Biomedical subjects

T Juji

Publications and source records attributed to T Juji.

At least 19 recordsLinked to original sources

PubMed1999

Crystal structure of the human p58 killer cell inhibitory receptor (KIR2DL3) specific for HLA-Cw3-related MHC class I.

BACKGROUND: T cells and natural killer (NK) cells perform complementary roles in the cellular immune system. T cells identify infected cells directly through recognition of antigenic peptides that are displayed at the target cell surface by the classical major histocompatibility complex (MHC) class I molecules. NK cells monitor the target cell surface for malfunction of this display system, lysing potentially infected cells that might otherwise evade recognition by the T cells. Human killer cell inhibitory receptors (KIRs) control this process by either inhibiting or activating the cytotoxic activity of NK cells via specific binding to MHC class I molecules on the target cell. RESULTS: We report the crystal structure of the extracellular region of the human p58 KIR (KIR2DL3), which is specific for the human MHC class I molecule HLA-Cw3 and related alleles. The structure shows the predicted topology of two tandem immunoglobulin-like domains, but comparison with the previously reported structure of the related receptor KIR2DL1 reveals an unexpected change of 23 degrees in the relative orientation of these domains. CONCLUSIONS: The altered orientation of the immunoglobulin-like domains maintains an unusually acute interdomain elbow angle, which therefore appears to be a distinctive feature of the KIRs. The putative MHC class I binding site is located on the outer surface of the elbow, spanning both domains. The unexpected observation that this binding site can be modulated by differences in the relative domain orientations has implications for the general mechanism of KIR-MHC class I complex formation.

Amino Acid Sequence↗

PubMed1999

Polymorphism in RANTES chemokine promoter affects HIV-1 disease progression.

RANTES (regulated on activation normal T cell expressed and secreted) is one of the natural ligands for the chemokine receptor CCR5 and potently suppresses in vitro replication of the R5 strains of HIV-1, which use CCR5 as a coreceptor. Previous studies showed that peripheral blood mononuclear cells or CD4(+) lymphocytes obtained from different individuals had wide variations in their ability to secrete RANTES. These findings prompted us to analyze the upstream noncoding region of the RANTES gene, which contains cis-acting elements involved in RANTES promoter activity, in 272 HIV-1-infected and 193 non-HIV-1-infected individuals in Japan. Our results showed that there were two polymorphic positions, one of which was associated with reduced CD4(+) lymphocyte depletion rates during untreated periods in HIV-1-infected individuals. This mutation, RANTES-28G, occurred at an allele frequency of approximately 17% in the non-HIV-1-infected Japanese population and exerted no influence on the incidence of HIV-1 infection. Functional analyses of RANTES promoter activity indicated that the RANTES-28G mutation increases transcription of the RANTES gene. Taken together, these data suggest that the RANTES-28G mutation increases RANTES expression in HIV-1-infected individuals and thus delays the progression of the HIV-1 disease.

Base Sequence↗

PubMed1999

Extracellular signal-regulated kinase, stress-activated protein kinase/c-Jun N-terminal kinase, and p38mapk are involved in IL-10-mediated selective repression of TNF-alpha-induced activation and maturation of human peripheral blood monocyte-derived dendritic cells.

TNF-alpha or IL-10 has been implicated to reversibly regulate physiological states of dendritic cells (DCs). However, little is known about dual stimulations of these cytokines on DC properties and the intracellular signaling events that are responsible for the regulation of these states. Here, we show that a family of mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase 2 (ERK2), stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), and p38mapk, are potentially involved in IL-10-mediated selective suppression of TNF-alpha-induced changes of the monocyte-derived DC properties. TNF-alpha induced the cluster formation of the cells and the enhancement of cell surface expression levels of CD83, CD86, and HLA-DR, and T cell stimulatory capacity, whereas the capacities for the endocytosis and the chemotactic migration were suppressed in these cells. Treatment of monocyte-derived DCs with IL-10 resulted in the reduction of the cell surface expression levels of CD86, HLA-DR, and T cell stimulatory capacity, whereas both endocytic and chemotactic migratory capacities were increased by IL-10. Dual stimulations of monocyte-derived DCs with TNF-alpha and IL-10 selectively antagonized their respective effects on these DC properties. TNF-alpha induced tyrosine phosphorylation and enzymatic activation of ERK2, SAPK/JNK, and p38mapk, whereas IL-10 did not induce these events. Dual stimulations of TNF-alpha plus IL-10 abolished TNF-alpha-induced changes of these MAPKs in DCs. These results suggest that the blockage in the MAPKs cascades contributes to IL-10-mediated repression of TNF-alpha-induced changes of DC properties.

