Functional and Molecular Analysis of Maturation of Thymocytes in Bcl10 or Malt1 Deficient Mice.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3323-3323
Author(s):  
Philipp J. Jost ◽  
Uta Ferch ◽  
Stephanie Weiss ◽  
Stephanie Leeder ◽  
Olaf Gross ◽  
...  

Abstract Development of immature T cells in the thymus requires signals through the clonotypic T cell receptor (TCR). Thymocytes expressing a functionally inactive or autoreactive TCR are deleted via apoptosis (negative selection). Thymocytes expressing a functionally active but not autoreactive TCR are selected through inhibition of cell death (positive selection). Deregulation of this process is likely to result in autoimmunity or lymphomagenesis of T cells. The intracellular mechanisms by which the balance between TCR-dependent survival and apoptosis are regulated are largely unknown. A central regulator of survival and apoptosis in the immune system is the transcription factor NF-κB. Activation of NF-κB in mature T-cells requires the adaptor proteins Bcl10 and Malt1. Using gene-targeted mice deficient for Bcl10 or Malt1, we show that Bcl10 and Malt1 are also required for TCR-induced NF-κB activation in immature T cells. Furthermore, to elucidate the process of T cell selection within the thymus, we have crossed Bcl10 or Malt1 deficient mice into mice with genetic backgrounds expressing defined TCR transgenes. Using specific peptide agonists of these TCR transgenes, we show that neither in vivo nor in vitro development into single positive (SP) CD4 or CD8 positive T cells is altered in Bcl10 or Malt1 deficient mice. Absolute numbers and ratio of SP T cells found within the thymus or in peripheral lymphnodes of transgenic animals are normal. These findings indicate that Bcl10 and Malt1 activate NF-κB in thymocytes but are dispensable for maturation of immature T cells in this model system.

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A185-A185
Author(s):  
Michelle Fleury ◽  
Derrick McCarthy ◽  
Holly Horton ◽  
Courtney Anderson ◽  
Amy Watt ◽  
...  

BackgroundAdoptive cell therapies have shown great promise in hematological malignancies but have yielded little progress in the context of solid tumors. We have developed T cell receptor fusion construct (TRuC®) T cells, which are equipped with an engineered T cell receptor that utilizes the full complement of TCR signaling subunits and recognizes tumor-associated antigens independent of HLA. In clinical trials, mesothelin (MSLN)-targeting TRuC-T cells (TC-210 or gavo-cel) have shown unprecedented results in patients suffering from advanced mesothelioma and ovarian cancer. To potentially increase the depth of response, we evaluated strategies that can promote intra-tumoral T cell persistence and function. Among the common ??-chain cytokines, IL-15 uniquely supports the differentiation and maintenance of memory T cell subsets by limiting terminal differentiation and conferring resistance to IL-2 mediated activation-induced cell death (AICD). In the studies described here, we evaluated the potential of IL-15 as an enhancement to TRuC-T cell phenotype, persistence and function against MSLN+ targets.MethodsPrimary human T cells were activated and transduced with a lentiviral vector encoding an anti-MSLN binder fused to CD3ε alone or co-expressed with a membrane-tethered IL-15rα/IL-15 fusion protein (IL-15fu). Transduced T cells were expanded for 9 days and characterized for expression of the TRuC, IL-15rα and memory phenotype before subjecting them to in vitro functional assays to evaluate cytotoxicity, cytokine production, and persistence. In vivo efficacy was evaluated in MHC class I/II deficient NSG mice bearing human mesothelioma xenografts.ResultsIn vitro, co-expression of the IL-15fu led to similar cytotoxicity and cytokine production as TC-210, but notably enhanced T-cell expansion and persistence upon repeated stimulation with MSLN+ cell lines. Furthermore, the IL-15fu-enhanced TRuC-T cells sustained a significantly higher TCF-1+ population and retained a stem-like phenotype following activation. Moreover, the IL-15fu-enhanced TRuCs demonstrated robust in vivo expansion and intra-tumoral accumulation as measured by ex vivo analysis of TRuC+ cells in the tumor and blood, with a preferential expansion of CD8+ T cells. Finally, IL-15fu-enhanced TRuC-T cells could be observed in the blood long after the tumors were cleared.ConclusionsThese pre-clinical studies suggest that the IL-15fu can synergize with TC-210 to increase the potency and durability of response in patients with MSLN+ tumors.Ethics ApprovalAll animal studies were approved by the respective Institutional Animal Care and Use Committees.


Blood ◽  
2002 ◽  
Vol 99 (6) ◽  
pp. 2084-2093 ◽  
Author(s):  
Alexander D. McLellan ◽  
Michaela Kapp ◽  
Andreas Eggert ◽  
Christian Linden ◽  
Ursula Bommhardt ◽  
...  

