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

Abstract Due to their phylogenetic proximity to human, non-human primates are considered an 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 the Fasciola hepatica fatty acid binding protein, acts as an antagonist of TLR4 suppressing the LPS-induced pro-inflammatory cytokine storm. The present communication is a proof-of concept study aimed to demonstrate that a low-dose of Fh15 suppresses the cytokine storm and other inflammatory markers during the early phase of sepsis induced in rhesus macaques by i.v. infusion with lethal doses of live E. coli. Fh15 was administrated as isotonic infusion 30 min prior to the bacterial infusion. Among the novel findings reported in this communication, I) Fh15 significantly prevented 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) 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 sepsis in an NHP-model. This research was supported by the National Institute of Allergy and Infectious Diseases Grant/Award Number: 1SC1AI155439-01, Office of Research Infrastructure Program of NIH (ORIP-NIH) 2016-2021, Grant/Award Number: P40OD12271; National Institute on Minorities Health and Health Disparities, Grant/Award Number: 5R25GM061151, G12MD007600 and R25GM061838.