scholarly journals ICOS expression is required for maintenance but not the formation of germinal centers in the spleen in response to P. yoelii infection.

2022 ◽  
Author(s):  
Kara A. O’Neal ◽  
Leah E. Latham ◽  
Enatha Ntirandekura ◽  
Camille L. Foscue ◽  
Jason S. Stumhofer
Keyword(s):  
Germinal Center ◽  
Primary Infection ◽  
Germinal Centers ◽  
Affinity Maturation ◽  
Infection Model ◽  
Wild Type ◽  
Plasmodium Chabaudi ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Functional Defects

Inducible T cell co-stimulator (ICOS) plays a key role in the differentiation and maintenance of follicular helper T (Tfh) cells and thus germinal center (GC) formation. Previously, our lab showed in a Plasmodium chabaudi infection model that Icos -/- mice were significantly impaired in their ability to form GCs despite a persistent infection and thus a continued antigen (Ag) load. Here, we show that resolution of a primary infection with P. yoelii , was delayed in Icos -/- mice. This phenotype was associated with a reduction in the accumulation of Tfh-like and GC Tfh cells and an early deficiency in Ag-specific antibody (Ab) production. However, Icos -/- mice could form GCs, though they were less frequent in number than in wild-type (WT) mice. Nonetheless, the Ag-specific Abs from Icos -/- mice lacked signs of affinity maturation, suggesting functional defects associated with these GCs. Eventually, these GC structures dissipated more rapidly in Icos -/- mice than in WT mice. Moreover, the ability of Icos -/- mice to form these GC structures is not reliant on the high Ag load associated with P. yoelii infections, as GC formation was preserved in Icos -/- mice treated with atovaquone. Finally, mice were unable to form secondary GCs in the absence of ICOS after re-challenge. Overall, these data demonstrate the necessity of ICOS in the maintenance of Tfh cells, the formation and maintenance of sufficient numbers of functioning GCs, and the ability to generate new GC structures after re-infection with P. yoelii .

scholarly journals ICOS expression is required for maintenance but not the formation of germinal centers in the spleen in response to P. yoelii infection.

2021 ◽  
Author(s):  
Jason Stumhofer ◽  
Kara A O'Neal ◽  
Leah E Latham ◽  
Enatha Ntirandekura ◽  
Camille L Foscue
Keyword(s):  
Germinal Center ◽  
Primary Infection ◽  
Germinal Centers ◽  
Affinity Maturation ◽  
Infection Model ◽  
Wild Type ◽  
Plasmodium Chabaudi ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Functional Defects

Inducible T cell co-stimulator (ICOS) plays a key role in the differentiation and maintenance of follicular helper T (Tfh) cells and thus germinal center (GC) formation. Previously, our lab showed in a Plasmodium chabaudi infection model that Icos-/- mice did not form GCs despite a persistent infection and thus a continued antigen (Ag) load. Here, we show that resolution of a primary infection with P. yoelii, was delayed in Icos-/- mice. This phenotype was associated with a reduction in the accumulation of Tfh-like and GC Tfh cells and an early deficiency in Ag-specific antibody (Ab) production. However, Icos-/- mice maintained their ability to form GCs, though they were less frequent in number than in wild-type (WT) mice. Furthermore, while Ab production in Icos-/- mice matched that of WT mice after the infection cleared, the Abs lacked signs of affinity maturation, suggesting functional defects associated with these GCs. Eventually, these GC structures dissipated more rapidly in Icos-/-mice than in WT mice. Moreover, the ability of Icos-/- mice to form these GC structures is not reliant on the high Ag load associated with P. yoelii infections, as GC formation was preserved in Icos-/- mice treated with early with atovaquone. Finally, mice were unable to form secondary GCs in the absence of ICOS after re-challenge. Overall, these data demonstrate the necessity of ICOS in the maintenance of Tfh cells, the formation and maintenance of sufficient numbers of functioning GCs, and the ability to generate new GC structures after re-infection with P. yoelii.

scholarly journals A distinct subpopulation of CD25− T-follicular regulatory cells localizes in the germinal centers

2017 ◽  
Vol 114 (31) ◽  
pp. E6400-E6409 ◽  
Author(s):  
James Badger Wing ◽  
Yohko Kitagawa ◽  
Michela Locci ◽  
Hannah Hume ◽  
Christopher Tay ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
Germinal Center ◽  
Germinal Centers ◽  
Regulatory Cells ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Distinct Subpopulation ◽  
Wide Range ◽  
Multistep Process

