Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.10.2 (focal adhesion kinase)
 44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

JAK3 is a cytoplasmic tyrosine kinase with limited tissue expression but is readily found in activated T cells. Patients lacking JAK3 are immune compromised, suggesting that JAK3 represents a therapeutic target for immunosuppression. Herein, we show that a Mannich base, NC1153, blocked IL-2-induced activation of JAK3 and its downstream substrates STAT5a/b more effectively than activation of the closely related prolactin-induced JAK2 or TNF-alpha-driven NF-kappaB. In addition, NC1153 failed to inhibit several other enzymes, including growth factor receptor tyrosine kinases, Src family members, and serine/threonine protein kinases. Although NC1153 inhibited proliferation of normal human T cells challenged with IL-2, IL-4, or IL-7, it did not block T cells void of JAK3. In vivo, a 14-day oral therapy with NC1153 significantly extended survival of MHC/non-MHC mismatched rat kidney allografts, whereas a 90-day therapy induced transplantation tolerance (>200 days). Although NC1153 acted synergistically with cyclosporin A (CsA) to prolong allograft survival, it was not nephrotoxic, myelotoxic, or lipotoxic and did not increase CsA-induced nephrotoxicity. In contrast to CsA, NC1153 was not metabolized by cytochrome P450 3A4. Thus, NC1153 prolongs allograft survival without several toxic effects associated with current immunosuppressive drugs.
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PMID:The Mannich base NC1153 promotes long-term allograft survival and spares the recipient from multiple toxicities. 1617 63

Matk/CHK knockout mice were reported to show no apparent phenotypic abnormalities. This was thought to be due to the homologous kinase Csk that compensates for Matk/CHK. Here, we present the first evidence that the nonreceptor tyrosine kinase, Matk/CHK, is an important modulator of immune cell signaling. We found that the frequency of primitive hematopoietic cells, the side population c-kit(+) Lin(-) Sca-1(+) (SPKLS) cells, in Matk/CHK(-/-) mice was increased 2.2-fold compared with the control mice. Moreover, Matk/CHK deficiency led to significantly higher pre-B cell colony formation following IL-7 stimulation. Interestingly, when mice received the in vivo antigen challenge of TNP-ovalbumin followed by restimulation, the Matk/CHK(-/-) lymph node and spleen cells produced significantly lower IFN-gamma levels compared with the respective wild-type cells. Our study indicates that Matk/CHK is not functionally redundant with Csk, and that this tyrosine kinase plays an important role as a regulator of immunologic responses.
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PMID:Identification of the nonreceptor tyrosine kinase MATK/CHK as an essential regulator of immune cells using Matk/CHK-deficient mice. 1657 55

Mouse bone marrow cells transduced with retroviral vectors encoding either of two oncogenic Bcr-Abl isoforms (p210(Bcr-Abl) and p185(Bcr-Abl)) induce B cell lympholeukemias when transplanted into lethally irradiated mice. If the activity of the Arf tumor suppressor is compromised, these donor cells initiate a much more highly aggressive and rapidly fatal disease. When mouse bone marrow cells expressing Bcr-Abl are placed in short-term cultures selectively designed to support the outgrowth of pre-B cells, only those lacking one or two Arf alleles can initiate lympholeukemias when inoculated into immunocompetent, syngeneic recipient mice. Although the ABL kinase inhibitor imatinib mesylate (Gleevec) provides highly effective treatment for BCR-ABL-positive chronic myelogenous leukemia, it has proven far less efficacious in the treatment of BCR-ABL-positive acute lymphoblastic leukemias (ALLs), many of which sustain deletions of the INK4A-ARF (CDKN2A) tumor suppressor locus. Mice receiving Arf-/- or Arf+/- p210(Bcr-Abl)-positive pre-B cells do not achieve remission when maintained on high doses of oral imatinib therapy and rapidly succumb to lympholeukemia. Although cells expressing the Bcr-Abl kinase can proliferate in the absence of IL-7, they remain responsive to this cytokine, which can reduce their sensitivity to imatinib. Treatment of Arf-/-, p210(Bcr-Abl)-positive pre-B cells with imatinib together with an inhibitor of JAK kinases abrogates this resistance, suggesting that this combination may prove beneficial in the treatment of BCR-ABL-positive acute lymphoblastic leukemia.
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PMID:Arf gene loss enhances oncogenicity and limits imatinib response in mouse models of Bcr-Abl-induced acute lymphoblastic leukemia. 1661 32

