Recombinant adenovirus vector bearing antisense macrophage migration inhibitory factor cDNA prevents acute lipopolysaccharide-induced liver failure in mice

Abstract

Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine involved in delayed hypersensitivity and cellular immunity. MIF also acts as a proinflammatory cytokine and counterregulates the anti-inflammatory effects of glucocorticoids. Exogenous gene transfer mediated by adenovirus is useful to study a particular molecular function as well as to develop gene therapy strategies. A recombinant adenovirus containing sense and antisense murine MIF (mMIF) cDNA inserts was constructed using a cosmid-terminal protein complex method. The sense mMIF adenovirus (AxCA-mMIFS) efficiently induced mMIF in COS-7 cells that endogenously lack mMIF in a dose-dependent manner. In contrast, the antisense mMIF adenovirus (AxCA-mMIFAS) inhibited the expression of mMIF in NIH3T3 cells in a dose-dependent manner. To assess the pathophysiologic role of MIF in acute liver failure, we induced acute onset of liver damage in mice (male JcI:ICR) by a combined treatment of Bacille Calmette-Guerin (BCG) and lipopolysaccharide (LPS). mMIF level in the liver of mice infected with AxCA-mMIFAS showed a significant reduction in MIF production in response to BCG-LPS compared with mice treated without viral infection and with AxCA-mMIFS. In addition, the immunohistochemical staining demonstrated that F4/80 antigen on macrophage was enhanced in liver infected with AxCA-mMIFS but reduced in liver infected with AxCA-mMIFAS. The staining intensity is correlated with the mMIF antigen level in liver tissue. The survival rate of mice infected with AxCA-mMIFAS was significantly higher than that of mice treated with PBS and infected with AxCA-LacZ in BCG-LPS. These results suggest that inhibition of MIF production, using recombinant adenovirus bearing the antisense MIF gene, reduced the mortality rate in BCG-LPS-induced liver failure in mice. This finding might aid in the further development of gene therapy targeting MIF.