301
|
Murray BW, Bennett BL, Sasaki DT. Analysis of pharmacologic inhibitors of Jun N-terminal kinases. Methods Enzymol 2001; 332:432-52. [PMID: 11305116 DOI: 10.1016/s0076-6879(01)32220-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- B W Murray
- Agouron Pharmaceuticals, San Diego, California 92121-1408, USA
| | | | | |
Collapse
|
302
|
Su B, Cheng J, Yang J, Guo Z. MEKK2 is required for T-cell receptor signals in JNK activation and interleukin-2 gene expression. J Biol Chem 2001; 276:14784-90. [PMID: 11278622 DOI: 10.1074/jbc.m010134200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The c-Jun N-terminal kinases (JNKs) are members of the mitogen-activated protein kinase (MAPK) gene family and are essential for cell proliferation, differentiation, and apoptosis. Previously we found that activation of JNK in T-cells required costimulation of both T-cell receptor and auxiliary receptors such as CD28. In this study, we cloned a full-length human MEK kinase (MEKK) 2 cDNA from Jurkat T-cells and demonstrated that it was a major upstream MAPK kinase kinase for the JNK cascade in T-cells. The human MEKK2 cDNA encoded a polypeptide of 619 amino acids and was the human counterpart of the reported murine MEKK2. It was 94% homologous with human and murine MEKK3 at the catalytic domains and 60% homologous at the N-terminal noncatalytic region. Northern blot analysis showed that MEKK2 was ubiquitously expressed, with the highest level in peripheral blood leukocytes. In T cells, MEKK2 was found to be a strong activator of JNK but not of extracellular signal-regulated kinase MAPKs and to activate JNK-dependent AP-1 reporter gene expression. MEKK2 also synergized with anti-CD3 antibody to activate JNK in T cells, and stimulation of T cells led to induction of MEKK2 tyrosine phosphorylation. Significantly, the JNK activation induced by anti-CD3 and anti-CD28 antibodies, but not by 12-O-tetradecanoylphorbol-13-acetate and Ca(2+) ionophore A23187, was inhibited by dominant negative MEKK2 mutants. AP-1 and interleukin-2 reporter gene induction in T-cells was also inhibited by dominant negative MEKK2 mutants. Taken together, our results showed that human MEKK2 is a key signaling molecule for T-cell receptor/CD3-mediated JNK MAPK activation and interleukin-2 gene expression.
Collapse
Affiliation(s)
- B Su
- Department of Immunology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
| | | | | | | |
Collapse
|
303
|
Lu B, Yu H, Chow C, Li B, Zheng W, Davis RJ, Flavell RA. GADD45gamma mediates the activation of the p38 and JNK MAP kinase pathways and cytokine production in effector TH1 cells. Immunity 2001; 14:583-90. [PMID: 11371360 DOI: 10.1016/s1074-7613(01)00141-8] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The p38 and JNK stress-activated MAPK signal transduction pathways are activated by T cell receptor (TCR) signaling and are required for IFN-gamma production by TH1 effector cells. Here, we show that the expression of GADD45gamma is induced during T cell activation and that the level of expression is higher in TH1 cells than in TH2 cells. TH1 cells from GADD45gamma(-/-) mice are severely compromised in their abilities to activate p38 and JNK in response to TCR signaling, produce much less IFN-gamma upon restimulation, and are deficient in activation-induced cell death (AICD). Additionally, GADD45gamma deficiencies caused reduced contact hypersensitivity in mice. Thus, GADD45gamma mediates activation of the p38 and JNK pathways and effector function of TH1 cells.
Collapse
Affiliation(s)
- B Lu
- Section of Immunobiology and, Yale University School of Medicine, 310 Cedar Street, New Haven, CT 06520, USA
| | | | | | | | | | | | | |
Collapse
|
304
|
Dreskin SC, Thomas GW, Dale SN, Heasley LE. Isoforms of Jun kinase are differentially expressed and activated in human monocyte/macrophage (THP-1) cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:5646-53. [PMID: 11313405 DOI: 10.4049/jimmunol.166.9.5646] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ten isoforms of c-jun N-terminal kinase (JNK) have been described that arise by differential mRNA splicing of three genes. In that the relative expression and function of these different JNK proteins in human monocytic cells is not known, we have examined the JNK isoforms in THP-1 monocyte/macrophage cells. Differentiation of THP-1 cells by exposure to 10(-8) M PMA for 42-48 h enhances cellular responses to LPS, including enhanced activation of total JNK activity and increased phosphorylation of p54 JNK as well as p46 JNK. Examination of JNK proteins on Western blots reveals a predominance of p46 JNK1 and p54 JNK2 proteins. Clearing of lysates by immunoprecipitation of JNK1(99% effective) removes 46% of the JNK enzymatic activity (p < 0.01), whereas clearing of JNK1 plus JNK2 (70% effective) depletes the sample of 72% of the JNK activity (p < 0.01). Further analysis, undertaken with real-time RT-PCR, revealed that 98% of the JNK messages code for three isoforms: JNK1beta1, JNK2alpha1, and JNK2alpha2. The p54 JNK that is phosphorylated in LPS-stimulated, PMA-differentiated THP-1 cells is most likely JNK2alpha2 because 97% of the p54 JNK-encoding messages code for JNK2alpha2. By analogous reasoning, the p46 JNKs that are not heavily phosphorylated, but account for approximately half of the N-terminal c-jun kinase enzymatic activity, are most likely either JNK1beta1 or JNK2alpha1 because they account for 98% of the messages that can code for 46kDa JNKS:
Collapse
Affiliation(s)
- S C Dreskin
- Division of Allergy and Clinical Immunology, and Division of Nephrology, Departments of Medicine and Immunology, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
| | | | | | | |
Collapse
|
305
|
Abstract
Combinatorial regulation is a powerful mechanism that enables tight control of gene expression, via integration of multiple signaling pathways that induce different transcription factors required for enhanceosome assembly. The four calcium-regulated transcription factors of the NFAT family act synergistically with AP-1 (Fos/Jun) proteins on composite DNA elements which contain adjacent NFAT and AP-1 binding sites, where they form highly stable ternary complexes to regulate the expression of diverse inducible genes. Concomitant induction of NFAT and AP-1 requires concerted activation of two different signaling pathways: calcium/calcineurin, which promotes NFAT dephosphorylation, nuclear translocation and activation; and protein kinase C (PKC)/Ras, which promotes the synthesis, phosphorylation and activation of members of the Fos and Jun families of transcription factors. A fifth member of the NFAT family, NFAT5, controls the cellular response to osmotic stress, by a mechanism that requires dimer formation and is independent of calcineurin or of interaction with AP-1. Pharmacological interference with theNFAT:AP-1 interaction may be useful in selective manipulation of the immune response. Balanced activation of NFAT and AP-1 is known to be required for productive immune responses, but the role of NFAT:AP-1 interactions in other cell types and biological processes remains to be understood.
Collapse
Affiliation(s)
- F Macián
- Department of Pathology, Harvard Medical School and the Center for Blood Research, 200 Longwood Avenue, Boston, Massachusetts, MA 02115, USA
| | | | | |
Collapse
|
306
|
Affiliation(s)
- M Rincón
- Immunobiology Program, Department of Medicine, University of Vermont, Burlington, Vermont, VT 05405, USA
| | | | | |
Collapse
|
307
|
Herdegen T, Waetzig V. AP-1 proteins in the adult brain: facts and fiction about effectors of neuroprotection and neurodegeneration. Oncogene 2001; 20:2424-37. [PMID: 11402338 DOI: 10.1038/sj.onc.1204387] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Jun and Fos proteins are induced and activated following most physiological and pathophysiological stimuli in the brain. Only few data allow conclusions about distinct functions of AP-1 proteins in neurodegeneration and neuroregeneration, and these functions mainly refer to c-Jun and its activation by JNKs. Apoptotic functions of activated c-Jun affect hippocampal, nigral and primary cultured neurons following excitotoxic stimulation and destruction of the neuron-target-axis including withdrawal of trophic molecules. The inhibition of JNKs might exert neuroprotection by subsequent omission of c-Jun activation. Besides endogenous neuronal functions, the c-Jun/AP-1 proteins can damage the nervous system by upregulation of harmful programs in non-neuronal cells (e.g. microglia) with release of neurodegenerative molecules. In contrast, the differentiation with neurite extension and maturation of neural cells in vitro indicate physiological and potentially neuroprotective functions of c-Jun and JNKs including sensoring for alterations in the cytoskeleton. This review summarizes the multiple molecular interfunctions which are involved in the shift from the physiological role to degenerative effects of the Jun/JNK-axis such as cell type-specific expression and intracellular localization of scaffold proteins and upstream activators, antagonistic phosphatases, interaction with other kinase systems, or the activation of transcription factors competing for binding to JNK proteins and AP-1 DNA elements.
