RESUMO
BACKGROUND: Cytomegalovirus (CMV) disease constitutes a serious complication after allogeneic stem cell transplantation. For the clearance of CMV, CD8+ T cells are pivotal. STUDY DESIGN AND METHODS: Here, the novel streptamer technology was used at good manufacturing practice (GMP) level for adoptive transfer of CMV-specific T cells into acute leukemia patients with recurrent high CMV antigenemia after allogeneic stem cell transplantation. RESULTS: After a single transfusion, the frequency of CMV-specific CD8+CD45RA+CCR7- effector T cells increased dramatically from 0.0% to a maximum of 27.1% of all T cells. These T cells were clearly donor derived and did not stem from intrinsic reconstitution, as demonstrated by analysis of 1) donor chimerism through single-tandem repeats, 2) T-cell receptor excision circles, and 3) Vß-chain typing by polymerase chain reaction. Clinically, the specific T-cell transfer resulted in a persistent clearance of the CMV antigenemia, which allowed the patients to discontinue toxic antiviral drug therapy without further high-level reactivation of CMV, demonstrating the power of the streptamer technology. CONCLUSION: Taken together, the streptamer technology offers the advantage of selecting virus-specific CD8+ T cells at GMP level for adoptive T-cell transfer, thus inducing long-lasting specific CD8+ T-cell responses without increasing the risk for graft-versus-host disease.
Assuntos
Transferência Adotiva , Linfócitos T CD8-Positivos/imunologia , Citomegalovirus/imunologia , Transplante de Células-Tronco de Sangue Periférico , Adulto , Feminino , Humanos , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/terapia , Fosfoproteínas/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Transplante Homólogo , Proteínas da Matriz Viral/imunologiaRESUMO
The Bcr-Abl tyrosine kinase activates various signaling pathways including nuclear factor kappaB that mediate proliferation, transformation, and apoptosis resistance in Bcr-Abl(+) myeloid leukemia cells. Here we report that protein kinase (PK) D2, a serine threonine kinase of the PKD family, is a novel substrate of Bcr-Abl. PKD2 was found to be the major isoform of the PKD family expressed in chronic myeloid leukemia cells and is tyrosine phosphorylated by Bcr-Abl in its pleckstrin homology domain. A mutant that mimicks tyrosine phosphorylation of PKD2 in the pleckstrin homology domain activates nuclear factor kappaB independently of its catalytic activity. Furthermore, our data show that Bcr-Abl-induced activation of the nuclear factor kappaB cascade in LAMA84 cells is largely mediated by tyrosine-phosphorylated PKD2. These data present a novel mechanism of Bcr-Abl-induced nuclear factor kappaB activation in myeloid leukemia. Targeting PKD2 tyrosine phosphorylation, not its kinase activity, could be a novel therapeutic approach for the treatment of Bcr-Abl(+) myeloid leukemia.
Assuntos
Proteínas de Fusão bcr-abl/metabolismo , Leucemia Mieloide/metabolismo , NF-kappa B/metabolismo , Proteínas Quinases/metabolismo , Linhagem Celular Tumoral , Humanos , Isoenzimas , Leucemia Mieloide/enzimologia , Leucemia Mieloide/genética , Mutagênese Sítio-Dirigida , Estresse Oxidativo , Fosforilação , Proteína Quinase D2 , Proteínas Quinases/genética , Estrutura Terciária de Proteína , TransfecçãoRESUMO
Transformation of normal cells into malignant tumor cells, a process termed carcinogenesis, depends on progressive acquisition of genetic alterations. These result in activation of protooncogenes or inactivation of tumor suppressor genes responsible for the loss of proliferative control in tumor cells and the failure to undergo cellular differentiation. The aim of our study was the identification of molecular regulators of carcinogenesis by studying gene expression during induction of cellular differentiation and quiescence in a three-dimensional (3D) cell culture model. Here, we report the discovery of a tumor suppressor gene located at chromosome 8p21.3-22 near marker D8S254. It is ubiquitously expressed in normal tissue and transiently up-regulated during initiation of cellular differentiation and quiescence in 3D cell culture. In contrast, mRNA expression was not detectable in tissue from pancreatic tumor and the pancreatic tumor cell line MIA PaCa-2. Recombinant expression in the tumor cell line MIA PaCa-2 inhibited proliferation, as shown by a 30% reduction of BrdU uptake after recombinant expression. Immunocytochemistry and Western blot analysis of subcellular fractions demonstrated a mitochondrial localization for the mature protein. In conclusion, we identified a tumor suppressor gene at chromosome 8p21.3-22, encoding a mitochondrial protein, controlling cellular proliferation.
Assuntos
Cromossomos Humanos Par 8 , Genes Supressores de Tumor , Proteínas Supressoras de Tumor/genética , Sequência de Bases , Diferenciação Celular , Divisão Celular , Células Cultivadas , Clonagem Molecular , Éxons , Humanos , Mitocôndrias/química , Modelos Biológicos , Dados de Sequência Molecular , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , RNA Mensageiro/biossíntese , Análise de Sequência de DNA , Distribuição Tecidual , Células Tumorais Cultivadas , Proteínas Supressoras de Tumor/análise , Proteínas Supressoras de Tumor/biossíntese , Regulação para CimaAssuntos
Falência Hepática/enfermagem , Educação de Pacientes como Assunto , Acetaminofen/administração & dosagem , Acetaminofen/efeitos adversos , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/efeitos adversos , Nefropatias Diabéticas/complicações , Nefropatias Diabéticas/enfermagem , Nefropatias Diabéticas/prevenção & controle , Relação Dose-Resposta a Droga , Humanos , Hipertensão/complicações , Hipertensão/enfermagem , Hipertensão/prevenção & controle , Falência Hepática/etiologia , Falência Hepática/prevenção & controleRESUMO
A pilot trial was initiated for chronic myeloid leukaemia patients, which employed imatinib for remission induction, followed by reduced-intensity conditioning and an in vivo T-cell depleted graft. Out of nine patients, six experienced a molecular relapse and one patient had a haematological relapse at a median interval of 5 months after transplantation. Five relapsing patients achieved a 2nd molecular remission after treatment with either donor lymphocyte infusions (n = 4) or imatinib (n = 1). Two of nine patients died due to infectious complications. The probability of survival 2 years after transplant was 74% (95% CI 42-100%).