The iLite Human Type I Interferon Responsive Cells are engineered cells optimized to express Firefly Luciferase under the control of an IFN a/b responsive promoter. IFNa or IFNb bind to the IFN a/b receptor on the cell surface and activate the IFN a/b regulated Firefly Luciferase reporter gene construct. Normalization of cell counts and serum matrix effects is obtained by a second reporter gene, a Renilla Luciferase reporter gene construct, under control of a constitutive promoter. 

iLite Type I IFN Assay Ready Cells are growth arrested cells which are sensitive to human Type I Interferon. The cells can be used in a number of different assays for measuring the bioactivity of Type I Interferon or NAbs to IFN beta or NAbs to IFN alpha. The iLite IFN cells are the only commercially available cells capable of measuring either the bioactivity of type I interferon, NAbs to IFN beta or NAbs to IFN alpha.

Interferon alpha (IFNa) has been widely used to treat chronic viral hepatitis and a wide variety of malignant diseases, including hairy cell leukemia, basal cell carcinoma, chronic myeloid leukemia, and cutaneous T-cell lymphoma. Several different recombinant preparations of IFNa are available commercially; the most commonly used formulations include IFNa2a and IFNa2b. A number of studies have shown that development of anti-IFNa neutralizing antibodies (NAbs) is correlated with a loss of IFNa treatment efficacy.

Interferon beta (IFNb) is well established as first line therapy in relapsing/remitting multiple sclerosis. The occurrence of NAbs and binding antibodies (BAbs) to IFNb has been widely reported. Subjects with NAbs have shown reduced response to treatment with IFNb, having higher relapse rates, increased MRI activity and higher risk of disease progression. The frequencies and titers of NAbs vary depending on the preparation used, dose and frequency of administration and also the assay used to quantify them.