Figure 5
Interleukin-1β (IL-1β) expression by infiltrating neutrophils in colitis-associated cancer (CAC) lesions is dependent on the commensal flora. (a) Commensal microbiota were left untreated or were eradicated by antibiotic treatment before CAC induction, and then at day 100 of CAC induction, the colons were isolated and stained with anti-Gr-1 antibody for detection of neutrophils. The data shown are representative of those obtained in six sets of mice. (b) Neutrophils infiltrating the colon tissues of mice with or without commensal eradication were isolated and IL-1β mRNA levels were measured by quantitative reverse-transcriptase–polymerase chain reaction (RT–PCR). Five pairs of mice were analyzed. (c) Neutrophils infiltrating the colon of TLR4−/− or wild-type mice that underwent CAC induction were isolated and IL-1β mRNA levels were measured by quantitative RT–PCR. Five pairs of mice were analyzed. (d) Neutrophils from the spleen of naive mice were isolated by fluorescence-activated cell sorting (FACS) and stimulated with LPS (20 ng ml−1) for 48 h, and then IL-1β protein (left) and mRNA (right) levels were measured by enzyme-linked immunosorbent assay (ELISA) or quantitative RT–PCR. **P<0.01; ***P<0.001.