T-follicular helper (Tfh) cells differentiate through a multistep process, culminating in germinal center (GC) localized GC-Tfh cells that provide support to GC-B cells. T-follicular regulatory (Tfr) cells have critical roles in the control of Tfh cells and GC formation. Although Tfh-cell differentiation is inhibited by IL-2, regulatory T (Treg) cell differentiation and survival depend on it. Here, we describe a CD25− subpopulation within both murine and human PD1+CXCR5+Foxp3+ Tfr cells. It is preferentially located in the GC and can be clearly differentiated from CD25+ non–GC-Tfr, Tfh, and effector Treg (eTreg) cells by the expression of a wide range of molecules. In comparison to CD25+ Tfr and eTreg cells, CD25− Tfr cells partially down-regulate IL-2–dependent canonical Treg features, but retain suppressive function, while simultaneously up-regulating genes associated with Tfh and GC-Tfh cells. We suggest that, similar to Tfh cells, Tfr cells follow a differentiation pathway generating a mature GC-localized subpopulation, CD25− Tfr cells.

scholarly journals Sphingosine-1-phosphate receptor 2 is critical for follicular helper T cell retention in germinal centers

2014 ◽  
Vol 211 (7) ◽  
pp. 1297-1305 ◽  
Author(s):  
Saya Moriyama ◽  
Noriko Takahashi ◽  
Jesse A. Green ◽  
Shohei Hori ◽  
Masato Kubo ◽  
...  
Keyword(s):  
T Cells ◽  
Germinal Center ◽  
Molecular Mechanisms ◽  
Germinal Centers ◽  
Antibody Responses ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Sphingosine 1 Phosphate ◽  
Follicular Helper T Cell ◽  
Cell Follicle

Follicular helper T (Tfh) cells access the B cell follicle to promote antibody responses and are particularly important for germinal center (GC) reactions. However, the molecular mechanisms of how Tfh cells are physically associated with GCs are incompletely understood. We report that the sphingosine-1-phosphate receptor 2 (S1PR2) gene is highly expressed in a subpopulation of Tfh cells that localizes in GCs. S1PR2-deficient Tfh cells exhibited reduced accumulation in GCs due to their impaired retention. T cells deficient in both S1PR2 and CXCR5 were ineffective in supporting GC responses compared with T cells deficient only in CXCR5. These results suggest that S1PR2 and CXCR5 cooperatively regulate localization of Tfh cells in GCs to support GC responses.

scholarly journals The Development of Optimally Responsive Plasmodium-specific CD73+CD80+ IgM+ Memory B cells Requires Intrinsic BCL6 expression but not CD4+ Tfh cells

2019 ◽  
Author(s):  
Gretchen Harms Pritchard ◽  
Akshay T. Krishnamurty ◽  
Jason Netland ◽  
E. Nicole Arroyo ◽  
Kennidy K. Takehara ◽  
...  
Keyword(s):  
B Cells ◽  
Germinal Center ◽  
Plasma Cells ◽  
Germinal Centers ◽  
Memory B Cells ◽  
Effector Cells ◽  
High Affinity ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Bcl6 Expression

SummaryHumoral immunity depends upon the development of long-lived, antibody-secreting plasma cells and rapidly responsive memory B cells (MBCs). The differentiation of high affinity, class-switched MBCs after immunization is critically dependent upon BCL6 expression in germinal center (GC) B cells and CD4+ T follicular helper (Tfh) cells. It is less well understood how more recently described MBC subsets are generated, including the CD73+CD80+ IgM+ MBCs that initially form antibody-secreting effector cells in response to a secondary Plasmodium infection. Herein, we interrogated how BCL6 expression in both B and CD4+ T cells influenced the formation of heterogeneous Plasmodium-specific MBC populations. All Plasmodium-specific CD73+CD80+ MBCs required BCL6 expression for their formation, suggesting germinal center dependence. Further dissection of the CD4+ T and B cell interactions however revealed that somatically hypermutated CD73+CD80+ IgM+ MBCs can form not only in the absence of germinal centers, but also in the absence of CXCR5+ CD4+ Tfh cells.

scholarly journals Cbl and Cbl-b control the germinal center reaction by facilitating naive B cell antigen processing

2020 ◽  
Vol 217 (9) ◽  
Author(s):  
Xin Li ◽  
Liying Gong ◽  
Alexandre P. Meli ◽  
Danielle Karo-Atar ◽  
Weili Sun ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Antigen Processing ◽  
Cell Interaction ◽  
Affinity Maturation ◽  
Antigen Uptake ◽  
Cell Antigen ◽  
Germinal Center Reaction ◽  
Follicular Helper

