novel secreted RGD protein expressed in developing, atherosclerotic, and balloon-injured arteries. J Biol Chem 1999; 274:22476-83. [PMID: 10428823 DOI: 10.1074/jbc.274.32.22476] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We have identified and characterized mouse, rat, and human cDNAs that encode a novel secreted protein of 448 amino acids named DANCE (developmental arteries and neural crest epidermal growth factor (EGF)-like). DANCE contains six calcium-binding EGF-like domains, one of which includes an RGD motif. Overexpression studies of recombinant DANCE protein document that DANCE is a secreted 66-kDa protein. DANCE and recently described protein S1-5 comprise a new EGF-like protein family. The human DANCE gene was mapped at chromosome 14q32.1. DANCE mRNA is mainly expressed in heart, ovary, and colon in adult human tissues. Expression profile analysis by in situ hybridization revealed prominent DANCE expression in developing arteries. DANCE is also expressed in neural crest cell derivatives, endocardial cushion tissue, and several other mesenchymal tissues. In adult vessels, DANCE expression is largely diminished but is reinduced in balloon-injured vessels and atherosclerotic lesions, notably in intimal vascular smooth muscle cells and endothelial cells that lose their ability to proliferate in late stage of injury. DANCE protein was shown to promote adhesion of endothelial cells through interaction of integrins and the RGD motif of DANCE. DANCE is thus a novel vascular ligand for integrin receptors and may play a role in vascular development and remodeling.
Collapse
|
94
|
Ye SK, Maki K, Kitamura T, Sunaga S, Akashi K, Domen J, Weissman IL, Honjo T, Ikuta K. Induction of germline transcription in the TCRgamma locus by Stat5: implications for accessibility control by the IL-7 receptor. Immunity 1999; 11:213-23. [PMID: 10485656 DOI: 10.1016/s1074-7613(00)80096-5] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
IL-7 receptor (IL-7R) plays critical roles in lymphocyte development by promoting survival and proliferation and by inducing V(D)J recombination in TCR and Ig loci. Here, we demonstrate that IL-7R-activated Stat5 binds to consensus motifs in the 5' regions of Jgamma segments and induces germline transcripts. We also show that a constitutively active form of Stat5 restores V-J recombination of TCRgamma genes and partially rescues T cell development from IL-7R(-/-) T cell precursors, especially in favor of gammadelta T cells. Therefore, this study reveals a potential role of Stat5 in T cell development and also implies that IL-7R may control the accessibility of the TCRgamma locus through Stat5-induced germline transcription.
Collapse
|
95
|
Nishimura H, Nose M, Hiai H, Minato N, Honjo T. Development of lupus-like autoimmune diseases by disruption of the PD-1 gene encoding an ITIM motif-carrying immunoreceptor. Immunity 1999; 11:141-51. [PMID: 10485649 DOI: 10.1016/s1074-7613(00)80089-8] [Citation(s) in RCA: 1914] [Impact Index Per Article: 76.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PD-1, a 55 kDa transmembrane protein containing an immunoreceptor tyrosine-based inhibitory motif, is induced in lymphocytes and monocytic cells following activation. Aged C57BL/6(B6)-PD-1(-/-) congenic mice spontaneously developed characteristic lupus-like proliferative arthritis and glomerulonephritis with predominant IgG3 deposition, which were markedly accelerated by introduction of a Fas mutation (lpr). Introduction of a PD-1 null mutation into the 2C-TCR (anti-H-2Ld) transgenic mice of the H-2(b/d) background resulted in the chronic and systemic graft-versus-host-like disease. Furthermore, CD8+ 2C-TCR+ PD-1(-/-) T cells exhibited markedly augmented proliferation in vitro in response to H-2d allogenic cells. Collectively, it is suggested that PD-1 is involved in the maintenance of peripheral self-tolerance by serving as a negative regulator of immune responses.
Collapse
|
96
|
Lee JS, Ishimoto A, Honjo T, Yanagawa S. Murine leukemia provirus-mediated activation of the Notch1 gene leads to induction of HES-1 in a mouse T lymphoma cell line, DL-3. FEBS Lett 1999; 455:276-80. [PMID: 10437788 DOI: 10.1016/s0014-5793(99)00901-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Constitutive activation of Notch signaling is known to be associated with tumorigenesis. In a mouse T lymphoma cell line, DL-3, we found that a murine leukemia provirus was inserted in the Notch1 locus, which led to marked expression of a virus-Notch1 fusion mRNA encoding an intracellular portion of the Notch1 protein. Furthermore, expression and nuclear localization of this constitutively active form of Notch1 protein were confirmed. Corresponding to this finding, the transcription of the hairy/enhancer of split (HES-1) gene, a known target of Notch1 signaling, was elevated in this cell line. A potential role for overexpressed HES-1 in the development of the lymphoma was discussed.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Basic Helix-Loop-Helix Transcription Factors
- DNA, Complementary/genetics
- DNA, Neoplasm/genetics
- DNA, Viral/genetics
- Gene Expression Regulation, Neoplastic
- Gene Expression Regulation, Viral
- Gene Rearrangement
- Genes, Homeobox
- Homeodomain Proteins/genetics
- Leukemia Virus, Murine/genetics
- Leukemia Virus, Murine/pathogenicity
- Lymphoma, T-Cell/genetics
- Lymphoma, T-Cell/virology
- Membrane Proteins/genetics
- Mice
- Molecular Sequence Data
- Proviruses/genetics
- Proviruses/pathogenicity
- Receptor, Notch1
- Receptors, Cell Surface
- Transcription Factor HES-1
- Transcription Factors
- Tumor Cells, Cultured
Collapse
|
97
|
Hagiyama H, Adachi T, Yoshida T, Nomura T, Miyasaka N, Honjo T, Tsubata T. Signaling through the antigen receptor of B lymphocytes activates a p53-independent pathway of c-Myc-induced apoptosis. Oncogene 1999; 18:4091-8. [PMID: 10435590 DOI: 10.1038/sj.onc.1202772] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Deregulated expression of c-Myc has been shown to induce or enhance apoptosis in various different cell types. c-Myc requires p53 for apoptosis in some but not all the cell types, indicating heterogeneous mechanisms for c-Myc-induced apoptosis. In B lymphoma line WEHI-231, stable expression of c-Myc has been demonstrated to protect cells from BCR-mediated apoptosis. However, stable expression of c-Myc carrying pro-apoptotic functions may generate variant cells resistant to apoptosis. By utilizing an inducible system for c-Myc, we demonstrated here that deregulated expression of c-Myc induced apoptosis of WEHI-231 by itself, indicating that c-Myc induces apoptosis in WEHI-231 as is the case for other cell types. When transactivation of p53 was inactivated, WEHI-231 cells overexpressing c-Myc no longer underwent apoptosis in the absence of other stimuli, but showed markedly enhanced apoptosis in the presence of BCR ligation. These results indicate that deregulated c-Myc expression enhances apoptosis by a p53-independent pathway in the presence of BCR signaling but requires p53 for apoptosis in the absence of BCR crosslinking in WEHI-231. BCR ligation may thus activate a p53-independent pathway of c-Myc-induced apoptosis.
