C EBP-RELATED PROTEIN-2 CONFERS LIPOPOLYSACCHARIDE-INDUCIBLE EXPRESSION OF INTERLEUKIN-6 AND MONOCYTE CHEMOATTRACTANT PROTEIN-1 TO A LYMPHOBLASTIC CELL-LINE/

C/EBP-related proteins 2 and 3 (CRP2 and CRP3) are differentially expr essed by P388 lymphoblasts and their derivative P388D1(IL1) macrophage s. We have ectopically expressed CRP2, the predominant CRP in macropha ges, in P388 lymphoblasts. The expression of CRP2 is sufficient to con fer the lipopolysaccharide (LPS)-inducible expression of interleukin 6 and monocyte chemoattractant protein 1 to lymphoblasts, which normall y do not display LPS induction of inflammatory cytokines. Consistent w ith these findings, the expression of CRP2 antisense RNA blocks the LP S induction of IL-6 expression in P388D1(IL1) macrophages. This work c learly establishes the essential role of CRP2 in the induction of cyto kine genes by LPS. Additionally, these data add MCP-1 to the list of c ytokines showing an involvement of CRP2 in their expression.