Human TCR-MHC coevolution after divergence from mice includes increased nontemplate-encoded CDR3 diversity

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.

Download Full-text

Small amounts of superantigen, when presented on dendritic cells, are sufficient to initiate T cell responses.

Journal of Experimental Medicine ◽

10.1084/jem.178.2.633 ◽

1993 ◽

Vol 178 (2) ◽

pp. 633-642 ◽

Cited By ~ 91

Author(s):

N Bhardwaj ◽

J W Young ◽

A J Nisanian ◽

J Baggers ◽

R M Steinman

Keyword(s):

T Cells ◽

Dendritic Cells ◽

T Cell ◽

Dendritic Cell ◽

Mhc Class Ii ◽

Cell Receptor ◽

Class Ii ◽

Cell Mediated Immunity ◽

Quiescent T Cells ◽

Antigen Presenting

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.

Download Full-text

Naïve Regulatory T Cell Subset Is Altered in X-Linked Agammaglobulinemia

Frontiers in Immunology ◽

10.3389/fimmu.2021.697307 ◽

2021 ◽

Vol 12 ◽

Author(s):

Pavel V. Shelyakin ◽

Ksenia R. Lupyr ◽

Evgeny S. Egorov ◽

Ilya A. Kofiadi ◽

Dmitriy B. Staroverov ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Cell Subset ◽

Cell Receptor ◽

T Cell Subsets ◽

Cell Compartments ◽

Expression Of Genes ◽

Tcr Repertoire ◽

Antigen Presenting

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.

Download Full-text

CD36 family members are TCR-independent ligands for CD1 antigen–presenting molecules

Science Immunology ◽

10.1126/sciimmunol.abg4176 ◽

2021 ◽

Vol 6 (60) ◽

pp. eabg4176

Author(s):

Nicholas A. Gherardin ◽

Samuel J. Redmond ◽

Hamish E. G. McWilliam ◽

Catarina F. Almeida ◽

Katherine H. A. Gourley ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Blood Cells ◽

Ex Vivo ◽

Cell Receptor ◽

Tetramer Staining ◽

Cell Pool ◽

Human T Cell ◽

Tcr Repertoire ◽

Antigen Presenting

CD1c presents lipid-based antigens to CD1c-restricted T cells, which are thought to be a major component of the human T cell pool. However, the study of CD1c-restricted T cells is hampered by the presence of an abundantly expressed, non–T cell receptor (TCR) ligand for CD1c on blood cells, confounding analysis of TCR-mediated CD1c tetramer staining. Here, we identified the CD36 family (CD36, SR-B1, and LIMP-2) as ligands for CD1c, CD1b, and CD1d proteins and showed that CD36 is the receptor responsible for non–TCR-mediated CD1c tetramer staining of blood cells. Moreover, CD36 blockade clarified tetramer-based identification of CD1c-restricted T cells and improved identification of CD1b- and CD1d-restricted T cells. We used this technique to characterize CD1c-restricted T cells ex vivo and showed diverse phenotypic features, TCR repertoire, and antigen-specific subsets. Accordingly, this work will enable further studies into the biology of CD1 and human CD1-restricted T cells.

Download Full-text

CD36 family members are TCR-independent ligands for CD1 antigen-presenting molecules

10.1101/2021.03.10.434884 ◽

2021 ◽

Author(s):

Nicholas A. Gherardin ◽

Samuel J. Redmond ◽

Hamish E.G. McWilliam ◽

Catarina F. Almeida ◽

Katherine H.A. Gourley ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Blood Cells ◽

