scholarly journals CD6 modulates thymocyte selection and peripheral T cell homeostasis

2016 ◽  
Vol 213 (8) ◽  
pp. 1387-1397 ◽  
Author(s):  
Marc Orta-Mascaró ◽  
Marta Consuegra-Fernández ◽  
Esther Carreras ◽  
Romain Roncagalli ◽  
Amado Carreras-Sureda ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immunological Synapse ◽  
Cell Receptor ◽  
Autoimmune Response ◽  
Effector Memory ◽  
Thymocyte Development ◽  
Double Positive

The CD6 glycoprotein is a lymphocyte surface receptor putatively involved in T cell development and activation. CD6 facilitates adhesion between T cells and antigen-presenting cells through its interaction with CD166/ALCAM (activated leukocyte cell adhesion molecule), and physically associates with the T cell receptor (TCR) at the center of the immunological synapse. However, its precise role during thymocyte development and peripheral T cell immune responses remains to be defined. Here, we analyze the in vivo consequences of CD6 deficiency. CD6−/− thymi showed a reduction in both CD4+ and CD8+ single-positive subsets, and double-positive thymocytes exhibited increased Ca2+ mobilization to TCR cross-linking in vitro. Bone marrow chimera experiments revealed a T cell–autonomous selective disadvantage of CD6−/− T cells during development. The analysis of TCR-transgenic mice (OT-I and Marilyn) confirmed that abnormal T cell selection events occur in the absence of CD6. CD6−/− mice displayed increased frequencies of antigen-experienced peripheral T cells generated under certain levels of TCR signal strength or co-stimulation, such as effector/memory (CD4+TEM and CD8+TCM) and regulatory (T reg) T cells. The suppressive activity of CD6−/− T reg cells was diminished, and CD6−/− mice presented an exacerbated autoimmune response to collagen. Collectively, these data indicate that CD6 modulates the threshold for thymocyte selection and the generation and/or function of several peripheral T cell subpopulations, including T reg cells.

scholarly journals TAGLN2 regulates T cell activation by stabilizing the actin cytoskeleton at the immunological synapse

2015 ◽  
Vol 209 (1) ◽  
pp. 143-162 ◽  
Author(s):  
Bo-Ra Na ◽  
Hye-Ran Kim ◽  
Indre Piragyte ◽  
Hyun-Mee Oh ◽  
Min-Sung Kwon ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immunological Synapse ◽  
Cell Receptor ◽  
Actin Dynamics ◽  
Actin Binding

The formation of an immunological synapse (IS) requires tight regulation of actin dynamics by many actin polymerizing/depolymerizing proteins. However, the significance of actin stabilization at the IS remains largely unknown. In this paper, we identify a novel function of TAGLN2—an actin-binding protein predominantly expressed in T cells—in stabilizing cortical F-actin, thereby maintaining F-actin contents at the IS and acquiring LFA-1 (leukocyte function-associated antigen-1) activation after T cell receptor stimulation. TAGLN2 blocks actin depolymerization and competes with cofilin both in vitro and in vivo. Knockout of TAGLN2 (TAGLN2−/−) reduced F-actin content and destabilized F-actin ring formation, resulting in decreased cell adhesion and spreading. TAGLN2−/− T cells displayed weakened cytokine production and cytotoxic effector function. These findings reveal a novel function of TAGLN2 in enhancing T cell responses by controlling actin stability at the IS.

scholarly journals The concurrent maturation of mouse and human thymocytes in human fetal thymus implanted in NIH-beige-nude-xid mice is associated with the reconstitution of the murine immune system.

1993 ◽  
Vol 177 (3) ◽  
pp. 821-832 ◽  
Author(s):  
T R Kollmann ◽  
M M Goldstein ◽  
H Goldstein
Keyword(s):  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Keyhole Limpet Hemocyanin ◽  
Cell Receptor ◽  
Scid Mice ◽  
Double Positive ◽  
Fetal Thymus

To determine whether the human thymus provides an environment for the maturation of murine T cells, human fetal thymus and liver (hu-thy/liv) were implanted into congenitally athymic NIH-beige-nude-xid (BNX) mice or C.B-17 scid/scid (SCID) mice. 3 mo after implantation, in contrast to the hu-thy/liv implant in SCID mice, which was populated only with human CD4/CD8 single- and double-positive thymocytes, the hu-thy/liv implant in BNX mice contained a chimeric population of human and mouse CD4/CD8 single- and double-positive thymocytes. Immunohistochemical staining of the hu-thy/liv implant in BNX mice indicated that the population of double-positive mouse thymocytes was localized to discrete areas of the human fetal thymus. Quantitative improvements in mouse T cell and immunoglobulin (Ig) G parameters were observed after grafting of the human fetal thymus and liver tissue into BNX mice. In addition, in contrast to the nonimplanted BNX mice, the implanted BNX mice were capable of mounting a keyhole limpet hemocyanin-specific IgG response and their peripheral T cells were responsive to stimulation with mitogens and antibodies directed to the T cell receptor. Furthermore, after in vivo priming, T cells present in lymph nodes of the implanted BNX mice were capable of mounting an antigen-induced in vitro T cell-dependent proliferative response. Thus, concurrent with the continued maturation of human T cells, murine T cells differentiated within the human fetal thymus implanted in the BNX mice and mediated the phenotypic and functional reconstitution of the murine immune system. Mice with a reconstituted immune system that contain a human thymic implant that is infectible with human immunodeficiency virus (HIV) should prove useful in the investigation of T cell maturation in the thymus and in the evaluation of potential HIV vaccines.

