systemic lupus erythematosus (SLE) An autoimmune disease in which autoantibodies against DNA, RNA, and proteins associated with nucleic acids form immune complexes that damage small blood vessels, especially in the kidney.
T10, T22 Murine MHC class Ib genes expressed by activated lymphocytes and recognized by a subset of γ:δ T cells.
T lymphocytes (T cells) See T cell.
TAB1, TAB2 An adaptor complex that binds K63 linked polyubiquitin chains. TAB1/2 complex with TAK1, targeting TAK1 to signaling scaffolds where it phosphorylates substrates such as IKKα.
TACE (TNF-α-converting enzyme) A protease responsible for cleavage of the membrane-associated form of TNF-α, allowing cytokine release into its soluble form that can enter the systemic circulation.
TACI A receptor for BAFF expressed on B cells that activates the canonical NFκB pathway.
tacrolimus An immunosuppressant polypeptide drug that binds FKBPs and inactivates T cells by inhibiting calcineurin, thus blocking activation of the transcription factor NFAT. Also called FK506.
TAK1 A serine-threonine kinase that is activated by phosphorylation by the IRAK complex, and that activates downstream targets such as IKKβ and MAPKs.
talin An intracellular protein involved in the linkage of activated integrins, such as LFA-1, to the cytoskeleton to allow changes in cellular motility and migration, such as in the diapedesis of neutrophils across the vascular endothelium.
TAP1, TAP2 Transporters associated with antigen processing. ATP-binding cassette proteins that form a heterodimeric TAP-1:TAP-2 complex in the endoplasmic reticulum membrane, through which short peptides are transported from the cytosol into the lumen of the endoplasmic reticulum, where they associate with MHC class I molecules.
tapasin TAP-associated protein. A key molecule in the assembly of MHC class I molecules; a cell deficient in this protein has only unstable MHC class I molecules on the cell surface.
Tbet A transcription factor active in many immune cell types but most typically associated with ILC1 and TH1 function.
TBK1 (TANK-binding kinase) A serine-threonine kinase activated during signaling by TLR-3 and MAVS and serving to phosphorylate and activate IRF3 for induction of type I interferon gene expression.
T cell, T lymphocyte One of the two types of antigen-specific lymphocytes responsible for adaptive immune responses, the other being the B cells.
T cells are responsible for the cell-mediated adaptive immune reactions. They originate in the bone marrow but undergo most of their development in the thymus. The highly variable antigen receptor on T cells is called the T-cell receptor and recognizes a complex of peptide antigen bound to MHC molecules on cell surfaces. There are two main lineages of T cells: those carrying α:β receptors and those carrying γ:δ receptors. Effector T cells perform a variety of functions in an immune response, acting always by interacting with another cell in an antigen-specific manner. Some T cells activate macrophages, some help B cells produce antibody, and some kill cells infected with viruses and other intracellular pathogens.
T-cell antigen receptor See T-cell receptor.
T-cell areas Regions of peripheral lymphoid organs that are enriched in naive T cells and are distinct from the follicles. They are the sites at which adaptive immune responses are initiated.
T-cell plasticity Flexibility in the developmental programming of CD4 T cells such that effector T-cell subsets are not irreversibly fixed in their function or the transcriptional networks that underpin those functions.