IL-7 is an important cytokine for B and T cell development. IL-7 and the hepatocyte growth factor (HGF) form a heterodimer that functions as a pre-pro-B cell growth-stimulating factor. IL-7 is found to be a cofactor for V(D)J rearrangement of the T cell receptor beta (TCRB) during early T cell development. IL-7 can be produced by intestinal epithelial and epithelial goblet cells and may serve as a regulatory factor for intestinal mucosal lymphocytes. Knockout mice studies suggested that this cytokine plays an essential role in lymphoid cell survival.

Expression System
Escherichia coli

Sequence
MDCDIEGKDGKQYESVLMVSIDQLLDSMKEIGSNCLNNEFNFFKRHICDANKEGMFLFRAARKLRQFLKMNSTGDFDLHLLKVSEGTTILLNCTGQVKGRKPAALGEAQPTKSLEENKSLKEQKKLNDLCFLKRLLQEIKTCWNKILMGTKEH with polyhistidine tag at the C-terminus

Species
Human

Tag
polyhistidine tag at the C-terminus

Endotoxin Level
<0.1 EU per 1 μg of the protein by the LAL method.

Activity
Measured in a cell proliferation assay using PHA-activated human peripheral blood lymphocytes (PBMC). The ED₅₀ for this effect is <0.8 ng/mL. The specific activity of recombinant human IL-7 is > 7 x 10⁸ IU/mg.

Purity
>95% as determined by SDS-PAGE. Ni-NTA chromatography

Formulation
The protein was lyophilized from a solution containing 1X PBS, pH 8.0.

Reconstitution
It is recommended to reconstitute the lyophilized protein in sterile H₂O to a concentration not less than 100 μg/mL and incubate the stock solution for at least 20 minutes to ensure sufficient re-dissolved.

SDS-PAGE analysis of recombinant human IL-7