Suchergebnisse

Activation-induced cytidine deaminase (AID) is essential for somatic hypermutation and class switch recombination in mature B-cells, while AID was also shown to play a role in developing pre-BCR/BCR-positive B-cells of the bone marrow. To further elucidate a potential function of Aid in the bone marrow prior to V(D) J-recombination, we utilized an in vivo model which exerts a B-cell developmental arrest at the pro-B cell stage with low frequencies of pro-B cell acute lymphoblastic leukemia (pro-B ALL) development. Therefore, p19ArfRag1 (AR) mice were crossed with Aid-deficient mice (ARA). Surprisingly, loss of Aid expression in pro-B cells accelerated pro-B ALL incidence from 30% (AR) to 98% (ARA). This effect was Aid dose dependent, since Aid animals of the same background displayed a significantly lower incidence (83%). Furthermore, B-cell-specific Aid up-regulation was observed in Aid-competent pro-B ALLs. Additional whole exome/sanger sequencing of murine pro-B ALLs revealed an accumulation of recurrent somatic Jak3 (p. R653H, p. V670A) and Dnm2 (p. G397R) mutations, which highlights the importance of active IL7R signaling in the pro-B ALL blast cells. These findings were further supported by an enhanced proliferative potential of ARA pro-B cells compared to Aid-competent cells from the same genetic background. In summary, we show that both Aid and Rag1 act as a negative regulators in pro-B cells, preventing pro-B ALL. ; J. Hauer has been supported by the German Cancer Foundation (110997), DJCLS02R/2016, KKS A2016/07 and from the "Forschungskommission" of the medical faculty of the Heinrich Heine University. A. Borkhardt has been supported by the German Children's Cancer Foundation and the Federal Ministry of Education and Research, Bonn, Germany. Research in I. Sánchez-García's group is partially supported by FEDER and by MINECO (SAF2012-32810, SAF2015-64420-R and Red de Excelencia Consolider OncoBIO SAF2014-57791-REDC), Instituto de Salud Carlos III (PIE14/00066), ISCIII- Plan de Ayudas IBSAL 2015 Proyectos Integrados (IBY15/00003), by Junta de Castilla y León (BIO/SA51/15, CSI001 U14, UIC-017, and CSI001U16), Fundacion Inocente Inocente and by the ARIMMORA project (European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 282891). I. Sánchez-García's lab is a member of the EuroSyStem and the DECIDE Network funded by the European Union under the FP7 program. A. Borkhardt and I. Sánchez-García have been supported by the German Carreras Foundation (DJCLS R13/26). Research in C. Vicente-Dueñas' group is partially supported by a "Miguel Servet" Grant (CP14/00082 - AES 2013-2016 - FEDER) from the Instituto de Salud Carlos III (Ministerio de Economía y Competitividad) and by the Lady Tata International Award for Research in Leukaemia 2016-2017. A. Martín-Lorenzo was supported by FSE-Conserjería de Educación de la Junta de Castilla y León (CSI001-13). ; Peer Reviewed

WOS: 000352238600023 ; PubMed ID: 25312759 ; Background: Immunoglobulin class-switch recombination defects (CSR-D) are rare primary immunodeficiencies characterized by impaired production of switched immunoglobulin isotypes and normal or elevated IgM levels. They are caused by impaired T:B cooperation or intrinsic B cell defects. However, many immunoglobulin CSR-Ds are still undefined at the molecular level. Objective: This study's objective was to delineate new causes of immunoglobulin CSR-Ds and thus gain further insights into the process of immunoglobulin class-switch recombination (CSR). Methods: Exome sequencing in 2 immunoglobulin CSR-D patients identified variations in the INO80 gene. Functional experiments were performed to assess the function of INO80 on immunoglobulin CSR. Results: We identified recessive, nonsynonymous coding variations in the INO80 gene in 2 patients affected by defective immunoglobulin CSR. Expression of wild-type INO80 in patients' fibroblastic cells corrected their hypersensitivity to high doses of gamma-irradiation. In murine CH12-F3 cells, the INO80 complex accumulates at Sa and Em regions of the IgH locus, and downregulation of INO80 as well as its partners Reptin and Pontin impaired CSR. In addition, Reptin and Pontin were shown to interact with activation-induced cytidine deaminase. Finally, an abnormal separation of sister chromatids was observed upon INO80 downregulation in CH12-F3 cells, pinpointing its role in cohesin activity. Conclusion: INO80 deficiency appears to be associated with defective immunoglobulin CSR. We propose that the INO80 complex modulates cohesin function that may be required during immunoglobulin switch region synapsis. ; National Institute of Health and Medical ResearchInstitut National de la Sante et de la Recherche Medicale (Inserm); le fonds de recherche clinique du Ministere de la Sante; European Union (EUROPAD) [201549]; European Union (ERC advanced grant PID-IMMUNE) [249816]; Association Contre Le Cancer; Fondation pour la Recherche MedicaleFondation pour la Recherche Medicale [ING20130526624]; la Ligue Contre le Cancer (Comite de Paris); Agence Nationale de la RechercheFrench National Research Agency (ANR) [2010-CSRD]; French Agence Nationale de la Recherche as part of the Investments for the Future programFrench National Research Agency (ANR) [ANR-10-IAHU-01]; La Ligue National contre le Cancer (France); Fondation ARC, France; Institut National du Cancer (INCA), FranceInstitut National du Cancer (INCA) France; German Federal Ministry of Education and ResearchFederal Ministry of Education & Research (BMBF) [BMBF 01 EO 0803]; Canadian Gene Cure Foundation and Finding of Rare Disease Genes (FORGE) Canada; National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [AI037526] ; This study was supported by the National Institute of Health and Medical Research, le fonds de recherche clinique du Ministere de la Sante, the European Union's Seventh Research and Technological Development Framework Programme (EUROPAD contract 201549 and ERC advanced grant PID-IMMUNE contract 249816), Association Contre Le Cancer, the Fondation pour la Recherche Medicale (grant number: ING20130526624), la Ligue Contre le Cancer (Comite de Paris) and the Agence Nationale de la Recherche (grant: 2010-CSRD) and a government grant managed by the French Agence Nationale de la Recherche as part of the Investments for the Future program (ANR-10-IAHU-01). This work in the Epigenetics group at the International Agency for Research on Cancer was supported by the La Ligue National contre le Cancer (France), Fondation ARC, France, and Institut National du Cancer (INCA), France. This study was also funded by the German Federal Ministry of Education and Research (grant: BMBF 01 EO 0803) and by the Canadian Gene Cure Foundation and Finding of Rare Disease Genes (FORGE) Canada. This work was supported in part by National Institutes of Health grant AI037526 to M.C.N. M.C.N. is a Howard Hughes Medical Institute investigator. S.K. is a Centre National de la Recherche Scientifique researcher.

WOS: 000352238600023 ; PubMed ID: 25312759 ; Background: Immunoglobulin class-switch recombination defects (CSR-D) are rare primary immunodeficiencies characterized by impaired production of switched immunoglobulin isotypes and normal or elevated IgM levels. They are caused by impaired T:B cooperation or intrinsic B cell defects. However, many immunoglobulin CSR-Ds are still undefined at the molecular level. Objective: This study's objective was to delineate new causes of immunoglobulin CSR-Ds and thus gain further insights into the process of immunoglobulin class-switch recombination (CSR). Methods: Exome sequencing in 2 immunoglobulin CSR-D patients identified variations in the INO80 gene. Functional experiments were performed to assess the function of INO80 on immunoglobulin CSR. Results: We identified recessive, nonsynonymous coding variations in the INO80 gene in 2 patients affected by defective immunoglobulin CSR. Expression of wild-type INO80 in patients' fibroblastic cells corrected their hypersensitivity to high doses of gamma-irradiation. In murine CH12-F3 cells, the INO80 complex accumulates at Sa and Em regions of the IgH locus, and downregulation of INO80 as well as its partners Reptin and Pontin impaired CSR. In addition, Reptin and Pontin were shown to interact with activation-induced cytidine deaminase. Finally, an abnormal separation of sister chromatids was observed upon INO80 downregulation in CH12-F3 cells, pinpointing its role in cohesin activity. Conclusion: INO80 deficiency appears to be associated with defective immunoglobulin CSR. We propose that the INO80 complex modulates cohesin function that may be required during immunoglobulin switch region synapsis. ; National Institute of Health and Medical ResearchInstitut National de la Sante et de la Recherche Medicale (Inserm); le fonds de recherche clinique du Ministere de la Sante; European Union (EUROPAD) [201549]; European Union (ERC advanced grant PID-IMMUNE) [249816]; Association Contre Le Cancer; Fondation pour la Recherche MedicaleFondation pour la Recherche Medicale [ING20130526624]; la Ligue Contre le Cancer (Comite de Paris); Agence Nationale de la RechercheFrench National Research Agency (ANR) [2010-CSRD]; French Agence Nationale de la Recherche as part of the Investments for the Future programFrench National Research Agency (ANR) [ANR-10-IAHU-01]; La Ligue National contre le Cancer (France); Fondation ARC, France; Institut National du Cancer (INCA), FranceInstitut National du Cancer (INCA) France; German Federal Ministry of Education and ResearchFederal Ministry of Education & Research (BMBF) [BMBF 01 EO 0803]; Canadian Gene Cure Foundation and Finding of Rare Disease Genes (FORGE) Canada; National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [AI037526] ; This study was supported by the National Institute of Health and Medical Research, le fonds de recherche clinique du Ministere de la Sante, the European Union's Seventh Research and Technological Development Framework Programme (EUROPAD contract 201549 and ERC advanced grant PID-IMMUNE contract 249816), Association Contre Le Cancer, the Fondation pour la Recherche Medicale (grant number: ING20130526624), la Ligue Contre le Cancer (Comite de Paris) and the Agence Nationale de la Recherche (grant: 2010-CSRD) and a government grant managed by the French Agence Nationale de la Recherche as part of the Investments for the Future program (ANR-10-IAHU-01). This work in the Epigenetics group at the International Agency for Research on Cancer was supported by the La Ligue National contre le Cancer (France), Fondation ARC, France, and Institut National du Cancer (INCA), France. This study was also funded by the German Federal Ministry of Education and Research (grant: BMBF 01 EO 0803) and by the Canadian Gene Cure Foundation and Finding of Rare Disease Genes (FORGE) Canada. This work was supported in part by National Institutes of Health grant AI037526 to M.C.N. M.C.N. is a Howard Hughes Medical Institute investigator. S.K. is a Centre National de la Recherche Scientifique researcher.

