scholarly journals 3BP2 Deficiency Impairs the Response of B Cells, but Not T Cells, to Antigen Receptor Ligation

2006 ◽  
Vol 26 (14) ◽  
pp. 5214-5225 ◽  
Author(s):  
Miguel A. de la Fuente ◽  
Lalit Kumar ◽  
Bao Lu ◽  
Raif S. Geha
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Cycle Progression ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Normal Numbers ◽  
Tcr Signaling ◽  
And Function

ABSTRACT The adapter protein 3BP2 is expressed in lymphocytes; binds to Syk/ZAP-70, Vav, and phospholipase C-γ (PLC-γ); and is thought to be important for interleukin-2 gene transcription in T cells. To define the role of 3BP2 in lymphocyte development and function, we generated 3BP2-deficient mice. T-cell development, proliferation, cytokine secretion, and signaling in response to T-cell receptor (TCR) ligation were all normal in 3BP2−/− mice. 3BP2−/− mice had increased accumulation of pre-B cells in the bone marrow and a block in the progression of transitional B cells in the spleen from the T1 to the T2 stage, but normal numbers of mature B cells. B-cell proliferation, cell cycle progression, PLC-γ2 phosphorylation, calcium mobilization, NF-ATp dephosphorylation, and Erk and Jnk activation in response to B-cell receptor (BCR) ligation were all impaired. These results suggest that 3BP2 is important for BCR, but not for TCR signaling.

scholarly journals Comparative analysis of B7-1 and B7-2 costimulatory ligands: expression and function.

1994 ◽  
Vol 180 (2) ◽  
pp. 631-640 ◽  
Author(s):  
K S Hathcock ◽  
G Laszlo ◽  
C Pucillo ◽  
P Linsley ◽  
R J Hodes
Keyword(s):  
T Cell ◽  
B Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Interleukin 2 ◽  
Cell Types ◽  
Cell Receptor ◽  
Costimulatory Molecules ◽  
Tcr Signaling ◽  
And Function

Antigen-specific T cell activation requires the engagement of the T cell receptor (TCR) with antigen as well as the engagement of appropriate costimulatory molecules. The most extensively characterized pathway of costimulation has been that involving the interaction of CD28 and CTLA4 on the T cell with B7 (now termed B7-1) on antigen presenting cells. Recently, B7-2 a second costimulatory ligand for CTLA4, was described, demonstrating the potential complexity of costimulatory interactions. This report examines and compares the expression and function of B7-1 and B7-2. Overall these results indicate that (a) B7-1 and B7-2 can be expressed by multiple cell types, including B cells, T cells, macrophages, and dendritic cells, all of which are therefore candidate populations for delivering costimulatory signals mediated by these molecules; (b) stimulating B cells with either LPS or anti-IgD-dextran induced expression of both B7-1 and B7-2, and peak expression of both costimulatory molecules occurred after 18-42 h of culture. Expression of B7-2 on these B cell populations was significantly higher than expression of B7-1 at all times assayed after stimulation; (c) blocking of B7-2 costimulatory activity inhibited TCR-dependent T cell proliferation and cytokine production, without affecting early consequences of TCR signaling such as induction of CD69 or interleukin 2 receptor alpha (IL-2R alpha); and (d) expression of B7-1 and of B7-2 can be regulated by a variety of stimuli. Moreover, expression of B7-1 and B7-2 can be independently regulated by the same stimulus, providing an additional complexity in the mechanisms available for regulating costimulation and hence immune response.

scholarly journals SILAC phosphoproteomics reveals unique signaling circuits in CAR-T cells and the inhibition of B cell-activating phosphorylation in target cells

2021 ◽  
Author(s):  
Alijah A. Griffith ◽  
Kenneth P. Callahan ◽  
Nathan Gordo King ◽  
Qian Xiao ◽  
Xiaolei Su ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Receptor ◽  
Target Cells ◽  
Tcr Signaling ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

AbstractChimeric antigen receptor (CAR) is a single-pass transmembrane receptor designed to specifically target and eliminate cancers. While CARs prove highly efficacious against B cell malignancies, the intracellular signaling events which promote CAR T cell activity remain elusive. To gain further insight into both CAR T cell signaling and the potential signaling response of cells targeted by CAR, we analyzed phosphopeptides captured by two separate phopshoenrichment strategies from third generation CD19-CAR T cells cocultured with SILAC labeled Raji B cells by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Here, we report that CD19-CAR T cells upregulated several key phosphorylation events also observed in canonical T cell receptor (TCR) signaling while Raji B cells exhibited a significant decrease in B cell receptor-signaling related phosphorylation events in response to coculture. Our data suggest that CD19-CAR stimulation activates a mixture of unique CD19-CAR-specific signaling pathways and canonical TCR signaling while global phosphorylation in Raji B cells is reduced after association with the CD19-CAR T cells.

