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Gavade A, Nagraj AK, Patel R, Pais R, Dhanure P, Scheele J, Seiz W, Patil J. Understanding the Specific Implications of Amino Acids in the Antibody Development. Protein J 2024; 43:405-424. [PMID: 38724751 DOI: 10.1007/s10930-024-10201-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2024] [Indexed: 06/01/2024]
Abstract
As the demand for immunotherapy to treat and manage cancers, infectious diseases and other disorders grows, a comprehensive understanding of amino acids and their intricate role in antibody engineering has become a prime requirement. Naturally produced antibodies may not have the most suitable amino acids at the complementarity determining regions (CDR) and framework regions, for therapeutic purposes. Therefore, to enhance the binding affinity and therapeutic properties of an antibody, the specific impact of certain amino acids on the antibody's architecture must be thoroughly studied. In antibody engineering, it is crucial to identify the key amino acid residues that significantly contribute to improving antibody properties. Therapeutic antibodies with higher binding affinity and improved functionality can be achieved through modifications or substitutions with highly suitable amino acid residues. Here, we have indicated the frequency of amino acids and their association with the binding free energy in CDRs. The review also analyzes the experimental outcome of two studies that reveal the frequency of amino acids in CDRs and provides their significant correlation between the outcomes. Additionally, it discusses the various bond interactions within the antibody structure and antigen binding. A detailed understanding of these amino acid properties should assist in the analysis of antibody sequences and structures needed for designing and enhancing the overall performance of therapeutic antibodies.
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Affiliation(s)
- Akshata Gavade
- Innoplexus Consulting Services Pvt Ltd, 7Th Floor, Midas Tower, Hinjawadi, Pune, Maharashtra, 411057, India
| | - Anil Kumar Nagraj
- Innoplexus Consulting Services Pvt Ltd, 7Th Floor, Midas Tower, Hinjawadi, Pune, Maharashtra, 411057, India
| | - Riya Patel
- Innoplexus Consulting Services Pvt Ltd, 7Th Floor, Midas Tower, Hinjawadi, Pune, Maharashtra, 411057, India
| | - Roylan Pais
- Innoplexus Consulting Services Pvt Ltd, 7Th Floor, Midas Tower, Hinjawadi, Pune, Maharashtra, 411057, India
| | - Pratiksha Dhanure
- Innoplexus Consulting Services Pvt Ltd, 7Th Floor, Midas Tower, Hinjawadi, Pune, Maharashtra, 411057, India
| | | | | | - Jaspal Patil
- Innoplexus Consulting Services Pvt Ltd, 7Th Floor, Midas Tower, Hinjawadi, Pune, Maharashtra, 411057, India.
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Balla B, Tripon F, Lazar E, Bănescu C. Analysis of Mutational Status of IGHV, and Cytokine Polymorphisms as Prognostic Factors in Chronic Lymphocytic Leukemia: The Romanian Experience. Int J Mol Sci 2024; 25:1799. [PMID: 38339076 PMCID: PMC10855205 DOI: 10.3390/ijms25031799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/29/2024] [Accepted: 01/29/2024] [Indexed: 02/12/2024] Open
Abstract
The aim of the current study was to assess the associations between genetic risk factors (such as the mutational status of the IGHV gene and polymorphisms of the IL-10 and TNF-α genes) and CLL risk, prognosis, and overall survival. Another goal of this study was to evaluate the multivariate effect of the combination of multiple genetic risk factors (mutational status of the IGHV gene, somatic mutations, DNA CNVs, and cytokine SNPs) on the clinical characteristics and survival of patients. A total of 125 CLL patients and 239 healthy controls were included for comparative SNP analysis. IL-10 (rs1800896 and rs1800872) and TNF-α (rs361525 and rs1800750) SNPs and haplotypes were not associated with CLL risk. The absence of hypermutation in the IGHV gene was shown to be of important prognostic value, being associated with short OS. Further individual risk factors for short OS were an age above 65 years at diagnosis and the presence of somatic mutations and/or CNVs. In our multivariable analysis, the presence of somatic mutations and the IL-10 rs1800872 variant allele, and the association of CNVs with the IL-10 rs1800896 variant allele, were identified as risk factors for short OS. Moreover, the OS in unmutated IGHV patients was additionally affected (decreased) by the presence of CNVs and/or somatic mutations. Similarly, IL-10 rs1800896 modulated the OS in unmutated IGHV patients with CNVs.
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Affiliation(s)
- Beata Balla
- Department of Medical Genetics, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Targu Mures, 540139 Targu Mures, Romania; (B.B.); (C.B.)
- Center for Advanced Medical and Pharmaceutical Research, Genetics Laboratory, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Targu Mures, 540139 Targu Mures, Romania
- Medical Genetics Laboratory, Emergency County Hospital of Targu Mures, 540136 Targu Mures, Romania
| | - Florin Tripon
- Department of Medical Genetics, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Targu Mures, 540139 Targu Mures, Romania; (B.B.); (C.B.)
- Center for Advanced Medical and Pharmaceutical Research, Genetics Laboratory, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Targu Mures, 540139 Targu Mures, Romania
- Medical Genetics Laboratory, Emergency County Hospital of Targu Mures, 540136 Targu Mures, Romania
| | - Erzsebet Lazar
- Department of Internal Medicine, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Targu Mures, 540139 Targu Mures, Romania;
| | - Claudia Bănescu
- Department of Medical Genetics, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Targu Mures, 540139 Targu Mures, Romania; (B.B.); (C.B.)
- Center for Advanced Medical and Pharmaceutical Research, Genetics Laboratory, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Targu Mures, 540139 Targu Mures, Romania
- Medical Genetics Laboratory, Emergency County Hospital of Targu Mures, 540136 Targu Mures, Romania
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de Groen PC. A new, all-encompassing aetiology of type 1 diabetes. Immunology 2024; 171:77-91. [PMID: 37772700 DOI: 10.1111/imm.13700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 09/10/2023] [Indexed: 09/30/2023] Open
Abstract
The aetiology of type 1 diabetes (T1D) is considered multifactorial with the contribution of the MHC on chromosome 6 being most important. Multiple factors also contribute to the aetiology of colorectal neoplasia, but the final event causing the change from normal mucosa to polyp and from polyp to cancer is due to a single somatic mutation event. Repeated formation of colorectal neoplasia within an at-risk population results in a predictable, tapering, exponential neoplasia distribution. Critical mutations driving colorectal neoplasia formation occur in mutation-prone DNA. These observations led to three hypotheses related to T1D. First, a single somatic mutation within the MHC of antigen presenting cells results in a change in phenotype from normal to T1D. Second, the distribution of additional autoimmune diseases (AAIDs) among persons with T1D adheres to a predictable, tapering, exponential distribution. And third, critical mutations driving development of T1D occur in mutation-prone DNA. To address the hypotheses in an orderly fashion, a new analytical method called genome-wide aetiology analysis (GWEA) consisting of nine steps is presented. All data required for GWEA of T1D are obtained from peer-reviewed publications or publicly available genome and proteome databases. Critical GWEA steps include AAID distribution among persons with T1D, analysis of at-risk HLA loci for mutation-prone DNA, determination of the role of non-MHC genes on GWAS, and verification of human data by cell culture or animal experiments. GWEA results show that distribution of AAID among persons with T1D adheres to a predictable, tapering, exponential distribution. A single, critical, somatic mutation within the epitope-binding groove of at-risk HLA loci alters HLA-insulin-peptide-T-cell-receptor (TCR) complex binding affinity and creates a new pathway that leads to loss of self-tolerance. The at-risk HLA loci, in particular binding pockets P1, P4 and P9, are encoded by mutation-prone DNA: GC-rich DNA sequence and somatic hypermutation hotspots. All other genes on GWAS can but do not have to amplify the new autoimmune pathway by facilitating DNA mutations, changing peptide binding affinity, reducing signal inhibition or augmenting signal intensity. Animal experiments agree with human studies. In conclusion, T1D is caused by a somatic mutation within the epitope-binding groove of an at-risk HLA gene that affects HLA-insulin-peptide-TCR complex binding affinity and initiates an autoimmune pathway. The nature of the peptide that binds to a mutated epitope-binding groove of an at-risk HLA gene determines the type of autoimmune disease that develops, that is, one at-risk HLA locus, multiple autoimmune diseases. Thus, T1D and AAIDs, and therefore common autoimmune diseases, share a similar somatic mutation-based aetiology.
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Affiliation(s)
- Piet C de Groen
- Division of Gastroenterology, Hepatology & Nutrition, University of Minnesota, Minneapolis, Minnesota, USA
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Zhang C, Bzikadze AV, Safonova Y, Mirarab S. A scalable model for simulating multi-round antibody evolution and benchmarking of clonal tree reconstruction methods. Front Immunol 2022; 13:1014439. [PMID: 36618367 PMCID: PMC9815712 DOI: 10.3389/fimmu.2022.1014439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 10/26/2022] [Indexed: 12/12/2022] Open
Abstract
Affinity maturation (AM) of B cells through somatic hypermutations (SHMs) enables the immune system to evolve to recognize diverse pathogens. The accumulation of SHMs leads to the formation of clonal lineages of antibody-secreting b cells that have evolved from a common naïve B cell. Advances in high-throughput sequencing have enabled deep scans of B cell receptor repertoires, paving the way for reconstructing clonal trees. However, it is not clear if clonal trees, which capture microevolutionary time scales, can be reconstructed using traditional phylogenetic reconstruction methods with adequate accuracy. In fact, several clonal tree reconstruction methods have been developed to fix supposed shortcomings of phylogenetic methods. Nevertheless, no consensus has been reached regarding the relative accuracy of these methods, partially because evaluation is challenging. Benchmarking the performance of existing methods and developing better methods would both benefit from realistic models of clonal lineage evolution specifically designed for emulating B cell evolution. In this paper, we propose a model for modeling B cell clonal lineage evolution and use this model to benchmark several existing clonal tree reconstruction methods. Our model, designed to be extensible, has several features: by evolving the clonal tree and sequences simultaneously, it allows modeling selective pressure due to changes in affinity binding; it enables scalable simulations of large numbers of cells; it enables several rounds of infection by an evolving pathogen; and, it models building of memory. In addition, we also suggest a set of metrics for comparing clonal trees and measuring their properties. Our results show that while maximum likelihood phylogenetic reconstruction methods can fail to capture key features of clonal tree expansion if applied naively, a simple post-processing of their results, where short branches are contracted, leads to inferences that are better than alternative methods.
