Testing the role of B cell receptor signalling in germinal centre responses
Lead Research Organisation:
University of Birmingham
Department Name: Immunity and Infection
Abstract
In our highly mobile society the risks from infectious diseases are increasing due to increased travel, altered global migration and reduced security in the food-chain. Vaccination is a cost-effective approach that can protect against infection. However, vaccination does not always guarantee complete protection against infection and this is especially true in the very young and the elderly. As longevity is increasing, by 2034 it is estimated that 1 in 4 of the UK population will be aged over 65, this issue will continue to be at the forefront of preventive medicine. One of the main reasons for reduced vaccination responses is that the immune system is impaired at the extremes of age. Although poorly understood one cause is poor functioning of B cells, the immune cells that produce the antibodies that help identify and remove pathogens and thus prevent infection.
Production of long lived pathogen-specific B cells is the basis of most vaccinations. When a new pathogen or vaccine enters the body B cells respond by producing antibody and importantly they are conditioned through an optimization process called "affinity maturation" to continually try to improve the quality of the antibody they make. The process is akin to evolution in that B cells undergo repeated rounds of antibody gene mutation followed by selection of the "fittest" B cells to produce antibody that will best deal with the pathogen. How affinity maturation works has been under intense scrutiny over recent years and we know that it involves B cells receiving help from other immune cell, namely T cells. What we do not understand is how the direct interaction of B cells with the pathogen or vaccine shapes this process and having this missing piece of information should allow us to develop radically different approaches to vaccinations to improve the quantity and quality of antibody produced for example in older adults.
The ultimate aim of this project is to understand how this B cell and antibody selection process is regulated to allow us to produce better vaccines. This will be achieved through collaboration with the company Medimmune who will help to produce genetically modified mice where affinity maturation is enhanced. In addition to helping develop better vaccines, these mice will become valuable tools for industry in the quest to produce new monoclonal antibody therapeutics, as the process of generating new monoclonal antibodies itself involves vaccination.
The link with Medimmune will ensure that their capacity in animal model generation is integrated with Dr Toellner's knowledge of B cell and vaccination biology, to produce a project that will lead to a step change in the field and generate resources useful to researchers and industry alike.
Production of long lived pathogen-specific B cells is the basis of most vaccinations. When a new pathogen or vaccine enters the body B cells respond by producing antibody and importantly they are conditioned through an optimization process called "affinity maturation" to continually try to improve the quality of the antibody they make. The process is akin to evolution in that B cells undergo repeated rounds of antibody gene mutation followed by selection of the "fittest" B cells to produce antibody that will best deal with the pathogen. How affinity maturation works has been under intense scrutiny over recent years and we know that it involves B cells receiving help from other immune cell, namely T cells. What we do not understand is how the direct interaction of B cells with the pathogen or vaccine shapes this process and having this missing piece of information should allow us to develop radically different approaches to vaccinations to improve the quantity and quality of antibody produced for example in older adults.
The ultimate aim of this project is to understand how this B cell and antibody selection process is regulated to allow us to produce better vaccines. This will be achieved through collaboration with the company Medimmune who will help to produce genetically modified mice where affinity maturation is enhanced. In addition to helping develop better vaccines, these mice will become valuable tools for industry in the quest to produce new monoclonal antibody therapeutics, as the process of generating new monoclonal antibodies itself involves vaccination.
The link with Medimmune will ensure that their capacity in animal model generation is integrated with Dr Toellner's knowledge of B cell and vaccination biology, to produce a project that will lead to a step change in the field and generate resources useful to researchers and industry alike.
Technical Summary
B cell activation leading to B cell differentiation is regulated by two major signals: Signals through B cell receptors (BCR) and signals from T helper cells. These signals regulate antibody responses during initial B cell activation after antigen entry, during the evolution to high affinity in germinal centres, and during the reactivation of a memory response. While signals from T cells are well studied, there is less information about the impact of differential BCR signals on B cell activation.
We will test the hypothesis that BCR signal strength is an important regulator of B cell differentiation. To test this, a range of mouse models with altered BCR signalling strength are developed. These involve hybrids of B cell receptors of naive B cells (IgM or IgD) and IgG1, leading to mice with hyperactive signalling in naïve B cells, and inducible mutations of kinases or phosphatases downstream of BCR signalling. These models will allow induction of differentiation stage dependent variation of BCR signalling strength in vivo, allowing us to comprehensively test the role of BCR signalling during differentiation stages in response to vaccination and B cell selection and differentiation. Importantly, all models proposed will lead to changes in BCR signalling activity when B cells enter the germinal centres. Therefore, we will be able to test whether and how BCR signalling strength within the germinal centre regulates B cell selection.
