scholarly journals CD1d-restricted Recognition of Synthetic Glycolipid Antigens by Human Natural Killer T Cells

1998 ◽  
Vol 188 (8) ◽  
pp. 1529-1534 ◽  
Author(s):  
Franca M. Spada ◽  
Yasuhiko Koezuka ◽  
Steven A. Porcelli

A conserved subset of mature circulating T cells in humans expresses an invariant Vα24-JαQ T cell receptor (TCR)-α chain rearrangement and several natural killer (NK) locus–encoded C-type lectins. These human T cells appear to be precise homologues of the subset of NK1.1+ TCR-α/β+ T cells, often referred to as NK T cells, which was initially identified in mice. Here we show that human NK T cell clones are strongly and specifically activated by the same synthetic glycolipid antigens as have been shown recently to stimulate murine NK T cells. Responses of human NK T cells to these synthetic glycolipids, consisting of certain α-anomeric sugars conjugated to an acylated phytosphingosine base, required presentation by antigen-presenting cells expressing the major histocompatibility complex class I–like CD1d protein. Presentation of synthetic glycolipid antigens to human NK T cells required internalization of the glycolipids by the antigen-presenting cell and normal endosomal targeting of CD1d. Recognition of these compounds by human NK T cells triggered proliferation, cytokine release, and cytotoxic activity. These results demonstrate a striking parallel in the specificity of NK T cells in humans and mice, thus providing further insight into the potential mechanisms of immune recognition by NK T cells and the immunological function of this unique T cell subset.

1998 ◽  
Vol 188 (8) ◽  
pp. 1521-1528 ◽  
Author(s):  
Laurent Brossay ◽  
Mariacristina Chioda ◽  
Nicolas Burdin ◽  
Yasuhiko Koezuka ◽  
Giulia Casorati ◽  
...  

Natural killer (NK) T cells are a lymphocyte subset with a distinct surface phenotype, an invariant T cell receptor (TCR), and reactivity to CD1. Here we show that mouse NK T cells can recognize human CD1d as well as mouse CD1, and human NK T cells also recognize both CD1 homologues. The unprecedented degree of conservation of this T cell recognition system suggests that it is fundamentally important. Mouse or human CD1 molecules can present the glycolipid α-galactosylceramide (α-GalCer) to NK T cells from either species. Human T cells, preselected for invariant Vα24 TCR expression, uniformly recognize α-GalCer presented by either human CD1d or mouse CD1. In addition, culture of human peripheral blood cells with α-GalCer led to the dramatic expansion of NK T cells with an invariant (Vα24+) TCR and the release of large amounts of cytokines. Because invariant Vα14+ and Vα24+ NK T cells have been implicated both in the control of autoimmune disease and the response to tumors, our data suggest that α-GalCer could be a useful agent for modulating human immune responses by activation of the highly conserved NK T cell subset.


2021 ◽  
Vol 12 ◽  
Author(s):  
Pavel V. Shelyakin ◽  
Ksenia R. Lupyr ◽  
Evgeny S. Egorov ◽  
Ilya A. Kofiadi ◽  
Dmitriy B. Staroverov ◽  
...  

The interplay between T- and B-cell compartments during naïve, effector and memory T cell maturation is critical for a balanced immune response. Primary B-cell immunodeficiency arising from X-linked agammaglobulinemia (XLA) offers a model to explore B cell impact on T cell subsets, starting from the thymic selection. Here we investigated characteristics of naïve and effector T cell subsets in XLA patients, revealing prominent alterations in the corresponding T-cell receptor (TCR) repertoires. We observed immunosenescence in terms of decreased diversity of naïve CD4+ and CD8+ TCR repertoires in XLA donors. The most substantial alterations were found within naïve CD4+ subsets, and we have investigated these in greater detail. In particular, increased clonality and convergence, along with shorter CDR3 regions, suggested narrower focused antigen-specific maturation of thymus-derived naïve Treg (CD4+CD45RA+CD27+CD25+) in the absence of B cells - normally presenting diverse self and commensal antigens. The naïve Treg proportion among naïve CD4 T cells was decreased in XLA patients, supporting the concept of impaired thymic naïve Treg selection. Furthermore, the naïve Treg subset showed prominent differences at the transcriptome level, including increased expression of genes specific for antigen-presenting and myeloid cells. Altogether, our findings suggest active B cell involvement in CD4 T cell subsets maturation, including B cell-dependent expansion of the naïve Treg TCR repertoire that enables better control of self-reactive T cells.