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Affiliation(s)
- Chao Zhang
- Bioinformatics and Systems Biology, University of California, San Diego, San Diego, CA, United States
| | - Andrey V. Bzikadze
- Bioinformatics and Systems Biology, University of California, San Diego, San Diego, CA, United States
| | - Yana Safonova
- Computer Science and Engineering Department, University of California, San Diego, San Diego, CA, United States
| | - Siavash Mirarab
- Electrical and Computer Engineering Department, University of California, San Diego, San Diego, CA, United States,*Correspondence: Siavash Mirarab,
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van Bladel DAG, Stevens WBC, van den Brand M, Kroeze LI, Groenen PJTA, van Krieken JHJM, Hebeda KM, Scheijen B. Novel Approaches in Molecular Characterization of Classical Hodgkin Lymphoma. Cancers (Basel) 2022; 14:cancers14133222. [PMID: 35805000 PMCID: PMC9264882 DOI: 10.3390/cancers14133222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary The unique tumor composition of classical Hodgkin lymphoma (cHL), with only a small fraction of malignant Hodgkin and Reed–Sternberg cells within the tumor tissue, has created many challenges to characterize the genetic alterations that drive this lymphoid malignancy. Major advances in sequencing technologies and detailed analysis of circulating tumor DNA in blood samples of patients have provided important contributions to enhance our understanding of the pathogenesis of cHL. In this review, we provide an overview of the recent advances in genotyping the clonal and mutational landscape of cHL. In addition, we discuss different next-generation sequencing applications to characterize tumor tissue and cell-free DNA, which are now available to improve the diagnosis of cHL, and to monitor therapeutic response or disease progression during treatment and follow up of cHL patients. Abstract Classical Hodgkin lymphoma (cHL) represents a B-cell lymphoproliferative disease characterized by clonal immunoglobulin gene rearrangements and recurrent genomic aberrations in the Hodgkin Reed–Sternberg cells in a reactive inflammatory background. Several methods are available for the molecular analysis of cHL on both tissue and cell-free DNA isolated from blood, which can provide detailed information regarding the clonal composition and genetic alterations that drive lymphoma pathogenesis. Clonality testing involving the detection of immunoglobulin and T cell receptor gene rearrangements, together with mutation analysis, represent valuable tools for cHL diagnostics, especially for patients with an atypical histological or clinical presentation reminiscent of a reactive lesion or another lymphoma subtype. In addition, clonality assessment may establish the clonal relationship of composite or subsequent lymphoma presentations within one patient. During the last few decades, more insight has been obtained on the molecular mechanisms that drive cHL development, including recurrently affected signaling pathways (e.g., NF-κB and JAK/STAT) and immune evasion. We provide an overview of the different approaches to characterize the molecular composition of cHL, and the implementation of these next-generation sequencing-based techniques in research and diagnostic settings.
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Affiliation(s)
- Diede A. G. van Bladel
- Radboud University Medical Center, Department of Pathology, 6525 GA Nijmegen, The Netherlands; (D.A.G.v.B.); (M.v.d.B.); (L.I.K.); (P.J.T.A.G.); (J.H.J.M.v.K.); (K.M.H.)
- Radboud Institute for Molecular Life Sciences, 6525 GA Nijmegen, The Netherlands
| | - Wendy B. C. Stevens
- Radboud University Medical Center, Department of Hematology, 6525 GA Nijmegen, The Netherlands;
| | - Michiel van den Brand
- Radboud University Medical Center, Department of Pathology, 6525 GA Nijmegen, The Netherlands; (D.A.G.v.B.); (M.v.d.B.); (L.I.K.); (P.J.T.A.G.); (J.H.J.M.v.K.); (K.M.H.)
- Pathology-DNA, Rijnstate Hospital, 6815 AD Arnhem, The Netherlands
| | - Leonie I. Kroeze
- Radboud University Medical Center, Department of Pathology, 6525 GA Nijmegen, The Netherlands; (D.A.G.v.B.); (M.v.d.B.); (L.I.K.); (P.J.T.A.G.); (J.H.J.M.v.K.); (K.M.H.)
| | - Patricia J. T. A. Groenen
- Radboud University Medical Center, Department of Pathology, 6525 GA Nijmegen, The Netherlands; (D.A.G.v.B.); (M.v.d.B.); (L.I.K.); (P.J.T.A.G.); (J.H.J.M.v.K.); (K.M.H.)
| | - J. Han J. M. van Krieken
- Radboud University Medical Center, Department of Pathology, 6525 GA Nijmegen, The Netherlands; (D.A.G.v.B.); (M.v.d.B.); (L.I.K.); (P.J.T.A.G.); (J.H.J.M.v.K.); (K.M.H.)
| | - Konnie M. Hebeda
- Radboud University Medical Center, Department of Pathology, 6525 GA Nijmegen, The Netherlands; (D.A.G.v.B.); (M.v.d.B.); (L.I.K.); (P.J.T.A.G.); (J.H.J.M.v.K.); (K.M.H.)
| | - Blanca Scheijen
- Radboud University Medical Center, Department of Pathology, 6525 GA Nijmegen, The Netherlands; (D.A.G.v.B.); (M.v.d.B.); (L.I.K.); (P.J.T.A.G.); (J.H.J.M.v.K.); (K.M.H.)
- Radboud Institute for Molecular Life Sciences, 6525 GA Nijmegen, The Netherlands
- Correspondence:
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Zhang Z, Chang WY, Wang K, Yang Y, Wang X, Yao C, Wu T, Wang L, Wang T. Interpreting the B-cell receptor repertoire with single-cell gene expression using Benisse. NAT MACH INTELL 2022. [DOI: 10.1038/s42256-022-00492-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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7
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van Bladel DAG, van der Last-Kempkes JLM, Scheijen B, Groenen PJTA. Next-Generation Sequencing-Based Clonality Detection of Immunoglobulin Gene Rearrangements in B-Cell Lymphoma. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2453:7-42. [PMID: 35622318 DOI: 10.1007/978-1-0716-2115-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Immunoglobulin (IG) clonality assessment is a widely used supplementary test for the diagnosis of suspected lymphoid malignancies. The specific rearrangements of the immunoglobulin (IG) heavy and light chain genes act as a unique hallmark of a B-cell lymphoma, a feature that is used in clonality assessment. The widely used BIOMED-2/EuroClonality IG clonality assay, visualized by GeneScanning or heteroduplex analysis, has an unprecedented high detection rate because of the complementarity of this approach. However, the BIOMED-2/EuroClonality clonality assays have been developed for the assessment of specimens with optimal DNA quality. Further improvements for the assessment of samples with suboptimal DNA quality, such as from formalin-fixed paraffin-embedded (FFPE) specimens or specimens with a limited tumor burden, are required. The EuroClonality-NGS Working Group recently developed a next-generation sequencing (NGS)-based clonality assay for the detection of the IG heavy and kappa light chain rearrangements, using the same complementary approach as in the conventional assay. By employing next-generation sequencing, both the sensitivity and specificity of the clonality assay have increased, which not only is very useful for diagnostic clonality testing but also allows robust comparison of clonality patterns in a patient with multiple lymphoma's that have suboptimal DNA quality. Here, we describe the protocols for IG-NGS clonality assessment that are compatible for Ion Torrent and Illumina sequencing platforms including pre-analytical DNA isolation, the analytical phase, and the post-analytical data analysis.
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Affiliation(s)
- Diede A G van Bladel
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Blanca Scheijen
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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A Trade-off Between Thermostability and Binding Affinity of Anti-(4-hydroxy-3-nitrophenyl)Acetyl Antibodies During the Course of Affinity Maturation. Protein J 2022; 41:293-303. [DOI: 10.1007/s10930-022-10053-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2022] [Indexed: 10/18/2022]
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9
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Sepúlveda-Yáñez JH, Alvarez Saravia D, Pilzecker B, van Schouwenburg PA, van den Burg M, Veelken H, Navarrete MA, Jacobs H, Koning MT. Tandem Substitutions in Somatic Hypermutation. Front Immunol 2022; 12:807015. [PMID: 35069591 PMCID: PMC8781386 DOI: 10.3389/fimmu.2021.807015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/16/2021] [Indexed: 11/13/2022] Open
Abstract
Upon antigen recognition, activation-induced cytosine deaminase initiates affinity maturation of the B-cell receptor by somatic hypermutation (SHM) through error-prone DNA repair pathways. SHM typically creates single nucleotide substitutions, but tandem substitutions may also occur. We investigated incidence and sequence context of tandem substitutions by massive parallel sequencing of V(D)J repertoires in healthy human donors. Mutation patterns were congruent with SHM-derived single nucleotide mutations, delineating initiation of the tandem substitution by AID. Tandem substitutions comprised 5,7% of AID-induced mutations. The majority of tandem substitutions represents single nucleotide juxtalocations of directly adjacent sequences. These observations were confirmed in an independent cohort of healthy donors. We propose a model where tandem substitutions are predominantly generated by translesion synthesis across an apyramidinic site that is typically created by UNG. During replication, apyrimidinic sites transiently adapt an extruded configuration, causing skipping of the extruded base. Consequent strand decontraction leads to the juxtalocation, after which exonucleases repair the apyramidinic site and any directly adjacent mismatched base pairs. The mismatch repair pathway appears to account for the remainder of tandem substitutions. Tandem substitutions may enhance affinity maturation and expedite the adaptive immune response by overcoming amino acid codon degeneracies or mutating two adjacent amino acid residues simultaneously.
