ELUCIDATION OF IMMUNOGLOBULIN CLASS SWITCH RECOMBINATION AND SOMATIC HYPERMUTATIO
Jayanta Chaudhuri, Assistant Member
Sloan-kettering Institute For Cancer Res, 1275 York Ave, New York, Ny 10065
Grant 1R01AI072194-01A2 from National Institute Of Allergy And Infectious Diseases
Abstract: To mount an optimum immune response, mature B lymphocytes undergo two genetic alterations in the forms of class switch recombination (CSR) and somatic hypermutation (SHM). CSR leads to the production of antibodies of various isotypes (IgG, IgE, IgA) while SHM results in the generation of antibody molecules with a much higher affinity for antigens. The B cell specific protein AID (activation induced deaminase) is essential to both processes. AID initiates CSR and SHM by deaminating cytidines within transcribed regions of the immunoglobulin locus. These lesions are then converted into point mutations during SHM or into DNA double strand breaks that serve as obligatory intermediates during CSR. Inactivation of AID leads to human immunodeficiency syndromes (Hyper-IgM2) where patients suffer from profound susceptibility to bacterial infections. On the other hand, deregulation of AID converts it into a general mutator and leads to mutations and translocations of oncogenes that have been implicated in mature B cell lymphomagenesis. An understanding of the processes that regulate AID activity is thus of utmost importance. The overall objective of this research proposal is to elucidate the mechanism by which AID activity is regulated during CSR and SHM. Recent studies have shown that protein kinase A (PKA) phosphorylates AID in vitro to activate its ability to bind its cofactor, the single-stand DNA binding protein Replication Protein A and mediate deamination of transcribed DNA substrates. To elucidate the role of AID phosphorylation in vivo, mice with a mutation in the AID phosphorylation site will be generated and analyzed for CSR and SHM. The mutant mouse will also be used in cellular and biochemical assays to delineate the function of phosphorylated AID in CSR and SHM. Finally, existing PKA mutants will be analyzed to test the hypothesis that AID phosphorylation by PKA is itself a highly regulated event and could potentially contribute to AID target specificity. Successful completion of the projects outlined in this proposal will provide mechanistic insights into reactions central to immunity and how aberrations in such physiological reactions can cause mature B cell tumors. B cell lymphomas are the most common human malignancies. It is now clear that a large majority of B cell tumors arise due to mistargeted AID activity. Experiments proposed here will elucidate the role of AID in both immunity and cancer
Keywords: 3`5`-cyclic ester of AMP; AICDA; AICDA protein; ATGN; Address; Adenosine Cyclic 3`, 5`-Monophosphate; Adenosine Cyclic Monophosphate; Adenosine Cyclic Monophosphate-Dependent Protein Kinases; Adenosine, cyclic 3`, 5`-(hydrogen phosphate); Affect; Affinity; Alanine; Alanine, L-Isomer; Antibodies; Antibody Formation; Antibody Production; Antibody Response; Antigens; Assay; B blood cells; B cell tumor; B lymphoma; B-Cell Lymphocytic Neoplasm; B-Cell Lymphomas; B-Cell Neoplasm; B-Cell Non-Hodgkin`s Lymphoma; B-Cell NonHodgkins Lymphoma; B-Cells; B-Lymphocytes; B-lineage tumor; Bacterial Infections; Binding; Binding (Molecular Function); Binding Proteins; Bioassay; Biochemical; Biologic Assays; Biological Assay; Bursa-Dependent Lymphocytes; Bursa-Equivalent Lymphocyte; CDA2 protein; Cancer Genes; Cancer-Promoting Gene; Cancers; Catalytic Core; Catalytic Domain; Catalytic Region; Catalytic Site; Catalytic Subunit; Cells; Chromatin; Class Switching; Complex; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cytidine; Cytosine