What happens in a person who lacks CD40 ligand on his or her T cells?
LACK of functional expression of CD40 ligand (CD40L) on T cells results in hyper-IgM syndrome (HIGMl), a human immunodeficiency associated with a severely impaired humoral immune response that is consistent with defects in B-cell responses1–3.
What does the interaction of CD40 ligand and CD40 receptor cause?
CD40L/CD40 interactions activate these cells by promoting the expression of molecules thought to be involved in atherosclerotic plaque formation, such as adhesion molecules, cytokines, matrix metalloproteinases, and tissue factor.
What does CD40 interact with?
Interactions. CD40 (protein) has been shown to interact with TRAF2, TRAF3, TRAF6, TRAF5 and TTRAP.
What happens when CD40 is stimulated?
CD40 signaling of B cells promotes germinal center (GC) formation, immunoglobulin (Ig) isotype switching, somatic hypermutation (SHM) of the Ig to enhance affinity for antigen, and finally the formation of long-lived plasma cells and memory B cells (14).
What is human CD40 immune cells?
CD40 is a Tumor Necrosis Factor Receptor superfamily member expressed by immune and non-immune cells. CD40:CD154 interactions mediate T-dependent B cell responses and efficient T cell priming. Thus, CD40 is a likely candidate to play roles in autoimmune diseases in which activated T and B cells cause pathology.
What is CD40 ligand mutation?
Mutations in the CD40 ligand (CD40L) gene (CD40LG) lead to X-linked hyper-IgM syndrome (X-HIGM), which is a primary immunodeficiency (PID) characterized by decreased serum levels of IgG and IgA and normal or elevated IgM levels.
What is CD40 antibody?
CD40, a stimulatory receptor and a member of the tumor necrosis factor (TNF) receptor superfamily, is expressed on various immune cells, such as macrophages, dendritic cells and various tumor cell types; it plays a key role in the activation of the immune system.
Where is CD40 ligand found?
The CD40LG gene provides instructions for making a protein called CD40 ligand, which is found on the surface of immune system cells known as T cells. CD40 ligand attaches like a key in a lock to its receptor protein, CD40, which is located on the surface of immune system cells known as B cells.
Where does affinity maturation occur?
Affinity maturation occurs within the GC, where somatically mutated BCRs undergo selection on antigen retained on FDCs [39,40]. Antigen is retained in the form of ICs and involves the interaction of both complement receptors and FcγRIIB with these ICs on FDCs. B cells also express both complement and FcγRIIB.
Can soluble CD40L ligand be used as a therapeutic target?
The Role of Soluble CD40L Ligand in Human Carcinogenesis Patients with neoplasia had higher circulating sCD40L levels and it is likely that sCD40L may have a predictive role. It is still unclear whether sCD40L can be used as a therapeutic target.
What does CD40L stand for?
CD40 ligand (CD40L), also known as CD154, is a protein that is primarily expressed on the surface of activated T cells and belongs to a member of the tumor necrosis factor superfamily. Lack of CD40L results in an inability to undergo immunoglobulin class switch and only class IgM antibodies can be generated.
What happens if there is no CD40L in the plasma membrane?
Lack of CD40L results in an inability to undergo immunoglobulin class switch and only class IgM antibodies can be generated. CD40L exists as a membrane-bound form with a molecular weight of 33 kDa and as a soluble form with a molecular weight of 18 kDa.
What is scd40l in platelets?
Soluble CD40L (sCD40L) is stored in platelet granules and thus its presence in the blood is a biomarker of platelet activation. sCD40L expression is known to be upregulated in atheroma-associated cells [139,140].