Abstract Mouse spleen contains CD4+, CD8α+, and CD4−/CD8α− dendritic cells (DCs) in a 2:1:1 ratio. An analysis of 70 surface and cytoplasmic antigens revealed several differences in antigen expression between the 3 subsets. Notably, the Birbeck granule–associated Langerin antigen, as well as CD103 (the mouse homologue of the rat DC marker OX62), were specifically expressed by the CD8α+ DC subset. All DC types were apparent in the T-cell areas as well as in the splenic marginal zones and showed similar migratory capacity in collagen lattices. The 3 DC subtypes stimulated allogeneic CD4+ T cells comparably. However, CD8α+ DCs were very weak stimulators of resting or activated allogeneic CD8+ T cells, even at high stimulator-to-responder ratios, although this defect could be overcome under optimal DC/T cell ratios and peptide concentrations using CD8+ F5 T-cell receptor (TCR)–transgenic T cells. CD8α− or CD8α+DCs presented alloantigens with the same efficiency for lysis by cytotoxic T lymphocytes (CTLs), and their turnover rate of class I–peptide complexes was similar, thus neither an inability to present, nor rapid loss of antigenic complexes from CD8α DCs was responsible for the low allostimulatory capacity of CD8α+ DCs in vitro. Surprisingly, both CD8α+ DCs and CD4−/CD8− DCs efficiently primed minor histocompatibility (H-Y male antigen) cytotoxicity following intravenous injection, whereas CD4+ DCs were weak inducers of CTLs. Thus, the inability of CD8α+ DCs to stimulate CD8+ T cells is limited to certain in vitro assays that must lack certain enhancing signals present during in vivo interaction between CD8α+ DCs and CD8+ T cells.


Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 631
Author(s):  
Jie Wang ◽  
Katarzyna Urbanska ◽  
Prannda Sharma ◽  
Reza Nejati ◽  
Lauren Shaw ◽  
...  

Peripheral T cell lymphomas (PTCLs) are generally chemotherapy resistant and have a poor prognosis. The lack of targeted immunotherapeutic approaches for T cell malignancies results in part from potential risks associated with targeting broadly expressed T cell markers, namely T cell depletion and clinically significant immune compromise. The knowledge that the T cell receptor (TCR) β chain in human α/β TCRs are grouped into Vβ families that can each be targeted by a monoclonal antibody can therefore be exploited for therapeutic purposes. Here, we develop a flexible approach for targeting TCR Vβ families by engineering T cells to express a chimeric CD64 protein that acts as a high affinity immune receptor (IR). We found that CD64 IR-modified T cells can be redirected with precision to T cell targets expressing selected Vβ families by combining CD64 IR-modified T cells with a monoclonal antibody directed toward a specific TCR Vβ family in vitro and in vivo. These findings provide proof of concept that TCR Vβ-family-specific T cell lysis can be achieved using this novel combination cell–antibody platform and illuminates a path toward high precision targeting of T cell malignancies without substantial immune compromise.


Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 2965-2972 ◽  
Author(s):  
Y Kusunoki ◽  
Y Hirai ◽  
S Kyoizumi ◽  
M Akiyama

Abstract Rare T lymphocytes bearing CD3 surface antigen and T-cell receptor (TCR) alpha and beta chains, but lacking both CD4 and CD8 antigens, viz, TCR alpha beta+CD4–8- cells, appear at a frequency of 0.1% to 2% in peripheral blood TCR alpha beta+ cells of normal donors. Here we report two unusual cases, found among 100 healthy individuals studied, who showed an abnormally elevated frequency of these T cells, ie, 5% to 10% and 14% to 19%. Southern blot analyses of the TCR alpha beta+CD4–8- clones all showed the identical rearrangement patterns for each individual, demonstrating that these are derivatives of a single T cell. The same rearrangement patterns were also observed for the freshly isolated lymphocytes of TCR alpha beta+CD4-CD8- fraction, which excludes the possible bias in the processes of in vitro cloning. These TCR alpha beta+CD4–8- T cells were found to express other mature T-cell markers such as CD2, CD3, and CD5 antigens, as well as natural killer (NK) cell markers (CD11b, CD16, CD56, and CD57 antigens) for both individuals. Further, although lectin-dependent or redirected antibody- dependent cell-mediated cytotoxicities were observed for both freshly sorted lymphocytes of TCR alpha beta+CD4–8- fraction and in vitro established clones, NK-like activity was not detected.


