scholarly journals Signatures of selection in the human antibody repertoire: Selective sweeps, competing subclones, and neutral drift

2019 ◽  
Vol 116 (4) ◽  
pp. 1261-1266 ◽  
Author(s):  
Felix Horns ◽  
Christopher Vollmers ◽  
Cornelia L. Dekker ◽  
Stephen R. Quake

Antibodies are created and refined by somatic evolution in B cell populations, which endows the human immune system with the ability to recognize and eliminate diverse pathogens. However, the evolutionary processes that sculpt antibody repertoires remain poorly understood. Here, using an unbiased repertoire-scale approach, we show that the population genetic signatures of evolution are evident in human B cell lineages and reveal how antibodies evolve somatically. We measured the dynamics and genetic diversity of B cell responses in five adults longitudinally before and after influenza vaccination using high-throughput antibody repertoire sequencing. We identified vaccine-responsive B cell lineages that carry signatures of selective sweeps driven by positive selection, and discovered that they often display evidence for selective sweeps favoring multiple subclones. We also found persistent B cell lineages that exhibit stable population dynamics and carry signatures of neutral drift. By exploiting the relationship between B cell fitness and antibody binding affinity, we demonstrate the potential for using phylogenetic approaches to identify antibodies with high binding affinity. This quantitative characterization reveals that antibody repertoires are shaped by an unexpectedly broad spectrum of evolutionary processes and shows how signatures of evolutionary history can be harnessed for antibody discovery and engineering.

2017 ◽  
Author(s):  
Felix Horns ◽  
Christopher Vollmers ◽  
Cornelia L. Dekker ◽  
Stephen R. Quake

AbstractAntibodies are created and refined by somatic evolution in B cell populations, which endows the human immune system with the ability to recognize and eliminate diverse pathogens. However, the evolutionary processes that sculpt antibody repertoires remain poorly understood. Here, using an unbiased repertoire-scale approach, we show that the molecular signatures of evolution are evident in human B cell lineages and reveal how antibodies evolve somatically. We measured the dynamics and genetic diversity of B cell responses of five adults longitudinally before and after influenza vaccination using high-throughput antibody repertoire sequencing. We identified vaccine-responsive B cell lineages that carry signatures of selective sweeps driven by positive selection, and discovered that they often display evidence for selective sweeps favoring multiple subclones. We also found persistent B cell lineages that exhibit stable population dynamics and carry signatures of neutral drift. By exploiting the linkage between B cell fitness and antibody binding affinity, we demonstrated the potential for using signatures of selection to identify antibodies with high binding affinity. This quantitative characterization reveals that antibody repertoires are shaped by an unexpectedly broad spectrum of evolutionary processes and shows how signatures of evolutionary history can be harnessed for antibody discovery and engineering.One Sentence SummaryMolecular signatures of somatic evolution reveal that diverse evolutionary processes ranging from strong positive selection to neutral drift sculpt human antibodies.


2021 ◽  
Vol 12 ◽  
Author(s):  
Brian M. Petersen ◽  
Sophia A. Ulmer ◽  
Emily R. Rhodes ◽  
Matias F. Gutierrez-Gonzalez ◽  
Brandon J. Dekosky ◽  
...  

Monoclonal antibodies (mAbs) are an important class of therapeutics used to treat cancer, inflammation, and infectious diseases. Identifying highly developable mAb sequences in silico could greatly reduce the time and cost required for therapeutic mAb development. Here, we present position-specific scoring matrices (PSSMs) for antibody framework mutations developed using baseline human antibody repertoire sequences. Our analysis shows that human antibody repertoire-based PSSMs are consistent across individuals and demonstrate high correlations between related germlines. We show that mutations in existing therapeutic antibodies can be accurately predicted solely from baseline human antibody sequence data. We find that mAbs developed using humanized mice had more human-like FR mutations than mAbs originally developed by hybridoma technology. A quantitative assessment of entire framework regions of therapeutic antibodies revealed that there may be potential for improving the properties of existing therapeutic antibodies by incorporating additional mutations of high frequency in baseline human antibody repertoires. In addition, high frequency mutations in baseline human antibody repertoires were predicted in silico to reduce immunogenicity in therapeutic mAbs due to the removal of T cell epitopes. Several therapeutic mAbs were identified to have common, universally high-scoring framework mutations, and molecular dynamics simulations revealed the mechanistic basis for the evolutionary selection of these mutations. Our results suggest that baseline human antibody repertoires may be useful as predictive tools to guide mAb development in the future.


