| 1. |
- Corcoran, Martin M., et al.
(författare)
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Production of individualized V gene databases reveals high levels of immunoglobulin genetic diversity
- 2016
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Ingår i: nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Comprehensive knowledge of immunoglobulin genetics is required to advance our understanding of B cell biology. Validated immunoglobulin variable (V) gene databases are close to completion only for human and mouse. We present a novel computational approach, IgDiscover, that identifies germline V genes from expressed repertoires to a specificity of 100%. IgDiscover uses a cluster identification process to produce candidate sequences that, once filtered, results in individualized germline V gene databases. IgDiscover was tested in multiple species, validated by genomic cloning and cross library comparisons and produces comprehensive gene databases even where limited genomic sequence is available. IgDiscover analysis of the allelic content of the Indian and Chinese-origin rhesus macaques reveals high levels of immunoglobulin gene diversity in this species. Further, we describe a novel human IGHV3-21 allele and confirm significant gene differences between Balb/c and C57BL6 mouse strains, demonstrating the power of IgDiscover as a germline V gene discovery tool.
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| 2. |
- Phad, Ganesh E., et al.
(författare)
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Extensive dissemination and intraclonal maturation of HIV Env vaccine-induced B cell responses
- 2020
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Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 217:2
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Tidskriftsartikel (refereegranskat)abstract
- Well-ordered HIV-1 envelope glycoprotein (Env) trimers are prioritized for clinical evaluation, and there is a need for an improved understanding about how elicited B cell responses evolve following immunization. To accomplish this, we prime-boosted rhesus macaques with Glade C NFL trimers and identified 180 unique Ab lineages from similar to 1,000 single-sorted Envspecific memory B cells. We traced all lineages in high-throughput heavy chain (HC) repertoire (Rep-seq) data generated from multiple immune compartments and time points and expressed several as monoclonal Abs (mAbs). Our results revealed broad dissemination and high levels of somatic hypermutation (SHM) of most lineages, including tier 2 virus neutralizing lineages, following boosting. SHM was highest in the Ab complementarity determining regions (CDRs) but also surprisingly high in the framework regions (FRO, especially FR3. Our results demonstrate the capacity of the immune system to affinity-mature large numbers of Env-specific B cell lineages simultaneously, supporting the use of regimens consisting of repeated boosts to improve each Ab, even those belonging to less expanded lineages.
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| 3. |
- Vázquez Bernat, Néstor
(författare)
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Definition of immunoglobulin germline genes by next generation sequencing for studies of antigen-specific B cell responses
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Immunoglobulins play a critical role in the adaptive immune system, existing as cell surface-expressed B cell receptors and secreted antibodies. Circulating antibodies are the main correlate of protective immunity for most vaccines. An improved understanding of the germline genes that rearrange to encode the vast repertoire of antibodies is therefore of central interest. Despite this, current databases of immunoglobulin germline gene variation are incomplete, both for humans and research animal models, limiting studies of antigen-specific B cell responses. In Paper I, we developed a computational tool, IgDiscover, which infers germline immunoglobulin V alleles from the repertoire of expressed antibodies in a given individual. We validated IgDiscover for the identification of human, mouse and rhesus macaque IGHV alleles and described novel IGHV alleles in all three species. Our results highlighted a high degree of inter-individual allelic diversity in rhesus macaques. In Paper II, we optimized and compared two major immunoglobulin library production methods based on 5′RACE and 5′multiplex PCR, respectively. We observed that, despite 5′RACE being unbiased in terms of amplification and having the advantage of not requiring 5′ end IGHV genomic information, current limitations on high-throughput sequence read length resulted in the 5′ multiplex method delivering a higher quality output due to its shorter amplicon size. In Paper III, we inferred germline immunoglobulin alleles in 45 macaques from four sub-populations of the two most common species used in biomedical research, rhesus and cynomolgus macaques. We confirmed and extended our observations concerning high inter-individual diversity, demonstrating that it was highest among Indonesian cynomolgus macaques and lowest among Mauritian cynomolgus macaques in the sub-populations studied. We compiled comprehensive IGHV, D and J allele databases and used several methods to independently validate novel alleles. In conclusion, the work presented in this thesis establishes a road map to generate individualized immunoglobulin germline gene databases from diverse species, even if genomic immunoglobulin loci information is limited. This thesis also examines the advantages and disadvantages of commonly used next generation sequencing library preparation methods. Finally, it reports novel inferred immunoglobulin alleles in humans and macaques and illustrates a high degree of inter-individual immunoglobulin allelic diversity in primates, underlining the utility of generating individualized immunoglobulin databases for studies of immune repertoires.
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