Fasciola hepaticaFh15 promote survival in a mouse septic shock model and downregulates inflammatory cytokines

Abstract

Abstract Parasitic helminths and helminth-derived molecules, possess an inherent anti-inflammatory capacity. Fasciola hepatica has been reported to decrease in vivo particular Th1 immune responses caused by concurrent bacterial infections. Studies have shown that some Fasciola hepatica’s excretory-secretory products has the capacity to reduce phagocytic activity, affect cell recruitment, and induce activation of alternative activated macrophages. We hypothesized that recombinant F. hepatica FABP (Fh15) may be an excellent target for the development of new anti-inflammatory drugs against sepsis. For this, we developed a mouse model of septic shock to determine the capacity of Fh15 to suppress the cytokine storm and prevent the mortality rate of mice exposed to lethal doses of LPS. BALB/c mice were allotted into two experimental groups of 5 animals each, which received an IP injection with 12mg/kg body wt. of LPS from E. coli 0111: B4. One hour after LPS injection one group received a single IP injection with 100 μg Fh15 and the other group received two injections of 100 μg Fh15 two hours apart. Control groups received IP injection with LPS, Fh15 or PBS alone. Animals were monitored for mortality for 72 hrs. Blood samples were collected from all animals at baseline and by the time they were about to die or survived the LPS lethal challenge. As expected, all animals from LPS-control group succumbed between 12 to 24h following the LPS challenge. In contrast, between 40 to 100% of animals that received the Fh15 treatment survived to the LPS challenge. This notable increase in the survival rate was found associated to significant suppression in the production of pro-inflammatory cytokines such as IL-12, TNF-a and IFN-g, which were measured in serum by BioPlex.