scholarly journals The transcription factor Foxo1 controls germinal center B cell proliferation in response to T cell help

2017 ◽  
Vol 214 (4) ◽  
pp. 1181-1198 ◽  
Author(s):  
Takeshi Inoue ◽  
Ryo Shinnakasu ◽  
Wataru Ise ◽  
Chie Kawai ◽  
Takeshi Egawa ◽  
...  

Germinal center (GC) B cells cycle between two states, the light zone (LZ) and the dark zone (DZ), and in the latter they proliferate and hypermutate their immunoglobulin genes. How this functional transition takes place is still controversial. In this study, we demonstrate that ablation of Foxo1 after GC development led to the loss of the DZ GC B cells and disruption of the GC architecture, which is consistent with recent studies. Mechanistically, even upon provision of adequate T cell help, Foxo1-deficient GC B cells showed less proliferative expansion than controls. Moreover, we found that the transcription factor BATF was transiently induced in LZ GC B cells in a Foxo1-dependent manner and that deletion of BATF similarly led to GC disruption. Thus, our results are consistent with a model where the switch from the LZ to the DZ is triggered after receipt of T cell help, and suggest that Foxo1-mediated BATF up-regulation is at least partly involved in this switch.

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Ting-ting Zhang ◽  
David G Gonzalez ◽  
Christine M Cote ◽  
Steven M Kerfoot ◽  
Shaoli Deng ◽  
...  

To reconcile conflicting reports on the role of CD40 signaling in germinal center (GC) formation, we examined the earliest stages of murine GC B cell differentiation. Peri-follicular GC precursors first expressed intermediate levels of BCL6 while co-expressing the transcription factors RelB and IRF4, the latter known to repress Bcl6 transcription. Transition of GC precursors to the BCL6hi follicular state was associated with cell division, although the number of required cell divisions was immunogen dose dependent. Potentiating T cell help or CD40 signaling in these GC precursors actively repressed GC B cell maturation and diverted their fate towards plasmablast differentiation, whereas depletion of CD4+ T cells promoted this initial transition. Thus while CD40 signaling in B cells is necessary to generate the immediate precursors of GC B cells, transition to the BCL6hi follicular state is promoted by a regional and transient diminution of T cell help.


Immunity ◽  
2019 ◽  
Vol 51 (2) ◽  
pp. 310-323.e7 ◽  
Author(s):  
Michelle A. Mintz ◽  
James H. Felce ◽  
Marissa Y. Chou ◽  
Viveka Mayya ◽  
Ying Xu ◽  
...  

1995 ◽  
Vol 4 (3) ◽  
pp. 189-197 ◽  
Author(s):  
Farida Bouzahzah ◽  
Alain Bosseloir ◽  
Ernst Heinen ◽  
Léon J. Simar

We have isolated two subtypes of helper T cells from human tonsils: CD4+CD57+cells, mostly located in the germinal center (GC), and CD4+CD57-cells, distributed through the interfollicular areas but also present in the GC. In a functional study, we have compared the capacities of these T-cell subtypes to stimulate B cells in cocultures. In order to block T-cell proliferation while maintaining their activation level, we pretreated isolated T cells with mitomycin C prior to culture in the presence of B cells and added polyclonal activators such as PHA and Con A, combined or not with IL-2. Contrary to CD4+CD57-cells, CD4+CD57+cells did not markedly enhance B-cell proliferation. Even when sIgD-B cells typical of germinal center cells were tested, the CD4 CD57 cells had no significant effect. This is in accordance with the location of these cells: They mainly occupy the light zones of the GC where few B cells divide. Even when added to preactivated, actively proliferating cells, CD4+CD57+cells failed to modulate B-cell multiplication. On the supernatants of B-cell-T-cell cocultures, we examined by the ELISA technique the effect of T cells on Ig synthesis. Contrary to CD57-T cells, whose effect was strong, CD57+T cells weakly stimulated Ig synthesis. More IgM than IgG was generally found. Because CD57 antigen is a typical marker of natural killer cells, we tested the cytolytic activity of tonsillar CD4+CD57+cells on K562 target cells. Unlike NK cells, neither CD4+CD57+nor CD4+CD57-cells exhibit any cytotoxicity. Thus, germinal center CD4+CD57+cells are not cytolytic and do not strongly stimulate either B-cell proliferation or Ig secretion. CD4+CD57-cells, however, enhance B-cell proliferation and differentiation, thus acting like the classical helper cells of the T-dependent areas.


Science ◽  
2015 ◽  
Vol 349 (6248) ◽  
pp. 643-646 ◽  
Author(s):  
A. D. Gitlin ◽  
C. T. Mayer ◽  
T. Y. Oliveira ◽  
Z. Shulman ◽  
M. J. K. Jones ◽  
...  

