LTC4S and infection: Here, using the Line 19 strain of RSV, we observed steady Alox15 expression 3-6 days after infection, followed by a significant decrease in expression at day 12 p.i. In contrast to Alox15 expression, we observed significantly decreased mRNA transcripts of Ltc4s, mGst3, and Gstm4 – biosynthetic enzymes downstream of Alox15 for PCTR1 synthesis – when viral titers were highest at day 3 p.i. These transcriptional changes and the decreased lung tissue concentrations of protectins suggest that the biosynthetic pathway for protectins was suppressed by RSV in this model.