Publications by authors named "Sasazuki T"

With the use of polymerase chain reaction (PCR) and sequence-specific oligonucleotide probe (SSOP), we established a DNA typing method of the HLA-A locus. A pair of primers to amplify the highly polymorphic region of HLA-A gene including exon 2 and exon 3 was designed and the amplified DNAs were hybridized with 91 types of 32P labeled SSOPs. This method allowed discrimination of all known HLA-A alleles except for two combinations, A*0201 or A*0209 and A*0207 or A*0215N, which have identical sequences in exon 2 and exon 3.

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To analyze the immune response to the C region of group A streptococcal M protein in patients with rheumatic fever (RF), we cloned the structural gene for the C region of type 12 M protein and produced recombinant C region of M protein. IgG titers against the C region of M protein were measured by ELISA from sera of patients with RF (n = 10), uncomplicated streptococcal pharyngitis (n = 26), and age-matched controls (n = 49). IgG titers against the C region were significantly higher in patients with RF than in controls or patients with uncomplicated streptococcal pharyngitis (43 versus 1.

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Previous studies have indicated that certain alleles of HLA-DR and -DQ genes were strongly associated with susceptibility and resistance to insulin-dependent diabetes mellitus (IDDM), and the role of DQ molecule in IDDM has been suggested. To further clarify the association of DQ alleles with IDDM, we determined the nucleotide sequences of full-length cDNA from 13 DQA1 alleles and 14 DQB1 alleles. The sequencing analysis revealed sequence polymorphisms outside the hypervariable region of DQ genes.

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Previous studies have shown that a transgenic I-E alpha gene, the mouse homologue of human DR alpha gene, prevents the development of insulitis and hence of diabetes in NOD mice. To investigate the mechanism of this prevention, we generated two strains of NOD mice expressing DR alpha E beta molecule: DR alpha-24-NOD expressing DR alpha E beta molecule on thymic epithelial cells (TEC) and bone marrow-derived cells (BDC), and DR alpha-30-NOD expressing DR alpha E beta molecule only on the TEC, and these mice were monitored for disease development. Because the DR alpha E beta molecule reconstituted I-E controlled immune regulation, it would become clear which cell type, TEC or BDC, was responsible for the I-E-mediated disease protection.

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Investigation of pairs of unrelated persons mismatched for a particular HLA-DQB1 or -DPB1 gene on the induction of cytotoxic T lymphocytes (CTL) revealed that HLA-DQ and HLA-DP antigens provided a slight proliferative stimulus which was, however, sufficient for the generation of CTL. Monomorphic anti-DQ and anti-DP monoclonal antibodies abrogated the induction of cytotoxic response. The results indicate that the HLA-DQ and HLA-DP antigens play a similar role to HLA-DR specificities in clinical bone marrow transplantation.

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We investigated human leukocyte antigen (HLA) class I and class II antigens in 56 Japanese patients with subacute thyroiditis (SAT) who visited our out-patient clinic between 1988 and 1990. We found SAT to be associated with not only HLA-B35 (40 patients; P < 0.000001; relative risk, 18.

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To investigate how single amino acid substitutions in MHC class I molecules affect differences in peptide repertoires, we eluted and sequenced the naturally processed peptides from three HLA-A2 subtypes (HLA-A*0204, -A*0206, and -A*0207) that differ by a single amino acid residue substitution each with HLA-A*0201 at the floor of the binding groove. Allele-specific peptide motifs for each HLA-A2 subtype substantially differed from that of HLA-A*0201 in the dominant anchor residues. The relative signal intensities for 18 self peptides, determined by mass spectrometry, precisely reflected these peptide motifs.

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The growth of solid tumors in vivo beyond 1-2 mm in diameter requires induction and maintenance of an angiogenic response. This can occur through the release of various angiogenic growth factors from tumor cells. One such factor is vascular endothelial growth factor/vascular permeability factor (VEGF/VPF), a secreted and specific mitogen for vascular endothelial cells.

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HLA class II genes (DRB, DQA, DQB, DPA, and DPB) were typed at the DNA level using polymerase chain reaction/sequence-specific oligonucleotide probe analysis in 78 unrelated patients with DCM and 336 unrelated healthy controls to elucidate the HLA alleles or HLA haplotypes associated with DCM. The frequencies of DRB1*1401 (15.4% v 4.

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Early-onset pauciarticular juvenile chronic arthritis (EOPA-JCA) has associations with different alleles of the MHC region (HLA-A2, DR5, 6, 8, DQA1*0401, *0501, *0601 and DPB1*0201). All susceptible DQA1 alleles carry an exclusive sequence motif. MHC-class II gene expression is controlled by 5' flanking upstream regulatory regions (URR).

