Showing papers by "Charles A. Dinarello published in 1985"

Pretranslational modulation of acute phase hepatic protein synthesis by murine recombinant interleukin 1 (IL-1) and purified human IL-1.

Abstract: During the acute phase response to tissue injury or inflammation, the concentration of several plasma proteins change. Previous work (29-34) suggested a role for interleukin 1 (IL-1) in the acute phase response. The availability of recombinant-generated mouse IL-1 prompted a study designed to directly test the function of IL-1 and its mechanism of action on hepatic synthesis of two positive acute phase proteins (serum amyloid A [SAA] and complement factor B), and a negative acute phase reactant (albumin). Intravenous injection of purified recombinant-generated murine-IL-1 into C3H/HeJ endotoxin-resistant mice induced a dose-dependent increase in SAA-specific hepatic messenger RNA (mRNA), and an increase in SAA plasma protein concentration. In primary murine hepatocyte cultures, both the recombinant IL-1 and highly purified human IL-1 induced a dose- and time-dependent, reversible increase in expression of the SAA and factor B genes, and a decrease in albumin gene expression. This regulation is pretranslational, since the kinetics and direction of change in specific mRNA for SAA, factor B, and albumin correspond to the changes in synthesis of the respective proteins. Moreover, the effect of IL-1 was specific, since actin gene expression was unaffected, and the IL-1 response was inhibited by antibody specific for IL-1. These data provide direct evidence that a single mediator, IL-1, can effect the positive and negative changes in specific hepatic gene expression characteristic of the acute phase response.

An update on human interleukin-1: from molecular biology to clinical relevance

Abstract: Interleukin-1 (IL-1) represents a family of polypeptides with a wide range of biological activities. At least two dissimilar gene products have been cloned; there are probably more. The human IL-1 family plays an important role in the pathogenesis of many diseases and functions as a key mediator of the host response to various infectious, inflammatory, and immunologic challenges. Recombinant mouse (pI 5) and recombinant human (pI 7) IL-1's are being used to confirm the multiple biological properties of IL-1's but considerable investigation is required before the specific activities (biological units per milligram of protein) are established for each human IL-1 form. Some IL-1 biological activities such as the induction of hepatic acute-phase protein synthesis have been demonstrated in invertebrates predating the evolution of lymphocytes. IL-1 is highly inflammatory and increases the concentration of metabolites of arachidonic acid, most notably prostaglandin E2, in brain, muscle, chondrocytes, and synovial fibroblasts. The synthesis of leukotrienes also is involved in the mechanism of its action on certain tissues. The cloning and expression of human IL-1 genes will expand our understanding of IL-1 in various diseases through improved detection systems and the use of cDNA probes; the development of IL-1 antagonists, as well as the use of IL-1 as an immunomodulator, is presently being considered.

Increased plasma interleukin-1 activity in women after ovulation

Abstract: The polypeptide interleukin-1 mediates many host responses to infection and inflammation. A method was developed for studying interleukin-1 levels in human plasma from febrile patients. Interleukin-1 activity was also consistently found in plasma samples from women in the luteal phase of their menstrual cycle. This activity was neutralized by a specific antiserum to human interleukin-1 and was low in plasma from healthy men and preovulatory women. Thus interleukin-1 appears to have a role in normal physiological conditions as well as in disease states.

The events of primary T cell activation can be staged by use of Sepharose-bound anti-T3 (64.1) monoclonal antibody and purified interleukin 1.

Abstract: A mitogenic anti-CD3 ("T3") monoclonal antibody (64.1), that stimulates polyclonal T cell activation by a mechanism believed to be similar to antigen via binding to the T cell receptor complex, was utilized in soluble (SOL) and Sepharose-bound (SEPH) forms to dissect the role of accessory cells (AC) and interleukin 1 (IL 1) in supporting T cell activation. The T cell activation pathway was dissected into "early" events including expression of interleukin 2 receptors (IL 2R), increased RNA content, IL 2 release, and "late" (DNA synthesis) events. Unseparated peripheral blood mononuclear cells progressed through all stages of activation when stimulated by either form of 64.1. Stringent AC depletion by plastic adherence, nylon wool adherence, and L-leucine methyl ester (selectively lyses AC) prevented early and late T cell responses to either form of 64.1. The addition of highly purified IL 1 replenished both early and late T cell responses to SEPH-64.1 but not to SOL-64.1. Although SOL-64.1 stimulation of purified T cells induced modulation of the CD3 complex, only SEPH-64.1 induced IL 1 responsiveness, and exogenous IL 1 was then able to support synthesis of RNA, secretion of IL 2, expression of IL 2R, and ultimately, DNA synthesis. Therefore, the stages of early T cell activation owing to stimulation of the CD3-T cell receptor complex and IL 1 responsiveness have been dissected.

