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T Honjo

Publications and source records attributed to T Honjo.

At least 307 records · Page 17Linked to original sources
PubMed1987

Interleukin 5, a T-cell-derived B-cell differentiation factor also induces cytotoxic T lymphocytes.

We describe an interleukin, termed interleukin 5, that is the recombinant product previously referred to as T-cell-replacing factor (TRF), B-cell growth factor II (BCGF II), or killer-helper factor (KHF). TRF has been defined as a T-cell-derived lymphokine that acts on activated B cells as a B-cell differentiation factor. We have previously demonstrated that TRF is identical to BCGF II and induces expression of receptors for interleukin 2 (IL-2) on activated B cells. We also have reported that KHF can induce not only expression of IL-2 receptors on peanut agglutinin-binding (PNA+) thymocytes but also generation of cytotoxic T lymphocytes (CTL) in PNA+ thymocytes in the presence of IL-2. We show here that culture supernatants of T-cell hybridomas that produce TRF as well as TRF purified by high-pressure liquid chromatography (HPLC-TRF) have KHF activity and generate CTL in PNA+ thymocytes in the presence of stimulator cells and IL-2. Moreover, translation products (recombinant TRF) of Xenopus oocytes injected with cDNA encoding for murine TRF (BCGF II) also exert KHF activity. A rat monoclonal anti-TRF antibody TB13 can block generation of CTL by HPLC-TRF or recombinant TRF. These results indicate that TRF acts not only on B cells as BCGF II but also on PNA+ thymocytes as KHF. In view of the diverse activities and targets of TRF, we propose that TRF refers to a different interleukin, interleukin 5.

Animals↗
PubMed1987

Production of a monoclonal antibody useful in the molecular characterization of murine T-cell-replacing factor/B-cell growth factor II.

T-cell-replacing factor (TRF) is a T-cell-derived factor required for terminal differentiation of activated B cells to immunoglobulin-secreting cells. Previous studies have shown that a murine T-cell hybrid (B151K12) produces factor(s) that (i) induce immunoglobulin secretion by the B-cell leukemia line BCL1 and secondary anti-2,4-dinitrophenyl IgG synthesis in vitro by dinitrophenyl-primed B cells (TRF activity) and (ii) cause proliferation of the BCL1 cells [B-cell growth factor II (BCGF-II) activity]. Both activities appear to be associated with the same molecule. Here we report the production of a monoclonal antibody to murine TRF. The monoclonal antibody, designated TB13, strongly inhibited both TRF and BCGF-II activities and absorbed TRF- as well as BCGF-II-active molecules produced by B151K12 and by Xenopus oocytes that had been injected with mRNA transcribed from plasmid pSP6K-mTRF23. Inhibition was linearly dependent on the concentration of both TB13 and TRF. Monoclonal antibody TB13 did not inhibit the activities of B-cell stimulatory factor 1, interleukin 1, interleukin 2, or interleukin 3. TRF activity in dissolved samples of immunoprecipitates obtained with TB13 was recovered after NaDodSO4/PAGE, in the fractions corresponding to a protein band at Mr 46,000. Our results indicate that monoclonal antibody TB13 recognizes a molecule that has both TRF and BCGF-II activities.

Animals↗
PubMed1987

Human lymphocyte Fc receptor for IgE: sequence homology of its cloned cDNA with animal lectins.

We have purified the human lymphocyte Fc receptor specific for IgE (Fc epsilon receptor) and its soluble form by using the anti-Fc epsilon receptor monoclonal antibody H107. Using an oligonucleotide probe corresponding to the partial amino acid sequence of the soluble Fc epsilon receptor related to IgE binding factor, we cloned, sequenced, and expressed a cDNA for the receptor. The Fc epsilon receptor has 321 amino acid residues with no NH2-terminal signal sequence. The receptor was separated into two domains by a putative 24-amino acid residue transmembrane region located near the NH2-terminal end. The Fc epsilon receptor showed a marked homology with animal lectins including human and rat asialoglycoprotein receptors, chicken hepatic lectin, and rat mannose binding proteins.

Amino Acid Sequence↗
PubMed1987

Nucleotide sequences of immunoglobulin epsilon genes of chimpanzee and orangutan: DNA molecular clock and hominoid evolution.

