scholarly journals Proliferative and differentiative responses of B cells from human marrow graft recipients to T cell-derived factors

Blood ◽  
1987 ◽  
Vol 69 (1) ◽  
pp. 308-315 ◽  
Author(s):  
K Matsue ◽  
LG Lum ◽  
RP Witherspoon ◽  
R Storb
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Chronic Gvhd ◽  
B Cell Activation ◽  
Short Term ◽  
Marrow Graft ◽  
One Year

Abstract Upon activation, B cells express growth and differentiation receptors that permit them to proliferate and differentiate. The aim of this study is to define the nature of the intrinsic B cell defects found in marrow recipients using assays for B cell activation, proliferation, and differentiation. B cells from five short-term (less than three months postgrafting) and 15 long-term (greater than one year postgrafting) marrow recipients (ten with and five without chronic graft-v -host disease [GVHD]) were studied. T cell supernatants (T-sup) were prepared by stimulating normal T cells with 12–0-tetradecanoyl- phorbol-13-acetate (TPA) and phytohemagglutinin. Highly purified B cells were used to assess B cell proliferation responses to T-sup after Staphylococcus aureus Cowan I (SAC) activation and for B cell immunoglobulin production responses to T-sup stimulation after SAC activation. B cells from all five short-term patients and one long-term patient with chronic GVHD did not respond to any stimulation. B cells from two patients with chronic GVHD responded to SAC but had decreased proliferative and differentiative responses to T-sup. B cells from three of seven patients with chronic GVHD and two of five long-term healthy patients could proliferate but could not secrete immunoglobulin in response to SAC plus T-sup stimulation. Furthermore, there was a significant correlation between serum IgG and/or IgM in marrow recipients and the differentiative responses of their B cells to T-sup (P = 0.0075, Fisher's Exact). B cell defects occur at various stages of maturation postgrafting. These defects include the failure to respond to the SAC activation signal, the failure to proliferate in response to T-sup, and the failure to differentiate in response to T-sup. These findings are probably due to the inability of B cells from certain marrow recipients to undergo a second round of ontogeny.

scholarly journals Proliferative and differentiative responses of B cells from human marrow graft recipients to T cell-derived factors

Blood ◽  
1987 ◽  
Vol 69 (1) ◽  
pp. 308-315 ◽  
Author(s):  
K Matsue ◽  
LG Lum ◽  
RP Witherspoon ◽  
R Storb
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Chronic Gvhd ◽  
B Cell Activation ◽  
Short Term ◽  
Marrow Graft ◽  
One Year

Upon activation, B cells express growth and differentiation receptors that permit them to proliferate and differentiate. The aim of this study is to define the nature of the intrinsic B cell defects found in marrow recipients using assays for B cell activation, proliferation, and differentiation. B cells from five short-term (less than three months postgrafting) and 15 long-term (greater than one year postgrafting) marrow recipients (ten with and five without chronic graft-v -host disease [GVHD]) were studied. T cell supernatants (T-sup) were prepared by stimulating normal T cells with 12–0-tetradecanoyl- phorbol-13-acetate (TPA) and phytohemagglutinin. Highly purified B cells were used to assess B cell proliferation responses to T-sup after Staphylococcus aureus Cowan I (SAC) activation and for B cell immunoglobulin production responses to T-sup stimulation after SAC activation. B cells from all five short-term patients and one long-term patient with chronic GVHD did not respond to any stimulation. B cells from two patients with chronic GVHD responded to SAC but had decreased proliferative and differentiative responses to T-sup. B cells from three of seven patients with chronic GVHD and two of five long-term healthy patients could proliferate but could not secrete immunoglobulin in response to SAC plus T-sup stimulation. Furthermore, there was a significant correlation between serum IgG and/or IgM in marrow recipients and the differentiative responses of their B cells to T-sup (P = 0.0075, Fisher's Exact). B cell defects occur at various stages of maturation postgrafting. These defects include the failure to respond to the SAC activation signal, the failure to proliferate in response to T-sup, and the failure to differentiate in response to T-sup. These findings are probably due to the inability of B cells from certain marrow recipients to undergo a second round of ontogeny.

scholarly journals 702 Dual blockade of the PD-1 checkpoint pathway and the adenosinergic negative feedback signaling pathway with a PD-1/CD73 bispecific antibody for cancer immune therapy

