scholarly journals Pandemic, epidemic, endemic: B cell repertoire analysis reveals unique anti-viral responses to SARS-CoV-2, Ebola and Respiratory Syncytial Virus

2021 ◽  
Author(s):  
Alexander Stewart ◽  
Emma Sinclair ◽  
Joseph CF Ng ◽  
Franca Fraternali ◽  
Joselli Silvia-O'Hare ◽  
...  

Immunoglobulin gene heterogeneity reflects the diversity and focus of the humoral immune response towards different infections, enabling inference of B cell development processes. Detailed compositional and lineage analysis of long read IGH repertoire sequencing, combining examples of pandemic, epidemic and endemic viral infections with control and vaccination samples, demonstrates general responses including increased use of IGHV4-39 in both EBOV and COVID-19 infection cohorts. We also show unique characteristics absent in RSV infection or yellow fever vaccine samples: EBOV survivors show unprecedented high levels of class switching events while COVID-19 repertoires from acute disease appear underdeveloped. Despite the high levels of clonal expansion in COVID-19 IgG1 repertoires there is a striking lack of evidence of germinal centre mutation and selection. Given the differences in COVID-19 morbidity and mortality with age, it is also pertinent that we find significant differences in repertoire characteristics between young and old patients. Our data supports the hypothesis that a primary viral challenge can result in a strong but immature humoral response where failures in selection of the repertoire risks off-target effects.

2000 ◽  
Vol 20 (15) ◽  
pp. 5363-5369 ◽  
Author(s):  
Klaus-Peter Knobeloch ◽  
Mark D. Wright ◽  
Adrian F. Ochsenbein ◽  
Oliver Liesenfeld ◽  
Jürgen Löhler ◽  
...  

ABSTRACT CD37 is a membrane protein of the tetraspanin superfamily, which includes CD9, CD53, CD63, CD81, and CD82. Many of these molecules are expressed on leukocytes and have been implicated in signal transduction, cell-cell interactions, and cellular activation and development. We generated and analyzed mice deficient for CD37. Despite the high expression of CD37 on cells of the immune system, no changes in development and cellular composition of lymphoid organs were observed in mice lacking CD37. Analyses of humoral immune responses revealed a reduced level of immunoglobulin G1 (IgG1) in the sera of nonimmunized mice and an alteration of responses to T-cell-dependent antigens. Antibody responses to model antigen administered in the absence of adjuvant and to viral infections were generally poor in CD37-deficient mice. These poor antibody responses could be overcome by the immunization of antigen together with adjuvant. These results suggest a role for CD37 in T-cell–B-cell interactions which manifests itself under suboptimal costimulatory conditions.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Marie Ghraichy ◽  
Valentin von Niederhäusern ◽  
Aleksandr Kovaltsuk ◽  
Jacob D Galson ◽  
Charlotte M Deane ◽  
...  

Several human B-cell subpopulations are recognized in the peripheral blood, which play distinct roles in the humoral immune response. These cells undergo developmental and maturational changes involving VDJ recombination, somatic hypermutation and class switch recombination, altogether shaping their immunoglobulin heavy chain (IgH) repertoire. Here, we sequenced the IgH repertoire of naïve, marginal zone, switched and plasma cells from 10 healthy adults along with matched unsorted and in silico separated CD19+ bulk B cells. Using advanced bioinformatic analysis and machine learning, we show that sorted B cell subpopulations are characterised by distinct repertoire characteristics on both the individual sequence and the repertoire level. Sorted subpopulations shared similar repertoire characteristics with their corresponding in silico separated subsets. Furthermore, certain IgH repertoire characteristics correlated with the position of the constant region on the IgH locus. Overall, this study provides unprecedented insight over mechanisms of B cell repertoire control in peripherally circulating B cell subpopulations.


2021 ◽  
Author(s):  
Marie Ghraichy ◽  
Valentin von Niederhäusern ◽  
Aleksandr Kovaltsuk ◽  
Jacob Daniel Galson ◽  
Charlotte M Deane ◽  
...  