Cell Reports ◽  
2018 ◽  
Vol 25 (6) ◽  
pp. 1395-1403.e4 ◽  
Author(s):  
Jackson Steed Turner ◽  
Fang Ke ◽  
Irina Leonidovna Grigorova

2011 ◽  
Vol 208 (6) ◽  
pp. 1243-1252 ◽  
Author(s):  
Tanja A. Schwickert ◽  
Gabriel D. Victora ◽  
David R. Fooksman ◽  
Alice O. Kamphorst ◽  
Monica R. Mugnier ◽  
...  

The germinal center (GC) reaction is essential for the generation of the somatically hypermutated, high-affinity antibodies that mediate adaptive immunity. Entry into the GC is limited to a small number of B cell clones; however, the process by which this limited number of clones is selected is unclear. In this study, we demonstrate that low-affinity B cells intrinsically capable of seeding a GC reaction fail to expand and become activated in the presence of higher-affinity B cells even before GC coalescence. Live multiphoton imaging shows that selection is based on the amount of peptide–major histocompatibility complex (pMHC) presented to cognate T cells within clusters of responding B and T cells at the T–B border. We propose a model in which T cell help is restricted to the B cells with the highest amounts of pMHC, thus allowing for a dynamic affinity threshold to be imposed on antigen-binding B cells.


2016 ◽  
Author(s):  
Vinod Krishna ◽  
Kurtis E. Bachman

A model of B cell affinity selection is proposed, and an explanation of peripheral tolerance mechanisms through antibody repertoire editing is presented. We show that affinity discrimination between B cells is driven by a competition between obtaining T cell help and removal of B cells from the light zone, either through apoptosis or by a return to the dark zone of germinal centers. We demonstrate that this mechanism also allows for the negative selection of self reactive B cells and maintenance of B cell tolerance during the germinal center reaction. Finally, we demonstrate that clonal expansion upon return to the germinal center dark zone amplifies differences in the antigen affinity of B cells that survive the light zone.


2018 ◽  
Vol 215 (5) ◽  
pp. 1437-1448 ◽  
Author(s):  
Chao Chen ◽  
Sulan Zhai ◽  
Le Zhang ◽  
Jingjing Chen ◽  
Xuehui Long ◽  
...  

The production of high-affinity antibody is essential for pathogen clearance. Antibody affinity is increased through germinal center (GC) affinity maturation, which relies on BCR somatic hypermutation (SHM) followed by antigen-based selection. GC B cell proliferation is essentially involved in these processes; it provides enough templates for SHM and also serves as a critical mechanism of positive selection. In this study, we show that expression of epigenetic regulator ubiquitin-like with PHD and RING finger domains 1 (Uhrf1) was markedly up-regulated by c-Myc–AP4 in GC B cells, and it was required for GC response. Uhrf1 regulates cell proliferation–associated genes including cdkn1a, slfn1, and slfn2 by DNA methylation, and its deficiency inhibited the GC B cell cycle at G1-S phase. Subsequently, GC B cell SHM and affinity maturation were impaired, and Uhrf1 GC B knockout mice were unable to control chronic virus infection. Collectively, our data suggest that Uhrf1 regulates GC B cell proliferation and affinity maturation, and its expression in GC B cells is required for virus clearance.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3905-3905
Author(s):  
Bernd Jahrsdoerfer ◽  
Karen Dahlke ◽  
Magdalena Hagn ◽  
Kai Sontheimer ◽  
Thamara Beyer ◽  
...  

Abstract Abstract 3905 Immune regulation is central for the development of an efficient cellular immune response. Both Treg cells and plasmacytoid DC can suppress T cell proliferation in a granzyme B (GzmB)-dependent and perforin-independent manner. In the present study we found that, depending on stimulation with interleukin (IL-) 21, B cells (BC) can also express GzmB and effectively suppress T cell proliferation. GzmB expression in BC is enhanced by BC receptor engagement, and is suppressed by CD40 ligation. Since CD4+ T cells are a main source of IL-21, we tested whether they can induce GzmB in BC. We found that incompletely activated CD4+ T cells, but not fully activated T cells induce GzmB in co-cultured BC. Using confocal microscopy, we showed that BC-derived GzmB is enzymatically active and that GzmB+ BC transfer GzmB to CD4+ T cells. Furthermore, GzmB+ BC decreased CD4+ T cell expression of the TCR-zeta chain, a GzmB target, which is required for T cell proliferation. Our results suggest BC may regulate cellular adaptive immune responses by Treg cell-like mechanisms. Inhibition of BC-derived GzmB may represent a novel strategy to induce more effective and comprehensive cellular immune responses. Disclosures: No relevant conflicts of interest to declare.


Sign in / Sign up

Export Citation Format

Share Document