Antigen uptake and presentation by naive and germinal center (GC) B cells are different, with the former expressing even low-affinity BCRs efficiently capture and present sufficient antigen to T cells, whereas the latter do so more efficiently after acquiring high-affinity BCRs. We show here that antigen uptake and processing by naive but not GC B cells depend on Cbl and Cbl-b (Cbls), which consequently control naive B and cognate T follicular helper (Tfh) cell interaction and initiation of the GC reaction. Cbls mediate CD79A and CD79B ubiquitination, which is required for BCR-mediated antigen endocytosis and postendocytic sorting to lysosomes, respectively. Blockade of CD79A or CD79B ubiquitination or Cbls ligase activity is sufficient to impede BCR-mediated antigen processing and GC development. Thus, Cbls act at the entry checkpoint of the GC reaction by promoting naive B cell antigen presentation. This regulation may facilitate recruitment of naive B cells with a low-affinity BCR into GCs to initiate the process of affinity maturation.

scholarly journals IL-21 acts directly on B cells to regulate Bcl-6 expression and germinal center responses

2010 ◽  
Vol 207 (2) ◽  
pp. 353-363 ◽  
Author(s):  
Michelle A. Linterman ◽  
Laura Beaton ◽  
Di Yu ◽  
Roybel R. Ramiscal ◽  
Monika Srivastava ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Plasma Cells ◽  
Cell Formation ◽  
Affinity Maturation ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Early Memory ◽  
Bone Marrow Chimeras ◽  
Follicular Response

During T cell–dependent responses, B cells can either differentiate extrafollicularly into short-lived plasma cells or enter follicles to form germinal centers (GCs). Interactions with T follicular helper (Tfh) cells are required for GC formation and for selection of somatically mutated GC B cells. Interleukin (IL)-21 has been reported to play a role in Tfh cell formation and in B cell growth, survival, and isotype switching. To date, it is unclear whether the effect of IL-21 on GC formation is predominantly a consequence of this cytokine acting directly on the Tfh cells or if IL-21 directly influences GC B cells. We show that IL-21 acts in a B cell–intrinsic fashion to control GC B cell formation. Mixed bone marrow chimeras identified a significant B cell–autonomous effect of IL-21 receptor (R) signaling throughout all stages of the GC response. IL-21 deficiency profoundly impaired affinity maturation and reduced the proportion of IgG1+ GC B cells but did not affect formation of early memory B cells. IL-21R was required on GC B cells for maximal expression of Bcl-6. In contrast to the requirement for IL-21 in the follicular response to sheep red blood cells, a purely extrafollicular antibody response to Salmonella dominated by IgG2a was intact in the absence of IL-21.

Th17 Cells and Associated Cytokines in Inflammation and Cancer

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. SCI-5-SCI-5
Author(s):  
Chen Dong
Keyword(s):  
T Cells ◽  
Germinal Center ◽  
Th17 Cells ◽  
The Other ◽  
Th Cells ◽  
Tissue Inflammation ◽  
Tfh Cells ◽  
Follicular Helper ◽  
And Function ◽  
Th1 And Th2

Abstract Abstract SCI-5 CD4+ T cells, upon activation, differentiate into cytokine-producing effector helper T (TH) cells. In addition to TH1 and TH2 lineage cells, additional TH subsets, including TH17 and T follicular helper (Tfh) cells have been identified. TH17 cells produce IL-17, IL-17F, IL-21, and IL-22 and mediate tissue inflammation. TH17 cells play protective or pathogenic roles in cancer, depending on the context. On the other hand, Tfh cells produce IL-21 and regulate germinal center reactions. Tfh cells may play a role in some forms of lymphoma. I will discuss on the regulation and function of these two subsets of T cells in the context of cancer. Disclosures: Dong: Ono: Consultancy; Tempero: Consultancy; Genentech: Honoraria; GSK: Consultancy; AnaptysBio: Consultancy.

scholarly journals Regulation of Intrinsic and Bystander T Follicular Helper Cell Differentiation and Autoimmunity by Tsc1

2021 ◽  
Vol 12 ◽  
Author(s):  
Shimeng Zhang ◽  
Lei Li ◽  
Danli Xie ◽  
Srija Reddy ◽  
John W. Sleasman ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
Immune Responses ◽  
B Cell ◽  
Regulatory Cells ◽  
Wild Type ◽  
Autoantibody Production ◽  
Cell Responses ◽  
Tfh Cells ◽  
Follicular Helper