Collapse
Affiliation(s)
- T Herdegen
- Institute of Pharmacology, Hospitalstrasse 4, 24105 Kiel, Germany
| | | |
Collapse
|
308
|
Pearson G, Robinson F, Beers Gibson T, Xu BE, Karandikar M, Berman K, Cobb MH. Mitogen-activated protein (MAP) kinase pathways: regulation and physiological functions. Endocr Rev 2001; 22:153-83. [PMID: 11294822 DOI: 10.1210/edrv.22.2.0428] [Citation(s) in RCA: 1318] [Impact Index Per Article: 57.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitogen-activated protein (MAP) kinases comprise a family of ubiquitous proline-directed, protein-serine/threonine kinases, which participate in signal transduction pathways that control intracellular events including acute responses to hormones and major developmental changes in organisms. MAP kinases lie in protein kinase cascades. This review discusses the regulation and functions of mammalian MAP kinases. Nonenzymatic mechanisms that impact MAP kinase functions and findings from gene disruption studies are highlighted. Particular emphasis is on ERK1/2.
Collapse
Affiliation(s)
- G Pearson
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | | | | | | | | | | | | |
Collapse
|
309
|
Abstract
Mitogen-activated protein kinases (MAPKs) are important signal transducing enzymes, unique to eukaryotes, that are involved in many facets of cellular regulation. Initial research concentrated on defining the components and organization of MAPK signalling cascades, but recent studies have begun to shed light on the physiological functions of these cascades in the control of gene expression, cell proliferation and programmed cell death.
Collapse
Affiliation(s)
- L Chang
- Department of Pharmacology, University of California San Diego, La Jolla 92093-0636, USA
| | | |
Collapse
|
310
|
Yokoe T, Suzuki N, Minoguchi K, Adachi M, Sakane T. Analysis of IL-12 receptor beta 2 chain expression of circulating T lymphocytes in patients with atopic asthma. Cell Immunol 2001; 208:34-42. [PMID: 11277617 DOI: 10.1006/cimm.2001.1759] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Th2 cell predominance relative to Th1 cells contributes to pathological immune responses in patients with atopic asthma. IL-12 is a key cytokine in the induction of Th1 cells, and downregulation of IL-12 production is reported in these patients. However, IL-12 receptor expression of their T lymphocytes has not been clarified. In this study, expression of IL-12 receptor beta 2 on T cells and secretion of cytokines which affect IL-12 receptor beta 2 expression by their PBMC were examined. We found that IL-12 receptor beta 2 expression of the T cells is reduced. This is partly due to the diminished production of IL-12 and enhanced secretion of IL-4 by their PBMC. IL-18 production is not significantly modulated in these patients. Furthermore, intrinsic defects of the CD4(+) T cells, which reduce their IL-12 receptor beta 2 expression in response to IL-12 and/or IL-18 stimulation, are evident and are importantly involved in the Th1/Th2 imbalance of patients with atopic asthma.
Collapse
Affiliation(s)
- T Yokoe
- Department of Immunology, St. Marianna University School of Medicine, Kawasaki, Kanagawa 216-8511, Japan
| | | | | | | | | |
Collapse
|
311
|
Theofilopoulos AN, Koundouris S, Kono DH, Lawson BR. The role of IFN-gamma in systemic lupus erythematosus: a challenge to the Th1/Th2 paradigm in autoimmunity. ARTHRITIS RESEARCH 2001; 3:136-41. [PMID: 11299053 PMCID: PMC128889 DOI: 10.1186/ar290] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2001] [Accepted: 01/29/2001] [Indexed: 11/10/2022]
Abstract
The classification of T helper cells into type 1 (Th1) and type 2 (Th2) led to the hypothesis that Th1 cells and their cytokines (interleukin [IL]-2, interferon [IFN]-gamma) are involved in cell-mediated autoimmune diseases, and that Th2 cells and their cytokines (IL-4, IL-5, IL-10, IL-13) are involved in autoantibody(humoral)-mediated autoimmune diseases. However, this paradigm has been refuted by recent studies in several induced and spontaneous mouse models of systemic lupus erythematosus, which showed that IFN-gamma is a major effector molecule in this disease. These and additional findings, reviewed here, suggest that these two cross-talking classes of cytokines can exert autoimmune disease-promoting or disease-inhibiting effects without predictability or strict adherence to the Th1-versus-Th2 dualism.
Collapse
Affiliation(s)
- A N Theofilopoulos
- The Scripps Research Institute, Department of Immunology/IMM3, La Jolla, CA 92037, USA.
| | | | | | | |
Collapse
|
312
|
Behrens A, Sabapathy K, Graef I, Cleary M, Crabtree GR, Wagner EF. Jun N-terminal kinase 2 modulates thymocyte apoptosis and T cell activation through c-Jun and nuclear factor of activated T cell (NF-AT). Proc Natl Acad Sci U S A 2001; 98:1769-74. [PMID: 11172026 PMCID: PMC29332 DOI: 10.1073/pnas.98.4.1769] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2000] [Indexed: 12/22/2022] Open
Abstract
The Jun N-terminal kinases (JNKs) recently have been shown to be required for thymocyte apoptosis and T cell differentiation and/or proliferation. To investigate the molecular targets of JNK signaling in lymphoid cells, we used mice in which the serines phosphorylated by JNK in c-Jun were replaced by homologous recombination with alanines (junAA mice). Lymphocytes from these mice showed no phosphorylation of c-Jun in response to activation stimuli, whereas c-Jun was rapidly phosphorylated in wild-type cells. Despite the fact that c-jun is essential for early development, junAA mice develop normally; however, c-Jun N-terminal phosphorylation was required for efficient T cell receptor-induced and tumor necrosis factor-alpha-induced thymocyte apoptosis. In contrast, c-Jun phosphorylation by JNK is not required for T cell proliferation or differentiation. Because jnk2-/- T cells display a proliferation defect, we concluded that JNK2 must have other substrates required for lymphocyte function. Surprisingly, jnk2-/- T cells showed reduced NF-AT DNA-binding activity after activation. Furthermore, overexpression of JNK2 in Jurkat T cells strongly enhanced NF-AT-dependent transcription. These results demonstrate that JNK signaling differentially uses c-Jun and NF-AT as molecular effectors during thymocyte apoptosis and T cell proliferation.
Collapse
Affiliation(s)
- A Behrens
- Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, A-1030 Vienna, Austria
| | | | | | | | | | | |
Collapse
|
313
|
Sabapathy K, Kallunki T, David JP, Graef I, Karin M, Wagner EF. c-Jun NH2-terminal kinase (JNK)1 and JNK2 have similar and stage-dependent roles in regulating T cell apoptosis and proliferation. J Exp Med 2001; 193:317-28. [PMID: 11157052 PMCID: PMC2195924 DOI: 10.1084/jem.193.3.317] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Apoptotic and mitogenic stimuli activate c-Jun NH2-terminal kinases (JNKs) in T cells. Although T cells express both JNK1 and JNK2 isozymes, the absence of JNK2 alone can result in resistance to anti-CD3-induced thymocyte apoptosis and defective mature T cell proliferation. Similar defects in thymocyte apoptosis and mature T cell proliferation, the latter due to reduced interleukin 2 production, are also caused by JNK1 deficiency. Importantly, T cell function was compromised in Jnk1(+/-)Jnk2(+/-) double heterozygous mice, indicating that JNK1 and JNK2 play similar roles in regulating T cell function. The reduced JNK dose results in defective c-Jun NH2-terminal phosphorylation in thymocytes but not in peripheral T cells, in which nuclear factors of activated T cells (NK-ATs)-DNA binding activity is affected. Thus, JNK1 and JNK2 control similar functions during T cell maturation through differential targeting of distinct substrates.
