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Biomedical subjects

Y Hinuma

Publications and source records attributed to Y Hinuma.

At least 37 records · Page 2Linked to original sources
PubMed1992

Human sera from varicella-zoster virus (VZV) infections cross-react with human T cell leukaemia virus type 1 (HTLV-1): common epitopes in VZV gene 22 protein and HTLV-1 p19 gag protein.

Twenty-nine of 100 sera from patients recently infected with varicella-zoster virus (VZV) were found to cross-react with human T cell leukaemia virus type 1 (HTLV-1) antigen in the particle agglutination (PA) assay using HTLV-1 antigen-coated gelatin particles. Anti-VZV IgM antibodies were shown to be responsible for this cross-reactivity. Western blot analysis revealed that PA-positive anti-VZV sera reacted with the HTLV-1 gag p19 protein in HTLV-1-infected cells and recombinant p19 protein produced in Escherichia coli. By using a truncated p19, the cross-reactive region was located to the C-terminal 17 amino acids of p19. One oligopeptide derived from the C terminus, PQIPPPYVEPT (amino acids 115 to 125), was capable of inhibiting PA, suggesting that this peptide carries the cross-reactive epitope. A homologous sequence was found in the VZV gene 22 protein by database analysis, and the oligopeptide TNIPPPLALLR (amino acids 1330 to 1340) had the ability to inhibit PA. These findings suggest that some IgM antibodies against the VZV gene 22 protein produced in the early phase of VZV infection are cross-reactive with the HTLV-1 gag p19 protein because they recognize an antigenic determinant containing an IPPP tetrapeptide.

Agglutination Tests↗
PubMed1992

Human T cell leukaemia virus type 1 p21X mRNA: constitutive expression in peripheral blood mononuclear cells of patients with adult T cell leukaemia.

Although the p21X protein of human T cell leukaemia virus type 1 (HTLV-1) is generally thought to be expressed from a doubly spliced mRNA transcript (tax/rex mRNA) that encodes the p40tax, p27rex and p21X proteins, we have shown previously that a novel, alternatively spliced mRNA transcript (p21X mRNA) is responsible for p21X production in HTLV-1-infected cell lines. In the present study, we analysed expression of p21X mRNA and tax/rex mRNA in uncultured and cultured peripheral blood mononuclear cells (PBMCs) from eight patients with adult T cell leukaemia by using a quantitative polymerase chain reaction coupled to reverse transcription. The results demonstrated that the expression of p21X mRNA occurs constitutively in all uncultured and cultured PBMCs, whereas the expression of tax/rex mRNA is inducible in the cultured PBMCs, as described previously. In uncultured and cultured PBMCs from the one specimen in which p21X mRNA was highly expressed, the p21X protein was detectable by Western blotting. On the other hand, p27rex protein was detectable only after cultivation. These findings indicate that p21X mRNA is constitutively expressed in vivo and is responsible for production of p21X protein.

Adult↗
PubMed1992

Impaired long-term T cell immunity to Epstein-Barr virus in patients with nasopharyngeal carcinoma.

The long-term T cell immunity to Epstein-Barr virus (EBV) is considered to play an important role in suppressing proliferation of EBV-infected B cells and outgrowth of EBV-associated tumors. It can be manifested and quantified by the EBV-induced focus regression assay. In the present study, we examined the strength of T cell immunity to EBV in patients with nasopharyngeal carcinoma (NPC) and other cancers originating from the head and neck region. In contrast to patients with other types of cancers, including EBV-negative NPC, patients with EBV-positive NPC were found to have a profound impairment in the long-term T cell immunity to EBV.

Adolescent↗
PubMed1992

Identification of membrane antigen C33 recognized by monoclonal antibodies inhibitory to human T-cell leukemia virus type 1 (HTLV-1)-induced syncytium formation: altered glycosylation of C33 antigen in HTLV-1-positive T cells.