2015 ◽  
Author(s):  
Nicolas Strauli ◽  
Ryan Hernandez

AbstractBackgroundVaccines dramatically affect an individual’s adaptive immune system, and thus provide an excellent means to study human immunity. Upon vaccination, the B cells that express antibodies (Abs) that happen to bind the vaccine are stimulated to proliferate and undergo mutagenesis at their Ab locus. This process may alter the composition of B cell lineages within an individual, which are known collectively as the antibody repertoire (AbR). Antibodies are also highly expressed in whole blood, potentially enabling unbiased RNA sequencing technologies to query this diversity. Less is known about the diversity of AbR responses across individuals to a given vaccine and if individuals tend to yield a similar response to the same antigenic stimulus.MethodsHere we implement a bioinformatic pipeline that extracts the AbR information from a time-series RNA-seq dataset of 5 patients who were administered a seasonal trivalent influenza vaccine (TIV). We harness the detailed time-series nature of this dataset and use methods based in functional data analysis (FDA) to identify the B cell lineages that respond to the vaccine. We then design and implement rigorous statistical tests in order to ask whether or not these patients exhibit a convergent AbR response to the same TIV.ResultsWe find that high-resolution time-series data can be used to help identify the Ab lineages that respond to an antigenic stimulus, and that this response can exhibit a convergent nature across patients inoculated with the same vaccine. However, correlations in AbR diversity among individuals prior to inoculation can confound inference of a convergent signal unless it is taken into account.ConclusionsWe developed a framework to identify the elements of an AbR that respond to an antigen. This information could be used to understand the diversity of different immune responses in different individuals, as well as to gauge the effectiveness of the immune response to a given stimulus within an individual. We also present a framework for testing a convergent hypothesis between AbRs; a hypothesis that is more difficult to test than previously appreciated. Our discovery of a convergent signal suggests that similar epitopes do select for antibodies with similar sequence characteristics.


2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Liangliang Jiang ◽  
Tao Jiang ◽  
Jianhua Luo ◽  
Yanliang Kang ◽  
Yue Tong ◽  
...  

Single B cell antibody technology is a method for isolating antigen-specific B cells from human peripheral blood and obtaining antibody genes in developing antibody drugs. However, owing to immune tolerance to autoantigen, human autoantigen-specific B cells are difficult to acquire by conventional single B cell technology. In this study, we constructed a nitrated T-cell epitope named NitraTh by incorporating p-nitrophenylalanine into a universal T helper epitope. NitraTh had enhanced ability to activate CD4+ T cells and can be recognized by CD4+ T cells with different HLA class II haplotypes. This NitraTh can also break immune tolerance to autoantigens, such as human epidermal growth factor receptor 2 (HER2) and cannabinoid receptor 1, and induce strong specific IgM+ B cell responses in vitro. HER2-NitraTh vaccine can also stimulate the generation of HER2-specific IgG+ B cells in human immune system mice, which was established by cotransplanting lymphocytes and autologous dendritic cells in immunodeficient mice. We obtained 30 fully human IgG antibody genes by sorting single B cells from the human immune system mice immunized with HER2-NitraTh vaccine. The analysis of antibody genes showed that sorted B cells underwent the extensive somatic mutation of the antibody genes. We randomly selected eight genes for cloning, six of which expressed antibodies that can bind to HER2. Hence, we provided a convenient and effective method in acquiring fully human antibody genes against self-proteins, which can be used in developing therapeutic antibody drugs.


Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 13 ◽  
Author(s):  
Christoph Kreer ◽  
Henning Gruell ◽  
Thierry Mora ◽  
Aleksandra M. Walczak ◽  
Florian Klein

The human antibody repertoire is generated by the recombination of different gene segments as well as by processes of somatic mutation. Together these mechanisms result in a tremendous diversity of antibodies that are able to combat various pathogens including viruses and bacteria, or malignant cells. In this review, we summarize the opportunities and challenges that are associated with the analyses of the B cell receptor repertoire and the antigen-specific B cell response. We will discuss how recent advances have increased our understanding of the antibody response and how repertoire analyses can be exploited to inform on vaccine strategies, particularly against HIV-1.


2017 ◽  
Vol 2 (15) ◽  
pp. eaan8289 ◽  
Author(s):  
Charles F. A. de Bourcy ◽  
Cornelia L. Dekker ◽  
Mark M. Davis ◽  
Mark R. Nicolls ◽  
Stephen R. Quake

2014 ◽  
Vol 5 ◽  
Author(s):  
Eva Szymanska Mroczek ◽  
Gregory C. Ippolito ◽  
Tobias Rogosch ◽  
Kam Hon Hoi ◽  
Tracy A. Hwangpo ◽  
...  