WOS: 000352238600023 ; PubMed ID: 25312759 ; Background: Immunoglobulin class-switch recombination defects (CSR-D) are rare primary immunodeficiencies characterized by impaired production of switched immunoglobulin isotypes and normal or elevated IgM levels. They are caused by impaired T:B cooperation or intrinsic B cell defects. However, many immunoglobulin CSR-Ds are still undefined at the molecular level. Objective: This study's objective was to delineate new causes of immunoglobulin CSR-Ds and thus gain further insights into the process of immunoglobulin class-switch recombination (CSR). Methods: Exome sequencing in 2 immunoglobulin CSR-D patients identified variations in the INO80 gene. Functional experiments were performed to assess the function of INO80 on immunoglobulin CSR. Results: We identified recessive, nonsynonymous coding variations in the INO80 gene in 2 patients affected by defective immunoglobulin CSR. Expression of wild-type INO80 in patients' fibroblastic cells corrected their hypersensitivity to high doses of gamma-irradiation. In murine CH12-F3 cells, the INO80 complex accumulates at Sa and Em regions of the IgH locus, and downregulation of INO80 as well as its partners Reptin and Pontin impaired CSR. In addition, Reptin and Pontin were shown to interact with activation-induced cytidine deaminase. Finally, an abnormal separation of sister chromatids was observed upon INO80 downregulation in CH12-F3 cells, pinpointing its role in cohesin activity. Conclusion: INO80 deficiency appears to be associated with defective immunoglobulin CSR. We propose that the INO80 complex modulates cohesin function that may be required during immunoglobulin switch region synapsis. ; National Institute of Health and Medical ResearchInstitut National de la Sante et de la Recherche Medicale (Inserm); le fonds de recherche clinique du Ministere de la Sante; European Union (EUROPAD) [201549]; European Union (ERC advanced grant PID-IMMUNE) [249816]; Association Contre Le Cancer; Fondation pour la Recherche MedicaleFondation pour la Recherche Medicale [ING20130526624]; la Ligue Contre le Cancer (Comite de Paris); Agence Nationale de la RechercheFrench National Research Agency (ANR) [2010-CSRD]; French Agence Nationale de la Recherche as part of the Investments for the Future programFrench National Research Agency (ANR) [ANR-10-IAHU-01]; La Ligue National contre le Cancer (France); Fondation ARC, France; Institut National du Cancer (INCA), FranceInstitut National du Cancer (INCA) France; German Federal Ministry of Education and ResearchFederal Ministry of Education & Research (BMBF) [BMBF 01 EO 0803]; Canadian Gene Cure Foundation and Finding of Rare Disease Genes (FORGE) Canada; National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [AI037526] ; This study was supported by the National Institute of Health and Medical Research, le fonds de recherche clinique du Ministere de la Sante, the European Union's Seventh Research and Technological Development Framework Programme (EUROPAD contract 201549 and ERC advanced grant PID-IMMUNE contract 249816), Association Contre Le Cancer, the Fondation pour la Recherche Medicale (grant number: ING20130526624), la Ligue Contre le Cancer (Comite de Paris) and the Agence Nationale de la Recherche (grant: 2010-CSRD) and a government grant managed by the French Agence Nationale de la Recherche as part of the Investments for the Future program (ANR-10-IAHU-01). This work in the Epigenetics group at the International Agency for Research on Cancer was supported by the La Ligue National contre le Cancer (France), Fondation ARC, France, and Institut National du Cancer (INCA), France. This study was also funded by the German Federal Ministry of Education and Research (grant: BMBF 01 EO 0803) and by the Canadian Gene Cure Foundation and Finding of Rare Disease Genes (FORGE) Canada. This work was supported in part by National Institutes of Health grant AI037526 to M.C.N. M.C.N. is a Howard Hughes Medical Institute investigator. S.K. is a Centre National de la Recherche Scientifique researcher.

