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Biomedical subjects

H Inoko

Publications and source records attributed to H Inoko.

At least 325 records · Page 18Linked to original sources
PubMed1987

The role of transfected HLA-DQ genes in the mixed lymphocyte reaction-like condition.

DR gene products are commonly thought to be involved in the induction of the mixed lymphocyte reaction (MLR). However, very little is known about the role of HLA-DQ antigens in the MLR. To address this question, we introduced DQ alpha and beta chain genes into mouse L cells, a human T-cell line, and a human premonocytoid cell line using a liposome-mediated transfer technique. The DQ alpha and DQ beta genomic clones were isolated from a DR2 DQw1 and a DR3 DQw2 phage library, respectively. The pSV2-Neo gene was introduced as a selection marker with both DQ alpha and DQ beta. The resultant transfected cells were able to bind several HLA class II monoclonal antibodies. In addition, these cells were found to be efficient in stimulating peripheral blood lymphocyte proliferation under MLR-like conditions, implying a role for HLA-DQ molecules in HLA-D typing differences.

Animals↗
PubMed1987

Expression and function of class II antigens on gastric carcinoma cells and gastric epithelia: differential expression of DR, DQ, and DP antigens.

The expression of human histocompatibility leukocyte antigen class II antigens on gastric epithelia and gastric carcinoma (GaCa) was studied with the use of murine monoclonal antibodies to DR, DQ, and DP antigens. DR and DP antigens but not DQ antigens were demonstrated in fundic glands of normal gastric epithelia, and DP+ cells were located in part of the DR+ epithelia. Of 15 GaCas examined, 11 expressed DR antigen, and the degree of the expression varied considerably among the specimens. DP antigen was found in 3 of the 11 DR+ carcinomas, and the DQ antigen was found in one of the 3 DR+ DP+ specimens. Thus the expression of class II antigens in normal gastric epithelia and GaCas appears to be in the order of DR, DP, and DQ. Studies on 3 GaCa cell lines (Kato III, MKN28, and MKN45) demonstrated that 1 line (Kato III) expressed DR antigen only, and the remaining lines were negative. Interferon (IFN)-gamma treatment enhanced the expression of DR antigen on Kato III cells and induced expression of DQ and DP antigens. The IFN-gamma treatment also induced expression of DR antigen but not DQ or DP antigens in 1 of the 2 negative cell lines. The induction of the class II antigens by IFN-gamma was shown to be dose dependent. However, maximal induction of DQ and DP antigens on the Kato III cells and DR antigens on MKN45 cells required 10 times more IFN-gamma than that needed for the maximal expression of DR antigen on Kato III. Northern blot analyses of cytoplasmic RNA from these cells were in agreement with and affirmed the above-described expression of the class II antigens on the cell lines. The DR antigen on the Kato III cells was capable of stimulating allogeneic lymphocytes in MLR, and its stimulatory activity was significantly enhanced by IFN-gamma. These results demonstrated a differential expression of class II antigens in the "DR, DP, and DQ order" in normal gastric epithelia, GaCa cells, and GaCa cell lines, suggesting different mechanisms acting discordantly on the expression of each of these antigens and that the DR antigen on the GaCa cell lines possesses MLR-stimulatory ability.

Animals↗
PubMed1986

HLA-DQ structural polymorphism in HLA-DR2 associated HLA-D clusters.

Three homozygous cell lines with different cellular HLA-D specificities associated with HLA-DR2 including Dw2, Dw12, DB9 displayed structural variation in the products of the DQ locus. Nonglycosylated precursor polypeptides of DQ molecules immunoprecipitated by two-dimensional polyacrylamide gel electrophoresis (2-D gel) revealed distinct differences in the patterns of DQ alpha and DQ beta chains.

Antibodies, Monoclonal↗
PubMed1986

Southern hybridization analysis of DNA polymorphism in the HLA-D region.

Restriction fragment-length polymorphisms (RFLP) were systematically analyzed by Southern hybridization with restriction endonuclease-digested genomic DNA from 28 HLA-homozygous B cell lines with Dw1-Dw19 specificity using the DR beta and DQ beta chain cDNAs as probes. These probes detected polymorphic fragments unique to each HLA-DR specificity. Furthermore, the DQ beta chain probes permitted us to distinguish between different Dw specificities with an identical DR type much more efficiently than with the DR beta chain probe. Distribution analysis of restriction fragments hybridizing to DR beta in relation to the DR and DQ specificities showed several sets of them forming ten clusters, some of which correlate with DRw53, DQw1, and DR alleles. This DNA typing technique allows the direct definition of HLA types at the gene level and provides a powerful tool for isolating genes controlling HLA-associated diseases.

