151
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Lawendy N, Krishnaswami S, Wang R, Gruben D, Cannon C, Swan S, Chan G. Effect of CP-690,550, an orally active janus kinase inhibitor, on renal function in healthy adult volunteers. J Clin Pharmacol 2009; 49:423-9. [PMID: 19318693 DOI: 10.1177/0091270008330982] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
CP-690,550 is a Janus kinase inhibitor being developed to prevent allograft rejection and treat several autoimmune diseases. This study examines the effect of multiple doses of CP-690,550 on renal function in healthy volunteers. Thirty-four volunteers are randomized in a 2:1 ratio in a double-blinded manner to receive CP-690,550 15 mg twice daily or placebo twice daily for 14 days. Volunteers are confined in-house to receive a controlled regimen of water intake and sodium intake of 4 to 5 g/d. The effect of CP-690,550 on glomerular filtration rate (GFR) is measured by iohexol serum clearance, effective renal plasma flow (ERPF) by para-aminohippuric acid (PAH) urinary clearance, and creatinine clearance by 24-hour urine collection on day 1 (predose) and day 15. Steady-state pharmacokinetics and tolerability are assessed. Comparing the day 15 and day 1 (predose) values shows that geometric mean ratios for iohexol serum clearance, PAH urinary clearance, and creatinine clearance are 0.995, 0.925, and 0.948, respectively. When adjusted for the corresponding placebo day ratios, the geometric mean ratios are 1.09, 0.978, and 1.05, respectively. CP-690,550 is well tolerated. These findings indicate that CP-690,550 does not affect GFR, ERPF, or creatinine clearance in healthy volunteers.
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Affiliation(s)
- Nervin Lawendy
- Pfizer Inc, Global Research and Development, 50 Pequot Avenue, New London, CT 06320, USA
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152
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Pesu M, Laurence A, Kishore N, Zwillich SH, Chan G, O'Shea JJ. Therapeutic targeting of Janus kinases. Immunol Rev 2009; 223:132-42. [PMID: 18613833 DOI: 10.1111/j.1600-065x.2008.00644.x] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
SUMMARY Cytokines play pivotal roles in immunity and inflammation, and targeting cytokines and their receptors is an effective means of treating such disorders. Type I and II cytokine receptors associate with Janus family kinases (JAKs) to effect intracellular signaling. These structurally unique protein kinases play essential and specific roles in immune cell development and function. One JAK, JAK3, has particularly selective functions. Mutations of this kinase underlie severe combined immunodeficiency, indicative of its critical role in the development and function of lymphocytes. Because JAK3 appears not to have functions outside of hematopoietic cells, this kinase has been viewed as an excellent therapeutic target for the development of a new class of immunosuppressive drugs. In fact, several companies are developing JAK3 inhibitors, and Phase II studies are underway. Mutations of Tyk2 cause autosomal recessive hyperIgE syndrome, and in principle, Tyk2 inhibitors might also be useful as immunosuppressive drugs. JAK2 gain-of-function mutations (V617F) underlie a subset of disorders collectively referred to as myeloproliferative diseases and phase 2 trials using JAK inhibitors are underway in this setting. Thus, we are learning a great deal about the feasibility and effectiveness of targeting Janus kinases, and it appears likely that this will be a fruitful strategy in a variety of settings.
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Affiliation(s)
- Marko Pesu
- Molecular Immunology and Inflammation Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
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153
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Synthetic staurosporines via a ring closing metathesis strategy as potent JAK3 inhibitors and modulators of allergic responses. Bioorg Med Chem Lett 2009; 19:3333-8. [PMID: 19427203 DOI: 10.1016/j.bmcl.2009.04.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 04/02/2009] [Accepted: 04/07/2009] [Indexed: 11/20/2022]
Abstract
The synthesis and biological evaluation of JAK3 based staurosporine compounds is described. The compounds are constructed completely de novo, and a ring closing metathesis strategy is used to assemble the sugar mimetic portion. These analogs show potent JAK3 activity against isolated enzyme and in T-cells. One analog (32) showed unique biological effects during in vitro and in vivo tests including inhibition of STAT5 phosphorylation, blockade of mast cell responses, and reduction of JAK3 based effects in mice models of allergic disease.
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154
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Abstract
The Janus family kinases (Jaks), Jak1, Jak2, Jak3, and Tyk2, form one subgroup of the non-receptor protein tyrosine kinases. They are involved in cell growth, survival, development, and differentiation of a variety of cells but are critically important for immune cells and hematopoietic cells. Data from experimental mice and clinical observations have unraveled multiple signaling events mediated by Jaks in innate and adaptive immunity. Deficiency of Jak3 or Tyk2 results in defined clinical disorders, which are also evident in mouse models. A striking phenotype associated with inactivating Jak3 mutations is severe combined immunodeficiency syndrome, whereas mutation of Tyk2 results in another primary immunodeficiency termed autosomal recessive hyperimmunoglobulin E syndrome. By contrast, complete deletion of Jak1 or Jak2 in the mouse are not compatible with life and, unsurprisingly, do not have counterparts in human disease. However, activating mutations of each of the Jaks are found in association with malignant transformation, the most common being gain-of-function mutations of Jak2 in polycythemia vera and other myeloproliferative disorders. Our existing knowledge on Jak signaling pathways and fundamental work on their biochemical structure and intracellular interactions allow us to develop new strategies for controlling autoimmune diseases or malignancies by developing selective Jak inhibitors, which are now coming into clinical use. Despite the fact that Jaks were discovered only a little more than a decade ago, at the time of writing there are 20 clinical trials underway testing the safety and efficacy of Jak inhibitors.
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Affiliation(s)
- Kamran Ghoreschi
- Molecular Immunology and Inflammation Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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155
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Constitutive JAK3 activation induces lymphoproliferative syndromes in murine bone marrow transplantation models. Blood 2009; 113:2746-54. [PMID: 19139084 DOI: 10.1182/blood-2008-06-164368] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The tyrosine kinase JAK3 plays a well-established role during normal lymphocyte development and is constitutively phosphorylated in several lymphoid malignancies. However, its contribution to lymphomagenesis remains elusive. In this study, we used the newly identified activating JAK3A572V mutation to elucidate the effect of constitutive JAK3 signaling on murine lymphopoiesis. In a bone marrow transplantation model, JAK3A572V induces an aggressive, fatal, and transplantable lymphoproliferative disorder characterized by the expansion of CD8(+)TCRalphabeta(+)CD44(+)CD122(+)Ly-6C(+) T cells that closely resemble an effector/memory T-cell subtype. Compared with wild-type counterparts, these cells show increased proliferative capacities in response to polyclonal stimulation, enhanced survival rates with elevated expression of Bcl-2, and increased production of interferon-gamma (IFNgamma) and tumor necrosis factor-alpha (TNFalpha), correlating with enhanced cytotoxic abilities against allogeneic target cells. Of interest, the JAK3A572V disease is epidermotropic and produces intraepidermal microabscesses. Taken together, these clinical features are reminiscent of those observed in an uncommon but aggressive subset of CD8(+) human cutaneous T-cell lymphomas (CTCLs). However, we also observed a CD4(+) CTCL-like phenotype when cells are transplanted in an MHC-I-deficient background. These data demonstrate that constitutive JAK3 activation disrupts T-cell homeostasis and induces lymphoproliferative diseases in mice.
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156
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Minegishi Y, Karasuyama H. Defects in Jak-STAT-mediated cytokine signals cause hyper-IgE syndrome: lessons from a primary immunodeficiency. Int Immunol 2008; 21:105-12. [PMID: 19088064 DOI: 10.1093/intimm/dxn134] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- Yoshiyuki Minegishi
- Department of Immune Regulation, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
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157
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Sung JJ, Jeon J, Lee JJ, Kim CG. Zebrafish Jak2a plays a crucial role in definitive hematopoiesis and blood vessel formation. Biochem Biophys Res Commun 2008; 378:629-33. [PMID: 19059211 DOI: 10.1016/j.bbrc.2008.11.116] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Accepted: 11/19/2008] [Indexed: 11/18/2022]
Abstract
We examined the role of zebrafish (Danio rerio) Jak2a, a homolog of mammalian Jak2, in the developing embryo by injecting in vitro synthesized Jak2a shRNA into zebrafish zygotes. Blood circulation was suppressed in Jak2a shRNA-injected embryos from 24hours post fertilization (hpf) and all embryos died with enlarged pericardium, shortened body lengths, and defects in some vasculature within 8 days post fertilization. O-dianisidine staining of red blood cells revealed normal blood island formation with no circulating red blood cells. As in Jak2(-/-) transgenic mice, expression of definitive Ba1 globin was significantly reduced in Jak2a knockdown embryos at 36hpf, whereas expression of other hematopoietic markers, primitive be1 globin, gata-1, and scl, were unaffected. More importantly, blood vessel formation was disturbed in Jak2a knockdown embryos as revealed by alkaline phosphatase staining at 72hpf. Thus, our data indicate that zebrafish Jak2a is important in both definitive hematopoiesis and blood vessel formation.
