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Query: UNIPROT:P06889 (Mol)
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Growing evidence suggests that proto-oncogenes regulate central aspects of cellular physiology such as cell proliferation and differentiation. The proto-oncogenes c-fos, c-fms and c-myc are thought to be involved in these processes. In this study the human myelomonoblast line THP-1 has been used to study monocytic differentiation in response to various cytokines and the phorbolester TPA. After treatment of THP-1 cells with Tumor Necrosis Factor (TNF)-alpha, Interleukin (IL-6) and TPA the cells became adherent, lost their division potential and expressed new surface structures associated with monocytic differentiation. The expression of c-fos and c-fms transcripts was rapidly induced within 45 min by these agents and declined to undectable levels within 24 h. Exposure of THP-1 to TNF-alpha, IL-6 and TPA was associated with a rapid downregulation of c-myc expression, that returned to starting levels within 36 h. However, treatment of THP-1 with other cytokines including Granulocyte (G)-, Macrophage (M)-, Granulocyte/Macrophage (GM)-Colony Stimulating Factor (CSF), Interleukin (IL)-3 and Interleukin (IL)-4 failed to result in monocytic differentiation. These data suggest that changes in c-fms, c-myc and c-fos expression may be related to induction of monocytic differentiation and that their appearance or downregulation can be induced by certain cytokines.
Virchows Arch B Cell Pathol Incl Mol Pathol 1990
PMID:Induction of monocytic differentiation and modulation of the expression of c-fos, c-fms and c-myc protooncogenes in human monoblasts by cytokines and phorbolester. 169 41

A number of investigators have demonstrated the association of CD5+ (Ly-1/Leu-1) B cells with autoimmunity, excessive B-cell proliferation, and transformation. Previous work from our laboratory, among others, suggests that the selective advantage of this frequently autoreactive B-cell subset is to provide activation signals to conventional antigen-specific B cells. If one current hypothesis is correct then the overrepresentation of CD5+ B cells in some diseases and their novel capacity to act as helper cells reflect the activities of a separate B-cell lineage. Because of these observations it is of particular interest to evaluate the factors which contribute to the maturation of the CD5+ B-cell subset. The possibility that CD5+ B cells produce a factor or factors capable of influencing their own development was the focus of the present investigation. Rather than attempt to obtain soluble factors from heterogeneous CD5+ B-cell populations which could be contaminated with cytokine secreting monocytes or which could require as yet undefined activation signals in order to secrete putative factors, we chose to evaluate the production of CD5+ B-cell inducing factor(s) by monoclonal CD5+ B-cell hybridomas. Added incentive to this approach was provided by the observation that these hybridomas elaborate a factor(s) which, together with (NPb) idiotype-specific antibody produced by the hybridoma, substitutes for CD5+ B-cell populations in activating antigen-specific (NPb idiotypic) B cells in vitro. Furthermore, because of the low percentage of CD5+ B cells in the spleen and their relatively low level of CD5 antigen expression, we employed a sensitive functional assay rather than surface antigen expression alone to detect small numbers of mature CD5+ B helper cells. With this previously described system it was possible to observe the induction of functional CD5+ B cells following a 40 h culture of apparently CD5- B-cell populations with a 19-22 kd factor or factors derived from a CD5+ B hybridoma. Data presented here and elsewhere suggest that this CD5+ B-cell inducing activity is not mediated by IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IFN-gamma, GM-CSF, or TNF. The role that such a B cell derived, B-cell directed factor may play in immunity and disease is discussed.
J Mol Cell Immunol 1990
PMID:A CD5+ B cell hybridoma derived factor(s), which induces maturation of CD5+, idiotype-specific B-cell populations. 169 80