We isolated four monoclonal antibodies (MAbs), M38, M101, M104, and C33, which were capable of inhibiting syncytium formation induced in a human T-cell line, MOLT-4-#8, by coculture with human T-cell leukemia virus type 1 (HTLV-1)-positive human T-cell lines. The MAbs had, however, no inhibitory activity on syncytium formation induced in a human osteosarcoma line, HOS, by HTLV-1-positive T-cell lines. They also did not inhibit syncytium formation induced in MOLT-4-#8 by human immunodeficiency virus type 1-positive MOLT-4. All MAbs reacted with various human cell lines of lymphoid and nonlymphoid origins, including HTLV-1-positive T-cell lines. Furthermore, they all reacted with a murine A9 clone containing human chromosome 11 fragment q23-pter. Two MAbs, M104 and C33, immunoprecipitated a membrane antigen with the same molecular size. The antigen (henceforth called C33 antigen) was about 40 to 55 kDa in HTLV-1-negative Jurkat, CEM, MOLT-4, and normal peripheral blood CD4-positive human T cells and about 40 to 75 kDa in HTLV-1-positive C91/PL, TCL-Kan, MT-2, and in fresh HTLV-1-transformed CD4-positive human T-cell lines. Pulse-chase experiments revealed that C33 antigen was synthesized as a 35-kDa precursor that was then processed to 41 to 50 kDa in MOLT-4 and to 44 to 70 kDa in C91/PL. In the presence of tunicamycin, a 28-kDa protein was synthesized. The conversion from 35 kDa to 41 to 50 kDa in MOLT-4 and to 44 to 70 kDa in C91/PL was inhibited by monensin. Treatment with N-glycanase alone, but not with sialidase and O-glycanase in combination, completely removed the sugar moiety of C33 antigen from both HTLV-1-negative Jurkat and HTLV-1-positive C91/PL. Therefore, C33 antigen has only N-linked carbohydrates, the modification of which appears to be substantially altered in the presence of the HTLV-1 genome.

Antibodies, Monoclonal↗
PubMed1991

A novel alternatively spliced viral mRNA transcribed in cells infected with human T cell leukemia virus type 1 is mainly responsible for expressing p21X protein.

The pX sequence of human T cell leukemia virus type 1 (HTLV-1) has been thought to be expressed as a doubly spliced mRNA that codes for p40tax, p27rex and p21X. However, we identified a novel alternatively spliced mRNA in the HTLV-1 infected cells by using reverse transcription followed by the polymerase chain reaction. This mRNA contains only the first and third exons of the doubly spliced mRNA and encodes only p21X. Our data that this mRNA is responsible for expressing p21X exists in most of HTLV-1 infected cells strongly suggests that p21X may play a crucial role for HTLV-1 replication.

Base Sequence↗
PubMed1989

Cell line-dependent response of the enhancer element of simian virus 40 to transactivator p40tax encoded by human T-cell leukemia virus type I.

The trans-acting transcriptional factor p40tax of human T-cell leukemia virus type I (HTLV-I) can activate expression not only of its own viral genes but also of other viral and cellular genes. We examined the cis-acting sequences in the simian virus 40 (SV40) enhancer required for its activation by HTLV-I p40tax. Experiments with chloramphenicol acetyltransferase constructs bearing the SV40 enhancer elements revealed that p40tax-dependent transactivation of the SV40 enhancer is mediated through the C element that contains the typical sequence for binding of a nuclear factor NF-kappa B. Activation of the C element by p40tax was seen in a limited set of cell lines as was also seen with the whole enhancer of SV40. Binding of NF-kappa B or NF-kappa B-like factor to the SV40 C element increased when p40tax was expressed. The fact that HTLV-I p40tax utilizes a cellular regulatory mechanism to transactivate the SV40 enhancer in a cell-dependent manner may have implications for the pathogenesis of adult T-cell leukemia.

Base Sequence↗
PubMed1989

Patterns of migration indicate sexual transmission of HTLV-I infection in non-pregnant women in Papua New Guinea.

The prevalence of infection with human T-cell leukaemia virus (HTLV-I) was studied in Madang Province on the north coast of Papua New Guinea. Serum specimens collected from non-pregnant women in 17 villages were tested for anti-HTLV-I by gelatin particle agglutination screening and confirmed by immunofluorescence and Western blotting. Overall, 13.9% of subjects were antibody-positive, with the prevalence of antibodies varying from less than 10% to 30% in villages situated less than 10 km apart. Two groups of migrant women were identified, and in both a parity-related increase in antibody prevalence which occurred only after marriage suggested that the predominant mode of transmission in migrant women was sexual. There was no parity-associated increase in anti-HTLV-I in indigenous women, and in contrast to migrant women, nulliparous indigenous women had a high prevalence of antibody (16.8% vs. 0%; p = 0.005). Vertical transmission cannot be excluded in indigenous women. No correlation was detected between the prevalence of anti-HTLV-I and a variety of indices of malarial infection.

Emigration and Immigration↗
PubMed1989

Electroporation: application to human lymphoid cell lines for stable introduction of a transactivator gene of human T-cell leukemia virus type I.

