T-cell receptor

T cell receptorTCRT-cell receptorsT cell receptorsTCRsreceptorT-T-cell antigen receptors T cell receptor/TCR(TCR)
The T-cell receptor (TCR) is a molecule found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules.wikipedia
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T cell

T cellsT-cellT-cells
The T-cell receptor (TCR) is a molecule found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules.
T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor on the cell surface.

Antigen

antigensantigenicantigenic proteins
The T-cell receptor (TCR) is a molecule found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules.
It was expanded later to refer to any molecule or a linear molecular fragment after processing the native antigen that can be recognized by T-cell receptor (TCR).

Major histocompatibility complex

MHCmajor histocompatibility complex (MHC)HLA loci
The T-cell receptor (TCR) is a molecule found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules. Each T cell expresses clonal TCRs which recognize a specific peptide loaded on a MHC molecule (pMHC), either on MHC class II on the surface of antigen presenting cells or MHC class I on any other cell type.
MHC is also the chaperone for intracellular peptides that are complexed with MHCs and presented to T cell receptors (TCRs) as potential foreign antigens.

TRG (gene)

TRGTRG@
In humans, in 95% of T cells the TCR consists of an alpha chain and a beta chain (encoded by TRA and TRB, respectively), whereas in 5% of T cells the TCR consists of gamma and delta chains (encoded by TRG and TRD, respectively).
It contributes the gamma chain to the larger TCR protein (T-cell receptor).

Tak Wah Mak

Tak MakTak W. MakAdvanced Medical Discovery Institute
In 1984, Tak Wah Mak and Mark M. Davis discovered the human and mouse TCR respectively.
He first became widely known for his discovery of the T-cell receptor in 1983 and pioneering work in the genetics of immunology.

Chimeric antigen receptor T cell

chimeric antigen receptorCAR-TCAR T
This allowed scientists from around the world to carry out studies on the TCR, leading to important studies in the fields of CAR-T, Cancer immunotherapy and Checkpoint inhibition.
Chimeric antigen receptor T cells (also known as CAR T cells) are T cells that have been genetically engineered to produce an artificial T-cell receptor for use in immunotherapy.

Gamma delta T cell

γδ T cellsγδ T cellVγ9/Vδ2 T cells
In humans, in 95% of T cells the TCR consists of an alpha chain and a beta chain (encoded by TRA and TRB, respectively), whereas in 5% of T cells the TCR consists of gamma and delta chains (encoded by TRG and TRD, respectively).
Gamma delta T cells (γδ T cells) are T cells that have a distinctive T-cell receptor (TCR) on their surface.

Complementarity-determining region

complementarity determining regioncomplementarity determining regionsCDR3
The variable domain of both the TCR α-chain and β-chain each have three hypervariable or complementarity determining regions (CDRs). Later during development, individual CDR loops of TCR can be re-edited in the periphery outside thymus by reactivation of recombinases using a process termed TCR revision (editing) and change its antigenic specificity.
Complementarity-determining regions (CDRs) are part of the variable chains in immunoglobulins (antibodies) and T cell receptors, generated by B-cells and T-cells respectively, where these molecules bind to their specific antigen.

V(D)J recombination

immunoglobulin genegene rearrangementrearrange TCR genes
It arises mainly from genetic recombination of the DNA encoded segments in individual somatic T cells by somatic V(D)J recombination using RAG1 and RAG2 recombinases.
It involves somatic recombination, and results in the highly diverse repertoire of antibodies/immunoglobulins (Igs) and T cell receptors (TCRs) found on B cells and T cells, respectively.

Immunoglobulin superfamily

Immunoglobulin (Ig) superfamilyimmunoglobulinIg
Each chain is composed of two extracellular domains: Variable (V) region and a Constant (C) region, both of Immunoglobulin superfamily (IgSF) domain forming antiparallel β-sheets.

Superantigen

superantigenssuper antigenssuper-antigens
CDR4 of the β-chain is not thought to participate in antigen recognition, but has been shown to interact with superantigens.
The domains have binding regions for the Major Histocompatibility Complex Class II (MHC Class II) and the T cell receptor (TCR), respectively.

T cell receptor revision

TCR revision
Later during development, individual CDR loops of TCR can be re-edited in the periphery outside thymus by reactivation of recombinases using a process termed TCR revision (editing) and change its antigenic specificity.
T cell receptor revision (alternative term: antigen receptor editing) is a process in the peripheral immune system which is used by mature T cells to alter their original antigenic specificity based on rearranged T cell receptors (TCR).

