Figure 9. Medullary DCs regulate the innate immunity against PN.

(A) Representative FACS plots of CXCL2 production by CD45⁺MHC-II⁺ cells in kidney cortex and medulla 3 hours after second UPEC instillation. Cells were incubated with brefeldin A for 4 hours at 37°C prior to staining. (B) Percentage of CXCL2-producing cells of CD45⁺MHC-II⁺CD11c⁺ cells in cortex (white squares) and medulla (black squares). (C) MFI for CXCL2 of cortical and medullary CXCL2⁺ DCs, representing CXCL2 production per cell. (D) CFUs per kidney in CX₃CR1^GFP/+ reporter mice and CX₃CR1^GFP/GFP-deficient mice 6 hours after second UPEC instillation. (E) Numbers of neutrophils (PMNs) per kidney in CX₃CR1^GFP/+ and CX₃CR1^GFP/GFP mice 6 hours after second UPEC instillation. (F) Representative histogram of CXCL2 staining (black line) of CD45⁺Ly6G⁺ neutrophils from CX₃CR1^GFP/+ and CX₃CR1^GFP/GFP mice 6 hours after second UPEC instillation, compared with isotype control (gray solid). Cells were incubated with brefeldin A for 4 hours at 37°C prior to staining. Data points represent individual mice; and results are representative of 2 to 3 individual experiments, with 6 mice per group. Statistical significance was analyzed by (B and C) Wilcoxon signed-rank test or (D and E) 2-tailed Mann-Whitney nonparametric test.