Thymic plasmacytoid dendritic cells (pDCs) are located predominantly in the medulla and at the corticomedullary junction, the entry site of bone marrow-derived multipotential precursor cells into the thymus, allowing for interactions between thymic pDCs and precursor cells. We demonstrate that in vitro-generated pDCs stimulated with CpG or virus impaired the development of human autologous CD34(+)CD1a(-) thymic progenitor cells into the T-cell lineage. Rescue by addition of neutralizing type I interferon (IFN) antibodies strongly implies that endogenously produced IFN-alpha/beta is responsible for this inhibitory effect. Consistent with this notion, we show that exogenously added IFN-alpha had a similar impact on IL-7- and Notch ligand-induced development of thymic CD34(+)CD1a(-) progenitor cells into T cells, because induction of CD1a, CD4, CD8, and TCR/CD3 surface expression and rearrangements of TCRbeta V-DJ gene segments were severely impaired. In addition, IL-7-induced proliferation but not survival of the developing thymic progenitor cells was strongly inhibited by IFN-alpha. It is evident from our data that IFN-alpha inhibits the IL-7R signal transduction pathway, although this could not be attributed to interference with either IL-7R proximal (STAT5, Akt/PKB, Erk1/2) or distal (p27(kip1), pRb) events.
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PMID:Stimulated plasmacytoid dendritic cells impair human T-cell development. 1691 11

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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PMID:IL-7 activates the phosphatidylinositol 3-kinase/AKT pathway in normal human thymocytes but not normal human B cell precursors. 1852 75

Purified protein derivative (PPD) or tuberculin skin testing is used to identify infected individuals with Mycobacterium tuberculosis (Mtb) and to assess cell-mediated immunity to Mtb. In the present study, we compared PBMC cultures in the presence of tuberculin or Candida antigens using cytokine bead arrays and RNA microarrays. Measurements of different cytokines and chemokines in supernatants of PMBC cultures in the presence of PPD showed increased levels of interferon (IFN)-gamma in active tuberculosis infection (ATBI) and latent TB infected (LTBI) compared to controls, and increased levels of TNF-alpha in ATBI compared with LTBI. Also, we found increase of IL-6 in cultures of PPD positive and controls but not in the cultures with Candida. We also report the molecular signature of tuberculosis infection, in ATBI patients, the following genes were found to be up-regulated and absent in LTBI individuals: two kinases (JAK3 and p38MAPK), four interleukins (IL-7, IL-2, IL-6, and IFNbeta1), a chemokine (HCC-4) a chemokine receptor (CxCR5), two interleukin receptors (IL-1R2 and IL-18R1), and three additional ones (TRAF5, Smad2, CIITA, and NOS2A). By contrast, IL-17 and IGFBP3 were significantly up-regulated in LTBI. And, STAT4, GATA3, Fra-1, and ICOS were down-regulated in ATBI but absent in LTBI. Conversely, TLR-10, IL-15, DORA, and IKK-beta were down-regulated in LTBI but not in ATBI. Interestingly, the majority of the up-regulated genes found in ATBI were found in cultures stimulated with tuberculin (PPD) or Candida antigens, suggesting that these pathogens stimulate similar immunological pathways. We believe that the molecular signature distinguishing active from latent tuberculosis infection may require using cytokine bead arrays along with RNA microarrays testing cell cultures at different times following in vitro proliferation assays using several bacterial antigens and PPD.
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PMID:Molecular signatures distinguishing active from latent tuberculosis in peripheral blood mononuclear cells, after in vitro antigenic stimulation with purified protein derivative of tuberculin (PPD) or Candida: a preliminary report. 1864 50

Pre-B-cell leukemia spontaneously develops in BLNK-deficient mice, and pre-B-cell acute lymphoblastic leukemia cells in children often lack BLNK protein expression, demonstrating that BLNK functions as a tumor suppressor. However, the mechanism by which BLNK suppresses pre-B-cell leukemia, as well as the identification of other genetic alterations that collaborate with BLNK deficiency to cause leukemogenesis, are still unknown. Here, we demonstrate that the JAK3/STAT5 signaling pathway is constitutively activated in pre-B leukemia cells derived from BLNK(-/-) mice, mostly due to autocrine production of IL-7. Inhibition of IL-7R signaling or JAK3/STAT5 activity resulted in the induction of p27(kip1) expression and cell-cycle arrest, accompanied by apoptosis in the leukemia cells. Transgene-derived constitutively active STAT5 (STAT5b-CA) strongly synergized with the loss of BLNK to initiate leukemia in vivo. In the leukemia cells, exogenously expressed BLNK inhibited autocrine JAK3/STAT5 signaling, resulting in p27(kip1) induction, cell-cycle arrest, and apoptosis. BLNK-inhibition of JAK3 was dependent on the binding of BLNK to JAK3. These data indicate that BLNK normally regulates IL-7-dependent proliferation and survival of pre-B cells through direct inhibition of JAK3. Thus, somatic loss of BLNK and concomitant mutations leading to constitutive activation of Jak/STAT5 pathway result in the generation of pre-B-cell leukemia.
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PMID:BLNK suppresses pre-B-cell leukemogenesis through inhibition of JAK3. 1904 79