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A744-A744
Author(s):  
Tingting Zhong ◽  
Zhaoliang Huang ◽  
Xinghua Pang ◽  
Na Chen ◽  
Xiaoping Jin ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
T Cell Activation ◽  
Negative Feedback ◽  
Immune Suppression ◽  
Specific Antibody ◽  
Cell Activation ◽  
Immune Therapy ◽  
B Cell Activation

BackgroundCD73 (ecto-5’-nucleotidase) is an ecto-nucleotidase that dephosphorylate AMP to form adenosine. Activation of adenosine signaling pathway in immune cells leads to the suppression of effector functions, down-regulate macrophage phagocytosis, inhibit pro-inflammatory cytokine release, as well as yield aberrantly differentiated dendritic cells producing pro-tumorigenic molecules.1 In the tumor microenvironment, adenosinergic negative feedback signaling facilitated immune suppression is considered an important mechanism for immune evasion of cancer cells.2 3 Combination of CD73 and anti-PD-1 antibody has shown promising activity in suppressing tumor growth. Hence, we developed AK119, an anti- human CD73 monoclonal antibody, and AK123,a bi-specific antibody targeting both PD-1 and CD73 for immune therapy of cancer.MethodsAK119 is a humanized antibody against CD73 and AK123 is a tetrameric bi-specific antibody targeting PD-1 and CD73. Binding assays of AK119 and AK123 to antigens, and antigen expressing cells were performed by using ELISA, Fortebio, and FACS assays. In-vitro assays to investigate the activity of AK119 and AK123 to inhibit CD73 enzymatic activity in modified CellTiter-Glo assay, to induce endocytosis of CD73, and to activate B cells were performed. Assay to evaluate AK123 activity on T cell activation were additionally performed. Moreover, the activities of AK119 and AK123 to mediate ADCC, CDC in CD73 expressing cells were also evaluated.ResultsAK119 and AK123 could bind to its respective soluble or membrane antigens expressing on PBMCs, MDA-MB-231, and U87-MG cells with high affinity. Results from cell-based assays indicated that AK119 and AK123 effectively inhibited nucleotidase enzyme activity of CD73, mediated endocytosis of CD73, and induced B cell activation by upregulating CD69 and CD83 expression on B cells, and showed more robust CD73 blocking and B cell activation activities compared to leading clinical candidate targeting CD73. AK123 could also block PD-1/PD-L1 interaction and enhance T cell activation.ConclusionsIn summary, AK119 and AK123 represent good preclinical biological properties, which support its further development as an anti-cancer immunotherapy or treating other diseases.ReferencesDeaglio S, Dwyer KM, Gao W, Friedman D, Usheva A, Erat A, Chen JF, Enjyoji K, Linden J, Oukka M, et al. Adenosine generation catalyzed by CD39 and CD73 expressed on regulatory T cells mediates immune suppression. J Exp Med 2007; 204:1257–65.Huang S, Apasov S, Koshiba M, Sitkovsky M. Role of A2a extracellular adenosine receptor-mediated signaling in adenosine-mediated inhibition of T-cell activation and expansion. Blood. 1997; 90:1600–10.Novitskiy SV, Ryzhov S, Zaynagetdinov R, Goldstein AE, Huang Y, Tikhomirov OY, Blackburn MR, Biaggioni I,Carbone DP, Feoktistov I, et al. Adenosine receptors in regulation of dendritic cell differentiation and function. Blood 2008; 112:1822–31.

scholarly journals Antiviral Protection and Germinal Center Formation, But Impaired B Cell Memory in the Absence of CD19

1998 ◽  
Vol 188 (1) ◽  
pp. 145-155 ◽  
Author(s):  
Thomas Fehr ◽  
Robert C. Rickert ◽  
Bernhard Odermatt ◽  
Jürgen Roes ◽  
Klaus Rajewsky ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Antibody Responses ◽  
B Cell Activation ◽  
Protein Antigens ◽  
Cell Memory ◽  
B Cell Memory

