Recombinant human plasma phospholipid transfer protein (PLTP) to prevent bacterial growth and to treat sepsis

Valérie Deckert,Véronique Turquois,Stéphanie Lemaire,Franck Ménétrier,Jérôme Labbé,Caroline Chabert-Le Borgne,Nicolas Desroche,Jean‐Paul Pais De Barros ,Naïg Le Guern ,Thomas Gautier,Delphine Larose,Catherine Desrumaux,L Lebrun ,Louis‐Marie Houdebiné ,Pierre-Jean Ripoll,David Masson,Guillaume Maquart,Jacques Grober,Charles W Thomas ,Laurent Lagrost

doi:10.1038/s41598-017-03285-9

Abstract

Although plasma phospholipid transfer protein (PLTP) has been mainly studied in the context of atherosclerosis, it shares homology with proteins involved in innate immunity. Here, we produced active recombinant human PLTP (rhPLTP) in the milk of new lines of transgenic rabbits. We successfully used rhPLTP as an exogenous therapeutic protein to treat endotoxemia and sepsis. In mouse models with injections of purified lipopolysaccharides or with polymicrobial infection, we demonstrated that rhPLTP prevented bacterial growth and detoxified LPS. In further support of the antimicrobial effect of PLTP, PLTP-knocked out mice were found to be less able than wild-type mice to fight against sepsis. To our knowledge, the production of rhPLTP to counter infection and to reduce endotoxemia and its harmful consequences is reported here for the first time. This paves the way for a novel strategy to satisfy long-felt, but unmet needs to prevent and treat sepsis.

Highlights

Plasma phospholipid transfer protein (PLTP) is ubiquitously expressed in vertebrate species
We generated a new model of transgenic rabbit in which an optimized sequence corresponding to human PLTP cDNA was placed under the control of the rabbit whey acidic protein (WAP) promoter (HuPLTPTg rabbits) (Fig. 1A)
The anti-microbial properties could be highly conserved in a preparation of recombinant human PLTP, which was obtained from the mammary gland of a new line of PLTP transgenic rabbits, which were used as a bioreactor

Summary

Introduction

Plasma phospholipid transfer protein (PLTP) is ubiquitously expressed in vertebrate species. In further support of the pathophysiological relevance of the PLTP-mediated detoxification of LPS, PLTP-knocked out mice were less able than wild-type mice with naturally elevated PLTP expression to get rid of purified LPS6. This suggests that recombinant PLTP might constitute a novel and relevant therapeutic tool for the prevention and treatment of LPS-mediated inflammation. There is, a potential drawback due to putative sequestration of the recombinant protein in milk fat globules At this stage, it is unknown whether the production of recombinant human PLTP (rhPLTP) in transgenic rabbit milk is a safe and promising strategy to generate large amounts of PLTP for therapeutic purposes. In further support of the antimicrobial effect of PLTP, PLTP-knocked out mice were found to be less able than wild-type (WT) mice to fight against sepsis

Methods

Results

Conclusion