59 Hence, SOCS proteins do not simply regulate https://www.selleckchem.com/products/wnt-c59-c59.html CD4+ T-cell commitment by inhibiting specific JAK/STAT responses, but rather, they adjust the balance between each lineage, suggesting that they might play an essential role in the regulation of CD4+ T-cell plasticity. It will be important to determine the relative expression of each SOCS in the context of human CD4+ T-cell polarization and ascertain whether these proteins might represent potential targets to medicate the growing allergy and autoimmune disease burden observed in recent decades. The authors

have no conflicts of interest to disclose. “
“The recognition by CD4+ T cells of peptides bound to class II MHC (MHCII) molecules expressed on the surface of antigen-presenting cells is a key step in RAD001 the initiation of an adaptive immune response. Presentation of peptides is the outcome of an intracellular selection process occurring in dedicated endosomal compartments involving, among others, an MHCII-like molecule named HLA-DM (DM). The impact of DM on the epitope selection machinery has been known for more than 15 years. However, the mechanism by which DM skews the presented

repertoire in favour of kinetically stable complexes has remained elusive. Here, a review of the most recent observations in the field is presented, ASK1 pointing to the possibility that DM decides the survival of a peptide–MHCII complex (pMHCII) on the basis of its conformational flexibility, which is a function of the ‘tightness’ of interaction between the peptide and the MHCII at a specific region of the binding site. Class II MHC (MHCII) molecules are transmembrane heterodimeric proteins expressed on the surface of antigen-presenting cells, and they initiate or propagate immune responses by presenting antigenic peptides to CD4+ T lymphocytes.[1]

The MHCII molecules feature a high level of polymorphism, predominantly restricted to the peptide-binding site. This groove-shaped domain is the main structural characteristic of the MHCII and defines its function. Each individual expresses a small number of different MHCII molecules. Hence, each of these must be able to bind a large number of different peptides to ensure an immune response against many possible pathogens.[2] The MHCII-restricted presentation of peptides to CD4+ T cells can be considered the outcome of an intracellular selection process. MHCII molecules are transported from the endoplasmic reticulum through the Golgi to the MHCII compartment (MIIC) as complexes with the chaperone protein invariant chain (Ii).[3, 4] Ii stabilizes the nascent MHCII and prevents the binding of other endoplasmic reticulum-resident polypeptides.