Inhibition of lipopolysaccharide mitogenicity with characterized anti-lipid A monoclonal antibodies

Antibodies to lipid A were raised in mice immunized with non-hydrolysed Bordetella pertussis microorganisms, coated with lipid A isolated from the same bacteria. Anti-lipid A activity of immune sera was measured by radioimmunoassay. Four hybrid cell lines that secrete antibodies directed against the hydrophobic region of B. pertussis lipopolysaccharide were produced by cell fusion between myeloma cells and spleen cells from immunized C3H/He-PAS mice. Differences were observed in the potency of the isolated monoclonal antibodies to inhibit B cell proliferation induced by lipopolysaccharide (LPS) or by lipid A, suggesting a selective recognition of effector sites present on the hydrophobic region of LPS.