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.

Pre-Clinical Characterization of T Cell-Dependent Bispecific Antibody Anti-CD79b/CD3 As a Potential Therapy for B Cell Malignancies

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4507-4507 ◽  
Author(s):  
L. Laura Sun ◽  
Xiaocheng Chen ◽  
Yvonne Chen ◽  
Mark S. Dennis ◽  
Diego Ellerman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cell Receptor ◽  
Antibody Fragments ◽  
Bispecific Antibodies ◽  
Cell Targeting ◽  
B Cell Malignancies

Abstract T-cell recruiting bispecific antibodies and antibody fragments have been used to harness the cytotoxic potential of T cells for cancer treatment. As an example, encouraging clinical responses have been reported with the B cell targeting Blinatumomab, a 55-kDa fusion protein composed of two single-chain antibody fragments (scFvs). However, the therapeutic promise of many reported bispecific antibodies and fragments is often limited by unfavorable pharmacokinetics and administration schedule, immunogenicity, and a propensity towards aggregation. We have adopted a knobs-into-holes (KIH) antibody format and produced T-cell dependent bispecific antibodies (TDB), which allow one arm to target various B cell antigens while the other arm recruits T cells by binding to the CD3e subunit of the T-cell receptor. These B cell targeting TDBs are full length, humanized IgG1 antibodies with natural antibody architecture. Single dose pharmacokinetic/pharmacodynamic studies in cynomolgus monkeys show the KIH format TDBs are well tolerated in life, result in potent B cell depletion in peripheral and lymphoid tissue, and demonstrate pharmacokinetic properties resembling conventional antibody therapy. One B cell antigen targeted is CD79b, a component of the B cell receptor complex. CD79b is restricted to B cells, is highly prevalent on B cell leukemia and lymphomas, and has been clinically validated by an anti-CD79b antibody-drug conjugate as a safe and effective therapeutic target for B cell malignancies (ASCO 2014 abstract#8519). In our present work, we show that anti-CD79b/CD3 TDB can be produced and purified from E.coli, free of homodimer and aggregates. Anti-CD79b/CD3 TDB is a conditional agonist, activating CD3+T cells only in the presence of CD79b expressing B cells. In vitro, it induces potent B cell killing in a T-cell dependent manner, and is broadly active against lymphoma cell lines with a wide range of CD79b antigen levels. Compared to bispecific antibodies targeting some other B cell antigens, anti-CD79b/CD3 TDB appears to be more potent in autologous B cell killing assays with human PBMCs isolated from healthy donors. Taking advantage of antibodies with a range of binding affinities, we show that the B cell cytotoxic potency of anti-CD79b/CD3 TDB can be enhanced with increased binding affinity of either the anti-CD79b arm or the anti-CD3 arm in vitro. To assess the therapeutic potential of anti-CD79b/CD3 TDB, we further demonstrate that it is active in killing B lymphoma cells isolated from leukemia and lymphoma patients. Collectively, these preclinical data suggest anti-CD79b/CD3 TDB may be a promising agent for clinical development in B cell malignancies. Disclosures Sun: Genentech: Employment. Chen:Genentech: Employment. Chen:Genentech: Employment. Dennis:Genentech: Employment. Ellerman:Genentech: Employment. Johnson:Genentech: Employment. Mathieu:Genentech: Employment. Oldendorp:Genentech: Employment. Polson:Genentech: Employment. Reyes:Genentech: Employment. Stefanich:Genentech: Employment. Wang:Genentech: Employment. Wang:Genentech: Employment. Zheng:Genentech: Employment. Ebens:Genentech: Employment.

scholarly journals Antibody-mediated B-cell depletion before adoptive immunotherapy with T cells expressing CD20-specific chimeric T-cell receptors facilitates eradication of leukemia in immunocompetent mice

Blood ◽  
2009 ◽  
Vol 114 (27) ◽  
pp. 5454-5463 ◽  
Author(s):  
Scott E. James ◽  
Nural N. Orgun ◽  
Thomas F. Tedder ◽  
Mark J. Shlomchik ◽  
Michael C. Jensen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Transgenic Mice ◽  
B Cell ◽  
T Cell Receptors ◽  
Adoptive T Cell Therapy ◽  
Cell Depletion ◽  
B Cell Depletion ◽  
Cell Receptors

Abstract We have established a model of leukemia immunotherapy using T cells expressing chimeric T-cell receptors (cTCRs) targeting the CD20 molecule expressed on normal and neoplastic B cells. After transfer into human CD20 (hCD20) transgenic mice, cTCR+ T cells showed antigen-specific delayed egress from the lungs, concomitant with T-cell deletion. Few cTCR+ T cells reached the bone marrow (BM) in hCD20 transgenic mice, precluding effectiveness against leukemia. Anti-hCD20 antibody-mediated B-cell depletion before adoptive T-cell therapy permitted egress of mouse CD20-specific cTCR+ T cells from the lungs, enhanced T-cell survival, and promoted cTCR+ T cell–dependent elimination of established mouse CD20+ leukemia. Furthermore, CD20-specific cTCR+ T cells eliminated residual B cells refractory to depletion with monoclonal antibodies. These findings suggest that combination of antibody therapy that depletes antigen-expressing normal tissues with adoptive T-cell immunotherapy enhances the ability of cTCR+ T cells to survive and control tumors.

