Cytokine and Chemokine Expression in Kidneys during Chronic Leptospirosis in Reservoir and Susceptible Animal Models

PLoS One. 2016 May 24;11(5):e0156084. doi: 10.1371/journal.pone.0156084. eCollection 2016.

Abstract

Leptospirosis is caused by pathogenic spirochetes of the genus Leptospira. Humans can be infected after exposure to contaminated urine of reservoir animals, usually rodents, regarded as typical asymptomatic carriers of leptospires. In contrast, accidental hosts may present an acute form of leptospirosis with a range of clinical symptoms including the development of Acute Kidney Injury (AKI). Chronic Kidney Disease (CKD) is considered as a possible AKI-residual sequela but little is known about the renal pathophysiology consequent to leptospirosis infection. Herein, we studied the renal morphological alterations in relation with the regulation of inflammatory cytokines and chemokines, comparing two experimental models of chronic leptospirosis, the golden Syrian hamster that survived the infection, becoming carrier of virulent leptospires, and the OF1 mouse, a usual reservoir of the bacteria. Animals were monitored until 28 days after injection with a virulent L. borgpetersenii serogroup Ballum to assess chronic infection. Hamsters developed morphological alterations in the kidneys with tubulointerstitial nephritis and fibrosis. Grading of lesions revealed higher scores in hamsters compared to the slight alterations observed in the mouse kidneys, irrespective of the bacterial load. Interestingly, pro-fibrotic TGF-β was downregulated in mouse kidneys. Moreover, cytokines IL-1β and IL-10, and chemokines MIP-1α/CCL3 and IP-10/CXCL-10 were significantly upregulated in hamster kidneys compared to mice. These results suggest a possible maintenance of inflammatory processes in the hamster kidneys with the infiltration of inflammatory cells in response to bacterial carriage, resulting in alterations of renal tissues. In contrast, lower expression levels in mouse kidneys indicated a better regulation of the inflammatory response and possible resolution processes likely related to resistance mechanisms.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Load
  • Chemokines / metabolism*
  • Cytokines / metabolism*
  • Disease Models, Animal
  • Gene Expression Regulation
  • Humans
  • Kidney / immunology
  • Kidney / pathology
  • Leptospira / pathogenicity*
  • Leptospirosis / complications
  • Leptospirosis / immunology
  • Leptospirosis / pathology*
  • Mesocricetus
  • Mice
  • Renal Insufficiency, Chronic / immunology
  • Renal Insufficiency, Chronic / microbiology*

Substances

  • Chemokines
  • Cytokines

Grants and funding

The research position of M.M. is financed by the Government of New Caledonia. This program is co-funded by the French Ministry of Research and Technology, Institut Pasteur de Nouvelle-Calédonie, and Institut Pasteur de Paris. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.