In vitro evaluation of the immunostimulatory effects of PAM2CS lipopeptide-based TLR2 agonists in chicken peripheral...

Although toll like receptor (TLR) ligands are effective vaccine adjuvants, current synthetic TLR2 agonists suffer from low solubility, high cost, and detrimental effect towards protein antigen. Present study aimed to evaluate the immunostimulatory potential of five in-house PAM2CS lipopeptide-based TLR2 agonists (P1, P2, P6, P7 and P8) using peripheral blood mononuclear cells (PBMCs) from chicken (n = 4). Each agonist (10 µg/mL) significantly upregulated the expression of interleukin (IL)-1 β and inducible nitric oxide synthase (iNOS) at 3 h post-treatment with highest expression of IL-1β mRNA was observed with P1. There was a significant up-regulation of interferon (IFN)-β and IFN-γ by treatment with P1 at 3 and 12 h intervals (p < 0.05). Further, IL-4 mRNA was significantly upregulated with P1 and P7 treatment at 12 and 24 h post-treatment respectively. Our results demonstrate that among all five agonists, P1 was the most effective in enhancing immune response genes expression including both type I and type II interferons, and in eliciting a balanced Th1 and Th2 responses.