Description: This MM27-7B1 monoclonal antibody reacts with the p28 subunit of Interleukin-27 (IL-27), which is a member of the IL-12 family. IL-27 is a heterodimer of the subunits EBI3 (Epstein-Barr Virus Induced Gene 3), which is homologous to the p40 subunit shared by IL-12 and IL-23, and p28 (IL-30), which is homologous to p35. It is produced by activated dendritic cells and macrophages in response to TLR ligands and inflammatory cytokines.
The IL-27 receptor shares one subunit, gp130, with other members of the IL-6 family. The subunit WSX-1 (IL-27R alpha, TCCR) is unique to IL-27 and is believed to be the only part of the receptor that interacts with the cytokine. The IL-27R is most abundantly expressed on activated T-cells and NK cells, although expression has also been shown on B-cells and naïve T-cells. IL-27R activation leads to the phosphorylation of Jak/STAT proteins, with STAT1 and STAT3 being critical to the function of IL-27. IL-27 has been shown to have both pro-inflammatory and anti-inflammatory effects. It influences the commitment of CD4+ T-cells toward the Th1 lineage by inducing the expression of the T-bet transcription factor and the upregulation of IL-12R beta2. Its anti-inflammatory functions include the suppression of Th2 and Th17 proliferation and differentiation. Susceptibility to T-cell mediated autoimmunity has been observed in WSX-1 knockout mice.
Recent evidence suggests that the p28 subunit may also be secreted independently of EBI3 and have functions distinct to the IL-27 heterodimer. It is believed to not only antagonize the activity of IL-27, but also inhibit signaling of other gp130 ligands, such as IL-6 and IL-11.