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Affiliation(s)
- Julieta H Sepúlveda-Yáñez
- Department of Hematology, Leiden University Medical Center, Leiden, Netherlands
- School of Medicine, University of Magallanes, Punta Arenas, Chile
| | | | - Bas Pilzecker
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Nijmegen, Netherlands
- Division of Tumor Biology and Immunology, Netherlands Cancer Institute, Amsterdam, Netherlands
| | | | - Mirjam van den Burg
- Department of Pediatrics, Leiden University Medical Center, Leiden, Netherlands
| | - Hendrik Veelken
- Department of Hematology, Leiden University Medical Center, Leiden, Netherlands
| | | | - Heinz Jacobs
- Division of Tumor Biology and Immunology, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Marvyn T Koning
- Department of Hematology, Leiden University Medical Center, Leiden, Netherlands
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Sakhtemani R, Perera MLW, Hübschmann D, Siebert R, Lawrence M, Bhagwat A. OUP accepted manuscript. Nucleic Acids Res 2022; 50:5145-5157. [PMID: 35524550 PMCID: PMC9122604 DOI: 10.1093/nar/gkac296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/08/2022] [Accepted: 04/29/2022] [Indexed: 12/04/2022] Open
Abstract
Activation-induced deaminase (AID) is a DNA-cytosine deaminase that mediates maturation of antibodies through somatic hypermutation and class-switch recombination. While it causes mutations in immunoglobulin heavy and light chain genes and strand breaks in the switch regions of the immunoglobulin heavy chain gene, it largely avoids causing such damage in the rest of the genome. To help understand targeting by human AID, we expressed it in repair-deficient Escherichia coli and mapped the created uracils in the genomic DNA using uracil pull-down and sequencing, UPD-seq. We found that both AID and the human APOBEC3A preferentially target tRNA genes and transcription start sites, but do not show preference for highly transcribed genes. Unlike A3A, AID did not show a strong replicative strand bias or a preference for hairpin loops. Overlapping uracilation peaks between these enzymes contained binding sites for a protein, FIS, that helps create topological domains in the E. coli genome. To confirm whether these findings were relevant to B cells, we examined mutations from lymphoma and leukemia genomes within AID-preferred sequences. These mutations also lacked replicative strand bias or a hairpin loop preference. We propose here a model for how AID avoids causing mutations in the single-stranded DNA found within replication forks.
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Affiliation(s)
- Ramin Sakhtemani
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA
| | | | - Daniel Hübschmann
- Molecular Precision Oncology Program, National Center for Tumor Diseases, Heidelberg and German Cancer Research Center, Heidelberg, Germany
- Heidelberg Institute for Stem cell Technology and Experimental Medicine, Heidelberg, Germany
- German Cancer Consortium, Heidelberg, Germany
| | - Reiner Siebert
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, Ulm, Germany
| | - Michael S Lawrence
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA
| | - Ashok S Bhagwat
- To whom correspondence should be addressed. Tel: +1 734 425 1749; Fax: +1 313 577 8822, 443;
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11
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Sikora KA, Wells KV, Bolek EC, Jones AI, Grayson PC. Somatic Mutations in Rheumatologic Diseases: VEXAS Syndrome and Beyond. Rheumatology (Oxford) 2021; 61:3149-3160. [PMID: 34888629 DOI: 10.1093/rheumatology/keab868] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 10/27/2021] [Accepted: 11/06/2021] [Indexed: 11/15/2022] Open
Abstract
Discovery of the VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome demonstrates that somatic mutations in hematologic precursor cells can cause adult-onset, complex inflammatory disease. Unlike germline mutations, somatic mutations occur throughout the lifespan, are restricted to specific tissue types, and may play a causal role in non-heritable rheumatologic diseases, especially conditions that start in later life. Improvements in sequencing technology have enabled researchers and clinicians to detect somatic mutations in various tissue types, especially blood. Understanding the relationships between cell-specific acquired mutations and inflammation is likely to yield key insights into causal factors that underlie many rheumatologic diseases. The objective of this review is to detail how somatic mutations are likely to be relevant to clinicians who care for patients with rheumatologic diseases, with particular focus on the pathogenetic mechanisms of the VEXAS syndrome.
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Affiliation(s)
- Keith A Sikora
- National Institutes of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kristina V Wells
- National Institutes of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ertugrul Cagri Bolek
- National Institutes of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
- Division of Rheumatology, Department of Internal Medicine, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Adrianna I Jones
- National Institutes of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Peter C Grayson
- National Institutes of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
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12
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Khatri I, Diks AM, van den Akker EB, Oosten LEM, Zwaginga JJ, Reinders MJT, van Dongen JJM, Berkowska MA. Longitudinal Dynamics of Human B-Cell Response at the Single-Cell Level in Response to Tdap Vaccination. Vaccines (Basel) 2021; 9:1352. [PMID: 34835283 PMCID: PMC8617659 DOI: 10.3390/vaccines9111352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/08/2021] [Accepted: 11/13/2021] [Indexed: 01/28/2023] Open
Abstract
To mount an adequate immune response against pathogens, stepwise mutation and selection processes are crucial functions of the adaptive immune system. To better characterize a successful vaccination response, we performed longitudinal (days 0, 5, 7, 10, and 14 after Boostrix vaccination) analysis of the single-cell transcriptome as well as the B-cell receptor (BCR) repertoire (scBCR-rep) in plasma cells of an immunized donor and compared it with baseline B-cell characteristics as well as flow cytometry findings. Based on the flow cytometry knowledge and literature findings, we discriminated individual B-cell subsets in the transcriptomics data and traced over-time maturation of plasmablasts/plasma cells (PB/PCs) and identified the pathways associated with the plasma cell maturation. We observed that the repertoire in PB/PCs differed from the baseline B-cell repertoire e.g., regarding expansion of unique clones in post-vaccination visits, high usage of IGHG1 in expanded clones, increased class-switching events post-vaccination represented by clonotypes spanning multiple IGHC classes and positive selection of CDR3 sequences over time. Importantly, the Variable gene family-based clustering of BCRs represented a similar measure as the gene-based clustering, but certainly improved the clustering of BCRs, as BCRs from duplicated Variable gene families could be clustered together. Finally, we developed a query tool to dissect the immune response to the components of the Boostrix vaccine. Using this tool, we could identify the BCRs related to anti-tetanus and anti-pertussis toxoid BCRs. Collectively, we developed a bioinformatic workflow which allows description of the key features of an ongoing (longitudinal) immune response, such as activation of PB/PCs, Ig class switching, somatic hypermutation, and clonal expansion, all of which are hallmarks of antigen exposure, followed by mutation & selection processes.
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Affiliation(s)
- Indu Khatri
- Department of Immunology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (I.K.); (A.M.D.); (M.A.B.)
- Leiden Computational Biology Center, Leiden University Medical Center, 2333 ZC Leiden, The Netherlands; (E.B.v.d.A.); (M.J.T.R.)
| | - Annieck M. Diks
- Department of Immunology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (I.K.); (A.M.D.); (M.A.B.)
| | - Erik B. van den Akker
- Leiden Computational Biology Center, Leiden University Medical Center, 2333 ZC Leiden, The Netherlands; (E.B.v.d.A.); (M.J.T.R.)
- Department of Molecular Epidemiology, Leiden University Medical Center, 2333 ZC Leiden, The Netherlands
| | - Liesbeth E. M. Oosten
- Department of Hematology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (L.E.M.O.); (J.J.Z.)
| | - Jaap Jan Zwaginga
- Department of Hematology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (L.E.M.O.); (J.J.Z.)
| | - Marcel J. T. Reinders
- Leiden Computational Biology Center, Leiden University Medical Center, 2333 ZC Leiden, The Netherlands; (E.B.v.d.A.); (M.J.T.R.)
- Delft Bioinformatics Lab, Delft University of Technology, 2628 CD Delft, The Netherlands
| | - Jacques J. M. van Dongen
- Department of Immunology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (I.K.); (A.M.D.); (M.A.B.)
| | - Magdalena A. Berkowska
- Department of Immunology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (I.K.); (A.M.D.); (M.A.B.)
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13
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Immune Gene Rearrangements: Unique Signatures for Tracing Physiological Lymphocytes and Leukemic Cells. Genes (Basel) 2021; 12:genes12070979. [PMID: 34198966 PMCID: PMC8329920 DOI: 10.3390/genes12070979] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 06/25/2021] [Indexed: 02/07/2023] Open
Abstract
The tremendous diversity of the human immune repertoire, fundamental for the defense against highly heterogeneous pathogens, is based on the ingenious mechanism of immune gene rearrangements. Rearranged immune genes encoding the immunoglobulins and T-cell receptors and thus determining each lymphocyte's antigen specificity are very valuable molecular markers for tracing malignant or physiological lymphocytes. One of their most significant applications is tracking residual leukemic cells in patients with lymphoid malignancies. This so called 'minimal residual disease' (MRD) has been shown to be the most important prognostic factor across various leukemia subtypes and has therefore been given enormous attention. Despite the current rapid development of the molecular methods, the classical real-time PCR based approach is still being regarded as the standard method for molecular MRD detection due to the cumbersome standardization of the novel approaches currently in progress within the EuroMRD and EuroClonality NGS Consortia. Each of the molecular methods, however, poses certain benefits and it is therefore expectable that none of the methods for MRD detection will clearly prevail over the others in the near future.
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14
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Leong TL, Bryant VL. B cells in lung cancer-not just a bystander cell: a literature review. Transl Lung Cancer Res 2021; 10:2830-2841. [PMID: 34295681 PMCID: PMC8264333 DOI: 10.21037/tlcr-20-788] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 01/19/2021] [Indexed: 01/08/2023]
Abstract
Metastatic lung cancer represents a significant global issue where it is responsible for the most cancer diagnoses and deaths worldwide. Treatment for advanced lung cancer has undergone a series of paradigm shifts from chemotherapy to targeted molecular agents to the most recent immunotherapy strategies. The most successful of the latter involves antibodies that block inhibitory receptors on tumor infiltrating T cells, thereby enhancing T cell activity against tumor cells. However, only a subset of patients demonstrate durable responses to these drugs and treatment resistance is common. Emerging evidence suggests that a critical role exists for B cells as more than a bystander immune cell in the tumor microenvironment (TME). However, this role is likely context-specific where B cells comprise distinct subtypes with unique effector functions that may result in anti- or pro-tumor effects. As such, the balance between various B cell subtypes affects the net B cell impact upon tumor immunity. To date, the factors needed to polarize B cell function toward anti-tumor activity are unclear. Understanding B cell biology in the lung cancer setting will help redefine and refine treatment strategies to augment anti-tumor immunity. This article presents a review of the literature describing the current knowledge of the development and function of B cells, and explores their role in lung cancer and potential as an immunotherapeutic strategy and as a predictive marker for response to immune checkpoint blockade.
