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1دورية أكاديمية
المؤلفون: Andrey Kulikov, Elena Shipaeva, Anastasia Dmitrieva, Vera Batrak, Georgy Shipunov, Colin Guy, Jill Smith, Ran Zhang, Michael Zhang, Jeff Duan, Anton Chestukhin, Sergei Barbashov, Mikhail Samsonov, Yan Lavrovsky
المصدر: Frontiers in Pharmacology, Vol 12 (2021)
مصطلحات موضوعية: cancer immunotherapy, monoclonal antibody, PD-L1, in vitro efficacy, animal models, therapeutic agent, Therapeutics. Pharmacology, RM1-950
الوصف: RPH-120 is a novel fully human anti-PD-L1 IgG1 monoclonal antibody with specifically designed Asn300Ala mutation in Fc fragment. Surface plasmon resonance assay showed that affinity of the RPH-120 to the dimeric form of human PD-L1-Fc fusion protein was much higher than affinity to the monomeric His-tagged PD-L1. Further binding studies demonstrated that RPH-120 is able to bind to human and monkey but not mouse PD-L1. Tissue cross-reactivity study showed good comparability of human and Cynomolgus monkeys tissue staining. Bioactivity was assessed using mixed lymphocyte reaction assay. This study revealed that RPH-120 was able to activate T cells preventing PD1/PD-L1 interaction. Antitumor efficacy was analyzed in HCC-827 lung cancer xenografts in humanized CD34+ mice at three dosage levels: 20, 80, and 200 mg/kg. RPH-120 demonstrated significant tumor growth inhibition, and this inhibition was comparable to that of atezolizumab. In a single dose toxicity, toxicokinetic and dose range finding study performed in Cynomolgus monkeys, RPH-120 was administered via intravenous (IV) bolus or 60-min IV infusion, followed by 8-weeks recovery period. An acceptable toxicokinetic profile was demonstrated and administration at doses of up to 200 mg/kg was well tolerated by all animals. In conclusion, RPH-120 revealed promising in vitro and in vivo activity and safety. RPH-120 is a potent anti-PD-L1 drug candidate for cancer immunotherapy.
وصف الملف: electronic resource
العلاقة: https://www.frontiersin.org/articles/10.3389/fphar.2021.723038/fullTest; https://doaj.org/toc/1663-9812Test
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2دورية أكاديميةA cis-acting diversification activator both necessary and sufficient for AID-mediated hypermutation.
المؤلفون: Artem Blagodatski, Vera Batrak, Sabine Schmidl, Ulrike Schoetz, Randolph B Caldwell, Hiroshi Arakawa, Jean-Marie Buerstedde
المصدر: PLoS Genetics, Vol 5, Iss 1, p e1000332 (2009)
الوصف: Hypermutation of the immunoglobulin (Ig) genes requires Activation Induced cytidine Deaminase (AID) and transcription, but it remains unclear why other transcribed genes of B cells do not mutate. We describe a reporter transgene crippled by hypermutation when inserted into or near the Ig light chain (IgL) locus of the DT40 B cell line yet stably expressed when inserted into other chromosomal positions. Step-wise deletions of the IgL locus revealed that a sequence extending for 9.8 kilobases downstream of the IgL transcription start site confers the hypermutation activity. This sequence, named DIVAC for diversification activator, efficiently activates hypermutation when inserted at non-Ig loci. The results significantly extend previously reported findings on AID-mediated gene diversification. They show by both deletion and insertion analyses that cis-acting sequences predispose neighboring transcription units to hypermutation.
وصف الملف: electronic resource
العلاقة: http://europepmc.org/articles/PMC2607555?pdf=renderTest; https://doaj.org/toc/1553-7390Test; https://doaj.org/toc/1553-7404Test
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3مؤتمر
المؤلفون: Andrey Kulikov (4871602), Elena Shipaeva (11258712), Anastasia Dmitrieva (11258715), Vera Batrak (267991), Georgy Shipunov (11258718), Colin Guy (3136320), Jill Smith (2694001), Ran Zhang (117374), Michael Zhang (196907), Jeff Duan (11258721), Anton Chestukhin (11258724), Sergei Barbashov (11258727), Mikhail Samsonov (11258730), Yan Lavrovsky (2390548)
مصطلحات موضوعية: Pharmacology, Basic Pharmacology, Clinical Pharmacology and Therapeutics, Clinical Pharmacy and Pharmacy Practice, Pharmaceutical Sciences, Pharmacogenomics, Toxicology (incl. Clinical Toxicology), Pharmacology and Pharmaceutical Sciences not elsewhere classified, cancer immunotherapy, monoclonal antibody, PD-L1, in vitro efficacy, animal models, therapeutic agent
الوصف: RPH-120 is a novel fully human anti-PD-L1 IgG1 monoclonal antibody with specifically designed Asn300Ala mutation in Fc fragment. Surface plasmon resonance assay showed that affinity of the RPH-120 to the dimeric form of human PD-L1-Fc fusion protein was much higher than affinity to the monomeric His-tagged PD-L1. Further binding studies demonstrated that RPH-120 is able to bind to human and monkey but not mouse PD-L1. Tissue cross-reactivity study showed good comparability of human and Cynomolgus monkeys tissue staining. Bioactivity was assessed using mixed lymphocyte reaction assay. This study revealed that RPH-120 was able to activate T cells preventing PD1/PD-L1 interaction. Antitumor efficacy was analyzed in HCC-827 lung cancer xenografts in humanized CD34 + mice at three dosage levels: 20, 80, and 200 mg/kg. RPH-120 demonstrated significant tumor growth inhibition, and this inhibition was comparable to that of atezolizumab. In a single dose toxicity, toxicokinetic and dose range finding study performed in Cynomolgus monkeys, RPH-120 was administered via intravenous (IV) bolus or 60-min IV infusion, followed by 8-weeks recovery period. An acceptable toxicokinetic profile was demonstrated and administration at doses of up to 200 mg/kg was well tolerated by all animals. In conclusion, RPH-120 revealed promising in vitro and in vivo activity and safety. RPH-120 is a potent anti-PD-L1 drug candidate for cancer immunotherapy.
