Interleukin-12 receptor

Interleukin-12 receptor (IL-12R) is a type of protein that is found on the surface of certain immune cells. It is part of the cytokine receptor family and plays a crucial role in the immune response by binding to interleukin-12 (IL-12), a cytokine that stimulates the growth and function of T cells.

Structure

The IL-12R is composed of two subunits, IL-12Rβ1 and IL-12Rβ2, which are encoded by separate genes. Both subunits are necessary for the receptor to bind to IL-12 and transmit signals into the cell. The IL-12Rβ1 subunit is shared with the interleukin-23 receptor (IL-23R), while the IL-12Rβ2 subunit is unique to the IL-12R.

Function

The primary function of the IL-12R is to bind to IL-12 and initiate a series of intracellular signaling events. This leads to the activation of Janus kinase 2 (JAK2) and Tyrosine kinase 2 (Tyk2), which in turn activate the signal transducer and activator of transcription (STAT) proteins, specifically STAT4. Activated STAT4 then moves into the cell nucleus, where it promotes the transcription of genes that drive the differentiation of T cells into Th1 cells, a subtype of T cells that play a key role in cell-mediated immunity.

Clinical significance

Mutations in the genes encoding the IL-12R subunits can lead to primary immunodeficiency diseases, such as IL-12Rβ1 deficiency and IL-12Rβ2 deficiency. These conditions are characterized by an increased susceptibility to infections, particularly by mycobacteria and Salmonella. In addition, the IL-12R is a potential target for immunotherapy, as blocking its function can help to modulate the immune response in conditions such as autoimmune diseases and cancer.

See also

• Interleukin-12
• Cytokine receptor
• T cell
• Primary immunodeficiency