Calcium-Calmodulin-Dependent Protein Kinases↗

PubMed1999

CC chemokine receptors, CCR-1 and CCR-3, are potentially involved in antigen-presenting cell function of human peripheral blood monocyte-derived dendritic cells.

We examined the potential involvement of two CC chemokine receptors (CCRs), CCR-1 and CCR-3, in the functional activation of granulocyte-macrophage colony-stimulating factor (GM-CSF) plus interleukin-4 (IL-4)-generated human peripheral blood monocyte-derived immature dendritic cells (DCs). Flow cytometric analysis showed that CCR-1, CCR-3, CCR-5, and CXC chemokine receptor (CXCR)-4 were expressed on the cell surface of monocyte-derived DCs. Treatment with a monoclonal antibody (MoAb) to either CCR-1 or CCR-3 but not MoAbs to CCR-5 and CXCR-4 abolished chemotactic migration of monocyte-derived DCs. The DCs treated with either the anti-CCR-1 MoAb or anti-CCR-3 MoAb were less efficient than untreated DCs in proliferation of allogeneic T cells (TCs) and TC-derived secretion of interferon-gamma (IFN-gamma). The homotypic aggregation of DCs and heterotypic aggregation of DCs with TCs were suppressed by the anti-CCR-1 MoAb or anti-CCR-3 MoAb. These results indicate that CCR-1 and CCR-3 specifically regulate interaction of TCs and DCs in the process of antigen presentation.

Antibodies, Monoclonal↗

PubMed1999

Seroprevalence of human herpesvirus 8 in human immunodeficiency virus 1-positive and human immunodeficiency virus 1-negative populations in Japan.

To determine the seroprevalence of human herpesvirus 8 (HHV8) among human immunodeficiency virus 1 (HIV-1)-positive (HIV-1+) and HIV-1-negative (HIV-1-) populations in Japan, 276 HIV-1+ patients and 1,000 HIV-1- blood donors were enrolled in this study. Antibodies against HHV8 latency-associated nuclear antigen (LANA) were examined through indirect immunofluorescent assay by using a B-cell line that was infected latently with HHV8 (body cavity-based lymphoma 1). An HHV8- and Epstein-Barr virus-negative B-cell line (Ramos) was used as a control. Thirty-two seropositive cases against LANA (anti-LANA+) were identified among the 276 HIV-1+ patients who were studied. Five cases were foreigners living in Japan. The risk factor of all 27 Japanese cases was unprotected sexual intercourse, and the great majority of these cases (23 in 27; 85%) reported homosexual/bisexual behavior. Anti-LANA+ status correlated with the presence of sexually transmitted diseases, such as amoeba and HBV infection, further suggesting male homosexual behavior as the main route of HHV8 transmission in Japan. Only two LANA+ cases were identified among 1,000 HIV- blood donors in Japan; thus, seroprevalence of HHV8 identified by LANA was estimated to be 0.2% among HIV-1- populations in this country.

Adolescent↗

PubMed1999

Tolerance of NK and LAK activity for HLA class I-deficient targets in a TAP1-deficient patient (bare lymphocyte syndrome type I).

