Innate immune agonists conjugated to nanolipoproteins elicit robust inflammatory responses in mouse macrophages: implications for host-based therapeutics.

Abstract Modulation of the innate immune system has the potential to provide transient, non-specific protection from a variety of infectious organisms. We hypothesize that combinatorial formulations of synthetic innate immune agonists may significantly enhance protection over single-agonist formulations. To readily incorporate multiple, chemically diverse agonists onto a single particulate platform for co-localized delivery, nanolipoprotein particles (NLPs) will be used. NLPs are discoidal, nanometer-sized particles comprised of self-assembled phospholipid membranes and apolipoproteins, analogous to reconstituted HDLs. NLPs assembled with human apolipoproteins have been used for numerous biotechnology applications, including membrane protein solubilization, drug delivery, and diagnostic imaging. NLPs can be functionalized to incorporate myriad agonists, including CpG-containing oligonucleotides, monophosphoryl Lipid A, muramyl dipeptide, flagellin, and an LL-37 analog. Development of NLPs incorporating CpGs and MPLA will be described, as well as preliminary results from in vitro analyses, including quantitative inflammatory cytokine secretion, cellular cytotoxicity, and cellular localization. Our data indicate that agonist:NLP constructs are internalized by macrophages, are immunostimulatory, and induce low levels of cellular cytotoxicity.