Ribonucleoside; Cytosine Riboside; DNA; DNA Double Strand Break; DNA Recombination; DNA recombination (naturally occurring); DNA replication factor A; DNA-Binding Proteins; Deaminase; Deamination; Deoxyribonucleic Acid; Double Strand Break Repair; EC 2.7; Elements; Enzyme Activation; Event; Future; Gamma Globulin, 19S; Gamma Globulin, 7S; Generations; Genes; Genetic Alteration; Genetic Change; Genetic Recombination; Genetic defect; Hand; Holoenzymes; Human; Human, General; Ig Somatic Hypermutation; IgA; IgE; IgG; IgM; Immune Globulins; Immune response; Immunity; Immunodeficiency Disorder; Immunodeficiency Syndrome; Immunoglobulin A; Immunoglobulin Class Switching; Immunoglobulin E; Immunoglobulin G; Immunoglobulin Isotype-Switch Recombination; Immunoglobulin M; Immunoglobulin Somatic Hypermutation; Immunoglobulin Switch Recombination; Immunoglobulins; Immunoglobulins / Antibodies; Immunologic Deficiency Syndromes; Immunological Deficiency Syndromes; In Vitro; Isotype Switching; Kinases; Knock-in; Knock-in Mouse; L-Alanine; L-Serine; Lead; Lesion; Ligand Binding Protein; Light; Lymphomagenesis; Malignant Neoplasms; Malignant Tumor; Mammals, Mice; Man (Taxonomy); Man, Modern; Mature B-Cell; Mature B-Lymphocyte; Measures; Mediating; Mice; Mice, Mutant Strains; Modeling; Molecular Interaction; Murine; Mus; Mutant Strains Mice; Mutation; Oncogenes; PKA; Patients; Pb element; Phosphoproteins; Phosphorylation; Phosphorylation Site; Phosphotransferases; Photoradiation; Physiologic; Physiological; Play; Point Mutation; Post-Translational Modifications; Post-Translational Protein Processing; Posttranslational Modifications; Predisposition; Process; Protein Kinase A; Protein Modification; Protein Modification, Post-Translational; Protein Phosphorylation; Protein Processing, Post-Translational; Protein Processing, Posttranslational; Protein/Amino Acid Biochemistry, Post-Translational Modification; Proteins; Public Health; Reaction; Recombination; Recombination, Genetic; Recruitment Activity; Regulatory Protein; Repetitive Element; Repetitive Regions; Repetitive Sequence; Reporting; Research Proposals; Role; Series; Serine; Single-Stranded DNA; Somatic Hypermutation, Immunoglobulin; Specificity; Susceptibility; Switch Recombination; Switchings, Class; Switchings, Immunoglobulin Class; Switchings, Isotype; Testing; Transforming Genes; Transphosphorylases; Urd; Uridine; activation-induced cytidine deaminase; activation-induced deaminase; adenosine 3`5` monophosphate; antibody biosynthesis; antigen binding; bacterial disease; base; cAMP; cAMP-Dependent Protein Kinases; cofactor; constant region gene; design; designing; experiment; experimental research; experimental study; gene product; genetic regulatory protein; genome mutation; heavy metal Pb; heavy metal lead; host response; hypoimmunity; immune deficiency disorder; immunodeficiency; immunogen; immunoglobulin biosynthesis; immunoresponse; in vivo; insight; malignancy; mouse mutant; mutant; neoplasm/cancer; novel; prevent; preventing; protein activation; public health medicine (field); public health relevance; recruit; regulatory gene product; repair; repaired; replication factor A; replication protein A; research study; single-strand binding protein RP-A; social role; somatic hypermutation; stem
Relevance: RELEVANCE TO PUBLIC HEALTH B cell lymphomas are the most common human malignancies. It is now clear that a large majority of B cell tumors arise due to mistargeted AID activity. Experiments proposed here will elucidate the role of AID in both immunity and cancer
Project start date: 2009-07-01
Project end date: 2014-06-30
Budget start date: 1-JUL-2009
Budget end date: 30-JUN-2010
PFA/PA: PA-07-070
1R01AI072194-01A2 (2009): $474000
Sponsored Links Excellgen http://Excellgen.com