T Follicular helper (Tfh) cells promote germinal center (GC) B cell responses to develop effective humoral immunity against pathogens. However, dysregulated Tfh cells can also trigger autoantibody production and the development of autoimmune diseases. We report here that Tsc1, a regulator for mTOR signaling, plays differential roles in Tfh cell/GC B cell responses in the steady state and in immune responses to antigen immunization. In the steady state, Tsc1 in T cells intrinsically suppresses spontaneous GC-Tfh cell differentiation and subsequent GC-B cell formation and autoantibody production. In immune responses to antigen immunization, Tsc1 in T cells is required for efficient GC-Tfh cell expansion, GC-B cell induction, and antigen-specific antibody responses, at least in part via promoting GC-Tfh cell mitochondrial integrity and survival. Interestingly, in mixed bone marrow chimeric mice reconstituted with both wild-type and T cell-specific Tsc1-deficient bone marrow cells, Tsc1 deficiency leads to enhanced GC-Tfh cell differentiation of wild-type CD4 T cells and increased accumulation of wild-type T regulatory cells and T follicular regulatory cells. Such bystander GC-Tfh cell differentiation suggests a potential mechanism that could trigger self-reactive GC-Tfh cell/GC responses and autoimmunity via neighboring GC-Tfh cells.

scholarly journals Cyclin D3 drives inertial cell cycling in dark zone germinal center B cells

2020 ◽  
Author(s):  
Juhee Pae ◽  
Jonatan Ersching ◽  
Tiago B. R. Castro ◽  
Marta Schips ◽  
Luka Mesin ◽  
...  
Keyword(s):  
Cell Cycle ◽  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Clonal Expansion ◽  
Affinity Maturation ◽  
Cyclin D3 ◽  
Dark Zone ◽  
Follicular Helper ◽  
Cell Cycle Regulator Cyclin

AbstractDuring affinity maturation, germinal center (GC) B cells alternate between proliferation and so-matic hypermutation in the dark zone (DZ) and affinity-dependent selection in the light zone (LZ). This anatomical segregation imposes that the vigorous proliferation that allows clonal expansion of positively-selected GC B cells takes place ostensibly in the absence of the signals that triggered selection in the LZ, as if by “inertia.” We find that such inertial cycles specifically require the cell cycle regulator cyclin D3. Cyclin D3 dose-dependently controls the extent to which B cells proliferate in the DZ and is essential for effective clonal expansion of GC B cells in response to strong T follicular helper (Tfh) cell help. Introduction into the Ccnd3 gene of a Burkitt lymphoma-associated gain-of-function mutation (T283A) leads to larger GCs with increased DZ proliferation and, in older mice, to clonal B cell lymphoproliferation, suggesting that the DZ inertial cell cycle program can be coopted by B cells undergoing malignant transformation.

scholarly journals Nucleoside-modified mRNA vaccines induce potent T follicular helper and germinal center B cell responses

2018 ◽  
Vol 215 (6) ◽  
pp. 1571-1588 ◽  
Author(s):  
Norbert Pardi ◽  
Michael J. Hogan ◽  
Martin S. Naradikian ◽  
Kaela Parkhouse ◽  
Derek W. Cain ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Neutralizing Antibodies ◽  
Affinity Maturation ◽  
Modified Nucleosides ◽  
Vaccine Platform ◽  
Intradermal Vaccination ◽  
Cell Responses ◽  
Follicular Helper

T follicular helper (Tfh) cells are required to develop germinal center (GC) responses and drive immunoglobulin class switch, affinity maturation, and long-term B cell memory. In this study, we characterize a recently developed vaccine platform, nucleoside-modified, purified mRNA encapsulated in lipid nanoparticles (mRNA-LNPs), that induces high levels of Tfh and GC B cells. Intradermal vaccination with nucleoside-modified mRNA-LNPs encoding various viral surface antigens elicited polyfunctional, antigen-specific, CD4+ T cell responses and potent neutralizing antibody responses in mice and nonhuman primates. Importantly, the strong antigen-specific Tfh cell response and high numbers of GC B cells and plasma cells were associated with long-lived and high-affinity neutralizing antibodies and durable protection. Comparative studies demonstrated that nucleoside-modified mRNA-LNP vaccines outperformed adjuvanted protein and inactivated virus vaccines and pathogen infection. The incorporation of noninflammatory, modified nucleosides in the mRNA is required for the production of large amounts of antigen and for robust immune responses.

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