Cytokines

The interleukin-6 receptor (IL-6R) complex is composed of two membrane glycoproteins: the low affinity receptor and the signal transducing component. The soluble form of IL-6R (IL6-sR) is found in the urine of healthy adult humans and the serum of HIV positive individuals, as well as in the cell culture supernatants of stimulated PBMC. This soluble form of IL-6R results from either proteolytic cleavage from the membrane, or an isoform derived splice variant. Recombinant IL6-sR comprises a 161 amino acid fragment (20-357) corresponding to the mature IL6-sR protein and is expressed in E.

Interleukin 33 (IL-33) is a proimflammatory cytokine belonging to the IL-1 family. IL-33 is cleaved intracellularly, generating an N terminal and a C terminal fragment. The C terminal fragment corresponds to the mature IL-33 protein and mediates its biological effect by interacting with the IL-1 receptor, also known as ST2. Binding of mature IL-33 to this receptor activates NF-kappa-B and MAP kinases and induces the production of associated cytokines, in particular IL-4, IL-5 and IL-13, causing severe pathological changes in mucosal organs.

Interleukin-13 (IL-13) is a pleiotropic regulatory cytokine, which shares many of the properties of interleukin-4. IL-13 is produced primarily by activated T lymphocytes and acts via specific cell surface receptor complexes. Its biological activities include the stimulation of B-cell proliferation and differentiation and the regulation of inflammatory and immune responses. Recombinant Interleukin-13 comprises a 112 amino acid fragment (21-132) corresponding to the mature Interleukin-13 110R form of the protein and is expressed in E. coli with an amino-terminal hexahistidine tag.

Intereukin-10 (IL-10) inhibits the synthesis of a number of cytokines, including IFN-gamma, IL-2, IL-3, TNF and GM-CSF produced by activated macrophages and helper T-cells. Recombinant interleukin-10 comprises a 160 amino acid fragment (19-178) corresponding to the mature Interleukin-10 protein and is expressed in E. coli with an amino-terminal hexahistidine tag.

Inhibins and activins inhibit and activate, respectively, the secretion of follitropin by the pituitary gland. Inhibins/activins are involved in regulating a number of diverse functions such as hypothalamic and pituitary hormone secretion, gonadal hormone secretion, germ cell development and maturation, erythroid differentiation, insulin secretion, nerve cell survival, and embryonic axial development or bone growth (depending on their subunit composition). Inhibins appear to oppose the functions of activins. Inhibins are dimeric proteins, linked by one or more disulfide bonds.