What is the function of CD40L?
CD40L mediates a range of activities on B cells, including induction of activation-associated surface antigen, entry into cell cycle, isotype switching, Ig secretion, and memory generation. CD40–CD40L interaction also plays important roles in monocyte activation and DC maturation.
What is CD40L for T cells?
CD40L, or CD154, is canonically expressed on CD4+ T cells and it is a principal modulator of a wide range of humoral and cellular immune responses (1, 2). One of the primary functions of CD40L is the T cell-mediated activation of DCs and monocytes (3, 4), in a process known as DC licensing.
What does CD40 bind to?
CD40 binds its ligand CD40L, which is transiently expressed on T cells and other non-immune cells under inflammatory conditions. A wide spectrum of molecular and cellular processes is regulated by CD40 engagement including the initiation and progression of cellular and humoral adaptive immunity.
What is the importance of CD40L CD40 interaction with respect to activation of B cells?
CD40L/CD40 interaction in cellular immunity Among a multitude of cellular functions, CD40L regulates the costimulatory activity of APCs, inducing B cells to upregulate the expression of CD80 (B7. 1) and CD86 (B7. 2) and DCs to upregulate the expression of CD54 and CD86.
Where is CD40L 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.
What does it take to activate the cell that activates the T cell?
The T cell encounters a dendritic cell (DC) bearing its cognate peptide in an MHC molecule, and binds the peptide-MHC though CD3 and CD4 or 8. Subsequently, co-stimulation occurs through DC-bound CD86, CD80, OX40L and 4-1BBL. This induces full activation and effector function in the T cell.
What is CD40L a marker of?
CD40L is a costimulatory molecule and an early activation marker of T-lymphocytes.
What is CD86 a marker for?
Along with CD80, CD86 provides costimulatory signals necessary for T cell activation and survival. Depending on the ligand bound, CD86 can signal for self-regulation and cell-cell association, or for attenuation of regulation and cell-cell disassociation.
What are the effects of CD40 on B cells?
CD40 stimulation results in upregulation of CD80 and CD86 on human peripheral B cells as well as naïve, memory and GC B cells from human tonsil [ 28, 29 ]. CD40 signals also induce upregulation of CD95/Fas and major histocompatibility complex class II (MHCII) on human B cells [ [30], [31], [32] ].
Where are CD40L and CD4 + T cells expressed?
CD40 is known to be expressed on additional hematopoietic cells, such as monocytes and dendritic cells (DCs) where it promotes cell survival and cytokine production [ 10] and can also signal to induce activation, proliferation and cytokine production from CD40L expressing CD4+ T cells [ 11 ].
How is CD40 related to pro inflammatory cytokines?
Studies suggest that CD40 can signal with IL-4 to induce NFκB activation and IL-6 production by human B cells [ 37 ]. In concert with BCR signals, CD40 co-stimulates production of several pro-inflammatory cytokines including IL-6, TNFα and lymphotoxin-alpha [ 30 ].
How does CD40 affect the production of IL-12?
CD40 stimulation induces IL-12 production from naïve and memory tonsillar B cells [ 36 ]. Studies suggest that CD40 can signal with IL-4 to induce NFκB activation and IL-6 production by human B cells [ 37 ].