Grants awarded to Jayanta Chaudhuri
ELUCIDATION OF IMMUNOGLOBULIN CLASS SWITCH RECOMBINATION AND SOMATIC HYPERMUTATIO
Jayanta Chaudhuri, Assistant Member
Sloan-kettering Institute For Cancer Res, 1275 York Ave, New York, Ny 10065
Grant 5R01AI072194-02 from National Institute Of Allergy And Infectious Diseases
Abstract: To mount an optimum immune response, mature B lymphocytes undergo two genetic alterations in the forms of class switch recombination (CSR) and somatic hypermutation (SHM). CSR leads to the production of antibodies of various isotypes (IgG, IgE, IgA) while SHM results in the generation of antibody molecules with a much higher affinity for antigens. The B cell specific protein AID (activation induced deaminase) is essential to both processes. AID initiates CSR and SHM by deaminating cytidines within transcribed regions of the immunoglobulin locus. These lesions are then converted into point mutations during SHM or into DNA double strand breaks that serve as obligatory intermediates during CSR. Inactivation of AID leads to human immunodeficiency syndromes (Hyper-IgM2) where patients suffer from profound susceptibility to bacterial infections. On the other hand, deregulation of AID converts it into a general mutator and leads to mutations and translocations of oncogenes that have been implicated in mature B cell lymphomagenesis. An understanding of the processes that regulate AID activity is thus of utmost importance. The overall objective of this research proposal is to elucidate the mechanism by which AID activity is regulated during CSR and SHM. Recent studies have shown that protein kinase A (PKA) phosphorylates AID in vitro to activate its ability to bind its cofactor, the single-stand DNA binding protein Replication Protein A and mediate deamination of transcribed DNA substrates. To elucidate the role of AID phosphorylation in vivo, mice with a mutation in the AID phosphorylation site will be generated and analyzed for CSR and SHM. The mutant mouse will also be used in cellular and biochemical assays to delineate the function of phosphorylated AID in CSR and SHM. Finally, existing PKA mutants will be analyzed to test the hypothesis that AID phosphorylation by PKA is itself a highly regulated event and could potentially contribute to AID target specificity. Successful completion of the projects outlined in this proposal will provide mechanistic insights into reactions central to immunity and how aberrations in such physiological reactions can cause mature B cell tumors. B cell lymphomas are the most common human malignancies. It is now clear that a large majority of B cell tumors arise due to mistargeted AID activity. Experiments proposed here will elucidate the role of AID in both immunity and cancer
Keywords: 3`5`-cyclic ester of AMP; AICDA; AICDA protein; ATGN; Address; Adenosine Cyclic 3`, 5`-Monophosphate; Adenosine Cyclic Monophosphate; Adenosine Cyclic Monophosphate-Dependent Protein Kinases; Adenosine, cyclic 3`, 5`-(hydrogen phosphate); Affect; Affinity; Alanine; Alanine, L-Isomer; Antibodies; Antibody Formation; Antibody Production; Antibody Response; Antigens; Assay; B blood cells; B cell tumor; B lymphoma; B-Cell Lymphocytic Neoplasm; B-Cell Lymphomas; B-Cell Neoplasm; B-Cell Non-Hodgkin`s Lymphoma; B-Cell NonHodgkins Lymphoma; B-Cells; B-Lymphocytes; B-lineage tumor; Bacterial Infections; Binding; Binding (Molecular Function); Binding Proteins; Bioassay; Biochemical; Biologic Assays; Biological Assay; Bursa-Dependent Lymphocytes; Bursa-Equivalent Lymphocyte; CDA2 protein; Cancer Genes; Cancer-Promoting Gene; Cancers; Catalytic Core; Catalytic Domain; Catalytic Region; Catalytic Site; Catalytic Subunit; Cells; Chromatin; Class Switching; Complex; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cytidine; Cytosine