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)

Transformation of hematopoietic cells by the p210bcr/abl tyrosine kinase appears to require the expression of a functional MYC protein, suggesting that simultaneous targeting of BCR-ABL and c-myc might be a rational strategy for attempting treatment of Phil-adelphia leukemia. To test this hypothesis, severe combined immunodeficiency mice injected with Philadelphia leukemic cells were treated systemically with equal doses of bcr-abl or c-myc antisense oligodeoxynucleotides (ODNs) or with both ODNs in combination. Compared with the mice treated with individual agents, the disease process was much slower in the group treated with both ODNs, as revealed by flow cytometry, clonogenic assay, and reverse transcriptase-polymerase chain reaction analysis to detect leukemic cells in mouse tissue cell suspensions, and by enumeration of liver metastases. The retardation of the disease process was positively correlated with a markedly increased survival of leukemic mice treated with both ODNs. These data demonstrate the therapeutic potential of targeting multiple cooperating oncogenes.
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PMID:Leukemia treatment in severe combined immunodeficiency mice by antisense oligodeoxynucleotides targeting cooperating oncogenes. 750 9

Mutations affecting the expression of the Janus family kinase JAK3 were recently shown to be responsible for autosomal recessive severe combined immunodeficiency (SCID). JAK3-deficient patients present with a clinical phenotype virtually indistinguishable from boys affected by X-linked SCID, a disease caused by genetic defects of the common gamma chain (gamma c) that is a shared component of the receptors for IL-2, IL-4, IL-7, IL-9, and IL-15. The specific interaction of JAK3 and gamma c represents the biochemical basis for the similarities between these two immunodeficiencies. Both forms of SCID are characterized by recurrent, severe infections leading to death in infancy unless successfully treated by allogeneic bone marrow transplantation. Because of the potentially lethal complications associated with allogeneic bone marrow transplantation and the frequent lack of suitable marrow donors, the development of alternative forms of therapy is highly desirable. To this end, we investigated a retroviral-mediated gene correction approach for JAK3-deficiency. A vector carrying a copy of JAK3 cDNA was constructed and used to transduce B cell lines derived from patients with JAK3-deficient SCID. We demonstrate restoration of JAK3 expression and phosphorylation upon IL-2 and IL-4 stimulation. Furthermore, patients' cells transduced with JAK3 acquired the ability to proliferate normally in response to IL-2. These data indicate that the biological defects of JAK3-deficient cells can be efficiently corrected in vitro by retroviral-mediated gene transfer, thus providing the basis for future investigation of gene therapy as treatment for JAK3-deficient SCID.
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PMID:In vitro correction of JAK3-deficient severe combined immunodeficiency by retroviral-mediated gene transduction. 867 91

The recognition that defects of ZAP-70 and, more recently, of JAK3 kinase in humans result in severe combined immunodeficiency, and the demonstration that targeting of these and other protein-kinase genes in mice also leads to immunodeficiency, have highlighted the crucial role that these proteins play in T-cell differentiation and activation.
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PMID:Immunodeficiencies caused by genetic defects in protein kinases. 879 5

Cytokines that bind to the interleukin-2 (IL-2) receptor common gamma chain (gamma c), including IL-2, IL-4, IL-7, IL-9, and IL-15, are important for the growth and differentiation of T and B lymphocytes, natural killer cells, macrophages, and monocytes. These cytokines have overlapping biological effects that in part result from the use of the shared receptor subunit gamma c. Recently it has become clear that these cytokines activate a number of important intracellular signaling molecules, including the Janus kinases JAK1 and JAK3 and members of the transcription factor family of signal transducers and activators of transcription (STATs). The discovery of these signaling pathways has led to important new insights into their role in lymphocyte maturation, as it has emerged that mutations in the genes encoding both gamma c and JAK3 result in similar forms of severe combined immunodeficiency (SCID). In this review we examine the structure and function of cytokine receptors and the signaling pathways involved in their regulation of gene expression. Furthermore, we discuss recent advances that have led to a better understanding of how cytokines elicit intracellular responses, as well as their role in normal lymphoid development.
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PMID:Signaling by IL-2 and related cytokines: JAKs, STATs, and relationship to immunodeficiency. 886 27

