Fasciola hepatica Glutathione S-tranferase suppresses inflammatory cytokines and chemokines in vivo against lethal doses of lipopolysaccharide on C57Bl/6 mice.

Abstract

Abstract The world-wide helminth parasite, Fasciola hepatica, is an excellent immunomodulator. It survives in the host by preventing immune responses against itself by using excretory-secretory products (ESPs). One of the ESPs well-known for its anti-oxidant properties is Glutathione S-transferase (GST). Although it has been studied as a vaccine, the function GST plays in immunomodulation has scarcely been studied. Previously, we reported how the use of GST prior to TLR ligands significantly decreased TLR activation in vitro and boosted the survival rate of mice injected intraperitoneally with GST before a lethal dose of LPS by 80%. In this study, we investigate whether these C57BL/6 mice that survived after a lethal dose of LPS experienced a reduction in inflammatory cytokines and/or chemokines. For this, C57BL/6 6–8 week-old mice were allotted into two groups of 12 animals each. The control group (n=12) was injected intraperitoneally with 0.1M endotoxin free PBS and allowed to rest 1 hr, while the experimental group (n=12) was injected intraperitoneally with 15 ug of GST and allowed to rest 1 hour. Afterwards, both groups were injected with a lethal dose (1 mg) of E.coli LPS (serotype 0111:B4; Sigma) and monitored during a 48 hour period. Sera from mice in the experimental group were compared to the control group by using a Cytokine 20-Plex Mouse Panel kit (Invitrogen) for a wide array of cytokines and chemokines. Our results demonstrate that injecting 15ug of GST intraperitoneally 1 hour before a lethal dose of LPS gives the surviving 80% of C57BL/6 mice significantly reduced amounts of pro-inflammatory cytokines and chemokines, such as IL-1β (p = 0.0004), IL-12p70 (p = 0.0001) and MIP-1α (p = 0.0024), after 48 hrs.