Collapse
Affiliation(s)
- Kanaga Sabapathy
- Research Institute of Molecular Pathology, Vienna A 1030, Austria
| | - Tuula Kallunki
- Department of Pharmacology, School of Medicine, Cancer Center, University of California at San Diego, La Jolla, California 92093
| | | | - Isabella Graef
- Department of Pathology, Stanford Medical School, Stanford, California 94305
| | - Michael Karin
- Department of Pharmacology, School of Medicine, Cancer Center, University of California at San Diego, La Jolla, California 92093
| | - Erwin F. Wagner
- Research Institute of Molecular Pathology, Vienna A 1030, Austria
| |
Collapse
|
314
|
Yang J, Zhu H, Murphy TL, Ouyang W, Murphy KM. IL-18-stimulated GADD45 beta required in cytokine-induced, but not TCR-induced, IFN-gamma production. Nat Immunol 2001; 2:157-64. [PMID: 11175814 DOI: 10.1038/84264] [Citation(s) in RCA: 207] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Interleukin-12 (IL-12) and IL-18 induce synergistic transcription of interferon gamma (IFN-gamma) that is T cell receptor (TCR)-independent, not inhibited by cyclosporin A and requires new protein synthesis. To characterize this pathway, we screened for genes that are induced in IL-12- and IL-18-treated T helper type 1 cells. GADD45 beta, which activates mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase kinase 4 (MEKK4), was induced by IL-18 and augmented by IL-12. GADD45 beta expression in naïve CD4+ T cells activated p38 MAPK and selectively increased cytokine-induced, but not TCR-induced, IFN-gamma production. Kinase-inactive MEKK4 and inhibition of the p38 MAPK pathway both selectively inhibit cytokine-induced, but not TCR-induced, IFN-gamma production. Thus, the synergy between IL-12 and IL-18 may involve GADD45 beta induction, which can maintain the MEKK4 and p38 MAPK activation that is necessary for cytokine-induced, but not TCR-induced, IFN-gamma production.
Collapse
Affiliation(s)
- J Yang
- Department of Pathology and Immunology, Howard Hughes Medical Institute, Washington University School of Medicine, 660 South Euclid Ave., St. Louis, MO 63110, USA
| | | | | | | | | |
Collapse
|
315
|
Shirai M, Fujinaga R, Masaki T, Berzofsky JA. Impaired development of HIV-1 gp160-specific CD8(+) cytotoxic T cells by a delayed switch from Th1 to Th2 cytokine phenotype in mice with Helicobacter pylori infection. Eur J Immunol 2001; 31:516-26. [PMID: 11180117 DOI: 10.1002/1521-4141(200102)31:2<516::aid-immu516>3.0.co;2-l] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Th1 and Th2 cells play a central role in immunoregulation during infection. We show that Helicobacter pylori induces Th1 cytokine responses early (2 weeks) but predominantly Th2 responses later (6 weeks) in infection. The switch is principally mediated by urease-specific CD4(+) T cells, and correlates with a loss of urease-specific high-avidity JNK(+) Th1 and gain of low-avidity JNK(-) (possibly Th2) cells at the later stage of infection, concomitant with a 100-fold higher colonization level of H. pylori at 6 weeks than at 2 weeks that might tolerize high-avidity Th1 cells. Furthermore, differentiation of HIV gp160-specific CD4(+) Th and CD8(+) cytotoxic T lymphocytes (CTL) into effector cells is impaired in 6-week H. pylori-infected mice immunized with vaccinia expressing gp160, and serum IL-12 stimulated by vaccinia infection is barely detectable. Adoptive transfer of urease-specific Th2 cells to mice infected only with gp160-expressing vaccinia abrogates Th1 polarization of the gp120 response, down-modulates virus-specific CTL responses, and delays virus clearance. Therefore, the H. pylori urease-mediated immunoregulation in the switch from JNK(+) Th1 to JNK(-) Th2 phenotype, and the preceding low IL-12 response, are likely critical steps in the impairment of antiviral immunity.
Collapse
Affiliation(s)
- M Shirai
- Department of Microbiology, Yamaguchi University School of Medicine, Yamaguchi, Japan
| | | | | | | |
Collapse
|
316
|
Chapter 13 Mitogen-activated protein kinases and stress. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1568-1254(01)80015-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
317
|
Abstract
After activation, CD4 helper T (Th) cells differentiate into Th1or Th2 effector subsets. These two types of cells produce distinct profiles of cytokines and regulate different immune responses. This review summarizes recent progress on different features of co-stimulatory regulation and chemokine-mediated homing of Th1 and Th2 cells. Transcription factors and signaling pathways that are selectively expressed or activated in Th1 and Th2 cells to regulate cytokine gene expression are discussed.
Collapse
Affiliation(s)
- C Dong
- Department of Immunology, University of Washington School of Medicine, Seattle, USA
| | | |
Collapse
|
318
|
Lawless VA, Zhang S, Ozes ON, Bruns HA, Oldham I, Hoey T, Grusby MJ, Kaplan MH. Stat4 regulates multiple components of IFN-gamma-inducing signaling pathways. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:6803-8. [PMID: 11120802 DOI: 10.4049/jimmunol.165.12.6803] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Stat4 is activated in response to IL-12. Most functions of IL-12, including the induction of IFN-gamma, are compromised in the absence of Stat4. Since the precise role of Stat4 in IFN-gamma induction has not been established, experiments were conducted to examine Stat4 activation of IFN-gamma and other genes required for cytokine-induced expression of IFN-gamma. We first examined IL-12 signaling components. Basal expression of IL-12Rss1 and IL-12Rss2 is decreased in Stat4-deficient cells compared with that in control cells. However, IL-12 was still capable of inducing equivalent phosphorylation of Jak2 and Tyk2 in wild-type and Stat4-deficient activated T cells. We have further determined that other cytokine signaling pathways that induce IFN-gamma production are defective in the absence of Stat4. IL-18 induces minimal IFN-gamma production from Stat4-deficient activated T cells compared with control cells. This is due to defective IL-18 signaling, which results from the lack of IL-12-induced, and Stat4-dependent, expression of the IL-18R. Following IL-12 pretreatment to induce IL-18R, wild-type, but not Stat4-deficient, activated T cells demonstrated IL-18-induced NF-kappaB DNA-binding activity. In addition, IL-12-pretreated Stat4-deficient activated T cells have minimal IFN-gamma production followed by stimulation with IL-18 alone or in combination with IL-12 compared with control cells. Thus, Stat4 activation by IL-12 is required for the function of multiple cytokine pathways that result in induction of IFN-gamma.
Collapse
Affiliation(s)
- V A Lawless
- Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | | | | | | | | | | | | |
Collapse
|
319
|
Abstract
Cytokines such as interleukin 12 (IL-12) and IL-4 are dominant factors in driving the development of T helper 1 (Th1) and Th2 cells, respectively, through specific signalling pathways. In addition, it has been demonstrated more recently that T helper-cell-specific transcription factors exist that determine the commitment of Th1 and Th2 cells for the production of distinct profiles of cytokines. In addition to the expression of distinct cytokine genes and transcription factors, the molecular basis for commitment to a Th1 or Th2 phenotype can probably be explained by multiple mechanisms, including differential cytokine signalling, exclusive cytokine receptor expression, differential expression of transcription factors and/or differential chromatin remodelling of Th1- and Th2-specific genes.
