RNA was extracted from lung samples using the RNA GenElute kit (Sigma-Aldrich, St Louis, MO, USA). Quantitative PCR was performed using IQ Sybergreen Supermix (Bio-Rad, Hercules, CA, USA). Melting curves were performed to ensure the presence of a single amplicon. The following primers were used: rTlr2, forward 5’-TGT CTG TCA CCG AAC CGA ATC CAC-3’ and reverse 5’-TCA GGT TTT TCA GCG TCA GCA GGG-3’ ; and rGapdh, forward 5’-ATG TTT GTG ATG GGC GTG AAC C-3’ and reverse 5’-CCC AGC ATC GAA GGT AGA GGA-3’.