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Affiliation(s)
- Tracy L Leong
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Respiratory and Sleep Medicine, Austin Health, Heidelberg, Victoria, Australia
- Institute of Breathing and Sleep, Heidelberg, Victoria, Australia
- Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Vanessa L Bryant
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
- Department of Allergy and Clinical Immunology, Royal Melbourne Hospital, Parkville, Victoria, Australia
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15
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Gupta SK, Viswanatha DS, Patel KP. Evaluation of Somatic Hypermutation Status in Chronic Lymphocytic Leukemia (CLL) in the Era of Next Generation Sequencing. Front Cell Dev Biol 2020; 8:357. [PMID: 32509784 PMCID: PMC7248390 DOI: 10.3389/fcell.2020.00357] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/21/2020] [Indexed: 01/22/2023] Open
Abstract
Somatic hypermutation (SHM) status provides an important prognostic indicator for chronic lymphocytic leukemia (CLL), a very common type of mature B-cell leukemia. Owing to the adverse prognosis associated with an unmutated immunoglobulin heavy chain variable (IGHV) status, SHM testing is performed as a standard of care in CLL. Conventionally, SHM testing has been performed using labor intensive and primarily analog Sanger sequencing method following PCR amplification of the clonal immunoglobulin heavy chain gene rearrangements in CLL cells. In comparison, recent availability of next generation sequencing (NGS) allows more versatile detection and direct identification of clonal immunoglobulin gene rearrangements in neoplastic B-cell populations. The ability to identify specific clonal IGHV signature(s) in both baseline (diagnostic) and post-treatment settings enables unique clinical applications of NGS such as determination of SHM status, minimal residual disease (MRD) monitoring, clonal heterogeneity and B cell receptor IG stereotypy. We provide a review of current practices and recommendations for SHM determination using NGS including examples of difficult cases.
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Affiliation(s)
- Sanjeev Kumar Gupta
- Laboratory Oncology Unit, Dr. B.R.A IRCH, All India Institute of Medical Sciences, New Delhi, New Delhi, India
| | | | - Keyur P. Patel
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
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16
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Chiu ML, Goulet DR, Teplyakov A, Gilliland GL. Antibody Structure and Function: The Basis for Engineering Therapeutics. Antibodies (Basel) 2019; 8:antib8040055. [PMID: 31816964 PMCID: PMC6963682 DOI: 10.3390/antib8040055] [Citation(s) in RCA: 207] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 11/25/2019] [Accepted: 11/28/2019] [Indexed: 12/11/2022] Open
Abstract
Antibodies and antibody-derived macromolecules have established themselves as the mainstay in protein-based therapeutic molecules (biologics). Our knowledge of the structure–function relationships of antibodies provides a platform for protein engineering that has been exploited to generate a wide range of biologics for a host of therapeutic indications. In this review, our basic understanding of the antibody structure is described along with how that knowledge has leveraged the engineering of antibody and antibody-related therapeutics having the appropriate antigen affinity, effector function, and biophysical properties. The platforms examined include the development of antibodies, antibody fragments, bispecific antibody, and antibody fusion products, whose efficacy and manufacturability can be improved via humanization, affinity modulation, and stability enhancement. We also review the design and selection of binding arms, and avidity modulation. Different strategies of preparing bispecific and multispecific molecules for an array of therapeutic applications are included.
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Affiliation(s)
- Mark L. Chiu
- Drug Product Development Science, Janssen Research & Development, LLC, Malvern, PA 19355, USA
- Correspondence:
| | - Dennis R. Goulet
- Department of Medicinal Chemistry, University of Washington, P.O. Box 357610, Seattle, WA 98195-7610, USA;
| | - Alexey Teplyakov
- Biologics Research, Janssen Research & Development, LLC, Spring House, PA 19477, USA; (A.T.); (G.L.G.)
| | - Gary L. Gilliland
- Biologics Research, Janssen Research & Development, LLC, Spring House, PA 19477, USA; (A.T.); (G.L.G.)
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17
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Costello R, Cantillo JF, Kenter AL. Chicken MBD4 Regulates Immunoglobulin Diversification by Somatic Hypermutation. Front Immunol 2019; 10:2540. [PMID: 31736964 PMCID: PMC6838969 DOI: 10.3389/fimmu.2019.02540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 10/14/2019] [Indexed: 01/21/2023] Open
Abstract
Immunoglobulin (Ig) diversification occurs via somatic hypermutation (SHM) and class switch recombination (CSR), and is initiated by activation-induced deaminase (AID), which converts cytosine to uracil. Variable (V) region genes undergo SHM to create amino acid substitutions that produce antibodies with higher affinity for antigen. The conversion of cytosine to uracil in DNA promotes mutagenesis. Two distinct DNA repair mechanisms regulate uracil processing in Ig genes. The first involves base removal by the uracil DNA glycosylase (UNG), and the second detects uracil via the mismatch repair (MMR) complex. Methyl binding domain protein 4 (MBD4) is a uracil glycosylase and an intriguing candidate for involvement in somatic hypermutation because of its interaction with the MMR MutL homolog 1 (MLH1). We found that the DNA uracil glycosylase domain of MBD4 is highly conserved among mammals, birds, shark, and insects. Conservation of the human and chicken MBD4 uracil glycosylase domain structure is striking. Here we examined the function of MBD4 in chicken DT40 B cells which undergo constitutive SHM. We constructed structural variants of MBD4 DT40 cells using CRISPR/Cas9 genome editing. Disruption of the MBD4 uracil glycosylase catalytic region increased SHM frequency in IgM loss assays. We propose that MBD4 plays a role in SHM.
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Affiliation(s)
- Ryan Costello
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, United States
| | - Jose F Cantillo
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, United States
| | - Amy L Kenter
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, United States
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18
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Pilzecker B, Jacobs H. Mutating for Good: DNA Damage Responses During Somatic Hypermutation. Front Immunol 2019; 10:438. [PMID: 30915081 PMCID: PMC6423074 DOI: 10.3389/fimmu.2019.00438] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 02/19/2019] [Indexed: 11/13/2022] Open
Abstract
Somatic hypermutation (SHM) of immunoglobulin (Ig) genes plays a key role in antibody mediated immunity. SHM in B cells provides the molecular basis for affinity maturation of antibodies. In this way SHM is key in optimizing antibody dependent immune responses. SHM is initiated by targeting the Activation-Induced Cytidine Deaminase (AID) to rearranged V(D)J and switch regions of Ig genes. The mutation rate of this programmed mutagenesis is ~10-3 base pairs per generation, a million-fold higher than the non-AID targeted genome of B cells. AID is a processive enzyme that binds single-stranded DNA and deaminates cytosines in DNA. Cytosine deamination generates highly mutagenic deoxy-uracil (U) in the DNA of both strands of the Ig loci. Mutagenic processing of the U by the DNA damage response generates the entire spectrum of base substitutions characterizing SHM at and around the initial U lesion. Starting from the U as a primary lesion, currently five mutagenic DNA damage response pathways have been identified in generating a well-defined SHM spectrum of C/G transitions, C/G transversions, and A/T mutations around this initial lesion. These pathways include (1) replication opposite template U generates transitions at C/G, (2) UNG2-dependent translesion synthesis (TLS) generates transversions at C/G, (3) a hybrid pathway comprising non-canonical mismatch repair (ncMMR) and UNG2-dependent TLS generates transversions at C/G, (4) ncMMR generates mutations at A/T, and (5) UNG2- and PCNA Ubiquitination (PCNA-Ub)-dependent mutations at A/T. Furthermore, specific strand-biases of SHM spectra arise as a consequence of a biased AID targeting, ncMMR, and anti-mutagenic repriming. Here, we review mammalian SHM with special focus on the mutagenic DNA damage response pathways involved in processing AID induced Us, the origin of characteristic strand biases, and relevance of the cell cycle.
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Affiliation(s)
- Bas Pilzecker
- Division of Tumor Biology & Immunology, The Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Heinz Jacobs
- Division of Tumor Biology & Immunology, The Netherlands Cancer Institute, Amsterdam, Netherlands
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19
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Lim SSY, Chua KH, Nölke G, Spiegel H, Goh WL, Chow SC, Kee BP, Fischer R, Schillberg S, Othman RY. Plant-derived chimeric antibodies inhibit the invasion of human fibroblasts by Toxoplasma gondii. PeerJ 2018; 6:e5780. [PMID: 30581655 PMCID: PMC6294049 DOI: 10.7717/peerj.5780] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/17/2018] [Indexed: 11/25/2022] Open
Abstract
The parasite Toxoplasma gondii causes an opportunistic infection, that is, particularly severe in immunocompromised patients, infants, and neonates. Current antiparasitic drugs are teratogenic and cause hypersensitivity-based toxic side effects especially during prolonged treatment. Furthermore, the recent emergence of drug-resistant toxoplasmosis has reduced the therapeutic impact of such drugs. In an effort to develop recombinant antibodies as a therapeutic alternative, a panel of affinity-matured, T. gondii tachyzoite-specific single-chain variable fragment (scFv) antibodies was selected by phage display and bioinformatic analysis. Further affinity optimization was attempted by introducing point mutations at hotspots within light chain complementarity-determining region 2. This strategy yielded four mutated scFv sequences and a parental scFv that were used to produce five mouse-human chimeric IgGs in Nicotiana benthamiana plants, with yields of 33-72 mg/kg of plant tissue. Immunological analysis confirmed the specific binding of these plant-derived antibodies to T. gondii tachyzoites, and in vitro efficacy was demonstrated by their ability to inhibit the invasion of human fibroblasts and impair parasite infectivity. These novel recombinant antibodies could therefore be suitable for the development of plant-derived immunotherapeutic interventions against toxoplasmosis.
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Affiliation(s)
| | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Greta Nölke
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Holger Spiegel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Wai Leong Goh
- School of Science, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - Sek Chuen Chow
- School of Science, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - Boon Pin Kee
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Rainer Fischer
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Stefan Schillberg
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Rofina Yasmin Othman
- Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia
- Centre for Research in Biotechnology for Agriculture, University of Malaya, Kuala Lumpur, Malaysia
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20
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Giesecke C, Meyer T, Durek P, Maul J, Preiß J, Jacobs JFM, Thiel A, Radbruch A, Ullrich R, Dörner T. Simultaneous Presence of Non- and Highly Mutated Keyhole Limpet Hemocyanin (KLH)-Specific Plasmablasts Early after Primary KLH Immunization Suggests Cross-Reactive Memory B Cell Activation. THE JOURNAL OF IMMUNOLOGY 2018; 200:3981-3992. [DOI: 10.4049/jimmunol.1701728] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 04/13/2018] [Indexed: 12/25/2022]
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21
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Ovchinnikov V, Louveau JE, Barton JP, Karplus M, Chakraborty AK. Role of framework mutations and antibody flexibility in the evolution of broadly neutralizing antibodies. eLife 2018; 7:33038. [PMID: 29442996 PMCID: PMC5828663 DOI: 10.7554/elife.33038] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 02/13/2018] [Indexed: 01/13/2023] Open
Abstract
Eliciting antibodies that are cross reactive with surface proteins of diverse strains of highly mutable pathogens (e.g., HIV, influenza) could be key for developing effective universal vaccines. Mutations in the framework regions of such broadly neutralizing antibodies (bnAbs) have been reported to play a role in determining their properties. We used molecular dynamics simulations and models of affinity maturation to study specific bnAbs against HIV. Our results suggest that there are different classes of evolutionary lineages for the bnAbs. If germline B cells that initiate affinity maturation have high affinity for the conserved residues of the targeted epitope, framework mutations increase antibody rigidity as affinity maturation progresses to evolve bnAbs. If the germline B cells exhibit weak/moderate affinity for conserved residues, an initial increase in flexibility via framework mutations may be required for the evolution of bnAbs. Subsequent mutations that increase rigidity result in highly potent bnAbs. Implications of our results for immunogen design are discussed.