Coligation of CD19, a molecule expressed during all stages of B cell development except plasmacytes, lowers the threshold for B cell activation with anti-IgM by a factor of 100. The cytoplasmic tail of CD19 contains nine tyrosine residues as possible phosphorylation sites and is postulated to function as the signal transducing element for complement receptor (CR)2. Generation and analysis of CD19 gene–targeted mice revealed that T cell–dependent (TD) antibody responses to proteinaceous antigens were impaired, whereas those to T cell–independent (TI) type 2 antigens were normal or even augmented. These results are compatible with earlier complement depletion studies and the postulated function of CD19. To analyze the role of CD19 in antiviral antibody responses, we immunized CD19−/− mice with viral antigens of TI-1, TI-2, and TD type. The effect of CD19 on TI responses was more dependent on antigen dose and replicative capacity than on antigen type. CR blocking experiments confirmed the role of CD19 as B cell signal transducer for complement. In contrast to immunization with protein antigens, infection of CD19−/− mice with replicating virus led to generation of specific germinal centers, which persisted for >100 d, whereas maintenance of memory antibody titers as well as circulating memory B cells was fully dependent on CD19. Thus, our study confirms a costimulatory role of CD19 on B cells under limiting antigen conditions and indicates an important role for B cell memory.

scholarly journals T Cell Accumulation in B Cell Follicles Is Regulated by Dendritic Cells and Is Independent of B Cell Activation

2003 ◽  
Vol 197 (2) ◽  
pp. 195-206 ◽  
Author(s):  
Simon Fillatreau ◽  
David Gray
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
B Cell Activation ◽  
Cell Accumulation ◽  
Antigen Presenting ◽  
Deficient Mice

We investigated the mechanism of CD4 T cell accumulation in B cell follicles after immunization. Follicular T cell numbers were correlated with the number of B cells, indicating B cell control of the niche that T cells occupy. Despite this, we found no role for B cells in the follicular migration of T cells. Instead, T cells are induced to migrate into B cell follicles entirely as a result of interaction with dendritic cells (DCs). Migration relies on CD40-dependent maturation of DCs, as it did not occur in CD40-deficient mice but was reconstituted with CD40+ DCs. Restoration was not achieved by the activation of DCs with bacterial activators (e.g., lipopolysaccharide, CpG), but was by the injection of OX40L–huIgG1 fusion protein. Crucially, the up-regulation of OX40L (on antigen-presenting cells) and CXCR-5 (on T cells) are CD40-dependent events and we show that T cells do not migrate to follicles in immunized OX40-deficient mice.

scholarly journals Extrafollicular B cell activation by marginal zone dendritic cells drives T cell–dependent antibody responses

2012 ◽  
Vol 209 (10) ◽  
pp. 1825-1840 ◽  
Author(s):  
Craig P. Chappell ◽  
Kevin E. Draves ◽  
Natalia V. Giltiay ◽  
Edward A. Clark
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Marginal Zone ◽  
Receptor Expression ◽  
B Cell Activation ◽  
Cell Responses ◽  
B Cell Responses

Dendritic cells (DCs) are best known for their ability to activate naive T cells, and emerging evidence suggests that distinct DC subsets induce specialized T cell responses. However, little is known concerning the role of DC subsets in the initiation of B cell responses. We report that antigen (Ag) delivery to DC-inhibitory receptor 2 (DCIR2) found on marginal zone (MZ)–associated CD8α− DCs in mice leads to robust class-switched antibody (Ab) responses to a T cell–dependent (TD) Ag. DCIR2+ DCs induced rapid up-regulation of multiple B cell activation markers and changes in chemokine receptor expression, resulting in accumulation of Ag-specific B cells within extrafollicular splenic bridging channels as early as 24 h after immunization. Ag-specific B cells primed by DCIR2+ DCs were remarkably efficient at driving naive CD4 T cell proliferation, yet DCIR2-induced responses failed to form germinal centers or undergo affinity maturation of serum Ab unless toll-like receptor (TLR) 7 or TLR9 agonists were included at the time of immunization. These results demonstrate DCIR2+ DCs have a unique capacity to initiate extrafollicular B cell responses to TD Ag, and thus define a novel division of labor among splenic DC subsets for B cell activation during humoral immune responses.

scholarly journals Antigen presentation by resting B cells. Radiosensitivity of the antigen-presentation function and two distinct pathways of T cell activation.

