TY - JOUR T1 - A Novel Class of Endotoxin Receptor Agonists with Simplified Structure, Toll-Like Receptor 4-Dependent Immunostimulatory Action, and Adjuvant Activity JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 655 LP - 661 DO - 10.1124/jpet.300.2.655 VL - 300 IS - 2 AU - Lynn D. Hawkins AU - Sally T. Ishizaka AU - Pamela McGuinness AU - Huiming Zhang AU - Wendy Gavin AU - Bruce DeCosta AU - Zhaoyang Meng AU - Hu Yang AU - Maureen Mullarkey AU - Donna W. Young AU - Hua Yang AU - Daniel P. Rossignol AU - Anneliese Nault AU - Jeffrey Rose AU - Melinda Przetak AU - Jesse C. Chow AU - Fabian Gusovsky Y1 - 2002/02/01 UR - http://jpet.aspetjournals.org/content/300/2/655.abstract N2 - A series of novel, synthetic compounds containing lipids linked to a phosphate-containing acyclic backbone are shown to have similar biological properties to lipopolysaccharide (LPS). These compounds showed intrinsic agonistic properties when tested for their ability to stimulate tumor necrosis factor-α in human whole blood and interleukin-6 in U373 human glioblastoma cells without added LPS coreceptor CD14. The presence of the LPS antagonist E5564 completely blocked responses, suggesting that the novel compounds and LPS share a common mechanism of cell activation. Stereoselectivity of the molecules was observed in vitro; compounds with anR,R,R,R-configuration were strongly agonistic, whereas compounds with an R,S,S,R-configuration were much weaker in their activity on human whole blood and U373 cells. We also tested the effect of the compounds in cells transfected with the LPS receptor Toll-like receptor 4 (TLR4), with similar results, further supporting a shared mechanism with LPS. This was confirmed in vivo where the agonists failed to elicit cytokine responses in C3H/HeJ mice lacking TLR4 signaling. Because LPS-like molecules enhance immune responses, the compounds were mixed with tetanus toxoid and administered to mice in an immunization protocol to test for adjuvant activity. They enhanced the generation of specific antibodies against tetanus toxoid. Our results indicate that these unique compounds behave as agonists of TLR4, resulting in responses similar to those elicited by LPS. They display adjuvant activity in vivo and may be useful for the development of vaccine therapies. The American Society for Pharmacology and Experimental Therapeutics ER -