Differential effects of human interleukin-1 on growth of human fibroblasts and vascular smooth muscle cells.

Abstract: Monocyte products probably play a role in the initiation of smooth muscle cell proliferation in the arterial wall early in atherogenesis. Several groups have described mitogenic activity for arterial smooth muscle cells that is elaborated by mononuclear phagocytes (macrophage-derived growth factor). However, the biochemical nature of this mitogenic activity is unknown. Interleukin-1 (IL-1) is a well-characterized monocyte product that activates the growth of mitogen-stimulated lymphocytes and promotes the growth of fibroblasts. We tested whether IL-1 also affects the growth of arterial smooth muscle cells and might account for some of the mitogenic activity produced by activated monocytes. Highly purified human IL-1 did stimulate the growth of human fibroblasts of either adult or fetal origin. However, under identical conditions, IL-1 lacked significant mitogenic effects on human, bovine, rabbit, or canine arterial smooth muscle cells. This mediator also failed to stimulate the growth of cultured human or bovine vascular endothelial cells, another cell type that may respond to macrophage-derived growth factor. Interleukin-1 did not render smooth muscle cells competent to divide in the presence of plasma factors such as insulin (10(-6) M), or when growth of muscle cells was limited by incubation in a low (2%) concentration of serum. This monokine also failed to increase the mitogenic effect of purified platelet-derived growth factor on arterial smooth muscle cells incubated in serum-free medium. Thus, cultured human arterial smooth muscle cells differ from fibroblasts and lymphocytes in their response to human IL-1.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of interleukin 1 (IL 1) in tumor-NK cell interactions: correction of defective NK cell activity in cancer patients by treating target cells with IL 1.

Abstract: This study examined the importance of interleukin 1 (IL 1) in the large granular lymphocyte (LGL)-target cell interaction. K562 target cells when treated with highly purified human IL 1 for 1 hr bound greater numbers of LGL than untreated cells. LGL from patients with hepatocellular carcinoma (HCC) that bound few untreated K562 cells, attached to considerably increased numbers of IL 1-treated target cells. Cytotoxicity of LGL against target cells could similarly be increased by pulsing the latter cells with IL 1, and defective cytotoxicity of LGL from HCC patients could be corrected by treating the target K562 cells with IL 1. Lysis of PLC/PRF/5 cells, Yac-1 cells, and normal skin fibroblasts could also be increased by treatment with IL 1 for 1 hr. The enhanced binding and cytotoxicity of IL 1-treated target cells was only observed when the latter cells were preincubated with IL 1 at 37 degrees C, and was not evident at 4 degrees C. Furthermore, the IL 1-mediated effect could be abolished by treating the target cells with cycloheximide before the IL 1 pulse, or by adding rabbit anti-human IL 1 together with the IL 1. These results indicate that IL 1 affects a variety of target cells and increases their ability to bind and be lysed by enriched LGL. They demonstrate, furthermore, that defective natural cytotoxicity by the LGL of patients with advanced malignant disease can be corrected in vitro by treating the target cells with IL 1.

Human and murine interleukin 1 possess sequence and structural similarities.

Abstract: The molecular cloning and sequence analysis for human and murine interleukin 1 precursor have recently been described. Comparison of the amino acid sequences resulting from these data can be used to aid in the identification of conserved regions essential to biological activity. We report results which confirm the relationship between these two molecules and suggest that specific regions may be essential for activity. Amino terminal sequence analysis of a 19,000 Mr biologically active IL-1 isolated from stimulated human monocytes reveals a sequence which is in good agreement with that inferred from the human cDNA and, furthermore, locates the processed amino terminus at a site similar to that described for the murine sequence.