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4دورية أكاديمية
المؤلفون: Artem Blagodatski, Vera Batrak, Sabine Schmidl, Ulrike Schoetz, Olph B. Caldwell, Jean-marie Buerstedde
المساهمون: The Pennsylvania State University CiteSeerX Archives
المصدر: ftp://ftp.ncbi.nlm.nih.gov/pub/pmc/44/ce/PLoS_Genet_2009_Jan_9_5(1)_e1000332.tar.gz
مصطلحات موضوعية: These authors contributed equally to this work
الوصف: Hypermutation of the immunoglobulin (Ig) genes requires Activation Induced cytidine Deaminase (AID) and transcription, but it remains unclear why other transcribed genes of B cells do not mutate. We describe a reporter transgene crippled by hypermutation when inserted into or near the Ig light chain (IgL) locus of the DT40 B cell line yet stably expressed when inserted into other chromosomal positions. Step-wise deletions of the IgL locus revealed that a sequence extending for 9.8 kilobases downstream of the IgL transcription start site confers the hypermutation activity. This sequence, named DIVAC for diversification activator, efficiently activates hypermutation when inserted at non-Ig loci. The results significantly extend previously reported findings on AID-mediated gene diversification. They show by both deletion and insertion analyses that
وصف الملف: application/zip
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5دورية أكاديمية
المؤلفون: Hiroshi Arakawa, Hiroaki Kudo, Vera Batrak, Olph B. Caldwell, Michael A. Rieger, Joachim W. Ellwart, Jean-marie Buerstedde
المساهمون: The Pennsylvania State University CiteSeerX Archives
الوصف: in the B cell line DT40
وصف الملف: application/pdf
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6
المؤلفون: Vera, Batrak, Artem, Blagodatski, Jean-Marie, Buerstedde
المصدر: Methods in molecular biology (Clifton, N.J.). 745
مصطلحات موضوعية: Cell Line, Tumor, Mutation, Animals, Immunoglobulins, Immunoglobulin Light Chains, Somatic Hypermutation, Immunoglobulin, Flow Cytometry, Chickens, Polymerase Chain Reaction
الوصف: The immunoglobulin (Ig) genes of B cells are diversified at high rate by point mutations whereas the non-Ig genes of B cells accumulate no or significantly fewer mutations. Ig hypermutations are critical for the affinity maturation of antibodies for most of jawed vertebrates and also contribute to the primary Ig diversity repertoire formation in some species. How the hypermutation activity is specifically targeted to the Ig loci is a long-standing debate. Here we describe a new experimental approach to investigate the locus specificity of Ig hypermutation using the chicken B-cell line DT40. One feature is the use of a green fluorescent protein (GFP) gene as a mutation reporter. Some nucleotide changes produced by somatic hypermutation can cripple the GFP gene which leads to a decrease or loss of the green fluorescence. Therefore such changes can be easily quantified by fluorescence-activated cell sorting (FACS). Another advantage of this approach is the targeted integration of the mutation reporter into a defined chromosomal position. This system allowed us to identify a 10 kb sequence within the Ig light chain (IgL) locus, which is both necessary and sufficient to activate hypermutation in the neighboring reporter gene. We have called this sequence Diversification Activator (DIVAC) and postulated that similar cis-acting sequences exist in the heavy and light chain Ig loci of all jawed vertebrate species. Our experimental system promises further insight into the molecular mechanism of Ig hypermutation. For example, it may be possible to identify smaller functional motifs within DIVAC and address the role of putative transacting binding factors by gene knock-outs.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::f8674eaddf727767614b6b5d9912a425Test
https://pubmed.ncbi.nlm.nih.gov/21660702Test -
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المؤلفون: Jean-Marie Buerstedde, Vera Batrak, Artem Blagodatski
المصدر: Methods in Molecular Biology ISBN: 9781617791284
مصطلحات موضوعية: Affinity maturation, Genetics, Reporter gene, Point mutation, Somatic hypermutation, Locus (genetics), Biology, Immunoglobulin light chain, Gene, Green fluorescent protein
