ENDOTOXIN-INDUCED EXPRESSION OF ENDOTOXIN BINDING-SITES ON MURINE BONE-MARROW CELLS

A variety of binding sites for endotoxin (LPS) have been identified on leukocytes. However, the sequence of expression of these receptors, a nd their interrelations, are poorly understood. In this report, we sho w that in LPS-responsive hosts, interaction of nanomolar concentration s of LPS with bone marrow cells induces the expression of new specific LPS-binding sites. Cells from LPS-nonresponsive (C3H/HeJ) mice do not express these receptors after LPS treatment. Experimental differences in the conditions allowing the induction and the detection of these b inding sites (influence of Leishmania lipophosphoglycan, role of serum ), support the hypothesis that interaction of LPS with primary recepto rs on bone marrow cells triggers the expression of secondary LPS recep tors, and that the two types of receptors have distinct fine specifici ties.