Truncated protein of interleukin-1

Abstract: The subject invention concerns truncated human IL-1 cDNA sequences which encode biologically-active novel human IL-1 proteins. These truncated human IL-1 cDNA sequences can be obtained by genetic engineering procedures using a clone of human IL-1 cDNA, having the accession number NRRL B-15770, as a starting material. The truncated human IL-1 cDNA sequences of the subject invention are contained in specified plasmids whose constructions are described in detail. Biologically-active human IL-1 proteins are useful to induce the production of IL-2 by activated T-cells. They also act on B-cells and NK-cells.

Human il-1 cDNA sequences encoding biologically-active human il-1 proteins

Abstract: The subject invention concerns truncated human Il-1 cDNA sequences which encode biologically-active novel human IL-1 proteins. These truncated human IL-1 cDNA sequences can be obtained by genetic engineering procedures using a clone of human IL-1 cDNA, having the accession number NRRL B-15770, as a starting material. The truncated human IL-1 cDNA sequences of the subject invention are contained in specified plasmids whose constructions are described in detail. Biologically-active human IL-1 proteins are useful to induce the production of IL-2 by activated T-cells. They also act on B-cells and NK-cells.

Parasite-monocyte interactions in human leishmaniasis: production of interleukin-1 in vitro

Abstract: Leishmania are obligate intracellular protozoa that parasitize mononuclear phagocytes. Because mononuclear phagocytes are also the primary source of leukocytic pyrogen and of lymphocyte-activating factor, both considered properties of interleukin-1 (IL-1), we investigated in vitro production of leukocytic pyrogen and of lymphocyte-activating factor from human monocytes infected with Leishmania tropica. Despite parasitization of 95% of cells, 24- and 48-hr culture supernatants and cell lysates derived from L. tropica-infected monocytes did not contain IL-1. Leishmania that were killed by freezing or by glutaraldehyde treatment similarly did not induce monocyte production of IL-1. Of importance is the observation that human monocytes infected with L. tropica for 6 hr and then challenged with a potent IL-1 inducer (Staphylococcus epidermidis) produced significantly less IL-1 than did uninfected monocytes that were similarly challenged (P less than .001). This difference was not affected by the addition of indomethacin to the cultures. In contrast, soluble immune complexes prepared with an excess of L. tropica antigen and rabbit antibody to L. tropica induced high levels of IL-1 production from normal monocytes. Neither antigen nor antibody alone incubated with monocytes led to significant production of IL-1, however. Thus, these studies suggest that despite leishmanial adherence to, entrance into, and replication within human monocytes there is little or no stimulation of IL-1 production. This may represent a parasite evasion mechanism that retards the development of protective immune responses in leishmaniasis.

Dissimilarities between purified human interleukin-1 and recombinant human interleukin-2 in the induction of fever, brain prostaglandin, and acute-phase protein synthesis.

Abstract: The lymphokine interleukin-2 (IL-2) has been shown to enhance natural cell-mediated cytotoxicity, the generation of cytolytic T lymphocytes, and several other aspects of cellular immune function. The gene coding for human IL-2 has been cloned, and recombinant IL-2 will be available for clinical trials in patients with neoplastic, infectious, and immunodeficiency diseases. The present investigation was undertaken to determine if IL-2 was similar to interleukin-1 (IL-1) in its ability to induce fever and the acute-phase response. These studies were based on recent work with recombinant human interferon (IFN)-alpha, which is intrinsically pyrogenic and capable of producing fever by inducing the synthesis of prostaglandin E2 (PGE2). The prospect that IL-2 might exert similar physiologic effects is of critical concern since elevated temperature, PGE2, and acute-phase reactants may profoundly inhibit natural cell-mediated cytotoxicity. Our studies have shown that recombinant human IL-2 is not intrinsically pyrogenic in rabbits at doses as high as 10,000 units/kg when administered by a single intravenous injection. In contrast to IL-1, IL-2 does not stimulate cultured hypothalamus cells to synthesize PGE2, and, furthermore, IL-2 does not elevate serum C-reactive protein levels. These results predict that the administration of IL-2 to patients in doses that stimulate cellular immune function will not induce fever and other toxic side effects frequently seen in individuals receiving IFN.

Effect of protein synthesis inhibitors on leukocytic pyrogen-induced in vitro hypothalamic prostaglandin production.