Ig alpha and Ig beta are functionally homologous to the signaling proteins of the T-cell receptor

1994 ◽  
Vol 14 (2) ◽  
pp. 1095-1103
Author(s):  
A L Burkhardt ◽  
T Costa ◽  
Z Misulovin ◽  
B Stealy ◽  
J B Bolen ◽  
...  
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Receptor ◽  
Interleukin 2 ◽  
Antigen Receptor ◽  
Cell Receptor ◽  
Antigen Receptors ◽  
Cell Antigen

Signal transduction by antigen receptors and some Fc receptors requires the activation of a family of receptor-associated transmembrane accessory proteins. One common feature of the cytoplasmic domains of these accessory molecules is the presence is at least two YXXA repeats that are potential sites for interaction with Src homology 2 domain-containing proteins. However, the degree of similarity between the different receptor-associated proteins varies from that of T-cell receptor (TCR) zeta and Fc receptor RIIIA gamma chains, which are homologous, to the distantly related Ig alpha and Ig beta proteins of the B-cell antigen receptor. To determine whether T- and B-cell antigen receptors are in fact functionally homologous, we have studied signal transduction by chimeric immunoglobulins bearing the Ig alpha or Ig beta cytoplasmic domain. We found that Ig alpha and Ig beta cytoplasmic domains were able to activate Ca2+ flux, interleukin-2 secretion, and phosphorylation of the same group of cellular substrates as the TCR in transfected T cells. Chimeric proteins were then used to examine the minimal requirements for activation of the Fyn, Lck, and ZAP kinases in T cells. Both Ig alpha and Ig beta were able to trigger Fyn, Lck, and ZAP directly without involvement of TCR components. Cytoplasmic tyrosine residues in Ig beta were required for recruitment and activation of ZAP-70, but these amino acids were not essential for the activation of Fyn and Lck. We conclude that Fyn and Lck are able to recognize a clustered nonphosphorylated immune recognition receptor, but activation of these kinases is not sufficient to induce cellular responses such as Ca2+ flux and interleukin-2 secretion. In addition, the molecular structures involved in antigen receptor signaling pathways are conserved between T and B cells.

scholarly journals Loss of tonic T-cell receptor signals alters the generation but not the persistence of CD8+ memory T cells

Blood ◽  
2010 ◽  
Vol 116 (25) ◽  
pp. 5560-5570 ◽  
Author(s):  
Karla R. Wiehagen ◽  
Evann Corbo ◽  
Michelle Schmidt ◽  
Haina Shin ◽  
E. John Wherry ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Lymphocytic Choriomeningitis ◽  
Sh2 Domain ◽  
Normal Numbers ◽  
Tcr Signaling ◽  
Tcr Signals

Abstract The requirements for tonic T-cell receptor (TCR) signaling in CD8+ memory T-cell generation and homeostasis are poorly defined. The SRC homology 2 (SH2)-domain–containing leukocyte protein of 76 kDa (SLP-76) is critical for proximal TCR-generated signaling. We used temporally mediated deletion of SLP-76 to interrupt tonic and activating TCR signals after clearance of the lymphocytic choriomeningitis virus (LCMV). SLP-76–dependent signals are required during the contraction phase of the immune response for the normal generation of CD8 memory precursor cells. Conversely, LCMV-specific memory CD8 T cells generated in the presence of SLP-76 and then acutely deprived of TCR-mediated signals persist in vivo in normal numbers for more than 40 weeks. Tonic TCR signals are not required for the transition of the memory pool toward a central memory phenotype, but the absence of SLP-76 during memory homeostasis substantially alters the kinetics. Our data are consistent with a model in which tonic TCR signals are required at multiple stages of differentiation, but are dispensable for memory CD8 T-cell persistence.

scholarly journals Interleukin 2 induces antigen-reactive T cell lines to secrete BCGF-I.

