Biomedical subjects

D Y Mochizuki

Publications and source records attributed to D Y Mochizuki.

At least 19 recordsLinked to original sources

PubMed1991

Administration of IL-7 to mice with cyclophosphamide-induced lymphopenia accelerates lymphocyte repopulation.

Lymphopenia was induced in mice by a single injection of cyclophosphamide. IL-7 or a control protein were administered to the mice twice daily and the cellularity and composition of the spleen, lymph node, bone marrow, and thymus were determined at various time points thereafter. In comparison to the control cyclophosphamide-treated mice, animals receiving cyclophosphamide and IL-7 had an accelerated regeneration of splenic and lymph node cellularity. There was no significant difference in the rate of recovery of the bone marrow and thymus of the control and IL-7-treated mice. Assessment of the pre-B cell compartment revealed a dramatic increase in total pre-B cell numbers in the spleen and bone marrow of the IL-7-treated mice as measured by both flow microfluorimetry and a pre-B cell colony-forming assay. This was followed in a few days by a significant increase in surface IgM+B cell numbers to levels above normal values in both the spleen and lymph node. IL-7 administration to cyclophosphamide-treated mice also resulted in an accelerated recovery of peripheral CD4+ and CD8+ cell numbers in the spleen and lymph node. The numbers of CD8+ cells were increased by twofold over normal levels in cyclophosphamide-treated mice receiving IL-7. Myeloid recovery was determined in cyclophosphamide treated mice by assessing the numbers of CFU-granulocyte-macrophage and Mac 1+ cells. There was no significant difference in myeloid recovery between cyclophosphamide-treated mice receiving IL-7 or control protein. These results suggest that administration of IL-7 after chemical-induced lymphopenia may have therapeutic benefits in shortening the period required to achieve normal lymphoid cellularity.

Animals↗

PubMed1991

Interleukin 4 alone or in combination with interleukin 1 stimulates 3T3 fibroblasts to produce colony-stimulating factors.

Colony-stimulating activity (CSA) can be produced by fibroblasts when stimulated by interleukin 1 (IL-1). We show that like IL-1, interleukin 4 (IL-4) can stimulate 3T3 fibroblasts to produce CSA. Biological and molecular analyses show that a significant portion of the CSA is colony-stimulating factor 1 (CSF-1) and granulocyte colony-stimulating factor (G-CSF). CSF-1 production in cells stimulated with a combination of both IL-1 and IL-4 was greater than that observed when cells were stimulated with either cytokine alone. However, the data show a synergistic induction of the expression of high levels of G-CSF mRNA and protein in cells incubated in the presence of both IL-1 and IL-4. The concentration of G-CSF in supernatants from cells stimulated with both IL-1 and IL-4 was at least tenfold higher than that measured in supernatants harvested from cells stimulated with either IL-1 or IL-4 alone. Previous investigations have shown that IL-4 had direct effects on hematopoietic progenitor cell growth. The studies described herein indicate that IL-4 is also involved in the regulation of hematopoiesis in an indirect manner, that is, by playing a role in the regulation of hematopoietic growth factor production.

Animals↗

PubMed1990

Identification of a ligand for the c-kit proto-oncogene.

We report the purification and N-terminal amino acid sequence of a novel mast cell growth factor, termed MGF, from the supernatants of a murine stromal cell line. A panel of interleukin 3-dependent cell lines were screened for responsiveness to partially purified MGF in [3H]thymidine incorporation assays; proliferative stimulation of these cells in response to MGF correlated with expression of mRNA for the c-kit protooncogene. MGF was shown to be a ligand for c-kit by cross-linking 125I-labeled MGF to c-kit-expressing cells with subsequent immunoprecipitation of the complex with antiserum specific for the C-terminus of c-kit. This establishes MGF as a ligand for the c-kit protein.

Amino Acid Sequence↗

PubMed1990

T-cell growth factor P40 promotes the proliferation of myeloid cell lines and enhances erythroid burst formation by normal murine bone marrow cells in vitro.