To determine the phylogenetic relationships among hominoids and the dates of their divergence, the complete nucleotide sequences of the constant region of the immunoglobulin epsilon-chain (C epsilon 1) genes from chimpanzee and orangutan have been determined. These sequences were compared with the human epsilon-chain constant-region sequence. A molecular clock (silent molecular clock), measured by the degree of sequence divergence at the synonymous (silent) positions of protein-encoding regions, was introduced for the present study. From the comparison of nucleotide sequences of alpha1-antitrypsin and beta- and delta-globin genes between humans and Old World monkeys, the silent molecular clock was calibrated: the mean evolutionary rate of silent substitution was determined to be 1.56 X 10(-9) substitutions per site per year. Using the silent molecular clock, the mean divergence dates of chimpanzee and orangutan from the human lineage were estimated as 6.4 +/- 2.6 million years and 17.3 +/- 4.5 million years, respectively. It was also shown that the evolutionary rate of primate genes is considerably slower than those of other mammalian genes.

Animals↗
PubMed1987

Human neoplastic B cells express more than two isotypes of immunoglobulins without deletion of heavy-chain constant-region genes.

Flow cytometric analyses of surface immunoglobulins of human neoplastic B cells from four patients indicated that more than two isotypes were expressed on the surface of each patient's neoplastic B cells. Southern blot analysis of DNAs of these cells showed that each patient's neoplastic cells had the monoclonal rearrangement profile of the J segment of the immunoglobulin heavy-chain gene. Heavy-chain constant-region genes of these cells had no deletion associated with S-S recombination. Northern blot analysis of RNA from two neoplastic cells revealed that each RNA contained comparable amounts of mRNAs for two different isotypes which were identified by surface staining. These results support the hypothesis that the simultaneous expression of two different isotypes in a certain stage of B-cell differentiation is mediated by alternative RNA splicing without DNA deletion.

B-Lymphocytes↗
PubMed1987

Molecular characterization of novel reciprocal translocation t(6;14) in an Epstein-Barr virus-transformed B cell precursor.

An in vitro culture of FLEB14 cells, an Epstein-Barr virus-transformed B cell precursor containing the germ line immunoglobulin genes, gave rise to a uniclonally expanded variant, FLEB14 delta 3, which was rearranged at the immunoglobulin heavy-chain gene locus. Cytogenetic analysis showed that FLEB14 delta 3 had a novel reciprocal translocation, t(6;14)(q15;q32). Molecular cloning of the rearranged DNA fragments and determination of their nucleotide sequence revealed that the recombination event was reciprocal, imprecise, and nonhomologous and took place in the S mu region, like those found in Burkitt's lymphoma cells. We propose a molecular model to explain this genetic event which may be relevant to class switch recombination. The translocated sequence of chromosome 6 did not contain any known oncogenes, although the sequence is conserved among mammals. FLEB14 delta 3 did not show tumorigenicity.

B-Lymphocytes↗
PubMed1987

Analysis of steroid 21-hydroxylase gene in five unrelated Japanese patients with 21-hydroxylase deficiency.

DNA samples from five unrelated Japanese patients with 21-hydroxylase (21-OHase) deficiency were studied by Southern analysis using human 21-OHase cDNA. Patterns seen after digestion with not only TaqI but also KpnI showed that two out of the five patients were homozygous for a deletion of the 21-OHase B gene. This result supports the report that the 21-OHase B gene is functional. In the other three, smaller mutations might be responsible for the disorder. The parents of one of the two patients with the deletion had a common ancestor. Hybridization patterns of DNA from members of the family of the patient were consistent with an autosomal recessive mode of inheritance of the deletion that correlates with the clinical phenotype. The deletion segregated with HLA-Aw 24; Bw 61; Cw 3. Heterozygous carriers of 21-OHase deficiency could be detected by comparing the patterns as well as the HLA haplotypes in this family. The application of the family study to the prenatal diagnosis is also discussed.

Adrenal Hyperplasia, Congenital↗
PubMed1987

The T-cell receptor gene rearrangements in T-lineage tumors without OKT-3,4,6,8 markers.

In the human system, discrete stages (I, II, and III) of intrathymic ontogeny have been defined on the basis of monoclonal antibody probes directed at unique T-lineage-specific surface glycoproteins. We have examined the relationship among T-cell receptor gene rearrangements and cell surface antigen expressions in T-cell malignancies. Twelve of 15 cases had the rearranged T-cell receptor beta chain gene, indicating that they represent cells already committed to the differentiated T-cell lineage at the gene level and are monoclonally proliferating regardless of the variable expression of surface antigens. We examined five cases of the earliest identifiable T-lineage cells (stage I) expressing WT-1 antigen without OKT-3, 4, 6, 8 antigens. Among them, two cases did not reveal the T-cell receptor beta chain gene rearrangements. In contrast, three cases demonstrated the T-cell receptor beta chain gene rearrangements even in stage I by the criteria of surface antigen expressions in contrast to the previous findings. Thus, we conclude that somatic rearrangement of the T-cell receptor gene of the beta chain occurs at the stage I level (early thymocyte) in the T-cell differentiation scheme. The phenotypically defined stage I T-cells consist of two populations with or without rearrangements of the T-cell receptor gene.

