LEPR and infection: LEPR expression was specifically downregulated using siRNA treatment for 48h, then the recombinant human leptin (rLep) was added at 10 ng/mL (normal condition), and 100 ng/mL (hyperleptinemia) (Considine et al., 1996; Niskanen et al., 1997) for 24 hours before infection (Figure 10A).