Fig. 6. Human influenza infection upregulates TLR9 ligands in circulating blood:

Plasma samples were obtained from patients with influenza infection and control subjects without any respiratory infections. The total number of subjects in each group and demographics are shown in Fig. 6A. The overall TLR9 activity of plasma was measured using reporter cell line (B). The levels of mtDNA were measured using qPCR-based assay (C). Plasma TLR9 activity (D) and mtDNA levels (E) were compared between those admitted to medical intensive care unit (MICU) and those remained hospitalized without the need of MICU, as marker of disease severity. *, P<0.05, ** = P<0.01, **** = P<0.001 using Mann-Whitney test.