Conditions were developed for stable introduction of foreign DNA into human lymphoid cell lines by electroporation. To introduce stably the p40 gene of human T-cell leukemia virus type I (HTLV-I) into the human lymphoid cell line Jurkat, the p40 expressing plasmid, pMAXRHneo-1, which carries the neo resistant gene, was transfected into Jurkat cells at a voltage of 2500 V and capacitance of 21.7 microF, and stable transformants were screened for neo (G418) resistance. The frequency of transformants was more than one per 2 x 10(5) cells used initially. Clones that were resistant to G418 were shown to have the p40 gene integrated into the host genome and to express mRNA and protein from the introduced plasmid. Expression of p40 in the transformed Jurkat cells was also confirmed by testing the trans-activating effect of HTLV-I enhancer by p40. High frequencies of stable transformations of 10(-4) to 10(-6) were also reproducibly obtained by electroporation of the human T cell lines HSB-2 and TALL-1, a human B cell line Raji, a human monocytic cell line U937, and a human erythroleukemia cell line K562. These results demonstrate that electroporation is a very efficient method for introducing foreign DNA into human lymphoid cell lines.

Blotting, Northern↗
PubMed1989

Emergence of large plaque-producing clones of human immunodeficiency virus (HIV) in vitro.

Large plaque-inducing clones were obtained from small plaque-inducing parental clones of human immunodeficiency virus (HIV) by the plaque-cloning method. The cloned HIVs that formed large and small plaques were studied as follows: 1) infectivity was determined by the ratio of plaque-forming units (PFU) to reverse transcriptase (RT) activity; 2) viral growth was assessed by the amount (RT activity) of virus after infection; and 3) HIV long terminal repeat (LTR)-linked gene expression of the viruses was measured by chloramphenicol acetyltransferase (CAT) assay using persistently infected MOLT-4 cells. Results showed that clones producing large plaques showed similar or slightly lower infectivity but higher virus production, faster viral growth, and higher gene expression activity than clones producing small plaques. These analyses revealed that clones producing large plaques could replicate more rapidly than those producing small plaques. Restriction enzyme map analysis of these cloned viruses showed that they were also genetically different. These results suggest that the changes in the biological features observed here might be due to mutation during the cloning procedure.

DNA, Viral↗
PubMed1989

Functional mapping of the activity of the R region in the human T-cell leukemia virus type I long terminal repeat to increase gene expression.

We previously demonstrated the activity of the R fragment in the long terminal repeat of human T-cell leukemia virus type I for elevation of the level of gene expression. In this study, the fragment was deleted with BAL31 nuclease to determine its functional domain. Series of the shortened R fragments were linked to the simian virus 40 promoter unit, which regulated expression of a reporter gene. Examination with the R fragments deleted from the 5' and 3' ends showed that borders of the functional domain were mapped within nucleotide positions 458 to 473 for the 5' end and nucleotide positions 559 to 594 for the 3' end, respectively. Thus we conclude that a 136-base-pair fragment corresponding to the second half of the R region was sufficient to allow elevation of the level of gene expression.

Base Sequence↗
PubMed1988

Species-dependent antigenicity of the 34-kDa glycoprotein found on the membrane of various primate lymphocytes transformed by human T-cell leukemia virus type-I (HTLV-I) and simian T-cell leukemia virus (STLV-I).

Sixteen monoclonal antibodies (MAbs) against TA34 antigen found on the surface of human T-cell leukemia virus type-I (HTLV-I) infected cells were prepared. These MAbs and one previously prepared anti-TA34 MAb (TAG34) recognized 34-kDa peptide not only in HTLV-I-infected cells, but also in cells infected with simian T-cell leukemia virus (STLV-I), which is analogous in antigenicity and gene structure to HTLV-I. Radioimmuno-precipitation (RIP) tests with the MAbs showed that TA34 antigen had at least 3 overlapping epitope groups. The antigenicities of the TA34 antigens of HTLV-I-infected cells derived from various primates were investigated by immunofluorescence staining using 9 anti-TA34 MAbs. Cells from humans, apes and Old World monkeys reacted with all these antibodies, whereas cells from New World monkeys were stained by most of the antibodies, but little if at all by the remaining 2 (5A8 and TAG34). Similar results were obtained with various primate cells infected with STLV-I. All 17 MAbs used recognized a 22-kDa peptide in HTLV-I-infected cells cultured in the presence of tunicamycin. When incubated with 1% 2-mercaptoethanol at pH 7.2 at 37 degrees C, TA34 antigen lost its reactivity with TAG34, suggesting that the antigen has an intramolecular S-S bond. Twenty sera of adult T-cell leukemia (ATL) patients did not react with TA34 antigen in RIP tests.