Cancer immunotherapy

immunotherapyimmunooncologyimmuno-oncology
This allowed scientists from around the world to carry out studies on the TCR, leading to important studies in the fields of CAR-T, Cancer immunotherapy and Checkpoint inhibition.
In normal physiology T-cells are activated by two signals: the T-cell receptor binding to an antigen-MHC complex and T-cell surface receptor CD28 binding to CD80 or CD86 proteins.

RAG2

It arises mainly from genetic recombination of the DNA encoded segments in individual somatic T cells by somatic V(D)J recombination using RAG1 and RAG2 recombinases.
Together with RAG1 protein, RAG2 forms a V(D)J recombinase, a protein complex required for the process of V(D)J recombination during which the variable regions of immunoglobulin and T cell receptor genes are assembled in developing B and T lymphocytes.

RAG1

Recombination activating gene 1
It arises mainly from genetic recombination of the DNA encoded segments in individual somatic T cells by somatic V(D)J recombination using RAG1 and RAG2 recombinases.
The protein encoded by this gene is involved in antibody and T-cell receptor V(D)J recombination.

TRA (gene)

TRATRA@TCRA
In humans, in 95% of T cells the TCR consists of an alpha chain and a beta chain (encoded by TRA and TRB, respectively), whereas in 5% of T cells the TCR consists of gamma and delta chains (encoded by TRG and TRD, respectively).
It contributes the alpha chain to the larger TCR protein (T-cell receptor).

CD3 (immunology)

CD3CD3+antigens, cd3
The TCR is a disulfide-linked membrane-anchored heterodimeric protein normally consisting of the highly variable alpha and beta chains expressed as part of a complex with the invariant CD3 chain molecules. The complex contains both α and β chains, forming the ligand-binding site, and the signaling modules CD3δ, CD3γ, CD3ε and CD3ζ in the stoichiometry TCR α β - CD3εγ - CD3εδ - CD3ζζ.
These chains associate with the T-cell receptor (TCR) and the ζ-chain (zeta-chain) to generate an activation signal in T lymphocytes.

Thymus

thymus glandthymicmedulla
The recombination process that creates diversity in BCR (antibodies) and TCR is unique to lymphocytes (T and B cells) during the early stages of their development in primary lymphoid organs (thymus for T cells, bone marrow for B cells).
The cortex is the location of the earliest events in thymocyte development, where T-cell receptor gene rearrangement and positive selection takes place.

Antigen processing

processingprocessprocessed antigen
CDR3 is the main CDR responsible for recognizing processed antigen, although CDR1 of the alpha chain has also been shown to interact with the N-terminal part of the antigenic peptide, whereas CDR1 of the β-chain interacts with the C-terminal part of the peptide.

Antigen-presenting cell

antigen-presenting cellsantigen presenting cellantigen presenting cells
Each T cell expresses clonal TCRs which recognize a specific peptide loaded on a MHC molecule (pMHC), either on MHC class II on the surface of antigen presenting cells or MHC class I on any other cell type.
T cells may recognize these complexes using their T cell receptors (TCRs).

Cytotoxic T cell

cytotoxic T cellsCD8+cytotoxic T lymphocytes
Most cytotoxic T cells express T-cell receptors (TCRs) that can recognize a specific antigen.

Co-receptor

coreceptorco-receptors
The signal from the T-cell complex is enhanced by simultaneous binding of the MHC molecules by a specific co-receptor.
The CD receptor family typically act as co-receptors, illustrated by the classic example of CD4 acting as a co-receptor to the T cell receptor (TCR) to bind major histocompatibility complex II (MHC-II).

Lck

lymphocyte specific protein tyrosine kinase p56(lck)lymphocyte-specific protein tyrosine kinase
Intracellularly, the TCR co-receptor recruits essential molecules (e.g., LCK) involved in the signaling of the activated T lymphocyte to facilitate the CD3 signal transduction mechanism.
It associates with the cytoplasmic tails of the CD4 and CD8 co-receptors on T helper cells and cytotoxic T cells, respectively, to assist signaling from the T cell receptor (TCR) complex.

T helper cell

Th1Th2T helper cells
Like all T cells, they express the T cell receptor-CD3 complex.

CD247

ζ-chainCD3ζCD3-zeta
The complex contains both α and β chains, forming the ligand-binding site, and the signaling modules CD3δ, CD3γ, CD3ε and CD3ζ in the stoichiometry TCR α β - CD3εγ - CD3εδ - CD3ζζ.
T-cell receptor zeta, together with T-cell receptor alpha/beta and gamma/delta heterodimers and CD3-gamma, -delta, and -epsilon, forms the T-cell receptor-CD3 complex.