Background: Several human B-cell subpopulations are recognized in the peripheral blood, which play distinct roles in the humoral immune response. These cells undergo developmental and maturational changes involving VDJ recombination, somatic hypermutation and class switch recombination, altogether shaping their immunoglobulin heavy chain (IgH) repertoire. Methods: Here, we sequenced the IgH repertoire of naïve, marginal zone, switched and plasma cells from 10 healthy adults along with matched unsorted and in silico separated CD19+ bulk B cells. We used advanced bioinformatic analysis and machine learning to thoroughly examine and compare these repertoires. Results: We show that sorted B cell subpopulations are characterised by distinct repertoire characteristics on both the individual sequence and the repertoire level. Sorted subpopulations shared similar repertoire characteristics with their corresponding in silico separated subsets. Furthermore, certain IgH repertoire characteristics correlated with the position of the constant region on the IgH locus. Conclusion: Overall, this study provides unprecedented insight over mechanisms of B cell repertoire control in peripherally circulating B cell subpopulations.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4370-4370
Author(s):  
Francesco Forconi ◽  
Kathleen N Potter ◽  
Isla Wheatley ◽  
Nikos Darzentas ◽  
Elisa Sozzi ◽  
...  

Abstract Abstract 4370 The cell of origin of chronic lymphocytic leukemia (CLL) has long been sought and immunoglobulin gene analysis provides new clues. The immunoglobulin heavy variable gene (IGHV) status has clinical relevance in CLL, where two subsets, delineated by the absence or presence of somatic mutation, have markedly different prognoses. The unmutated subset (U-CLL), of inferior prognosis, appears to derive from a pre-germinal center B cell. In U-CLL, there is strikingly increased usage of the 51p1-related alleles of the IGHV1-69 gene, often combined with selected IGHD genes and with IGHJ6. Shared sequence “stereotypic” characteristics of the HCDR3 result, and suggest antigen selection of the leukemic clones. In this study, we have analyzed 147 51p1/IGHJ6 rearrangements from 3 healthy individuals (>51yr) and sought sequence patterns parallel to those of U-CLL. A pre-established dataset of 313 51p1/IGHJ6 rearrangements from patients with U-CLL was used as a reference. A high proportion (49/147, 33.3%) of normal sequences revealed stereotypic patterns, several (22/147, 15%) being similar to those described in U-CLL. Additional CLL-associated stereotypes, not yet reported, were detected in 7/147 sequences (4.8%). Stereotypes (13.6%) not detected in CLL were also found in 20/147 (13.6%) 51p1/IGHJ6 combinations. The HCDR2-IGHJ6 sequences were almost exclusively unmutated (143/147, 97,3% sequences had ≥98% homology to germline). Junctional amino acids in normal B cells were heterogeneous, as in the cases of CLL with stereotyped 51p1/IGHJ6 B-cell receptors. Normal B cells expressing 51p1-derived IgM (4.8% of all B-cells) had a phenotype of naïve B-cells, similar to 51p1-negative (CD27-) B cells, i.e. IgM+ IgD+ CD23+ CD38+, with a small percentage of CD5+ B cells, not found in the memory B-cell subset. This snapshot of the naïve B-cell repertoire reveals subsets of B cells closely related to those characteristic of CLL. Conserved patterns in the 51p1-encoded IgM of normal B cells suggest a restricted sequence repertoire shaped by evolution to recognize common pathogens. Proliferative pressure on these cells is the likely route to U-CLL. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 17 (7) ◽  
pp. e1009708
Author(s):  
Vinit Upasani ◽  
Izabela Rodenhuis-Zybert ◽  
Tineke Cantaert

The humoral immune response and antibody-mediated functions of B cells during viral infections are well described. However, we have limited understanding of antibody-independent B cell functions, such as cytokine production and antigen presentation, in acute and chronic viral infections and their role in protection and/or immunopathogenesis. Here, we summarize the current literature on these antibody-independent B cell functions and identify remaining knowledge gaps. B cell subsets produce anti- and pro-inflammatory cytokines, which can have both beneficial and detrimental effects during viral clearance. As professional antigen presenting cells, B cells also play an important role in immune regulation/shaping of the developing adaptive immune responses. Since B cells primarily express TLR7 and TLR9, we specifically discuss the role of Toll-like receptor (TLR)-mediated B cell responses to viral infections and their role in augmenting adaptive immunity through enhanced cytokine production and antigen presentation. However, viruses have evolved strategies to subvert TLR signaling and additional stimulation via B cell receptor (BCR) may be required to overcome the defective TLR response in B cells. To conclude, antibody-independent B cell functions seem to have an important role in regulating both acute and chronic viral infections and may form the basis for novel therapeutic approaches in treatment of viral infections in the future.


