What does 4-1BB do?

Signaling via 4-1BB by anti-4-1BB activates various immune competent cells, leading to activation, cytokine induction, prevention of activation-induced cells death (AICD), upregulation of CTL activity, and increased survival (A).

What is a CD137 agonist?

The CD137/CD137L co-stimulation involves in controlling of monocyte numbers by amplification of monocyte-mediated proliferation of invariant NKT cells [23]. CD137 and/or CD137L agonists stimulate production of several inflammatory cytokines such as IL-6, TNF-α, and MCP-1 in adipocytes and macrophages [24].

Do T cells express CD40?

B cell CD40 directly activates cells, which can result in autoantibody production. T cells can also express CD40, with an increased frequency and amount of expression seen in CD4+ T lymphocytes of autoimmune mice, including T cells from mice with collagen-induced arthritis.

What does CTLA-4 do in T cells?

A protein found on T cells (a type of immune cell) that helps keep the body’s immune responses in check. When CTLA-4 is bound to another protein called B7, it helps keep T cells from killing other cells, including cancer cells. Some anticancer drugs, called immune checkpoint inhibitors, are used to block CTLA-4.

What type of receptor is CTLA-4?

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) (CD152) and CD28 are homologous receptors expressed by both CD4+ and CD8+ T cells, which mediate opposing functions in T-cell activation. Both receptors share a pair of ligands expressed on the surface of antigen-presenting cells (APCs).

Where is CD40 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.

Which cells have the CD40 receptor?

CD40 is constitutively expressed by antigen presenting cells, including dendritic cells, B cells and macrophages. It can also be expressed by endothelial cells, smooth muscle cells, fibroblasts and epithelial cells.

How does CTLA-4 inhibit T cells?

CTLA-4 and CD28 are coreceptors that bind to CD80 (B7-1) and CD86 (B7-2) to regulate T-cell activation. CD28 costimulation is required for T-cell activation, whereas CTLA-4 inhibits T-cell response by opposing the actions of CD28-mediated costimulation.

How does CTLA-4 inhibit T-cell activation?

After T-cell activation, CTLA-4 is stored in the intracellular vesicles, and recruited to the immunological synapse formed between T cells and APCs, and inhibits further activation of T cells by blocking signals initiated by T-cell receptors and CD28.