LISTERIA-MONOCYTOGENES INFECTION INCREASES NEUTROPHIL ADHESION AND DAMAGE TO A MURINE HEPATOCYTE CELL-LINE IN-VITRO

Several studies have reported that Listeria monocytogenes multiplies within hepatocytes and that inflammatory neutrophils inhibit this intracellular growth in vivo. In the present study, we used a murine embryonic hepatocyte cell line (ATCC TIB73) as an in vitro model to investigate neutrophil-hepatocyte interactions. Murine peritoneal exudate neutrophils adhered more readily to L. monocytogenes-infected hepatocyte monolayers than to uninfected monolayers or monolayers infected with actA(-) and hly(-) mutants of L. monocytogenes. L. monocytogenes-infected TIB73 cells increased their surface expression of ICAM-1 as compared with uninfected TIB73 cells. Neutrophil adherence and oxidative stress to TIB73 cells were reduced by pre-incubating the hepatocyte monolayers with anti-ICAM-1 monoclonal antibody and diminished further by pre-incubating the peritoneal exudate neutrophils with an anti-CR3 monoclonal antibody.