1984 ◽  
Vol 159 (3) ◽  
pp. 881-905 ◽  
Author(s):  
J D Ashwell ◽  
A L DeFranco ◽  
W E Paul ◽  
R H Schwartz
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Antigen Presentation ◽  
Cell Activation ◽  
T Cell Proliferation ◽  
B Cell Activation ◽  
Antigen Presenting

In this report we have examined the ability of small resting B cells to act as antigen-presenting cells (APC) to antigen-specific MHC-restricted T cells as assessed by either T cell proliferation or T cell-dependent B cell stimulation. We found that 10 of 14 in vitro antigen-specific MHC-restricted T cell clones and lines and three of four T cell hybridomas could be induced to either proliferate or secrete IL-2 in the presence of lightly irradiated (1,000 rads) purified B cells and the appropriate foreign antigen. All T cell lines and hybridomas were stimulated to proliferate or make IL-2 by macrophage- and dendritic cell-enriched populations and all T cells tested except one hybridoma caused B cell activation when stimulated with B cells as APC. Furthermore, lightly irradiated, highly purified syngeneic B cells were as potent a source of APC for inducing B cell activation as were low density dendritic and macrophage-enriched cells. Lymph node T cells freshly taken from antigen-primed animals were also found to proliferate when cultured with purified B cells and the appropriate antigen. Thus, small resting B cells can function as APC to a variety of T cells. This APC function was easily measured when the cells were irradiated with 1,000 rads, but was greatly diminished or absent when they were irradiated with 3,300 rads. Thus, the failure of some other laboratories to observe this phenomenon may be the result of the relative radiosensitivity of the antigen-presenting function of the B cells. In addition, this radiosensitivity allowed us to easily distinguish B cell antigen presentation from presentation by the dendritic cell and macrophage, as the latter was resistant to 3,300 rads. Finally, one T cell clone that failed to proliferate when B cells were used as APC was able to recruit allogeneic B cells to proliferate in the presence of syngeneic B cells and the appropriate antigen. This result suggests that there are at least two distinct pathways of activation in T cells, one that leads to T cell proliferation and one that leads to the secretion of B cell recruitment factor(s).

scholarly journals Interleukin 4 Reduces Expression of Inhibitory Receptors on B Cells and Abolishes CD22 and FcγRII-mediated B Cell Suppression

2002 ◽  
Vol 195 (8) ◽  
pp. 1079-1085 ◽  
Author(s):  
Elizabeth U. Rudge ◽  
Antony J. Cutler ◽  
Nicholas R. Pritchard ◽  
Kenneth G.C. Smith
Keyword(s):  
Immune Response ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Interleukin 4 ◽  
Cell Immune Response ◽  
B Cell Activation ◽  
Inhibitory Receptors ◽  
T Cell Help

Inhibitory receptors CD22, FcγRII (CD32), CD72, and paired immunoglobulin-like receptor (PIR)-B are critically involved in negatively regulating the B cell immune response and in preventing autoimmunity. Here we show that interleukin 4 (IL-4) reduces expression of all four on activated B cells at the level of messenger RNA and protein. This reduced expression is dependent on continuous exposure to IL-4 and is mediated through Stat6. Coligation of FcγRII to the B cell receptor (BCR) via intact IgG increases the B cell activation threshold and suppresses antigen presentation. IL-4 completely abolishes these negative regulatory effects of FcγRII. CD22 coligation with the BCR also suppresses activation — this suppression too is abolished by IL-4. Thus, IL-4 is likely to enhance the B cell immune response by releasing B cells from inhibitory receptor suppression. By this coordinate reduction in expression of inhibitory receptors, and release from CD22 and FcγRII-mediated inhibition, IL-4 is likely to play a role in T cell help of B cells and the development of T helper cell type 2 responses. Conversely, B cell activation in the absence of IL-4 would be more difficult to achieve, contributing to the maintenance of B cell tolerance in the absence of T cell help.

scholarly journals Effects of Friend Virus Infection and Regulatory T Cells on the Antigen Presentation Function of B Cells

mBio ◽  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Tyler C. Moore ◽  
Ronald J. Messer ◽  
Lorena M. Gonzaga ◽  
Jennifer M. Mather ◽  
Aaron B. Carmody ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Regulatory T Cells ◽  
B Cell ◽  
Cell Activation ◽  
T Cell Responses ◽  
B Cell Activation ◽  
Friend Virus ◽  
Cell Responses

