1
|
Carroll SL, Pasare C, Barton GM. Control of adaptive immunity by pattern recognition receptors. Immunity 2024; 57:632-648. [PMID: 38599163 PMCID: PMC11037560 DOI: 10.1016/j.immuni.2024.03.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 04/12/2024]
Abstract
One of the most significant conceptual advances in immunology in recent history is the recognition that signals from the innate immune system are required for induction of adaptive immune responses. Two breakthroughs were critical in establishing this paradigm: the identification of dendritic cells (DCs) as the cellular link between innate and adaptive immunity and the discovery of pattern recognition receptors (PRRs) as a molecular link that controls innate immune activation as well as DC function. Here, we recount the key events leading to these discoveries and discuss our current understanding of how PRRs shape adaptive immune responses, both indirectly through control of DC function and directly through control of lymphocyte function. In this context, we provide a conceptual framework for how variation in the signals generated by PRR activation, in DCs or other cell types, can influence T cell differentiation and shape the ensuing adaptive immune response.
Collapse
Affiliation(s)
- Shaina L Carroll
- Division of Immunology & Molecular Medicine, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA USA
| | - Chandrashekhar Pasare
- Division of Immunobiology and Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, OH USA
| | - Gregory M Barton
- Division of Immunology & Molecular Medicine, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA USA; Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720 USA.
| |
Collapse
|
2
|
Wibrand C, Wittenborn TR, Voss LF, Winther G, Jensen L, Ferapontov A, Fonager SV, Fahlquist-Hagert C, Degn SE. B cell MHC haplotype affects follicular inclusion, germinal center participation and plasma cell differentiation in a mouse model of lupus. Front Immunol 2023; 14:1258046. [PMID: 38090594 PMCID: PMC10715410 DOI: 10.3389/fimmu.2023.1258046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 10/30/2023] [Indexed: 12/18/2023] Open
Abstract
Introduction MHC class II molecules are essential for appropriate immune responses against pathogens but are also implicated in pathological responses in autoimmune diseases and transplant rejection. Previous studies have shed light on the systemic contributions of MHC haplotypes to the development and severity of autoimmune diseases. In this study, we addressed the B cell intrinsic MHC haplotype impact on follicular inclusion, germinal center (GC) participation and plasma cell (PC) differentiation in the context of systemic lupus erythematosus (SLE). Methods We leveraged the 564Igi mouse model which harbors a B cell receptor knock-in from an autoreactive B cell clone recognizing ribonuclear components, including double-stranded DNA (dsDNA). This model recapitulates the central hallmarks of the early stages of SLE. We compared 564Igi heterozygous offspring on either H2b/b, H2b/d, or H2d/d background. Results This revealed significantly higher germinal center (GC) B cell levels in the spleens of H2b/b and H2b/d as compared to H2d/d (p<0.0001) mice. In agreement with this, anti-dsDNA-antibody levels were higher in H2b/b and H2b/d than in H2d/d (p<0.0001), with H2b/b also being higher compared to H2b/d (p<0.01). Specifically, these differences held true both for autoantibodies derived from the knock-in clone and from wild-type (WT) derived clones. In mixed chimeras where 564Igi H2b/b, H2b/d and H2d/d cells competed head-to-head in the same environment, we observed a significantly higher inclusion of H2b/b cells in GC and PC compartments relative to their representation in the B cell repertoire, compared to H2b/d and H2d/d cells. Furthermore, in mixed chimeras in which WT H2b/b and WT H2d/d cells competed for inclusion in GCs associated with an epitope spreading process, H2b/b cells participated to a greater extent and contributed more robustly to the PC compartment. Finally, immature WT H2b/b cells had a higher baseline of BCRs with an autoreactive idiotype and were subject to more stringent negative selection at the transitional stage. Discussion Taken together, our findings demonstrate that B cell intrinsic MHC haplotype governs their capacity for participation in the autoreactive response at multiple levels: follicular inclusion, GC participation, and PC output. These findings pinpoint B cells as central contributors to precipitation of autoimmunity.
Collapse
Affiliation(s)
- Camilla Wibrand
- Laboratory for Lymphocyte Biology, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Thomas R. Wittenborn
- Laboratory for Lymphocyte Biology, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Lasse Frank Voss
- Laboratory for Lymphocyte Biology, Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Gudrun Winther
- Laboratory for Lymphocyte Biology, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Lisbeth Jensen
- Laboratory for Lymphocyte Biology, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Alexey Ferapontov
- Laboratory for Lymphocyte Biology, Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus, Denmark
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
| | - Sofie V. Fonager
- Laboratory for Lymphocyte Biology, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Cecilia Fahlquist-Hagert
- Laboratory for Lymphocyte Biology, Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Søren E. Degn
- Laboratory for Lymphocyte Biology, Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Center for Cellular Signal Patterns (CellPAT), Aarhus University, Aarhus, Denmark
| |
Collapse
|
3
|
Voss LF, Howarth AJ, Wittenborn TR, Hummelgaard S, Juul-Madsen K, Kastberg KS, Pedersen MK, Jensen L, Papanastasiou AD, Vorup-Jensen T, Weyer K, Degn SE. The extrafollicular response is sufficient to drive initiation of autoimmunity and early disease hallmarks of lupus. Front Immunol 2022; 13:1021370. [PMID: 36591222 PMCID: PMC9795406 DOI: 10.3389/fimmu.2022.1021370] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 11/02/2022] [Indexed: 12/15/2022] Open
Abstract
Introduction Many autoimmune diseases are characterized by germinal center (GC)-derived, affinity-matured, class-switched autoantibodies, and strategies to block GC formation and progression are currently being explored clinically. However, extrafollicular responses can also play a role. The aim of this study was to investigate the contribution of the extrafollicular pathway to autoimmune disease development. Methods We blocked the GC pathway by knocking out the transcription factor Bcl-6 in GC B cells, leaving the extrafollicular pathway intact. We tested the impact of this intervention in two murine models of systemic lupus erythematosus (SLE): a pharmacological model based on chronic epicutaneous application of the Toll-like receptor (TLR)-7 agonist Resiquimod (R848), and 564Igi autoreactive B cell receptor knock-in mice. The B cell intrinsic effects were further investigated in vitro and in autoreactive mixed bone marrow chimeras. Results GC block failed to curb autoimmune progression in the R848 model based on anti-dsDNA and plasma cell output, superoligomeric DNA complexes, and immune complex deposition in glomeruli. The 564Igi model confirmed this based on anti-dsDNA and plasma cell output. In vitro, loss of Bcl-6 prevented GC B cell expansion and accelerated plasma cell differentiation. In a competitive scenario in vivo, B cells harboring the genetic GC block contributed disproportionately to the plasma cell output. Discussion We identified the extrafollicular pathway as a key contributor to autoimmune progression. We propose that therapeutic targeting of low quality and poorly controlled extrafollicular responses could be a desirable strategy to curb autoreactivity, as it would leave intact the more stringently controlled and high-quality GC responses providing durable protection against infection.
Collapse
Affiliation(s)
- Lasse F. Voss
- Department of Biomedicine, Aarhus University, Aarhus, Denmark,Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | | | | | | | | | | | - Lisbeth Jensen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | | | - Kathrin Weyer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Søren E. Degn
- Department of Biomedicine, Aarhus University, Aarhus, Denmark,*Correspondence: Søren E. Degn,
| |
Collapse
|