2002 ◽  
Vol 196 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Nadine Y. Crowe ◽  
Mark J. Smyth ◽  
Dale I. Godfrey

Natural killer (NK) T cells initiate potent antitumor responses when stimulated by exogenous factors such as interleukin (IL)-12 or α-galactosylceramide (α-GalCer), however, it is not clear whether this reflects a physiological role for these cells in tumor immunity. Through adoptive transfer of NK T cells from wild-type to NK T cell–deficient (T cell receptor [TCR] Jα281−/−) mice, we demonstrate a critical role for NK T cells in immunosurveillance of methylcholanthrene (MCA)-induced fibrosarcomas, in the absence of exogenous stimulatory factors. Using the same approach with gene-targeted and/or antibody-depleted donor or recipient mice, we have shown that this effect depends on CD1d recognition and requires the additional involvement of both NK and CD8+ T cells. Interferon-γ production by both NK T cells and downstream, non-NK T cells, is essential for protection, and perforin production by effector cells, but not NK T cells, is also critical. The protective mechanisms in this more physiologically relevant system are distinct from those associated with α-GalCer–induced, NK T cell–mediated, tumor rejection. This study demonstrates that, in addition to their importance in tumor immunotherapy induced by IL-12 or α-GalCer, NK T cells can play a critical role in tumor immunosurveillance, at least against MCA-induced sarcomas, in the absence of exogenous stimulation.


2017 ◽  
Author(s):  
A. Wahl ◽  
C. Dinet ◽  
P. Dillard ◽  
P-H. Puech ◽  
L. Limozin ◽  
...  

Force sensitivity of the T cell receptor (TCR) is now believed to be essential for immune recognition, but cellular mechanosensitivity of T cells is still poorly understood. Here we show that T cells adhering via the TCR-complex respond to environmental stiffness in an unusual biphasic fashion. As the stiffness increases, adhesion and spreading first increase, then decrease, attaining their maximal values on an optimally stiff surface, with stiffness comparable to certain antigen presenting cells. Remarkably, in presence of additional ligands for the integrin LFA-1, spreading increases monotonously with stiffness up to a saturation value. Using a mesoscopic semi-analytical model linking spreading to molecular characteristics of bonds, we identify force sensitivity of the off-rate and the effective bond stiffness as the crucial parameters that determine monotonic or biphasic mechanosensitive behavior.


2017 ◽  
Vol 214 (11) ◽  
pp. 3417-3433 ◽  
Author(s):  
Xiaojing Chen ◽  
Lucia Poncette ◽  
Thomas Blankenstein

For thymic selection and responses to pathogens, T cells interact through their αβ T cell receptor (TCR) with peptide–major histocompatibility complex (MHC) molecules on antigen-presenting cells. How the diverse TCRs interact with a multitude of MHC molecules is unresolved. It is also unclear how humans generate larger TCR repertoires than mice do. We compared the TCR repertoire of CD4 T cells selected from a single mouse or human MHC class II (MHC II) in mice containing the human TCR gene loci. Human MHC II yielded greater thymic output and a more diverse TCR repertoire. The complementarity determining region 3 (CDR3) length adjusted for different inherent V-segment affinities to MHC II. Humans evolved with greater nontemplate-encoded CDR3 diversity than did mice. Our data, which demonstrate human TCR–MHC coevolution after divergence from rodents, explain the greater T cell diversity in humans and suggest a mechanism for ensuring that any V–J gene combination can be selected by a single MHC II.


1993 ◽  
Vol 178 (2) ◽  
pp. 633-642 ◽  
Author(s):  
N Bhardwaj ◽  
J W Young ◽  
A J Nisanian ◽  
J Baggers ◽  
R M Steinman

Dendritic cells are potent antigen-presenting cells for several primary immune responses and therefore provide an opportunity for evaluating the amounts of cell-associated antigens that are required for inducing T cell-mediated immunity. Because dendritic cells express very high levels of major histocompatibility complex (MHC) class II products, it has been assumed that high levels of ligands bound to MHC products ("signal one") are needed to stimulate quiescent T cells. Here we describe quantitative aspects underlying the stimulation of human blood T cells by a bacterial superantigen, staphylococcal enterotoxin A (SEA). The advantages of superantigens for quantitative studies of signal one are that these ligands: (a) engage MHC class II and the T cell receptor but do not require processing; (b) are efficiently presented to large numbers of quiescent T cells; and (c) can be pulsed onto dendritic cells before their application to T cells. Thus one can relate amounts of dendritic cell-associated SEA to subsequent lymphocyte stimulation. Using radioiodinated SEA, we noted that dendritic cells can bind 30-200 times more superantigen than B cells and monocytes. Nevertheless, this high SEA binding does not underlie the strong potency of dendritic cells to present antigen to T cells. Dendritic cells can sensitize quiescent T cells, isolated using monoclonals to appropriate CD45R epitopes, after a pulse of SEA that occupies a maximum of 0.1% of surface MHC class II molecules. This corresponds to an average of 2,000 molecules per dendritic cell. At these low doses of bound SEA, monoclonal antibodies to CD3, CD4, and CD28 almost completely block T cell proliferation. In addition to suggesting new roles for MHC class II on dendritic cells, especially the capture and retention of ligands at low external concentrations, the data reveal that primary T cells can generate a response to exceptionally low levels of signal one as long as these are delivered on dendritic cells.