T-cell growth factor P40 was examined for possible effects on murine interleukin-3 (IL-3)-dependent myeloid cell lines and freshly isolated murine bone marrow cells. The results showed that P40 stimulated the proliferation of some IL-3-dependent myeloid cell lines of both early myeloid and mast cell phenotype and synergized with IL-3. P40 did not promote proliferation of fresh bone marrow cells, bone marrow enriched for early myeloid cells by 5-fluorouracil treatment, or bone marrow derived mast cells as assessed in 3H-TdR incorporation assays. P40 did not influence the growth of murine colony-forming unit granulocyte-macrophage in agar cultures, either alone or in the presence of optimal or sub-optimal concentrations of CSF-1, GM-colony-stimulating factor, or IL-3. P40 did potentiate burst-forming unit-erythroid (BFU-E) formation in the presence of erythropoietin; however, this was dependent on the cell plating density, suggesting an indirect stimulation of BFU-E by P40. The indirect nature of P40 action on BFU-E was further demonstrated in cell separation experiments and indicated that the effect was mediated by T cells. These data expand the repertoire of cells that P40 influences.

Animals↗

PubMed1990

Clonal growth of murine pre-B colony-forming cells and their targeted infection by a retroviral vector: dependence on interleukin-7.

The cDNA for interleukin-7 (IL-7) was recently isolated from a stromal cell line derived from a long-term B-lymphoid culture. We report that purified recombinant murine IL-7 can promote the clonal growth in semi-solid culture of a subpopulation of cells expressing the B220 surface antigen from normal murine bone marrow. These colony-forming cells (CFC-Pre-B) give rise to colonies of 20 to 1,000 cells after 7 days in culture. Morphologic examination of cells within the colonies showed a characteristic lymphoid morphology, and histochemical examination demonstrated an absence of markers associated with granulocyte, macrophage, eosinophil, or megakaryocyte differentiation, as well as an absence of hemoglobinization (indicative or erythroid differentiation). IL-7 was found to specifically enhance the infection of CFC-Pre-B but not CFU-GM when the cytokine was present during a 48-hour co-cultivation period between irradiated, retrovirus-producing psi 2 clones and normal mouse bone marrow cells. In contrast, IL-3 enhanced the infection of CFU-GM but not CFC-Pre-B. Thymidine suiciding studies suggest that this targeted infection is due to specific induction of cycling of CFC-Pre-B by IL-7 and CFU-GM by IL-3. These data demonstrate that IL-7 can target retroviral infection into a specific subpopulation of early B-lymphoid cells (CFC-Pre-B), and that IL-7 cannot directly promote the in vitro clonal growth of myeloid committed progenitor cells (ie, CFU-GM).

Animals↗

PubMed1990

Role for cyclic AMP in the postreceptor control of cytokine-stimulated stromal cell growth factor production.