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 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.

scholarly journals B cell function in mice transgenic for mCTLA4-H gamma 1: lack of germinal centers correlated with poor affinity maturation and class switching despite normal priming of CD4+ T cells.

1994 ◽  
Vol 179 (3) ◽  
pp. 819-830 ◽  
Author(s):  
P Lane ◽  
C Burdet ◽  
S Hubele ◽  
D Scheidegger ◽  
U Müller ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Transgenic Mice ◽  
B Cell ◽  
Germinal Center ◽  
Cd4 T Cells ◽  
Class Switching ◽  
T Cell Help ◽  
Germinal Center Formation

This report outlines the B cell phenotype of transgenic mice that overexpresses the mouse CTLA-4-human gamma 1 (mCTLA4-H gamma 1) protein. Despite the fact that these mice prime CD4+ T cells (Ronchese, F., B. Housemann, S. Hubele, and P. Lane. 1994. J. Exp. Med. 179:809), antibody responses to T-dependent antigens are severely impaired. In contrast, T-independent responses are normal which suggests mCTLA4-H gamma 1 does not act directly on B cells, but acts indirectly by impairing T cell help. The impaired antibody defect is associated with impaired class switching, with low total immunoglobulin (Ig)G and antigen-specific IgG responses, and an absence of germinal center formation in spleen and lymph nodes but not gut-associated tissues. The defective germinal center formation is associated with a reduction in the degree of somatic mutation in hybridomas made from transgenic mice in comparison with those made from normal mice. It seems likely that mCTLA4-H gamma 1 exerts its effect by blocking an interaction between T and B cells that induce T cell help for B cells.

scholarly journals Human Non-Germinal Center B Cell Interleukin (IL)-12 Production Is Primarily Regulated by T Cell Signals CD40 Ligand, Interferon γ, and IL-10: Role of B Cells in the Maintenance of  T Cell Responses

1999 ◽  
Vol 189 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Joachim L. Schultze ◽  
Sabine Michalak ◽  
Joel Lowne ◽  
Adam Wong ◽  
Maria H. Gilleece ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Synergistic Effects ◽  
Cell Receptor ◽  
Cd40 Ligation ◽  
Cd40 Activation ◽  
Ifn Γ

Interleukin (IL)-12 is expressed mainly in antigen-presenting cells after challenge with microbial material or after CD40 activation. Although IL-12 was cloned from human Epstein-Barr virus (EBV)-transformed B cell lines, surprisingly, CD40 ligation on murine B cells did not lead to IL-12 production, suggesting that murine B cells do not produce IL-12. Here we demonstrate that a subset of human tonsillar B cells can be induced to express and secrete bioactive IL-12. The major stimulus to produce IL-12 in human B cells was CD40 ligation. In contrast, B cell receptor cross-linking did not induce IL-12. Expression of IL-12 after CD40 activation was restricted to CD38−IgD± non-germinal center (non-GC) B cells. CD40 ligation and interferon (IFN)-γ exhibited synergistic effects on IL-12 production, whereas IL-10 abrogated and IL-4 significantly inhibited IL-12 production by these B cells. In contrast to IL-12, production of IL-6 is conversely regulated, leading to significant increase after CD40 ligation in the presence of the T helper type 2 (Th2) cytokine IL-4. Cord blood T cells skewed towards either a Th1 or a Th2 phenotype maintained their cytokine expression pattern when restimulated with allogeneic resting B cells. Blockade of CD40 and/or IL-12 during T–B interaction significantly reduced IFN-γ production by the T cells. This suggests a model whereby B cells produce either IL-12 or IL-6 after contact with T cells previously differentiated towards Th1 or Th2. Furthermore, IL-12 and IL-6 might provide a positive feedback during cognate T–B interactions, thereby maintaining T cells' differentiation pattern during amplification of the immune response.

scholarly journals Ig-specific T cell receptor-transgenic T cells are not deleted in the thymus and are functional in vivo.

1996 ◽  
Vol 183 (1) ◽  
pp. 203-213 ◽  
Author(s):  
F Granucci ◽  
M Rescigno ◽  
G Marconi ◽  
M Foti ◽  
P Ricciardi-Castagnoli
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Transgenic Mice ◽  
Transgenic Mouse ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Cell Receptor Transgenic Mouse