Ex Vivo ◽

Family Members ◽

Cell Receptor ◽

Tetramer Staining ◽

Human T Cell ◽

Tcr Repertoire ◽

Antigen Presenting

AbstractCD1c presents lipid-based antigens to CD1c-restricted T cells which are thought to be a major component of the human T cell pool. The study of CD1c-restricted T cells, however, is hampered by the presence of an abundantly expressed CD1c-binding partner on blood cells distinct to the T cell receptor (TCR), confounding analysis of TCR-mediated CD1c tetramer staining. Here, we identify the CD36 family (CD36, CD36-L1 and CD36-L2) as novel ligands for CD1c, CD1b and CD1d proteins, and show that CD36 is the receptor responsible for non-TCR-mediated CD1c tetramer staining of blood cells. Moreover, CD36-blockade enables tetramer-based identification of CD1c-restricted T cells and clarifies identification of CD1b- and CD1d-restricted T cells. We use this technique to characterise CD1c-restricted T cells ex vivo and show diverse phenotypic features, TCR repertoire and antigen-specific subsets. Accordingly, this work will enable further studies into the biology of CD1 and human CD1-restricted T cells.One Sentence SummaryCD1 molecules bind CD36 family members and blockade of this interaction facilitates the study of CD1-restricted T cells.

Download Full-text

T-Cell Receptor Vβ Repertoire CDR3 Length Diversity Differs within CD45RA and CD45RO T-Cell Subsets in Healthy and Human Immunodeficiency Virus-Infected Children

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.7.6.953-959.2000 ◽

2000 ◽

Vol 7 (6) ◽

pp. 953-959 ◽

Cited By ~ 21

Author(s):

Zhong Chen Kou ◽

Joshua S. Puhr ◽

Mabel Rojas ◽

Wayne T. McCormack ◽

Maureen M. Goodenow ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Mononuclear Cells ◽

Cell Receptor ◽

T Cell Subsets ◽

Cdr3 Length ◽

Immunodeficiency Virus ◽

Tcr Repertoire ◽

Cell Subpopulations ◽

T Cell Subpopulations

ABSTRACT The T-cell receptor (TCR) CDR3 length heterogeneity is formed during recombination of individual Vβ gene families. We hypothesized that CDR3 length diversity could be used to assess the fundamental differences within the TCR repertoire of CD45RA and CD45RO T-cell subpopulations. By using PCR-based spectratyping, nested primers for all 24 human Vβ families were developed to amplify CDR3 lengths in immunomagnetically selected CD45RA and CD45RO subsets within both CD4+ and CD8+ T-cell populations. Umbilical cord blood mononuclear cells or peripheral blood mononuclear cells obtained from healthy newborns, infants, and children, as well as human immunodeficiency virus (HIV)-infected children, were analyzed. All T-cell subsets from newborn and healthy children demonstrated a Gaussian distribution of CDR3 lengths in separated T-cell subsets. In contrast, HIV-infected children had a high proportion of predominant CDR3 lengths within both CD45RA and CD45RO T-cell subpopulations, most commonly in CD8+ CD45RO T cells. Sharp differences in clonal dominance and size distributions were observed when cells were separated into CD45RA or CD45RO subpopulations. These differences were not apparent in unfractionated CD4+ or CD8+ T cells from HIV-infected subjects. Sequence analysis of predominant CDR3 lengths revealed oligoclonal expansion within individual Vβ families. Analysis of the CDR3 length diversity within CD45RA and CD45RO T cells provides a more accurate measure of disturbances in the TCR repertoire than analysis of unfractionated CD4 and CD8 T cells.

Download Full-text

Conserved T Cell Receptor Repertoire in Primary and Memory CD8 T Cell Responses to an Acute Viral Infection

Journal of Experimental Medicine ◽

10.1084/jem.188.1.71 ◽

1998 ◽

Vol 188 (1) ◽

pp. 71-82 ◽

Cited By ~ 173

Author(s):

David J.D. Sourdive ◽

Kaja Murali-Krishna ◽

John D. Altman ◽

Allan J. Zajac ◽

Jason K. Whitmire ◽

...