Antibodies, Monoclonal↗
PubMed1987

Relationship of human cord blood mononuclear cell lines, established by the HTLV-I integration, to expression of T-cell phenotypes and the T-cell receptor gene rearrangement.

The HTLV-I integrated cell lines originated from human cord blood mononuclear cells were examined for the T-cell receptor beta chain gene rearrangement in conjunction with immunological phenotype analysis. Five of seven cell lines contained the rearranged T-cell receptor beta chain gene. Interestingly, most of the rearranged lines failed to express the T cell differentiation antigens, OKT 4 and 8, though their positive expression of Leu 1 antigen indicated the commitment to the T-cell lineage. On the other hand, two cell lines retained the germ-line configuration of the beta chain gene, while phenotypical examination revealed that the two cell lines have distinct T-cell antigens. Non-rearranged cell lines have proved to be nearly monoclonal from HTLV-I integration pattern and/or surface marker clonality. Thus, the relationship between the immunological phenotypes and the T-cell receptor gene rearrangement observed in the T-cell lineage is not strict and often dissociates. A possible involvement of HTLV-I infection on the dissociation between phenotype and genotype is discussed from the viewpoint of phenotypical modulation.

Antigens, Surface↗
PubMed1987

[Molecular cloning of cDNAs encoding B-cell growth factors].

The proliferation and maturation of antigen-stimulated B cells are regulated by several soluble factors derived from macrophages and T cells. These soluble factors have been functionally divided into two groups; B-cell growth factor (BCGF) and B-cell differentiation factor (BCDF). However, this distinct classification and identification of B-cell factors should be reexamined after the recent cloning of cDNA encoding IgG1 induction factor (IL-4) from a 2.19 T-cell line. This factor induces not only an elevated IgG1 response in B cells activated by lipopolysaccharides but also hyper-Ia expression in B cells. IL-4 is identical to B-cell stimulating factor-1 (BSF-1) which induces DNA synthesis when given together with anti-IgM antibodies. Furthermore, this lymphokine has growth factor activities for both T and mast cells. Another well characterized B-cell factor is T-cell replacing factor (TRF). Although TRF was previously classified as a BCDF, a partially purified preparation of TRF was suggested to have BCGF II activity. The identity of TRF with BCGF II was proved by its cDNA cloning and the name IL-5 was proposed for this lymphokine.

Amino Acid Sequence↗
PubMed1986

Interleukin 1 alpha mRNA in virus-transformed T and B cells.

IL-1 alpha cDNA clone was isolated from a T cell line infected by the human T lymphotropic retrovirus type-I (HTLV-I/ATLV). We found significant amounts of mRNA hybridizing to IL-1 alpha cDNA not only in HTLV-I-transformed T cells but also in Epstein-Barr Virus-transformed B cells. A part of IL-2 receptor inducing activity in Adult T cell leukemia (ATL) cell line seems to be due to IL-1 alpha.

B-Lymphocytes↗
PubMed1986

Organization and evolution of variable region genes of the human immunoglobulin heavy chain.

We have isolated 23 different cosmid clones of the heavy-chain variable region genes (VH) of human immunoglobulin. These clones encompass about 1000 X 10(3) base-pairs of DNA containing 61 VH genes. Characterization of the 23 clones by Southern blot hybridization showed that VH genes belonging to different families were physically linked in many regions. Cluster 71, which was analyzed in detail, comprised seven VH segments arranged in the same orientation with different intervals. This clone contained internal homology regions, each carrying two VH segments of different families. Comparison of the nucleotide sequences of VH segments within each family showed that profiles of accumulation of mutations in framework (FR) and complementarity-determining (CDR) regions were different. CDR had more mutations at amino-acid-substituting positions than at silent positions, whereas FR had the reverse distribution of mutations. Five out of seven VH segments of this cluster were pseudogenes containing various mutations. VH pseudogenes were classified into two distinct groups; one with a few replacement mutations (conserved pseudogenes), and the other with rather extensive mutations (diverged pseudogenes). The possibility that conserved pseudogenes serve as a reservoir of VH segments is discussed.