A spin-off from this project will be new mouse models that are more prone to produce high quality antibody responses to difficult targets, e.g. evolutionary conserved antigens or autoantigens. These may have commercial value in the production pipeline to new monoclonal antibody drugs, but will also be provided to the scientific community for non-commercial applications. The mice will also be useful to study the development of antibody mediated autoimmune diseases, and we started discussions with Rheumatologists at UoB about this.
We will test the hypothesis that BCR signal strength is an important regulator of B cell differentiation. To test this, a range of mouse models with altered BCR signalling strength are developed. These involve hybrids of B cell receptors of naive B cells (IgM or IgD) and IgG1, leading to mice with hyperactive signalling in naïve B cells, and inducible mutations of kinases or phosphatases downstream of BCR signalling. These models will allow induction of differentiation stage dependent variation of BCR signalling strength in vivo, allowing us to comprehensively test the role of BCR signalling during differentiation stages in response to vaccination and B cell selection and differentiation. Importantly, all models proposed will lead to changes in BCR signalling activity when B cells enter the germinal centres. Therefore, we will be able to test whether and how BCR signalling strength within the germinal centre regulates B cell selection.
A spin-off from this project will be new mouse models that are more prone to produce high quality antibody responses to difficult targets, e.g. evolutionary conserved antigens or autoantigens. These may have commercial value in the production pipeline to new monoclonal antibody drugs, but will also be provided to the scientific community for non-commercial applications. The mice will also be useful to study the development of antibody mediated autoimmune diseases, and we started discussions with Rheumatologists at UoB about this.
Planned Impact
Society
The importance of this work extends significantly beyond supporting academic research. By understanding how antibody responses develop we are helping to understand how to improve vaccine development. This is vital. In our highly mobile society the risks from infectious diseases are increasing due to increased travel and altered global migration and extend also into the food-chain. This is because many of our infections are actively acquired from food (e.g. Salmonella) or livestock rearing acts as an incubator and enables pathogen diversity (e.g. influenza virus). In parallel, we have a decreasing efficacy of anti-microbial treatments due to resistance and only a modest number of anti-virals available. Vaccination is a cost-effective approach that can protect against infection at the extremes of age in those groups that are most susceptible. Furthermore, vaccination is an acceptable intervention to society at large, and as the media response to the recent measles outbreak demonstrates, is one that is diminishing in controversy. Indeed, the measles outbreak demonstrates the importance of vaccination programmes to protecting society and the consequences when there is insufficient vaccine coverage. Theoretical background how vaccines work, what signals regulate the emergence of high affinity B cells and antibody producing cells, and how immunological memory cells are regulated, is still in its infancy.
Industry
This collaboration between industry and UoB will not only increase our theoretical understanding of immune responses to vaccines, which may lead to better intelligent design of vaccines. It also will produce valuable information and tools (mouse strains) for the production pipeline towards new monoclonal antibody therapeutics. Generation of monoclonal antibody drugs to new targets involves vaccination of mice as a first step of raising specific antibodies. Understanding the immunological principles of vaccination will help designing and choosing antigens reliably inducing immune responses. Further, we expect the new mouse strains produced to produce antibody responses to difficult targets, e.g. autoantigens or conserved antigens that are of superior quality, i.e. broadness of the response to different antigenic epitopes and affinity of antibodies developing.
The importance of this work extends significantly beyond supporting academic research. By understanding how antibody responses develop we are helping to understand how to improve vaccine development. This is vital. In our highly mobile society the risks from infectious diseases are increasing due to increased travel and altered global migration and extend also into the food-chain. This is because many of our infections are actively acquired from food (e.g. Salmonella) or livestock rearing acts as an incubator and enables pathogen diversity (e.g. influenza virus). In parallel, we have a decreasing efficacy of anti-microbial treatments due to resistance and only a modest number of anti-virals available. Vaccination is a cost-effective approach that can protect against infection at the extremes of age in those groups that are most susceptible. Furthermore, vaccination is an acceptable intervention to society at large, and as the media response to the recent measles outbreak demonstrates, is one that is diminishing in controversy. Indeed, the measles outbreak demonstrates the importance of vaccination programmes to protecting society and the consequences when there is insufficient vaccine coverage. Theoretical background how vaccines work, what signals regulate the emergence of high affinity B cells and antibody producing cells, and how immunological memory cells are regulated, is still in its infancy.
Industry
This collaboration between industry and UoB will not only increase our theoretical understanding of immune responses to vaccines, which may lead to better intelligent design of vaccines. It also will produce valuable information and tools (mouse strains) for the production pipeline towards new monoclonal antibody therapeutics. Generation of monoclonal antibody drugs to new targets involves vaccination of mice as a first step of raising specific antibodies. Understanding the immunological principles of vaccination will help designing and choosing antigens reliably inducing immune responses. Further, we expect the new mouse strains produced to produce antibody responses to difficult targets, e.g. autoantigens or conserved antigens that are of superior quality, i.e. broadness of the response to different antigenic epitopes and affinity of antibodies developing.