1996 ◽  
Vol 183 (6) ◽  
pp. 2481-2488 ◽  
Author(s):  
H W Mittrücker ◽  
A Shahinian ◽  
D Bouchard ◽  
T M Kündig ◽  
T W Mak

We used CD28-deficient mice to analyze the importance of CD28 costimulation for the response against Staphylococcal enterotoxin B (SEB) in vivo. CD28 was necessary for the strong expansion of V beta 8+ T cells, but not for deletion. The lack of expansion was not due to a failure of SEB to activate V beta 8+ T cells, as V beta 8+ T cells from both CD28-/- and CD28+/+ mice showed similar phenotypic changes within the first 24 h after SEB injection and cell cycle analysis showed that an equal percentage of V beta 8+ T cells started to proliferate. However, the phenotype and the state of proliferation of V beta 8+ T cells was different at later time points. Furthermore, in CD28-/- mice injection with SEB led to rapid induction of unresponsiveness in SEB responsive T cells, indicated by a drastic reduction of proliferation after secondary SEB stimulation in vitro. Unresponsiveness could also be demonstrated in vivo, as CD28-/- mice produced only marginal amounts of TNF alpha after rechallenge with SEB. In addition CD28-/- mice were protected against a lethal toxic shock induced by a second injection with SEB. Our results indicate that CD28 costimulation is crucial for the T cell-mediated toxicity of SEB and demonstrate that T cell stimulation in the absence of CD28 costimulation induces unresponsiveness in vivo.


2002 ◽  
Vol 22 (15) ◽  
pp. 5419-5433 ◽  
Author(s):  
Susanne M. A. Lens ◽  
Takao Kataoka ◽  
Karen A. Fortner ◽  
Antoine Tinel ◽  
Isabel Ferrero ◽  
...  

ABSTRACT The caspase 8 inhibitor c-FLIPL can act in vitro as a molecular switch between cell death and growth signals transmitted by the death receptor Fas (CD95). To elucidate its function in vivo, transgenic mice were generated that overexpress c-FLIPL in the T-cell compartment (c-FLIPL Tg mice). As anticipated, FasL-induced apoptosis was inhibited in T cells from the c-FLIPL Tg mice. In contrast, activation-induced cell death of T cells in c-FLIPL Tg mice was unaffected, suggesting that this deletion process can proceed in the absence of active caspase 8. Accordingly, c-FLIPL Tg mice differed from Fas-deficient mice by showing no accumulation of B220+ CD4− CD8− T cells. However, stimulation of T lymphocytes with suboptimal doses of anti-CD3 or antigen revealed increased proliferative responses in T cells from c-FLIPL Tg mice. Thus, a major role of c-FLIPL in vivo is the modulation of T-cell proliferation by decreasing the T-cell receptor signaling threshold.


2004 ◽  
Vol 72 (12) ◽  
pp. 7240-7246 ◽  
Author(s):  
Marion Pepper ◽  
Florence Dzierszinski ◽  
Amy Crawford ◽  
Christopher A. Hunter ◽  
David Roos

ABSTRACT The study of the immune response to Toxoplasma gondii has provided numerous insights into the role of T cells in resistance to intracellular infections. However, the complexity of this eukaryote pathogen has made it difficult to characterize immunodominant epitopes that would allow the identification of T cells with a known specificity for parasite antigens. As a consequence, analysis of T-cell responses to T. gondii has been based on characterization of the percentage of T cells that express an activated phenotype during infection and on the ability of these cells to produce cytokines in response to complex mixtures of parasite antigens. In order to study specific CD4+ T cells responses to T. gondii, recombinant parasites that express a truncated ovalbumin (OVA) protein, in either a cytosolic or a secreted form, were engineered. In vitro and in vivo studies reveal that transgenic parasites expressing secreted OVA are able to stimulate T-cell receptor-transgenic OVA-specific CD4+ T cells to proliferate, express an activated phenotype, and produce gamma interferon (IFN-γ). Furthermore, the adoptive transfer of OVA-specific T cells into IFN-γ−/− mice provided enhanced protection against infection with the OVA-transgenic (but not parental) parasites. Together, these studies establish the utility of this transgenic system to study CD4+-T-cell responses during toxoplasmosis.


Blood ◽  
2011 ◽  
Vol 117 (11) ◽  
pp. 3096-3103 ◽  
Author(s):  
Kenrick Semple ◽  
Antony Nguyen ◽  
Yu Yu ◽  
Honglin Wang ◽  
Claudio Anasetti ◽  
...  