2022 ◽  
Author(s):  
Elaine C. Chen ◽  
Pavlo Gilchuk ◽  
Seth J. Zost ◽  
Philipp A. Ilinykh ◽  
Elad Binshtein ◽  
...  

Understanding the human antibody response to emerging viral pathogens is key to epidemic preparedness. As the size of the B cell response to a pathogenic virus protective antigen is undefined, we performed deep paired heavy and light chain sequencing in EBOV-GP specific memory B cells, allowing analysis of the ebolavirus-specific antibody repertoire both genetically and functionally. This approach facilitated investigation of the molecular and genetic basis for evolution of cross-reactive antibodies by elucidating germline-encoded properties of antibodies to EBOV and identification of the overlap between antibodies in the memory B-cell and serum repertoire. We identified 73 public clonotypes to EBOV, 20% of which encoded antibodies with neutralization activity and capacity to protect in vivo. This comprehensive analysis of the public and private antibody repertoire provides insight into the molecular basis of the humoral immune response to EBOV-GP, which informs vaccine design of new vaccines and improved therapeutics.


Author(s):  
Taushif Khan ◽  
Mahbuba Rahman ◽  
Fatima Al Ali ◽  
Susie S. Y. Huang ◽  
Manar Ata ◽  
...  

AbstractFour endemic human coronaviruses (HCoVs) are commonly associated with acute respiratory infection in humans. B cell responses to these “common cold” viruses remain incompletely understood. Here we report a comprehensive analysis of CoV-specific antibody repertoires in 231 children and 1168 adults using phage-immunoprecipitation sequencing. Seroprevalence of antibodies to endemic HCoVs ranged between ~4 and 27% depending on the species and cohort. We identified at least 136 novel linear B cell epitopes. Antibody repertoires against endemic HCoVs were qualitatively different between children and adults in that anti-HCoV IgG specificities more frequently found among children targeted functionally important and structurally conserved regions of the spike, nucleocapsid and matrix proteins. Moreover, antibody specificities targeting the highly conserved fusion peptide region and S2’ cleavage site of the spike protein were broadly cross-reactive with peptides of epidemic human and non-human coronaviruses. In contrast, an acidic tandem repeat in the N-terminal region of the Nsp3 subdomain of the HCoV-HKU1 polyprotein was the predominant target of antibody responses in adult donors. Our findings shed light on the dominant species-specific and pan-CoV target sites of human antibody responses to coronavirus infection, thereby providing important insights for the development of prophylactic or therapeutic monoclonal antibodies and vaccine design.


2016 ◽  
Vol 113 (19) ◽  
pp. E2636-E2645 ◽  
Author(s):  
Brandon J. DeKosky ◽  
Oana I. Lungu ◽  
Daechan Park ◽  
Erik L. Johnson ◽  
Wissam Charab ◽  
...  

Elucidating how antigen exposure and selection shape the human antibody repertoire is fundamental to our understanding of B-cell immunity. We sequenced the paired heavy- and light-chain variable regions (VH and VL, respectively) from large populations of single B cells combined with computational modeling of antibody structures to evaluate sequence and structural features of human antibody repertoires at unprecedented depth. Analysis of a dataset comprising 55,000 antibody clusters from CD19+CD20+CD27− IgM-naive B cells, >120,000 antibody clusters from CD19+CD20+CD27+ antigen–experienced B cells, and >2,000 RosettaAntibody-predicted structural models across three healthy donors led to a number of key findings: (i) VH and VL gene sequences pair in a combinatorial fashion without detectable pairing restrictions at the population level; (ii) certain VH:VL gene pairs were significantly enriched or depleted in the antigen-experienced repertoire relative to the naive repertoire; (iii) antigen selection increased antibody paratope net charge and solvent-accessible surface area; and (iv) public heavy-chain third complementarity-determining region (CDR-H3) antibodies in the antigen-experienced repertoire showed signs of convergent paired light-chain genetic signatures, including shared light-chain third complementarity-determining region (CDR-L3) amino acid sequences and/or Vκ,λ–Jκ,λ genes. The data reported here address several longstanding questions regarding antibody repertoire selection and development and provide a benchmark for future repertoire-scale analyses of antibody responses to vaccination and disease.


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