Members of the Janus (JAK) protein tyrosine kinase family including JAK3 have recently emerged as important components in cytokine signal transduction. Mutations of JAK3 have been found in a number of patients who present with severe combined immunodeficiency. To facilitate the further identification of JAK3-SCID patients and to understand the structure of JAK3 better, we undertook the determination of the genomic sequence, organization, and chromosomal localization of the JAK3 gene. The JAK3 gene was found to consist of 19 exons and 18 introns. Interestingly, the organization of the kinase-(JH1) and pseudokinase-(JH2) domains were found to be dissimilar. In addition, the JAK3 gene was localized to human chromosome 19p13.1. These data should facilitate the identification of patients with this new form of immunodeficiency and will provide insight into the structure of this kinase.
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PMID:Genomic sequence, organization, and chromosomal localization of human JAK3. 892 70

JAK3 is a protein tyrosine kinase that specifically associates with the common gamma chain (gammac), a shared subunit of receptors for interleukin (IL) 2, 4, 7, 9, and 15. Patients deficient in either JAK3 or gammac presented with virtually identical forms of severe combined immunodeficiency (SCID), underscoring the importance of the JAK3-gammac interaction. Despite the key roles of JAK3 and gammac in lymphocytic development and function, the molecular basis of this interaction remains poorly understood. In this study, we have characterized the regions of JAK3 involved in gammac association. By developing a number of chimeric JAK3-JAK2 constructs, we show that the binding specificity to gammac can be conferred to JAK2 by transferring the N-terminal domains of JAK3. Moreover, those JAK3-JAK2 chimeras capable of binding gammac were also capable of reconstituting IL-2 signaling as measured by inducible phosphorylation of the chimeric JAK3-JAK2 protein, JAK1, the IL-2 receptor beta chain, and signal transducer and activator of transcription 5A. Subsequent deletion analyses of JAK3 have identified the N-terminal JH7-6 domains as a minimal region sufficient for gammac association. Furthermore, expression of the mutant containing only the JH7-6 domains effectively competed with full-length JAK3 for binding to gammac. We conclude that the JH7-6 domains of JAK3 are necessary and sufficient for gammac association. These studies offer clues toward a broader understanding of JAK-mediated cytokine signaling and may provide a target for the development of novel therapeutic modalities in immunologically mediated diseases.
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PMID:The amino terminus of JAK3 is necessary and sufficient for binding to the common gamma chain and confers the ability to transmit interleukin 2-mediated signals. 919 65

Ex vivo culture of human hematopoietic cells is a crucial component of many therapeutic applications. Although current culture conditions have been optimized using quantitative in vitro progenitor assays, knowledge of the conditions that permit maintenance of primitive human repopulating cells is lacking. We report that primitive human cells capable of repopulating nonobese diabetic (NOD)/severe combined immunodeficiency (SCID) mice (SCID-repopulating cells; SRC) can be maintained and/or modestly increased after culture of CD34+CD38- cord blood cells in serum-free conditions. Quantitative analysis demonstrated a 4- and 10-fold increase in the number of CD34+CD38- cells and colony-forming cells, respectively, as well as a 2- to 4-fold increase in SRC after 4 d of culture. However, after 9 d of culture, all SRC were lost, despite further increases in total cells, CFC content, and CD34+ cells. These studies indicate that caution must be exercised in extending the duration of ex vivo cultures used for transplantation, and demonstrate the importance of the SRC assay in the development of culture conditions that support primitive cells.
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PMID:Quantitative analysis reveals expansion of human hematopoietic repopulating cells after short-term ex vivo culture. 925 60

Mutations of the Janus family kinase JAK3 have been found to be responsible for autosomal recessive severe combined immunodeficiency (SCID) in humans. We report here the analysis of four new unrelated patients affected by JAK3-deficient SCID. The genetic defects were heterogeneous and included a large intragenic deletion as well as different point mutations, leading to missense substitutions, early stop codons, or splicing defects. We performed a series of studies of the biochemical events induced by cytokines on lymphoblastoid B-cell lines obtained from these patients. Abnormalities in tyrosine phosphorylation of JAK3 in response to interleukin-2 (IL-2) and IL-4 were present in all patients. Accordingly, IL-2-mediated phosphorylation of STAT5 was also absent or barely detectable. On the contrary, in all cases, we could show reduced but clear phosphorylation of STAT6 upon IL-4 stimulation. In one patient carrying a single amino acid change (Glu481Gly) in the JH3 domain of JAK3, we observed partially conserved IL-2 responses resulting in reduced but detectable levels of JAK3 and STAT5 phosphorylation. Interestingly, the patient bearing this mutation developed a substantial number of circulating CD4(+)/CD45RO+ activated T lymphocytes that were functionally impaired. In two cases, patients' cells expressed JAK3 proteins with mutations in the JH2 pseudo-kinase domain. A single cysteine to arginine substitution (Cys759Arg) in this region resulted in high basal levels of constitutive JAK3 tyrosine phosphorylation unresponsive to either downregulation by serum starvation or cytokine-mediated upregulation. The characterization of the genetic defects and biochemical abnormalities in these JAK3-deficient patients will help define the role of JAK3 in the ontogeny of a competent immune system and may lead to a better understanding of the JAK3 functional domains.
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PMID:Structural and functional basis for JAK3-deficient severe combined immunodeficiency. 935 68