Collapse
Affiliation(s)
- A O'Garra
- DNAX Research Institute, 901 California Avenue, Palo Alto CA 94304-1104, USA. Anne.O'
| | | |
Collapse
|
320
|
Diehl S, Anguita J, Hoffmeyer A, Zapton T, Ihle JN, Fikrig E, Rincón M. Inhibition of Th1 differentiation by IL-6 is mediated by SOCS1. Immunity 2000; 13:805-15. [PMID: 11163196 DOI: 10.1016/s1074-7613(00)00078-9] [Citation(s) in RCA: 312] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Interleukin 6 (IL-6) is a cytokine produced by immune and nonimmune cells and exhibits functional pleiotropy and redundancy. IL-6 plays an important role in the differentiation of several cell types. Here, we describe a novel function of IL-6: the negative regulation of CD4+ Th1 cell differentiation. While IL-6-directed CD4+ Th2 differentiation is mediated by IL-4, inhibition of Th1 differentiation by IL-6 is independent of IL-4. IL-6 upregulates suppressor of cytokine signaling 1 (SOCS1) expression in activated CD4+ T cells, thereby interfering with signal transducer and activator of transcription 1 (STAT1) phosphorylation induced by interferon gamma (IFNgamma). Inhibition of IFNgamma receptor-mediated signals by IL-6 prevents autoregulation of IFNgamma gene expression by IFNgamma during CD4+ T cell activation, thereby preventing Th1 differentiation. Thus, IL-6 promotes CD4+ Th2 differentiation and inhibits Th1 differentiation by two independent molecular mechanisms.
Collapse
Affiliation(s)
- Sean Diehl
- Department of Medicine, University of Vermont, Burlington 05405, USA
| | | | | | | | | | | | | |
Collapse
|
321
|
Noble A. Review article: molecular signals and genetic reprogramming in peripheral T-cell differentiation. Immunology 2000; 101:289-99. [PMID: 11106931 PMCID: PMC2327098 DOI: 10.1046/j.1365-2567.2000.00133.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Rearrangement of gene segments occurs in T lymphocytes during thymic development as the T-cell receptor (TCR) is first expressed, allowing T cells to become central regulators of antigen specificity in the acquired immune system. However, further development of T cells occurs after population of peripheral lymphoid tissues, which can result in T-cell expansion and differentiation into effectors of various immune function, or progression to memory T cells, anergic cells or death by apoptosis. This review focuses on more recent developments concerning the choices that peripheral T cells make between first encountering antigen through TCR recognition and death. These decisions are associated with a process of genetic reprogramming that alters the behaviour of cells so that immune responses are appropriately regulated.
Collapse
Affiliation(s)
- A Noble
- Department of Immunology, Guy's, King's & St Thomas' School of Medicine, London, UK
| |
Collapse
|
322
|
Chen Q, Ghilardi N, Wang H, Baker T, Xie MH, Gurney A, Grewal IS, de Sauvage FJ. Development of Th1-type immune responses requires the type I cytokine receptor TCCR. Nature 2000; 407:916-20. [PMID: 11057672 DOI: 10.1038/35038103] [Citation(s) in RCA: 318] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
On antigen challenge, T-helper cells differentiate into two functionally distinct subsets, Th1 and Th2, characterized by the different effector cytokines that they secrete. Th1 cells produce interleukin (IL)-2, interferon-gamma (IFN-gamma) and lymphotoxin-beta, which mediate pro-inflammatory functions critical for the development of cell-mediated immune responses, whereas Th2 cells secrete cytokines such as IL-4, IL-5 and IL-10 that enhance humoral immunity. This process of T-helper cell differentiation is tightly regulated by cytokines. Here we report a new member of the type I cytokine receptor family, designated T-cell cytokine receptor (TCCR). When challenged in vivo with protein antigen, TCCR-deficient mice had impaired Th1 response as measured by IFN-gamma production. TCCR-deficient mice also had increased susceptibility to infection with an intracellular pathogen, Listeria monocytogenes. In addition, levels of antigen-specific immunoglobulin-gamma2a, which are dependent on Th1 cells, were markedly reduced in these mice. Our results demonstrate the existence of a new cytokine receptor involved in regulating the adaptive immune response and critical to the generation of a Th1 response.
Collapse
Affiliation(s)
- Q Chen
- Department of Molecular Oncology, Genentech, Inc, South San Francisco, California 94080, USA
| | | | | | | | | | | | | | | |
Collapse
|
323
|
Affiliation(s)
- R J Davis
- Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester 01605, USA.
| |
Collapse
|
324
|
Abstract
Following an overview of the biochemistry of mitogen-activated protein kinase (MAPK) pathways, the relevance of these signaling events to specific models of renal cell function and pathophysiology, both in vitro and in vivo, will be emphasized. In in vitro model systems, events activating the principal MAPK families [extracellular signal-regulated and c-Jun NH(2)-terminal kinase and p38] have been best characterized in mesangial and tubular epithelial cell culture systems and include peptide mitogens, cytokines, lipid mediators, and physical stressors. Several in vivo models of proliferative or toxic renal injury are also associated with aberrant MAPK regulation. It is anticipated that elucidation of downstream effector signaling mechanisms and a clearer understanding of the immediate and remote upstream activating pathways, when applied to these highly clinically relevant model systems, will ultimately provide much greater insight into the basis for specificity now seemingly absent from these signaling events.
Collapse
Affiliation(s)
- W Tian
- Divisions of Nephrology and Molecular Medicine, Oregon Health Sciences University, and Portland Veterans Affairs Medical Center, Portland, Oregon 97201, USA
| | | | | |
Collapse
|
325
|
Goodbourn S, Didcock L, Randall RE. Interferons: cell signalling, immune modulation, antiviral response and virus countermeasures. J Gen Virol 2000; 81:2341-2364. [PMID: 10993923 DOI: 10.1099/0022-1317-81-10-2341] [Citation(s) in RCA: 749] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- S Goodbourn
- Department of Biochemistry and Immunology, St George's Hospital Medical School, University of London, London SW17 0RE, UK1
| | - L Didcock
- Biomolecular Sciences Building, North Haugh, University of St Andrews, Fife KY16 9TS, UK2
| | - R E Randall
- Biomolecular Sciences Building, North Haugh, University of St Andrews, Fife KY16 9TS, UK2
| |
Collapse
|
326
|
Lipopolysaccharide induces Jun N-terminal kinase activation in macrophages by a novel Cdc42/Rac-independent pathway involving sequential activation of protein kinase C ζ and phosphatidylcholine-dependent phospholipase C. Blood 2000. [DOI: 10.1182/blood.v96.7.2592] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractThe activation of kinases of the mitogen-activated protein kinase superfamily initiated by lipopolysaccharide (LPS) plays an important role in transducing inflammatory signals. The pathway leading to the induction of stress-activated protein kinases in macrophages stimulated with LPS was investigated. The activation of Jun N-terminal kinases (JNK) by LPS is herbimycin sensitive. Using specific inhibitors, it was shown that the pathway involves the activation of phosphoinositide 3-kinase (PI 3-K). However, in contrast to previous reports, the small GTPases Cdc42 and Rac are not required downstream of PI 3-K for JNK activation. Instead, the phosphoinositides produced by PI 3-K stimulate protein kinase C (PKC) ζ activation through PDK1. In turn, activation of this atypical PKC leads to the stimulation of phosphatidylcholine phospholipase C (PC-PLC) and acidic sphingomyelinase (ASMase). It is therefore proposed that PKCζ regulates the PC-PLC/ASMase pathway, and it is hypothesized that the resultant ceramide accumulation mediates the activation of the SEK/JNK module by LPS.
Collapse
|
327
|
Lipopolysaccharide induces Jun N-terminal kinase activation in macrophages by a novel Cdc42/Rac-independent pathway involving sequential activation of protein kinase C ζ and phosphatidylcholine-dependent phospholipase C. Blood 2000. [DOI: 10.1182/blood.v96.7.2592.h8002592_2592_2598] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The activation of kinases of the mitogen-activated protein kinase superfamily initiated by lipopolysaccharide (LPS) plays an important role in transducing inflammatory signals. The pathway leading to the induction of stress-activated protein kinases in macrophages stimulated with LPS was investigated. The activation of Jun N-terminal kinases (JNK) by LPS is herbimycin sensitive. Using specific inhibitors, it was shown that the pathway involves the activation of phosphoinositide 3-kinase (PI 3-K). However, in contrast to previous reports, the small GTPases Cdc42 and Rac are not required downstream of PI 3-K for JNK activation. Instead, the phosphoinositides produced by PI 3-K stimulate protein kinase C (PKC) ζ activation through PDK1. In turn, activation of this atypical PKC leads to the stimulation of phosphatidylcholine phospholipase C (PC-PLC) and acidic sphingomyelinase (ASMase). It is therefore proposed that PKCζ regulates the PC-PLC/ASMase pathway, and it is hypothesized that the resultant ceramide accumulation mediates the activation of the SEK/JNK module by LPS.