scholarly journals Interleukin 4 expressed in situ selectively alters thymocyte development.

1991 ◽  
Vol 173 (1) ◽  
pp. 89-100 ◽  
Author(s):  
D B Lewis ◽  
C C Yu ◽  
K A Forbush ◽  
J Carpenter ◽  
T A Sato ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Receptor ◽  
Interleukin 4 ◽  
Thymocyte Development ◽  
Double Positive ◽  
Peripheral T Cells ◽  
Single Positive ◽  
And Control

Using a transgenic mouse model we show that increased intrathymic expression of interleukin 4 (IL-4) significantly perturbs the development of thymocytes. Transgenic double-positive (CD4+CD8+) thymocytes, which are present in dramatically reduced numbers, exhibit increased T cell receptor (TCR) expression and increased mobilization of calcium mediated by these receptors. In contrast, transgenic single-positive (CD4+CD8- and CD4-CD8+) thymocytes and peripheral T cells exhibit decreased TCR-mediated calcium mobilization. The development of CD4-CD8+ thymocytes is significantly perturbed by IL-4 expressed in vivo; only peripheral CD4+ T cells are found in significant numbers in transgenic mice, while CD4-CD8+ thymocytes are present in increased numbers, apparently because of their failure to emigrate to the periphery. In contrast to these selective effects on T cell development, no significant differences in the numbers of B cells or mast cells, or in the plasma levels of IgE and IgG1 are observed between transgenic and control mice. These observations suggest that IL-4 in vivo exerts its major effects locally rather than systemically, even when its expression is constitutively increased.

scholarly journals 173 Expression of a membrane-tethered IL-15/IL-15 receptor fusion protein enhances the persistence of MSLN-targeted TRuC-T cells

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A185-A185
Author(s):  
Michelle Fleury ◽  
Derrick McCarthy ◽  
Holly Horton ◽  
Courtney Anderson ◽  
Amy Watt ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Fusion Protein ◽  
T Cell Receptor ◽  
Cytokine Production ◽  
Cell Receptor ◽  
Great Promise ◽  
And Function

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.

scholarly journals A Novel Role for IL-6 Receptor Classic Signaling: Induction of RORγt+Foxp3+ Tregs with Enhanced Suppressive Capacity

2019 ◽  
Vol 30 (8) ◽  
pp. 1439-1453 ◽  
Author(s):  
Julia Hagenstein ◽  
Simon Melderis ◽  
Anna Nosko ◽  
Matthias T. Warkotsch ◽  
Johannes V. Richter ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Adoptive Transfer ◽  
Th17 Cells ◽  
Inflammatory Diseases ◽  
Double Positive ◽  
T Effector Cells ◽  
Suppressive Capacity

BackgroundNew therapies blocking the IL-6 receptor (IL-6R) have recently become available and are successfully being used to treat inflammatory diseases like arthritis. Whether IL-6 blockers may help patients with kidney inflammation currently remains unknown.MethodsTo learn more about the complex role of CD4+ T cell-intrinsic IL-6R signaling, we induced nephrotoxic nephritis, a mouse model for crescentic GN, in mice lacking T cell–specific IL-6Ra. We used adoptive transfer experiments and studies in reporter mice to analyze immune responses and Treg subpopulations.ResultsLack of IL-6Ra signaling in mouse CD4+ T cells impaired the generation of proinflammatory Th17 cells, but surprisingly did not ameliorate the course of GN. In contrast, renal damage was significantly reduced by restricting IL-6Ra deficiency to T effector cells and excluding Tregs. Detailed studies of Tregs revealed unaltered IL-10 production despite IL-6Ra deficiency. However, in vivo and in vitro, IL-6Ra classic signaling induced RORγt+Foxp3+ double-positive Tregs (biTregs), which carry the trafficking receptor CCR6 and have potent immunoregulatory properties. Indeed, lack of IL-6Ra significantly reduced Treg in vitro suppressive capacity. Finally, adoptive transfer of T cells containing IL-6Ra−/− Tregs resulted in severe aggravation of GN in mice.ConclusionsOur data refine the old paradigm, that IL-6 enhances Th17 responses and suppresses Tregs. We here provide evidence that T cell–intrinsic IL-6Ra classic signaling indeed induces the generation of Th17 cells but at the same time highly immunosuppressive RORγt+ biTregs. These results advocate caution and indicate that IL-6–directed therapies for GN need to be cell-type specific.

