The serum levels of IFN-α and β were measured using the VeriKine mouse IFN-α and β ELISA kit (PBL Interferon Source, Piscataway, NJ, USA). The detection limit of mouse IFN-α and β ELISAs were 12.5 and 15.6 pg/ml, respectively. Serum levels of other cytokines (IL-1α, IL-1β, IL-2, IL-6, IL-10, TNF-α, and IFN-γ) were quantified using Luminex multiplex detection assay using antibody-coated magnetic beads (R&D Systems, Minneapolis, MN, USA).