We examined the role of augmented formation of intracellular cyclic AMP (cAMP) in the mediation of stromal cell growth factor production that occurs constitutively or upon cytokine stimulation. Clonal murine marrow adherent cell lines were stimulated under serum-free conditions by interleukin-1 (IL-1) or lipopolysaccharide (LPS) and one (+/+ -1.LDA11) was found to produce low quantities of granulocyte macrophage colony-stimulating factor (GM-CSF). GM-CSF identity was confirmed by the ability of supernatants from stromal cells to promote proliferation of the factor-dependent cell line FDC-P1, neutralization of this activity by antiserum to GM-CSF, and by Northern blot analysis. However, optimal concentrations of IL-1 and tumor necrosis factor-alpha (TNF-alpha), in combination, led to synergistic (greater than 5-fold higher quantity) GM-CSF production compared with either stimulus alone in the +/+ -1. LDA11 cell line, capable of GM-CSF production after only single stimulation with IL-1 or LPS. In addition, synergistic stimulation by IL-1 and TNF-alpha led to equivalent high amounts of GM-CSF in another cell line incapable of GM-CSF production after induction with only IL-1 or LPS. Any of several means to raise intracellular cAMP levels, including addition of 8-bromo-cyclic AMP (8Br cAMP) (0.25-1mM), pertussis toxin (20-100 ng/ml), or addition of prostaglandin E1 (PGE1) (1 microM), failed to stimulate GM-CSF production alone and strongly inhibited GM-CSF production in stromal cells stimulated by IL-1, LPS, or the synergistic combination of IL-1 and TNF-alpha. In addition, PGE1 and pertussis intoxication were agonists of adenylate cyclase in membranes of marrow adherent cells, whereas IL-1 and LPS were not. The role for regulators of intracellular cAMP was specific because any of the cAMP agonists alone, or in the presence of cytokine stimulators of stromal cells, strongly enhanced IL-6 production, an event known to be cAMP-responsive. Thus, acute formation of intracellular cAMP is a negative regulator of stromal cell GM-CSF production mediated by cytokines, but positively regulates IL-6 production and may be an important determinant of cytokine-directed marrow microenvironmental function. These findings on the requirement for augmentation versus inhibition of cytokine-mediated production of hemopoietic growth factors might be applied to an analysis of marrow stromal cell heterogeneity.

Adenylate Cyclase Toxin↗

PubMed1990

A novel mast cell growth factor (MCGF-3) produced by marrow-adherent cells that synergizes with interleukin 3 and interleukin 4.

A clonal marrow-adherent stromal cell line, +/+-1 LDA11, was derived and found to produce hemopoietic stimulatory activity for an interleukin 3 (IL-3)-dependent mast cell line, NFS/N1. This factor-dependent mast cell line displayed restricted growth factor responsiveness to only IL-3, interleukin 4 (IL-4), and the stromal cell-produced factor. The factor produced by stromal cells was distinguished from IL-3 and IL-4 and was characterized biochemically. This factor appears to be a novel mast cell growth factor (MCGF-3) capable of synergizing with IL-3 and IL-4. It may have broader reactivity in hemopoiesis than simply IL-3-dependent mast cells, and it may prove relevant to stromal cell-mediated hemopoiesis.

Animals↗

PubMed1989

Human marrow stromal cells: response to interleukin-6 (IL-6) and control of IL-6 expression.

Production of interleukin-6 (IL-6) by marrow stromal cells from human long-term marrow cultures and from stromal cells transformed with simian virus 40 was examined. As with other cultured mesenchymal cells, unstimulated stromal cells produced undetectable amounts of IL-6 mRNA when assayed by Northern blots. However, within 30 minutes after exposure of transformed marrow stromal cells to the inflammatory mediators, recombinant human interleukin-1 alpha (IL-1 alpha) or recombinant human tumor necrosis factor alpha (TNF alpha), significant increases in IL-6 expression were observed. The time course of IL-6 mRNA upregulation in transformed marrow stromal cells with IL-1 alpha and TNF alpha differed: The maximal response to TNF alpha was observed at 30 minutes whereas that to IL-1 alpha occurred at 8 hours. Although IL-6 at a concentration of 500 U/mL was inhibitory to adherent transformed marrow stromal cell proliferation, a concentration-dependent stimulation of anchorage-independent colony growth was observed when the cells were plated in semisolid medium with IL-6. The stromal cell colony-stimulating effect of IL-6 was abrogated by a neutralizing antibody to IL-6. Moreover, the heteroserum with anti-IL-6 activity and two anti-IL-6 monoclonal antibodies partially blocked autonomous and IL-1 alpha-induced colony formation, suggesting that colony formation by transformed marrow stromal cells may require IL-6. Clonal-transformed stromal cell lines were derived from the anchorage-independent stromal cell colonies. Both IL-6 mRNA and protein were constitutively produced at high levels. The addition of IL-6 to either long-term marrow culture adherent cells or transformed marrow stromal cells downregulated the expression of collagen I, a major stromal cell matrix protein. Thus, IL-6 affects proliferation of stromal cells and influences their production of extracellular matrix, suggesting that IL-6 may have indirect as well as direct influences on hematopoietic cell proliferation.

