Substance P Signaling Contributes to Granuloma Formation in Taenia crassiceps Infection, a Murine Model of Cysticercosis

Abstract EN

Cysticercosis is an infection with larval cysts of the cestode Taenia solium.

Through pathways that are incompletely understood, dying parasites initiate a granulomatous reaction that, in the brain, causes seizures.

Substance P (SP), a neuropeptide involved in pain-transmission, contributes to inflammation and previously was detected in granulomas associated with dead T.

crassiceps cysts.

To determine if SP contributes to granuloma formation, we measured granuloma-size and levels of IL-1β, TNF-α, and IL-6 within granulomas in T.

crassiceps-infected wild type (WT) mice and mice deficient in SP-precursor (SPP) or the SP-receptor (neurokinin 1, NK1).

Granuloma volumes of infected SPP- and NK1-knockout mice were reduced by 31 and 36%, respectively, compared to WT mice (P<.05 for both) and produced up to 5-fold less IL-1β, TNF-α, and IL-6 protein.

Thus, SP signaling contributes to granuloma development and proinflammatory cytokine production in T.

crassiceps infection and suggests a potential role for this mediator in human cystercercosis.