TLR4 and leptospirosis: The role of TLR4 in the resistance of the mouse model has been extensively addressed: C3H/HeJ and TLR4-/- mice are sensitive to leptospirosis (Pereira et al., 1998; Nally et al., 2005; Viriyakosol et al., 2006; Chassin et al., 2009).