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Affiliation(s)
- Jin Jea Sung
- Department of Life Science, College of Natural Sciences, Hanyang University, Haengdang 17, Sungdong-gu, Seoul 133-791, Republic of Korea
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158
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Abstract
Hyper-IgE syndrome (HIES) is a complex primary immunodeficiency characterized by high serum IgE, chronic eczematoid dermatitis, and recurrent extracellular bacterial infections. Two types of HIES have been reported: type 1 and type 2. Type 1 HIES displays abnormalities in multiple systems, including the skeletal, dental, and immune systems, whereas type 2 shows abnormalities confined to the immune system. We recently identified hypomorphic mutations in the signal transducer and activator of transcription 3 (STAT3) gene in type 1 HIES and a null mutation in the tyrosine kinase 2 (Tyk2) gene, accompanied by susceptibility to intracellular bacteria in type 2 HIES. Analyses of cytokine responses in both types of HIES revealed that severe defects in the signal transduction for multiple cytokines, including interleukin-6 and interleukin-23, are leading to impaired T-helper type 17 function. These findings suggest that HIES is caused by the defects in multiple cytokine signals and that the susceptibility to various infections in HIES is associated with the T-helper type 17 defect.
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Affiliation(s)
- Yoshiyuki Minegishi
- Department of Immune Regulation, Tokyo Medical and Dental University Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
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159
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Kim BH, Yin CH, Guo Q, Bach EA, Lee H, Sandoval C, Jayabose S, Ulaczyk-Lesanko A, Hall DG, Baeg GH. A small-molecule compound identified through a cell-based screening inhibits JAK/STAT pathway signaling in human cancer cells. Mol Cancer Ther 2008; 7:2672-80. [PMID: 18790749 DOI: 10.1158/1535-7163.mct-08-0309] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Inappropriate activation of JAK/STAT signaling occurs with high frequency in human cancers and is associated with cancer cell survival and proliferation. Therefore, the development of pharmacologic STAT signaling inhibitors has therapeutic potential in the treatment of human cancers. Here, we report 2-[(3,5-bis-trifluoromethyl-phenyl)-hydroxy-methyl]-1-(4-nitro-phenylamino)-6-phenyl-1,2,4a,7a-tetrahydro-pyrrolo[3,4-b]-pyridine-5,7-dione (AUH-6-96) as a novel small-molecule inhibitor of JAK/STAT signaling that we initially identified through a cell-based high-throughput screening using cultured Drosophila cells. Treatment of Drosophila cells with AUH-6-96 resulted in a reduction of Unpaired-induced transcriptional activity and tyrosine phosphorylation of STAT92E, the sole Drosophila STAT homologue. In human cancer cell lines, AUH-6-96 inhibited both constitutive and interleukin-6-induced STAT3 phosphorylation. Specifically, in Hodgkin lymphoma L540 cells, treatment with AUH-6-96 resulted in reduced levels of tyrosine phosphorylated STAT3 and of the STAT3 downstream target gene SOCS3 in a dose- and time-dependent manner. In addition, AUH-6-96-treated L540 cells showed decreased expression of persistently activated JAK3, suggesting that AUH-6-96 inhibits the JAK/STAT pathway signaling in L540 cells by affecting JAK3 activity and subsequently blocking STAT3 signaling. Importantly, AUH-6-96 selectively affected cell viability only of cancer cells harboring aberrant JAK/STAT signaling. In support of the specificity of AUH-6-96 for inhibition of JAK/STAT signaling, treatment with AUH-6-96 decreased cancer cell survival by inducing programmed cell death by down-regulating the expression of STAT3 downstream target antiapoptotic genes, such as Bcl-xL. In summary, this study shows that AUH-6-96 is a novel small-molecule inhibitor of JAK/STAT signaling and may have therapeutic potential in the treatment of human cancers harboring aberrant JAK/STAT signaling.
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Affiliation(s)
- Byung Hak Kim
- Department of Pediatrics, Division of Hematology/Oncology, New York Medical College, Valhalla, NY 10595, USA
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160
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Impaired survival of peripheral T cells, disrupted NK/NKT cell development, and liver failure in mice lacking Gimap5. Blood 2008; 112:4905-14. [PMID: 18796632 DOI: 10.1182/blood-2008-03-146555] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The loss of Gimap5 (GTPase of the immune-associated protein 5) gene function is the underlying cause of lymphopenia and autoimmune diabetes in the BioBreeding (BB) rat. The in vivo function of murine gimap5 is largely unknown. We show that selective gene ablation of the mouse gimap5 gene impairs the final intrathymic maturation of CD8 and CD4 T cells and compromises the survival of postthymic CD4 and CD8 cells, replicating findings in the BB rat model. In addition, gimap5 deficiency imposes a block of natural killer (NK)- and NKT-cell differentiation. Development of NK/NKT cells is restored on transfer of gimap5(-/-) bone marrow into a wild-type environment. Mice lacking gimap5 have a median survival of 15 weeks, exhibit chronic hepatic hematopoiesis, and in later stages show pronounced hepatocyte apoptosis, leading to liver failure. This pathology persists in a Rag2-deficient background in the absence of mature B, T, or NK cells and cannot be adoptively transferred by transplanting gimap5(-/-) bone marrow into wild-type recipients. We conclude that mouse gimap5 is necessary for the survival of peripheral T cells, NK/NKT-cell development, and the maintenance of normal liver function. These functions involve cell-intrinsic as well as cell-extrinsic mechanisms.
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161
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Johnson SE, Shah N, Bajer AA, LeBien TW. IL-7 activates the phosphatidylinositol 3-kinase/AKT pathway in normal human thymocytes but not normal human B cell precursors. THE JOURNAL OF IMMUNOLOGY 2008; 180:8109-17. [PMID: 18523275 DOI: 10.4049/jimmunol.180.12.8109] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
IL-7 signaling culminates in different biological outcomes in distinct lymphoid populations, but knowledge of the biochemical signaling pathways in normal lymphoid populations is incomplete. We analyzed CD127/IL-7Ralpha expression and function in normal (nontransformed) human thymocytes, and human CD19(+) B-lineage cells purified from xenogeneic cord blood stem cell/MS-5 murine stromal cell cultures, to further clarify the role of IL-7 in human B cell development. IL-7 stimulation of CD34(+) immature thymocytes led to phosphorylation (p-) of STAT5, ERK1/2, AKT, and glycogen synthase kinase-3 beta, and increased AKT enzymatic activity. In contrast, IL-7 stimulation of CD34(-) thymocytes (that included CD4(+)/CD8(+) double-positive, and CD4(+) and CD8(+) single-positive cells) only induced p-STAT5. IL-7 stimulation of CD19(+) cells led to robust induction of p-STAT5, but minimal induction of p-ERK1/2 and p-glycogen synthase kinase-3 beta. However, CD19(+) cells expressed endogenous p-ERK1/2, and when rested for several hours following removal from MS-5 underwent de-phosphorylation of ERK1/2. IL-7 stimulation of rested CD19(+) cells resulted in robust induction of p-ERK1/2, but no induction of AKT enzymatic activity. The use of a specific JAK3 antagonist demonstrated that all IL-7 signaling pathways in CD34(+) thymocytes and CD19(+) B-lineage cells were JAK3-dependent. We conclude that human CD34(+) thymocytes and CD19(+) B-lineage cells exhibit similarities in activation of STAT5 and ERK1/2, but differences in activation of the PI3K/AKT pathway. The different induction of PI3K/AKT may at least partially explain the different requirements for IL-7 during human T and B cell development.
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Affiliation(s)
- Sonja E Johnson
- The Masonic Cancer Center and Department of Laboratory Medicine/Pathology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
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162
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Wilks AF. The JAK kinases: not just another kinase drug discovery target. Semin Cell Dev Biol 2008; 19:319-28. [PMID: 18721891 DOI: 10.1016/j.semcdb.2008.07.020] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Accepted: 07/28/2008] [Indexed: 11/19/2022]
Abstract
There are four members of the JAK family of protein tyrosine kinases (PTKs) in the human genome. Since their discovery in 1989, great strides have been made in the understanding of their role in normal intracellular signalling. Importantly, their roles in pathologies ranging from cancer to immune deficiencies have placed them front and centre as potential drug targets. The recent discovery of the role of activating mutations in the kinase-like domain (KLD) of JAK2 in the development of polycythemia rubra vera, and the elaboration of KLD mutation as a broader mechanism by which cells might become hyperproliferative has sparked enormous interest in the development of JAK selective drug candidates. I review herein the progress that has been made in the discovery of JAK-targeted inhibitors, and discuss the challenges that face the development of these drugs for use in the clinic.
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Affiliation(s)
- Andrew F Wilks
- SYN|thesis med chem, PO Box 450, South Yarra, Victoria 3141, Australia.
