TLR4 and Jaundice: Our results showed that TLR4−/− mice had significantly higher numbers of Leptospira in the blood and tissues, which were consistent with a previous report that intact TLR4 signaling was important in the control of tissue leptospiral burden.13, 14 Moreover, TLR4−/− mice presented more severe jaundice and higher bilirubin and AST levels compared with WT mice over the course of the disease, which was in accordance with the higher Leptospira burden and lesions in the liver of TLR4−/− mice that peaked on 2 dpi and remained at a relatively high level until 3 dpi.