F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1909 ◽  
Author(s):  
D. Branch Moody ◽  
Sara Suliman

The human cluster of differentiation (CD)1 system for antigen display is comprised of four types of antigen-presenting molecules, each with a distinct functional niche: CD1a, CD1b, CD1c, and CD1d. Whereas CD1 proteins were thought solely to influence T-cell responses through display of amphipathic lipids, recent studies emphasize the role of direct contacts between the T-cell receptor and CD1 itself. Moving from molecules to diseases, new research approaches emphasize human CD1-transgenic mouse models and the study of human polyclonal T cells in vivo or ex vivo in disease states. Whereas the high genetic diversity of major histocompatibility complex (MHC)-encoded antigen-presenting molecules provides a major hurdle for designing antigens that activate T cells in all humans, the simple population genetics of the CD1 system offers the prospect of discovering or designing broadly acting immunomodulatory agents.


1991 ◽  
Vol 174 (2) ◽  
pp. 417-424 ◽  
Author(s):  
T Abo ◽  
T Ohteki ◽  
S Seki ◽  
N Koyamada ◽  
Y Yoshikai ◽  
...  

We demonstrated in the present study that with bacterial stimulation, an increased number of alpha/beta T cells proliferated in the liver of mice and that even T cells bearing self-reactive T cell receptor (TCR) (or forbidden T cell clones), as estimated by anti-V beta monoclonal antibodies in conjunction with immunofluorescence tests, appeared in the liver and, to some extent, in the periphery. The majority (greater than 80%) of forbidden clones induced had double-negative CD4-8-phenotype. In a syngeneic mixed lymphocyte reaction, these T cells appear to be self-reactive. Such forbidden clones and normal T cells in the liver showed a two-peak pattern of TCR expression, which consisted of alpha/beta TCR dull and bright positive cells, as seen in the thymus. A systematic analysis of TCR staining patterns in the various organs was then carried out. T cells from not only the thymus but also the liver had the two-peak pattern of alpha/beta TCR, whereas all of the other peripheral lymphoid organs had a single-peak pattern of TCR. However, T cells in the liver were not comprised of double-positive CD4+8+ cells, which predominantly reside in the thymus. The present results therefore suggest that T cell proliferation in the liver might reflect a major extrathymic pathway for T cell differentiation and that this hepatic pathway has the ability to produce T cells bearing self-reactive TCR under bacterial stimulation, probably due to the lack of a double-positive stage for negative selection.


2000 ◽  
Vol 149 (1) ◽  
pp. 181-194 ◽  
Author(s):  
Matthias Krause ◽  
Antonio S. Sechi ◽  
Marlies Konradt ◽  
David Monner ◽  
Frank B. Gertler ◽  
...  

T cell receptor (TCR)-driven activation of helper T cells induces a rapid polarization of their cytoskeleton towards bound antigen presenting cells (APCs). We have identified the Fyn- and SLP-76–associated protein Fyb/SLAP as a new ligand for Ena/ vasodilator-stimulated phosphoprotein (VASP) homology 1 (EVH1) domains. Upon TCR engagement, Fyb/SLAP localizes at the interface between T cells and anti-CD3–coated beads, where Evl, a member of the Ena/VASP family, Wiskott-Aldrich syndrome protein (WASP) and the Arp2/3 complex are also found. In addition, Fyb/SLAP is restricted to lamellipodia of spreading platelets. In activated T cells, Fyb/SLAP associates with Ena/VASP family proteins and is present within biochemical complexes containing WASP, Nck, and SLP-76. Inhibition of binding between Fyb/SLAP and Ena/VASP proteins or WASP and the Arp2/3 complex impairs TCR-dependent actin rearrangement, suggesting that these interactions play a key role in linking T cell signaling to remodeling of the actin cytoskeleton.


Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 696 ◽  
Author(s):  
Bianca Simon ◽  
Dennis C. Harrer ◽  
Beatrice Schuler-Thurner ◽  
Gerold Schuler ◽  
Ugur Uslu

Tumor cells can develop immune escape mechanisms to bypass T cell recognition, e.g., antigen loss or downregulation of the antigen presenting machinery, which represents a major challenge in adoptive T cell therapy. To counteract these mechanisms, we transferred not only one, but two receptors into the same T cell to generate T cells expressing two additional receptors (TETARs). We generated these TETARs by lentiviral transduction of a gp100-specific T cell receptor (TCR) and subsequent electroporation of mRNA encoding a second-generation CSPG4-specific chimeric antigen receptor (CAR). Following pilot experiments to optimize the combined DNA- and RNA-based receptor transfer, the functionality of TETARs was compared to T cells either transfected with the TCR only or the CAR only. After transfection, TETARs clearly expressed both introduced receptors on their cell surface. When stimulated with tumor cells expressing either one of the antigens or both, TETARs were able to secrete cytokines and showed cytotoxicity. The confirmation that two antigen-specific receptors can be functionally combined using two different methods to introduce each receptor into the same T cell opens new possibilities and opportunities in cancer immunotherapy. For further evaluation, the use of these TETARs in appropriate animal models will be the next step towards a potential clinical use in cancer patients.


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