Abstract CD28 costimulation is required for the generation of naturally derived regulatory T cells (nTregs) in the thymus through lymphocyte-specific protein tyrosine kinase (Lck) signaling. However, it is not clear how CD28 costimulation regulates the generation of induced Tregs (iTregs) from naive CD4 T-cell precursors in the periphery. To address this question, we induced iTregs (CD25+Foxp3+) from naive CD4 T cells (CD25−Foxp3−) by T-cell receptor stimulation with additional transforming growth factorβ (TGFβ) in vitro, and found that the generation of iTregs was inversely related to the level of CD28 costimulation independently of IL-2. Using a series of transgenic mice on a CD28-deficient background that bears wild-type or mutated CD28 in its cytosolic tail that is incapable of binding to Lck, phosphoinositide 3-kinase (PI3K), or IL-2–inducible T-cell kinase (Itk), we found that CD28-mediated Lck signaling plays an essential role in the suppression of iTreg generation under strong CD28 costimulation. Furthermore, we demonstrate that T cells with the CD28 receptor incapable of activating Lck were prone to iTreg induction in vivo, which contributed to their reduced ability to cause graft-versus-host disease. These findings reveal a novel mechanistic insight into how CD28 costimulation negatively regulates the generation of iTregs, and provide a rationale for promoting T-cell immunity or tolerance by regulating Tregs through targeting CD28 signaling.


Blood ◽  
2011 ◽  
Vol 118 (13) ◽  
pp. 3528-3537 ◽  
Author(s):  
Maryam Ahmadi ◽  
Judith W. King ◽  
Shao-An Xue ◽  
Cécile Voisine ◽  
Angelika Holler ◽  
...  

Abstract The function of T-cell receptor (TCR) gene modified T cells is dependent on efficient surface expression of the introduced TCR α/β heterodimer. We tested whether endogenous CD3 chains are rate-limiting for TCR expression and antigen-specific T-cell function. We show that co-transfer of CD3 and TCR genes into primary murine T cells enhanced TCR expression and antigen-specific T-cell function in vitro. Peptide titration experiments showed that T cells expressing introduced CD3 and TCR genes recognized lower concentration of antigen than T cells expressing TCR only. In vivo imaging revealed that TCR+CD3 gene modified T cells infiltrated tumors faster and in larger numbers, which resulted in more rapid tumor elimination compared with T cells modified by TCR only. After tumor clearance, TCR+CD3 engineered T cells persisted in larger numbers than TCR-only T cells and mounted a more effective memory response when rechallenged with antigen. The data demonstrate that provision of additional CD3 molecules is an effective strategy to enhance the avidity, anti-tumor activity and functional memory formation of TCR gene modified T cells in vivo.


2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S141-S141
Author(s):  
B Liu ◽  
M Spalinger ◽  
L G Perez ◽  
A Machicote ◽  
N Gagliani ◽  
...  

Abstract Background Inflammatory Bowel Disease (IBD) is characterized by an overwhelming gut inflammation, where CD4+ effector T cells are main mediators of the inflammatory response. Tofacitinib, a small molecular drug recently used in IBD patients, blocks the JAK/STAT signaling pathway necessary for CD4+ effector T-cell activation. However, clinical data show that a percentage of patients do not respond to the treatment. Our main goal is to identify biomarkers predicting the response of patients to tofacitinib. Methods Tofacitinib efficacy was studied in vivo in wild type (WT) and T-cell-specific PTPN2 deficient mice (CD4-Cre;Ptpn2 floxed) in which the JAK/STAT signaling pathway is over activated. WT and PTPN2 deficient mice were gavaged with tofacitinib (50mg/kg, twice daily) or vehicle. Acute DSS-colitis was induced. Colitis development was evaluated by weight loss, colonoscopy and histology. CD4+ T cells were isolated from the colon and analyzed by flow cytometry. To study the effect of tofacitinib on T-cell differentiation, we isolated naïve T cells from mouse spleen and polarized them in vitro to different T-cell subsets with or without tofacitinib. CD4+ T cells differentiation and cytokine production were analyzed by flow cytometry. To evaluate the influence of tofacitinib on human CD4+ T cells, human peripheral blood mononuclear cells (PBMCs) from healthy donors and IBD patients were stimulated in presence of tofacitinib, and analyzed by flow cytometry. Results While no protective effect was found after tofacitinib treatment in WT mice, PTPN2 deficient mice were protected from colitis based on less weight loss, lower endoscopic and histological scores. The expression of pro-inflammatory cytokines such as IL-17 and IFN-γ by colonic CD4+ T cells was also decreased by tofacitinib. Consistent with the in vivo observations, in vitro experiments revealed a strong impact of tofacitinib on CD4+ T-cells cytokine production. In PBMCs from IBD patients, IFN-γ and TNF-α expression was strongly impacted. In contrast, in healthy donors, IL-10 was the most impacted cytokine. Finally, tofacitinib decreased the in vitro differentiation of Th1, Th2, Th17, Th22, Treg and Tr1. Conclusion In the T-cell-specific PTPN2 deficient mice, tofacitinib exerts a protective effect after DSS-induced colitis. In line with the in vivo findings, in vitro experiments show that tofacitinib has a strong impact on pro-inflammatory cytokine production, especially in the IBD patients. Taken together, these data suggest that tofacitinib might be suitable primarily for IBD patients where the JAK/STAT signaling pathway is over activated.


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