Cluster of Differentiation (CD) Flashcards
CD3
Found on T cells. Coreceptor for TCR: Important in signal transduction
CD4
T-helpers
CD4 is a co-receptor that assists the T cell receptor (TCR) in communicating with an antigen-presenting cell. Using its intracellular domain, CD4 amplifies the signal generated by the TCR by recruiting an enzyme, the tyrosine kinase Lck, which is essential for activating many molecular components of the signaling cascade of an activated T cell.
CD8
T-cytotoxic cells
The extracellular IgV-like domain of CD8-α interacts with the α3 portion of the Class I MHC molecule. This affinity keeps the T cell receptor of the cytotoxic T cell and the target cell bound closely together during antigen-specific activation. Cytotoxic T cells with CD8 surface protein are called CD8+ T cells. The main recognition site is a flexible loop at the α3 domain of an MHC molecule
CD19
B-cells (They have CD 19, 20 and 21)
CD and surface markers on Treg
CD25, CD103, Foxp3
CTLA-4
CTLA and B7 (aka CD80 or CD87) make a complex
CTLA4 or CTLA-4 (cytotoxic T-lymphocyte-associated protein 4), also known as CD152 (cluster of differentiation 152), is a protein receptor that, functioning as an immune checkpoint, downregulates immune responses. CTLA4 is constitutively expressed in Tregs but only upregulated in conventional T cells after activation. It acts as an “off” switch when bound to CD80 or CD86 on the surface of antigen-presenting cells.
CD56+
Natural Killer cells
also have CD16
CD25
Treg
Do γδTcell have CD4 or CD8?
No, just CD3 and γδTCR
CD14
Macrophages
CD16
Natural killer
also have CD56
CD79
Signal transduction moiety: A heterodimer called Ig-α/Ig-β in B-cell signaling. Together with CD 19 and CD 21
Which CD defect is present in Leukocyte adhesion deficiency?
CD18 (common B2 chain of integrins)
Leukocytes cannot migrate
Rare autosomal recessive disease
CD40
Costimulatory protein found on APC. Binding with CD40
Important in class switching.
CD40L (ligand) binding in the formation of B/T cell conjugation.
