Jiang ZF, Georgel P, Du X, Shamel L, Sovath S, Mudd S, Huber M, Kalis C, Keck S, Galanos C, Freudenberg M, Beutler B*, CD14 is required for MyD88-independent LPS signaling, NATURE IMMUNOLOGY, 6(6), 565-70. 2005.

Abstract The recessive mutation 'Heedless' (hdl) was detected in third-generation N-ethyl-N-nitrosourea-mutated mice that showed defective responses to microbial inducers. Macrophages from Heedless homozygotes signaled by the MyD88-dependent pathway in response to rough lipopolysaccharide (LPS) and lipid A, but not in response to smooth LPS. In addition, the Heedless mutation prevented TRAM-TRIF-dependent signaling in response to all LPS chemotypes. Heedless also abolished macrophage responses to vesicular stomatitis virus and substantially inhibited responses to specific ligands for the Toll-like receptor 2 (TLR2)-TLR6 heterodimer. The Heedless phenotype was positionally ascribed to a premature stop codon in Cd14. Our data suggest that the TLR4-MD-2 complex distinguishes LPS chemotypes, ......