Anti IL-18  

Immunohistochemistry with Rabbit anti-Mouse IL-18 antibody showing IL-18 staining in inflammatory cells of the mucous corium of mouse colon at 20x and 40x. Slide A is a negative control. Slides B and C show staining. Formalin fixed/paraffin embedded sections were subjected to heat induced epitope retrieval (HIER) at pH 6.2 and then incubated with mouse anti-IL-18 antibody at 4.0 μg/ml for 60 minutes. The reaction was developed using MACH 4 universal AP polymer detection system and visualized with WARP RED.

Immunofluorescence microscopy of IL-18 in mouse colon sections. The transversing portion of the large intestine from DSS-exposed (Panel A) and -unexposed mice (Panel B) was excised, rinsed in PBS, and frozen on isopentane cooled with liquid nitrogen. Frozen sections (5 μm) were cut on a Leica CM 1850 cryostat. The slides were fixed for 10 min in 4% paraformaldehyde, air-dried, and incubated for 20 min in PBS supplemented with 10% normal goat serum. Sections were incubated in a 1:50 dilution of Rockland's rabbit anti-Mouse IL-18 antibody or 1 μg/ml nonimmune rabbit IgG (not shown) as negative control. The antibodies were diluted in PBS containing 1% bovine serum albumin. After an overnight incubation at 4°C, the sections were washed three times with 0.5% bovine serum albumin in PBS. The sections were then incubated with a secondary goat anti-rabbit antibody conjugated to Alexa488 (Molecular Probes) for 60 min at room temperature in the dark. Nuclei were counterstained blue using 1 μg/100 ml bisbenzimide. After staining, sections were washed and examined with the Leica DM RXA confocal laser scanning system and analyzed. Similar staining will occur with other systems.

In-vitro neutralization. Spleens were aseptically removed and cell suspensions were prepared. Cells were washed twice and resuspended in RPMI supplemented with 10% FBS. For cytokine measurement, spleen cells were cultured at 5 mln/mL in 24-well, flat-bottom culture plates in the presence of several dilutions of rabbit anti-murine IL-18 antibody (1:400; 1:200; 1:100; 1:50) and 100 ng/mL of LPS (a phenol-extracted preparation from Escherichia coli 055:B5, Sigma Chemical Co). Cultures were incubated at 37°C in a humidified atmosphere with 5% CO2. At the end of the incubation period, cultures were frozen at -70°C and subjected to 3 freeze-thaw cycles to obtain total cytokine levels. Before assaying, samples were centrifuged for 10 minutes at 10,000g to remove debris.