FIG. 2.

Low dietary protein increases day 10 disease and inflammation in B6 mice. Day 10 lung parameters are contrasted between high-disease (B6-LL) and low-disease outcomes for the main effects dietary protein (A), dietary antioxidants (B), and host genetics (mouse strain) (C). The ratios are log₂ transformed, and black bars represent significant differences, while gray bars indicate nonsignificance (n = 10 mice/group; P < 0.05 by Tukey HSD test). Protein reduction (LL versus HL diet) resulted in pronounced disease (lung weight [LW] increase) in B6 mice and prominently increased inflammation-associated transcripts such as IFN-γ, IL-10, IL-6, and TNF-α but essentially not cellular marker transcripts (A). Antioxidant reduction (LL versus LH diet) increased disease in B6 mice, with marginal transcript changes (B). The effect of host genetics showed the most profound differential of disease on the LL diet, with almost eightfold-increased levels of disease and 16-fold-increased levels of IFN-γ transcripts in B6 over A/J mice (C). Similar to the protein effect, the enhanced disease in B6 mice was accompanied by increased inflammatory transcripts but also cellular marker transcripts for a DTH response (F4/80, Tim3, and Tim3/GATA3). CPN, C. pneumoniae.