Blotting, Northern↗

PubMed1989

Interleukin-1 is identical to hemopoietin-1: studies on its therapeutic effects on myelopoiesis and lymphopoiesis.

Conditioned medium from the human tumor cell line HBT 5637 possesses a unique hematopoietic activity, originally termed hemopoietin-1. Hemopoietin-1 alone does not stimulate bone marrow colony formation or proliferative responses in vitro, but rather potentiates responses to other hematopoietic growth factors, such as CSF-1 and GM-CSF. In studies designed to characterize the molecular nature of this factor, it was found by molecular, biochemical biological and serological criteria that all the hemopoietin-1 like activity could be attributed to IL-1 alpha. The therapeutic potential of IL-1 was then tested in a system where myelopoiesis is depressed by whole body irradiation. After 750 R irradiation, mice were administered IL-1 twice daily for the duration of the experiment. Mice which received IL-1 treatment had an accelerated recovery of marrow colony forming capacity which was also reflected by significantly higher blood neutrophil levels as compared to control irradiated mice. IL-1 treated irradiated mice also had a significant increase in resistance to bacterial challenge 14 days post irradiation. Thus, IL-1 treatment was effective in augmenting myelopoiesis following sublethal whole body irradiation. The effects of the IL-1 treatment on the recovery of lymphocyte numbers was also assessed. Here the IL-1 treated irradiated mice had fewer lymphocytes and depressed mitogen responses by spleen cells. Indeed the thymus of the IL-1 treated irradiated mice remained chronically hypoplastic for the duration of the experiment. Although IL-1 treatment increased myeloid progenitors in the bone marrow, it caused a decrease in the frequency of pre-B cells. Thus, IL-1 administration is an effective treatment for accelerating myeloid recovery following the cytoreductive effects of irradiation, but the myelopoietic augmentation may be at the expense of lymphoid recovery.

Animals↗

PubMed1989

Interleukin 1 plus interleukin 3 plus colony-stimulating factor 1 are essential for clonal proliferation of primitive myeloid bone marrow cells.

The clonal growth in nutrient agar at low cell densities of high-proliferative potential colony-forming cells (HPP-CFC) of bone marrow obtained from mice treated 2 days earlier with 5-fluorouracil (FU) (FU2dBM) has been shown to require a combination of three growth factors, interleukin 1 (IL-1), interleukin 3 (IL-3), and macrophage colony-stimulating factor (CSF-1). These HPP-CFC have been enriched 140-fold from FU2dBM by fluorescence-activated cell sorting of 7/4-, B220-, and L3T4-negative cells. The mean of the plating efficiencies of these enriched populations was 4.4% and no growth was observed when the factors were used singly. Similarly, enrichments of 16-fold were obtained from FU2dBM using immunomagnetic Dynabeads with anti-7/4 plus anti-B220 (meaning plating efficiency 0.5%). The further additions of human granulocyte CSF or mouse granulocyte-macrophage CSF or both to IL-1 plus IL-3 plus CSF-1 did not increase HPP-CFC colony formation, but both augmented the small colony formation with IL-1 plus IL-3, IL-3 plus CSF-1, or IL-1 plus CSF-1.

Animals↗

PubMed1988

Stimulation of B-cell progenitors by cloned murine interleukin-7.

The events involved in the commitment and development of lymphoid lineage cells are poorly understood. We have used a recently described long-term culture system to establish a bioassay that can detect a novel growth factor capable of stimulating the proliferation of lymphoid progenitors. Using direct expression in mammalian cells we have isolated a complementary DNA clone encoding this novel haematopoietic growth factor, designated interleukin-7.