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163
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Construction and application of an avian intestinal intraepithelial lymphocyte cDNA microarray (AVIELA) for gene expression profiling during Eimeria maxima infection. Vet Immunol Immunopathol 2008; 124:341-54. [DOI: 10.1016/j.vetimm.2008.04.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Revised: 04/14/2008] [Accepted: 04/22/2008] [Indexed: 11/19/2022]
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164
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Abstract
Characterization of how interferons (IFNs) mediate their biological response led to identification of the JAK-STAT signaling cascade, where JAKs are receptor-associated kinases and STATs the transcription factors they activate. Today, 4 JAKs and 7 STATs are known to transduce pivotal signals for the over 50 members of the four-helix bundle family of cytokines. This review will provide an overview and historical perspective of the JAK-STAT paradigm.
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165
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O'Shea JJ, Johnston JA, Kehrl J, Koretzky G, Samelson LE. Key molecules involved in receptor-mediated lymphocyte activation. ACTA ACUST UNITED AC 2008; Chapter 11:Unit 11.9A. [PMID: 18432708 DOI: 10.1002/0471142735.im1109as44] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This unit, along with Unit 11.9B, provides a summary of our current knowledge about various signaling pathways critical to the function of immune cells. Here, our understanding of T cell receptor (TCR)- and B cell receptor (BCR)-mediated signaling is summarized. A schematic representation of immunologically relevant cytokine receptors and the Janus Family Kinases (JAKs) that is activated through these receptors is provided, along with details about molecules involved in interleukin 2 mediated signal transduction.
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Affiliation(s)
- J J O'Shea
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, Maryland, USA
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166
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Walz C, Cross NCP, Van Etten RA, Reiter A. Comparison of mutated ABL1 and JAK2 as oncogenes and drug targets in myeloproliferative disorders. Leukemia 2008; 22:1320-34. [PMID: 18528425 PMCID: PMC3490192 DOI: 10.1038/leu.2008.133] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 04/24/2008] [Accepted: 04/25/2008] [Indexed: 01/17/2023]
Abstract
Constitutively activated mutants of the non-receptor tyrosine kinases (TK) ABL1 (Abelson murine leukemia viral (v-abl) homolog (1) protein) and JAK2 (JAnus Kinase 2 or Just Another Kinase 2) play a central role in the pathogenesis of clinically and morphologically distinct chronic myeloproliferative disorders but are also found in some cases of de novo acute leukemia and lymphoma. Ligand-independent activation occurs as a consequence of point mutations or insertions/deletions within functionally relevant regulatory domains (JAK2) or the creation of TK fusion proteins by balanced reciprocal translocations, insertions or episomal amplification (ABL1 and JAK2). Specific abnormalities are correlated with clinical phenotype, although some are broad and encompass several World Health Organization-defined entities. TKs are excellent drug targets as exemplified by the activity of imatinib in BCR-ABL1-positive disease, particularly chronic myeloid leukemia. Resistance to imatinib is seen in a minority of cases and is often associated with the appearance of secondary point mutations within the TK domain of BCR-ABL1. These mutations are highly variable in their sensitivity to increased doses of imatinib or alternative TK inhibitors such as nilotinib or dasatinib. Selective and non-selective inhibitors of JAK2 are currently being developed, and encouraging data from pre-clinical experiments and initial phase-I studies regarding efficacy and potential toxicity of these compounds have already been reported.
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Affiliation(s)
- Christoph Walz
- Molecular Oncology Research Institute, Tufts Medical Center, Boston, MA, USA
| | - Nicholas C. P. Cross
- Wessex Regional Genetics Laboratory, Salisbury and Human Genetics Division, University of Southampton, U.K
| | | | - Andreas Reiter
- III. Medizinische Universitätsklinik, Medizinische Fakultät Mannheim der Universität Heidelberg, Germany
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167
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Requirement of TLR2-mediated signaling for the induction of IL-15 gene expression in human monocytic cells by HSV-1. Blood 2008; 112:2360-8. [PMID: 18583567 DOI: 10.1182/blood-2008-02-137711] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Exposure of human monocytic cells to herpes simplex virus type 1 (HSV-1) results in immediate up-regulation of interleukin (IL)-15 gene expression. However, the receptor involved in this induction is not known. Here, we provide evidence that this induction depends on TLR2-mediated signaling pathway. Through the use of small interfering RNAs (siRNAs), we demonstrate that HSV-1-induced up-regulation of IL-15 gene expression in monocytic THP1 cells requires the presence of the adaptors MyD88, IRAK1, and TRAF6. Interestingly, TIRAP/Mal, an adaptor molecule specifically recruited to TLR2 and TLR4, was also required for maximal up-regulation of IL-15. This response was completely abrogated by anti-TLR2, but not anti-TLR4, blocking mAbs in both primary monocytes and THP1 cells. Furthermore, THP1 cells rendered defective in TLR2 expression by disrupting the expression of Sp1, a major transcription factor involved in TLR2 promoter activity, were unable to up-regulate IL-15 gene expression in response to HSV-1. In addition, HSV-1-induced NF-kappaB activation was significantly reduced after neutralization of TLR2 and the adaptor proteins. Altogether, these results unequivocally show that HSV-1 induces TLR2-dependent activation of IL-15 gene expression, which requires the recruitment of both MyD88 and TIRAP/Mal and the activation of IRAK1 and TRAF6 leading to NF-kappaB translocation to the nucleus.
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168
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Mathew S, George SP, Wang Y, Siddiqui MR, Srinivasan K, Tan L, Khurana S. Potential molecular mechanism for c-Src kinase-mediated regulation of intestinal cell migration. J Biol Chem 2008; 283:22709-22. [PMID: 18482983 DOI: 10.1074/jbc.m801319200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The ubiquitously expressed Src tyrosine kinases (c-Src, c-Yes, and c-Fyn) regulate intestinal cell growth and differentiation. Src activity is also elevated in the majority of malignant and premalignant tumors of the colon. The development of fibroblasts with the three ubiquitously expressed kinases deleted (SYF cells) has identified the role of Src proteins in the regulation of actin dynamics associated with increased cell migration and invasion. Despite this, unexpectedly nothing is known about the role of the individual Src kinases on intestinal cell cytoskeleton and/or cell migration. We have previously reported that villin, an epithelial cell-specific actin-modifying protein that regulates actin reorganization, cell morphology, cell migration, cell invasion, and apoptosis, is tyrosine-phosphorylated. In this report using the SYF cells reconstituted individually with c-Src, c-Yes, c-Fyn, and wild type or phosphorylation site mutants of villin, we demonstrate for the first time the absolute requirement for c-Src in villin-induced regulation of cell migration. The other major finding of our study is that contrary to previous reports, the nonreceptor tyrosine kinase, Jak3 (Janus kinase 3), does not regulate phosphorylation of villin or villin-induced cell migration and is, in fact, not expressed in intestinal epithelial cells. Further, we identify SHP-2 and PTP-PEST (protein-tyrosine phosphatase proline-, glutamate-, serine-, and threonine-rich sequence) as negative regulators of c-Src kinase and demonstrate a new function for these phosphatases in intestinal cell migration. Together, these data suggest that in colorectal carcinogenesis, elevation of c-Src or down-regulation of SHP-2 and/or PTP-PEST may promote cancer metastases and invasion by regulating villin-induced cell migration and cell invasion.
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Affiliation(s)
- Sijo Mathew
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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169
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Abstract
The Janus family of non-receptor tyrosine kinases (JAK1, JAK2, JAK3 and tyrosine kinase 2) transduces signals downstream of type I and II cytokine receptors via signal transducers and activators of transcription (STATs). JAK3 is important in lymphoid and JAK2 in myeloid cell proliferation and differentiation. The thrombopoietin receptor MPL is one of several JAK2 cognate receptors and is essential for myelopoiesis in general and megakaryopoiesis in particular. Germline loss-of-function (LOF) JAK3 and MPL mutations cause severe combined immunodeficiency and congenital amegakaryocytic thrombocytopenia, respectively. Germline gain-of-function (GOF) MPL mutation (MPLS505N) causes familial thrombocytosis. Somatic JAK3 (e.g. JAK3A572V, JAK3V722I, JAK3P132T) and fusion JAK2 (e.g. ETV6-JAK2, PCM1-JAK2, BCR-JAK2) mutations have respectively been described in acute megakaryocytic leukemia and acute leukemia/chronic myeloid malignancies. However, current attention is focused on JAK2 (e.g. JAK2V617F, JAK2 exon 12 mutations) and MPL (e.g. MPLW515L/K/S, MPLS505N) mutations associated with myeloproliferative neoplasms (MPNs). A JAK2 mutation, primarily JAK2V617F, is invariably associated with polycythemia vera (PV). The latter mutation also occurs in the majority of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). MPL mutational frequency in MPNs is substantially less (<10%). In general, despite a certain degree of genotype - phenotype correlations, the prognostic relevance of harbouring one of these mutations, or their allele burden when present, remains dubious. Regardless, based on the logical assumption that amplified JAK-STAT signalling is central to the pathogenesis of PV, ET and PMF, several anti-JAK2 tyrosine kinase inhibitors have been developed and are currently being tested in humans with these disorders.
