ABSTRACT
The innate immune system is an ancient evolutionary response by multicellular organisms to infectious pathogens. The receptors that activate the innate immune response must recognize a broad variety of “coats of arms” heralding attack. The molecules accomplishing this function have been dubbed pattern recognition receptors by Janeway because they have evolved not to recognize any one pathogen with exquisite sensitivity but to recognize families of pathogens by virtue of the pathogen’s conserved patterns of structure. In terms of defining the functional properties of lipopolysaccharide (LPS) binding protein (LBP), many assays have proven useful. Opsonization by LBP has been demonstrated by counting binding of LPS-coated particles to cells or by measuring cell-associated, fiuoresceinated gram-negative bacteria. In addition to transferring LPS to lipoproteins, Wurfel et al. observed that LBP in plasma appeared to be bound directly to plasma lipoprotein.