NK cells recognize target cells that lack HLA class I molecules and lyse them, according to the 'missing self' hypothesis. It was previously reported that a TAP2-deficient patient with an HLA class I-deficiency, had a normal number of NK cells but that the lymphocytes of this patient had lost their NK activity against K562 cells. In this study, we investigated the HLA class I-recognizing NK receptor expressions and the NK and LAK activities of the lymphocytes of a TAP1-deficient patient. The patient had a normal number of NK cells. Although the lymphocytes showed LAK activity against class I expressing targets following IL-2, IL-12 and IL-15 stimulation for 3 days, neither NK nor LAK activity against targets lacking class I molecules was induced. The NK cells of the patient expressed class I-recognizing NK receptors, although the percentages of such cells were low. However, no differences were observed in the expression levels of inhibitory and activating NK receptors between lymphocytes of the patient and those of healthy controls, suggesting that the modulation of the NK receptor expression is not primarily responsible for this tolerance. These results also suggest that the lymphocytes of the patient are defective in the recognition of class I-deficient target cells in order to promote the induction of self tolerance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1999

Activation of human Valpha24NKT cells by alpha-glycosylceramide in a CD1d-restricted and Valpha24TCR-mediated manner.

Vact14NK(natural killer) T cells play an important role in controlling tumors or in preventing autoimmunity in the murine system. Valpha24NKT cells, the human counterpart of Valpha14NKT cells, may contribute to controlling the progression of autoimmune diseases in humans. These findings show the possibility that ligand(s) for these NKT cells can control the above-mentioned pathological conditions. Specific glycolipids such as alpha-galactosylceramide (alpha-GalCer) and alpha-glucosylceramide (alpha-GlcCer) have been identified as ligand(s) recognized by murine Valpha14NKT cells in a CD1d-restricted manner, but it remains unclear whether these glycolipids are ligand(s) for Valpha24NKT cells in humans. To determine whether alpha-glycosylceramide is presented by CD1d molecules in humans, we initially established a Valpha24NKT cell line specific for alpha-glycosylceramide using dendritic cell (DC) like cells from normal peripheral blood mononuclear cells (PBMC) in an autologous mixed leukocyte reaction (auto-MLR) system, and characterized the Valpha24NKT cell line. The Valpha24NKT cells were CD3+ CD4-CD8-Valpha24+Vbeta11+NKRP1A+ and specifically proliferated in response to alpha-glycosylceramide in CD1d-restricted and Valpha24TCR-mediated manner. The phenotypic and functional similarities between murine Valpha14NKT cells and human Valpha24NKT cells suggest that Valpha24NKT cells may play an important role in controlling tumors or in preventing autoimmunity as observed with Valpha14NKT cells.

Antigens, CD1↗

PubMed1999

Interleukin-13 is involved in functional maturation of human peripheral blood monocyte-derived dendritic cells.

Dendritic cells (DCs) are professional antigen presenting cells (APCs) that are required for the initiation of the immune response. DCs have been shown to be generated from hematopoietic stem cells, but relatively little is known about the regulation underlying differentiation and activation of DCs. Here, we report that recombinant human (rh)IL-13 induces functional maturation of rhGM-CSF plus rhIL-4 generated monocyte-derived immature DCs. Incubation of these immature DCs with rhIL-13 or rhTNF-alpha for 2 days resulted in increased surface expression of CD1a, CD11c, CD86 and HLA-DR. The DCs treated with rhIL-13 or rhTNF-alpha, but not rhIL-4, for 2 days were more efficient than unstimulated DCs in the primary autologous/allogeneic T-cell response whereas the antigen (Ag)-specific T-cell response was suppressed. The treatment of DCs with rhIL-13 as well as rhTNF-alpha for 4 days down-modulated endocytic capacity for FITC-dextran (FITC-DX) and lucifer yellow (LY), and induced surface expression of CD83. Morphological, phenotypical, and functional analyses revealed that the monocytes cultured with rhGM-CSF plus rhIL-13 gave rise to a DC type more mature than rhGM-CSF plus rhIL-4-induced DCs. These findings revealed a new role for rhIL-13 in regulating both the maturation and activation of DCs.

Antigen Presentation↗

PubMed1999

Cell surface expression of HLA-E molecules on PBMC from a TAP1-deficient patient.