الوصف: The immunoglobulin (Ig) genes of B cells are diversified at high rate by point mutations whereas the non-Ig genes of B cells accumulate no or significantly fewer mutations. Ig hypermutations are critical for the affinity maturation of antibodies for most of jawed vertebrates and also contribute to the primary Ig diversity repertoire formation in some species. How the hypermutation activity is specifically targeted to the Ig loci is a long-standing debate. Here we describe a new experimental approach to investigate the locus specificity of Ig hypermutation using the chicken B-cell line DT40. One feature is the use of a green fluorescent protein (GFP) gene as a mutation reporter. Some nucleotide changes produced by somatic hypermutation can cripple the GFP gene which leads to a decrease or loss of the green fluorescence. Therefore such changes can be easily quantified by fluorescence-activated cell sorting (FACS). Another advantage of this approach is the targeted integration of the mutation reporter into a defined chromosomal position. This system allowed us to identify a 10 kb sequence within the Ig light chain (IgL) locus, which is both necessary and sufficient to activate hypermutation in the neighboring reporter gene. We have called this sequence Diversification Activator (DIVAC) and postulated that similar cis-acting sequences exist in the heavy and light chain Ig loci of all jawed vertebrate species. Our experimental system promises further insight into the molecular mechanism of Ig hypermutation. For example, it may be possible to identify smaller functional motifs within DIVAC and address the role of putative transacting binding factors by gene knock-outs.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::993d43407b78dfcb187bc0810a1156c3Test
https://doi.org/10.1007/978-1-61779-129-1_18Test -
8
المؤلفون: Artem Blagodatski, Jean-Marie Buerstedde, Sabine Schmidl, Hiroshi Arakawa, Ulrike Schoetz, Vera Batrak, Randolph B. Caldwell
المصدر: PLoS Genetics
PLoS Genetics, Vol 5, Iss 1, p e1000332 (2009)
PLoS Genet. 5:e1000332 (2009)مصطلحات موضوعية: Cancer Research, lcsh:QH426-470, Green Fluorescent Proteins, Somatic hypermutation, Locus (genetics), Regulatory Sequences, Nucleic Acid, Transfection, Transcription (biology), Genes, Reporter, Cytidine Deaminase, Genetics, Activation-induced (cytidine) deaminase, Animals, Insertion, Gene, Molecular Biology, Genetics (clinical), Ecology, Evolution, Behavior and Systematics, AID, B cell, DT40, enhancer, gene conversion, immunoglobulin, somatic hypermutation, transcription, B-Lymphocytes, biology, Activator (genetics), Chromosome Mapping, Genetic Variation, Cytidine deaminase, Sequence Analysis, DNA, Cell Biology, Flow Cytometry, lcsh:Genetics, Gene Expression Regulation, Mutation, biology.protein, Genetics and Genomics/Genetics of the Immune System, Genes, Immunoglobulin Light Chain, Somatic Hypermutation, Immunoglobulin, Immunology/Genetics of the Immune System, Chickens, Gene Deletion, Research Article, Biotechnology
الوصف: Hypermutation of the immunoglobulin (Ig) genes requires Activation Induced cytidine Deaminase (AID) and transcription, but it remains unclear why other transcribed genes of B cells do not mutate. We describe a reporter transgene crippled by hypermutation when inserted into or near the Ig light chain (IgL) locus of the DT40 B cell line yet stably expressed when inserted into other chromosomal positions. Step-wise deletions of the IgL locus revealed that a sequence extending for 9.8 kilobases downstream of the IgL transcription start site confers the hypermutation activity. This sequence, named DIVAC for diversification activator, efficiently activates hypermutation when inserted at non-Ig loci. The results significantly extend previously reported findings on AID-mediated gene diversification. They show by both deletion and insertion analyses that cis-acting sequences predispose neighboring transcription units to hypermutation.
Author Summary It remains an open question how AID-mediated gene diversification is targeted to the immunoglobulin loci. Here we define a cis-acting sequence, named DIVAC for diversification activator, which is required for hypermutation of the Ig light chain gene and sufficient to activate hypermutation at various non-Ig loci in the DT40 B cell line. DIVAC is composed of multiple interacting sequences and able to work over considerable distances both upstream and downstream of its target gene. This work provides the first conclusive evidence that AID-mediated gene diversification is targeted to the Ig loci by cis-acting sequences. The conservation of AID-mediated Ig gene diversification during vertebrate evolution suggests that DIVACs also play a role in gene conversion, hypermutation, and switch recombination in mammalian B cells. The findings should be of general interest not only for molecular immunology and the pathogenesis of B cell lymphomas but also the whole field of biology as a unique example of how locus-specific gene diversification is controlled. The described experimental system offers unique advantages to further clarify the molecular mechanism of DIVAC.وصف الملف: application/pdf
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3c9303381e5327b68fc6465265d13502Test
https://pubmed.ncbi.nlm.nih.gov/19132090Test
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