LIPOPOLYSACCHARIDE REGULATES CYSTEINE-RICH INTESTINAL PROTEIN, A ZINC-FINGER PROTEIN, IN IMMUNE CELLS AND PLASMA

Cysteine-rich intestinal protein (GRIP), a double zinc-finger LIM prot ein, is expressed in great abundance in the intestine, We have found c omparable levels of GRIP mRNA in peritoneal macrophages, peripheral bl ood mononuclear cells (PBMC), and lesser amounts hi thymus and spleen, Because GRIP expression was high in immune cells, rats were challenge d with lipopolysaccharide (LPS) to determine whether expression tvas a ltered during the acute-phase immune response, Immunocytochemistry sho wed that, in adherent mononuclear cells, GRIP protein was localized in the cytoplasm. CRIP mRNA levels increased over time after LPS injecti on in peritoneal macrophages, PBMC, spleen, and intestine. No changes hi GRIP mRNA level were seen in either liver or thymus, In PBMC, the l evel of GRIP mRNA decreased before increasing later in the acute-phase immune response, GRIP protein was found in the plasma, Shortly after LPS administration plasma GRIP decreased, suggesting that GRIP Tvas ei ther passively diffused out of capillaries or was actively shunted int o tissues to execute its function, Increased GRIP expression seen in r esponse to LPS suggests that GRIP may play a role in immune cell activ ation or differentiation or in processes associated with cellular repa ir.