It was recently revealed from studies on TAP-deficient cell lines that HLA-E molecules are associated with nonamer peptides derived from certain HLA class I leader sequences and are expressed on the cell surface in a TAP-dependent manner. We have previously reported a homozygous TAP1 gene mutation in a HLA class I-deficient patient. In the present report, we demonstrate HLA-E molecule expression on the surface of the peripheral blood mononuclear cells (PBMC) of the TAP1-deficient patient. The HLA-E expression level on the monocytes of the patient was as high as that in healthy donors, whereas the HLA-E expression level on the lymphocytes of the patient was slightly lower. On the other hand, HLA-E expression was not detected on KMW-B2 cells, an Epstein-Barr virus (EBV)-transformed B-cell line derived from the lymphocytes of the TAP1-deficient patient. These data suggest the existence of TAP-dependent and -independent pathways for the surface expression of HLA-E molecules.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1999

Analysis of human leukocyte antigen-G polymorphism including intron 4 in Japanese couples with habitual abortion.

PROBLEM: The purpose of this study was to clarify whether there is a difference between the allele frequency of human leukocyte antigen (HLA)-G in healthy Japanese people and that of Japanese couples with habitual abortion. METHOD OF STUDY: Exons 2, 3, 4, and intron 4 of the HLA-G gene were analyzed in 20 couples with habitual abortion, using polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis. Intron 4 of the HLA-G gene was also analyzed in 54 healthy individuals. The nucleotide sequence of the PCR product of intron 4 was further determined by direct sequencing. RESULTS: Two kinds of nucleotide sequence were identified in intron 4 of the HLA-G gene, one of which was identical to that of HLA-G*01011, and the other was identical to that of HLA-G*01012, G*01013, and G*0104. The frequency of each allele in affected women and their husbands did not significantly differ from that of healthy individuals, and no mutation was found in any affected couple. CONCLUSION: HLA-G allelic abnormality seemed to have little, if any, implication in the pathogenesis of habitual abortion.

Abortion, Habitual↗

PubMed1999

Splice acceptor site mutation of the transporter associated with antigen processing-1 gene in human bare lymphocyte syndrome.

Expression of histocompatibility leukocyte antigen (HLA) class I molecules on the cell surface depends on the heterodimer of the transporter associated with antigen processing 1 and 2 (TAP1 and TAP2), which transport peptides cleaved by proteasome to the class I molecules. Defects in the TAP2 protein have been reported in two families with HLA class I deficiency, the so-called bare lymphocyte syndrome (BLS) type I. We have, to our knowledge, identified for the first time a splice site mutation in the TAP1 gene of another BLS patient. In addition, class I heavy chains (HCs) did not form the normal complex with tapasin in the endoplasmic reticulum (ER) of the cells of our patient.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1998

Effect of matching of class I HLA alleles on clinical outcome after transplantation of hematopoietic stem cells from an unrelated donor. Japan Marrow Donor Program.

BACKGROUND: The requirements with respect to HLA compatibility and the relative importance of matching for individual class I and class II HLA alleles in the transplantation of hematopoietic stem cells from unrelated donors have not yet been established. METHODS: We performed retrospective DNA typing of alleles at 11 polymorphic loci of HLA genes in 440 recipients of hematopoietic stem cells from unrelated donors who were serologically identical with their respective recipients for HLA-A, B, and DR antigens. Of these recipients, 80 percent had leukemia; the rest had lymphoma, marrow failure, or a congenital disorder. RESULTS: Multivariate analysis showed that incompatibility for HLA-A alleles and incompatibility for HLA-C alleles were independent risk factors for severe acute graft-versus-host disease (GVHD) (HLA-A, P=0.006; HLA-C, P=0.001). Mismatching of HLA-A, but not of HLA-C, alleles was an independent risk factor for death (P<0.001). Matching [corrected] of HLA-C alleles was a significant risk factor for relapse of leukemia (P=0.035). HLA-B disparity was a significant risk factor for both GVHD and death in the univariate analysis, but not in multivariate analysis. Disparities in class II HLA alleles of the DRB1, DQA1, DQB1, DPA1, and DPB1 loci were not identified as significant risk factors for acute GVHD or death in the multivariate analysis. CONCLUSIONS: Genomic typing of class I HLA alleles adds substantially to the success of transplantation of hematopoietic stem cells from unrelated donors, even if the donors are serologically identical to their recipients with respect to HLA-A, B, and DR antigens.