2019 ◽  
Author(s):  
Liam Kealy ◽  
Andrea Di Pietro ◽  
Lauren Hailes ◽  
Sebastian Scheer ◽  
Lennard Dalit ◽  
...  

SUMMARYHistone modifiers are essential molecular regulators that underpin the ability of immune cells to reprogram their gene expression during differentiation. The recruitment of the histone methyltransferase DOT1L induces oncogenic gene expression in a subset of B cell leukemia. Despite its importance, little is known about its role in the humoral immune system. Herein, we demonstrate that DOT1L is a critical regulator of B cell biology. Dot1lf/fMb1Cre/+ mice had a block in B cell development, culminating in a significant reduction of mature B cells in the periphery. Upon immunization or influenza infection of Dot1lf/fCd23Cre/+ mice, germinal centers failed to form and class-switched antibody-secreting cells were significantly attenuated. Consequently, immunized mice revealed that DOT1L was essential for the formation of B cell memory populations. Transcriptome, pathway and histological analysis identified a key role for DOT1L in reprogramming gene expression for migration and localization during the initial stages of a humoral response. Together, these results demonstrate an essential role for DOT1L in antigen-dependent B cell differentiation and hence, in generating an effective and lasting humoral immune response.


2021 ◽  
Author(s):  
Jillian M. DiMuzio ◽  
Baron C. Heimbach ◽  
Raymond J. Howanski ◽  
John P. Dowling ◽  
Nirja B. Patel ◽  
...  

AbstractPatients who recover from SARS-CoV-2 infections produce antibodies and antigen-specific T cells against multiple viral proteins. Here, an unbiased interrogation of the anti-viral memory B cell repertoire of convalescent patients has been performed by generating large, stable hybridoma libraries and screening thousands of monoclonal antibodies to identify specific, high-affinity immunoglobulins (Igs) directed at distinct viral components. As expected, a significant number of antibodies were directed at the Spike (S) protein, a majority of which recognized the full-length protein. These full-length Spike specific antibodies included a group of somatically hypermutated IgMs. Further, all but one of the six COVID-19 convalescent patients produced class-switched antibodies to a soluble form of the receptor-binding domain (RBD) of S protein. Functional properties of anti-Spike antibodies were confirmed in a pseudovirus neutralization assay. Importantly, more than half of all of the antibodies generated were directed at non-S viral proteins, including structural nucleocapsid (N) and membrane (M) proteins, as well as auxiliary open reading frame-encoded (ORF) proteins. The antibodies were generally characterized as having variable levels of somatic hypermutations (SHM) in all Ig classes and sub-types, and a diversity of VL and VH gene usage. These findings demonstrated that an unbiased, function-based approach towards interrogating the COVID-19 patient memory B cell response may have distinct advantages relative to genomics-based approaches when identifying highly effective anti-viral antibodies directed at SARS-CoV-2.


Blood ◽  
2010 ◽  
Vol 115 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Francesco Forconi ◽  
Kathleen N. Potter ◽  
Isla Wheatley ◽  
Nikos Darzentas ◽  
Elisa Sozzi ◽  
...  

Abstract The cell of origin of chronic lymphocytic leukemia (CLL) has long been sought, and immunoglobulin gene analysis provides new clues. In the unmutated subset (U-CLL), there is increased usage of the 51p1-related alleles of the immunoglobulin heavy chain variable 1-69 gene, often combined with selected genes and with immunoglobulin heavy chain diversity IGHJ6. Stereotypic characteristics of the HCDR3 result and suggest antigen selection of the leukemic clones. We have now analyzed 51p1/IGHJ6 combinations in normal blood B cells from 3 healthy persons for parallel sequence patterns. A high proportion (33.3% of sequences) revealed stereotypic patterns, with several (15.0%) being similar to those described in U-CLL. Previously unreported CLL-associated stereotypes were detected in 4.8%. Stereotypes (13.6%) not detected in CLL also were found. The HCDR2-IGHJ6 sequences were essentially unmutated. Junctional amino acids in normal B cells were heterogeneous, as in cases of stereotyped CLL. Phenotypically, normal B cells expressing 51p1-derived immunoglobulin M were naive. This snapshot of the naive B-cell repertoire reveals subsets of B cells closely related to those characteristic of CLL. Conserved patterns in the 51p1-encoded immunoglobulin M of normal B cells suggest a restricted sequence repertoire shaped by evolution to recognize common pathogens. Proliferative pressure on these cells is the likely route to U-CLL.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Nancy Chaaya ◽  
Melody A. Shahsavarian ◽  
Irene Maffucci ◽  
Alain Friboulet ◽  
Bernard Offmann ◽  
...  