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Affiliation(s)
- Victor Ovchinnikov
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States
| | - Joy E Louveau
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, United States
| | - John P Barton
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, United States.,Department of Physics, Massachusetts Institute of Technology, Cambridge, United States.,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, United States.,Ragon Institute of MGH, MIT and Harvard, Cambridge, United States
| | - Martin Karplus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States.,Laboratoire de Chimie Biophysique, ISIS, Universite de Strasbourg, Strasbourg, France
| | - Arup K Chakraborty
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, United States.,Department of Physics, Massachusetts Institute of Technology, Cambridge, United States.,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, United States.,Ragon Institute of MGH, MIT and Harvard, Cambridge, United States.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States.,Department of Chemistry, Massachusetts Institute of Technology, Cambridge, United States
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22
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Choudhary M, Tamrakar A, Singh AK, Jain M, Jaiswal A, Kodgire P. AID Biology: A pathological and clinical perspective. Int Rev Immunol 2017; 37:37-56. [PMID: 28933967 DOI: 10.1080/08830185.2017.1369980] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Activation-induced cytidine deaminase (AID), primarily expressed in activated mature B lymphocytes in germinal centers, is the key factor in adaptive immune response against foreign antigens. AID is responsible for producing high-affinity and high-specificity antibodies against an infectious agent, through the physiological DNA alteration processes of antibody genes by somatic hypermutation (SHM) and class-switch recombination (CSR) and functions by deaminating deoxycytidines (dC) to deoxyuridines (dU), thereby introducing point mutations and double-stranded chromosomal breaks (DSBs). The beneficial physiological role of AID in antibody diversification is outweighed by its detrimental role in the genesis of several chronic immune diseases, under non-physiological conditions. This review offers a comprehensive and better understanding of AID biology and its pathological aspects, as well as addresses the challenges involved in AID-related cancer therapeutics, based on various recent advances and evidence available in the literature till date. In this article, we discuss ways through which our interpretation of AID biology may reflect upon novel clinical insights, which could be successfully translated into designing clinical trials and improving patient prognosis and disease management.
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Affiliation(s)
- Meenal Choudhary
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Anubhav Tamrakar
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Amit Kumar Singh
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Monika Jain
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Ankit Jaiswal
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
| | - Prashant Kodgire
- a Centre for Biosciences and Biomedical Engineering , Indian Institute of Technology Indore , Simrol , Indore , Madhya Pradesh , India
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23
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Cisneros L, Bussey KJ, Orr AJ, Miočević M, Lineweaver CH, Davies P. Ancient genes establish stress-induced mutation as a hallmark of cancer. PLoS One 2017; 12:e0176258. [PMID: 28441401 PMCID: PMC5404761 DOI: 10.1371/journal.pone.0176258] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 04/08/2017] [Indexed: 02/07/2023] Open
Abstract
Cancer is sometimes depicted as a reversion to single cell behavior in cells adapted to live in a multicellular assembly. If this is the case, one would expect that mutation in cancer disrupts functional mechanisms that suppress cell-level traits detrimental to multicellularity. Such mechanisms should have evolved with or after the emergence of multicellularity. This leads to two related, but distinct hypotheses: 1) Somatic mutations in cancer will occur in genes that are younger than the emergence of multicellularity (1000 million years [MY]); and 2) genes that are frequently mutated in cancer and whose mutations are functionally important for the emergence of the cancer phenotype evolved within the past 1000 million years, and thus would exhibit an age distribution that is skewed to younger genes. In order to investigate these hypotheses we estimated the evolutionary ages of all human genes and then studied the probability of mutation and their biological function in relation to their age and genomic location for both normal germline and cancer contexts. We observed that under a model of uniform random mutation across the genome, controlled for gene size, genes less than 500 MY were more frequently mutated in both cases. Paradoxically, causal genes, defined in the COSMIC Cancer Gene Census, were depleted in this age group. When we used functional enrichment analysis to explain this unexpected result we discovered that COSMIC genes with recessive disease phenotypes were enriched for DNA repair and cell cycle control. The non-mutated genes in these pathways are orthologous to those underlying stress-induced mutation in bacteria, which results in the clustering of single nucleotide variations. COSMIC genes were less common in regions where the probability of observing mutational clusters is high, although they are approximately 2-fold more likely to harbor mutational clusters compared to other human genes. Our results suggest this ancient mutational response to stress that evolved among prokaryotes was co-opted to maintain diversity in the germline and immune system, while the original phenotype is restored in cancer. Reversion to a stress-induced mutational response is a hallmark of cancer that allows for effectively searching “protected” genome space where genes causally implicated in cancer are located and underlies the high adaptive potential and concomitant therapeutic resistance that is characteristic of cancer.
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Affiliation(s)
- Luis Cisneros
- NantOmics, Tempe, Arizona, United States of America
- BEYOND Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona, United States of America
| | - Kimberly J. Bussey
- NantOmics, Tempe, Arizona, United States of America
- Department of Biomedical Informatics, Arizona State University, Tempe, Arizona, United States of America
- * E-mail:
| | - Adam J. Orr
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Milica Miočević
- Department of Psychology, Arizona State University, Tempe, Arizona, United States of America
| | - Charles H. Lineweaver
- Planetary Science Institute, Research School of Astronomy and Astrophysics and Research School of Earth Sciences, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Paul Davies
- BEYOND Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona, United States of America
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24
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Mutational landscape of antibody variable domains reveals a switch modulating the interdomain conformational dynamics and antigen binding. Proc Natl Acad Sci U S A 2017; 114:E486-E495. [PMID: 28057863 DOI: 10.1073/pnas.1613231114] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Somatic mutations within the antibody variable domains are critical to the immense capacity of the immune repertoire. Here, via a deep mutational scan, we dissect how mutations at all positions of the variable domains of a high-affinity anti-VEGF antibody G6.31 impact its antigen-binding function. The resulting mutational landscape demonstrates that large portions of antibody variable domain positions are open to mutation, and that beneficial mutations can be found throughout the variable domains. We determine the role of one antigen-distal light chain position 83, demonstrating that mutation at this site optimizes both antigen affinity and thermostability by modulating the interdomain conformational dynamics of the antigen-binding fragment. Furthermore, by analyzing a large number of human antibody sequences and structures, we demonstrate that somatic mutations occur frequently at position 83, with corresponding domain conformations observed for G6.31. Therefore, the modulation of interdomain dynamics represents an important mechanism during antibody maturation in vivo.
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25
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Bashford-Rogers RJM, Nicolaou KA, Bartram J, Goulden NJ, Loizou L, Koumas L, Chi J, Hubank M, Kellam P, Costeas PA, Vassiliou GS. Eye on the B-ALL: B-cell receptor repertoires reveal persistence of numerous B-lymphoblastic leukemia subclones from diagnosis to relapse. Leukemia 2016; 30:2312-2321. [PMID: 27211266 PMCID: PMC5155029 DOI: 10.1038/leu.2016.142] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 05/02/2016] [Accepted: 05/12/2016] [Indexed: 02/08/2023]
Abstract
The strongest predictor of relapse in B-cell acute lymphoblastic leukemia (B-ALL) is the level of persistence of tumor cells after initial therapy. The high mutation rate of the B-cell receptor (BCR) locus allows high-resolution tracking of the architecture, evolution and clonal dynamics of B-ALL. Using longitudinal BCR repertoire sequencing, we find that the BCR undergoes an unexpectedly high level of clonal diversification in B-ALL cells through both somatic hypermutation and secondary rearrangements, which can be used for tracking the subclonal composition of the disease and detect minimal residual disease with unprecedented sensitivity. We go on to investigate clonal dynamics of B-ALL using BCR phylogenetic analyses of paired diagnosis-relapse samples and find that large numbers of small leukemic subclones present at diagnosis re-emerge at relapse alongside a dominant clone. Our findings suggest that in all informative relapsed patients, the survival of large numbers of clonogenic cells beyond initial chemotherapy is a surrogate for inherent partial chemoresistance or inadequate therapy, providing an increased opportunity for subsequent emergence of fully resistant clones. These results frame early cytoreduction as an important determinant of long-term outcome.