Ribonucleoside; Cytosine Riboside; DNA; DNA Double Strand Break; DNA Recombination; DNA recombination (naturally occurring); DNA replication factor A; DNA-Binding Proteins; Deaminase; Deamination; Deoxyribonucleic Acid; Double Strand Break Repair; EC 2.7; Elements; Enzyme Activation; Event; Future; Gamma Globulin, 19S; Gamma Globulin, 7S; Generations; Genes; Genetic Alteration; Genetic Change; Genetic Recombination; Genetic defect; Hand; Holoenzymes; Human; Human, General; Ig Somatic Hypermutation; IgA; IgE; IgG; IgM; Immune Globulins; Immune response; Immunity; Immunodeficiency Disorder; Immunodeficiency Syndrome; Immunoglobulin A; Immunoglobulin Class Switching; Immunoglobulin E; Immunoglobulin G; Immunoglobulin Isotype-Switch Recombination; Immunoglobulin M; Immunoglobulin Somatic Hypermutation; Immunoglobulin Switch Recombination; Immunoglobulins; Immunoglobulins / Antibodies; Immunologic Deficiency Syndromes; Immunological Deficiency Syndromes; In Vitro; Isotype Switching; Kinases; Knock-in; Knock-in Mouse; L-Alanine; L-Serine; Lead; Lesion; Ligand Binding Protein; Light; Lymphomagenesis; Malignant Neoplasms; Malignant Tumor; Mammals, Mice; Man (Taxonomy); Man, Modern; Mature B-Cell; Mature B-Lymphocyte; Measures; Mediating; Mice; Mice, Mutant Strains; Modeling; Molecular Interaction; Murine; Mus; Mutant Strains Mice; Mutation; Oncogenes; PKA; Patients; Pb element; Phosphoproteins; Phosphorylation; Phosphorylation Site; Phosphotransferases; Photoradiation; Physiologic; Physiological; Play; Point Mutation; Post-Translational Modifications; Post-Translational Protein Processing; Posttranslational Modifications; Predisposition; Process; Protein Kinase A; Protein Modification; Protein Modification, Post-Translational; Protein Phosphorylation; Protein Processing, Post-Translational; Protein Processing, Posttranslational; Protein/Amino Acid Biochemistry, Post-Translational Modification; Proteins; Public Health; Reaction; Recombination; Recombination, Genetic; Recruitment Activity; Regulatory Protein; Repetitive Element; Repetitive Regions; Repetitive Sequence; Reporting; Research Proposals; Role; Series; Serine; Single-Stranded DNA; Somatic Hypermutation, Immunoglobulin; Specificity; Susceptibility; Switch Recombination; Switchings, Class; Switchings, Immunoglobulin Class; Switchings, Isotype; Testing; Transforming Genes; Transphosphorylases; Urd; Uridine; activation-induced cytidine deaminase; activation-induced deaminase; adenosine 3`5` monophosphate; antibody biosynthesis; antigen binding; bacterial disease; base; cAMP; cAMP-Dependent Protein Kinases; cofactor; constant region gene; design; designing; experiment; experimental research; experimental study; gene product; genetic regulatory protein; genome mutation; heavy metal Pb; heavy metal lead; host response; hypoimmunity; immune deficiency disorder; immunodeficiency; immunogen; immunoglobulin biosynthesis; immunoresponse; in vivo; insight; malignancy; mouse mutant; mutant; neoplasm/cancer; novel; prevent; preventing; protein activation; public health medicine (field); public health relevance; recruit; regulatory gene product; repair; repaired; replication factor A; replication protein A; research study; single-strand binding protein RP-A; social role; somatic hypermutation; stem
Relevance: RELEVANCE TO PUBLIC HEALTH B cell lymphomas are the most common human malignancies. It is now clear that a large majority of B cell tumors arise due to mistargeted AID activity. Experiments proposed here will elucidate the role of AID in both immunity and cancer
Project start date: 2009-07-01
Project end date: 2014-06-30
Budget start date: 1-JUL-2010
Budget end date: 30-JUN-2011
PFA/PA: PA-07-070
5R01AI072194-02 (2010): $469260