Collapse
|
328
|
Affiliation(s)
- C Y Kuan
- Section of Neurobiology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | | | | |
Collapse
|
329
|
Dong C, Flavell RA. Control of T helper cell differentiation--in search of master genes. SCIENCE'S STKE : SIGNAL TRANSDUCTION KNOWLEDGE ENVIRONMENT 2000; 2000:pe1. [PMID: 11752608 DOI: 10.1126/stke.2000.49.pe1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Naïve T helper (T(H)0) cells can differentiate into one of two distinct populations: T(H)1 and T(H)2. Each population is characterized by the expression of specific cytokines and their ability to participate in cell-mediated or humoral immune responses. Recent efforts at identifying the molecular mechanisms through which T(H)0 cells become T(H)1 or T(H)2 cells have been promising. A number of transcription factors, including GATA-3 and T-bet, have been identified that promote the differentiation of T(H)0 cells and the maintenance of the differentiated cell phenotype. Dong and Flavell review recent findings on proteins that control the fate of T(H)0 differentiation, whether by promotion or inhibition, and discuss the role of epigenesis in the differentiation process.
Collapse
Affiliation(s)
- C Dong
- Section of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | | |
Collapse
|
330
|
Abstract
Understanding the control exerted by cytokines on T helper cell subsets 1 and 2 (TH1-TH2) development has progressed to a fairly satisfying knowledge of intracellular signals and transcription factors. Less is understood about the molecular basis of TH1-TH2 development exerted by other parameters, such as how the antigen presenting cell can influence this process. Recent work suggests that dendritic cell subsets contribute significant polarizing influences on T helper differentiation, but how this comes about is less clear. In some cases known pathways may be used, as in the dendritic cell subset 1 exerting TH1 polarization by interleukin 12 (IL-12) production and STAT4 activation. In others, the effects are still in need of explanation.
Collapse
Affiliation(s)
- M Moser
- Département de Biologie Moleculaire, Université Libre de Bruxelles, Rue des Prof. Jeener et Brochet 12, 6041 Gosselies, Belgium
| | | |
Collapse
|
331
|
Nichols A, Camps M, Gillieron C, Chabert C, Brunet A, Wilsbacher J, Cobb M, Pouyssegur J, Shaw JP, Arkinstall S. Substrate recognition domains within extracellular signal-regulated kinase mediate binding and catalytic activation of mitogen-activated protein kinase phosphatase-3. J Biol Chem 2000; 275:24613-21. [PMID: 10811804 DOI: 10.1074/jbc.m001515200] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mitogen-activated protein (MAP) kinase phosphatase-3 (MKP-3) is a dual specificity phosphatase that inactivates extracellular signal-regulated kinase (ERK) MAP kinases. This reflects tight and specific binding between ERK and the MKP-3 amino terminus with consequent phosphatase activation and dephosphorylation of the bound MAP kinase. We have used a series of p38/ERK chimeric molecules to identify domains within ERK necessary for binding and catalytic activation of MKP-3. These studies demonstrate that ERK kinase subdomains V-XI are necessary and sufficient for binding and catalytic activation of MKP-3. These domains constitute the major COOH-terminal structural lobe of ERK. p38/ERK chimeras possessing these regions display increased sensitivity to inactivation by MKP-3. These data also reveal an overlap between ERK domains interacting with MKP-3 and those known to confer substrate specificity on the ERK MAP kinase. Consistent with this, we show that peptides representing docking sites within the target substrates Elk-1 and p90(rsk) inhibit ERK-dependent activation of MKP-3. In addition, abolition of ERK-dependent phosphatase activation following mutation of a putative kinase interaction motif (KIM) within the MKP-3 NH(2) terminus suggests that key sites of contact for the ERK COOH-terminal structural lobe include residues localized between the Cdc25 homology domains (CH2) found conserved between members of the DSP gene family.
Collapse
Affiliation(s)
- A Nichols
- Serono Pharmaceutical Research Institute, Ares-Serono International SA, Plan-les-Ouates 1228, Geneva, Switzerland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
332
|
Zhang S, Kaplan MH. The p38 mitogen-activated protein kinase is required for IL-12-induced IFN-gamma expression. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:1374-80. [PMID: 10903740 DOI: 10.4049/jimmunol.165.3.1374] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IL-12 is a central immunoregulatory cytokine that promotes cell-mediated immune responses and the differentiation of naive CD4+ cells into Th1 cells. We and others have demonstrated that the Stat4 is critical for IFN-gamma production by activated T cells and Th1 cells. However, several studies have suggested that other pathways may be involved in IL-12-stimulated IFN-gamma expression. In this report we demonstrate that IL-12 activates mitogen-activated protein kinase kinase 3/6 (MKK) and p38 mitogen-activated protein kinase (MAPK), but not p44/42 (ERK) or stress-activated protein kinase/c-Jun N-terminal kinase MAPK. The activation of p38 MAPK is required for normal induction of IFN-gamma mRNA and IFN-gamma secretion by IL-12 in activated T cells and Th1 cells. Importantly, IL-12-stimulated p38 MAPK effector functions occur through a Stat4-independent mechanism and correlate with increased serine phosphorylation of activating transcription factor-2. The requirement for p38 MAPK in IL-12 function suggests that this pathway may be an important in vivo target for the anti-inflammatory actions of p38 MAPK inhibitors.
Collapse
Affiliation(s)
- S Zhang
- Department of Microbiology and Immunology, Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | |
Collapse
|
333
|
Werlen G, Hausmann B, Palmer E. A motif in the alphabeta T-cell receptor controls positive selection by modulating ERK activity. Nature 2000; 406:422-6. [PMID: 10935640 DOI: 10.1038/35019094] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Positive selection allows thymocytes that recognize an individual's own major histocompatibility complex (self-MHC) molecules to survive and differentiate, whereas negative selection removes overtly self-reactive thymocytes. Although both forms of thymic selection are mediated by the alphabeta T-cell receptor (TCR) and require self-MHC recognition, an important question is whether they are controlled by distinct signalling cascades. We have shown that mutation of an essential motif within the TCR alpha-chain-connecting peptide domain (alpha-CPM) profoundly affects positive but not negative selection. Using transgenic mice expressing a mutant alpha-CPM TCR we examined the contribution of several mitogen-activated protein kinase (MAPK) cascades to thymic selection. Here we show that in thymocytes expressing a mutant alpha-CPM receptor, a positively selecting peptide failed to activate the extracellular signal-regulated kinase (ERK), although other MAPK cascades were induced normally. The defect in ERK activation was associated with impaired recruitment of the activated tyrosine kinases Lck and ZAP-70, phosphorylated forms of the TCR component CD3zeta and the adaptor protein LAT to detergent-insoluble glycolipid-enriched microdomains (DIGs). Therefore, an intact DIG-associated signalosome is essential for sustained ERK activation, which leads to positive selection.
Collapse
MESH Headings
- Amino Acid Motifs
- Animals
- Binding Sites
- Cell Line
- Enzyme Activation
- Leukopoiesis/physiology
- MAP Kinase Signaling System
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Mitogen-Activated Protein Kinases/metabolism
- Mutation
- Oligopeptides/metabolism
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/physiology
- Signal Transduction
- Thymus Gland/cytology
Collapse
Affiliation(s)
- G Werlen
- Basel Institute for Immunology, Switzerland.
| | | | | |
Collapse
|
334
|
Murphy KM, Ouyang W, Farrar JD, Yang J, Ranganath S, Asnagli H, Afkarian M, Murphy TL. Signaling and transcription in T helper development. Annu Rev Immunol 2000; 18:451-94. [PMID: 10837066 DOI: 10.1146/annurev.immunol.18.1.451] [Citation(s) in RCA: 480] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The recognition of polarized T cell subsets defined by cytokine production was followed by a search to define the factors controlling this phenomenon. Suitable in vitro systems allowed the development of cytokine "recipes" that induced rapid polarization of naïve T cells into Th1 or Th2 populations. The next phase of work over the past several years has begun to define the intracellular processes set into motion during Th1/Th2 development, particularly by the strongly polarizing cytokines IL-12 and IL-4. Although somewhat incomplete, what has emerged is a richly detailed tapestry of signaling and transcription, controlling an important T cell developmental switch. In addition several new mediators of control have emerged, including IL-18, the intriguing Th2-selective T1/ST2 product, and heterogeneity in dendritic cells capable of directing cytokine-independent Th development.