Human severe combined immunodeficiency (SCID) can be caused by defects in Janus kinase 3 (JAK3)-dependent cytokine signaling pathways. As a result, patients are at high risk of life-threatening infection. A JAK3 -/- SCID mouse model for the human disease has been used to test whether transplant with retrovirally transduced bone marrow (BM) cells (JAK3 BMT) could restore immunity to an influenza A virus. The immune responses also were compared directly with those for mice transplanted with wild-type BM (+/+ BMT). After infection, approximately 90% of the JAK3 BMT or +/+ BMT mice survived, whereas all of the JAK3 -/- mice died within 29 days. Normal levels of influenza-specific IgG were present in plasma from JAK3 BMT mice at 14 days after respiratory challenge, indicating restoration of B cell function. Influenza-specific CD4(+) and CD8(+) T cells were detected in the spleen and lymph nodes, and virus-specific CD8(+) effectors localized to the lungs of the JAK3 BMT mice. The kinetics of the specific host response correlated with complete clearance of the virus within 2 weeks of the initial exposure. By contrast, the JAK3 -/- mice did not show any evidence of viral immunity and were unable to control this viral pneumonia. Retroviral-mediated JAK3 gene transfer thus restores diverse aspects of cellular and humoral immunity and has obvious potential for human autologous BMT.
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PMID:Virus-specific immunity after gene therapy in a murine model of severe combined immunodeficiency. 987 1

Signal transducer and activator of transcription (STAT)5 is constitutively activated in BCR/ ABL-expressing cells, but the mechanisms and functional consequences of such activation are unknown. We show here that BCR/ABL induces phosphorylation and activation of STAT5 by a mechanism that requires the BCR/ABL Src homology (SH)2 domain and the proline-rich binding site of the SH3 domain. Upon expression in 32Dcl3 growth factor-dependent myeloid precursor cells, STAT5 activation-deficient BCR/ABL SH3+SH2 domain mutants functioned as tyrosine kinase and activated Ras, but failed to protect from apoptosis induced by withdrawal of interleukin 3 and/or serum and did not induce leukemia in severe combined immunodeficiency mice. In complementation assays, expression of a dominant-active STAT5B mutant (STAT5B-DAM), but not wild-type STAT5B (STAT5B-WT), in 32Dcl3 cells transfected with STAT5 activation-deficient BCR/ABL SH3+SH2 mutants restored protection from apoptosis, stimulated growth factor-independent cell cycle progression, and rescued the leukemogenic potential in mice. Moreover, expression of a dominant-negative STAT5B mutant (STAT5B-DNM) in 32Dcl3 cells transfected with wild-type BCR/ABL inhibited apoptosis resistance, growth factor-independent proliferation, and the leukemogenic potential of these cells. In retrovirally infected mouse bone marrow cells, expression of STAT5B-DNM inhibited BCR/ABL-dependent transformation. Moreover, STAT5B-DAM, but not STAT5B-WT, markedly enhanced the ability of STAT5 activation-defective BCR/ABL SH3+SH2 mutants to induce growth factor-independent colony formation of primary mouse bone marrow progenitor cells. However, STAT5B-DAM did not rescue the growth factor-independent colony formation of kinase-deficient K1172R BCR/ABL or the triple mutant Y177F+R522L+ Y793F BCR/ABL, both of which also fail to activate STAT5. Together, these data demonstrate that STAT5 activation by BCR/ABL is dependent on signaling from more than one domain and document the important role of STAT5-regulated pathways in BCR/ABL leukemogenesis.
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PMID:Signal transducer and activator of transcription (STAT)5 activation by BCR/ABL is dependent on intact Src homology (SH)3 and SH2 domains of BCR/ABL and is required for leukemogenesis. 1020 40


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