In experiments with anti-F1 antibodies, IL-10 was downregulated, potentially due to reduced TLR2-LcrV interaction and because the F1 capsule hinders TLR4 activation by LPS.65 The level of IL-10 upregulation coupled with increased levels of internalized bacteria at 2 h post-infection, as well as IgG1 subclass, appear to correlate with in vivo protection with anti-LcrV antibodies. The gene discussed is TLR4; the disease is infection.