Abstract The relationship between the immune repertoire and the physiopathological status of individuals is essential to apprehend the genesis and the evolution of numerous pathologies. Nevertheless, the methodological approaches to understand these complex interactions are challenging. We performed a study evaluating the diversity harbored by different immune repertoires as a function of their physiopathological status. In this study, we base our analysis on a murine scFv library previously described and representing four different immune repertoires: i) healthy and naïve, ii) healthy and immunized, iii) autoimmune prone and naïve, and iv) autoimmune prone and immunized. This library, 2.6 × 109 in size, is submitted to high throughput sequencing (Next Generation Sequencing, NGS) in order to analyze the gene subgroups encoding for immunoglobulins. A comparative study of the distribution of immunoglobulin gene subgroups present in the four libraries has revealed shifts in the B cell repertoire originating from differences in genetic background and immunological status of mice.


1992 ◽  
Vol 175 (4) ◽  
pp. 983-991 ◽  
Author(s):  
T Martin ◽  
S F Duffy ◽  
D A Carson ◽  
T J Kipps

Natural autoantibodies are primarily immunoglobulin M (IgM) antibodies that bind to a variety of self-antigens, including self-IgG. Accounting for a large proportion of the early B cell repertoire, such polyspecific autoantibodies are speculated to contribute to the homeostasis and/or competence of the primary humoral immune system. Recent studies indicate that the leukemia cells from most patients with chronic lymphocytic leukemia (CLL) also express such IgM autoantibodies. Similarly, the leukemia cells from many CLL patients react with murine monoclonal antibodies (mAbs) specific for crossreactive idiotypes (CRIs) associated with human IgM autoantibodies. In particular, leukemic cells frequently react with G6, a mAb specific for an Ig heavy chain (H chain)-associated CRI, and/or with 17.109, a mAb that defines a kappa light chain (L chain)-associated CRI. Generated against IgM rheumatoid factor (RF) paraproteins, G6 and 17.109 each recognize a major CRI that is present in many IgM RF paraproteins. Furthermore, over 90% of the IgM paraproteins found to bear both H and L chain-associated CRIs also are found to have RF activity. Molecular characterization of these CRIs demonstrates that each is a serologic marker for expression of a highly conserved Ig V gene. As such, the frequent production of IgM polyspecific autoantibodies in CLL simply may reflect the frequent use of such highly conserved autoantibody-encoding Ig V genes with little or no somatic mutation. To test this hypothesis, we generated murine transfectomas to pair the 17.109-reactive kappa L chain of SMI, a 17.109/G6-reactive CLL population, with the Ig H chain of SMI or other G6-reactive leukemia cells or tonsillar lymphocytes. Cotransfection of vectors encoding the Ig H and L chains of SMI generated transfectomas that produce IgM kappa RF autoantibodies reactive with human IgG1 and IgG4. In contrast to G6/17.109-reactive IgM kappa RF Waldenstrom's paraproteins, the SMI IgM kappa also reacts with several other self-antigens, including myoglobin, actin, and ssDNA. However, cotransfection of the SMI L chain with a vector encoding any one of 10 different G6-reactive Ig H chains generated transfectomas that produce IgM kappa antibodies without detectable polyspecific autoantibody activity. These results indicate that polyspecific antiself-reactivity of G6/17.019-reactive Ig is dependent on the somatically generated Ig third complementarity determining region. Collectively, these studies imply that selection may be responsible for the frequent expression of polyspecific autoantibodies in CLL and early B cell ontogeny.


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