Fig. 2.

Anti-BmToll9 IgG blocks LPS-induced immune responses in B. mori larvae. Day 3 fifth-instar B. mori larvae were preinjected with purified anti-BmToll9^ecto IgG or preimmune IgG (control), and then injected with ultrapure LPS-K12, PGN-K12, or H₂O 1 h later. Larvae with no second injection served as a control (none). Hemolymph and fat body were collected 12 and 24 h after a second injection for antibacterial and qRT-PCR assays. (A) Representative inhibition zone assays using hemolymph and E. coli. (B) Mean diameter (mm) ± SEM of six inhibition zone assays. (C) Mean relative expression ± SEM of select antimicrobial peptide genes in fat body as determined by qRT-PCR. The expression of AMP genes in the fat body of larvae injected with preimmune IgG and no second injection (none) served as the reference for calculating the relative expression of each gene. Three biological replicates were generated for each treatment. Significant differences between the preimmune IgG and anti-BmToll9 IgG groups for each second injection treatment were determined by t test with significance indicated by asterisks: *P < 0.05, **P < 0.001, ***P < 0.0001; ns, not significantly different.