The overall objective of this proposal is to elucidate the role of inflammatory neutrophils and activated Kupffer and endothelial cells on the induction of hepatotoxicity in chronic alcoholics, with a view to developing immunotherapeutic and biotechnological methods for the treatment of tissue injury after prolonged alcohol consumption. This proposal is based on the hypothesis that chronic alcohol intoxication regulates the expression of adhesion molecules and leukocyte infiltration into the liver. Such event may also be mediated by the release of chemotractant factors released by hepatocytes, Kupffer and endothelial cells after exposure to ethanol. As a consequence, a wide spectrum of bioactive substances are released that may contribute to the initiation of hepatic injury in susceptible individuals. It is also hypothesized that such events may be exacerbated by endotoxin.
Specific aim I will investigate the expression of adhesion molecules, i.e., Beta2-integrins and selectins on neutrophils and their counterreceptors on Kupffer, endothelial cells and hepatocytes. These molecules are important for the sequestration of inflammatory neutrophils into the liver after an alcohol insult.
Specific aim 2 will examine the formation of oxygen-derived radicals, cytolytic proteases, proinflammatory cytokines and chemokines in the liver, which are considered to contribute to the induction of tissue injury in chronic alcoholics. Based on the results of specific aims 1 & 2, specific aim 3 examines the hypothesis that by neutralizing the deleterious effects of these metabolites and their sources (e. g. neutrophils and macrophages), hepatic injury will be attenuated or inhibited. This will be achieved by using free radical scavengers, protease inhibitors, monoclonal antibodies against adhesion molecules and liposome encapsulated dichloromethylene diphosphonate (which specifically targets Kupffer cells). This proposal is unique and novel, because it will use modern immunological and biotechnological approaches for the treatment of liver disease in chronic alcoholics. The use of free radical scavengers, liposomes and monoclonal antibodies in the immunotherapy of endotoxemia, cancer, ischemia-reperfusion and immunosuppression is gaining acceptance, and may also be applied to the treatment of tissue injury in the liver and other organs during chronic alcohol intoxication.
Bautista, A P (2000) Impact of alcohol on the ability of Kupffer cells to produce chemokines and its role in alcoholic liver disease. J Gastroenterol Hepatol 15:349-56 |
Bautista, A P; Spitzer, J J (1999) Role of Kupffer cells in the ethanol-induced oxidative stress in the liver. Front Biosci 4:D589-95 |
Bautista, A P (1998) The role of Kupffer cells and reactive oxygen species in hepatic injury during acute and chronic alcohol intoxication. Alcohol Clin Exp Res 22:255S-259S |
Bautista, A P (1997) Chronic alcohol intoxication induces hepatic injury through enhanced macrophage inflammatory protein-2 production and intercellular adhesion molecule-1 expression in the liver. Hepatology 25:335-42 |
Bautista, A P; Spitzer, J J (1996) Cross-tolerance between acute alcohol intoxication and endotoxemia. Alcohol Clin Exp Res 20:1395-400 |