The mechanisms that induce T cell tolerance to circulating self-proteins are still controversial, and both the deletion and selection of autoreactive T cells have been observed in the thymus of transgenic mouse models. To address the question of the induction of tolerance to circulating self-constituents, a T cell receptor-transgenic mouse specific for the serum protein immunoglobulin (Ig) gamma and (IgG2ab) was generated. The choice of an allotype-specific T cell also allowed the generation of transgenic control mice not expressing the self-antigen. It was found that the transgenic T cells were not deleted in the thymus, did not become tolerant in the periphery, and regulated the function of gamma 2ab-positive B cells as shown by the lack of IgG2ab protein in the serum of the transgenic mice. In spite of this activity in vivo, the transgenic T cells did not proliferate in vitro in response to the allotype-specific peptide. Interestingly, antigen-specific T cell proliferation could be restored if the transgenic mice were previously challenged to induce IgG2ab responses. After this challenge, IgG2ab protein in the serum of the transgenic mice could be partially restored, although still remaining much lower than in control mice. In addition, there was a dramatic increase in serum IgE levels, suggesting that newly generated gamma 2ab-secreting B cells can be induced to switch to IgE in the presence of allotype-specific T cells. These results indicate that Ig-specific T cells may represent a late-acting form of T cell help for the regulation of the IgG2a-to-IgE class switch.

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.

Clinical Significance of Free Circulating CD3 and CD5 in Patients with Chronic Lymphocytic Leukemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4947-4947
Author(s):  
Menna Hodge ◽  
Susan O’Brien ◽  
Adam Abdool ◽  
Michael Keating ◽  
Iman Jilani ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Normal Control ◽  
Cell Receptor ◽  
Lymphocytic Leukemia ◽  
Β2 Microglobulin ◽  
Control Subjects

Abstract </DEL> CD5, a transmembrane protein expressed in T-cells, few B-cells, and chronic lymphocytic leukemia (CLL) B-cells, is the ligand for CD72 and may play a role in B-cell-T-cell communication. CD5 is part of the T-cell receptor (TCR)-CD3 complex in T-cells as well as the B-cell receptor (BCR) complex and serves as substrate for induction of tyrosine kinase activity. Since leukemic cells have high turnover and pour their protein, RNA, and DNA into the circulation, we speculated that free circulating CD3 (cCD3) and CD5 (cCD5) could be detected in the plasma of patients with CLL. We have developed a bead-based sandwich immunoassay to measure cCD3 and cCD5 in the plasma. Using this assay, we assessed the value of cCD5 measurement, alone and after normalization to cCD3 levels, as a tumor marker in CLL. Plasma levels of cCD3 and cCD5 were measured in 85 patients with CLL and 51 normal control subjects. cCD3 and cCD5 levels were significantly higher in patients with CLL (median, 7,465 and 55,806 U/μl, respectively) than in normal control subjects (median, 830 and 1,671 U/μl, respectively). Patients with CLL had significantly higher cCD5:cCD3 ratios (median, 5.28; range, 0–161) than did normal controls (median, 1.70; range, 0–8.06) (P <0.0001). Levels of cCD5, but not cCD3, correlated positively with WBC count, β2-microglobulin level, splenomegaly, and Rai stage (all P <0.01). The cCD5:cCD3 ratio also correlated with Rai stage (P = 0.04) and β2-microglobulin level (P = 0.03). cCD5 levels and the cCD5:cCD3 ratio both correlated with survival (P = 0.03). These findings confirm that free circulating surface markers can be detected in the circulation of patients with CLL, most likely reflect the tumor load, and can be used as tumor markers. The biological and therapeutic relevance of these free circulating proteins should be considered in pharmacokinetic and pharmacodynamic studies.

scholarly journals Immune receptor repertoires in pediatric and adult acute myeloid leukemia

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian Zhang ◽  
Xihao Hu ◽  
Jin Wang ◽  
Avinash Das Sahu ◽  
David Cohen ◽  
...  
Keyword(s):  
T Cells ◽  
Acute Myeloid Leukemia ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Myeloid Leukemia ◽  
Myeloid Cells ◽  
Cell Receptor ◽  
Immune Receptor ◽  
Acute Myeloid

Abstract Background Acute myeloid leukemia (AML), caused by the abnormal proliferation of immature myeloid cells in the blood or bone marrow, is one of the most common hematologic malignancies. Currently, the interactions between malignant myeloid cells and the immune microenvironment, especially T cells and B cells, remain poorly characterized. Methods In this study, we systematically analyzed the T cell receptor and B cell receptor (TCR and BCR) repertoires from the RNA-seq data of 145 pediatric and 151 adult AML samples as well as 73 non-tumor peripheral blood samples. Results We inferred over 225,000 complementarity-determining region 3 (CDR3) sequences in TCR α, β, γ, and δ chains and 1,210,000 CDR3 sequences in B cell immunoglobulin (Ig) heavy and light chains. We found higher clonal expansion of both T cells and B cells in the AML microenvironment and observed many differences between pediatric and adult AML. Most notably, adult AML samples have significantly higher level of B cell activation and more secondary Ig class switch events than pediatric AML or non-tumor samples. Furthermore, adult AML with highly expanded IgA2 B cells, which might represent an immunosuppressive microenvironment, are associated with regulatory T cells and worse overall survival. Conclusions Our comprehensive characterization of the AML immune receptor repertoires improved our understanding of T cell and B cell immunity in AML, which may provide insights into immunotherapies in hematological malignancies.

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