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Affiliation(s)
- Ayalew Tefferi
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
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170
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Contributions of the Raf/MEK/ERK, PI3K/PTEN/Akt/mTOR and Jak/STAT pathways to leukemia. Leukemia 2008; 22:686-707. [DOI: 10.1038/leu.2008.26] [Citation(s) in RCA: 293] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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171
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Abstract
B-cell development is orchestrated by complex signaling networks. Rap1 is a member of the Ras superfamily of small GTP-binding proteins and has 2 isoforms, Rap1a and Rap1b. Although Rap1 has been suggested to have an important role in a variety of cellular processes, no direct evidence demonstrates a role for Rap1 in B-cell biology. In this study, we found that Rap1b was the dominant isoform of Rap1 in B cells. We discovered that Rap1b deficiency in mice barely affected early development of B cells but markedly reduced marginal zone (MZ) B cells in the spleen and mature B cells in peripheral and mucosal lymph nodes. Rap1b-deficient B cells displayed normal survival and proliferation in vivo and in vitro. However, Rap1b-deficient B cells had impaired adhesion and reduced chemotaxis in vitro, and lessened homing to lymph nodes in vivo. Furthermore, we found that Rap1b deficiency had no marked effect on LPS-, BCR-, or SDF-1-induced activation of mitogen-activated protein kinases and AKT but clearly impaired SDF-1-mediated activation of Pyk-2, a key regulator of SDF-1-mediated B-cell migration. Thus, we have discovered a critical and distinct role of Rap1b in mature B-cell trafficking and development of MZ B cells.
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172
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STAT5 requires the N-domain to maintain hematopoietic stem cell repopulating function and appropriate lymphoid-myeloid lineage output. Exp Hematol 2008; 35:1684-94. [PMID: 17976521 DOI: 10.1016/j.exphem.2007.08.026] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Revised: 08/20/2007] [Accepted: 08/20/2007] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Signal transducer and activator of transcription 5 (STAT5) is a critical regulator of hematopoietic development and its impaired activation is associated with hematopoietic and immune cell defects. However, much of this information has been learned from knockout mice that still retain the potential for expression of STAT5 proteins that are N-terminally truncated due to alternative internal translation initiation codons. The goal of these studies was to use transplantation-based assays to analyze the degree of STAT5 deltaN activity in hematopoietic stem cells (HSC) and throughout lymphomyeloid development. METHODS We have directly compared E14.5 fetal liver cells from mice with potential to express STAT5ab deltaN (STAT5ab(deltaN/deltaN)) with mice completely lacking STAT5a and STAT5b (STAT5abnull/null). We have also utilized retroviral complementation of STAT5abnull/null fetal liver HSC to enforce expression of full-length STAT5a or STAT5a lacking the first 136 amino acids (STAT5a deltaN). RESULTS We report that STAT5 is required for HSC, lymphocyte, and erythrocyte development. We demonstrate that restored expression of STAT5a in STAT5abnull/null HSC provides a strong selective advantage, correcting T- and B-lymphocyte and erythrocyte development. Interestingly, Gr-1(+) blood cells were inversely correlated with B lymphocytes and both were normalized by STAT5a expression. In contrast, transduction of STAT5a deltaN only provided partial B-lymphocyte development. CONCLUSIONS These studies define the role of STAT5 in maintaining normal lymphoid vs myeloid balance during hematopoiesis and highlight a major role for the N-domain in HSC function. The platform of retroviral complementation described here will be particularly useful for future studies to subdefine the N-domain regions that are critical for hematopoiesis.
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173
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Huntington ND, Di Santo JP. Humanized immune system (HIS) mice as a tool to study human NK cell development. Curr Top Microbiol Immunol 2008; 324:109-24. [PMID: 18481456 DOI: 10.1007/978-3-540-75647-7_7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The study of human hematopoiesis is conditioned by access to nondiseased human tissue samples that harbor the cellular substrates for this developmental process. Technical and ethical concerns limit the availability to tissues derived from the fetal and newborn periods, while adult samples are generally restricted to peripheral blood. Access to a small animal model that faithfully recapitulates the process of human hematopoiesis would provide an important tool. Natural killer (NK) cells comprise between 10% and 15% of human peripheral blood lymphocytes and appear conserved in several species. NK cells are implicated in the recognition of pathogen-infected cells and in the clearance of certain tumor cells. In this chapter, we discuss NK cell developmental pathways and the use of humanized murine models for the study of human hematopoiesis and, in particular, human NK cell development.
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Affiliation(s)
- N D Huntington
- Cytokine and Lymphoid Development Unit, Immunology Department, Institut Pasteur, 25 rue du Docteur Roux, Paris 75724, France
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174
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Soldevila G, García-Zepeda EA. The role of the Jak-Stat pathway in chemokine-mediated signaling in T lymphocytes. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/sita.200700144] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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175
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Chaudhry UI, Plitas G, Burt BM, Kingham TP, Raab JR, DeMatteo RP. NK dendritic cells expanded in IL-15 exhibit antitumor responses in vivo. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2007; 179:4654-60. [PMID: 17878363 DOI: 10.4049/jimmunol.179.7.4654] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
NK dendritic cells (NKDC) are a novel subtype of DC with NK cell properties. IL-15 is a pleiotropic cytokine that plays an obligate role in the proliferation and survival of NK cells. We hypothesized that IL-15 is also essential for NKDC development. NKDC were nearly absent in IL-15(-/-) mice, but restored by administration of exogenous IL-15. Treatment of wild-type mice with IL-15 caused a 2- to 3-fold expansion of both NK cells and NKDC. After 7 days of culture with IL-15, sorted splenic NKDC expanded 10-fold while NK cells increased 5-fold. NKDC expanded in IL-15 retained their cytolytic capacity but lost the ability to stimulate naive T cells. Meanwhile, NKDC expanded in IL-15 produced 10 times more IFN-gamma as fresh NKDC and conferred protection in a tumor prevention model. Thus, IL-15 is essential to the proliferation and survival of NKDC and IL-15 expanded NKDC possess antitumor properties.
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Affiliation(s)
- Umer I Chaudhry
- Hepatobiliary Service, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
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176
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Pardanani A. JAK2 inhibitor therapy in myeloproliferative disorders: rationale, preclinical studies and ongoing clinical trials. Leukemia 2007; 22:23-30. [PMID: 17882282 DOI: 10.1038/sj.leu.2404948] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The recent identification of somatic mutations such as JAK2V617F that deregulate Janus kinase (JAK)-signal transducer and activator of transcription signaling has spurred development of orally bioavailable small-molecule inhibitors that selectively target JAK2 kinase as an approach to pathogenesis-directed therapy of myeloproliferative disorders (MPD). In pre-clinical studies, these compounds inhibit JAK2V617F-mediated cell growth at nanomolar concentrations, and in vivo therapeutic efficacy has been demonstrated in mouse models of JAK2V617F-induced disease. In addition, ex vivo growth of progenitor cells from MPD patients harboring JAK2V617F or MPLW515L/K mutations is also potently inhibited. JAK2 inhibitors currently in clinical trials can be grouped into those designed to primarily target JAK2 kinase (JAK2-selective) and those originally developed for non-MPD indications, but that nevertheless have significant JAK2-inhibitory activity (non-JAK2 selective). This article discusses the rationale for using JAK2 inhibitors for the treatment of MPD, as well as relevant aspects of clinical trial development for these patients. For instance, which group of MPD patients is appropriate for initial Phase I studies? Should JAK2V617F-negative MPD patients be included in the initial studies? What are the likely consequences of 'off-target' JAK3 and wild-type JAK2 inhibition? How should treatment responses be monitored?
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Affiliation(s)
- A Pardanani
- Division of Hematology and Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA.
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177
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Dai X, Chen Y, Di L, Podd A, Li G, Bunting KD, Hennighausen L, Wen R, Wang D. Stat5 is essential for early B cell development but not for B cell maturation and function. THE JOURNAL OF IMMUNOLOGY 2007; 179:1068-79. [PMID: 17617599 DOI: 10.4049/jimmunol.179.2.1068] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The two closely related Stat5 (Stat5A and Stat5B) proteins are activated by a broad spectrum of cytokines. However, with the complication of the involvement of Stat5A/5B in stem cell function, the role of Stat5A/5B in the development and function of lymphocytes, especially B cells, is not fully understood. In this study, we demonstrated that Stat5A/5B(-/-) fetal liver cells had severe diminution of B cell progenitors but clearly had myeloid progenitors. Consistently, the mutant fetal liver cells could give rise to hemopoietic progenitors and myeloid cells but not B cells beyond pro-B cell progenitors in lethally irradiated wild-type or Jak3(-/-) mice. Deletion of Stat5A/5B in vitro directly impaired IL-7-mediated B cell expansion. Of note, reintroduction of Stat5A back into Stat5A/5B(-/-) fetal liver cells restored their abilities to develop B cells. Importantly, CD19-Cre-mediated deletion of Stat5A/5B in the B cell compartment specifically impaired early B cell development but not late B cell maturation. Moreover, the B cell-specific deletion of Stat5A/5B did not impair splenic B cell survival, proliferation, and Ig production. Taken together, these data demonstrate that Stat5A/5B directly control IL-7-mediated early B cell development but are not required for B cell maturation and Ig production.