Collapse
Affiliation(s)
- K M Murphy
- Department of Pathology, and Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | | | | | | | | | | | | | | |
Collapse
|
335
|
Glimcher LH, Murphy KM. Lineage commitment in the immune system: the T helper lymphocyte grows up. Genes Dev 2000. [DOI: 10.1101/gad.14.14.1693] [Citation(s) in RCA: 236] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
336
|
Lee HJ, Takemoto N, Kurata H, Kamogawa Y, Miyatake S, O'Garra A, Arai N. GATA-3 induces T helper cell type 2 (Th2) cytokine expression and chromatin remodeling in committed Th1 cells. J Exp Med 2000; 192:105-15. [PMID: 10880531 PMCID: PMC1887713 DOI: 10.1084/jem.192.1.105] [Citation(s) in RCA: 317] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Committed T helper type 1 (Th1) and Th2 effector cells, resulting from chronic antigenic stimulation in interleukin (IL)-12 and IL-4, are implicated in the pathology of autoimmune and allergic diseases. Committed Th1 cells cannot be induced to change their cytokine profiles in response to antigenic stimulation and Th2 cytokine-inducing conditions. Here, we report that ectopic expression of GATA-3 induced Th2-specific cytokine expression not only in developing Th1 cells but also in otherwise irreversibly committed Th1 cells and a Th1 clone, HDK1. Moreover, cAMP, an inhibitor of cytokine production by Th1 cells, markedly augmented Th2 cytokine production in GATA-3-expressing Th1 cells. Ectopic expression of GATA-3 in developing Th1 cells, but not in Th1 clone HDK1, induced endogenous GATA-3, suggesting an autoregulatory mechanism for maintenance of GATA-3 expression in Th2 cells. Structure-function analyses of GATA-3 revealed that the NH(2)-terminal transactivation domain and the COOH-terminal zinc finger domain of GATA-3 were critical, whereas the NH(2)-terminal zinc finger domain was dispensable for the induction of IL-4. Both zinc fingers, however, were required for IL-5 induction. A Th2-specific DNaseI-hypersensitive site of the IL-4 locus was detected in GATA-3-expressing Th1 cells. Thus, GATA-3 can change the phenotype of committed Th1 cells, previously considered to be irreversible.
Collapse
Affiliation(s)
- Hyun Jun Lee
- Department of Immunology, DNAX Research Institute, Palo Alto, California 94304-1104
| | - Naofumi Takemoto
- Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Tokyo 108-0071, Japan
| | - Hirokazu Kurata
- Department of Immunology, DNAX Research Institute, Palo Alto, California 94304-1104
| | - Yumiko Kamogawa
- Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Tokyo 108-0071, Japan
- Core Research for Evolutionary Science and Technology (CREST), Saitama 332-0012, Japan
| | - Shoichiro Miyatake
- Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Tokyo 108-0071, Japan
- Core Research for Evolutionary Science and Technology (CREST), Saitama 332-0012, Japan
| | - Anne O'Garra
- Department of Immunology, DNAX Research Institute, Palo Alto, California 94304-1104
| | - Naoko Arai
- Department of Immunology, DNAX Research Institute, Palo Alto, California 94304-1104
| |
Collapse
|
337
|
Chow CW, Dong C, Flavell RA, Davis RJ. c-Jun NH(2)-terminal kinase inhibits targeting of the protein phosphatase calcineurin to NFATc1. Mol Cell Biol 2000; 20:5227-34. [PMID: 10866678 PMCID: PMC85971 DOI: 10.1128/mcb.20.14.5227-5234.2000] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2000] [Accepted: 04/12/2000] [Indexed: 11/20/2022] Open
Abstract
The protein phosphatase calcineurin is a critical mediator of calcium signals during T-cell activation. One substrate of calcineurin is the transcription factor NFATc1, which is retained in the cytoplasm of quiescent cells. NFATc1 activation requires the translocation of the transcription factor into the nucleus, a process that is mediated by calcineurin. This interaction with calcineurin requires a targeting domain (PxIxIT motif) located in the NH(2)-terminal region of NFATc1. Here we demonstrate that the calcineurin targeting domain of NFATc1 is phosphorylated and inactivated by the c-Jun NH(2)-terminal kinase (JNK). This disruption of calcineurin targeting inhibits the nuclear accumulation and transcription activity of NFATc1 and accounts for the observation that Jnk1(-/-) T cells exhibit greatly increased NFATc1-dependent nuclear responses.
Collapse
Affiliation(s)
- C W Chow
- Howard Hughes Medical Institute, Program in Molecular Medicine, Department of Biochemistry and Molecular Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | | | | | | |
Collapse
|
338
|
Li B, Yu H, Zheng W, Voll R, Na S, Roberts AW, Williams DA, Davis RJ, Ghosh S, Flavell RA. Role of the guanosine triphosphatase Rac2 in T helper 1 cell differentiation. Science 2000; 288:2219-22. [PMID: 10864872 DOI: 10.1126/science.288.5474.2219] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
T helper 1 (TH1) cells mediate cellular immunity, whereas TH2 cells potentiate antiparasite and humoral immunity. We used a complementary DNA subtraction method, representational display analysis, to show that the small guanosine triphosphatase Rac2 is expressed selectively in murine TH1 cells. Rac induces the interferon-gamma (IFN-gamma) promoter through cooperative activation of the nuclear factor kappa B and p38 mitogen-activated protein kinase pathways. Tetracycline-regulated transgenic mice expressing constitutively active Rac2 in T cells exhibited enhanced IFN-gamma production. Dominant-negative Rac inhibited IFN-gamma production in murine T cells. Moreover, T cells from Rac2-/- mice showed decreased IFN-gamma production under TH1 conditions in vitro. Thus, Rac2 activates TH1-specific signaling and IFN-gamma gene expression.
Collapse
Affiliation(s)
- B Li
- Section of Immunobiology and Howard Hughes Medical Institute, Yale University School of Medicine, 310 Cedar Street, New Haven, CT 06520-8011, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
339
|
Yujiri T, Ware M, Widmann C, Oyer R, Russell D, Chan E, Zaitsu Y, Clarke P, Tyler K, Oka Y, Fanger GR, Henson P, Johnson GL. MEK kinase 1 gene disruption alters cell migration and c-Jun NH2-terminal kinase regulation but does not cause a measurable defect in NF-kappa B activation. Proc Natl Acad Sci U S A 2000; 97:7272-7. [PMID: 10852963 PMCID: PMC16535 DOI: 10.1073/pnas.130176697] [Citation(s) in RCA: 204] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
MEK kinase 1 (MEKK1) is a 196-kDa mitogen-activated protein kinase (MAPK) kinase kinase that, in addition to regulating the c-Jun NH(2)-terminal kinase (JNK) pathway, is involved in the control of cell motility. MEKK1(-/-) mice are defective in eyelid closure, a TGFalpha-directed process involving the migration of epithelial cells. MEKK1 expression in epithelial cells stimulates lamellipodia formation, a process required for cell movement. In addition, mouse embryo fibroblasts derived from MEKK1(-/-) mice are inhibited in their migration relative to MEKK1(+/+) fibroblasts. MEKK1 is required for JNK but not NF-kappaB activation in response to virus infection, microtubule disruption, and stimulation of embryonic stem cells with lysophosphatidic acid. MEKK1 is not required for TNFalpha or IL-1 regulation of JNK or NF-kappaB activation in macrophages or fibroblasts. Thus, MEKK1 senses microtubule integrity, contributes to the regulation of fibroblast and epithelial cell migration, and is required for activation of JNK but not NF-kappaB in response to selected stress stimuli.
