Alcoholic liver disease remains a major worldwide health problem. This project will continue studies designed to investigate the hypothesis that metabolically derived aldehydes complex with liver cell proteins forming stable aldehyde adducts that may act as antigens to induce immune responses and play a role in alcohol related liver damage. Recent studies have shown that acetaldehyde and the lipid peroxidation-derived aldehyde, malondialdehyde, can react together with proteins in a synergistic manner to form distinct hybrid adducts which have been designated as MAA adducts. MAA adducts have been found in the livers of ethanol-fed rats and are immunogenic with the production of highly specific antibodies in the absence of adjuvants. Additionally, dependent upon the immunizing protein modified, the antibodies can be either to MAA or to the unmodified protein. Experimental models have demonstrated that antibodies to both self and non-self proteins can be generated following adduct modification. Therefore, it is suggested that proteins are modified with MAA as a result of chronic ethanol consumption and thereby induce an unique immune response to the MAA-epitope, as well as to nonmodified epitopes on soluble carrier proteins. The ability of MAA-modified soluble proteins to induce immune responses is dependent on the unique features of antigen processing andpresentation, and mechanisms of B- and T-cell immunoregulation. The mechanisms of MAA-induced protein immune responses will be addressed by the following specific aims: 1) Characterize the ability of soluble MAA-adducted non-self (HEL, OVA) and self (MSA) proteins to induce antibody responses in the absence of adjuvant to the MAA epitopes or to unmodified carrier protein epitopes; 2) Determine the T cell proliferative responses to MAA adducted non-self and self soluble proteins following immunization in the absence of adjuvants; 3) Determine the cell types that are involved in the uptake, processing, and presentation of MAA-adducted non-self and self proteins 4) Using an in vitro model of Class I antigen presentation, assess the ability of MAA adducted proteins to induce cytotoxic T cell responses to non-self and self-antigens 5) Identify self liver proteins modified with MAA; Determine the effects of chronic ethanol consumption on each of these processes. Using the assays defined above, assess the in vivo role of MAA in initiating these responses in the presence and absence of chronic ethanol consumption. Overall, these studies will begin to develop the mechanisms by which MAA-modified proteins in the presence or absence of alcohol may induce antibody and T cell responses in the absence of adjuvants. Additionally, they should develop the techniques necessary to assess how endogenous MAA-proteins influence the immune system.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37AA007818-16
Application #
7236743
Study Section
Special Emphasis Panel (NSS)
Program Officer
Jung, Kathy
Project Start
1989-04-01
Project End
2009-05-31
Budget Start
2007-06-01
Budget End
2008-05-31
Support Year
16
Fiscal Year
2007
Total Cost
$265,090
Indirect Cost
Name
University of Nebraska Medical Center
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
168559177
City
Omaha
State
NE
Country
United States
Zip Code
68198
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Thiele, Geoffrey M; Duryee, Michael J; Willis, Monte S et al. (2010) Autoimmune hepatitis induced by syngeneic liver cytosolic proteins biotransformed by alcohol metabolites. Alcohol Clin Exp Res 34:2126-36
Duryee, Michael J; Klassen, Lynell W; Schaffert, Courtney S et al. (2010) Malondialdehyde-acetaldehyde adduct is the dominant epitope after MDA modification of proteins in atherosclerosis. Free Radic Biol Med 49:1480-6
Schaffert, Courtney S; Duryee, Michael J; Bennett, Robert G et al. (2010) Exposure of precision-cut rat liver slices to ethanol accelerates fibrogenesis. Am J Physiol Gastrointest Liver Physiol 299:G661-8
Klassen, Lynell W; Thiele, Geoffrey M; Duryee, Michael J et al. (2008) An in vitro method of alcoholic liver injury using precision-cut liver slices from rats. Biochem Pharmacol 76:426-36
Duryee, Michael J; Klassen, Lynell W; Jones, Bonnie L et al. (2008) Increased immunogenicity to P815 cells modified with malondialdehyde and acetaldehyde. Int Immunopharmacol 8:1112-8
Freeman, Thomas L; Haver, Alvin; Duryee, Michael J et al. (2005) Aldehydes in cigarette smoke react with the lipid peroxidation product malonaldehyde to form fluorescent protein adducts on lysines. Chem Res Toxicol 18:817-24
Thiele, Geoffrey M; Duryee, Michael J; Freeman, Thomas L et al. (2005) Rat sinusoidal liver endothelial cells (SECs) produce pro-fibrotic factors in response to adducts formed from the metabolites of ethanol. Biochem Pharmacol 70:1593-600
Xu, D; Thiele, G M; Beckenhauer, J L et al. (1998) Detection of circulating antibodies to malondialdehyde-acetaldehyde adducts in ethanol-fed rats. Gastroenterology 115:686-92
Xu, D; Thiele, G M; Kearley, M L et al. (1997) Epitope characterization of malondialdehyde-acetaldehyde adducts using an enzyme-linked immunosorbent assay. Chem Res Toxicol 10:978-86

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