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Affiliation(s)
- Xuezhi Dai
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, People's Republic of China
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178
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Kittipatarin C, Khaled AR. Interlinking interleukin-7. Cytokine 2007; 39:75-83. [PMID: 17768066 PMCID: PMC2040031 DOI: 10.1016/j.cyto.2007.07.183] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 07/16/2007] [Accepted: 07/17/2007] [Indexed: 01/31/2023]
Abstract
The signaling processes that maintain the homeostatic proliferation of peripheral T-cells and result in their self-renewal largely remain to be elucidated. Much focus has been placed on the anti-apoptotic function of the cytokine, interleukin-7 (IL-7), during T-cell development. But a more critical role has been ascribed to IL-7 as a mediator of peripheral T-cell maintenance. The biological effects responsive to IL-7 signaling are transduced through only a few well-known pathways. In this review we will focus on the signals transduced by IL-7 and similar cytokines, examining how proliferative signals originate from cytokine receptors, are amplified and eventually alter gene expression. In this regard we will highlight the crosstalk between pathways that promote survival, drive cell cycle progression and most importantly provide the needed energy to sustain these critical cellular activities. Though this review showcases much of what has been learned about IL-7 proliferative signaling, it also reveals the significant gaps in our knowledge about cytokine signaling in the very relevant context of peripheral T-cell homeostasis.
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Affiliation(s)
- Christina Kittipatarin
- Biomolecular Science Center, University of Central Florida, 12722 Research Parkway, Orlando, FL 32826, USA
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179
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Taguchi T, Takenouchi H, Shiozawa Y, Matsui J, Kitamura N, Miyagawa Y, Katagiri YU, Takahashi T, Okita H, Fujimoto J, Kiyokawa N. Interleukin-7 contributes to human pro–B-cell development in a mouse stromal cell–dependent culture system. Exp Hematol 2007; 35:1398-407. [PMID: 17656007 DOI: 10.1016/j.exphem.2007.05.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Revised: 05/10/2007] [Accepted: 05/31/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVE The role of interleukin (IL)-7 in human B lymphopoiesis is still controversial. We used an in vitro culture system to verify involvement of IL-7 in development of human pro-B cells from hematopoietic stem cells. MATERIALS AND METHODS Human CD34(+) bone marrow cells were cultured for 4 weeks on MS-5 mouse stromal cells to induce pro-B cells. Expression of IL-7 receptor alpha or other B-cell differentiation marker genes on cultured human CD34(+)bone marrow cells was investigated by reverse transcription polymerase chain reaction (RT-PCR). Colony assay of human CD34(+) bone marrow cells was also performed to determine the effect of IL-7 on colony-forming ability. Neutralizing antibody or reagent that eliminates the effect of IL-7 was added to the culture system, and the number of pro-B cells induced was estimated by flow cytometry. RESULTS RT-PCR analysis revealed mRNA expression of IL-7 receptor alpha as well as B-cell differentiation marker genes in not only CD19(+) pro-B cells but also CD19(-) CD33(-) cells induced from CD34(+) bone marrow cells after cultivation for 4 weeks on MS-5 cells. Addition of anti-mouse IL-7 antibody, anti-human IL-7 receptor alpha antibody, or JAK3 kinase inhibitor reduced the number of pro-B cells induced, demonstrating that elimination of IL-7 reduces pro-B-cell development. Addition of anti-mouse IL-7 antibody emphasized the colony-forming ability of burst-forming unit erythroid cells. CONCLUSIONS IL-7 produced by MS-5 cells is required for human pro-B-cell development from CD34(+)bone marrow cells in our culture system, and IL-7 appears to play a certain role in early human B lymphopoiesis.
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Affiliation(s)
- Tomoko Taguchi
- Department of Developmental Biology, National Research Institute for Child Health and Development, Setagaya-ku, Tokyo, Japan
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180
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Shide K, Shimoda K, Kamezaki K, Kakumitsu H, Kumano T, Numata A, Ishikawa F, Takenaka K, Yamamoto K, Matsuda T, Harada M. Tyk2 mutation homologous to V617F Jak2 is not found in essential thrombocythaemia, although it induces constitutive signaling and growth factor independence. Leuk Res 2007; 31:1077-84. [PMID: 17011030 DOI: 10.1016/j.leukres.2006.08.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 08/01/2006] [Accepted: 08/26/2006] [Indexed: 10/24/2022]
Abstract
A single somatic mutation, V617F, in the pseudokinase domain of the Jak2 is the primary cause of many chronic myeloproliferative diseases. As valine 617 of Jak2 is conserved as valine 678 of Tyk2, we examined the effect of a homologous mutation in Tyk2 (V678F Tyk2) on cell growth. V678F Tyk2 augmented the transcriptional activity of Stat3 and Stat5. The expression of V678F Tyk2 in Ba/F3 cells induced autonomous cell growth and showed hyper-responsiveness to IL-3. Although V678F Tyk2 might cause MPD, no cases of ET patients lacking the V617F Jak2 mutation harbored the Tyk2 mutation.
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Affiliation(s)
- Kotaro Shide
- The First Department of Internal Medicine, Kyushu University Hospital, 3-1-1 Maidashi, Fukuoka, Fukuoka, Japan
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181
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Egawa T, Tillman RE, Naoe Y, Taniuchi I, Littman DR. The role of the Runx transcription factors in thymocyte differentiation and in homeostasis of naive T cells. ACTA ACUST UNITED AC 2007; 204:1945-57. [PMID: 17646406 PMCID: PMC2118679 DOI: 10.1084/jem.20070133] [Citation(s) in RCA: 236] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Members of the Runx family of transcriptional regulators are required for the appropriate expression of CD4 and CD8 at discrete stages of T cell development. The roles of these factors in other aspects of T cell development are unknown. We used a strategy to conditionally inactivate the genes encoding Runx1 or Runx3 at different stages of thymocyte development, demonstrating that Runx1 regulates the transitions of developing thymocytes from the CD4−CD8− double-negative stage to the CD4+CD8+ double-positive (DP) stage and from the DP stage to the mature single-positive stage. Runx1 and Runx3 deficiencies caused marked reductions in mature thymocytes and T cells of the CD4+ helper and CD8+ cytotoxic T cell lineages, respectively. Runx1-deficient CD4+ T cells had markedly reduced expression of the interleukin 7 receptor and exhibited shorter survival. In addition, inactivation of both Runx1 and Runx3 at the DP stages resulted in a severe block in development of CD8+ mature thymocytes. These results indicate that Runx proteins have important roles at multiple stages of T cell development and in the homeostasis of mature T cells.
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Affiliation(s)
- Takeshi Egawa
- Molecular Pathogenesis Program, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA
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182
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Huntington ND, Puthalakath H, Gunn P, Naik E, Michalak EM, Smyth MJ, Tabarias H, Degli-Esposti MA, Dewson G, Willis SN, Motoyama N, Huang DCS, Nutt SL, Tarlinton DM, Strasser A. Interleukin 15-mediated survival of natural killer cells is determined by interactions among Bim, Noxa and Mcl-1. Nat Immunol 2007; 8:856-63. [PMID: 17618288 PMCID: PMC2951739 DOI: 10.1038/ni1487] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Accepted: 06/14/2007] [Indexed: 12/30/2022]
Abstract
Interleukin 15 (IL-15) promotes the survival of natural killer (NK) cells by preventing apoptosis through mechanisms unknown at present. Here we identify Bim, Noxa and Mcl-1 as key regulators of IL-15-dependent survival of NK cells. IL-15 suppressed apoptosis by limiting Bim expression through the kinases Erk1 and Erk2 and mechanisms dependent on the transcription factor Foxo3a, while promoting expression of Mcl-1, which was necessary and sufficient for the survival of NK cells. Withdrawal of IL-15 led to upregulation of Bim and, accordingly, both Bim-deficient and Foxo3a-/- NK cells were resistant to cytokine deprivation. Finally, IL-15-mediated inactivation of Foxo3a and cell survival were dependent on phosphotidylinositol-3-OH kinase. Thus, IL-15 regulates the survival of NK cells at multiple steps, with Bim and Noxa being key antagonists of Mcl-1, the critical survivor factor in this process.
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Affiliation(s)
- Nicholas D Huntington
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia.