BACKGROUND: Activated phosphoinositide 3-kinase δ syndrome (APDS) is a recently described combined immunodeficiency resulting from gain-of-function mutations in PIK3CD, the gene encoding the catalytic subunit of phosphoinositide 3-kinase δ (PI3Kδ). OBJECTIVE: We sought to review the clinical, immunologic, histopathologic, and radiologic features of APDS in a large genetically defined international cohort. METHODS: We applied a clinical questionnaire and performed review of medical notes, radiology, histopathology, and laboratory investigations of 53 patients with APDS. RESULTS: Recurrent sinopulmonary infections (98%) and nonneoplastic lymphoproliferation (75%) were common, often from childhood. Other significant complications included herpesvirus infections (49%), autoinflammatory disease (34%), and lymphoma (13%). Unexpectedly, neurodevelopmental delay occurred in 19% of the cohort, suggesting a role for PI3Kδ in the central nervous system; consistent with this, PI3Kδ is broadly expressed in the developing murine central nervous system. Thoracic imaging revealed high rates of mosaic attenuation (90%) and bronchiectasis (60%). Increased IgM levels (78%), IgG deficiency (43%), and CD4 lymphopenia (84%) were significant immunologic features. No immunologic marker reliably predicted clinical severity, which ranged from asymptomatic to death in early childhood. The majority of patients received immunoglobulin replacement and antibiotic prophylaxis, and 5 patients underwent hematopoietic stem cell transplantation. Five patients died from complications of APDS. CONCLUSION: APDS is a combined immunodeficiency with multiple clinical manifestations, many with incomplete penetrance and others with variable expressivity. The severity of complications in some patients supports consideration of hematopoietic stem cell transplantation for severe childhood disease. Clinical trials of selective PI3Kδ inhibitors offer new prospects for APDS treatment. ; T.C. is supported by National Children's Research Centre, Our Lady's Children's Hospital Crumlin, Dublin, Ireland. A.C. has a Wellcome Trust Postdoctoral Training Fellowship for Clinicians (103413/Z/13/Z). K.O. is supported by funding from BBSRC, MRC, Wellcome Trust and GSK. R.D. and D.S.K are funded by National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre, Cambridge, UK. C.S. and S.E. are supported by the German Federal Ministry of Education and Research (BMBF 01 EO 0803 grant to the Center of Chronic immunodeficiency and BMBF 01GM1111B grant to the PID-NET initiative). S.N.F is supported in part by the Southampton UK National Institute for Health Research (NIHR) Wellcome Trust Clinical Research Facility and NIHR Respiratory Biomedical Research Unit. M.A.A.I. is funded by NHS Innovation London and King's College Hospital Charitable Trust. A.F., S.L., A.D., F.R-L and S.K. are supported by the European Union's 7th RTD Framework Programme (ERC advanced grant PID-IMMUNE contract 249816) and a government grant managed by the French Agence Nationale de la Recherche as part of the "Investments for the Future" program (ANR-10-IAHU-01). S.L. is supported by the Agence Nationale de la Recherche (ANR) (ANR-14-CE14-0028-01), the Foundation ARC pour la Recherche sur le Cancer (France), the Rare Diseases Foundation (France) and François Aupetit Association (France). S.L. is a senior scientist and S.K is a researcher at the Centre National de la Recherche Scientifique-CNRS (France). A.D. and S.K. are supported by the "Institut National de la Santé et de la Recherche Médicale". S.K. also supported by the Fondation pour la Recherche Médicale (grant number: ING20130526624), la Ligue Contre le Cancer (Comité de Paris) and the Centre de Référence Déficits Immunitaires Héréditaires (CEREDIH). S.O.B is supported by the Higher Education Funding Council for England. B.V. is supported by the UK Biotechnology and Biological Sciences Research Council [BB/I007806/1], Cancer Research UK [C23338/A15965) and the National Institute for Health Research (NIHR) University College London Hospitals Biomedical Research Centre. B.V. is consultant to Karus Therapeutics (Oxford, UK). S.N. is a Wellcome Trust Senior Research Fellow in Basic Biomedical Science (095198/Z/10/Z). S.N. is also supported by the European Research Council Starting grant 260477, the EU FP7 collaborative grant 261441 (PEVNET project) and the National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre, UK. A.M.C. is funded by the Medical Research Council, British Lung Foundation, University of Sheffield and Cambridge NIHR-BRC. Research in A.M.C. laboratory has received non-commercial grant support from GSK, Novartis, and MedImmune. ; This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.jaci.2016.06.021