Increased chemokine production in acute
experimental E. coli pyelonephritis
Brauner A1,
Hertting O1, Khalil A1, and Tullus K2
1Department
of Clinical Microbiology, MTC 2Astrid Lindgren Children’s
Hospital, Karolinska Hospital Stockholm, Sweden
Objective: To
investigate the production of the chemokines, MIP-2/IL-8, MCP-1 and RANTES
in mouse kidneys in acute E. coli pyelonephritis
and in human renal epithelial and primary mesangial cells after stimulation
with the same bacteria and IL-1b.
Methods: Acute
pyelonephritis was induced after transurethral inoculation with E. coli CFT073. Mice were sacrificed
at 24h, 48h and 6d. mRNA was studied in kidney sections using in situ hybridization. Protein levels were investigated
with ELISA in the supernatants from homogenized kidneys. Human renal
epithelial cell line (A498) and primary human mesangial cells were
stimulated with the same E. coli strain
and with IL-1b
for 0, 2, 6 and 24h. mRNA was studied using RT-PCR and protein levels in
the supernatants from the stimulated cells were investigated with ELISA.
Results: 24
hours after E. coli inoculation
mRNA MIP-2, MCP-1 and RANTES increased (135, 32 and 108 positive
cells/100mm2 respectively) compared to NaCl injected control
mice (35, 20 and 23 positive cells/100mm2; p<0.05
respectively). Similarly, maximum protein levels were observed at 24 hours,
(MIP-2: 2,320 pg/ml; MCP-1: 290 pg/ml and RANTES: 340 pg/ml; p<0.05
respectively vs untouched mice).
In renal epithelial as well as mesangial cells stimulated with E. coli CFT073 or with IL-1b
mRNA peaked at 6 hours for IL-8 and MCP-1 and at 24 hours for RANTES. All
chemokines had their maximum protein levels at 24h (p<0.05 vs non-stimulated cells).
Conclusion: A
significant increase of the studied chemokines was observed in experimental
acute E. coli pyelonephritis as
well as in renal epithelial and mesangial cells stimulated with either E. coli or IL-1b,
indicating their importance in acute pyelonephritis.