Description
Interleukin-18 (IL-18), also known as IL-1F4, is a proinflammatory cytokine that belongs to the IL-1 superfamily and is produced by macrophages and other cells. It is expressed as a 24 kDa precursor by endothelial and epithelial cells, keratinocytes, gamma δ T cells, and phagocytes. Mature human IL-18 shares approximately 63% amino acid sequence identity with mouse and rat IL-18. IL-18 activation is induced by infection or tissue damage and leads to disease pathology in chronic inflammation. In the presence of IL-12 or IL-15, IL-18 enhances anti-viral Th1 immune responses by inducing IFN-gamma production and the cytolytic activity of CD8+ T cells and NK cells. IL-18 induces the antigen-independent production of IL-17 by gamma δ T cells and CD4+ T cells. IL-18 also promotes myeloid dendritic cell maturation and triggers neutrophil respiratory burst. In the absence of IL-12 or IL-15, IL-18 promotes production of the Th2 cytokines IL-4 and IL-13 by CD4+ T cells and basophils. IL-18 induces the antigen-independent production of IL-17 by gamma δ T cells and CD4+ T cells. IL-18 also promotes myeloid dendritic cell maturation and triggers neutrophil respiratory burst. In cancer, IL-18 has shown a variety of activities, including enhancing anti-tumor immunity, inhibiting or promoting angiogenesis, and promoting tumor cell metastasis.
Molecular Weight
Approximately 18.2 kDa.
AA sequence
YFGKLESKLS VIRNLNDQVL FIDQGNRPLF EDMTDSDCRD NAPRTIFIIS MYKDSQPRGM AVTISVKCEK ISTLSCENKI ISFKEMNPPD NIKDTKSDII FFQRSVPGHD NKMQFESSSY EGYFLACEKE RDLFKLILKK EDELGDRSIM FTVQNED
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Purity
> 95% by SDS-PAGE analyses.
Biological Activity
Test in processing.
Endotoxin
Less than 0.1 EU/μg of rHuIL-18 as determined by LAL method.
Formulation
Lyophilized from a 0.2 μm filtered solution in PBS, pH 7.0.
Reconstitution
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1% BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20℃. Further dilutions should be made in appropriate buffered solutions.