Direct observation of a Ti/Cu interface with atomic displacement under electron irradiation.

Unlabelled: A Ti film was deposited onto a Cu substrate by means of a radio frequency magnetron sputtering

Method: Cross-sectional thin foils for TEM observation were prepared using a focused ion beam. Electron irradiation was carried out using a high-resolution high-voltage electron microscope operated at 1.25 MV.

Histological diversity of vasculitic lesions in MPO-ANCA-positive autopsy cases.

To investigate the variety of histological features of vasculitic lesions in myeloperoxidase-specific antineutrophil cytoplasmic antibody (pANCA)-related vasculitis, retrospective pathological analysis was done on 13 autopsy cases, collected from 1990 to 1998 at five hospitals. These cases were classified into three groups: (i) pulmonary-renal syndrome characterized by capillaritis of lung and glomeruli with occasional small-vessel arteritis and/or phlebitis; (ii) glomerular capillaritis without pulmonary involvement associated with significant small-vessel arteritis; and (iii) extensive distribution of small-vessel arteritis with no capillary involvement. The results suggest that pANCA-related vasculitis encompasses a wide variety of vasculitic syndromes, including pulmonary-renal syndrome, microscopic polyarteritis nodosa, and classic polyarteritis nodosa.

IL-1 enhances T cell-dependent antibody production through induction of CD40 ligand and OX40 on T cells.

IL-1 is a proinflammatory cytokine that plays pleiotropic roles in host defense mechanisms. We investigated the role of IL-1 in the humoral immune response using gene-targeted mice. Ab production against SRBC was significantly reduced in IL-1alpha/beta-deficient (IL-1(-/-)) mice and enhanced in IL-1R antagonist(-/-) mice.

Role of genetic factors in organ-specific autoimmune diseases induced by manipulating the thymus or T cells, and not self-antigens.

There are accumulating demonstrations that manipulation of the T-cell immune system, such as elimination of a particular T-cell subpopulation from the periphery or removal of the thymus during a critical neonatal period, can elicit activation/expansion of pathogenic self-reactive T cells from the remaining T cells and produce a wide spectrum of organ-specific autoimmune diseases in otherwise normal mice or rats. The genetic makeup of the hosts appears to play a key role in determining which self-reactive T-cell clones are prone to be activated under such circumstances, since a comparable degree of the immunologic abnormality elicits autoimmune disease in different spectrums of organs, with different incidences and severities, depending on the mouse or rat strains used. These findings indicate that one aspect of natural immunologic self-tolerance is maintained by a T cell-mediated control of potentially pathogenic self-reactive T cells in the periphery, and that defective control, caused by environmental insults or genetic abnormalities, suffices to cause autoimmune disease; furthermore, in the presence of such a T-cell abnormality, host genetic factors including MHC and non-MHC genes may determine the specificity and intensity of the autoimmune responses, and consequently the phenotype of the autoimmune disease.

Localization of recombination activating gene 1/green fluorescent protein (RAG1/GFP) expression in secondary lymphoid organs after immunization with T-dependent antigens in rag1/gfp knockin mice.

Secondary rearrangements of immunoglobulin gene segments that generate a new antibody repertoire in peripheral B cells have been described as receptor revision and occur by as yet unknown mechanisms. To determine the importance of recombination activating gene (RAG) expression in receptor revision, heterozygous rag1/green fluorescent protein (gfp) knockin mice were used to examine the location of RAG1 expression in the germinal centers (GCs) of lymphoid follicles after immunization with a variety of T-cell-dependent antigens. Immunization of rag1/gfp heterozygous mice or rag1 homozygous knockout mice reconstituted with rag1/gfp heterozygous spleen cells caused the down-regulation of RAG1/GFP signal in GCs.

CD40 expression is induced by the introduction of IgM receptor on the surface of pro-B cell line NFS70.

To examine the molecular mechanism of B cell differentiation, we introduced rearranged immunoglobulin (Ig) mu- and kappa-chain genes into the NFS70 pro-B cell line and observed their maturation. The IgR(+)-transfectants had characteristics of mature surface IgM (sIgM)+ B220high CD40+ CD38+ CD25+ B cells. CD40 expression levels were regulated by stimulation via the IgR.

A rat model of hypereosinophilic syndrome.

Hypereosinophilia-occurring rats without chemical and antigen treatment have been maintained in our laboratory. The rat, Matsumoto Eosinophilia Shinshu (mes), showed hypereosinophilia at the age of 9 weeks or older and developed eosinophil-related inflammatory lesions in many organs. These lesions included: aortitis, granulomatous lesion in the mesenteric lymph node, inflammatory fibroid polyp of the stomach and pulmonary vasculitis with septal infiltration.

Increased T cell autoreactivity in the absence of CD40-CD40 ligand interactions: a role of CD40 in regulatory T cell development.