1983 ◽  
Vol 158 (6) ◽  
pp. 2024-2039 ◽  
Author(s):  
M Howard ◽  
L Matis ◽  
T R Malek ◽  
E Shevach ◽  
W Kell ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Line ◽  
Cell Lines ◽  
Interleukin 2 ◽  
Activated T Lymphocytes ◽  
T Cell Lines ◽  
Activated B Cells

Antigen-activated T lymphocytes produce within 24 h of stimulation a factor that is indistinguishable biochemically and functionally from the B cell co-stimulating growth factor, BCGF-I, originally identified in induced EL4 supernatants: Supernatants from antigen-stimulated T cell lines are not directly mitogenic for resting B cells, but synergize in an H-2-unrestricted manner with anti-Ig activated B cells to produce polyclonal proliferation but not antibody-forming-cell development; biochemical studies reveal the B cell co-stimulating factor present in antigen-stimulated T cell line supernatants is identical by phenyl Sepharose chromatography and isoelectric focusing (IEF) to EL4 supernatant BCGF-I. We thus conclude that normal T cells produce BCGF-I in response to antigenic stimulation. Analysis of the mechanism of BCGF-I production by antigen-stimulated T cells showed that optimum amounts of BCGF-I were obtained as quickly as 24 h post-stimulation, and that the factor producing cells in the T cell line investigated bore the Lyt-1+2- phenotype. As few as 10(4) T cells produced sufficient BCGF-I to support the proliferation of 5 X 10(4) purified anti-Ig activated B cells. Finally, the activation of normal T cell lines to produce BCGF-I required either antigen presented in the context of syngeneic antigen-presenting cells (APC) or interleukin 2 (IL-2).

Flexible migration program regulates γδ T-cell involvement in humoral immunity

Blood ◽  
2003 ◽  
Vol 102 (10) ◽  
pp. 3693-3701 ◽  
Author(s):  
Marlène Brandes ◽  
Katharina Willimann ◽  
Alois B. Lang ◽  
Ki-Hoan Nam ◽  
Chenggang Jin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Humoral Immunity ◽  
Γδ T Cells ◽  
Cell Receptor ◽  
Lymphoid Tissues ◽  
Migration Program ◽  
And Function

Abstractγδ T cells are inadequately defined both in terms of their migration potential and contribution to antimicrobial immunity. Here, we have examined the migration profile of human blood γδ T cells and related cell lines and correlated these findings with their distribution in secondary lymphoid tissues and their function in B-cell cocultures. We find that resting γδ T cells are characterized by an inflammatory migration program similar to cells of the innate immune system. However, T-cell receptor (TCR) triggering resulted in the rapid but transient induction of a lymph node (LN)-homing program, as evidenced by functional CCR7 expression and concomitant reduction in expression and function of CCR5 and, to a lesser degree, CCR2. Moreover, the LN-homing program was reflected by the presence of γδ T cells in gastrointestinal lymphoid tissues, notably in clusters within germinal centers of B-cell follicles. In line with these findings, VγVδ-TCR triggering resulted in prominent expression of essential B-cell costimulatory molecules, including CD40L, OX40, CD70, and ICOS. Furthermore, γδ T cells were shown to provide potent B-cell help during in vitro antibody production. Collectively, our findings agree with a role for γδ T cells in humoral immunity during the early phase of antimicrobial responses. (Blood. 2003; 102:3693-3701)

scholarly journals Spontaneous relapsing-remitting EAE in the SJL/J mouse: MOG-reactive transgenic T cells recruit endogenous MOG-specific B cells

2009 ◽  
Vol 206 (6) ◽  
pp. 1303-1316 ◽  
Author(s):  
Bernadette Pöllinger ◽  
Gurumoorthy Krishnamoorthy ◽  
Kerstin Berer ◽  
Hans Lassmann ◽  
Michael R. Bösl ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Transgenic Mice ◽  
B Cell ◽  
Cell Receptor ◽  
Conformational Epitope ◽  
Autoreactive B Cells ◽  
Spinal Cord Development ◽  
Relapsing Remitting

We describe new T cell receptor (TCR) transgenic mice (relapsing-remitting [RR] mice) carrying a TCR specific for myelin oligodendrocyte glycoprotein (MOG) peptide 92–106 in the context of I-As. Backcrossed to the SJL/J background, most RR mice spontaneously develop RR experimental autoimmune encephalomyelitis (EAE) with episodes often altering between different central nervous system tissues like the cerebellum, optic nerve, and spinal cord. Development of spontaneous EAE depends on the presence of an intact B cell compartment and on the expression of MOG autoantigen. There is no spontaneous EAE development in B cell–depleted mice or in transgenic mice lacking MOG. Transgenic T cells seem to expand MOG autoreactive B cells from the endogenous repertoire. The expanded autoreactive B cells produce autoantibodies binding to a conformational epitope on the native MOG protein while ignoring the T cell target peptide. The secreted autoantibodies are pathogenic, enhancing demyelinating EAE episodes. RR mice constitute the first spontaneous animal model for the most common form of multiple sclerosis (MS), RR MS.

