Figure 2
Neutrophils infiltrating into colitis-associated cancer (CAC) lesions highly express interleukin-1β (IL-1β). (a) Colon tissues from CAC-bearing mice or naive littermates were dissected and cultured in serum-free medium for 24 h, and then the supernatants were collected and IL-1β levels were measured by enzyme-linked immunosorbent assay (ELISA). Ten pairs of mice were analyzed. (b) Immune cells in the lamina propria (LP) of CAC-bearing or naive mice were sorted by staining for Gr-1 and CD11b and divided into four subpopulations (left panel): Gr-1−CD11b−, Gr-1hiCD11b+, Gr-1+CD11b−, and Gr-1low/−CD11b+, and then IL-1β mRNA levels in these cells were determined by quantitative reverse-transcriptase–polymerase chian reaction (RT–PCR). Six pairs of mice were analyzed. (c) LP-residing Gr-1hiCD11b+ and Gr-1low/−CD11b+ subsets were sorted as above and lysed, and then pro-IL-1β levels were determined by western blotting. The data shown are representative of those obtained in five independent experiments. (d) Spleen and colon tissues of CAC-bearing or naive mice were isolated and neutrophils (Gr-1hiCD11b+) in these tissues sorted by fluorescence-activated cell sorting (FACS), and then IL-1β mRNA levels were determined by quantitative RT–PCR. Five pairs of mice were analyzed. GAPDH, glyceraldehyde-3-phosphate dehydrogenase; ND, not detected. **P<0.01; ***P<0.001.
