Leukosialin also known as sialophorin or CD43 (
cluster of differentiation
The cluster of differentiation (also known as cluster of designation or classification determinant and often abbreviated as CD) is a protocol used for the identification and investigation of cell surface molecules providing targets for immunophen ...
43) is a
transmembrane
A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequentl ...
cell surface
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
that in humans is encoded by the ''SPN'' (
sialo
phori
n)
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
Function
Sialophorin (leukosialin) is a major sialoglycoprotein on the surface of human
T lymphocyte
A T cell is a type of lymphocyte. T cells are one of the important 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 rec ...
s,
monocyte
Monocytes are a type of leukocyte or white blood cell. They are the largest type of leukocyte in blood and can differentiate into macrophages and conventional dendritic cells. As a part of the vertebrate innate immune system monocytes also inf ...
s,
granulocyte
Granulocytes are
cells in the innate immune system characterized by the presence of specific granules in their cytoplasm. Such granules distinguish them from the various agranulocytes. All myeloblastic granulocytes are polymorphonuclear. They ha ...
s, and some
B lymphocyte
B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or ...
s, which appears to be important for immune function and may be part of a physiologic ligand-receptor complex involved in T-cell activation.
Clinical significance
Defects in the CD43 molecule are associated with the development of
Wiskott–Aldrich syndrome
Wiskott–Aldrich syndrome (WAS) is a rare X-linked recessive disease characterized by eczema, thrombocytopenia (low platelet count), immune deficiency, and bloody diarrhea (secondary to the thrombocytopenia). It is also sometimes called the eczem ...
.
It also appears in about 25% of intestinal MALTomas. Using
immunohistochemistry
Immunohistochemistry (IHC) is the most common application of immunostaining. It involves the process of selectively identifying antigens (proteins) in cells of a tissue section by exploiting the principle of antibodies binding specifically to an ...
, CD43 can be demonstrated in the paracortical T-cells of healthy lymph nodes and tonsils; it is also positive in a range of lymphoid and myeloid tumours. Although it is present in over 90% of T-cell
lymphoma
Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlar ...
s, it is generally less effective at demonstrating this condition than is
CD3 antigen. However, it may be useful as part of a panel to demonstrate B-cell
lymphoblastic lymphoma, since the malignant cells in this condition are often CD43 positive, and may be difficult to stain with other antibodies. Because it stains granulocytes and their precursors, it is also an effective marker for
myeloid tumours.
Interactions
CD43 has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with
EZR and
Moesin
Moesin is a protein that in humans is encoded by the ''MSN'' gene.
Moesin (for membrane-organizing extension spike protein) is a member of the ERM protein family which includes ezrin and radixin. ERM proteins appear to function as cross-linkers ...
.
References
Further reading
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
External links
*
*
Clusters of differentiation
00
{{membrane-protein-stub