Lack of galectin-3 alters the balance of innate immune cytokines and confers resistance to Rhodococcus equi infection

Luciana C. Ferraz, Emerson S. Bernardes, Aline F. Oliveira, Luciana P. Ruas, Marise L. Fermino, Sandro G. Soares, Adriano M. Loyola, Constance Oliver, Maria C. Jamur, Daniel K. Hsu, Fu-Tong Liu, Roger Chammas, Maria Cristina Roque-Barreira

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33 Scopus citations

Abstract

Galectin-3 is a β-galactoside-binding lectin implicated in the fine-tuning of innate immunity. Rhodococcus equi, a facultative intracellular bacterium of macrophages, causes severe granulomatous bronchopneumonia in young horses and immunocompromised humans. The aim of this study is to investigate the role of galectin-3 in the innate resistance mechanism against R. equi infection. The bacterial challenge of galectin-3-deficient mice (gal3-/-) and their wild-type counterpart (gal3+/+) revealed that the LD50 for the gal3-/- mice was about seven times higher than that for the gal3+/+ mice. When challenged with a sublethal dose, gal3-/- mice showed lower bacteria counts and higher production of IL-12 and IFN-γ production, besides exhibiting a delayed although increased inflammatory reaction. Gal3-/- macrophages exhibited a decreased frequency of bacterial replication and survival, and higher transcript levels of IL-1β, IL-6, IL-10, TLR2 and MyD88. R. equi-infected gal3+/+ macrophages showed decreased expression of TLR2, whereas R. equi-infected gal3-/- macrophages showed enhanced expression of this receptor. Furthermore, galectin-3 deficiency in macrophages may be responsible for the higher IL-1β serum levels detected in infected gal3-/- mice. Therefore galectin-3 may exert a regulatory role in innate immunity by diminishing IL-1β production and thus affecting resistance to R. equi infection.

Original languageEnglish (US)
Pages (from-to)2762-2775
Number of pages14
JournalEuropean Journal of Immunology
Volume38
Issue number10
DOIs
StatePublished - 2008

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Keywords

  • Bacterial infections
  • Galectin-3
  • IL-1β
  • Innate immunity
  • Toll-like receptor

ASJC Scopus subject areas

  • Immunology
  • Immunology and Allergy

Cite this

Ferraz, L. C., Bernardes, E. S., Oliveira, A. F., Ruas, L. P., Fermino, M. L., Soares, S. G., Loyola, A. M., Oliver, C., Jamur, M. C., Hsu, D. K., Liu, F-T., Chammas, R., & Roque-Barreira, M. C. (2008). Lack of galectin-3 alters the balance of innate immune cytokines and confers resistance to Rhodococcus equi infection. European Journal of Immunology, 38(10), 2762-2775. https://doi.org/10.1002/eji.200737986