Endotoxic-lipopolysaccharide-specific binding proteins on lymphoid cells of various animal species: association with endotoxin susceptibility.

Endotoxic lipopolysaccharide (LPS), a common structural component of all gram-negative bacteria, is well recognized for its capacity to interact with and perturb immunologically relevant cells. Using a radioiodinated, photoactivatable LPS probe, we have recently identified an 80-kilodalton LPS-specific binding protein on murine B lymphocytes. We now have extended these studies to determine if other mammalian species, as well as representative endotoxin-resistant species (frog and chicken), have a similar LPS-binding protein. We have identified what appears to be a relatively conserved 80-kilodalton LPS-binding protein on mononuclear cells of all mammalian species tested. However, both frog and chicken leukocytes failed to show the presence of a similar LPS-binding protein. It is possible that the presence of specific LPS-binding proteins may be important for endotoxin sensitivity of most mammalian species.