Amino Acid Sequence↗

PubMed1988

B cell precursor growth-promoting activity. Purification and characterization of a growth factor active on lymphocyte precursors.

We have used a biological assay system we developed to biochemically purify a previously uncharacterized murine lymphopoietic growth factor designated lymphopoietin 1 (LP-1). This factor is capable of stimulating the proliferation and extended maintenance of precursor cells of the B lineage. A stromal cell line producing LP-1 was established after transfection of primary stromal cultures with a plasmid encoding the transforming genes of SV40. This factor was purified to a single 25-kD species from the culture supernatant of an adherent stromal cell line. This material acts on immature lymphocytes, it binds to specific receptors on cells, and is distinct from previously described hematopoietic factors. LP-1 has been purified some 10(7)-fold with an overall recovery of 35%. The purified protein exhibits a specific activity of approximately 4 X 10(6) U/micrograms of protein and is active at a half-maximal concentration of 10(-13) M.

Animals↗

PubMed1988

Propagation and characterization of human blood basophils.

Basophils were isolated and propagated in large numbers from the blood of patients with chronic myelogenous leukemia. Propagation over 4-6 weeks of culture was dependent upon a growth factor(s) other than interleukin-2 obtained from a lectin-stimulated clone of the Jurkat cell line. Evidence that these basophils were dividing during culture included an increase in both the number of basophils and the histamine content of the cultures over time, as well as ultrastructural studies that demonstrated basophil cell division. The cells also had the capacity to be stimulated in an IgE-dependent manner characteristic of basophils. Cultured basophils passively sensitized with IgE underwent noncytotoxic degranulation after stimulation with specific antigen. Antigen-stimulated basophils released histamine, leukotrienes B4 and C4 and other 5-lipoxygenase products of arachidonic acid metabolism. Culture models such as this may permit the propagation and purification of sufficient numbers of basophils to allow biochemical and immunological analyses of basophil physiology.

Arachidonic Acid↗

PubMed1987

Phosphorylation of the CD8 antigen on cytotoxic human T cells in response to phorbol myristate acetate or antigen-presenting B cells.

We have used the monoclonal antibody OKT8 to demonstrate that the cluster designation (CD)8 antigen on cytotoxic human T cells undergoes a previously unreported protein modification. Immunoprecipitation of CD8 with OKT8 from a CD8+ and CD4+ T cell line prelabeled with [32P]phosphate demonstrates that CD8 can be constitutively labeled with phosphate. CD8 undergoes rapid and intense phosphorylation in serine upon addition of phorbol myristate acetate to the cells. CD8 phosphorylation is induced upon addition of heterologous, Epstein-Barr virus-transformed B cells, which cause proliferation and are target cells for a cytotoxic CD8+CD4+ T cell line and a CD8+CD4- T cell clone. Phosphorylation induced by targets is dose-dependent, rapid, and followed by a fast dephosphorylation. Epstein-Barr virus-transformed B cells that do not induce proliferation of and are not targets for the CD8+CD4+ line and the CD8+CD4- clone do not induce CD8 phosphorylation. Cloned CD8+CD4- cells that proliferate in response to target cells, but lyse them only in the presence of lectin do not undergo target cell-induced CD8 phosphorylation. These data suggest that induction of CD8 phosphorylation is antigen-specific and is coincident with the cytotoxic response. Finally, preincubation of effector and target cells with an antibody to a monomorphic determinant of major histocompatibility complex class I antigens reduces target-induced CD8 phosphorylation to a greater extent than antibody to a major histocompatibility complex class II subregion (DR) monomorphic determinant, reinforcing the notion that major histocompatibility complex class I antigens interact with CD8+ cells.

Antibodies, Monoclonal↗

PubMed1987

Interleukin 1 regulates hematopoietic activity, a role previously ascribed to hemopoietin 1.