Collapse
Affiliation(s)
- T Yujiri
- Third Department of Internal Medicine, Yamaguchi University School of Medicine, Yamaguchi, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
340
|
Yamashita M, Katsumata M, Iwashima M, Kimura M, Shimizu C, Kamata T, Shin T, Seki N, Suzuki S, Taniguchi M, Nakayama T. T cell receptor-induced calcineurin activation regulates T helper type 2 cell development by modifying the interleukin 4 receptor signaling complex. J Exp Med 2000; 191:1869-79. [PMID: 10839803 PMCID: PMC2213529 DOI: 10.1084/jem.191.11.1869] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The activation of downstream signaling pathways of both T cell receptor (TCR) and interleukin 4 receptor (IL-4R) is essential for T helper type 2 (Th2) cell development, which is central to understanding immune responses against helminthic parasites and in allergic and autoimmune diseases. However, little is known about how these two distinct signaling pathways cooperate with each other to induce Th2 cells. Here, we show that successful Th2 cell development depends on the effectiveness of TCR-induced activation of calcineurin. An inhibitor of calcineurin activation, FK506, inhibited the in vitro anti-TCR-induced Th2 cell generation in a dose-dependent manner. Furthermore, the development of Th2 cells was significantly impaired in naive T cells from dominant-negative calcineurin Aalpha transgenic mice, whereas that of Th1 cells was less affected. Efficient calcineurin activation in naive T cells upregulated Janus kinase (Jak)3 transcription and the amount of protein. The generation of Th2 cells induced in vitro by anti-TCR stimulation was inhibited significantly by the presence of Jak3 antisense oligonucleotides, suggesting that the Jak3 upregulation is an important event for the Th2 cell development. Interestingly, signal transducer and activator of transcription (STAT)5 became physically and functionally associated with the IL-4R in the anti-TCR-activated developing Th2 cells that received efficient calcineurin activation, and also in established cloned Th2 cells. In either cell population, the inhibition of STAT5 activation resulted in a diminished IL-4-induced proliferation. Moreover, our results suggest that IL-4-induced STAT5 activation is required for the expansion process of developing Th2 cells. Thus, Th2 cell development is controlled by TCR-mediated activation of the Ca(2+)/calcineurin pathway, at least in part, by modifying the functional structure of the IL-4R signaling complex.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- Calcineurin/genetics
- Calcineurin/metabolism
- Cell Differentiation
- Cell Division
- Cells, Cultured
- DNA-Binding Proteins/metabolism
- Gene Expression
- Interleukin-4/metabolism
- Janus Kinase 3
- Lymphocyte Activation
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Transgenic
- Milk Proteins
- Molecular Sequence Data
- Oligodeoxyribonucleotides, Antisense
- Protein-Tyrosine Kinases/genetics
- Protein-Tyrosine Kinases/metabolism
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Receptors, Interleukin-4/metabolism
- STAT5 Transcription Factor
- Signal Transduction
- Th1 Cells/cytology
- Th2 Cells/cytology
- Th2 Cells/metabolism
- Trans-Activators/metabolism
Collapse
Affiliation(s)
- Masakatsu Yamashita
- Department of Developmental Immunology, Chiba University School of Medicine, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Makoto Katsumata
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6082
| | - Makio Iwashima
- Program in Molecular Immunology, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia 30912-2600
| | - Motoko Kimura
- Department of Molecular Immunology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Chiori Shimizu
- Department of Molecular Immunology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Tohru Kamata
- Department of Molecular Immunology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Tahiro Shin
- Department of Molecular Immunology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Nobuo Seki
- Medicinal Biology Research Laboratories, Fujisawa Pharmaceutical Company, Limited, Osaka 532, Japan
| | - Seiichi Suzuki
- Department of Experimental Surgery and Bioengineering, National Children's Medical Research Center, Tokyo 154, Japan
| | - Masaru Taniguchi
- Department of Molecular Immunology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Toshinori Nakayama
- Department of Molecular Immunology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| |
Collapse
|
341
|
Abstract
The past several years have seen the beginning of a shift in the way that TCR signal transduction is studied. Although many investigators continue to identify new molecules, particularly adaptor proteins, others have attempted to look at signaling events in a larger cellular context. Thus the identification of distinct formations of signaling molecules at junctions between T cells and antigen-presenting cells, the role of the cytoskeleton and the partitioning of molecules into specialized lipid subdomains have been the subjects of many publications. Such concepts are helping to assemble a blueprint of how the myriad adaptors and kinases fit together to effect T cell activation.
Collapse
Affiliation(s)
- L P Kane
- Department of Medicine, The Howard Hughes Medical Institute, University of California (San Francisco), San Francisco, CA 94143-0795, USA
| | | | | |
Collapse
|
342
|
Tournier C, Hess P, Yang DD, Xu J, Turner TK, Nimnual A, Bar-Sagi D, Jones SN, Flavell RA, Davis RJ. Requirement of JNK for stress-induced activation of the cytochrome c-mediated death pathway. Science 2000; 288:870-4. [PMID: 10797012 DOI: 10.1126/science.288.5467.870] [Citation(s) in RCA: 1358] [Impact Index Per Article: 56.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The c-Jun NH2-terminal kinase (JNK) is activated when cells are exposed to ultraviolet (UV) radiation. However, the functional consequence of JNK activation in UV-irradiated cells has not been established. It is shown here that JNK is required for UV-induced apoptosis in primary murine embryonic fibroblasts. Fibroblasts with simultaneous targeted disruptions of all the functional Jnk genes were protected against UV-stimulated apoptosis. The absence of JNK caused a defect in the mitochondrial death signaling pathway, including the failure to release cytochrome c. These data indicate that mitochondria are influenced by proapoptotic signal transduction through the JNK pathway.
Collapse
Affiliation(s)
- C Tournier
- Howard Hughes Medical Institute, Program in Molecular Medicine, Department of Biochemistry & Molecular Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
343
|
Dong C, Yang DD, Tournier C, Whitmarsh AJ, Xu J, Davis RJ, Flavell RA. JNK is required for effector T-cell function but not for T-cell activation. Nature 2000; 405:91-4. [PMID: 10811224 DOI: 10.1038/35011091] [Citation(s) in RCA: 254] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The hallmark of T-cell activation is the production of interleukin 2 (IL-2). c-Jun amino-terminal kinase (JNK), a MAP kinase that phosphorylates c-Jun and other components of the AP-1 group of transcription factors, has been implicated in the activation of IL-2 expression. Previously, we found that T cells from mice deficient in the Jnk1 or Jnk2 gene can be activated and produce IL-2 normally, but are deficient in functional differentiation into Th1 or Th2 subsets. However, studies of mice with compound mutations indicate that JNK1 and JNK2 are redundant during mouse development. Here we use three new mouse models in which peripheral T cells completely lack JNK proteins or signalling, to test whether the JNK signalling pathway is crucial for IL-2 expression and T-cell activation. Unexpectedly, these T cells made more IL-2 and proliferated better than wild-type cells. However, production of effector T-cell cytokines did require JNK. Thus, JNK is necessary for T-cell differentiation but not for naive T-cell activation.
Collapse
Affiliation(s)
- C Dong
- Howard Hughes Medical Institute, Section of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | | | | | | | | | | | | |
Collapse
|
344
|
Abstract
Dendritic cells (DC) are professional antigen-presenting cells with a unique capacity to initiate and regulate immune responses. Immature CD1a+ DC can be cultured from CD14+monocytes in the presence of interleukin (IL)-4 and granulocyte macrophage colony-stimulating factor in vitro. Results of this study show that the nonsteroidal anti-estrogens toremifene and tamoxifen inhibit this differentiation. In the presence of anti-estrogens the cells lose CD14 expression, but remain CD1a− and clearly have less dendritic processes than immature DC. Functionally, anti-estrogen-treated cells are inferior to immature DC in inducing proliferation of allogeneic T cells and in producing IL-12 p70 protein after CD40 ligation. The expression of the costimulatory molecules CD80 and CD86 is differentially regulated by anti-estrogens during DC differentiation. Furthermore, anti-estrogens are also able to inhibit the terminal maturation of DC. By inhibiting the functional differentiation of DC, anti-estrogens may have a role in the treatment and prevention of autoimmune diseases.
Collapse
|
345
|
Rincón M, Flavell RA, Davis RA. The JNK and P38 MAP kinase signaling pathways in T cell-mediated immune responses. Free Radic Biol Med 2000; 28:1328-37. [PMID: 10924852 DOI: 10.1016/s0891-5849(00)00219-7] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The mitogen-activated protein (MAP) kinase family members, which include the extracellular response kinases (ERK), p38, and c-Jun amino terminal kinases (JNK), play a role in mediating signals triggered by cytokines, growth factors, and environmental stress. JNK and p38 MAP kinases have been involved in inflammatory processes induced by a variety of stimuli, such as oxidative stress. Here, we describe the role of the JNK and p38 MAP kinase signaling pathways in the development of T cells in the thymus, and activation and differentiation of T cells in the peripheral immune system.