To investigate the IL-6/IL-6 receptor system, we obtained five murine monoclonal antibodies against human IL-6, which neutralize its biological activity. We classified them into two groups (Type I mAb and Type II mAb) according to the epitopes they recognized. These two types of antibodies showed no difference in the manner in which they neutralized IL-6 activity, but they differed in the way they inhibited the binding of IL-6 to its receptor. While Type I mAb inhibited IL-6 binding to its receptor completely, Type II mAb inhibited only partially, even at a concn of Type II mAb sufficient to neutralize biological activity. Scatchard plot analysis revealed that in the case of the human myeloma cell line, the U266 cell, which showed two-phase binding of IL-6 to its receptor, the high affinity binding disappeared and the affinity of the low affinity binding decreased in the presence of Type II mAb. These results suggest that Type I mAb neutralizes IL-6 activity by the blocking of IL-6 binding to its receptor directly. In contrast, Type II mAb neutralizes IL-6 activity not by direct blocking of IL-6 binding to its receptor, but by modulating the binding affinity of IL-6 to its receptor, that is, inhibiting the formation of high affinity binding in IL-6 receptor system. This also indicates that the formation of high affinity may be necessary to transduce the IL-6 signal.
Mol Immunol 1991 Nov
PMID:Analysis of interleukin 6 (IL-6)/IL-6 receptor system using monoclonal anti-IL-6 antibodies. 172 May

Three different epitopes of the human IL-6 (IL-6) molecule were recognized by the mAb B-E4 (IgG2b), B-E8 (IgG1) and B-F6 (IgG1). The affinities of these three mAb for IL-6 differ little in several assays but if ranked by affinity they fall into the following order B-E8 greater than B-E4 greater than B-F6. B-E4 and B-E8 mAb, recognizing two different epitopes, are inhibiting mAb in the bioassay with the IL-6 depending cell line B9, however B-E8 has an inhibiting activity higher than B-E4. Both human natural IL-6 (HnIL-6) and human recombinant IL-6 (HrIL-6) were inhibited but not the murine natural IL-6 (MnIL-6). Surprisingly, not only the non-inhibiting mAb (B-F6) recognizes the HrIL-6 fixed to the receptor but also the inhibiting mAb B-E4 and B-E8. This together with the results obtained in a sandwich ELISA where the same mAb was used as both catcher and tracer to detect HrIL-6, it was concluded that dimeric HrIL-6 is able to fix the IL-6 receptor. Competition studies between monomeric HnIL-6 and dimeric HrIL-6 showed that the affinity of the dimeric HrIL-6 for the receptor was higher than that of HnIL-6.
Mol Immunol 1991 Nov
PMID:Human recombinant dimeric IL-6 binds to its receptor as detected by anti-IL-6 monoclonal antibodies. 172 May 1

One of the hallmarks of the granulomatous response to infection is the formation of multinucleated giant cells (MGC.) In an effort to study MGC, we examined the fusion-promoting effects of a variety of stimulating factors on human peripheral blood monocytes cultured on plastic surfaces in serum-supplemented media. MGC formation was minimally to moderately enhanced by interferon-gamma (IFN-gamma), interleukin (IL)-3, granulocyte/macrophage colony-stimulating factor (GM-CSF), 1,25-dihydroxycholecalciferol (1,25-(OH)2D3), retinoic acid (RA), and IL-6. IL-4 (which has been reported to promote MGC formation from murine macrophages) had an inhibitory effect. IFN-gamma was not required for MGC formation but it significantly increased the fusion-promoting activity of GM-CSF, 1,25-(OH)2D3, RA, and IL-6, IL-3, a hematopoietic growth factor, has been recently shown to induce osteoclast formation from murine bone marrow mononuclear cells. The most striking effect was seen with the combination of IL-3 and IFN-gamma. Fusion index is defined as a percentage of nuclei found within MGC, and an index of 67% at 1 wk was found. The formation of some very large cells with 50 to 100 nuclei was noted. Both Langhans' and foreign-body type cells were seen. Transmission electron micrographs clearly demonstrate the absence of plasma membrane between nuclei. Induction of MGC from peripheral human blood monocytes by IL-3 and IFN-gamma provides an in vitro system for the study of the formation and function of these cells.
Am J Respir Cell Mol Biol 1992 Jan
PMID:Induction of multinucleated giant cell formation from in vitro culture of human monocytes with interleukin-3 and interferon-gamma: comparison with other stimulating factors. 172 95

