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Publications

Open Access
Petersone L, Wang CJ, Edner NM, Fabri A, Nikou SA, Hinze C, Ross EM, Ntavli E, Elfaki Y, Heuts F, Ovcinnikovs V, Rueda Gonzalez A, Houghton LP, Li HM, Zhang Y, Toellner KM, Walker LSK Immunology

Germinal center (GC) dysregulation has been widely reported in the context of autoimmunity. Here, we show that interleukin 21 (IL-21), the archetypal follicular helper T cell (Tfh) cytokine, shapes the scale and polarization of spontaneous chronic autoimmune as well as transient immunization-induced GC. We find that IL-21 receptor deficiency results in smaller GC that are profoundly skewed toward a light zone GC B cell phenotype and that IL-21 plays a key role in selection of light zone GC B cells for entry to the dark zone. Light zone skewing has been previously reported in mice lacking the cell cycle regulator cyclin D3. We demonstrate that IL-21 triggers cyclin D3 upregulation in GC B cells, thereby tuning dark zone inertial cell cycling. Lastly, we identify Foxo1 regulation as a link between IL-21 signaling and GC dark zone formation. These findings reveal new biological roles for IL-21 within GC and have implications for autoimmune settings where IL-21 is overproduced.

+view abstract The Journal of experimental medicine, PMID: 37466652 02 Oct 2023

Open Access
Zhang Y, Garcia-Ibanez L, Ulbricht C, Lok LSC, Pike JA, Mueller-Winkler J, Dennison TW, Ferdinand JR, Burnett CJM, Yam-Puc JC, Zhang L, Alfaro RM, Takahama Y, Ohigashi I, Brown G, Kurosaki T, Tybulewicz VLJ, Rot A, Hauser AE, Clatworthy MR, Toellner KM Immunology

Infection or vaccination leads to the development of germinal centers (GC) where B cells evolve high affinity antigen receptors, eventually producing antibody-forming plasma cells or memory B cells. Here we follow the migratory pathways of B cells emerging from germinal centers (B) and find that many B cells migrate into the lymph node subcapsular sinus (SCS) guided by sphingosine-1-phosphate (S1P). From the SCS, B cells may exit the lymph node to enter distant tissues, while some B cells interact with and take up antigen from SCS macrophages, followed by CCL21-guided return towards the GC. Disruption of local CCL21 gradients inhibits the recycling of B cells and results in less efficient adaption to antigenic variation. Our findings thus suggest that the recycling of antigen variant-specific B cells and transport of antigen back to GC may support affinity maturation to antigenic drift.

+view abstract Nature communications, PMID: 35513371 05 May 2022

Open Access
Yam-Puc JC, Zhang L, Maqueda-Alfaro RA, Garcia-Ibanez L, Zhang Y, Davies J, Senis YA, Snaith M, Toellner KM Immunology

It is still not clear how B cell receptor (BCR) signaling intensity affects plasma cell (PC) and germinal center (GC) B cell differentiation. We generated Cγ1 Ptpn6 mice where SHP-1, a negative regulator of BCR signaling, is deleted rapidly after B cell activation. Although immunization with T-dependent antigens increased BCR signaling, it led to PC reduction and increased apoptosis. Dependent on the antigen, the early GC B cell response was equally reduced and apoptosis increased. At the same time, a higher proportion of GC B cells expressed cMYC, suggesting GC B cell-Tfh cell interactions may be increased. GC B cell numbers returned to normal at later stages, whereas affinity maturation was suppressed in the long term. This confirms that BCR signaling not only directs affinity-dependent B cell selection but also, without adequate further stimulation, can inflict cell death, which may be important for the maintenance of B cell tolerance.

+view abstract iScience, PMID: 33532715 19 Feb 2021

Open Access
Roco JA, Mesin L, Binder SC, Nefzger C, Gonzalez-Figueroa P, Canete PF, Ellyard J, Shen Q, Robert PA, Cappello J, Vohra H, Zhang Y, Nowosad CR, Schiepers A, Corcoran LM, Toellner KM, Polo JM, Meyer-Hermann M, Victora GD, Vinuesa CG Immunology

Class-switch recombination (CSR) is a DNA recombination process that replaces the immunoglobulin (Ig) constant region for the isotype that can best protect against the pathogen. Dysregulation of CSR can cause self-reactive BCRs and B cell lymphomas; understanding the timing and location of CSR is therefore important. Although CSR commences upon T cell priming, it is generally considered a hallmark of germinal centers (GCs). Here, we have used multiple approaches to show that CSR is triggered prior to differentiation into GC B cells or plasmablasts and is greatly diminished in GCs. Despite finding a small percentage of GC B cells expressing germline transcripts, phylogenetic trees of GC BCRs from secondary lymphoid organs revealed that the vast majority of CSR events occurred prior to the onset of somatic hypermutation. As such, we have demonstrated the existence of IgM-dominated GCs, which are unlikely to occur under the assumption of ongoing switching.

