FIG 9.

Host factor mRNA expression in microdissected samples of nasopharyngeal mucosa harvested during the transitional phase of infection in nonvaccinated cattle. IFN-λ, IRF-7, CXCL10, IFN-γ, and IL-10 mRNA expression levels in microdissected tissue compartments of nasopharyngeal mucosa from FMDV-negative (A) (n = 3) and FMDV-positive (B) (n = 5) cattle euthanized at 10, 14 or 21 dpi, corresponding to the period of divergence to carrier versus noncarrier status, were measured by qRT-PCR and are reported as the mean fold change ± SEM within each animal category. The expression levels are normalized to those of a housekeeping gene (GAPDH) and are relative to baseline levels established from similar analyses of tissues from noninfected cattle. Animals that had recently cleared the infection (A) (virus negative) had significantly higher levels of IFN-λ mRNA expression in follicle-associated epithelium (FAE) (*, Holm's method-adjusted P value, ≤0.05) and significantly lower levels of IL-10 mRNA expression in subepithelial lymphoid follicles (LF) (***, Holm's method-adjusted P value, ≤0.001) than virus-positive animals.