Organisations
- University of Birmingham (Lead Research Organisation)
- AstraZeneca (Collaboration)
- Francis Crick Institute (Collaboration)
- University of Ulm (Collaboration)
- RIKEN (Collaboration)
- Leibniz Association (Collaboration)
- Albert Ludwig University of Freiburg (Collaboration)
- Alloy Therapeutics (Collaboration)
- UNIVERSITY OF CAMBRIDGE (Collaboration)
- Helmholtz Association of German Research Centres (Collaboration)
- AstraZeneca (United Kingdom) (Project Partner)
Publications
Jennings E
(2020)
Nr4a1 and Nr4a3 Reporter Mice Are Differentially Sensitive to T Cell Receptor Signal Strength and Duration.
in Cell reports
Bénézech C
(2015)
Inflammation-induced formation of fat-associated lymphoid clusters.
in Nature immunology
Barone F
(2015)
IL-22 regulates lymphoid chemokine production and assembly of tertiary lymphoid organs.
in Proceedings of the National Academy of Sciences of the United States of America
Zhang Y
(2017)
IgG1 Is Required for Optimal Protection after Immunization with the Purified Porin OmpD from Salmonella Typhimurium.
in Journal of immunology (Baltimore, Md. : 1950)
Zhang Y
(2022)
Germinal center derived B cell memory without T cells.
in The Journal of experimental medicine
Yam-Puc JC
(2021)
Enhanced BCR signaling inflicts early plasmablast and germinal center B cell death.
in iScience
Zhang Y
(2017)
Detecting Gene Expression in Lymphoid Microenvironments by Laser Microdissection and Quantitative RT-PCR.
in Methods in molecular biology (Clifton, N.J.)
Roco JA
(2019)
Class-Switch Recombination Occurs Infrequently in Germinal Centers.
in Immunity
Description | We have developed a new mouse model for B cell anergy. B cells are the cells that make antibody. Antibodies protect us from infection after vaccination. Antibodies are used as drugs to target specific antigens causing disease, e.g. antigens on tumours. Antibodies can cause disease in antibody-mediated autoimmunity. Anergic B cells are cells that cross react with self-antigens, and therefor are driven into a suppressed (anergic) activation state during B cell development. These cells continue to circulate through the body, but cannot easily be activated. Our new mouse model of B cell anergy should be useful to study the induction of autoimmunity by studying how anergy can be broken. It should also help understanding how we can overcome anergy during monoclonal antibody drug development, where it is often necessary to activate anergic B cells. |
Exploitation Route | We plan to use the new mouse model to further study anergy, autoimmunity, monoclonal antibody drug design and the response of B cells to autoantigens in cancer. |
Sectors | Manufacturing including Industrial Biotechology Pharmaceuticals and Medical Biotechnology |
Title | GM mouse strains wth altered B cell receptor signalling in germinal centres |
Description | GM mouse lines that should have altered B cell affinity maturation upon immunisation have been produced. The suitability of those to produce antibody of increased affinity is currently tested. |
Type Of Material | Model of mechanisms or symptoms - mammalian in vivo |
Provided To Others? | No |
Impact | none yet |
Title | IgMg1 mice |
Description | B cell receptor signalling was altered by adding the IgG1 signalling chain onto IgM. |
Type Of Material | Model of mechanisms or symptoms - mammalian in vivo |
Year Produced | 2018 |
Provided To Others? | No |
Impact | The new strain is a model of B cell anergy and will be useful to study autoimmunity and activation of B cells self-specific responses |
Description | An anergic B cell model for antibody discovery |
Organisation | Alloy Therapeutics |
Country | United States |
Sector | Private |
PI Contribution | We developed and characterised a new mouse strain (IgMg1 mouse) with hyperactive B cell receptor signalling, leading to general B cell anergy. We plan to test whether this model is suitable for antibody discovery. |
Collaborator Contribution | Hosting an BBSRC iCASE student to test the model using antigens used in industry, and access to lab facilities, e.g. 10x genomics. |
Impact | None yet. Industry collaboration. |
Start Year | 2020 |
Description | Gene expression in anergic B cells |
Organisation | Francis Crick Institute |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | We developed a new mouse model of B cell anergy. B cells derived from these mice are tested for gene expression by RNAseq |
Collaborator Contribution | The partner analysed gene expression by RNAseq |
Impact | no outputs yet |
Start Year | 2019 |
Description | Gene expression in memory B cells |
Organisation | Francis Crick Institute |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Provision of mRNA from in vivo differentiated memory B cells |
Collaborator Contribution | Gene expression analysis from different in vivo differentiated memory B cells by RNAseq and bioinformatic analysis |
Impact | New data on gene expression in new memory B cell subsets. |
Start Year | 2015 |
Description | In silico modelling of germinal centres |
Organisation | Helmholtz Association of German Research Centres |