ABSTRACTFriend virus (FV) is a naturally occurring mouse retrovirus that infects dividing cells of the hematopoietic lineage, including antigen-presenting cells (APCs). The infection of APCs by viruses often induces their dysfunction, and it has been shown that FV infection reduces the ability of dendritic cells (DCs) to prime critical CD8+T cell responses. Nonetheless, mice mount vigorous CD8+T cell responses, so we investigated whether B cells might serve as alternative APCs during FV infection. Directex vivoanalysis of B cells from FV-infected mice revealed that infected but not uninfected B cells upregulated expression of the costimulatory molecules CD80, CD86, and CD40, as well as major histocompatibility complex class II (MHC-II) molecules. Furthermore,in vitrostudies showed that, compared to uninfected B cells from the same mice, the FV-infected B cells had significantly enhanced APC function, as measured by their capacity to prime CD8+T cell activation and proliferation. Thus, in contrast to DCs, infection of B cells with FV enhanced their APC capacity and ability to stimulate the CD8+T cell responses essential for virus control. FV infections also induce the activation and expansion of regulatory T cells (Tregs), so it was of interest to determine the impact of Tregs on B cell activation. The upregulation of costimulatory molecule expression and APC function of B cells was even more strongly enhanced byin vivodepletion of regulatory T cells than infection. Thus, Tregs exert potent homeostatic suppression of B cell activation that is partially overcome by FV infection.IMPORTANCEThe primary role of B cells in immunity is considered the production of pathogen-specific antibodies, but another, less-well-studied, function of B cells is to present foreign antigens to T cells to stimulate their activation and proliferation. Dendritic cells (DCs) are considered the most important antigen-presenting cells (APCs) for CD8+T cells, but DCs lose APC function when infected with Friend virus (FV), a model retrovirus of mice. Interestingly, B cells were better able to stimulate CD8+T cell responses when they were infected with FV. We also found that the activation status of B cells under homeostatic conditions was potently modulated by regulatory T cells. This study illustrates an important link between B cell and T cell responses and illustrates an additional mechanism by which regulatory T cells suppress critical T cell responses during viral infections.

scholarly journals Induction of Peripheral T Cell Tolerance by Antigen-Presenting B Cells. II. Chronic Antigen Presentation Overrules Antigen-Presenting B Cell Activation

2006 ◽  
Vol 176 (7) ◽  
pp. 4021-4028 ◽  
Author(s):  
Giorgio Raimondi ◽  
Ivan Zanoni ◽  
Stefania Citterio ◽  
Paola Ricciardi-Castagnoli ◽  
Francesca Granucci
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Antigen Presentation ◽  
Cell Activation ◽  
T Cell Tolerance ◽  
Cell Tolerance ◽  
B Cell Activation ◽  
Antigen Presenting

scholarly journals Activation and Tolerance in CD4+ T Cells Reactive to an Immunoglobulin Variable Region

2004 ◽  
Vol 200 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Christopher M. Snyder ◽  
Katja Aviszus ◽  
Ryan A. Heiser ◽  
Daniel R. Tonkin ◽  
Amanda M. Guth ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Variable Region ◽  
Cell Receptor ◽  
B Cell Activation ◽  
Antibody Diversity ◽  
Helper Activity

Antibody diversity creates an immunoregulatory challenge for T cells that must cooperate with B cells, yet discriminate between self and nonself. To examine the consequences of T cell reactions to the B cell receptor (BCR), we generated a transgenic (Tg) line of mice expressing a T cell receptor (TCR) specific for a κ variable region peptide in monoclonal antibody (mAb) 36-71. The κ epitope was originally generated by a pair of somatic mutations that arose naturally during an immune response. By crossing this TCR Tg mouse with mice expressing the κ chain of mAb 36-71, we found that κ-specific T cells were centrally deleted in thymi of progeny that inherited the κTg. Maternally derived κTg antibody also induced central deletion. In marked contrast, adoptive transfer of TCR Tg T cells into κTg recipients resulted in T and B cell activation, lymphadenopathy, splenomegaly, and the production of IgG antichromatin antibodies by day 14. In most recipients, autoantibody levels increased with time, Tg T cells persisted for months, and a state of lupus nephritis developed. Despite this, Tg T cells appeared to be tolerant as assessed by severely diminished proliferative responses to the Vκ peptide. These results reveal the importance of attaining central and peripheral T cell tolerance to BCR V regions. They suggest that nondeletional forms of T tolerance in BCR-reactive T cells may be insufficient to preclude helper activity for chromatin-reactive B cells.

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