Adolescent↗

PubMed1998

Highly efficient recovery of functional single-chain Fv fragments from inclusion bodies overexpressed in Escherichia coli by controlled introduction of oxidizing reagent--application to a human single-chain Fv fragment.

An improved and efficient refolding system for a single-chain antibody fragment (scFv) from inclusion bodies expressed in Escherichia coli was developed. Stepwise removal of denaturing reagent and controlled addition of oxidizing reagent were found to be the most effective conditions to achieve for almost complete recovery of functional monomeric scFv from inclusion bodies. Adding L-arginine to the refolding solution also increased the yield of refolded functional scFv. The single-chain Fv fragments of both a mouse anti-lysozyme monoclonal antibody, HyHEL10, and a human monoclonal antibody against the D antigen of the Rh blood group, D10, in solubilized inclusion bodies could be refolded under these conditions with yields of up to 95%. The refolding procedures developed in this study will contribute to providing a stable supply of large amounts of human single-chain Fv fragments.

Animals↗

PubMed1998

Evidence that CD31, CD49b, and CD62L are immunodominant minor histocompatibility antigens in HLA identical sibling bone marrow transplants.

Despite complete matching of siblings for the HLA loci, after bone marrow transplantation (BMT), approximately 20% develop graft-versus-host disease (GVHD). This is presumably due to incompatibility of minor histocompatibility antigens (mHa). We investigated the polymorphisms of 14 adhesion molecules (CD2, CD28, CD31, CD34, CD36, CD42, CD44, CD48, CD49b, CD54, CD62L, CD86, CD102, and CD106) in Japanese subjects and their association with the occurrence of GVHD after allogeneic HLA identical BMT. Six molecules (CD2, CD31, CD42, CD49b, CD54, and CD62L), which were found to be polymorphic, were then examined in 118 HLA identical sibling donors and recipients who had undergone BMT. Association of the incompatibility of the polymorphic molecules with the presence or absence of GVHD was examined. In these six, we observed a significant correlation between acute GVHD and the compatibility of CD31 (codons 563/670) (Pcorrected = .018), and CD31 (codons 563/670) + CD62L (Pcorrected = .018) in patients with the HLA-B44-like superfamily. In patients with the HLA-A3-like superfamily, the compatibility of CD62L (Pcorrected = .03) and CD62L + CD49b (P = . 004, Pcorrected = .078) was associated with acute GVHD. Therefore, CD31, CD49b, and CD62L might be candidates for immunodominant mHa.

Adolescent↗

PubMed1998

Guillain-Barré and Fisher's syndromes subsequent to Campylobacter jejuni enteritis are associated with HLA-B54 and Cw1 independent of anti-ganglioside antibodies.

The frequencies of human leukocyte antigens (HLA)-class I (A, B and Cw) were determined serologically and those of HLA-class II (DRB1 and DQB1) at the genomic level in 35 Japanese patients with Guillain-Barré syndrome (GBS), 58 with Fisher's syndrome (FS), and 112 healthy controls. HLA-B54 and -Cw1 antigens were found in GBS and FS patients from whom Campylobacter jejuni had been isolated more often than found in the healthy controls. No HLA types were related to GBS or FS as a whole, except for the B54 antigen which often was significant in the entire GBS group. This relation, however, may depend on the high population of C. jejuni-isolate patients in our GBS group. There were no relationships between the frequencies of HLA types and the presence of serum IgG antibodies to GM1, GQ1b, GD1a, or GalNAc-GD1a. Our findings suggest that HLA types are associated with the onset of GBS and FS after C. jejuni enteritis and that the HLA types in distinct GBS and FS subgroups of a single etiological origin need to be examined.

Antibodies↗

PubMed1998

Crystallization and preliminary diffraction studies of the extracellular region of human p58 killer cell inhibitory receptor (KIR2).

