Sigma-Aldrich Protein Delivery System Human Ifn-Gamm&

Protein delivery system, IFN-γ, PODS contains the polyhedrin protein co-crystalized with Human IFN-γ. Interferon γ (IFN-γ) is a type II interferon that is critical during adaptive and innate immune responses to infection. IFN-γ is produced by T cells and Natural Killer cells following antigen-specific activation. IFN-γ binds IFN-γ receptors (IFN-γ R1 and IFN-γ R2), which are expressed on most immune cells, to activate the JAK-STAT pathway. IFN-γ induced signaling increases the expression of class 1 major histocompatibility complex (MHC) molecules. Human IFN-γ is not cross-reactive with mouse IFN-γ.

PODS are composed of a bioactive cargo protein within a polyhedrin crystal lattice, with polyhedrin as the main protein. The 25 µg SKU size indicates the amount of bioactive cargo, typically 0.5% to 5% of the total protein. For instance, a 25 µg SKU at a 2% cargo loading contains 1.25 mg of total protein. PODS enable sustained release of cargo proteins when proteases degrade the polyhedrin scaffold. Growth factors are not bioavailable until released, and their concentration in media depends on the amount added and the release rate. In 10% serum, peak levels are usually reached within 24-48 hours, with about 20% of the cargo becoming soluble.

PODS often require lower concentrations than conventional growth factors, as they maintain effective levels. Pre-incubating with serum or proteases enhances availability, while conventional factors can be added for immediate effects. Optimal amounts should be determined empirically.

PODS is a registered trademark of Cell Guidance Systems Ltd