Mutations in the CD40 ligand (CD40L) gene lead to X-linked immunodeficiency with hyper-IgM, which is often associated with autoimmune diseases. To determine the contribution of defective CD40-CD40L interactions to T cell autoreactivity, we reconstituted CD40-CD40L interactions by transferring T cells from CD40-deficient mice to syngenic athymic nude mice and assessed autoimmunity. T cells from CD40-deficient mice triggered autoimmune diseases accompanied with elevations of various autoantibodies, while those from wild-type mice did not.

Role of reactive oxygen species in gallic acid-induced apoptosis.

We earlier demonstrated that gallic acid (3,4,5-trihydroxybenzoic acid) induced apoptosis in promyelocytic leukemia HL-60RG cells, which was inhibited by catalase and intracellular Ca2+ chelator. In this study, we further studied the involvement of reactive oxygen species (ROS) and intracellular Ca2+ in gallic acid-induced apoptosis. The enhancement of intracellular ROS in HL-60RG cells was detected dose-dependently as early as 5 min after stimulation with gallic acid by using 5,6-carboxy-2',7'-dichlorofluorescin diacetate (DCFH-DA).

Structure, expression, and chromosomal localization of the human gene encoding a germinal center-associated nuclear protein (GANP) that associates with MCM3 involved in the initiation of DNA replication.

A 210kDa protein named GANP is upregulated in germinal center (GC)-B cells in the spleen of antigen-immunized mouse. We studied a human ganp gene (hganp) encoding a putative polypeptide of 1980 amino acids. The carboxyl-terminal 721-amino-acid sequence of hGANP is identical to Map80, that is presumably generated by alternative splicing of hganp/Map80 gene.

Immunologic self-tolerance maintained by CD25(+)CD4(+) regulatory T cells constitutively expressing cytotoxic T lymphocyte-associated antigen 4.

This report shows that cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) plays a key role in T cell-mediated dominant immunologic self-tolerance. In vivo blockade of CTLA-4 for a limited period in normal mice leads to spontaneous development of chronic organ-specific autoimmune diseases, which are immunopathologically similar to human counterparts. In normal naive mice, CTLA-4 is constitutively expressed on CD25(+)CD4(+) T cells, which constitute 5-10% of peripheral CD4(+) T cells.

Recurrent idiopathic iridocyclitis after autologous peripheral blood stem-cell transplantation followed by G-CSF administration for acute lymphoblastic leukemia.

We describe a patient who experienced a recurrence of idiopathic iridocyclitis on day 12 after autologous peripheral blood stem-cell transplantation (auto-PBSCT) followed by G-CSF administration for acute lymphoblastic leukemia (ALL). Autologous SCT has been reported to be effective and safe in achieving dose intensification of chemotherapeutic drugs for the treatment of hematopoietic malignancies, but its therapeutic effect on autoimmune diseases is not definite. The findings from the present case suggest that auto-PBSCT followed by G-CSF administration for patients with a history of some kind of autoimmune disorders may induce exacerbation or recurrence of its symptoms after hematopoietic recovery.

LDL receptor-related protein as a component of the midkine receptor.

Midkine (MK) is a heparin-binding growth factor with migration-promoting and survival-promoting activities. To identify signaling receptor(s) of MK, membrane glycoproteins with MK-binding activity were isolated from day 13 mouse embryos by lectin- and MK-affinity chromatography. SDS-PAGE followed by protein sequence analysis revealed the presence of LDL receptor-related protein (LRP) and NCAM in the fraction.

A novel nuclear phosphoprotein, GANP, is up-regulated in centrocytes of the germinal center and associated with MCM3, a protein essential for DNA replication.

Antigen (Ag) immunization induces formation of the germinal center (GC), with large, rapidly proliferating centroblasts in the dark zone, and small, nondividing centrocytes in the light zone. We identified a novel nuclear protein, GANP, that is up-regulated in centrocytes. We found that GANP was up-regulated in GC B cells of Peyer's patches in normal mice and in spleens from Ag-immunized mice.

Cutting edge: absence of expression of RAG1 in peritoneal B-1 cells detected by knocking into RAG1 locus with green fluorescent protein gene.

It has been proposed that Ig gene rearrangement in the peritoneal cavity (Pc) B-1 cells might be involved in autoantibody generation. To study possible secondary B cell maturation, we prepared mice carrying a target integration of gfp gene into a rag1 locus (rag1/gfp mice). The GFP+ cells express rag1 mRNA and are undergoing Ig gene rearrangement.

Effect of streptozotocin-induced diabetes mellitus on type 1 deiodinase (D1) in inherited D1-deficient mice.

We investigated the effects of streptozotocin (STZ)-induced diabetes on thyroid hormone levels, type 1 deiodinase (D1) activity and messenger RNA (mRNA) levels in inherited D1 deficient C3H mice in a comparative manner with control C57 mice. The apparent maximum velocity (Vmax) D1 values in C3H mice were 3% (liver) and 26% (kidney) of those in C57 mice. In C3H mice, similar serum T3, slightly higher T4, and 2.

