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Biomedical subjects

S Miyatake

Publications and source records attributed to S Miyatake.

At least 109 records · Page 6Linked to original sources

T-cell activation signals and human T-cell leukemia virus type I-encoded p40x protein activate the mouse granulocyte-macrophage colony-stimulating factor gene through a common DNA element.

Activation of T cells by an antigen, a mitogen, or a combination of a phorbol ester (12-O-tetradecanoylphorbol-13-acetate [TPA]) and a calcium ionophore (A23187) leads to induction of a set of lymphokine genes. Treatment of human T-cell leukemia line Jurkat by a mitogen or p40x, a transactivator protein encoded by human T-cell leukemia virus type I, activates many transfected lymphokine genes in a transient transfection assay. To study the mechanism of lymphokine gene induction, we examined the effects of mitogen stimulation and p40x on the gene for the mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) in Jurkat cells. Deletion and mutation analyses showed that the 5'-flanking region of the gene for the GM-CSF is composed of two types of regulatory elements. One sequence, located at positions -95 to -73, determines response to stimulation by either TPA-A23187 or p40x. This region contains conserved lymphokine element 2, which appears in the gene for interleukin 3 (IL-3) and is followed by a GC-rich stretch. This GC-rich stretch alone specifies inducible response to p40x but not to TPA-A23187. Another sequence, located at positions -113 to -96 upstream of a TATA-like sequence, mediates inducible response to p40x but not to TPA-A23187. This sequence includes conserved lymphokine element 1, which appears in several lymphokine-cytokine genes, such as those for IL-3, G-CSF, and IL-2. We previously showed that the simian virus 40 early region promoter was also induced by a mitogen or p40x in Jurkat cells. Deletion analysis showed that the minimum region require for stimulation by both signals are identical. These results, which indicate that p40(x) stimulates transcription of the gene for the GM-CSF or the simian virus 40 early region promoter through the same DNA element or an overlapping DNA element required for induction by a mitogen, lend further support to the notion that p40(x) can exert its function by activating a component(s) of the T-cell signal transduction pathway which is activated by an antigen or a mitogen.

Animals↗

Specific cytotoxic activity of T lymphocyte clones derived from a patient with gliosarcoma.

Eleven lymphocyte clones were established from the peripheral blood lymphocytes of a patient with gliosarcoma by means of autologous tumor stimulation and the limiting-dilution technique with recombinant interleukin-2. Ten of the 11 clones were cytotoxic against the autologous tumor cell line GI-1. Seven of the 10 clones were also cytotoxic against allogeneic brain-tumor lines and HeLa cells, one clone was cytotoxic against several target cells, and two clones were specifically cytotoxic against GI-1 and allogeneic brain-tumor cells. One of the 11 clones was not cytotoxic against any target cells tested. Lymphokine-activated killer cells induced by recombinant interleukin-2 alone exhibited cytotoxic activity against all target tumor cells tested. Surface phenotypic analysis revealed that all lymphocyte clones expressed CD3 antigen, some expressed CD4 antigen, and others expressed CD8 antigen. These clones seemed to be antigen-specific cytotoxic T lymphocyte clones. Analysis with these antigen-specific cytotoxic T lymphocyte clones may be useful in the elucidation of tumor-specific or tumor-associated antigens on autologous tumor cells.

Antigens↗

Induction of human glioma-specific cytotoxic T-lymphocyte lines by autologous tumor stimulation and interleukin 2.

Two human glioma-specific cytotoxic T-lymphocyte (G-S-CTL) lines were established by autologous tumor stimulation (ATS) with the aid of lectin free interleukin 2 (IL 2). Coculture of patient's peripheral blood lymphocytes and autologous irradiated glioma cells and subsequent addition of partially purified IL 2 enhanced the tumoricidal activity of the lymphocytes. These CTL lines possessed cross-cytotoxic activity against autologous allogeneic glioma cells and exhibited low cytotoxic activity against non-glial tumor cells. They did not lyse autologous lymphoblasts. This phenomenon suggested the existence of a common glioma-specific antigen recognized by the CTL lines. T-cell subset depletion test revealed that the major surface phenotype of G-S-CTL line, responsible for cytotoxic activity was OKT 3 positive, OKT 4 negative and OKT 8 positive. G-S-CTL lines were composed of a low proportion of OKT 8 positive subpopulation after primary ATS and successive propagation with IL 2. The proportion of OKT 8 positive subpopulation was increased by secondary ATS, which enhanced the cytotoxic activity to glioma cells more effectively.

Adult↗

Immunohistochemical analysis of infiltrating lymphocytes in central nervous system tumors.