Collapse
Affiliation(s)
- M Rincón
- Immunobiology Program, Department of Medicine, University of Vermont, Burlington, VT 05405, USA.
| | | | | |
Collapse
|
346
|
Rincón M, Conze D, Weiss L, Diehl NL, Fortner KA, Yang D, Flavell RA, Enslen H, Whitmarsh A, Davis RJ. Conference highlight: do T cells care about the mitogen-activated protein kinase signalling pathways? Immunol Cell Biol 2000; 78:166-75. [PMID: 10762418 DOI: 10.1046/j.1440-1711.2000.00900.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mitogen-activated protein (MAP) kinases, which include the extracellular response kinases, p38 and c-Jun amino terminal kinases (JNK), play a significant role in mediating signals triggered by cytokines, growth factors and environmental stress. The JNK and p38 MAP kinases have been involved in growth, differentiation and cell death in different cell types. In the present paper, we describe how the JNK and p38 MAP kinase signalling pathways are regulated and their role during thymocyte development and the activation and differentiation of T cells in the peripheral immune system. The results from these studies demonstrate that the JNK and p38 MAP kinase signalling pathways regulate different aspects of T-cell mediated immune responses.
Collapse
Affiliation(s)
- M Rincón
- Immunobiology Program, Department of Medicine, University of Vermont, Burlington, Vermont 05405, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
347
|
Potapova O, Gorospe M, Dougherty RH, Dean NM, Gaarde WA, Holbrook NJ. Inhibition of c-Jun N-terminal kinase 2 expression suppresses growth and induces apoptosis of human tumor cells in a p53-dependent manner. Mol Cell Biol 2000; 20:1713-22. [PMID: 10669748 PMCID: PMC85354 DOI: 10.1128/mcb.20.5.1713-1722.2000] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/1999] [Accepted: 11/10/1999] [Indexed: 12/11/2022] Open
Abstract
c-Jun N-terminal kinase (JNK) plays a critical role in coordinating the cellular response to stress and has been implicated in regulating cell growth and transformation. To investigate the growth-regulatory functions of JNK1 and JNK2, we used specific antisense oligonucleotides (AS) to inhibit their expression. A survey of several human tumor cell lines revealed that JNKAS treatment markedly inhibited the growth of cells with mutant p53 status but not that of cells with normal p53 function. To further examine the influence of p53 on cell sensitivity to JNKAS treatment, we compared the responsiveness of RKO, MCF-7, and HCT116 cells with normal p53 function to that of RKO E6, MCF-7 E6, and HCT116 p53(-/-), which were rendered p53 deficient by different methods. Inhibition of JNK2 (and to a lesser extent JNK1) expression dramatically reduced the growth of p53-deficient cells but not that of their normal counterparts. JNK2AS-induced growth inhibition was correlated with significant apoptosis. JNK2AS treatment induced the expression of the cyclin-dependent kinase inhibitor p21(Cip1/Waf1) in parental MCF-7, RKO, and HCT116 cells but not in the p53-deficient derivatives. That p21(Cip1/Waf1) expression contributes to the survival of JNK2AS-treated cells was supported by additional experiments demonstrating that p21(Cip1/Waf1) deficiency in HCT116 cells also results in heightened sensitivity to JNKAS treatment. Our results indicate that perturbation of JNK2 expression adversely affects the growth of otherwise nonstressed cells. p53 and its downstream effector p21(Cip1/Waf1) are important in counteracting these detrimental effects and promoting cell survival.
Collapse
Affiliation(s)
- O Potapova
- Cell Stress and Aging Section, Laboratory of Biological Chemistry, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
| | | | | | | | | | | |
Collapse
|
348
|
Mitchison NA, Schuhbauer D, Müller B. Natural and induced regulation of Th1/Th2 balance. SPRINGER SEMINARS IN IMMUNOPATHOLOGY 2000; 21:199-210. [PMID: 10666769 DOI: 10.1007/bf00812253] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Because Th1/Th2 balance is perturbed during immunological disease, the design of strategies aiming at its rectification has become a priority. The alteration of the balance in pregnancy so as to promote survival of the fetal allograft lends credibility to this aim. Attenuation of the activation signal delivered through the T cell receptor (TCR) represents a promising approach. It is supported by the high level of polymorphism in the MHC class II promoter, which regulates the natural TCR signal and thus modulates Th1/Th2 differentiation. Further support comes from the Th2 shift that occurs in JNK knockout mice, and with kinase inhibitors and anti-CD4 monoclonal antibodies applied in vitro. The approach has implications for nasal tolerance and inhibition of IL-12 production. The further range of options for Th1/Th2 modulation, which are presented throughout this issue of the journal, are here summarised and evaluated.
Collapse
Affiliation(s)
- N A Mitchison
- Department of Immunology, University College London, Windeyer Institute of Medical Sciences, UK
| | | | | |
Collapse
|
349
|
Gene expressions of lipopolysaccharide receptors, toll-like receptors 2 and 4, are differently regulated in mouse T lymphocytes. Blood 2000. [DOI: 10.1182/blood.v95.4.1378.004k08_1378_1385] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Toll-like receptors (TLRs) are a family of mammalian proteins homologous to Drosophila Toll. Human TLR2 was shown to mediate the responsiveness to lipopolysaccharide (LPS). On the other hand, gene mutations of mouse TLR4 (mTLR4) in LPS-hyporesponsive strains have suggested that mTLR4 is essential for LPS-signaling in mice, but the role of mTLR2 has not been explored. This report describes molecular cloning of the mTLR2 cDNA. Overexpression of mTLR2 and mouse CD14 conferred LPS-inducibility of c-Jun N-terminal kinase phosphorylation and nuclear factor-κB activation to COS7 cells, suggesting that mTLR2 is a signaling receptor for LPS. BothmTLR2 and mTLR4 genes were expressed in T cells. Treatment with anti-CD3ɛ, PMA plus ionomycin, or interleukin-2 (IL-2)/IL-15 increased mTLR2 but not mTLR4 messenger RNA (mRNA) in some T cell lines. Specific inhibitors of mitogen-activated extracellular signal-regulated kinase and fusion protein 38 (p38) kinase inhibited mTLR2 mRNA up-regulation by PMA plus ionomycin. This suggests that extracellular signal-regulated kinase and p38 kinase pathways were involved. Additionally, LPS treatment of EL-4 cell line decreasedIL-4 gene expression. Our results indicate that both mTLR2 and mTLR4 are involved in LPS signaling, but their expressions are regulated differently in T cells, and that LPS may directly affect T-cell functions by binding to TLRs.
Collapse
|
350
|
Kelkar N, Gupta S, Dickens M, Davis RJ. Interaction of a mitogen-activated protein kinase signaling module with the neuronal protein JIP3. Mol Cell Biol 2000; 20:1030-43. [PMID: 10629060 PMCID: PMC85220 DOI: 10.1128/mcb.20.3.1030-1043.2000] [Citation(s) in RCA: 245] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The c-Jun NH(2)-terminal kinase (JNK) group of mitogen-activated protein kinases (MAPKs) is activated in response to the treatment of cells with inflammatory cytokines and by exposure to environmental stress. JNK activation is mediated by a protein kinase cascade composed of a MAPK kinase and a MAPK kinase kinase. Here we describe the molecular cloning of a putative molecular scaffold protein, JIP3, that binds the protein kinase components of a JNK signaling module and facilitates JNK activation in cultured cells. JIP3 is expressed in the brain and at lower levels in the heart and other tissues. Immunofluorescence analysis demonstrated that JIP3 was present in the cytoplasm and accumulated in the growth cones of developing neurites. JIP3 is a member of a novel class of putative MAPK scaffold proteins that may regulate signal transduction by the JNK pathway.
Collapse
Affiliation(s)
- N Kelkar
- Howard Hughes Medical Institute, Program in Molecular Medicine, Department of Biochemistry, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | | | | | | |
Collapse
|