Activity and substrate specificity of the murine STK2 Serine/Threonine kinase that is structurally related to the mitotic regulator protein NIMA of Aspergillus nidulans.

We isolated a murine STK2 (mSTK2) cDNA that is homologous to murine Nek1 serine/threonine kinase, a family member related to the cell cycle regulator kinase NIMA of Aspergillus nidulans. Structural comparison demonstrated that the kinase domain of mSTK2 is highly similar to NIMA/Nek family but the C-terminal region is not similar to any proteins except for human STK2 (hSTK2). Similarly to Nek1, mSTK2 is expressed ubiquitously among various organs and is upregulated in the testis.

A new member of the alpha4-related molecule (alpha4-b) that binds to the protein phosphatase 2A is expressed selectively in the brain and testis.

A murine alpha4, identified in lymphocytes, binds to protein phosphatase 2A (PP2A). We found another murine alpha4-related gene (named alpha4-b) expressed selectively in the brain and testis. The alpha4-b transcript is expressed in the brain and testis, but is not detected in the spleen, thymus, bone marrow, liver, kidney, lung, heart or muscle.

Effect of nicotine on type 2 deiodinase activity in cultured rat glial cells.

Intracellular generation of triiodothyronine (T3) from thyroxine (T4) by type 2 deiodinase (D2) in the mammalian brain, plays a key role in thyroid hormone action. The presence of D2 in rat astrocytes suggests the importance of glial cells in the regulation of intracellular T3 levels in the rat central nervous system (CNS). To analyze further the factors that regulate D2 activity in the CNS, we investigated the effects of nicotine and of mecamylamine, which inhibits the binding of nicotine with nicotinic acetylcholine receptors, on D2 activity in cultured mixed glial cells of the rat brain.

Involvement of a rapamycin-sensitive pathway in CD40-mediated activation of murine B cells in vitro.

Activation of resting B cells requires an initial triggering of the B cell antigen receptor (BCR) and secondary stimuli through various cytokine receptors and B cell activation molecules including CD40. We found that activation of B cells through CD40 is selectively inhibited by an immunosuppressant drug, rapamycin. This effect of rapamycin on anti-CD40-mediated activation of B cells was observed using three different in vitro assays.

Cell death-inducing activity by gallic acid derivatives.

In this study, the cytotoxic activity of gallic acid derivatives (GDs) was studied using some cancer cell lines. Among them, 3,4-methylenedioxyphenyl 3,4,5-trihydroxybenzoate (GD-1) and S-(3,4-methylenedioxyphenyl)-3,4,5-trihydroxy-thiobenzoate (GD-3) were found to induce cell death in cancer cell lines with IC50s ranging from 2.9 to 114.

Intravascular fasciitis of the forearm vein: a case report with immunohistochemical characterization.

Intravascular fasciitis is a very unusual variant of nodular fasciitis. A unique case of this lesion occurring in the proximal portion of the superficial vein of the forearm in an otherwise healthy 26-year-old man is reported. The intravascular polypoid lesion grew longitudinally along the vascular lumen, was loosely attached to the intimal layer, and was partly anchored beyond the internal elastic lamina into the medial smooth muscle layer.

Thymus and autoimmunity: production of CD25+CD4+ naturally anergic and suppressive T cells as a key function of the thymus in maintaining immunologic self-tolerance.

This study shows that the normal thymus produces immunoregulatory CD25+4+8- thymocytes capable of controlling self-reactive T cells. Transfer of thymocyte suspensions depleted of CD25+4+8- thymocytes, which constitute approximately 5% of steroid-resistant mature CD4+8- thymocytes in normal naive mice, produces various autoimmune diseases in syngeneic athymic nude mice. These CD25+4+8- thymocytes are nonproliferative (anergic) to TCR stimulation in vitro, but potently suppress the proliferation of other CD4+8- or CD4-8+ thymocytes; breakage of their anergic state in vitro by high doses of IL-2 or anti-CD28 Ab simultaneously abrogates their suppressive activity; and transfer of such suppression-abrogated thymocyte suspensions produces autoimmune disease in nude mice.

Virus and autoimmunity: induction of autoimmune disease in mice by mouse T lymphotropic virus (MTLV) destroying CD4+ T cells.

Neonatal infection of the mouse T lymphotropic virus (MTLV), a member of herpes viridae, causes various organ-specific autoimmune diseases, such as autoimmune gastritis, in selected strains of normal mice. The infection selectively depletes CD4+ T cells in the thymus and periphery for 2-3 wk from 1 wk after infection. Thymectomy 3 wk after neonatal MTLV infection enhances the autoimmune responses and produces autoimmune diseases at higher incidences and in a wider spectrum of organs than MTLV infection alone.