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183
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Cytokine signaling to the cell cycle. Immunol Res 2007; 39:173-84. [DOI: 10.1007/s12026-007-0080-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 10/23/2022]
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184
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García-Zepeda EA, Licona-Limón I, Jiménez-Sólomon MF, Soldevila G. Janus kinase 3-deficient T lymphocytes have an intrinsic defect in CCR7-mediated homing to peripheral lymphoid organs. Immunology 2007; 122:247-60. [PMID: 17521370 PMCID: PMC2266000 DOI: 10.1111/j.1365-2567.2007.02634.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Chemokine-mediated signalling involves the activation of a Janus kinase (Jak) pathway. We have previously shown that Jak3 mediates CCR9 and CXCR4 signalling in response to CCL25 and CXCL12 in BM progenitors and thymocytes. The lack of peripheral lymph nodes and Peyer's patches observed in Jak3(-/-) mice suggested a possible role of Jak3 in CCR7-mediated homing to these organs. Here, we demonstrate phosphorylation of Jak3 in peripheral lymphocytes in response CCL19 and CCL21. In addition, Jak3(-/-) naïve T cells and pharmacologically inhibited Jak3(+/+) T lymphocytes have impaired chemotactic responses towards these ligands. Interestingly, CCR7 expression was higher in Jak3(-/-) thymocytes compared to their Jak3(+)(/-) littermates, indicating that the impaired migration must be caused by impaired CCR7-mediated signalling, in the absence of Jak3. In addition, adoptive transfer experiments showed that Jak3(+/+) mice reconstituted with Jak3(-/-) green fluorescent protein (GFP)(+) bone marrow progenitors had reduced T-lymphocyte homing to peripheral and mesenteric lymph nodes, compared to reconstitution with Jak3(+/+) GFP(+) progenitors. Furthermore, reciprocal transfer experiments indicated that Jak3(-/-) stromal cells were not responsible for the deficient T-cell homing. Finally, we performed direct competitive homing assays and demonstrated that Jak3(-/-) T lymphocytes have a clear defect in homing to peripheral and mesenteric lymph nodes, while migration to spleen was moderately impaired. Our data demonstrates that Jak3(-/-) T lymphocytes have an intrinsic defect in CCR7-mediated homing to peripheral lymphoid organs.
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Affiliation(s)
- Eduardo A García-Zepeda
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas., Universidad Nacional Autónoma de México, México
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185
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Sur R, Cavender D, Malaviya R. Different approaches to study mast cell functions. Int Immunopharmacol 2007; 7:555-67. [PMID: 17386403 DOI: 10.1016/j.intimp.2007.01.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2006] [Accepted: 01/17/2007] [Indexed: 11/20/2022]
Abstract
Mast cells have long been known to play a detrimental role in the pathogenesis of IgE-associated allergic disorders by their ability to release a wide variety of pro-inflammatory mediators. A number of studies, however, have demonstrated that mast cells play a beneficial role in innate host defense against bacterial infections. Since mast cells clearly play both physiological and pathophysiological functions in the body, it is important to learn about the components of mast cells that drive these responses. The functional roles of mast cell in vivo have been principally characterized by comparing the biological responses in mast cell-deficient mice (WBB6F(1)-W/W(v)), their normal wild-type littermates (WBB6F(1)-+/+) and mast cell deficient mice reconstituted locally or systemically with mast cells cultured from the bone marrow cells of WBB6F(1)-+/+ mice (WBB6F(1)-W/W(v)+MC). Recently investigators have demonstrated that mast cell-deficient mice (WBB6F(1)-W/W(v)) can be reconstituted with mast cells derived in vitro from the bone marrow cells of certain gene knock-out mice or genetically-manipulated embryonic stem cells. This novel approach of analyzing the biological consequences of gene mutations in mast cells will help us to better understand the role of individual gene products in mast cell responses. In this review, we discuss these new approaches to investigate the functions of mast cells in vivo.
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Affiliation(s)
- Runa Sur
- Johnson & Johnson Pharmaceutical Research and Development, Raritan, NJ, USA
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186
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Abstract
Since the discovery of gammadelta T cells two decades ago, considerable effort has been made to understand their developmental program, their antigen specificity, and their contribution to the immune response. In this review, we focus on what is known about gammadelta T-cell development and on the advances that have been made in determining which genes are required. In addition, we compare the genetic requirements for alphabeta and gammadelta T-cell development with the hope of gaining a better picture of the signaling pathways that govern the development of gammadelta lineage cells.
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MESH Headings
- Animals
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cell Lineage/immunology
- Gene Rearrangement, delta-Chain T-Cell Antigen Receptor
- Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor
- Genes, T-Cell Receptor
- Humans
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Receptors, Antigen, T-Cell, gamma-delta/genetics
- Receptors, Antigen, T-Cell, gamma-delta/immunology
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
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Affiliation(s)
- Sandra M Hayes
- Department of Microbiology and Immunology, SUNY Upstate Medical University, Syracuse, NY, USA
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187
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Aiello FB, Keller JR, Klarmann KD, Dranoff G, Mazzucchelli R, Durum SK. IL-7 induces myelopoiesis and erythropoiesis. THE JOURNAL OF IMMUNOLOGY 2007; 178:1553-63. [PMID: 17237404 DOI: 10.4049/jimmunol.178.3.1553] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IL-7 administration to mice was previously reported to increase the mobilization of progenitor cells from marrow to peripheral sites. We now report that IL-7 increases the number of mature myeloid and monocytic cells in spleen and peripheral blood. This effect required T cells, and we show that IL-7 treatment in vivo induced GM-CSF and IL-3 production by T cells with memory phenotype. However, additional myelopoietic cytokines were shown to be involved because mice deficient in both GM-CSF and IL-3 also responded to IL-7 with increased myelopoiesis. Candidate cytokines included IFN-gamma and Flt3 ligand, which were also produced in response to IL-7. Because IFN-gamma-deficient mice also increased myelopoiesis, it was suggested that IL-7 induced production of redundant myelopoietic cytokines. In support of this hypothesis, we found that the supernatant from IL-7-treated, purified T cells contained myelopoietic activity that required a combination of Abs against GM-CSF, IL-3, and anti-Flt3 ligand to achieve maximum neutralization. IL-7 administration increased the number of splenic erythroid cells in either normal, Rag1 or GM-CSF-IL-3-deficient mice, suggesting that IL-7 might directly act on erythroid progenitors. In support of this theory, we detected a percentage of TER-119(+) erythroid cells that expressed the IL-7Ralpha-chain and common gamma-chain. Bone marrow cells expressing IL-7R and B220 generated erythroid colonies in vitro in response to IL-7, erythropoietin, and stem cell factor. This study demonstrates that IL-7 can promote nonlymphoid hemopoiesis and production of cytokines active in the host defense system in vivo, supporting its possible clinical utility.
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Affiliation(s)
- Francesca B Aiello
- Laboratory of Molecular Immunoregulation, National Cancer Institute, Frederick, MD 21702, USA
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188
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Regunathan J, Chen Y, Kutlesa S, Dai X, Bai L, Wen R, Wang D, Malarkannan S. Differential and nonredundant roles of phospholipase Cgamma2 and phospholipase Cgamma1 in the terminal maturation of NK cells. THE JOURNAL OF IMMUNOLOGY 2007; 177:5365-76. [PMID: 17015722 DOI: 10.4049/jimmunol.177.8.5365] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
NK cells play a central role in mediating innate immune responses. Activation of NK cells results in cytotoxicity, cytokine, and chemokine secretions. In this study, we show that in mice with targeted deletion of phospholipase Cgamma (PLCgamma)2, one of the key signal transducers, there are profound effects on the development and terminal maturation of NK cells. Lack of PLCgamma2 significantly impaired the ability of lineage-committed NK precursor cells to acquire subset-specific Ly49 receptors and thereby terminal maturation of NK cells. Overexpression of isozyme, PLCgamma1, in PLCgamma2-deficient NK cells resulted in the successful Ly49 acquisition and terminal maturation of the NK cells; however, it could only partially rescue NKG2D-mediated cytotoxicity with no cytokine production. Furthermore, PLCgamma2-deficient NK cells failed to mediate antitumor cytotoxicity and inflammatory cytokine production, displaying a generalized hyporesponsiveness. Our results strongly demonstrate that PLCgamma1 and PLCgamma2 play nonredundant and obligatory roles in NK cell ontogeny and in its effector functions.
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189
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Minegishi Y, Saito M, Morio T, Watanabe K, Agematsu K, Tsuchiya S, Takada H, Hara T, Kawamura N, Ariga T, Kaneko H, Kondo N, Tsuge I, Yachie A, Sakiyama Y, Iwata T, Bessho F, Ohishi T, Joh K, Imai K, Kogawa K, Shinohara M, Fujieda M, Wakiguchi H, Pasic S, Abinun M, Ochs HD, Renner ED, Jansson A, Belohradsky BH, Metin A, Shimizu N, Mizutani S, Miyawaki T, Nonoyama S, Karasuyama H. Human tyrosine kinase 2 deficiency reveals its requisite roles in multiple cytokine signals involved in innate and acquired immunity. Immunity 2006; 25:745-55. [PMID: 17088085 DOI: 10.1016/j.immuni.2006.09.009] [Citation(s) in RCA: 481] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Revised: 06/27/2006] [Accepted: 09/19/2006] [Indexed: 12/15/2022]
Abstract
Tyrosine kinase 2 (Tyk2) is a nonreceptor tyrosine kinase that belongs to the Janus kinase (Jak) family. Here we identified a homozygous Tyk2 mutation in a patient who had been clinically diagnosed with hyper-IgE syndrome. This patient showed unusual susceptibility to various microorganisms including virus, fungi, and mycobacteria and suffered from atopic dermatitis with elevated serum IgE. The patient's cells displayed defects in multiple cytokine signaling pathways including those for type I interferon (IFN), interleukin (IL)-6, IL-10, IL-12, and IL-23. The cytokine signals were successfully restored by transducing the intact Tyk2 gene. Thus, the Tyk2 deficiency is likely to account for the patient's complex clinical manifestations, including the phenotype of impaired T helper 1 (Th1) differentiation and accelerated Th2 differentiation. This study identifies human Tyk2 deficiency and demonstrates that Tyk2 plays obligatory roles in multiple cytokine signals involved in innate and acquired immunity of humans, which differs substantially from Tyk2 function in mice.
