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.