scholarly journals Unc119, a Novel Activator of Lck/Fyn, Is Essential for T Cell Activation

2004 ◽  
Vol 199 (3) ◽  
pp. 369-379 ◽  
Author(s):  
Magdalena M. Gorska ◽  
Susan J. Stafford ◽  
Osman Cen ◽  
Sanjiv Sur ◽  
Rafeul Alam
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cellular Proliferation ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
The Novel ◽  
Tcr Signaling ◽  
Src Homology

The first step in T cell receptor for antigen (TCR) signaling is the activation of the receptor-bound Src kinases, Lck and Fyn. The exact mechanism of this process is unknown. Here, we report that the novel Src homology (SH) 3/SH2 ligand–Uncoordinated 119 (Unc119) associates with CD3 and CD4, and activates Lck and Fyn. Unc119 overexpression increases Lck/Fyn activity in T cells. In Unc119-deficient T cells, Lck/Fyn activity is dramatically reduced with concomitant decrease in interleukin 2 production and cellular proliferation. Reconstitution of cells with Unc119 reverses the signaling and functional outcome. Thus, Unc119 is a receptor-associated activator of Src-type kinases. It provides a novel mechanism of signal generation in the TCR complex.

scholarly journals T Cell Receptor–initiated Calcium Release Is Uncoupled from Capacitative Calcium Entry in Itk-deficient T Cells

1998 ◽  
Vol 187 (10) ◽  
pp. 1721-1727 ◽  
Author(s):  
Karen-Qianye Liu ◽  
Stephen C. Bunnell ◽  
Christine B. Gurniak ◽  
Leslie J. Berg
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Calcium Release ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Calcium Entry ◽  
Tcr Signaling ◽  
Store Depletion ◽  
High Concentrations

Itk, a Tec family tyrosine kinase, plays an important but as yet undefined role in T cell receptor (TCR) signaling. Here we show that T cells from Itk-deficient mice have a TCR-proximal signaling defect, resulting in defective interleukin 2 secretion. Upon TCR stimulation, Itk−/− T cells release normal amounts of calcium from intracellular stores, but fail to open plasma membrane calcium channels. Since thapsigargin-induced store depletion triggers normal calcium entry in Itk−/− T cells, an impaired biochemical link between store depletion and channel opening is unlikely to be responsible for this defect. Biochemical studies indicate that TCR-induced inositol 1,4,5 tris-phosphate (IP3) generation and phospholipase C γ1 tyrosine phosphorylation are substantially reduced in Itk−/− T cells. In contrast, TCR-ζ and ZAP-70 are phosphorylated normally, suggesting that Itk functions downstream of, or in parallel to, ZAP-70 to facilitate TCR-induced IP3 production. These findings support a model in which quantitative differences in cytosolic IP3 trigger distinct responses, and in which only high concentrations of IP3 trigger the influx of extracellular calcium.

scholarly journals The Tigit/CD226/CD155 Immunomodulatory Axis Is Deregulated in CLL and Contributes to B-Cell Anergy

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3718-3718
Author(s):  
Francesca Arruga ◽  
Andrea Iannello ◽  
Nikolaos Ioannou ◽  
Alberto Maria Todesco ◽  
Marta Coscia ◽  
...  
Keyword(s):  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Cell Receptor ◽  
Tcr Signaling ◽  
Advisory Committees ◽  
Cell Responses ◽  
Blocking Antibodies