DNA↗
PubMed1986

Isolation and allelic polymorphism of cDNA clones and genomic clones of HLA-DP heavy and light chains.

From a human cDNA library constructed from consanguineous HLA-homozygous cell line AKIBA (HLA-A24, Bw52, DR2, Dw12, Cp63 Cp63: a new DP type), cDNA clones encoding the heavy and light chains of an HLA-DP Cp63 alloantigen were isolated and analyzed by restriction enzyme mapping and nucleotide sequence determination. Allelic comparisons of DP alpha and DP beta cDNA sequences showed that the amino acid sequence of the DP alpha chain was less polymorphic than that of the DP beta chain. In the DP beta chain, the polymorphic region was restricted to the beta 1 domain. We also isolated and characterized 15 genomic phage clones spanning a 74 kilobase (kb) pair of the DP region which were found to contain one DP alpha gene, one DP-like alpha gene, one DP beta gene, and one DP-like beta gene. Genomic blot analyses with different HLA-DP type cell lines using DP alpha cDNA as a probe revealed EcoRI fragment length polymorphism around the DP alpha gene.

Alleles↗
PubMed1986

HLA-DR2 and Dw2 in narcolepsy and in other disorders of excessive somnolence without cataplexy.

Studies on HLA antigens were conducted in several patient populations with the following findings: (a) All 135 Japanese narcoleptic patients, eight of whom were considered to have "symptomatic" narcolepsy, were found to be HLA-DR2 and HLA-DQw1 positive. All 17 members of a subgroup of the original population were also found to be HLA-Dw2-positive. It was concluded that HLA-DR2 is a prerequisite for the development of narcolepsy and that the diagnosis of narcolepsy can be excluded if HLA-DR2 or HLA-Dw2 is negative. The distinction between idiopathic and symptomatic narcolepsy needs to be reconsidered. (b) Haplotype studies in three families with narcoleptic members enabled detection of children at high risk for narcolepsy. (c) Of the 54 patients with disorders of excessive daytime sleepiness other than narcolepsy, those with essential hypersomnia (EHS) had a higher frequency of HLA-DR2; the others had a lower frequency. The DR2-positive EHS group could include members with an incomplete form of narcolepsy; the DR2-negative EHS group had disorders essentially different from narcolepsy, although both positive and negative groups manifested hypnagogic hallucinations, sleep paralysis, and sleep onset REMs. Two further studies were conducted in subgroups of the original narcoleptic population studied. In a subgroup of 30 patients who underwent lymphocyte subset studies, no T-cell abnormalities were detected; it is unlikely that an autoimmune mechanism is involved in the development of narcolepsy. In a subgroup of 33 narcoleptic patients, Southern's blot analysis of DNA using a DQ beta probe revealed three specific restriction fragments. Further studies are necessary to locate the DNA locus that carries the susceptibility gene for narcolepsy.

Alleles↗
PubMed1985

Molecular genetic analysis of myelin-deficient mice: shiverer mutant mice show deletion in gene(s) coding for myelin basic protein.

The gene expression of myelin basic proteins (MBPs) in shiverer mutant mice was investigated by the Northern and Southern hybridization techniques. In the control mice RNA molecules from the brains which were about 2,300 nucleotides in length were hybridized to cDNA of 1.8 kb encoding for a mouse MBP, but RNA from the brains of 3-week-old shiverer mutant mice contained no detectable amount of MBP transcripts hybridizing to this probe. Moreover the shiverer mutant mice lost several restriction fragments that hybridized to the same probe in the control mice when each of the five restriction enzymes, i.e., HindIII, PstI, PvuII, AccI, and StuI, was used. These data suggest that the shiverer mutation may correspond to the deletion of a large portion of MBP exon(s) in the gene, and this deletion causes inefficient transcription leading to the depletion of MBPs in the myelin and the dysmyelination observed in these mice.

Animals↗
PubMed1985

Isolation and characterization of the cDNA clone and genomic clones of a new HLA class II antigen heavy chain, DO alpha.