Animals↗
PubMed1988

Phorbol esters can persistently replace interleukin-2 (IL-2) for the growth of a human IL-2-dependent T-cell line.

A selected clone from an IL-2-dependent human T-cell line was persistently propagated in the presence of phorbol esters with the ability to activate protein kinase C (PKC), such as 12-O-tetradecanoylphorbol-13-acetate (TPA) or phorbol-12,13-dibutylate (PDBu). Thus, a TPA(PDBu)-dependent T-cell line, designated TPA-Mat, was established from IL-2-dependent T cells. The TPA-dependency of TPA-Mat was not lost during cultivation for more than a year in the presence of TPA, and TPA-Mat cells still showed IL-2-dependent growth. However, the TPA (PDBu)-dependent growth of TPA-Mat did not seem to be mediated by an autocrine mechanism of IL-2 or by any other growth factor production, because these factors were not detected in TPA-Mat cell supernatants. Therefore, the phorbol esters substituted for IL-2 and may be directly involved in transduction of growth signals in TPA-Mat cells. Although activity of PKC was down-regulated, messenger ribonucleic acid (mRNA) of the PKC beta-gene was detected in TPA-Mat cells cultured with PDBu. Furthermore, the growth of TPA-Mat cells was stimulated not only by phorbol esters but also by nonphorbol ester tumor promoters with the ability to activate PKC. These observations suggest that the sustained activation of PKC by the phorbol esters could induce continuous growth of the IL-2-dependent TPA-Mat cells.

Cell Line↗
PubMed1988

Two major subgroups of human T-cell leukemia virus-1 in Japan.

T lymphocytes of patients with human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy (HAM) were cultured. After cultivating for several months, HAM-derived cell lines were tested for the presence of HTLV-1 proviral genome. We have found two major subgroups, the SacI type and the PstI type, of HTLV-1 by the restriction map analysis. They were almost equally distributed among HAM patients. We have also found two types of the provirus in DNA derived from fresh peripheral blood lymphocytes (PBL) or lymph node cells of adult T-cell leukemia/lymphoma (ATL) patients. The PstI type proviruses were predominant in ATL patients. It was concluded that two major subgroups of HTLV-1 exist in Japan and both types have an ability to cause either of two diseases, ATL or HAM.

Cell Line↗
PubMed1988

Selective inhibition of high- but not low-affinity interleukin 2 binding by lectins and anti-interleukin 2 receptor alpha antibody.

The present study demonstrated that various reagents can specifically reduce the affinity of high-affinity interleukin 2 receptor (IL-2R) but not that of low-affinity IL-2R. They included lectins such as wheat germ agglutinin (WGA), concanavalin A and phytohemagglutinin, and a chemical cross-linker, glutaraldehyde, in addition to anti-IL-2R monoclonal antibodies, HIEI and H-47. The affinity of the high-affinity IL-2R was reduced when the cells were treated with WGA or H-47 before, but not after, addition of 125I-labeled interleukin 2 (IL-2). Their inhibitory effects were also demonstrated by the chemical cross-linking method. On treatment with the reagents, the IL-2 binding to both IL-2R alpha and beta chains was inhibited and these inhibitory effects were seen only when the reagents were added before IL-2 addition, like their high-affinity reducing effects. These results support a supposition that the high affinity IL-2R is generated by assembly of the alpha and beta chains, and suggest that the IL-2 binding to IL-2R alpha and beta chains could induce stable constitution of the high-affinity state of IL-2R, but these affinity modulating reagents could perturb the optimum association between alpha and beta chains to generate the high-affinity IL-2R.

Antibodies, Monoclonal↗
PubMed1988

Sporadic carriers of human T-lymphotropic virus type I in northern Egypt.

Sera from 3,158 individuals living in northern Egypt were tested for the presence of antibodies against human T-lymphotropic virus type I (HTLV-I) by the newly developed particle agglutination (PA) test. Ten sera gave a positive reaction in the PA test. Eight of these sera were examined further by Western blotting and all of them gave several bands corresponding to HTLV-I structural proteins. Two of the 8 sera gave positive results in the indirect immunofluorescence test. The results indicate the presence of HTLV-I carriers in this area, although at very low incidence (0.063%).

Adult↗