Institut für Medizintechnik und Medizininformatik

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  • Publikation
    Maturation of the human B-cell receptor repertoire with age
    (Cold Spring Harbor Laboratory, 20.12.2019) Ghraichy, Marie; Galson, Jacob D.; Kovaltsuk, Aleksandr; Niederhäusern, Valentin von; Schmid, Jana Pachlopnik; Recher, Mike; Jauch, Annaïse J; Miho, Enkelejda; Kelly, Dominic F.; Deane, Charlotte M.; Trück, Johannes [in: bioRxiv]
    B cells play a central role in adaptive immune processes, mainly through the production of antibodies. The maturation of the B-cell system with age is poorly studied. We extensively investigated age-related alterations of naïve and antigen-experienced B-cell receptor (BCR) repertoires. The most significant changes were observed in the first 10 years of life, and were characterized by altered immunoglobulin gene usage and an increased frequency of mutated antibodies structurally diverging from their germline precursors. Older age was associated with an increased usage of downstream constant region genes and fewer antibodies with self-reactive properties. As mutations accumulated with age, the frequency of germline-encoded self-reactive antibodies decreased, indicating a possible beneficial role of self-reactive B-cells in the developing immune system. Our results suggest a continuous process of change through childhood across a broad range of parameters characterizing BCR repertoires and stress the importance of using well-selected, age-appropriate controls in BCR studies
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publikation
    Comparison of methods for phylogenetic B-cell lineage inference using time-resolved antibody repertoire simulations (AbSim)
    (Oxford University Press, 31.08.2017) Yermanos, Alexander; Greiff, Victor; Krautler, Nike Julia; Menzel, Ulrike; Dounas, Andreas; Miho, Enkelejda; Oxenius, Annette; Stadler, Tanja; Reddy, Sai T.; Kelso, Janet [in: Bioinformatics]
    Motivation: The evolution of antibody repertoires represents a hallmark feature of adaptive B-cell immunity. Recent advancements in high-throughput sequencing have dramatically increased the resolution to which we can measure the molecular diversity of antibody repertoires, thereby offering for the first time the possibility to capture the antigen-driven evolution of B cells. However, there does not exist a repertoire simulation framework yet that enables the comparison of com monly utilized phylogenetic methods with regard to their accuracy in inferring antibody evolution.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publikation
    Learning the high-dimensional immunogenomic features that predict public and private antibody repertoires
    (American Association of Immunologists, 15.10.2017) Greiff, Victor; Weber, Cédric R.; Palme, Johannes; Bodenhofer, Ulrich; Miho, Enkelejda; Menzel, Ulrike; Reddy, Sai T. [in: Journal of Immunology]
    Recent studies have revealed that immune repertoires contain a substantial fraction of public clones, which may be defined as Ab or TCR clonal sequences shared across individuals. It has remained unclear whether public clones possess predictable sequence features that differentiate them from private clones, which are believed to be generated largely stochastically. This knowledge gap represents a lack of insight into the shaping of immune repertoire diversity. Leveraging a machine learning approach capable of capturing the high-dimensional compositional information of each clonal sequence (defined by CDR3), we detected predictive public clone and private clone–specific immunogenomic differences concentrated in CDR3’s N1–D–N2 region, which allowed the prediction of public and private status with 80% accuracy in humans and mice. Our results unexpectedly demonstrate that public, as well as private, clones possess predictable high-dimensional immunogenomic features. Our support vector machine model could be trained effectively on large published datasets (3 million clonal sequences) and was sufficiently robust for public clone prediction across individuals and studies prepared with different library preparation and high-throughput sequencing protocols. In summary, we have uncovered the existence of high-dimensional immunogenomic rules that shape immune repertoire diversity in a predictable fashion. Our approach may pave the way for the construction of a comprehensive atlas of public mouse and human immune repertoires with potential applications in rational vaccine design and immunotherapeutics.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publikation
    Synthetic standards combined with error and bias correction improve the accuracy and quantitative resolution of antibody repertoire sequencing in human naïve and memory B cells
    (Frontiers Research Foundation, 20.06.2018) Friedensohn, Simon; Lindner, John M.; Cornacchione, Vanessa; Iazeolla, Mariavittoria; Miho, Enkelejda; Zingg, Andreas; Meng, Simon; Traggiai, Elisabetta; Reddy, Sai T. [in: Frontiers in Immunology]
    High-throughput sequencing of immunoglobulin (Ig) repertoires (Ig-seq) is a powerful method for quantitatively interrogating B cell receptor sequence diversity. When applied to human repertoires, Ig-seq provides insight into fundamental immunological questions, and can be implemented in diagnostic and drug discovery projects. However, a major challenge in Ig-seq is ensuring accuracy, as library preparation protocols and sequencing platforms can introduce substantial errors and bias that compromise immunological interpretation. Here, we have established an approach for performing highly accurate human Ig-seq by combining synthetic standards with a comprehensive error and bias correction pipeline. First, we designed a set of 85 synthetic antibody heavy-chain standards (in vitro transcribed RNA) to assess correction workflow fidelity. Next, we adapted a library preparation protocol that incorporates unique molecular identifiers (UIDs) for error and bias correction which, when applied to the synthetic standards, resulted in highly accurate data. Finally, we performed Ig-seq on purified human circulating B cell subsets (naïve and memory), combined with a cellular replicate sampling strategy. This strategy enabled robust and reliable estimation of key repertoire features such as clonotype diversity, germline segment, and isotype subclass usage, and somatic hypermutation. We anticipate that our standards and error and bias correction pipeline will become a valuable tool for researchers to validate and improve accuracy in human Ig-seq studies, thus leading to potentially new insights and applications in human antibody repertoire profiling.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publikation
    High-throughput sequencing of human immunoglobulin variable regions with subtype identification
    (Public Library of Science, 03.11.2014) Schanz, Merle; Liechti, Thomas; Zagordi, Osvaldo; Miho, Enkelejda; Reddy, Sai T.; Günthard, Huldrych F.; Trkola, Alexandra; Huber, Michael; Lu, Shan [in: PLOS ONE]
    The humoral immune response plays a critical role in controlling infection, and the rapid adaptation to a broad range of pathogens depends on a highly diverse antibody repertoire. The advent of high-throughput sequencing technologies in the past decade has enabled insights into this immense diversity. However, not only the variable, but also the constant region of antibodies determines their in vivo activity. Antibody isotypes differ in effector functions and are thought to play a defining role in elicitation of immune responses, both in natural infection and in vaccination. We have developed an Illumina MiSeq high-throughput sequencing protocol that allows determination of the human IgG subtype alongside sequencing full-length antibody variable heavy chain regions. We thereby took advantage of the Illumina procedure containing two additional short reads as identifiers. By performing paired-end sequencing of the variable regions and customizing one of the identifier sequences to distinguish IgG subtypes, IgG transcripts with linked information of variable regions and IgG subtype can be retrieved. We applied our new method to the analysis of the IgG variable region repertoire from PBMC of an HIV-1 infected individual confirmed to have serum antibody reactivity to the Membrane Proximal External Region (MPER) of gp41. We found that IgG3 subtype frequencies in the memory B cell compartment increased after halted treatment and coincided with increased plasma antibody reactivity against the MPER domain. The sequencing strategy we developed is not restricted to analysis of IgG. It can be adopted for any Ig subtyping and beyond that for any research question where phasing of distant regions on the same amplicon is needed.
    01A - Beitrag in wissenschaftlicher Zeitschrift