Figure 1.

Pam₂CSK₄ (TLR2/6) and ODN2395 (TLR9) synergistically inhibit parainfluenza virus replication in vivo. Guinea pigs were pretreated simultaneously with Pam₂CSK₄ (4 nmol) and ODN2395 (1 nmol), or with PBS vehicle, administered as an aerosol directly into the trachea (Tracheal), or as a nasal solution (Nasal), 24 hours before parainfluenza virus infection. Parainfluenza RNA from lung homogenates was quantified by RT-PCR, 4 days after infection. Both tracheal and nasal Pam2/ODN pretreatment inhibited virus replication, although the effect of nasal Pam2/ODN fell short of statistical significance (tracheal, Pam2/ODN, n = 12; PBS, n = 11; *P < 0.05; nasal, Pam2/ODN, n = 6; PBS, n = 10; ^#P = 0.08). Viral titers were normalized to 18S RNA and transformed to tissue culture infectious dose (TCID) 50 titers using a parainfluenza standard curve quantified by rhesus monkey kidney cell titration. Data shown represent the means ± standard errors of the mean.