The peptide regulatory factors (PRFs), variously termed cytokines, lymphokines, interleukins, colony stimulating factors, interferons, etc., play a key role in the quantitative and qualitative regulation of protective responses--both in initiating immunological and inflammatory responses and in mediating and controlling the effector mechanisms that protect the body against micro-organisms. The process of immunization--involving antigen-presentation, lymphocyte-activation and clonal proliferation--depends on the action of a variety of PRFs. The function of accessory cells--the dendritic cells, macrophages, etc.--is stimulated by PRFs such as interferon-gamma, IL-1, TNF, GM-CSF and IL-4. The activation and expansion of T-lymphocytes requires IL-1, IL-2, IL-4, interferon-gamma, IL-6 and probably IL-7. Likewise, the activation and expansion of B-lymphocytes is regulated by PRFs such as IL-1, IL-2, IL-4, IL-5, IL-6, IL-7 and interferon-gamma. It is likely, although unproven, that PRFs also regulate the differentiation of B-cells to memory cells. Successful vaccination requires the immune system to be primed in such a way that natural challenge with a micro-organism or its products evokes an immune response that has the qualitative and the quantitative characteristics of both the humoral and cellular responses. Antibody class is critically influenced by particular PRFs, e.g. interferon-gamma regulates IgG2a; IL-4, IgE and IgG1; IL-5 and TGF-beta, IgA. PRFs are both produced by and regulate the T-lymphocytes which have key roles in protective responses--either directly, viz. the cytotoxic T-lymphocytes important in protection against certain viruses, or indirectly through the secretion of PRFs that regulate the speed, magnitude and quality of antibody cellular responses. The recruitment and enhanced production and function of granulocytic and phagocytic cells involves a number of T-lymphocyte PRFs including GM-CSF, IL-3, IL-5, IL-4, and IL-6. We do not have a good understanding of the fine-tuning of cellular responses nor of how infection with different pathogens results in different types of inflammatory responses; it is clear, however, that certain cellular responses are due to the action of specific PRFs, e.g. IL-3 induces a mastocytosis and IL-5 an eosinophilia. There is increasing evidence that the relative levels of different PRFs are important determinants of the effectiveness of responses.(ABSTRACT TRUNCATED AT 400 WORDS)
Mol Immunol 1991 Mar
PMID:Peptide regulatory factors and optimization of vaccines. 201 99

Anti-immunoglobulin (anti-Ig, anti-mu is commonly used) activates resting mouse B-cells to proliferate but not to differentiate and secrete Ig. Differentiation requires additional help from T-cells including soluble factors such as lymphokines. The capability of lymphokines, alone and in combination, to promote the differentiation of anti-mu activated B-cells has been investigated. Some lymphokines, like interleukin (IL) 2 and 3, as well as human-interferon beta-2 (IL-6), have no significant effect on differentiation. IL-4 and 5 maintain cell growth but do not lead to differentiation, which requires multiple factors present in ConA supernatant or partially purified TRF. Anti-mu and interferon-gamma (IFN-gamma) exert both positive and negative effects on B-cell maturation. Anti-mu induces cell proliferation. IFN-gamma enhances Ig transcription, but it has no apparent proliferation or differentiation activity. Anti-mu and IFN-gamma inhibit Ig secretion by causing the accumulation of nuclear mu-RNA precursors. Although phorbol ester plus ionomycin induce cell proliferation, the negative effect of anti-mu in RNA processing could not be mimicked by these reagents. I show that anti-mu and IFN-gamma interfere with the splicing of nuclear hnRNA. This phenomenon is independent of known 2'-5'(A)n synthetase activity. The data suggest that post-transcriptional regulation of mu-RNA processing might be a critical event in controlling the generation of the plasma cells (which secrete IgM), memory precursor cells or abortive cells (both of which do not secrete IgM).
Mol Immunol 1990 Dec
PMID:Analysis of cell proliferation and mu-RNA processing during activation of mouse B-cells by anti-mu and T lymphokines. 212 97