Abstract: In order to study the antipyretic effect of inhibitors of protein synthesis, hypothalamic tissue was incubated in vitro under controlled conditions and the amount of prostaglandin E2 (PGE2) measured in the supernatant medium. Rabbit anterior hypothalamic tissue was incubated with purified human leukocytic pyrogen (LP) and after 60 minutes the supernatant fluid was assayed for PGE2 by radioimmunoassay. Control tissue incubated with Eagle's medium (MEM) released elevated levels of PGE2; however, the addition of polymyxin B (PmxB), a cationic antibiotic which blocks the activities of bacterial endotoxins, significantly reduced PGE2. In addition, endotoxin added to MEM induced from the brain tissue PGE2 production which could be reduced by the addition of PmxB. Thus, commercial culture media such as MEM may contain sufficient amounts of endotoxin to stimulate brain PGE2 production in vitro. Purified human LP incubated with hypothalamic tissue in the presence of PmxB induced PGE2 production in a dose-dependent fashion. This release could be reduced (p less than 0.001) by the presence of either cycloheximide or puromycin during incubation with LP. The addition of these inhibitors to unstimulated hypothalamic tissue incubations did not reduce background levels of PGE2. It is concluded that the antipyretic effect of protein synthesis inhibitors results in a specific decrease in LP-induced levels of PGE2.

Phorbol myristate acetate-protein complex mimics bioactivity of human IL-1. 1. Direct evidence that PMA temporarily enters and is released from cellular compartment during superinduction protocol.

Abstract: The K-562 cell line was treated with the superinduction protocol involving phorbol myristate acetate (PMA) for production of human interleukin 1 (IL-1). The resultant dialyzed K-562 superinduced supernatants contained potent IL-1-like activity when tested in 4 bioassays for IL-1. However, these K-562 SIS failed to induce fever in rabbits, the IL-1 like activity was not inhibited by an anti-human IL-1 antiserum in the murine thymocyte (LAF) assay, and the IL-1-like activity did not adhere to a specific immunoadsorbent column. Together with recent evidence that PMA may contaminate supernatants produced by the superinduction protocol and can mimic IL-1 bioactivity (9,10), the results of these novel methods suggested that IL-1 was not the bioactive moiety in K-562 SIS. To further examine the source of K-562 SIS IL-1-like activity, the active K-562 SIS were fractionated over Sephadex G-50, and the large molecular weight component (approximately 50,000) was found to express potent LAF activity yet remained nonpyrogenic. 3H-PMA was added to the superinduction protocol as a tracer for PMA migration. The 3H-PMA provided new and direct evidence that PMA adhered to or entered K-562 cells and adhered to plastic culture flasks during the serum free wash steps of the superinduction, and that PMA was released by K-562 cells into the serum containing supernatants during the incubation phase of the protocol. A 3H-PMA component of K-562 SIS co-migrated on gel filtration with the large molecular weight proteins which expressed LAF activity, and is a nondialyzable contaminant of superinduction supernatants. This PMA/protein complex is the main and perhaps the sole mediator of four distinct biological activities ascribed to IL-1.

Effect ofProtein Synthesis Inhibitors onLeukocytic Pyrogen-Induced inVitro Hypothalamic Prostaglandin Production

Abstract: In order to study the antipyretic effect of inhibitors of protein synthesis, hypothalamic tissue was incubated in vitro under controlled conditions and the amount of prostaglandin E2 (PGE2) measured in the supernatant medium. Rabbit anterior hypothalamic tissue was incubated with purified human leukocytic pyrogen (LP) and after 60 minutes the supernatant fluid was assayed for PGE2 by radioimmunoassay. Control tissue incubated with Eagle's medium (MEM) released elevated levels of PGE2; however, the addition of polymyxin B (PmxB), a cationic antibiotic which blocks the activities of bacterial endotoxins, significantly reduced PGE2. In addition, endotoxin added to MEM induced from the brain tissue PGE2 production which could be reduced by the addition of PmxB. Thus, commercial culture media such as MEM may contain sufficient amounts of endotoxin to stimulate brain PGE2 production in vitro. Purified human LP incubated with hypothalamic tissue in the presence of PmxB induced PGE2 production in a dose-dependent fashion. This release could be reduced (p less than 0.001) by the presence of either cycloheximide or puromycin during incubation with LP. The addition of these inhibitors to unstimulated hypothalamic tissue incubations did not reduce background levels of PGE2. It is concluded that the antipyretic effect of protein synthesis inhibitors results in a specific decrease in LP-induced levels of PGE2.