Skip to main content
  • Poster presentation
  • Open access
  • Published:

IFNγ prolongs survival in experimental Escherichia coli pyelonephritis: implications for favorable phagocytosis


IFNγ is a promising immunomodulator in sepsis because it is thought it may reverse immunoparalysis and improve phagocytosis. Its effect was investigated in experimental pyelonephritis and sepsis.


Experimental pyelonephritis by Escherichia coli was induced in 18 rabbits after ligation of the right pelvo-ureteral junction and infusion of one 1 × 107 log-phase cfu/ml inoculum above the ligation. Animals were assigned into 10 controls (group A) and into eight administered intravenously 0.1 μg/kg IFNγ 30 minutes after bacterial challenge (group B). Blood was sampled at serial time intervals; quantitative cultures were done; apoptosis of lymphocytes and of monocytes was assessed by flow cytometry; malondialdehyde (MDA) was estimated by the thiobarbiturate assay and passage through an HPLC system. After death, quantitative tissue cultures were done.


Median survival of group A was 3 days and of group B was 18 days (log-rank: 4.858, P = 0.028). Mean log10 of bacteria in blood for groups A and B at 2 hours was 1.59 and 1.21 (P = NS); at 4 hours 1.61 and 1.97 (P = NS); at 24 hours 1.28 and 1.02; and at 48 hours 1.29 and 1.00 (P = NS). Respective rates of apoptosis of lymphocytes at 2 hours were 17.1 and 22.2% (P = NS); at 4 hours 17.9 and 24.0% (P = NS); at 24 hours 18.3 and 21.9% (P = NS); and at 48 hours 20.5 and 22.8% (P = NS). Respective rates of apoptosis of monocytes at 2 hours were 32.8 and 36.0% (P = NS); at 4 hours 42.8 and 39.3% (P = NS); at 24 hours 54.5 and 62.1% (P = NS); and at 48 hours 52.5 and 64.3% (P = 0.042). Respective median serum MDA of groups A and B were 1.05 and 2.06 μmol/ml at baseline (P = NS); 0.93 and 2.54 μmol/ml at 2 hours (p: 0.028); 2.30 and 1.02 μmol/ml at 4 hours (P = NS); 1.47 and 2.05 μmol/ml at 24 hours (P = NS); and 1.71 and 1.85 μmol/ml at 48 hours (P = NS). Mean log10 of bacterial growth in the liver of group A and of group B on sacrifice was 3.47 and 1.32, respectively (P = 0.043); and in the right kidney was 5.78 and 1.94, respectively (P = 0.004).


IFNγ prolongs survival when administered after induction of experimental pyelonephritis by E. coli. Its effect is mediated through: enhanced phagocytosis as evidenced by increase of oxidant stress and decrease of tissue bacterial load; and modulation of inflammation as evidenced by increase of apoptosis of monocytes.

Author information

Authors and Affiliations


Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Cite this article

Katsaris, M., Adamis, T., Georgitsi, M. et al. IFNγ prolongs survival in experimental Escherichia coli pyelonephritis: implications for favorable phagocytosis. Crit Care 15 (Suppl 1), P250 (2011).

Download citation

  • Published:

  • DOI: