Toll-like receptors (TLRs) recognise pathogen-derived molecules and influence
immunity to control
parasite infections. This study aimed to evaluate the
mRNA expression of TLRs 2 and 4, the expression and
production of the
cytokines interleukin (IL)-12,
interferon (IFN)-γ,
tumor necrosis factor (TNF)-α,
IL-17,
IL-10 and
transforming growth factor (TGF)-β and the
production of
nitric oxide (NO) in the
spleen of
mice infected with
Leishmania chagasi. It also aimed to evaluate any correlations between
mRNA expression TLR2 and 4 and
cytokines and NO
production.
Infection resulted in increased TLR2-4,
IL-17, TNF-α and TGF-β
mRNA expression during early
infection, with decreased expression during late
infection correlating with
parasite load. IFN-γ and
IL-12 mRNA expression decreased at the peak of parasitism.
IL-10 mRNA expression increased throughout the entire
time period analysed. Although TGF-β, TNF-α and
IL-17 were highly produced during the initial phase of
infection, IFN-γ and
IL-12 exhibited high
production during the final phase of
infection.
IL-10 and NO showed increased
production throughout the evaluated
time period. In the acute phase of
infection, there was a positive correlation between TLR2-4, TNF-α,
IL-17, NO,
IL-10 and TGF-β expression and
parasite load. During the chronic phase of
infection, there was a positive correlation between TLR2-4, TNF-α,
IL-17 and TGF-β expression and
parasite load. Our data suggest that
infection by L. chagasi resulted in modulation of TLRs 2 and 4 and
cytokines.