Assessment of eosinophil distribution, eotaxin, and CCR3 expression in Pirb^−/− mice. (A) Quantification of eosinophil distribution in the gastrointestinal tract of naive wild-type (WT) and Pirb^−/− mice. Eosinophils were identified by MBP-stained sections and quantified using digital morphometric analysis. Data represent means plus or minus SD of 4 or 5 random sections per mouse for 6 or 8 animals per group; *P < .05; **P < .01 when comparing Pirb^−/− and wild-type mice. Eso indicates esophagus. (B) The levels of eotaxin-1 and eotaxin-2 were assessed in small intestinal homogenates of WT and Pirb^−/− mice using a commercial ELISA. Data represent mean plus or minus SD of homogenates from 8 mice. ns indicates nonsignificant. (C) The expression of CCR3 as assessed by FACS on intestinal eosinophils from WT and Pirb^−/− mice. MFI indicates mean fluorescent intensity. Data represent n = 4 experiments. Error bars represent SD.