(n = 4) or 2.5 μg of recombinant IL-33
(rIL-33) (n = 5) in a total of 50 μl PBS. The
lungs were harvested 6 h later, minced, and homogenized in RLT buffer using a
Qiagen TissueRuptor. RNA was purified from each mouse lung homogenate (Qiagen
RNeasy Plus Mini Kit) and cDNA was prepared for each sample (Qiagen
RT2 First Strand Kit). RT2 Profiler PCR Array Mouse
Chemokines and Receptors kit (Qiagen) was used on pooled samples for
quantitative PCR (qPCR) array, which was performed on a CFX96 Real Time System
(Bio-Rad). Array data were analyzed using the data analysis web portal at
values were normalized to the housekeeping genes Gusb and
Hsp90ab1, after which ΔΔCTcalculations were performed and transcript fold change over PBS controls was
determined using the 2−ΔΔCTformula. Results for Ccl2, Ccl7, and
Ccl22 were confirmed by individual qPCRs performed on cDNA
from individual mice. PCR primers were as follows: HPRT, forward
5′-TGATCAGT-CAACGGGGGACA-3′, reverse
5′-TTCGAGAGGTCCTTTTCA-CCA-3′; CCL2, forward
5′-GGCCTGCTGTTCACAGTTGC-3′, reverse
5′-CCTGCTGCTGGTGATCCTCT-3′; CCL7, forward
5′-TGTGCCTGCTGCTCATAGCC-3′, reverse
5′-ACATAGCAGCATGTGGATGCATTG-3′; CCL22, forward
5′-CGCAAGCCTG-GCGTTGTTT-3′, reverse
5′-CCTCCCTGGACCACACCAGA-3′.