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Affiliation(s)
- R J M Bashford-Rogers
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.,Department of Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - K A Nicolaou
- The Center for the Study of Hematological Malignancies, Nicosia, Cyprus
| | - J Bartram
- Department of Haematology, Great Ormond Street Hospital for Children, London, UK.,Genetics and Genomic Medicine Programme, UCL Institute of Child Health, London, UK
| | - N J Goulden
- Department of Haematology, Great Ormond Street Hospital for Children, London, UK
| | - L Loizou
- Pediatric Oncology/Hematology Clinic, Nicosia, Cyprus
| | - L Koumas
- The Center for the Study of Hematological Malignancies, Nicosia, Cyprus
| | - J Chi
- The Center for the Study of Hematological Malignancies, Nicosia, Cyprus
| | - M Hubank
- Genetics and Genomic Medicine Programme, UCL Institute of Child Health, London, UK
| | - P Kellam
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.,Division of Infection and Immunity, Research Department of Infection, University College London, London, UK
| | - P A Costeas
- The Center for the Study of Hematological Malignancies, Nicosia, Cyprus
| | - G S Vassiliou
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.,The Center for the Study of Hematological Malignancies, Nicosia, Cyprus.,Cambridge Blood and Stem Cell Biobank and Cancer Molecular Diagnosis Laboratory, Cambridge Biomedical Research Centre, Cambridge, UK
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26
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Klarenbeek A, El Mazouari K, Desmyter A, Blanchetot C, Hultberg A, de Jonge N, Roovers RC, Cambillau C, Spinelli S, Del-Favero J, Verrips T, de Haard HJ, Achour I. Camelid Ig V genes reveal significant human homology not seen in therapeutic target genes, providing for a powerful therapeutic antibody platform. MAbs 2016; 7:693-706. [PMID: 26018625 DOI: 10.1080/19420862.2015.1046648] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Camelid immunoglobulin variable (IGV) regions were found homologous to their human counterparts; however, the germline V repertoires of camelid heavy and light chains are still incomplete and their therapeutic potential is only beginning to be appreciated. We therefore leveraged the publicly available HTG and WGS databases of Lama pacos and Camelus ferus to retrieve the germline repertoire of V genes using human IGV genes as reference. In addition, we amplified IGKV and IGLV genes to uncover the V germline repertoire of Lama glama and sequenced BAC clones covering part of the Lama pacos IGK and IGL loci. Our in silico analysis showed that camelid counterparts of all human IGKV and IGLV families and most IGHV families could be identified, based on canonical structure and sequence homology. Interestingly, this sequence homology seemed largely restricted to the Ig V genes and was far less apparent in other genes: 6 therapeutically relevant target genes differed significantly from their human orthologs. This contributed to efficient immunization of llamas with the human proteins CD70, MET, interleukin (IL)-1β and IL-6, resulting in large panels of functional antibodies. The in silico predicted human-homologous canonical folds of camelid-derived antibodies were confirmed by X-ray crystallography solving the structure of 2 selected camelid anti-CD70 and anti-MET antibodies. These antibodies showed identical fold combinations as found in the corresponding human germline V families, yielding binding site structures closely similar to those occurring in human antibodies. In conclusion, our results indicate that active immunization of camelids can be a powerful therapeutic antibody platform.
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Key Words
- BLAST, basic local alignment search tools
- CDR
- CDR, complementarity-determining region
- FR
- FR, framework region
- HTG, High-Throughput Genomic database
- IGHV, immunoglobulin heavy chain variable region gene
- IGKV, immunoglobulin light chain kappa variable region gene
- IGLV, immunoglobulin light chain lambda variable region gene
- IgG
- PDB, Protein Data Bank
- V family/genes, variable region family/genes
- VH, light chain variable region
- Vκ, light chain kappa variable region
- Vλ, light chain lambda variable region
- WGS, Whole Genome Shotgun database
- antibodies
- biologics
- camelid
- canonical folds
- germline variable genes
- human sequence and structural homology
- sequence mining
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Affiliation(s)
- Alex Klarenbeek
- a Department of Cell Biology; Utrecht University ; Utrecht , The Netherlands
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27
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Kaur H, Salunke DM. Antibody promiscuity: Understanding the paradigm shift in antigen recognition. IUBMB Life 2015; 67:498-505. [DOI: 10.1002/iub.1397] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 06/16/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Harmeet Kaur
- Regional Centre for Biotechnology, Biotech Science Cluster; Faridabad 121001 Haryana India
- Manipal University; 576104 Karnataka India
| | - Dinakar M. Salunke
- Regional Centre for Biotechnology, Biotech Science Cluster; Faridabad 121001 Haryana India
- National Institute of Immunology; New Delhi 110067 India
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28
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Freund NT, Scheid JF, Mouquet H, Nussenzweig MC. Amplification of highly mutated human Ig lambda light chains from an HIV-1 infected patient. J Immunol Methods 2015; 418:61-5. [PMID: 25667013 DOI: 10.1016/j.jim.2015.01.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/28/2015] [Accepted: 01/29/2015] [Indexed: 10/24/2022]
Abstract
Isolation and characterization of anti HIV-1 broadly neutralizing antibodies (bNAbs) have elucidated new epitopes and sites of viral vulnerability. Anti-HIV-1 bNAbs typically show high levels of somatic mutations in their variable region genes. This feature potentially limits antibody identification, since the mutated antibody sequences are no longer complimentary to primers designed based on germline antibody sequences. Here we report a new set of primers for Igλ light chains that aligns to the 5' end of the leader sequence and is highly efficient for the amplification of antibodies that contain mutations and deletions in the 5' end of human Igλ.
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Affiliation(s)
- Natalia T Freund
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Johannes F Scheid
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA
| | - Hugo Mouquet
- Laboratory of Humoral Response to Pathogens, Department of Immunology, Institut Pasteur, Paris 75015, France
| | - Michel C Nussenzweig
- Laboratory of Molecular Immunology, The Rockefeller University, New York, NY 10065, USA; Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
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29
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Saini J, Hershberg U. B cell variable genes have evolved their codon usage to focus the targeted patterns of somatic mutation on the complementarity determining regions. Mol Immunol 2015; 65:157-67. [PMID: 25660968 DOI: 10.1016/j.molimm.2015.01.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 11/29/2014] [Accepted: 01/02/2015] [Indexed: 01/19/2023]
Abstract
The exceptional ability of B cells to diversify through somatic mutation and improve affinity of the repertoire toward the antigens is the cornerstone of adaptive immunity. Somatic mutation is not evenly distributed and exhibits certain micro-sequence specificities. We show here that the combination of somatic mutation targeting and the codon usage in human B cell receptor (BCR) Variable (V) genes create expected patterns of mutation and post mutation changes that are focused on their complementarity determining regions (CDR). T cell V genes are also skewed in targeting mutations but to a lesser extent and are lacking the codon usage bias observed in BCRs. This suggests that the observed skew in T cell receptors is due to their amino acid usage, which is similar to that of BCRs. The mutation targeting and the codon bias allow B cell CDRs to diversify by specifically accumulating nonconservative changes. We counted the distribution of mutations to CDR in 4 different human datasets. In all four cases we found that the number of actual mutations in the CDR correlated significantly with the V gene mutation biases to the CDR predicted by our models. Finally, it appears that the mutation bias in V genes indeed relates to their long-term survival in actual human repertoires. We observed that resting repertoires of B cells overexpressed V genes that were especially biased toward focused mutation and change in the CDR. This bias in V gene usage was somewhat relaxed at the height of the immune response to a vaccine, presumably because of the need for a wider diversity in a primary response. However, older patients did not retain this flexibility and were biased toward using only highly skewed V genes at all stages of their response.
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Affiliation(s)
- Jasmine Saini
- School of Biomedical Engineering Sciences and Health Systems, Drexel University, Philadelphia, PA 19104, United States
| | - Uri Hershberg
- School of Biomedical Engineering Sciences and Health Systems, Drexel University, Philadelphia, PA 19104, United States; Department of Microbiology and Immunology, College of Medicine, Drexel University, Philadelphia, PA 19104, United States.
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30
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Ahmadzadeh V, Farajnia S, Feizi MAH, Nejad RAK. Antibody humanization methods for development of therapeutic applications. Monoclon Antib Immunodiagn Immunother 2014; 33:67-73. [PMID: 24746146 DOI: 10.1089/mab.2013.0080] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Recombinant antibody technologies are rapidly becoming available and showing considerable clinical success. However, the immunogenicity of murine-derived monoclonal antibodies is restrictive in cancer immunotherapy. Humanized antibodies can overcome these problems and are considered to be a promising alternative therapeutic agent. There are several approaches for antibody humanization. In this article we review various methods used in the antibody humanization process.
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Affiliation(s)
- Vahideh Ahmadzadeh
- 1 Biotechnology Research Center, Tabriz University of Medical Sciences , Tabriz, Iran
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31
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Rogosch T, Kerzel S, Dey F, Wagner JJ, Zhang Z, Maier RF, Zemlin M. IgG4 and IgE transcripts in childhood allergic asthma reflect divergent antigen-driven selection. THE JOURNAL OF IMMUNOLOGY 2014; 193:5801-8. [PMID: 25385824 DOI: 10.4049/jimmunol.1401409] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The physiologic function of the "odd" Ab IgG4 remains enigmatic. IgG4 mediates immunotolerance, as, for example, during specific immunotherapy of allergies, but it mediates tissue damage in autoimmune pemphigus vulgaris and "IgG4-related disease." Approximately half of the circulating IgG4 molecules are bispecific owing to their unique ability to exchange half-molecules. Better understanding of the interrelation between IgG4 and IgE repertoires may yield insight into the pathogenesis of allergies and into potential novel therapies that modulate IgG4 responses. We aimed to compare the selective forces that forge the IgG4 and IgE repertoires in allergic asthma. Using an IgG4-specific RT-PCR, we amplified, cloned, and sequenced IgG4 H chain transcripts of PBMCs from 10 children with allergic asthma. We obtained 558 functional IgG4 sequences, of which 286 were unique. Compared with previously published unique IgE transcripts from the same blood samples, the somatic mutation rate was significantly enhanced in IgG4 transcripts (62 versus 83%; p < 0.001), whereas fewer IgG4 sequences displayed statistical evidence of Ag-driven selection (p < 0.001). On average, the hypervariable CDRH3 region was four nucleotides shorter in IgG4 than in IgE transcripts (p < 0.001). IgG4 transcripts in the circulation of children with allergic asthma reflect some characteristics of classical Ag-driven B2 immune responses but display less indication of Ag selection than do IgE transcripts. Although allergen-specific IgG4 can block IgE-mediated allergen presentation and degranulation of mast cells, key factors that influence the Ag-binding properties of the Ab differ between the overall repertoires of circulating IgG4- and IgE-expressing cells.
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Affiliation(s)
- Tobias Rogosch
- Department of Pediatrics, Philipps-University Marburg, D-35033 Marburg, Germany
| | - Sebastian Kerzel
- Department of Pediatric Pneumology and Allergy, University Children's Hospital Regensburg, St. Hedwig Campus, 93053 Regensburg, Germany; and
| | - Friederike Dey
- Department of Pediatrics, Philipps-University Marburg, D-35033 Marburg, Germany
| | | | - Zhixin Zhang
- Department of Pathology and Microbiology, Eppley Institute for Research in Cancer, University of Nebraska Medical Center, Omaha, NE 68198
| | - Rolf F Maier
- Department of Pediatrics, Philipps-University Marburg, D-35033 Marburg, Germany
| | - Michael Zemlin
- Department of Pediatrics, Philipps-University Marburg, D-35033 Marburg, Germany;
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32
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Umiker BR, McDonald G, Larbi A, Medina CO, Hobeika E, Reth M, Imanishi-Kari T. Production of IgG autoantibody requires expression of activation-induced deaminase in early-developing B cells in a mouse model of SLE. Eur J Immunol 2014; 44:3093-108. [PMID: 25044405 DOI: 10.1002/eji.201344282] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 06/13/2014] [Accepted: 07/09/2014] [Indexed: 11/06/2022]
Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of pathogenic IgG antinuclear antibodies. Pathogenic IgG autoantibody production requires B-cell activation, leading to the production of activation-induced deaminase (AID) and class switching of IgM genes to IgG. To understand how and when B cells are activated to produce these IgG autoantibodies, we studied cells from 564Igi, a mouse model of SLE. 564Igi mice develop a disease profile closely resembling that found in human SLE patients, including the presence of IgG antinucleic acid Abs. We have generated 564Igi mice that conditionally express an activation-induced cytidine deaminase transgene (Aicda(tg) ), either in all B cells or only in mature B cells. Here, we show that class-switched pathogenic IgG autoantibodies were produced only in 564Igi mice in which AID was functional in early-developing B cells, resulting in loss of tolerance. Furthermore, we show that the absence of AID in early-developing B cells also results in increased production of self-reactive IgM, indicating that AID, through somatic hypermutation, contributes to tolerance. Our results suggest that the pathophysiology of clinical SLE might also be dependent on AID expression in early-developing B cells.