We examined expression and cytotoxic triggering capability of the three Fc receptors for IgG (Fc gamma R) on human monocytes, PMNs and myeloid cell lines after in vitro culture with various cytokines. Fc gamma R expression was evaluated using specific anti-Fc gamma R monoclonal antibodies (mAb). The cytotoxic capability of each Fc gamma R was examined after the effector cells were treated with the recombinant cytokines IFN-gamma. TNF alpha, GM-CSF, G-CSF, M-CSF, IL-1, IL-2, IL-3, IL-4, or IL-6. Hybridoma cell lines (HC) bearing antibody directed to Fc gamma RI (HC 32), Fc gamma RII (HC IV.3) or Fc gamma RIII (HC 3G8) were used as targets, as were chicken erythrocytes (CE) sensitized with heteroantibodies composed of anti-Fc gamma R mAbs (32, IV.3, 3G8) linked to anti-CE antibody. Only IFN-gamma treatment significantly increased Fc gamma R expression and then only Fc gamma RI. IFN-gamma dramatically up-regulated Fc gamma RI expression on all cells tested. However, ADCC was enhanced by treatment with a number of cytokines other than IFN-gamma. GM-CSF, TNF, and IFN-gamma treatment enhanced killing of HC 32 and HC IV.3 by in vitro cultured monocytes. G-CSF treatment enabled PMNs to kill HC through Fc gamma RII, whereas PMN killing of HC through Fc gamma RIII could not be induced by any of the cytokines studied. Although only IFN-gamma treatment increased ADCC of CE by monocytes, GM-CSF treatment as well as IFN-gamma treatment augmented ADCC of CE by PMNs. In addition to IFN-gamma treatment, IL-6 treatment enabled U937 cells to lyse CE. Whereas IFN-gamma-treated U937 cells killed CE through both Fc gamma RI and Fc gamma RII, IL-6-treated U937 cells killed CE only through Fc gamma RI. In addition to IFN-gamma treatment, G-CSF treatment enabled HL-60 cells to lyse CE through both Fc gamma RI and Fc gamma RII. These results demonstrate that although IFN-gamma appears unique in regulating Fc gamma R expression on myeloid cells, cytokines other than IFN-gamma affect ADCC by these cells in a receptor-specific manner.
Mol Immunol 1990 Jan
PMID:The effect of cytokines on the expression and function of Fc receptors for IgG on human myeloid cells. 213 46

Recent advances of T cell cloning have allowed the classification of T helper cells in terms of the lymphokines they secrete. The functional significance of segregating lymphokine production to unique T cell subsets is still being evaluated, but undoubtedly plays a key role in the regulatory mechanisms of the immune system. Initial studies have indicated that the Th1 cells which secrete IL-2 and IFN-gamma may be primarily responsible for augmenting cell-mediated responses, whereas Th2 cells, which release IL-4, IL-5, and IL-6, provide help for humoral responses. However, it is also known that B cells can respond to both IL-2 and IFN-gamma. This raises the question of the homogeneity of B lymphocyte activation requirements. Are all B cells responsive to all of the lymphokines with the end-result of stimulation depending largely on the relative concentrations of the various lymphokines, or are there B cell subsets which only respond to Th1-derived lymphokines and others which respond to Th2-derived lymphokines? Such differential activation requirements might be present to allow these subsets to play unique roles in immunological responses. Since B cell cloning techniques have not yet been developed to obtain a homogenous B cell population for studies of activation requirements, regulation of lymphokine receptors, and regulation of gene expression, we must utilize lymphokine-responsive neoplastic B cells. The vast majority of spontaneous B cell lymphomas appear to belong to a minor B cell subset which expresses the Ly1 marker. This subset is clearly not representative of the majority of splenic B cells.(ABSTRACT TRUNCATED AT 250 WORDS)
J Mol Cell Immunol 1990
PMID:Characterization of a neoplastic B cell clone that secretes IgM in response to Th2-derived lymphokines. 215 Apr 85

The effect of interleukin (IL)-6 and IL-1 on the biosynthesis of complement components C3, factor B, C2, C4 and C1 inhibitor (C1 inh), as well as that of albumin, was studied in vitro in human hepatoma-derived cell line, HepG2. Measuring the amounts of secreted complement proteins we detected a significant upregulation of C3 by both hormones. The enhancement of the factor B and especially that of C1 inh production was predominant by IL-6. In our experimental system neither IL-1 nor IL-6 affected the biosynthesis of C2 and C4. Albumin secretion was significantly decreased only in the simultaneous presence of IL-1 and IL-6. Detection of the changes in the amounts of C3- and factor B-specific mRNA of HepG2 cells suggests a pretranslational regulation by these cytokines. The secretion of C3 and factor B was markedly potentiated when IL-1 and IL-6 were added together. However only the gene expression of factor B, but not of C3, was found to reveal synergism. IL-6 enhanced the in vitro production of C3 in mouse hepatocytes as well. This effect was greatly potentiated in the presence of histamine.
Mol Immunol 1990 Feb
PMID:Hormonal regulation of complement biosynthesis in human cell lines--II. Upregulation of the biosynthesis of complement components C3, factor B and C1 inhibitor by interleukin-6 and interleukin-1 in human hepatoma cell line. 215 45


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