Ad
related to: t cell receptor signaling
Search results
Results from the WOW.Com Content Network
Because T cells undergo positive selection in the thymus, there is a non-negligible affinity between self-pMHC and the TCR. Nevertheless, the T-cell receptor signaling should not be activated by self-pMHC so that endogenous, healthy cells are ignored by T cells.
T cells are one of the important types of white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface. T cells are born from hematopoietic stem cells, [1] found in the bone marrow.
On plasma membrane of a T cell there is the T-cell receptor (consists of α,β chains and multiple CD3 adaptor proteins), as well as molecules that induce signalling (tyrosine kinase Lck phosphorylates ITAMs in CD3 complex) and factors that inhibit signalling (tyrosine phosphatases CD45 and CD148).
The intracellular T cell signaling domain lies in the receptor's endodomain, inside the cell. [79] After an antigen is bound to the external antigen recognition domain, CAR receptors cluster together and transmit an activation signal. Then the internal cytoplasmic end of the receptor perpetuates signaling inside the T cell. [81]
CD2 was shown to prime naive T cells (T N) even without CD28 or TCR. [2] Also, CD27 is a receptor constitutively expressed on T N (its expression is downregulated upon TCR stimulation) and enhances T cell proliferation. [9] The differentiation of T helper cells (T H) into different subsets also partially depends on their co-stimulatory molecules.
ITAMs are important for signal transduction, mainly in immune cells. They are found in the cytoplasmic tails of non-catalytic tyrosine-phosphorylated receptors [7] such as the CD3 and ζ-chains of the T cell receptor complex, the CD79-alpha and -beta chains of the B cell receptor complex, and certain Fc receptors.
CD3 (cluster of differentiation 3) is a protein complex and T cell co-receptor that is involved in activating both the cytotoxic T cell (CD8+ naive T cells) and T helper cells (CD4+ naive T cells). [1] It is composed of four distinct chains. In mammals, the complex contains a CD3γ chain, a CD3δ chain, and two CD3ε chains.
The Linker for activation of T cells, also known as linker of activated T cells or LAT, is a protein involved in the T-cell antigen receptor signal transduction pathway which in humans is encoded by the LAT gene. [5] Alternative splicing results in multiple transcript variants encoding different isoforms. [6]
Ad
related to: t cell receptor signaling