Interaction between IL-1RI and the GluN2B subunit of NMDA receptors. A: Total homogenate was immunoprecipitated (i.p.) with antibodies against IL-1RI, GluA1 or GluN2B, and the presence of GluN2B, IL-1RI, PSD-95, IL-1RAcP and MyD88 in the immunocomplex was evaluated by means of western blot. IL-1RI, IL-1RAcP and MyD88 co-precipitated with GluN2B but not with GluA1. (*) Nonspecific bands were detected in the No IgG lane. B: GST-IL-1R(CD) and GST-PSD-95(PDZ1-2) fusion proteins, and GST alone were incubated in a pull-down assay with total homogenate from rat hippocampus. The western blot analysis was performed using the GluN2B antibody. C: Hippocampal cultures were exposed in the absence or the presence of IL-1β (30 minutes, 0.05 ng/ml) or NMDA (10 minutes, 50 μM). Neuronal lystes were immunoprecipitated with anti-IL-1RI, and the presence of GluN2B and IL-1RI in the immunocomplex was evaluated by means of western blot. Treatment with NMDA but not with IL-1β led to a significant increase in the IL-1β/GluN2B complex (p < 0.05 NMDA vs control).