Base Sequence↗
PubMed1986

Expression and rearrangement of the alpha, beta, and gamma chain genes of the T cell receptor in cloned murine large granular lymphocyte lines. No correlation with the cytotoxic spectrum.

Using cloned murine large granular lymphocyte (LGL) lines, the expression and the rearrangement of the alpha, beta, and gamma chain genes of the T cell receptor (TCR) were analyzed. Morphological, phenotypical, as well as functional studies indicated that the LGL lines were identical to normal, endogenous NK cells. Northern blot hybridization analysis indicated that the full-length transcripts of all the alpha, beta, and gamma chain genes were expressed in most of the LGL lines, including two lines derived from athymic nude mice. In one line, SPB, however, no transcript of the gamma chain gene was detected, whereas the alpha and beta chain genes were clearly expressed. In every LGL line studied, all of the alpha, beta, and gamma chain genes were rearranged. Conforming to the results of Northern blot hybridization study, the gamma chain gene of the SPB line was aberrantly rearranged, whereas those of all the other lines were productively rearranged. The results clearly revealed that NK cells represented a population of lymphocytes genetically committed to the T cell lineage. It was also suggested that the expression and rearrangement of the TCR genes of NK cells might occur in a thymus-independent fashion. An SPB line without expression of the gamma chain gene could exhibit NK activity indistinguishable from other NK lines. Furthermore, the rearrangement patterns of the beta chain gene did not correlate with the specificity of the cytotoxic activity. These results strongly suggested that the cytotoxic activity in NK cells was not directly mediated by TCR on them. We particularly noted that the beta chain gene of most independently established LGL lines showed identical patterns of rearrangement, indicating that they used the same V beta and J beta gene segments. The significance of the restricted pattern of rearrangement of the beta chain gene in LGL lines, as well as the possible functional roles of TCR on NK cells, was discussed.

Animals↗
PubMed1986

Preferential transcription of HTLV-I LTR in cell-free extracts of human T cells producing HTLV-I viral proteins.

The promoters of the adenovirus 2 major late gene, the mouse beta-globin gene, the mouse immunoglobulin VH gene and the LTR of the human T-lymphotropic retrovirus type I were tested for their transcription activities in cell-free extracts of four cell lines; HeLa, CESS (Epstein-Barr virus-transformed human B cell line), MT-1 (HTLV-I-infected human T cell line without viral protein synthesis), and MT-2 (HTLV-I-infected human T cell line producing viral proteins). LTR was preferentially transcribed in the extracts of MT-2 although the other three genes were transcribed with relatively constant efficiencies in different extracts. The results agree well with the previous in vivo studies on the promoter activity of HTLV-I LTR. Mixing of HeLa and MT-2 extracts revealed the presence of a LTR-specific stimulating activity in MT-2 extracts.

Cell Line↗
PubMed1986

A joining-diversity-joining complex generated by inversion mechanism and a variable-diversity complex in the beta-chain gene of the human T-cell receptor.

We have analysed an inactive allele of the beta-chain gene of the T-cell receptor in a human T-cell line HPB-ALL. Comparison with germline sequences showed that HPB-ALL has a joining (J)-diversity (D)-J complex recombined in head-to-head configuration and a variable (V)-D complex in tail-to-tail configuration. These results demonstrate that the inversion mechanism functions in the beta-chain gene of the T-cell receptor. The presence of the V-D complex suggests that V-D recombination could occur prior to D-J recombination although there is no definite proof that the V-D complex is an intermediate to form the V-D-J complex.

Base Sequence↗
PubMed1986

Expression of interleukin 2 receptors on interleukin 3-dependent cell lines.

Several mouse IL 3-dependent cell lines, IC2, LT4, FDC-P2, and PB-3C, derived from spleen or bone marrow cells were shown to express low affinity receptors for IL 2 (Kd; 0.5 to 8 X 10(-8) M). High affinity receptors for IL 2 were not detected on the IL 3-dependent cells within the experimental limitation of this study. The clones did not respond to IL 2 at all at the concentration as high as 25 micrograms/ml. The number of the receptors expressed on those clones was estimated to be 0.2 to 2 X 10(5)/cell, which is comparable with the number of those on IL 2-dependent T cell clones. Expression of IL 2 receptor was confirmed in mRNA levels for both IC2 and LT4 cells. A relatively low level expression of one (4.5 Kb) of four IL 2 receptor mRNA species was observed with those IL 3-dependent clones compared with IL 2-dependent T cells. It seems that these low affinity receptors may be expressed on IL 3-dependent cells that undergo differentiation or maturation in mast cell and some myeloid cell lineages.

Animals↗