Restoration of lipopolysaccharide-mediated B-cell response after expression of a cDNA encoding a GTP-binding protein

Previous analysis of hybrid progeny derived from lipopolysaccharide (LPS) responder and nonresponder inbred mouse strains demonstrated that a single genetic locus controlled responsiveness to LPS. Using a differential functional screening approach, we report the isolation of a cDNA that has sequence homology to a GTP-binding protein. Expression of the cDNA in splenic B cells of C3H/HeJ nonresponder, endotoxin-resistant mice resulted in polyclonal B-cell activation in response to LPS stimulation. Thus a GTP-binding protein may be involved in LPS stimulation in B cells and perhaps other cell types.