A murine in vitro assay was developed to measure potentiation of a proliferative response to suboptimal concentrations of the hematopoietic regulatory molecule granulocyte/macrophage colony-stimulating factor by an immature bone marrow population. The assay, designated the 5-fluorouracil bone marrow proliferation assay, was used to characterize potentiating activity in serum-free culture supernatants of the human tumor cell line HBT 5637. Molecular and biochemical analyses indicated that the HBT 5637-derived potentiating activity could be attributed to interleukin 1 alpha. Serologic analysis using a monoclonal antibody against purified recombinant interleukin 1 alpha proved conclusively that the potentiating activity in HBT 5637 serum-free supernatants is due to interleukin 1 alpha. From these data, the activity of interleukin 1 alpha seems to be the same synergistic activity formerly ascribed to hemopoietin 1.

Animals↗

PubMed1987

Expression and purification of native human granulocyte-macrophage colony-stimulating factor from an Escherichia coli secretion vector.

The human granulocyte-macrophage colony stimulating factor (GM-CSF) was expressed and purified from a high-level Escherichia coli secretion vector. A cDNA fragment encoding mature GM-CSF was fused with the aid of a synthetic oligonucleotide to the E. coli outer membrane signal peptide (ompA) of the secretion expression vector pIN-III-ompA3. The primary construction, designated pLB5001, is under transcriptional control of the tandem lipoprotein promoter (lppP) lactose promoter-operator (lacPO), and is regulated by the lactose repressor. Upon induction, a polypeptide of MW = 14,600 was produced which had GM-CSF activity in a human bone marrow colony assay. The linker sequence between the ompA signal peptide and the amino terminus of the mature GM-CSF was removed by oligonucleotide-directed site-specific mutagenesis to produce GM-CSF with an authentic amino terminus. The resulting construct, designated pLB5001-4, expressed authentic GM-CSF with a specific activity similar to that observed for the pLB5001 specified GM-CSF. Both versions of GM-CSF were associated with the membrane fraction after osmotic shock, and were purified to homogeneity by DEAE-Sephacel chromatography, followed by reversed-phase HPLC. Amino acid sequencing from the amino terminus of the purified GM-CSF established that the ompA signal peptide was cleaved at its normal processing site in both cases.

Amino Acid Sequence↗

PubMed1986

Rapid phosphorylation and modulation of the T4 antigen on cloned helper T cells induced by phorbol myristate acetate or antigen.

A cell surface protein known as T4 (CD4, Leu3), Mr = 55,000, is expressed on the subset of human T lymphocytes which provides helper function for B cell and cytotoxic T cell activities. We show that T4 is constitutively phosphorylated and that phorbol myristate acetate (PMA) induces a rapid serine phosphorylation which is followed by a fast dephosphorylation. Within 5 min after PMA treatment, there is a 24% reduction of T4 on the cell surface, by 4 h the loss is nearly complete, and by 20 h T4 is re-expressed. Addition of antigen to a T4+ antigen-reactive T cell clone induces both phosphorylation and dephosphorylation with kinetics similar to that described for PMA. Antigen also causes reduction of cell surface T4, although to a lesser degree than stimulation with PMA. The rapid phosphorylation/dephosphorylation of T4 as well as its movement from the cell surface suggest that T4 functions as a receptor for an unknown ligand.

Amino Acid Sequence↗

PubMed1986

Purification to homogeneity of a human hematopoietic growth factor that stimulates the growth of a murine interleukin 3-dependent cell line.

A human lymphokine derived from the 5637 bladder carcinoma has been purified to homogeneity by using sequential reverse-phase high pressure liquid chromatography. A high recovery of biological activity is obtained by using this purification. The NH2-terminal amino acid sequence shows no homology to human interleukin 1 (IL 1), human IL 2, murine IL 3, or human granulocyte-macrophage colony-stimulating factor. The growth-promoting properties of the 5637-derived factor can be rapidly assayed by using the murine IL 3-dependent 32D c1-23 cell line. The amino acid sequence described is identical to that recently described for a human granulocyte colony-stimulating factor.

Animals↗