Biomedical subjects

D Rennick

Publications and source records attributed to D Rennick.

43 records · Page 3Linked to original sources

PubMed1986

Regulation of expression of the interleukin-2 receptor on hematopoietic cells by interleukin-3.

Remarkable similarities in the intracellular and genetic events occur when lymphoid and hematopoietic cells are exposed to their specific growth factors. The interleukin-2 (IL-2) receptor, whose cell-surface expression is an absolute requirement for the growth and differentiation of lymphoid cells, was detected on various nonlymphoid hematopoietic cell types in this study. Cell lines consisting either of granulocyte-macrophage precursors or mast cells, which are dependent on interleukin-3 (IL-3) for their growth, expressed high levels of the IL-2 receptor on their surface. Analysis of the binding characteristics of these receptors with 125I-labeled recombinant IL-2 revealed that only receptors with low affinity for IL-2 were present on these cells. Addition of purified recombinant IL-3 to these cell lines led to an increase in IL-2 receptor gene expression within 1 hour in isolated nuclei. This IL-3--induced increase in the number of IL-2 receptors on the cell surface is maximal within 24 hours. Addition of 10,000 units of IL-2 to these cells had no apparent effect on their growth or differentiation. The presence of the receptor with only low affinity for IL-2 on hematopoietic cells and the regulation by IL-3 suggest that this receptor is involved in some important metabolic event in hematopoiesis.

Animals↗

PubMed1986

Isolation and characterization of a mouse interleukin cDNA clone that expresses B-cell stimulatory factor 1 activities and T-cell- and mast-cell-stimulating activities.

A cDNA sequence coding for a unique mouse interleukin that expresses B-cell-, T-cell, and mast-cell-stimulating activities has been isolated from a mouse helper T-cell cDNA library. The library, constructed in the pcD expression vector, was screened by transfecting COS monkey cells with DNA pools to express the products encoded by full-length cDNA inserts. By assaying the transfected cell supernatants, we identified clones encoding a factor that stimulates T-cell and mast cell lines. This factor also induces Ia expression on resting B cells and enhances IgG1 and IgE production by B cells, two properties of B-cell-stimulatory factor 1. The DNA sequence codes for a polypeptide of 140 amino acid residues including a putative signal peptide. These results demonstrate that a single cDNA clone distinct from interleukin 2 and interleukin 3 encodes a polypeptide with multiple biological activities.

Amino Acid Sequence↗

PubMed1986

Multilineage hematopoietic growth factor interleukin 3 and direct activators of protein kinase C stimulate phosphorylation of common substrates.

In order to investigate early signal transduction events in myeloid cells, the phosphosubstrates of an interleukin 3 (IL 3)-dependent cell line, FDC-P1, have been analyzed. Using synthetic diacylglycerol as a direct activator of the unique calcium-phospholipid-dependent phosphotransferase protein kinase C (PK-C) and genetically engineered homogeneous IL 3, we have demonstrated a common element to signal transduction events associated with these stimulants. One novel substrate, p68 (68,000 kd), was rapidly phosphorylated in either IL 3- or diacylglycerol-stimulated cells. The phosphorylation of p68 was dose-dependent, with both the physiological ligand and diacylglycerol inducing the same maximal level of phosphorylation. Phosphorylation of p68 occurred in a time-dependent manner analogous to previously described kinetics of PK-C subcellular redistribution in the FDC-P1 cell line. The p68 substrate was also phosphorylated in a cell-free system under conditions designed to activate PK-C. Phosphoamino acid analysis demonstrated that the p68 molecule phosphorylated in intact cells as well as in a calcium-phospho-lipid-dependent cell-free system was phosphorylated on threonine residues, not tyrosine. These data support the hypothesis that the activation of PK-C that occurs after IL 3-receptor interaction which leads to the rapid phosphorylation of cellular proteins is an important element of the signal transduction mechanism in FDC-P1 cells. We propose that phosphorylation of the p68 molecule is a physiochemical marker for the activation of PK-C in myeloid cells, in response to the growth-promoting physiological ligand.

Animals↗

PubMed1985

Use of a cDNA expression vector for isolation of mouse interleukin 2 cDNA clones: expression of T-cell growth-factor activity after transfection of monkey cells.

A cDNA sequence coding for mouse interleukin 2 (IL-2) has been cloned from a cDNA library prepared from mRNA derived from a concanavalin A-activated mouse T-cell clone. The library was constructed by using the pcD vector system, which permits the expression of cDNA inserts in mammalian cells. Screening of the library was performed by transfecting COS-7 monkey cells with pools of cDNA clones in order to express the products encoded by full-length cDNA inserts. By assaying the supernatant fluid, IL-2 cDNA clones that express T-cell growth-factor (TCGF) activity were identified. The DNA sequence codes for a polypeptide of 169 amino acid residues including a putative signal peptide. The mouse IL-2 amino acid sequence deduced from the nucleotide sequence of its cDNA shares extensive homology with the human IL-2 amino acid sequence reported previously. These results demonstrate that identification of full-length cDNA clones for many lymphokines may be achieved entirely on the basis of detection of the functional polypeptides in mammalian cells.

Amino Acid Sequence↗

PubMed1985

Isolation of cDNA for a human granulocyte-macrophage colony-stimulating factor by functional expression in mammalian cells.

A cDNA sequence coding for a human granulocyte-macrophage colony-stimulating factor has been isolated from cDNA libraries prepared from mRNA derived from concanavalin A-activated human T-cell clones. The libraries constructed in the pcD vector system were screened by transfecting COS-7 monkey cells with DNA pools to express the products encoded by full-length cDNA inserts. By assaying the cell supernatants, we identified clones encoding a factor that stimulates the formation of granulocyte and macrophage colonies from human progenitor cells. These results demonstrate that identification of full-length cDNAs for many colony-stimulating factors may be achieved entirely on the basis of detecting the functional polypeptide produced in mammalian cells.

Amino Acid Sequence↗

PubMed1984

Isolation and characterization of a mouse cDNA clone that expresses mast-cell growth-factor activity in monkey cells.

A cDNA sequence coding for mouse mast-cell growth-factor (MCGF) has been cloned from a cDNA library prepared from mRNA derived from a concanavalin A-activated mouse T-cell clone. Cloning was achieved using the pcD vector that permits expression of cDNA inserts in mammalian cells. The DNA sequence codes for a polypeptide of 166 amino acid residues including a putative signal peptide. The supernatant fluid obtained after transfection of COS-7 monkey cells with the pcD-MCGF plasmid had mouse MCGF activity. The MCGF amino acid sequence between amino acids 33 and 41, deduced from the nucleotide sequence of its cDNA, is identical to the NH2-terminal sequence of the mouse lymphokine, interleukin 3, suggesting that MCGF is related to interleukin 3.

Amino Acid Sequence↗

PubMed1977

Immunity to lymphoid tumors in syngeneic mice by immunization with mitomycin C-treated cells.

Immunization of mice with syngeneic mitomycin C-treated lymphoid tumor cells (EL-4 and S49A) conferred a high degree of immunity to transplantation with viable tumor cells in syngeneic animals. The development of this immunity was paralleled by the development of specific cell-mediated cytotoxicity; no anti-tumor antibodies could be detected in the immunized animals. In contrast to the high immunoprophylactic capacity of mitomycin C-treated cells, attempts to utilize these cells for immunotherapy were unsuccessful. Preliminary experiments did not reveal antigenic differences between mitomycin C-treated and untreated tumor cells.

Animals↗