Exacerbated Skeletal Muscle Inflammation and Calcification in the Acute Phase of Infection by Mexican Trypanosoma cruzi DTUI Strain

Abstract EN

A murine model was used to study the histopathological aspects and cytokine expression levels in skeletal muscle provoked by the infection with Mexican TcI strains.

BALB/c mice were inoculated with the virulent Querétaro strain and the nonvirulent Ninoa strain.

Parasite numbers were counted in blood and skeletal muscle at different times post-infection, and real time-PCR expression levels of the cytokines IL-12, IL-4, IL-10, IFN-γ, and TNF-α were evaluated.

In the acute phase of infection, a high parasitic load, both in blood and skeletal muscle, was detected.

The histopathological analyses showed an exacerbated inflammation and granulomatous-like infiltrate with the Querétaro strain.

Interestingly, extensive calcification areas were observed in the skeletal muscle surrounded by inflammatory infiltrates.

TNF-α and IL-10 expression exhibited a significant increase at the peak of infection.

In summary, Querétaro strain, a Mexican TcI strain, is virulent enough to induce high inflammation and calcification in skeletal muscle of the hind limbs, which could be related to high expression levels of TNF-α.