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Interaction of the HLA-DP9 (DPA1*0201/DPB1*0901) molecule and M protein of serotype 12 (SS95/12) streptococci, a main component of the streptococcal cell wall Ag, has been investigated to decipher peptide-binding capacity and T cell activation in the context of the HLA-DP molecule. Seven antigenic peptides (amino acids 19-25) restricted by the HLA-DP9 molecule were identified in M12 protein, using M12 protein- or peptide-specific T cell lines from naturally exposed individuals. The binding affinity of each peptide to the HLA-DP9 molecule was measured by fluorescence intensity of biotinylated peptides bound to L cell transfectants expressing HLA-DP9, followed by treatment with avidin-fluorescence.

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HLA-linked genetic factors involved in the pathogenesis of HT were studied in 71 patients with HT by serologic typing for HLA-A, -B, -C, -DR, and -DQ specificities and by DNA typing for HLA-DRB1, -DRB3, -DRB4, -DRB5, -DQA1, -DQB1, AND -DPB1 genes using the PCR-SSOP method. Typing results demonstrated significant positive associations of HT with HLA-A2 and -DRB4*0101 (DR53) (p < 0.01, RR = 2.

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Sixty-five living related kidney transplant pairs were analyzed for matching at HLA class II loci by the polymerase chain reaction (PCR)--sequence specific oligonucleotide probe (SSOP) method. The retrospective HLA matching study revealed that there were many early graft loss cases despite the DQB compatibility, contrary to our expectation. There were 54 DRB1 one-mismatched cases, in which 7 of the 11 (64%) DQB zero-mismatched cases had lost their grafts, while the graft loss cases were only 10 of the 43 (23%) DQB one-mismatched pairs (P value = 0.

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To reconstitute the human immune system in mice, transgenic mice expressing human CD4 and human major histocompatibility complex (MHC) class II (DQw6) molecules in an endogenous CD4- and CD8-deficient background (mCD4/8-/-), after homologous recombination, have been generated. We report that expression of human CD4 molecule in mCD4/8-/- mice rescues thymocyte development and completely restores the T cell compartment in peripheral lymphoid organs. Upon vesicular stomatitis virus (VSV) challenge, the reconstituted mature T cell population effectively provide T help to B cells in immunoglobulin class switching from IgM to specific IgG-neutralizing antibodies.

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An ovalbumin (OVA)-specific T cell line (TCL) was established from a patient with hen egg allergy. The TCL was CD4+, expressed alpha beta T cell receptor, and recognized OVA presented by HLA-DR10. Based on the response of the TCL to synthetic OVA peptides, it was found that the TCL recognized OVA 323-339, which is a major T cell epitope presented by murine I-Ad.

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Studies in vitro have suggested that a species barrier exists in functional interaction between human histocompatibility leukocyte antigen (HLA) class II and mouse CD4 molecules. However, whether mouse CD4+ T cells restricted by HLA class II molecules are generated in HLA class II transgenic mice and respond to peptide antigens across this barrier has remained unclear. In an analysis of T cell responses to synthetic peptides in mice transgenic for HLA-DR51 and -DQ6, we found that DR51 and DQ6 transgenic mice acquired significant T cell response to influenza hemagglutinin-derived peptide 307-319 (HA 307) and Streptococcus pyogenes M12 protein-derived peptide 347-397 (M6C2), respectively.

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In search for the pathogenetic factors, we have found the following: 1) Chronic bacterial foci in the upper airway is showing adverse effect on clinical course of sarcoidosis. Alpha-streptococcus is mainly detected. 2) The prevalence of chronic tonsillitis in sarcoidosis is high if compared with that among Japanese adults examined by rhinolaryngologists.

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The present study was undertaken to define the gene(s) of importance on the long arm of chromosome 18 (chromosome 18q) in endometrial carcinomas. We analyzed loss of heterozygosity (LOH) at 3 loci on chromosome 18q and DCC gene expression by the reverse-transcriptase/polymerase chain reaction (RT-PCR) method. Among 61 tumors that were informative, 16 (26%), estimated to be a minimum number, showed allelic losses at one or more chromosome 18q loci.

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We have examined for a mutation in the cardiac beta myosin heavy chain gene from Japanese patients with familial hypertrophic cardiomyopathy. A missense mutation due to a G to A transition in codon 935, leading to a replacement of Glu with Lys, was found in one patient. Family members of this patient were then examined.

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