Table. Major CD antigens and their cellular distribution*

Table. Major CD antigens and their cellular distribution*

Cluster designation	Tissue distribution	Function
CD1	Cortical thymocytes
CD2	All T cells and NK cells	Ligand for CD58; pair (e.g. between T cell and antigen-presenting cell)
CD3	Found on all mature T cells	Signal transduction following antigen presentation
	Intimately associated with the T cell receptor
CD4	T-helper/inducer lymphocytes comprise circulating T cells	Interacts with class II MHC molecules associated with processed antigen fragments
CD5	T cells; also B cells	Ligand for CD72
CD8	Cytotoxic/suppressor T cells	Interacts with class I MHC molecules associated with processed antigen fragments
CD11a	Lymphocytes (especially memory T cells), granulocytes, monocytes and macrophages	Part of adhesion molecule LFA-1
CD14	Macrophages	Receptor for bacterial lipopolysaccharide
CD15 (also known as Lewis X)	Granulocytes	Ligand for selectins
CD16	Natural killer cells and macrophages	CD16 is a low-affinity Fc receptor involved in signal transduction
CD18	Leucocytes	Common β-chain of LFA family (beta integrins)
CD19	All mature B cells	Signal transduction
CD20	All mature B cells	Involved in cell activation; may be a calcium channel
CD21	Mature B cells, follicular dendritic cells, pharyngeal and cervical epithelial cells	Complement C3d receptor
CD23	B cells, macrophages, eosinophils	Low-affinity receptor for IgE
CD25	T, B cells, macrophages	IL-2 receptor
CD28	Activated T cells and some B cells	Activation of naive T cells
CD34	Precursors of haemopoietic cells	Unknown
CD36	Monocytes, platelets	GPIIIb
CD40	B cells	B-cell activation, induced by T-cell interaction
CD44	Leucocytes, RBCs, endothelium	Cell adhesion and migration, removal of apoptotic neutrophils by macrophages
CD45	All cells of a haemopoietic origin; also called leucocyte common antigen	Two isoforms, RO and RA. RO is associated with memory. Functions by cell signalling through the T-cell receptor; RA identifies naive cell
CD56	NK cell marker	Mediates cell adhesion
CD62	Endothelial cells, leucocytes and platelets (E-, L-, P-selectin)	Adhesion
CD72	All mature B cells	Ligand for CD5; involved in signalling
CD80/86	Antigen-presenting cells	Costimulatory ligands for CD28
CD95 (Fas Ag, APO-1)	Multiple cells	Induction of programmed cell death
CD103	Intraepithelial lymphocytes	Binds to E-cadherin

*This list is far from exhaustive and has been confined to CD types most commonly encountered in a clinical immunology setting
Cluster of differentiation (CD) classification

The CD nomenclature classifies over 300 molecules both within and outside the immune system, using monoclonal antibodies. As the surface molecule has many different epitopes (antibody-binding sites), several different antibodies may react (a cluster). As initially most of the surface molecules defined the stage of development of the cell, they were termed 'differentiation' molecules. The term CD therefore refers to a specific target molecule on a cell that is recognized by one or more antibodies and defines a particular cell type or function. A list of CD molecules that are commonly mentioned is given in.

Дата добавления: 2015-11-04