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Affiliation(s)
- Benjamin R Umiker
- Graduate Program in Immunology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA; Department of Integrative Physiology and Pathobiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA
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33
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Design, expression and characterization of a single chain anti-CD20 antibody; a germline humanized antibody derived from Rituximab. Protein Expr Purif 2014; 102:45-51. [PMID: 25088934 DOI: 10.1016/j.pep.2014.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 07/20/2014] [Accepted: 07/22/2014] [Indexed: 12/31/2022]
Abstract
CD20 is a B cell lineage specific surface antigen involved in various B cell malignancies. So far, several murine and chimeric antibodies have been produced against this antigen among which Rituximab is a commercially approved antibody widely used in treatment of cancers associated with CD20 overexpression. The current study reports the production and characterization of a humanized single chain version of Rituximab through CDR grafting method. For either heavy or light chain variable domains, a human antibody with the highest sequence homology to Rituximab was selected from human germline sequences and used as framework donors. Vernier zone residues in framework regions were replaced with those of Rituximab to retain the antigen binding affinity of parental antibody. The reactivity of humanized single chain antibody with CD20 was examined by ELISA and dot blot assays. The ability of antibody to suppress the growth of CD20 overexpressing Raji cells was tested by MTT assay. Analysis of reactivity with CD20 antigen revealed that the humanized single chain antibody reacted to the target antigen with high affinity. Proliferation inhibition assay showed that humanized scFv could suppress the proliferation of Raji cells efficiently in a dose-dependent manner. This successful production of a humanized scFv with the ability to inhibit growth of CD20-expressing cancer cell may provide a promising alternative strategy for CD20 targeted therapy.
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34
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Briney BS, Willis JR, Finn JA, McKinney BA, Crowe JE. Tissue-specific expressed antibody variable gene repertoires. PLoS One 2014; 9:e100839. [PMID: 24956460 PMCID: PMC4067404 DOI: 10.1371/journal.pone.0100839] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Accepted: 05/30/2014] [Indexed: 01/05/2023] Open
Abstract
Recent developments in genetic technologies allow deep analysis of the sequence diversity of immune repertoires, but little work has been reported on the architecture of immune repertoires in mucosal tissues. Antibodies are the key to prevention of infections at the mucosal surface, but it is currently unclear whether the B cell repertoire at mucosal surfaces reflects the dominant antibodies found in the systemic compartment or whether mucosal tissues harbor unique repertoires. We examined the expressed antibody variable gene repertoires from 10 different human tissues using RNA samples derived from a large number of individuals. The results revealed that mucosal tissues such as stomach, intestine and lung possess unique antibody gene repertoires that differed substantially from those found in lymphoid tissues or peripheral blood. Mutation frequency analysis of mucosal tissue repertoires revealed that they were highly mutated, with little evidence for the presence of naïve B cells, in contrast to blood. Mucosal tissue repertoires possessed longer heavy chain complementarity determining region 3 loops than lymphoid tissue repertoires. We also noted a large increase in frequency of both insertions and deletions in the small intestine antibody repertoire. These data suggest that mucosal immune repertoires are distinct in many ways from the systemic compartment.
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Affiliation(s)
- Bryan S. Briney
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Jordan R. Willis
- The Chemical and Physical Biology Program, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Jessica A. Finn
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Brett A. McKinney
- Tandy School of Computer Science and Department of Mathematics, University of Tulsa, Tulsa, Oklahoma, United States of America
| | - James E. Crowe
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- * E-mail:
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35
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Fundamental characteristics of the expressed immunoglobulin VH and VL repertoire in different canine breeds in comparison with those of humans and mice. Mol Immunol 2014; 59:71-8. [DOI: 10.1016/j.molimm.2014.01.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 01/12/2014] [Accepted: 01/13/2014] [Indexed: 11/19/2022]
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36
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Prado C, Rodríguez M, Cortegano I, Ruiz C, Alía M, de Andrés B, Gaspar ML. Postnatal and adult immunoglobulin repertoires of innate-like CD19(+)CD45R(lo) B Cells. J Innate Immun 2014; 6:499-514. [PMID: 24603602 DOI: 10.1159/000358237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 12/27/2013] [Indexed: 01/06/2023] Open
Abstract
The diversity in antibody repertoire relies on different B cell populations working efficiently to fulfil distinct specific functions. We recently described an innate-like CD19(+)CD45R(-/lo) (19(+)45R(lo)) cell population in postnatal unstimulated adult mice, a heterogeneous population containing cells expressing immunoglobulin M (IgM) and others behaving as differentiated mature B lymphocytes (intracytoplasmic IgG1, AID(+), Blimp-1(+)RAG2(-)). In the present study, we characterized the Ig repertoire expressed by splenic 19(+)45R(lo) cells, assuming that they would bear a restricted repertoire biased for germline rearrangements and low mutation rates similar to other innate-like cells. Sequences from 19(+)45R(lo) cells displayed a variety of V, D and J regions, and the analysis of the CDR-H3 region revealed an intermediate overall CDR-H3 length and moderate hydrophobicity. Both IgM and switched sequences of PD15 19(+)45R(lo) cells had shorter CDR-H3 region and fewer non-template N nucleotides than adult sequences, as expected for profiles that correspond to an immature phenotype. Regarding the mutation rate in the VH regions, IgG1 sequences already carried a high rate of replacement mutations at PD15, which increased further in the sequences obtained from adult mice. Moreover, statistical models suggest that a proportion of the switched sequences in adult 19(+)45R(lo) cells had experienced antigen selection, unlike other innate-like B cell compartments.
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Affiliation(s)
- Carmen Prado
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
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37
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Rahman A, Giles IP. Structure and function of autoantibodies and their role in autoimmune rheumatic diseases. Expert Rev Clin Immunol 2014; 2:225-36. [DOI: 10.1586/1744666x.2.2.225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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38
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Kim HY, Stojadinovic A, Izadjoo MJ. Affinity maturation of monoclonal antibodies by multi-site-directed mutagenesis. Methods Mol Biol 2014; 1131:407-420. [PMID: 24515479 DOI: 10.1007/978-1-62703-992-5_24] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
High-affinity antibodies are crucial for development of monoclonal antibody (MAb)-based therapeutics for human diseases. Many new detailed methods for affinity maturation have been developed to improve MAb qualities by site-directed mutagenesis, chain shuffling, and error-prone PCR. Site-directed mutagenesis on hotspots in variable heavy (VH) complementary-determining region (CDR) 3 is a commonly used method for improving therapeutic potency and efficacy of targeted MAbs. Strategies for affinity maturation via multi-site-directed mutagenesis in VH-CDR3 described here are for valuable technical tool in the armamentarium of immunologists for development of fast-performance MAbs. Our strategy includes (1) selection of targeted MAb, (2) replacement of certain amino acid residues (e.g., negative or neutral charge to positive amino acids) in VH-CDR3, and (3) determination of binding activity to a target antigen.
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Affiliation(s)
- Hyung-Yong Kim
- Diagnostics and Translational Research Center, Henry M. Jackson Foundation for the Advancement of Military Medicine, Gaithersburg, MD, USA
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39
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Jang EJ, Jung KY, Hwang E, Jang YJ. Characterization of human anti-heat shock protein 60 monoclonal autoantibody Fab fragments in atherosclerosis: Genetic and functional analysis. Mol Immunol 2013; 54:338-46. [DOI: 10.1016/j.molimm.2012.12.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 12/13/2012] [Accepted: 12/15/2012] [Indexed: 01/08/2023]
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40
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Nishana M, Raghavan SC. Role of recombination activating genes in the generation of antigen receptor diversity and beyond. Immunology 2013; 137:271-81. [PMID: 23039142 DOI: 10.1111/imm.12009] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 08/19/2012] [Accepted: 08/21/2012] [Indexed: 01/18/2023] Open
Abstract
V(D)J recombination is the process by which antibody and T-cell receptor diversity is attained. During this process, antigen receptor gene segments are cleaved and rejoined by non-homologous DNA end joining for the generation of combinatorial diversity. The major players of the initial process of cleavage are the proteins known as RAG1 (recombination activating gene 1) and RAG2. In this review, we discuss the physiological function of RAGs as a sequence-specific nuclease and its pathological role as a structure-specific nuclease. The first part of the review discusses the basic mechanism of V(D)J recombination, and the last part focuses on how the RAG complex functions as a sequence-specific and structure-specific nuclease. It also deals with the off-target cleavage of RAGs and its implications in genomic instability.
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41
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Finlay WJJ, Almagro JC. Natural and man-made V-gene repertoires for antibody discovery. Front Immunol 2012; 3:342. [PMID: 23162556 PMCID: PMC3498902 DOI: 10.3389/fimmu.2012.00342] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Accepted: 10/27/2012] [Indexed: 01/15/2023] Open
Abstract
Antibodies are the fastest-growing segment of the biologics market. The success of antibody-based drugs resides in their exquisite specificity, high potency, stability, solubility, safety, and relatively inexpensive manufacturing process in comparison with other biologics. We outline here the structural studies and fundamental principles that define how antibodies interact with diverse targets. We also describe the antibody repertoires and affinity maturation mechanisms of humans, mice, and chickens, plus the use of novel single-domain antibodies in camelids and sharks. These species all utilize diverse evolutionary solutions to generate specific and high affinity antibodies and illustrate the plasticity of natural antibody repertoires. In addition, we discuss the multiple variations of man-made antibody repertoires designed and validated in the last two decades, which have served as tools to explore how the size, diversity, and composition of a repertoire impact the antibody discovery process.