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Affiliation(s)
- Yoshiyuki Minegishi
- Department of Immune Regulation, Graduate School, Tokyo Medical and Dental University, Yushima, Tokyo, Japan.
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190
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Yang SM, Malaviya R, Wilson LJ, Argentieri R, Chen X, Yang C, Wang B, Cavender D, Murray WV. Simplified staurosporine analogs as potent JAK3 inhibitors. Bioorg Med Chem Lett 2006; 17:326-31. [PMID: 17088059 DOI: 10.1016/j.bmcl.2006.10.062] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2006] [Revised: 10/13/2006] [Accepted: 10/23/2006] [Indexed: 11/28/2022]
Abstract
Simplification of bottom ring and regioselective functionalization of the indolocarbazole unit of staurosporine (2) are described. The modification led to a new series of simplified staurosporine analogs, which exhibited significant inhibitory activity against Janus kinase 3 (JAK3). The structure-activity relationships (SAR) are discussed and a proposed binding model is also highlighted.
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Affiliation(s)
- Shyh-Ming Yang
- Johnson & Johnson Pharmaceutical Research and Development, L.L.C., 8 Clarke Drive, Cranbury, NJ 08512, USA.
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191
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Liu BA, Jablonowski K, Raina M, Arcé M, Pawson T, Nash PD. The human and mouse complement of SH2 domain proteins-establishing the boundaries of phosphotyrosine signaling. Mol Cell 2006; 22:851-868. [PMID: 16793553 DOI: 10.1016/j.molcel.2006.06.001] [Citation(s) in RCA: 232] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 05/19/2006] [Accepted: 06/02/2006] [Indexed: 01/07/2023]
Abstract
SH2 domains are interaction modules uniquely dedicated to the recognition of phosphotyrosine sites and are embedded in proteins that couple protein-tyrosine kinases to intracellular signaling pathways. Here, we report a comprehensive bioinformatics, structural, and functional view of the human and mouse complement of SH2 domain proteins. This information delimits the set of SH2-containing effectors available for PTK signaling and will facilitate the systems-level analysis of pTyr-dependent protein-protein interactions and PTK-mediated signal transduction. The domain-based architecture of SH2-containing proteins is of more general relevance for understanding the large family of protein interaction domains and the modular organization of the majority of human proteins.
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Affiliation(s)
- Bernard A Liu
- Ben May Institute for Cancer Research and the Committee on Cancer Biology, The University of Chicago, Chicago, Illinois 60637
| | - Karl Jablonowski
- Ben May Institute for Cancer Research and the Committee on Cancer Biology, The University of Chicago, Chicago, Illinois 60637
| | - Monica Raina
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto M5G 1X5, Canada
| | - Michael Arcé
- Ben May Institute for Cancer Research and the Committee on Cancer Biology, The University of Chicago, Chicago, Illinois 60637
| | - Tony Pawson
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto M5G 1X5, Canada.
| | - Piers D Nash
- Ben May Institute for Cancer Research and the Committee on Cancer Biology, The University of Chicago, Chicago, Illinois 60637.
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192
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Abstract
The production of blood cells is regulated by a number of protein growth factors and cytokines that influence cell survival, proliferation and differentiation. Many of these molecules bind to cell surface receptors, which belong to a family of closely related cytokine receptors that lack intrinsic catalytic activity but are intimately associated with tyrosine kinases of the Janus kinase (JAK) family. Ligand binding induces the activation of JAKs, which sit at the apex of a signalling cascade in which a key role is played by members of the signal transducers and activators of transcription (STAT) group. Congenital deficiencies in JAK-STAT signalling are associated with immunodeficiency states and acquired activating mutations and translocations are involved in the pathophysiology of haematological malignancy. The latter findings have raised hopes that drugs that target aberrant JAK-STAT signalling may be useful for the treatment of human disease.
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Affiliation(s)
- Asim Khwaja
- Department of Haematology, Royal Free and University College Medical School, London, UK.
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193
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Walters DK, Mercher T, Gu TL, O'Hare T, Tyner JW, Loriaux M, Goss VL, Lee KA, Eide CA, Wong MJ, Stoffregen EP, McGreevey L, Nardone J, Moore SA, Crispino J, Boggon TJ, Heinrich MC, Deininger MW, Polakiewicz RD, Gilliland DG, Druker BJ. Activating alleles of JAK3 in acute megakaryoblastic leukemia. Cancer Cell 2006; 10:65-75. [PMID: 16843266 DOI: 10.1016/j.ccr.2006.06.002] [Citation(s) in RCA: 242] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 04/21/2006] [Accepted: 06/01/2006] [Indexed: 12/18/2022]
Abstract
Tyrosine kinases are aberrantly activated in numerous malignancies, including acute myeloid leukemia (AML). To identify tyrosine kinases activated in AML, we developed a screening strategy that rapidly identifies tyrosine-phosphorylated proteins using mass spectrometry. This allowed the identification of an activating mutation (A572V) in the JAK3 pseudokinase domain in the acute megakaryoblastic leukemia (AMKL) cell line CMK. Subsequent analysis identified two additional JAK3 alleles, V722I and P132T, in AMKL patients. JAK3(A572V), JAK3(V722I), and JAK3(P132T) each transform Ba/F3 cells to factor-independent growth, and JAK3(A572V) confers features of megakaryoblastic leukemia in a murine model. These findings illustrate the biological importance of gain-of-function JAK3 mutations in leukemogenesis and demonstrate the utility of proteomic approaches to identifying clinically relevant mutations.
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MESH Headings
- Alleles
- Animals
- Apoptosis/drug effects
- Benzamides
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Cell Survival/drug effects
- Humans
- Imatinib Mesylate
- Janus Kinase 2
- Janus Kinase 3
- K562 Cells
- Leukemia, Experimental/genetics
- Leukemia, Experimental/metabolism
- Leukemia, Experimental/pathology
- Leukemia, Megakaryoblastic, Acute/genetics
- Leukemia, Megakaryoblastic, Acute/metabolism
- Leukemia, Megakaryoblastic, Acute/pathology
- Mice
- Mice, Inbred C57BL
- Models, Molecular
- Mutant Proteins/chemistry
- Mutant Proteins/genetics
- Mutant Proteins/metabolism
- Phosphorylation/drug effects
- Piperazines/pharmacology
- Protein Kinase Inhibitors/pharmacology
- Protein Structure, Tertiary/genetics
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Protein-Tyrosine Kinases/genetics
- Protein-Tyrosine Kinases/metabolism
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Pyrimidines/pharmacology
- RNA, Small Interfering/genetics
- TYK2 Kinase
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194
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Haan C, Kreis S, Margue C, Behrmann I. Jaks and cytokine receptors--an intimate relationship. Biochem Pharmacol 2006; 72:1538-46. [PMID: 16750817 DOI: 10.1016/j.bcp.2006.04.013] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Revised: 04/11/2006] [Accepted: 04/12/2006] [Indexed: 11/24/2022]
Abstract
Most cytokine receptors lack intrinsic kinase activity and many of them signal via Janus kinases (Jaks). These tyrosine kinases are associated with cytokine receptor subunits, they become activated upon receptor triggering and subsequently activate downstream signalling events, e.g. the phosphorylation of STAT transcription factors. The successful interplay between cytokines, their receptors and the connected Jaks not only determines signalling competence but is also vital for intracellular traffic, stability, and fate of the cognate receptors. Here, we will discuss underlying mechanisms as well as some structural features with a focus on Jak1 and two of the signal transducing receptor subunits of interleukin (IL)-6 type cytokines, gp130 and OSMR. Regions that are critically involved in Jak-binding have been identified for many cytokine receptor subunits. In most cases the membrane-proximal parts comprising the box1 and box2 regions within the receptor are involved in this association while, within Jaks, the N-terminal FERM domain, possibly together with the SH2-like domain, are pivotal for binding to the relevant receptors. The exclusive membrane localisation of Jaks depends on their ability to associate with cytokine receptors. For gp130 and Jak1, it was shown that the cytokine receptor/Jak complex can be regarded as a receptor tyrosine kinase since both molecules have the same diffusion dynamics and are virtually undissociable. Furthermore, Jaks take an active role in the regulation of the surface expression of at least some cytokine receptors, including the OSMR and this may provide a quality control mechanism ensuring that only signalling-competent receptors (i.e. those with an associated Jak) would be enriched at the cell surface.