+view abstract Immunity, PMID: 31375460 20 Aug 2019

Open Access
Yam-Puc JC, Zhang L, Zhang Y, Toellner KM Immunology

B-cell development is characterized by a number of tightly regulated selection processes. Signals through the B-cell receptor (BCR) guide and are required for B-cell maturation, survival, and fate decision. Here, we review the role of the BCR during B-cell development, leading to the emergence of B1, marginal zone, and peripheral follicular B cells. Furthermore, we discuss BCR-derived signals on activated B cells that lead to germinal center and plasma cell differentiation.

+view abstract F1000Research, PMID: 30090624 2018

Linterman MA, Toellner KM Immunology,

+view abstract Nature immunology, PMID: 29044242 2017

Bénézech C, Luu NT, Walker JA, Kruglov AA, Loo Y, Nakamura K, Zhang Y, Nayar S, Jones LH, Flores-Langarica A, McIntosh A, Marshall J, Barone F, Besra G, Miles K, Allen JE, Gray M, Kollias G, Cunningham AF, Withers DR, Toellner KM, Jones ND, Veldhoen M, Nedospasov SA, McKenzie AN, Caamaño JH Immunology,

Fat-associated lymphoid clusters (FALCs) are a type of lymphoid tissue associated with visceral fat. Here we found that the distribution of FALCs was heterogeneous, with the pericardium containing large numbers of these clusters. FALCs contributed to the retention of B-1 cells in the peritoneal cavity through high expression of the chemokine CXCL13, and they supported B cell proliferation and germinal center differentiation during peritoneal immunological challenges. FALC formation was induced by inflammation, which triggered the recruitment of myeloid cells that expressed tumor-necrosis factor (TNF) necessary for signaling via the TNF receptors in stromal cells. Natural killer T cells (NKT cells) restricted by the antigen-presenting molecule CD1d were likewise required for the inducible formation of FALCs. Thus, FALCs supported and coordinated the activation of innate B cells and T cells during serosal immune responses.

+view abstract Nature immunology, PMID: 26147686 2015

E Vigorito, KL Perks, C Abreu-Goodger, S Bunting, Z Xiang, S Kohlhaas, PP Das, EA Miska, A Rodriguez, A Bradley, KG Smith, C Rada, AJ Enright, KM Toellner, IC Maclennan, M Turner Immunology,

microRNA-155 (miR-155) is expressed by cells of the immune system after activation and has been shown to be required for antibody production after vaccination with attenuated Salmonella. Here we show the intrinsic requirement for miR-155 in B cell responses to thymus-dependent and -independent antigens. B cells lacking miR-155 generated reduced extrafollicular and germinal center responses and failed to produce high-affinity IgG1 antibodies. Gene-expression profiling of activated B cells indicated that miR-155 regulates an array of genes with diverse function, many of which are predicted targets of miR-155. The transcription factor Pu.1 is validated as a direct target of miR155-mediated inhibition. When Pu.1 is overexpressed in wild-type B cells, fewer IgG1 cells are produced, indicating that loss of Pu.1 regulation is a contributing factor to the miR-155-deficient phenotype. Our results implicate post-transcriptional regulation of gene expression for establishing the terminal differentiation program of B cells.

+view abstract Immunity, PMID: 18055230 2007

Gulbranson-Judge A, Tybulewicz VL, Walters AE, Toellner KM, MacLennan IC, Turner M Immunology,

Vav, a guanine nucleotide exchange factor for members of the Rho family of small GTPases, is activated through engagement of B and T lymphocyte antigen receptors. It is important for establishing the signaling threshold of the TCR, as mice lacking Vav display defective thymocyte selection. Here, conventional B cells are shown to develop normally in Vav-deficient mice but these mice have few B-1 B cells. The threshold for inducing B cell proliferation through BCR engagement in vitro is greater in Vav-deficient B cells. Nevertheless, in vivo the mutant mice have normal antibody responses to haptenated Ficoll. In contrast, Vav-/- mice show defective class switching to IgG and germinal center formation when immunized with haptenated protein. Interestingly, this defect is reversed in chimeras where normal T cells are present. Antigen-specific proliferation of T cells in the T zone was found to be similar in wild-type and Vav-/- mice but the induction of IL-4 mRNA and switch transcripts was specifically impaired. These results suggest that defective immunoglobulin class switching in Vav-deficient mice is attributable to compromised T cell help.

+view abstract European journal of immunology, PMID: 10064063 1999