Anatomic location and T-cell stimulatory functions of mouse dendritic cell subsets defined by CD4 and CD8 expression

Blood ◽  
2002 ◽  
Vol 99 (6) ◽  
pp. 2084-2093 ◽  
Author(s):  
Alexander D. McLellan ◽  
Michaela Kapp ◽  
Andreas Eggert ◽  
Christian Linden ◽  
Ursula Bommhardt ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Antigen Expression ◽  
Cell Receptor ◽  
In Vitro Assays ◽  
Peptide Complexes ◽  
Marginal Zones

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.

scholarly journals A Novel Approach for the Treatment of T Cell Malignancies: Targeting T Cell Receptor Vβ Families

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 631
Author(s):  
Jie Wang ◽  
Katarzyna Urbanska ◽  
Prannda Sharma ◽  
Reza Nejati ◽  
Lauren Shaw ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
T Cell Lymphomas ◽  
Novel Approach ◽  
T Cell Malignancies

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.

scholarly journals Evidence for in vivo clonal proliferation of unique population of blood CD4-/CD8- T cells bearing T-cell receptor alpha and beta chains in two normal men

Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 2965-2972 ◽  
Author(s):  
Y Kusunoki ◽  
Y Hirai ◽  
S Kyoizumi ◽  
M Akiyama
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Nk Cell ◽  
Cell Receptor ◽  
Cell Markers ◽  
Clonal Proliferation ◽  
Alpha Beta

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.

β-Selection Is Associated With the Onset of CD8β Chain Expression on CD4+CD8+ Pre-T Cells During Human Intrathymic Development

Blood ◽  
1999 ◽  
Vol 94 (10) ◽  
pp. 3491-3498 ◽  
Author(s):  
Yolanda R. Carrasco ◽  
César Trigueros ◽  
Almudena R. Ramiro ◽  
Virginia G. de Yébenes ◽  
Marı́a L. Toribio
Keyword(s):  
T Cells ◽  
T Cell ◽  
Control Point ◽  
Intermediate Stage ◽  
Cell Receptor ◽  
Resting Cells ◽  
Double Positive ◽  
Human T Cell ◽  
A Minor

T-cell precursors that undergo productive rearrangements at the T-cell receptor (TCR) β locus are selected for proliferation and further maturation, before TCR expression, by signaling through a pre–TCR composed of the TCRβ chain paired with a pre–TCR (pT) chain. Such a critical developmental checkpoint, known as β-selection, results in progression from CD4−CD8− double negative (DN) to CD4+CD8+ double positive (DP) TCRβ−thymocytes. In contrast to mice, progression to the DP compartment occurs in humans via a CD4+ CD8−intermediate stage. Here we show that the CD4+CD8− to CD4+ CD8+ transition involves the sequential acquisition of the  and β chains of CD8 at distinct maturation stages. Our results indicate that CD8, but not CD8β, is expressed in vivo in a minor subset of DP TCRβ− thymocytes, referred to as CD4+CD8+ pre-T cells, mostly composed of resting cells lacking cytoplasmic TCRβ chain (TCRβic). In contrast, expression of CD8β heterodimers was selectively found on DP TCRβ− thymocytes that express TCRβicand are enriched for cycling cells. Interestingly, CD4+CD8+ pre-T cells are shown to be functional intermediates between CD4+ CD8−TCRβic− and CD4+CD8β+ TCRβic+thymocytes. More importantly, evidence is provided that onset of CD8β and TCRβic expression are coincident developmental events associated with acquisition of CD3 and pT chain on the cell surface. Therefore, we propose that the CD4+CD8+ to CD4+CD8β+ transition marks the key control point of pre-TCR–mediated β-selection in human T-cell development.

scholarly journals The Caspase 8 Inhibitor c-FLIPL Modulates T-Cell Receptor-Induced Proliferation but Not Activation-Induced Cell Death of Lymphocytes

2002 ◽  
Vol 22 (15) ◽  
pp. 5419-5433 ◽  
Author(s):  
Susanne M. A. Lens ◽  
Takao Kataoka ◽  
Karen A. Fortner ◽  
Antoine Tinel ◽  
Isabel Ferrero ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
T Cell Receptor ◽  
Death Receptor ◽  
Cell Receptor ◽  
Caspase 8 ◽  
Activation Induced Cell Death

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.

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