From a human cDNA library constructed from a consanguineous HLA-homozygous cell line, AKIBA (HLA-A24, Bw52, DR2, Dw12, DQw1, and Cp63) (Cp63, a new SB type), a cDNA clone encoding a new HLA class II antigen heavy chain named DQ alpha was isolated, and was analyzed by Southern blot hybridization and by nucleotide sequence determination. The nucleotide sequence of the DO alpha cDNA was distinct from those of the DR alpha, the DQ alpha, and the DP alpha cDNA, but showed some characteristic features of the class II antigen alpha-chains. We also isolated and identified genomic clones specifying the DO alpha gene. Genomic analyses of cell lines with different HLA-DR serotypes with the use of the DO alpha cDNA as a probe indicated the existence of a single DO alpha gene that exhibited little restriction enzyme polymorphism.

Amino Acid Sequence↗
PubMed1983

Distribution of RNA coliphages in Senegal, Ghana, and Madagascar.

The distribution patterns of RNA coliphages (phages) in Senegal, Ghana, and Madagascar were investigated by collecting sewage samples from domestic drainage in November, 1980. In Senegal, among 65 sewage samples collected mainly from Dakar and its vicinity, 14 (22%) contained RNA phages (16 strains). By serological analysis, 13 of 16 strains were found to belong to group III. This is consistent with the distribution pattern of RNA coliphages in tropical and subtropical regions of Asia. In Ghana, however, among 106 samples collected from Accra, Suhum, and their vicinities, only seven (7%) contained RNA phages (seven strains) (groups I, II, and III [1:3:3]). In Madagascar, among 124 samples collected from Antananarivo, Moramanga, and their vicinities, seven (6%) contained RNA phages (seven strains) (groups I, II, III, and IV [1:1:1:4]). In spite of the low isolation frequency, it can be said that Madagascar appears to have a unique distribution pattern (abundance of group IV phages) which differs from that of any other countries we have examined. The generality of the distribution pattern of RNA phages in the tropical region (abundance of group III phages) was thus verified at least in Senegal.

Coliphages↗
PubMed1977

Isolation and characterization of conditional-lethal rho mutants of Escherichia coli.

Temperature-sensitive nitA (rho) mutants of E. coli were isolated; one of them was characterized as an amber mutant. These strains show the Nit phenotype (transcription of phage lambda DNA independent of the N gene) at low temperatures and are inviable at high temperatures. The mutated sites appear to be between cya and metE on the chromosome. Temperature-sensitive nitA bacteria not only permit leftward transcription of the lambda genome at a high rate in the absence of the lambda N protein, but also allow lambda growth at low temperatures. At high temperatures, phages lambda and T4 are incapable of normal development in these cells, while growth of T7 is not affected. The production of thermally unstable rho by the nitA temperature-sensitive mutant suggests that nitA is the structural gene for rho.

Anthranilate Synthase↗
PubMed1976

Isolation and genetic characterization of the nitA mutants of Escherichia coli affecting the termination factor rho.

Taking advantage of the Spi (sensitivity to P2 interference) phenomenon, bacterial mutants seemingly resistant to phage lambdasusNnin5, but sensitive to phage lambdaspi, were isolated from a strain of E. coli K12 carrying no nonsense suppressor and lysogenic for P2. A class of these mutants, designated nitA (N-independent transcription), is described here. Upon infection of the nitA mutants with a trp transducing phage lambdasusN7N53ptrp46 which carries the E. coli trpE and D genes in the CIII-att region of the lambda genome, formation of anthranilate synthetase (ASase, a complex protein of trp E and D gene products) was clearly demonstrated. In contrast, no ASase formation was observed in the parent nitA+ strain under the same conditions. The synthesis is subject to "turn off" control, and is completely repressed by the CI repressor of phage lambda. The nitA cells lysogenic for lambdaCI857susN7N53 are killed by thermal induction much more efficiently than the parent cells lysogenic for the same phage. The nitA mutants support the growth of lambdasusN7N53byp much better than the parent. These results suggest that the nitA mutation permits the early leftward and rightward transcription of the lambda genome in the absence of the N gene product. On the E. coli genetic map, nitA is located between ilv and metE, nearer to ilv. The mutant allele is recessive to the wild-type allele. The present evidence, together with results of biochemical investigations to be reported, suggests that nitA is a gene specifying the transcription termination factor rho.

Chromosome Mapping↗