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Affiliation(s)
- Claude Haan
- Laboratoire de Biologie et Physiologie Intégrée (LBPI), University of Luxembourg, 162a avenue de la Faïencerie, L-1511 Luxembourg, Luxembourg
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195
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Dai X, Chen Y, Schuman J, Hua Z, Adamson JW, Wen R, Wang D. Distinct roles of phosphoinositide-3 kinase and phospholipase Cgamma2 in B-cell receptor-mediated signal transduction. Mol Cell Biol 2006; 26:88-99. [PMID: 16354682 PMCID: PMC1317611 DOI: 10.1128/mcb.26.1.88-99.2006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
During B-cell receptor (BCR) signaling, phosphoinositide-3 kinase (PI3K) is thought to function upstream of phospholipase Cgamma2 (PLCgamma2). PLCgamma2 deficiency specifically impedes transitional type 2 (T2) to follicular (FO) mature B-cell transition. Here, we demonstrate that PI3K deficiency specifically impaired T2-to-FO mature B-cell transition and marginal zone B-cell development. Furthermore, we investigated the functional relationship between PI3K and PLCgamma2 using PI3K-/-, PLCgamma2-/-, and PI3K-/- PLCgamma2-/- B cells. Interestingly, PLCgamma2 deficiency had no effect on BCR-mediated PI3K activation, whereas PI3K deficiency only partially blocked activation of PLCgamma2. Moreover, whereas PI3K-/- PLCgamma2-/- double deficiency did not affect hematopoiesis, it resulted in embryonic lethality. PI3K-/- PLCgamma2-/- fetal liver cells transplanted into B-cell null JAK3-/- mice failed to restore development of peripheral B cells and failed to progress through early B-cell development at the pro-B- to pre-B-cell transition, a more severe phenotype than was observed with either PI3K or PLCgamma2 single-deficiency B cells. Consistent with this finding, BCR signaling was more severely impaired in the absence of both PI3K and PLCgamma2 genes than in the absence of either one alone. Taken together, these results demonstrate that whereas PI3K functions upstream of PLCgamma2, activation of PLCgamma2 can occur independently of PI3K and that PI3K and PLCgamma2 also have distinct functions in BCR signal transduction.
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Affiliation(s)
- Xuezhi Dai
- Blood Research Institute, 8727 Watertown Plank Rd., Milwaukee, WI 53226, USA
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196
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Nagasawa T. Microenvironmental niches in the bone marrow required for B-cell development. Nat Rev Immunol 2006; 6:107-16. [PMID: 16491135 DOI: 10.1038/nri1780] [Citation(s) in RCA: 307] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
B-cell development is known to occur in a complex bone-marrow microenvironment but its functional organization remains unclear. It is thought that bone-marrow stromal cells create distinct microenvironments, known as niches, that provide support for haematopoiesis and B-cell development. Although it has been more than 20 years since the development of a culture system that allows the growth of B-cell progenitors on bone-marrow-derived stromal cells in vitro, it is only recently that studies have provided a novel basis for understanding the nature of the niches for B-cell development in vivo. This article summarizes the recent advances in research on the earliest B-cell precursors, their requisite environmental factors and the cellular niches that supply these factors and maintain B cells during their development.
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Affiliation(s)
- Takashi Nagasawa
- Department of Medical Systems Control, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
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197
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Mangan JK, Tantravahi RV, Rane SG, Reddy EP. Granulocyte colony-stimulating factor-induced upregulation of Jak3 transcription during granulocytic differentiation is mediated by the cooperative action of Sp1 and Stat3. Oncogene 2006; 25:2489-99. [PMID: 16518416 DOI: 10.1038/sj.onc.1209280] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We previously demonstrated that Jak3 is a primary response gene for G-CSF and ectopic overexpression of Jak3 can accelerate granulocytic differentiation of normal mouse bone marrow cells induced by G-CSF and GM-CSF. To gain insight into the regulation of G-CSF-induced transcription of Jak3, we constructed deletion and linker scanning mutants of the Jak3 promoter sequences and performed luciferase reporter assays in the murine myeloid cell line 32Dcl3, with and without G-CSF stimulation. These experiments showed that mutation of a -67 to -85 element, which contained a putative Sp1 binding site, or mutation of a -44 to -53 GAS element resulted in a marked reduction of Jak3 promoter activity. Electrophoretic mobility shift assays revealed that Sp1 and Stat3 present in nuclear lysates of 32Dcl3 cells stimulated with G-CSF can bind to the -67 to -85 element and -44 to -53 GAS element, respectively. In addition, cotransfection of a constitutively active mutant of Stat3 along with a Jak3 promoter/luciferase reporter resulted in enhanced Jak3 promoter activity. Together, these results demonstrate that activation of Jak3 transcription during G-CSF- induced granulocytic differentiation is mediated by the combined action of Sp1 and Stat3, a mechanism also shown to be important in IL-6-induced monocytic differentiation.
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Affiliation(s)
- J K Mangan
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA, USA
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198
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Ono R, Ihara M, Nakajima H, Ozaki K, Kataoka-Fujiwara Y, Taki T, Nagata KI, Inagaki M, Yoshida N, Kitamura T, Hayashi Y, Kinoshita M, Nosaka T. Disruption of Sept6, a fusion partner gene of MLL, does not affect ontogeny, leukemogenesis induced by MLL-SEPT6, or phenotype induced by the loss of Sept4. Mol Cell Biol 2006; 25:10965-78. [PMID: 16314519 PMCID: PMC1316963 DOI: 10.1128/mcb.25.24.10965-10978.2005] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Septins are evolutionarily conserved GTP-binding proteins that can heteropolymerize into filaments. Recent studies have revealed that septins are involved in not only diverse normal cellular processes but also the pathogenesis of various diseases, including cancer. SEPT6 is ubiquitously expressed in tissues and one of the fusion partner genes of MLL in the 11q23 translocations implicated in acute leukemia. However, the roles of this septin in vivo remain elusive. We have developed Sept6-deficient mice that exhibited neither gross abnormalities, changes in cytokinesis, nor spontaneous malignancy. Sept6 deficiency did not cause any quantitative changes in any of the septins evaluated in this study, nor did it cause any additional changes in the Sept4-deficient mice. Even the depletion of Sept11, a close homolog of Sept6, did not affect the Sept6-null cells in vitro, thus implying a high degree of redundancy in the septin system. Furthermore, a loss of Sept6 did not alter the phenotype of myeloproliferative disease induced by MLL-SEPT6, thus suggesting that Sept6 does not function as a tumor suppressor. To our knowledge, this is the first report demonstrating that a disruption of the translocation partner gene of MLL in 11q23 translocation does not contribute to leukemogenesis by the MLL fusion gene.
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Affiliation(s)
- Ryoichi Ono
- Division of Hematopoietic Factors, The Institute of Medical Science, The University of Tokyo, Minato-ku, Japan
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199
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Yao Z, Cui Y, Watford WT, Bream JH, Yamaoka K, Hissong BD, Li D, Durum SK, Jiang Q, Bhandoola A, Hennighausen L, O'Shea JJ. Stat5a/b are essential for normal lymphoid development and differentiation. Proc Natl Acad Sci U S A 2006; 103:1000-5. [PMID: 16418296 PMCID: PMC1327727 DOI: 10.1073/pnas.0507350103] [Citation(s) in RCA: 295] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cytokines that use the common gamma chain gammac are critical for lymphoid development and function. Mutations of the IL-7 receptor, gammac, or its associated kinase, Jak3, are the major cause of human severe combined immunodeficiency. Although activated by IL-7, Stat5a/b (Stat, signal transducer and activator of transcription) have been thought to play limited roles in lymphoid development. However, we now show that mice completely deficient in Stat5a/b have severely impaired lymphoid development and differentiation. Absence of Stat5 also abrogates T cell receptor gamma rearrangement and survival of peripheral CD8(+) T cells. Thus, deficiency of Stat5 results in severe combined immunodeficiency, similar in many respects to deficiency of IL-7R, gammac, and Jak3.
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Affiliation(s)
- Zhengju Yao
- Molecular Immunology and Inflammation Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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200
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Abstract
Metazoan cells secrete small proteins termed cytokines that execute a variety of biological functions essential for the survival of organisms. Binding of cytokines that belong to the hematopoietin- or interferon-family, to their cognate receptors on the surface of target cells, induces receptor aggregation, which in turn sequentially triggers tyrosine-phosphorylation-dependent activation of receptor-associated Janus-family tyrosine kinases (JAKs), receptors, and signal transducers and activators of transcription (STATs). Phosphorylated STATs form dimers that migrate to the nucleus, bind to cognate enhancer elements and activate transcription of target genes. Each cytokine activates a specific set of genes to execute its biological functions with a certain degree of redundancy. Cytokine signals are, in general, transient in nature. Therefore, under normal physiological conditions, initiation and attenuation of cytokine signals are tightly controlled via multiple cellular and molecular mechanisms. Aberrant activation of cytokine signaling pathways is, however, found under a variety of patho-physiological conditions including cancer and immune diseases.
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Affiliation(s)
- S Jaharul Haque
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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