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42
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González-Muñoz A, Bokma E, O’Shea D, Minton K, Strain M, Vousden K, Rossant C, Jermutus L, Minter R. Tailored amino acid diversity for the evolution of antibody affinity. MAbs 2012; 4:664-72. [PMID: 22926024 PMCID: PMC3502233 DOI: 10.4161/mabs.21728] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Antibodies are a unique class of proteins with the ability to adapt their binding sites for high affinity and high specificity to a multitude of antigens. Many analyses have been performed on antibody sequences and structures to elucidate which amino acids have a predominant role in antibody interactions with antigens. These studies have generally not distinguished between amino acids selected for broad antigen specificity in the primary immune response and those selected for high affinity in the secondary immune response. By studying a large data set of affinity matured antibodies derived from in vitro directed evolution experiments, we were able to specifically highlight a subset of amino acids associated with affinity improvements. In a comparison of affinity maturations using either tailored or full amino acid diversification, the tailored approach was found to be at least as effective at improving affinity while requiring fewer mutagenesis libraries than the traditional method. The resulting sequence data also highlight the potential for further reducing amino acid diversity for high affinity binding interactions.
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Selection of antibodies from synthetic antibody libraries. Arch Biochem Biophys 2012; 526:87-98. [DOI: 10.1016/j.abb.2011.12.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2011] [Revised: 12/27/2011] [Accepted: 12/30/2011] [Indexed: 11/21/2022]
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Hu WG, Yin J, Chau D, Negrych LM, Cherwonogrodzky JW. Humanization and characterization of an anti-ricin neutralization monoclonal antibody. PLoS One 2012; 7:e45595. [PMID: 23049820 PMCID: PMC3458913 DOI: 10.1371/journal.pone.0045595] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 08/21/2012] [Indexed: 01/02/2023] Open
Abstract
Ricin is regarded as a high terrorist risk for the public due to its high toxicity and ease of production. Currently, there is no therapeutic or vaccine available against ricin. D9, a murine monoclonal antibody developed previously in our laboratory, can strongly neutralize ricin and is therefore a good candidate for humanization. Humanization of D9 variable regions was achieved by a complementarity-determining region grafting approach. The humanized D9 (hD9) variable regions were further grafted onto human heavy and light chain constant regions to assemble the complete antibody gene. A foot-and-mouth-disease virus-derived 2A self-processing sequence was introduced between heavy and light chain DNA sequences to cleave the recombinant protein into a functional full-length antibody molecule from a single open reading frame driven by a single promoter in an adenoviral vector. After expression in mammalian cells and purification, the hD9 was demonstrated to have equimolar expression of the full-length antibody heavy and light chains. More importantly, the hD9 exhibited high affinity to ricin with KD of 1.63 nM, comparable to its parental murine D9 (2.55 nM). In a mouse model, intraperitoneal (i.p.) administration of hD9, at a low dose of 5 µg per mouse, 4 hours after the i.p. challenge with 5×LD50 ricin was found to rescue 100% of the mice. In addition, administered 6 hours post-challenge, hD9 could still rescue 50% of the mice. The hD9 has the potential to be used for prophylactic or therapeutic purposes against ricin poisoning.
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MESH Headings
- Adenoviridae/genetics
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal, Humanized/genetics
- Antibodies, Monoclonal, Humanized/immunology
- Antibodies, Monoclonal, Humanized/pharmacokinetics
- Antibodies, Monoclonal, Humanized/therapeutic use
- Antibody Affinity
- Antitoxins/genetics
- Antitoxins/immunology
- Antitoxins/therapeutic use
- Chemical Warfare Agents/poisoning
- Complementarity Determining Regions/genetics
- Complementarity Determining Regions/immunology
- DNA, Viral/genetics
- DNA, Viral/metabolism
- Female
- Foot-and-Mouth Disease Virus/genetics
- Genetic Vectors
- Half-Life
- Humans
- Immunoglobulin Heavy Chains/genetics
- Immunoglobulin Heavy Chains/immunology
- Immunoglobulin Light Chains/genetics
- Immunoglobulin Light Chains/immunology
- Injections, Intraperitoneal
- Mice
- Models, Molecular
- Molecular Sequence Data
- Plant Poisoning/immunology
- Plant Poisoning/mortality
- Plant Poisoning/prevention & control
- Protein Engineering
- Ricin/poisoning
- Survival Rate
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Affiliation(s)
- Wei-Gang Hu
- Defence Research and Development Canada - Suffield, Medicine Hat, Alberta, Canada.
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Ducancel F, Muller BH. Molecular engineering of antibodies for therapeutic and diagnostic purposes. MAbs 2012; 4:445-57. [PMID: 22684311 DOI: 10.4161/mabs.20776] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
During the past ten years, monoclonal antibodies (mAbs) have taken center stage in the field of targeted therapy and diagnosis. This increased interest in mAbs is due to their binding accuracy (affinity and specificity) together with the original molecular and structural rules that govern interactions with their cognate antigen. In addition, the effector properties of antibodies constitute a second major advantage associated with their clinical use. The development of molecular and structural engineering and more recently of in vitro evolution of antibodies has opened up new perspectives in the de novo design of antibodies more adapted to clinical and diagnostic use. Thus, efforts are regularly made by researchers to improve or modulate antibody recognition properties, to adapt their pharmacokinetics, engineer their stability, and control their immunogenicity. This review presents the latest molecular engineering results on mAbs with therapeutic and diagnostic applications.
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Affiliation(s)
- Frédéric Ducancel
- CEA, iBiTec-S, Department of Pharmacology and Immunoanalysis, Laboratory of Antibody Engineering for Health, Gif-sur-Yvette, France.
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Raghunathan G, Smart J, Williams J, Almagro JC. Antigen-binding site anatomy and somatic mutations in antibodies that recognize different types of antigens. J Mol Recognit 2012; 25:103-13. [PMID: 22407974 DOI: 10.1002/jmr.2158] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The number of antibody structures co-crystallized with their respective antigens has increased rapidly in the last few years, thus offering a formidable source of information to gain insight into the structure-function relationships of this family of proteins. We have analyzed here 140 unique middle-resolution to high-resolution (<3 Å) antibody structures, including 55 in complex with proteins, 39 with peptides, and 46 with haptens. We determined (i) length variations of the hypervariable loops, (ii) number of contacts with antigen, (iii) solvent accessible area buried upon binding, (iv) location and frequency of antigen contacting residues, (v) type of residues interacting with antigens, and (vi) putative somatic mutations. Except for somatic mutations, distinctive profiles were identified for all the variables analyzed. Compared with contacts, somatic mutations occurred with less abundance at any given position and extended beyond the regions in contact, with no clear difference among antibodies that recognize different types of antigens. This observation is consistent with the fact that although antigen recognition accomplished by shape and physicochemical complementarity is selective in nature, the somatic mutation process is stochastic and selection for mutations leading to improved affinity is not directly related to contact residues. Thus, the knowledge emerging from this study enhances our understanding of the structure-function relationship in antibodies while providing valuable guidance to design libraries for antibody discovery and optimization.
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High-throughput antibody sequencing reveals genetic evidence of global regulation of the naïve and memory repertoires that extends across individuals. Genes Immun 2012; 13:469-73. [PMID: 22622198 DOI: 10.1038/gene.2012.20] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vast diversity in the antibody repertoire is a key component of the adaptive immune response. This diversity is generated centrally through the assembly of variable, diversity and joining gene segments, and peripherally by somatic hypermutation and class-switch recombination. The peripheral diversification process is thought to only occur in response to antigenic stimulus, producing antigen-selected memory B cells. Surprisingly, analyses of the variable, diversity and joining gene segments have revealed that the naïve and memory subsets are composed of similar proportions of these elements. Lacking, however, is a more detailed study, analyzing the repertoires of naïve and memory subsets at the level of the complete V(D)J recombinant. This report presents a thorough examination of V(D)J recombinants in the human peripheral blood repertoire, revealing surprisingly large repertoire differences between circulating B-cell subsets and providing genetic evidence for global control of repertoire diversity in naïve and memory circulating B-cell subsets.
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Khan T, Salunke DM. Structural elucidation of the mechanistic basis of degeneracy in the primary humoral response. THE JOURNAL OF IMMUNOLOGY 2012; 188:1819-27. [PMID: 22266283 DOI: 10.4049/jimmunol.1102701] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The mechanistic basis for efficient combating of the infinite range of foreign Ags by the limited repertoire of naive Abs expressed on primary B cell surfaces during their first encounter was addressed through elegantly designed crystallographic analyses. Resolution of the discrepancy arising from the limited number of possible germline Ab receptors on primary B cells for recognizing the unlimited pool of possible Ags has been attempted by invoking the degenerate recognition potential of the germline Abs. Structural analyses of germline mAb BBE6.12H3 in an Ag-free state, as well as bound to four different peptide Ags, established the correlation of its degenerate specificity with conformational versatility of the paratope. Six distinct paratope topologies observed for a single germline mAb provided a quantitative description of the primary Ag recognition repertoire at the tertiary structural level. Each of the four different peptide Ags was bound specifically to a distinct conformation of the paratope, which was also different from that of the Ag-free states of the same germline mAb. A minimal conserved motif in the pristine Ag-combining site essential for multispecificity and Ag binding-mediated change in the elbow angle of Fab was also discernible. It is proposed that the generation of a primary Ab repertoire involves large, yet finite, germline Ab clones, each capable of adopting discrete conformations, which in turn exhibit diverse binding modes.
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Affiliation(s)
- Tarique Khan
- Structural Biology Unit, National Institute of Immunology, New Delhi 110 067, India
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Muller BH, Savatier A, L'Hostis G, Costa N, Bossus M, Michel S, Ott C, Becquart L, Ruffion A, Stura EA, Ducancel F. In Vitro Affinity Maturation of an Anti-PSA Antibody for Prostate Cancer Diagnostic Assay. J Mol Biol 2011; 414:545-62. [DOI: 10.1016/j.jmb.2011.10.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 08/30/2011] [Accepted: 10/05/2011] [Indexed: 11/28/2022]
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Nadav-Dagan L, Katz BZ. Malignant B-cell intra-clonal diversification: following the yarn in the labyrinth. Leuk Lymphoma 2011; 52:2050-6. [DOI: 10.3109/10428194.2011.587564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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