Fig. 1.

Experimental design for investigating the impact of Leptospira infection on renal immune responses. (A) Schematic view of the study of immune responses and bacterial colonization in the kidneys following infection with either pathogenic or nonpathogenic Leptospira spp. (B) The immune responses to Leptospira infection are characterized by the mRNA expression of pro-inflammatory cytokines (TNF-α and IL-6) and the anti-inflammatory cytokine IL-10. Representative renal histological findings in uninfected (C) and infected (D∼F) mice. These tissues were formalin-fixed and paraffin-embedded for histology and immunofluorescence study. Light microscopy of kidney tissues, stained with the hematoxylin and eosin (Magnification, 100 X). After infection at 28 days, inflammatory infiltration is observed in the nonpathogenic L. biflexa-infected (D) and pathogenic L. interrogans-infected (E) mice. (F) Bacterial adherence to the tubule lumen was found in the kidneys from mice infected with L. interrogans at 28 days post-infection. Confocal images of immunofluorescent staining (magnification of 400X). Anti-leptospiral LipL32 (green; white arrow) and DAPI staining (blue).