IRX-2 is a cytokine-based biologic agent that has the potential to enhance antitumor immune responses. We investigated whether IRX-2 can protect T cells from tumor-induced apoptosis. Tumor-derived microvesicles (MV) expressing FasL were purified from supernatants of tumor cells and incubated with activated CD8(+) T cells. MV induced significant CD8(+) T-cell apoptosis, as evidenced by Annexin binding (64.4+/-6.4%), caspase activation (58.1+/-7.6%), a loss of mitochondrial membrane potential (82.9+/-3.9%) and DNA fragmentation. T-cell pretreatment with IRX-2 prevented apoptosis. IRX-2-mediated cytoprotection was dose and time dependent and was comparable to effects of IL-2, IL-7 or IL-15. IRX-2 prevented MV-induced downregulation of JAK3 and TCRzeta chain and induced STAT5 activation in T cells. IRX-2 prevented MV-induced Bax and Bim upregulation (P<0.005-0.05), prevented cytochrome c release and Bid cleavage, and concurrently restored the expression of Bcl-2, Bcl-xL, FLIP and Mcl-1 (P<0.005-0.01) in T cells. In addition, IRX-2 reversed MV-induced inhibition of the PI3K/Akt pathway. An Akt inhibitor (Akti-1/2) abrogated protective effects of IRX-2, suggesting that Akt is a downstream target of IRX-2 signaling. Thus, ex vivo pretreatment of CD8(+) T cells with IRX-2 provided potent protection from tumor-induced apoptosis. IRX-2 application to future cancer biotherapies could improve their effectiveness by bolstering T-cell resistance to tumor-induced immunosuppression.
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PMID:IRX-2, a novel immunotherapeutic, protects human T cells from tumor-induced cell death. 1918 Jan 18

JAK3, a member of the Janus kinase family, is predominantly expressed in hemopoietic cells and binds specifically to the common gamma chain of a subfamily of cytokine receptors that includes IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21. Previous studies suggest that this tyrosine kinase plays key roles in mediating T cell functions, and inhibition of JAK3 has been shown to prevent graft rejection and decrease the severity of arthritis in rodent models. However, the functions of JAK3 in the development of skin immune responses and diseases such as psoriasis have not been determined. CD18 mutant PL/J mice develop spontaneous T cell-dependent psoriasiform skin disease with several similarities to human psoriasis. In this study, we treated mice with established skin disease with R348, a small molecule inhibitor of JAK3, and observed a marked attenuation of skin lesions following 6 wk of treatment. Histological analyses revealed major reductions of both epidermal and dermal lesion severity scores in R348-treated CD18-deficient PL/J mice compared with vehicle controls, which was associated with decreased CD4(+) T cell infiltration. In addition, systemic levels of IL-17, IL-22, IL-23, and TNF-alpha were significantly lower in mice receiving the compound, and T cells isolated from R348-treated mice also showed reduced phosphorylation of Stat5 after stimulation with IL-2. These findings suggest that small-molecule inhibitors of JAK3 may be useful in the treatment of inflammatory skin diseases such as psoriasis and strongly implicate JAK signaling events as important in the pathogenesis of this disease.
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PMID:JAK3 inhibition significantly attenuates psoriasiform skin inflammation in CD18 mutant PL/J mice. 1959 99

Janus kinase 3-severe combined immunodeficiency (JAK3-SCID) is an autosomal recessive immunodeficiency disease caused by various mutations in the JAK3 gene. Typical JAK3-SCID is characterized by a phenotype in which B cells are present but T and NK cells are not, the T(-)B(+)NK(-) phenotype, and by impaired signaling through cytokine receptors that use the common gamma chain (gammac) subunit. An atypical JAK3-SCID case carrying a single glutamate to glycine substitution mutation (E481G) in the JH3 domain of one JAK3 allele, and a deletion mutation (del482-596) in the JH3 and JH2 domains of the other allele was reported previously. Although this patient had CD4(+) T cells and NK cells unlike typical cases, the CD4(+) T cells were functionally impaired. We report here that the JAK3-E481G mutant transduced IL-2-, IL-4-, IL-15-, and IL-21-induced signals as efficiently as wild-type JAK3. However, this mutant failed to respond to IL-7 by phosphorylating JAK1, JAK3, or STAT5. The other mutant JAK3, JAK3-del482-596, was non-functional. Thus, an impaired IL-7 signal may cause SCID and compromise T-cell differentiation, even if the IL-15 signal is preserved and supports NK-cell development, as in this patient.
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PMID:Impaired IL-7 signaling may explain a case of atypical JAK3-SCID. 1988 52


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