Collapse
|
98
|
Muramatsu M, Sankaranand VS, Anant S, Sugai M, Kinoshita K, Davidson NO, Honjo T. Specific expression of activation-induced cytidine deaminase (AID), a novel member of the RNA-editing deaminase family in germinal center B cells. J Biol Chem 1999; 274:18470-6. [PMID: 10373455 DOI: 10.1074/jbc.274.26.18470] [Citation(s) in RCA: 866] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have identified a novel gene referred to as activation-induced deaminase (AID) by subtraction of cDNAs derived from switch-induced and uninduced murine B lymphoma CH12F3-2 cells, more than 80% of which switch exclusively to IgA upon stimulation. The amino acid sequence encoded by AID cDNA is homologous to that of apolipoprotein B (apoB) mRNA-editing enzyme, catalytic polypeptide 1 (APOBEC-1), a type of cytidine deaminase that constitutes a catalytic subunit for the apoB mRNA-editing complex. In vitro experiments using a glutathione S-transferase AID fusion protein revealed significant cytidine deaminase activity that is blocked by tetrahydrouridine and by zinc chelation. However, AID alone did neither demonstrate activity in C to U editing of apoB mRNA nor bind to AU-rich RNA targets. AID mRNA expression is induced in splenic B cells that were activated in vitro or by immunizations with sheep red blood cells. In situ hybridization of immunized spleen sections revealed the restricted expression of AID mRNA in developing germinal centers in which modulation of immunoglobulin gene information through somatic hypermutation and class switch recombination takes place. Taken together, these findings suggest that AID is a new member of the RNA-editing deaminase family and may play a role in genetic events in the germinal center B cell.
Collapse
|
99
|
|
100
|
Sakiyama T, Ikuta K, Nisitani S, Takatsu K, Honjo T. Requirement of IL-5 for induction of autoimmune hemolytic anemia in anti-red blood cell autoantibody transgenic mice. Int Immunol 1999; 11:995-1000. [PMID: 10360974 DOI: 10.1093/intimm/11.6.995] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
IL-5, IL-10 and lipopolysaccharide (LPS) are known to activate B-1 cells in vivo in normal mice and anti-red blood cell autoantibody transgenic mice (HL mice). To assess the exact role of IL-5 in proliferation and activation of peritoneal B-1 cells, we analyzed IL-5 receptor alpha chain-deficient HL (IL-5Ralpha-/- x HL) mice generated by the cross between IL-5Ralpha-/- and HL mice. In IL-5Ralpha-/- x HL mice, Ig-producing B-1 cells in the peritoneal cavity were negligible, although the total number of B-1 cells in the peritoneal cavity were as many as 30% of that in HL mice. Moreover, LPS- or IL-10-induced differentiation of B-1 cells into antibody-producing cells was severely impaired in IL-5Ralpha-/- x HL mice. We also used in vivo 5-bromo-2'-deoxyuridine labeling to estimate the proliferation of B-1 cells in IL-5Ralpha-/- mice. The absence of IL-5Ralpha did not affect spontaneous proliferation of peritoneal B-1 cells. However, induced proliferation of peritoreal B-1 cells by oral administration of LPS was markedly impaired in IL-5Ralpha-/- mice. These results suggest that IL-5 is required for activation-associated proliferation of B-1 cells but not for their spontaneous proliferation and support the idea that IL-5 plays an important role on the induction of autoantibody production from B-1 cells.
Collapse
MESH Headings
- Anemia, Hemolytic, Autoimmune/genetics
- Anemia, Hemolytic, Autoimmune/immunology
- Animals
- Autoantibodies/genetics
- B-Lymphocytes/immunology
- B-Lymphocytes/metabolism
- Erythrocytes/immunology
- Interleukin-10/pharmacology
- Interleukin-5/immunology
- Interleukin-5/physiology
- Lipopolysaccharides/pharmacology
- Mice
- Mice, Knockout
- Mice, Transgenic
- Receptors, Interleukin/deficiency
- Receptors, Interleukin/genetics
- Receptors, Interleukin/physiology
- Receptors, Interleukin-5
Collapse
|