To investigate cell-mediated immune responses to central nervous system tumors, we immunohistochemically analyzed 32 operative specimens, including 19 primary tumors, 5 recurrent tumors, and 8 metastases, for the presence of infiltrating T lymphocytes. In 1 patient, an additional sample of normal brain was studied. Using monoclonal antibodies against T lymphocyte surface markers with a peroxidase technique on frozen sections, we determined that a mild lymphocytic response was present in 3 of 7 primary glial tumors, 1 of 4 recurrent glial tumors, and in 3 of 9 primary meningiomas. The predominant subset was Leu 2, or suppressor/cytotoxic. In contrast, 5 of 7 intracranial metastatic tumors and 1 extracranial metastasis showed marked infiltration with an overall Leu 3, or helper/inducer, predominance. The remainder of the specimens, including 1 recurrent meningioma, 3 neurinomas, and the normal brain sample, were free of infiltrates. Permanent sections revealed an overall pattern of lymphocytic infiltration similar to that of frozen sections. Although additional studies such as electron microscopy are required to establish definitively the lymphocytic nature of the infiltrates, these results support the concept of the ability of the body to mount a cell-mediated response against central nervous system tumors and imply a differential response to primary and secondary tumors.

Adolescent↗

[Pharmacokinetics and toxicity of intrathecal administration of recombinant interleukin 2].

In order to contribute to the development of adoptive immunotherapy against malignant brain tumors, the pharmacokinetics and toxicity of intrathecally administered recombinant interleukin-2 in dogs and human patients were analyzed. The pharmacokinetics showed that a high concentration of IL-2 was maintained in the intrathecal cavity in both dogs and human (t1/2 = 1.41 and 1.68 hours, respectively) after administration. However, no activity of IL-2 was detected in the cerebrospinal fluid after the systemic administration of rIL-2 in one dog. No meningitis, ventriculitis or degeneration of neurons was seen histopathologically in dogs 3 weeks after the intrathecal administration of rIL-2 (200 units). A high concentration of IL-2 in the tumor cavity was maintained for a very long time (t1/2 = 14.8 hours) after the intratumoral administration of rIL-2 in one of the patients. Although low-grade fever and mild headache were sometimes observed after the intrathecal administration of rIL-2 in patients, there was no other side effect mentioned. Intrathecal or intratumoral administration of rIL-2 appeared to be an valuable procedure which should be evaluated in conjunction with adoptive immunotherapy against malignant brain tumors.

Adult↗

Structure of the chromosomal gene for granulocyte-macrophage colony stimulating factor: comparison of the mouse and human genes.

A cDNA clone that expresses granulocyte-macrophage colony stimulating factor (GM-CSF) activity in COS-7 cells has been isolated from a pcD library prepared from mRNA derived from concanavalin A-activated mouse helper T cell clones. Based on homology with the mouse GM-CSF cDNA sequence, the mouse GM-CSF gene was isolated. The human GM-CSF gene was also isolated based on homology with the human GM-CSF cDNA sequence. The nucleotide sequences determined for the genes and their flanking regions revealed that both the mouse and human GM-CSF genes are composed of three introns and four exons. The organization of the mouse and human GM-CSF genes are highly homologous and strong sequence homology between the two genes is found both in the coding and non-coding regions. A 'TATA'-like sequence was found 20-25 bp upstream from the transcription initiation site. In the 5'-flanking region, there is a highly homologous region extending 330 bp upstream of the putative TATA box. This sequence may play a role in regulation of expression of the GM-CSF gene. These structures are compared with those of different lymphokine genes and their regulatory regions.

Amino Acid Sequence↗

Structure of the chromosomal gene for murine interleukin 3.

We have isolated the mouse interleukin 3 (IL-3) gene from a mouse sperm DNA library based on homology with the mouse mast-cell growth-factor (MCGF) cDNA sequence. The nucleotide sequence determined for the gene and its flanking regions reveals that the IL-3 gene is composed of four introns and five exons. The nucleotide sequence of the exons agrees with that determined for the MCGF cDNA. A "TATA"-like sequence preceded by a G + C-rich region is found in the 5' flanking region. At the 3' region of the second intron are nine repeats of a closely related 14-base-pair (bp) sequence. These repeated sequences share extensive homology with a 20-bp repeated sequence found in the human genome, which was shown to have enhancer activity. Eight out of nine repeats form a 73-bp duplicated sequence and each 73-bp repeat contains sequences homologous to the core sequence suggested for enhancer elements. These sequences may play a role in the expression of the IL-3 gene in concanavalin A- or antigen-stimulated T lymphocytes. Stable transformants of L cells generated by co-transformation of the IL-3 gene with pSV2neo constitutively express MCGF activity indicating that the isolated gene is functional in vivo.

Animals↗