Molecules of the human killer cell inhibitory receptor (KIR) family, which belong to the immunoglobulin superfamily (IgSF), are expressed on the surface of natural killer (NK) cells and some subsets of T cells. These receptors function to mediate the inhibition or activation of cytotoxic activity by recognizing HLA class I molecules on the target cell. The extracellular region of a p58 KIR specific for HLA-Cw1,3,7 (KIR2) has been overproduced in Escherichia coli and purified. The recombinant KIR2 has been crystallized in 9-10% poly(ethylene glycol) methyl ether (average Mr = 8000), 50mM HEPES, 8% ethylene glycol, 0.5% octyl-beta-glucoside, pH 7.5, at 294 K using the sitting-drop vapour-diffusion method. Preliminary X-ray diffraction studies reveal the space group to be hexagonal (P6122 or P6522) with lattice constants a = b = 95.3, c = 130.8 A. A native data set (3 A resolution) has been collected at the Photon Factory (lambda = 1.0 A).

Crystallization↗

PubMed1998

Dendritic cells stimulate the expansion of bcr-abl specific CD8+ T cells with cytotoxic activity against leukemic cells from patients with chronic myeloid leukemia.

The role of T lymphocytes in the control of chronic myeloid leukemia (CML) after bone marrow transplantations has been clearly shown. This effect closely correlates with graft-versus-host disease (GVHD). A specific graft-versus-leukemia (GVL) effect separate from GVHD has been postulated but has been difficult to show. One possible target for specific GVL activity is the bcr-abl fusion protein characteristic of CML. We have investigated the use of normal peptide-pulsed dendritic cells for the generation of cytotoxic, bcr-abl-specific T cells from normal donors. T cells (CD3+, CD8+, TCR alpha beta+, and NK receptor-negative) generated from a normal donor (HLA A24, B52, B59, Cw1) after stimulation with autologous dendritic cells, primed with a 16 mer peptide spanning the b3a2 breakpoint of bcr-abl, lysed CML cells from the peripheral blood of seven patients with CML with the b3a2 breakpoint. CML cells from four patients with only the b2a2 breakpoint were not lysed. Phytohemagglutinin (PHA) blasts derived from peripheral blood of patients with CML were not lysed, suggesting that cytotoxicity was not due to alloreactivity. Blocking experiments with anti-HLA-A,B,C indicated that cytotoxicity was dependent on recognition of major histocompatibility complex (MHC) class I molecules, although cytotoxicity was not MHC-restricted because not all patients shared HLA types with the T-cell donor. Specificity for bcr-abl and absence of alloreactivity was confirmed by the presence of lytic activity against autologous and allogeneic class I HLA-A matched monocytes pulsed with the 16 mer bcr-abl fusion peptide, but not against unpulsed monocytes or monocytes pulsed with other peptides. These results show that bcr-abl-specific T cells with marked cytotoxic activity against CML cells can be generated and amplified from normal donor peripheral blood. Recognition of HLA molecules is essential for cytotoxicity but strict HLA identity is not required.

Antigens↗

PubMed1998

Molecular cloning and characterization of decay-accelerating factor deficiency in Cromer blood group Inab phenotype.

An additional decay-accelerating factor (DAF) mutation, designated as Inab phenotype in the Cromer blood group system, was recently identified in a 28-year-old Japanese woman (H.A.). The red blood cells of H.A., like those of other Inab phenotype individuals, were negative for Cromer system antigens, Cra, Tca, Dra, UMC, and IFC. The deficiency of DAF on the red blood cells of H.A. has been shown by immunoblotting with a murine monoclonal antibody to DAF. Molecular analysis has shown that H.A. is homozygous for a single nucleotide substitution, C1579-->A, at the position 24 bp upstream of the 3'-end of exon 2 of the DAF gene. This substitution causes the activation of a novel cryptic splice site and results in the production of mRNA with a 26 bp deletion. The deletion introduces a reading frame shift and creates a stop codon immediately downstream of the deletion. Translation of mRNA would be terminated at the first amino acid residue of the second short consensus repeat (SCR2) domain (exon 3) of DAF. The functional domains of DAF's complement regulatory activity and the carboxy-terminal signal domains for glycosylphosphatidylinositol (GPI) anchoring are predicted to be lacking in H.A. Thus, there would be no DAF present on the cell surface.

Adult↗