Abstract BACKGROUND. T cell immunoreceptor with Ig and ITIM domains (TIGIT) is an inhibitory receptor expressed on T, NK and NKT cells, sharing structural and mechanistic similarities with PD-1 and CTLA-4. TIGIT competes with CD226, its partner receptor, for the binding to CD155 ligand: signaling triggered upon CD155 binding to CD226 potentiates T cell receptor (TCR) signaling and CD8 + T cell cytotoxicity against tumor cells (positive signaling). On the contrary, concomitant TIGIT expression on the cell surface prevents CD226 activation either by sequestering CD155 or by impeding CD226 homodimerization and phosphorylation (negative signaling). Recently, TIGIT was shown to be expressed on the surface of normal memory B cells, where it could directly act to suppress T cell responses. No data are available on TIGIT or CD226 expression by chronic lymphocytic leukemia (CLL) cells. AIM AND METHODS. Our aim was to investigate expression of the TIGIT and CD226 receptors and of the CD155 ligand in a cohort of clinically and molecularly annotated CLL patient samples. To this end, we designed a multiparametric panel of antibodies for flow cytometry and examined expression of the TIGIT/CD226/CD155 axis in peripheral blood mononuclear cells (PBMC) from our patient cohort. To investigate the impact of TIGIT/CD226 engagement on B cell responses, purified leukemic B cells were activated either through the B cell receptor (BCR) using an αIgM polyclonal antibody or with CpG oligonucleotide and interleukin 15 (IL-15) to induce proliferation. In selected experiments, we added recombinant human (Rh) TIGIT-Fc or CD155-Fc chimeras and αTIGIT or αCD226 blocking antibodies to interfere with this axis. RESULTS. Surface expression of TIGIT, CD226 and CD155 was evaluated in a cohort of 115 CLL samples and compared to age- and sex-matched healthy subjects. Both TIGIT and CD226 were upregulated on leukemic B cells compared to normal B lymphocytes, while CD155 was expressed at lower levels. A similar trend was observed on CD4 + and CD8 + T lymphocytes. High-risk CLLs (unmutated IgV genes, unfavorable cytogenetics and advanced stage) were predominantly TIGIT low and CD226 high, indicating an unbalance towards "positive signaling". Results were confirmed by confocal microscopy analyses on lymph node (LN) biopsies, which showed i) an overall higher TIGIT expression in CLL compared to reactive LNs and ii) among CLL LNs a stronger TIGIT positivity in mutated vs unmutated cases, confirming flow cytometry data. In line with these findings, Richter's syndrome samples and patient-derived xenografts models showed the lowest TIGIT and the highest CD226 levels. We next examined TIGIT axis expression during the follow up of CLL cases who underwent treatment with BTK inhibitor (BTKi). While CD226 levels remained unmodified upon treatment, a sharp decrease in surface TIGIT was detected soon after BTKi initiation. Since TIGIT acts by decreasing TCR signaling to shut down T cell responses, we hypothesized similar functions in B cells. By crosslinking the BCR with an αIgM antibody in a selected cohort of IGHV UM CLL cells, we found that BTK phosphorylation was induced to a lesser extent in TIGIT high compared to TIGIT low samples, suggesting that TIGIT is a marker of CLL cell anergy. Accordingly, interruption of receptors/ligand interactions with RhTIGIT-Fc chimera or with αTIGIT or αCD226 blocking antibodies, modulated BCR signaling capacity. Specifically, in TIGIT high samples, preventing receptor engagement by CD155 increased αIgM-induced BTK phosphorylation; in contrast, in TIGIT low samples, blocking CD155 interaction affected mostly CD226 signaling, thereby depotentiating BCR activation. Similar results were obtained when stimulating CLL cells with CpG/IL-15. Interestingly, we observed a significant upregulation of surface CD226 in CLL cells cultured for 6 days in the presence of CpG/IL-15. CONCLUSIONS. These results show for the first-time expression of TIGIT by CLL cells. Furthermore, they indicate that TIGIT is a marker of CLL cells anergy, whereas activated CLL cells express high levels of CD226. Inhibition of TIGIT binding to CD155 partially restores B cell signaling and activation. Future studies are needed to gain insights on the mechanisms behind its deregulation and to obtain a complete functional characterization of the axis. Disclosures Coscia: AbbVie: Honoraria, Other; Janssen: Honoraria, Other, Research Funding; AstraZeneca: Honoraria; Gilead: Honoraria. Gaidano: Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astrazeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Beigene: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Allan: Genentech: Consultancy, Research Funding; Epizyme: Consultancy; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria; BeiGene: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Celegene: Research Funding; AstraZeneca Pharmaceuticals LP, Genentech, a member of the Roche Group, Janssen Biotech Inc, TG Therapeutics Inc.: Research Funding; AbbVie Inc, AstraZeneca Pharmaceuticals LP, BeiGene, Janssen Biotech Inc, Pharmacyclics LLC: Consultancy; AbbVie Inc, Ascentage Pharma, Epizyme, Genentech, a member of the Roche Group, Janssen Biotech Inc, Pharmacyclics LLC: Other: Advisory Committee; TG Therapeutics: Research Funding. Furman: Oncotracker: Consultancy; Verastem: Consultancy; Abbvie: Consultancy, Honoraria, Other: Expert testimony; Sunesis: Consultancy; Incyte: Consultancy; Beigene: Consultancy; Acerta/AstraZeneca: Consultancy; Loxo Oncology: Consultancy; Genentech: Consultancy; Morphosys: Consultancy; Pharmacyclics: Consultancy; Sanofi: Consultancy; TG Therapeutics: Consultancy; X4 Pharmaceuticals: Consultancy; Janssen: Consultancy, Honoraria; AstraZeneca: Honoraria. Deaglio: Heidelberg Pharma: Research Funding; Astra Zeneca: Research Funding.

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