Keyword(s):

Amino Acids ◽

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cd8 T Cell ◽

Cell Receptor ◽

Memory Pool ◽

Cdr3 Length ◽

Acute Viral Infection ◽

Tcr Repertoire

Viral infections often induce potent CD8 T cell responses that play a key role in antiviral immunity. After viral clearance, the vast majority of the expanded CD8 T cells undergo apoptosis, leaving behind a stable number of memory cells. The relationship between the CD8 T cells that clear the acute viral infection and the long-lived CD8 memory pool remaining in the individual is not fully understood. To address this issue, we examined the T cell receptor (TCR) repertoire of virus-specific CD8 T cells in the mouse model of infection with lymphocytic choriomeningitis virus (LCMV) using three approaches: (a) in vivo quantitative TCR β chain V segment and complementarity determining region 3 (CDR3) length repertoire analysis by spectratyping (immunoscope); (b) identification of LCMV-specific CD8 T cells with MHC class I tetramers containing viral peptide and costaining with TCR Vβ–specific antibodies; and (c) functional TCR fingerprinting based on recognition of variant peptides. We compared the repertoire of CD8 T cells responding to acute primary and secondary LCMV infections, together with that of virus-specific memory T cells in immune mice. Our analysis showed that CD8 T cells from several Vβ families participated in the anti-LCMV response directed to the dominant cytotoxic T lymphocyte (CTL) epitope (NP118–126). However, the bulk (∼70%) of this CTL response was due to three privileged T cell populations systematically expanding during LCMV infection. Approximately 30% of the response consisted of Vβ10+ CD8 T cells with a β chain CDR3 length of nine amino acids, and 40% consisted of Vβ8.1+ (β CDR3 = eight amino acids) and Vβ8.2+ cells (β CDR3 = six amino acids). Finally, we showed that the TCR repertoire of the primary antiviral CD8 T cell response was similar both structurally and functionally to that of the memory pool and the secondary CD8 T cell effectors. These results suggest a stochastic selection of memory cells from the pool of CD8 T cells activated during primary infection.

Download Full-text

CD1: From Molecules to Diseases

F1000Research ◽

10.12688/f1000research.12178.1 ◽

2017 ◽

Vol 6 ◽

pp. 1909 ◽

Cited By ~ 2

Author(s):

D. Branch Moody ◽

Sara Suliman

Keyword(s):

T Cells ◽

T Cell ◽

Ex Vivo ◽

Cell Receptor ◽

High Genetic Diversity ◽

Disease States ◽

New Research ◽

Antigen Presenting ◽

Cluster Of Differentiation

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.

Download Full-text

Fyn-Binding Protein (Fyb)/Slp-76–Associated Protein (Slap), Ena/Vasodilator-Stimulated Phosphoprotein (Vasp) Proteins and the Arp2/3 Complex Link T Cell Receptor (Tcr) Signaling to the Actin Cytoskeleton

The Journal of Cell Biology ◽

10.1083/jcb.149.1.181 ◽

2000 ◽

Vol 149 (1) ◽

pp. 181-194 ◽

Cited By ~ 210

Author(s):

Matthias Krause ◽

Antonio S. Sechi ◽

Marlies Konradt ◽

David Monner ◽

Frank B. Gertler ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Actin Cytoskeleton ◽

T Cell Receptor ◽

Cell Receptor ◽

T Cell Signaling ◽

Tcr Signaling ◽

Activated T Cells ◽

Antigen Presenting ◽

Syndrome Protein

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.

Download Full-text

Arming T Cells with a gp100-Specific TCR and a CSPG4-Specific CAR Using Combined DNA- and RNA-Based Receptor Transfer

Cancers ◽

10.3390/cancers11050696 ◽

2019 ◽

Vol 11 (5) ◽

pp. 696 ◽

Cited By ~ 5

Author(s):

Bianca Simon ◽

Dennis C. Harrer ◽

Beatrice Schuler-Thurner ◽

Gerold Schuler ◽

Ugur Uslu

Keyword(s):

T Cells ◽

T Cell ◽

Tumor Cells ◽

Immune Escape ◽

Cell Receptor ◽

Adoptive T Cell Therapy ◽

T Cell Therapy ◽

Dna And Rna ◽

Antigen Loss ◽

Antigen Presenting

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.

Download Full-text