Novel lipid nanoparticle adjuvants vaccine for porcine reproductive and respiratory syndrome (PRRS) using in-vitro macrophage assays

A novel triple adjuvant (TriAdj) platform formulated in various cationic lipid nanoparticles (L-TriAdj) was tested in-vitro for use in porcine reproductive and respiratory syndrome virus (PRRSV) vaccines. Gene expression changes in a RAW 264.7 macrophage cell line were evaluated (compared to media control) after 12-hour stimulation with: (i) TriAdj alone, (ii) lipid formulations alone, (iii) L-TriAdj (lipid:TriAdj ratio of 3:2 or 2:1), and (iv) L-TriAdj + PRRSV antigen. Tested L-TriAdj formulations were comprised of (i) dimethyldioctadecylammonium bromide (DDAB) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) in a 55:45 ratio (abbreviated as DDAB/DOPE), or (ii) DDAB/DOPE with 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), and cholesterol in a 40:30:20:10 ratio (abbreviated as DDAB/DOPE/DSPC/CHOL). Overall design: Cultured RAW264.7 macrophage cells were stimulated for 12 hours with TriAdj, L-TriAdj, lipid carriers alone, inactivated PRRSV and whole vaccines (adjuvant+PRRSV). RNA was isolated and sequenced to evaluate gene expression changes after 12 hour stimulation.