Department | Helmholtz Centre for Infection Research (HZI) |
Country | Germany |
Sector | Academic/University |
PI Contribution | Data provision for in silico models Work on the in silico model |
Collaborator Contribution | In silico modelling Predictions for optimal experimental in vivo setups |
Impact | The collaboration has led to several publications. It has produced a new in silico model to analyse the regulation of affinity maturation in germinal centres. This has lead to several further collaborations and publications for our collaborators. |
Start Year | 2006 |
Description | Industrial partnership |
Organisation | AstraZeneca |
Department | MedImmune |
Country | United Kingdom |
Sector | Private |
PI Contribution | We are analysing GM mouse strains with altered B cell receptor signalling in germinal centres for their suitability as tools to produce new therapeutic monoclonal antibody drugs. The prediction is that the GM mice will easier produce specific high affinity antibodies to difficult target antigens. Further, we are analysing effects of these genetic modification on the regulation of high affinity antibody responses. |
Collaborator Contribution | The industrial partners design and produce the initial vectors for genetic manipulation of mice. They transfect these into embryonic stem cells and produce GM mice. After this step the mice are transferred to us. At a later stage they will test the mice for practical usability as vehicles to produce high affinity B cells to difficult targets for hybridoma fusions. They will use the mice and test whether they ca produce monoclonal antibodies using some of there identified human therapeutic targets. |
Impact | Three GM mouse strains have been produced and are currently analysed in our lab, publications in preparation. New iCASE PhD studentship to work on 4th strain. |
Start Year | 2014 |
Description | Intravital imaging of memory B cell migration |
Organisation | University of Cambridge |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Provision of GMO mice, |
Collaborator Contribution | Immunisation of GMO mice and intravital imaging of migrating memory B cells. Training visits for UoB staff on intravital microscopy in preparation. |
Impact | Early results show new patterns of memory B cell migration and roles of chemokine receptors directing this. |
Start Year | 2016 |
Description | Intravital imaging of plasma cell differentiation |
Organisation | Leibniz Association |
Department | German Rheumatism Research Centre |
Country | Germany |
Sector | Charity/Non Profit |
PI Contribution | A postdoctoral research fellow spent twice 2 months at DRFZ to learn intravital imaging techniques and study plasma cell differentiation from germinal centres |
Collaborator Contribution | Hosting, training, and help with experiments. Provision of experimental animals |
Impact | Training of postdoctoral research fellow Preliminary data on plasma cell differentiation Submission of funding proposal to Wellcome Trust for an intravital microscope |
Start Year | 2011 |
Description | Provision of GM mice |
Organisation | RIKEN |
Department | RIKEN Center for Integrative Medical Sciences (IMS) |
Country | Japan |
Sector | Private |
PI Contribution | Provision of mice that can be used to track germinal centre B cells |
Collaborator Contribution | Provision of mice that have an inducible expression of Cre recombinase under the control of the S1PR2 promotor |
Impact | We currently use these mice to generate new unique mouse models to study germinal centre B cell differentiation. |
Start Year | 2018 |
Description | Provision of mice with anergic B cell |
Organisation | University of Ulm |
Country | Germany |
Sector | Academic/University |
PI Contribution | This is to support our ongoing collaboration with University Freiburg, Kathrin Klaesner, Michael Reth to study B cell receptor signalling the anergic IgMg1 anergic B cell mouse, that was generated and characterised by us. |
Collaborator Contribution | Transgenic mice with anergic B cells (HEL-anti HEL system) are provided as controls for ongoing collaboration with University Freiburg, Kathrin Klaesner, Michael Reth, to study B cell receptor signalling in our IgMg1 anergic B cells |
Impact | Data on the role for B cell receptor signalling for anergy and B cell tolerance |
Start Year | 2020 |
Description | Testing the role of the cytoplasmic domain for B cell receptor signalling in vitro |
Organisation | Albert Ludwig University of Freiburg |
Country | Germany |
Sector | Academic/University |
PI Contribution | We provide data on our experiments on in vivo activated B cells with genetic manipulation of B cell receptor signalling (IgMg1, IgMDg1, and IgDg1 mice). |
Collaborator Contribution | Gene manipulated mice with B cell specific Cre expression were provided. B cell lines are being developed with similar genetic manipulation of B cell receptor signalling, similar to our GM mouse lines. These will be suitable to test predictions and verify outcomes from our in vivo experiments in vitro. |
Impact | New cell lines and new genetically manipulated mouse lines |
Start Year | 2017 |