Recombinant Fasciola hepatica fatty acid binding protein (Fh15) as a novel anti-inflammatory biotherapeutic in an acute gram-negative non-human primate sepsis model

Due to their phylogenetic proximity to human, non-human primates (NHP) are considered and adequate choice for basic and pre-clinical model of sepsis. Gram-negative bacteria are the primary causative of sepsis. During infection bacteria continuously release the potent toxin lipopolysaccharide (LPS) into the bloodstream, which triggers an uncontrolled systemic inflammatory response leading to death. Our previous research has demonstrated in vitro and in vivo using a mouse model of septic shock that Fh15, a recombinant variant of Fasciola hepatica fatty acid binding protein, acts as an antagonist of TLR4 suppressing the LPS-induced pro-inflammatory storm. The present study aimed to demonstrate that Fh15 suppress the cytokine storm and other inflammatory markers during the early phase of endotoxemia induced in rhesus macaques by i.v. infusion with lethal doses of live E. coli. Fh15 was administered as isotonic infusion 30 min prior to the bacterial infusion. Among the novel findings reported in this communication, I) Fh15 significantly prevents bacteremia, suppressed LPS levels in plasma and the production of C-reactive protein and procalcitonin, which are key signature of inflammation and bacterial infection, respectively, II) notably reduced the production of pro-inflammatory cytokines, and III) increased innate immune cell populations in blood, which suggest a role in promoting a prolonged steady state in rhesus macaques even in the presence of inflammatory stimuli. THis is the first report demonstrating that a F. hepatica-derived molecule possesses potential as anti-inflammatory drug against endotoxemia in an NHP model.