Recent studies from this laboratory have shown that experimental injury causes a depression of the ability of hepatic macrophage complement receptors to bind erythrocytes coated with antibodies and complement. It was also shown that the depression of complement receptor function in uninjured animals was associated with increased susceptibility to infection. These findings suggest that hepatic macrophage receptor function may play an important role in mediating the depression of host defense associated with injury.
The aims of this proposal are: (1) to determine hepatic macrophage Fc receptor function. Fc receptor function will be studied because both complement and antibodies are important for the clearance and phagocytosis of bacteria. Fc receptor clearance function will be determined from the clearance of aggregated IgG and Fc receptor phagocytic function will be determined using electron microscopy. The effect of injury on hepatic Fc receptor function and the effect of Fc receptor depression on host defense will be determine, (2) to study the mechanism of the depression of hepatic complement and Fc receptor clearance function. Receptor function will be depressed by the injection of particulates. The role of the depletion of these receptors from the macrophage surface will be determined, (3) to study the mechanism of the increased susceptibility to infection associated with depressed hepatic complement and Fc receptor function. The importance of the composition of the particulate material used to depress receptor function and the role of depressed bacterial clearance, bacterial phagocytosis and bacterial killing will be determined. Another aspect of this study is to determine the degree to which the evaluation of receptor function gives an indication of host defense status. The long-range objective of this study is to elucidate the mechanism of impaired host defense in severely injured patients and thereby to provide a basis for improved diagnosis and treatment of these patients. This multidisciplinary study involves the areas of physiology, immunology, biochemistry, bacteriology, and histology represents a new approach to the mechanism of impaired host defense in severely injured patients.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM026102-07
Application #
3273571
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Project Start
1978-12-01
Project End
1988-07-31
Budget Start
1985-08-31
Budget End
1986-07-31
Support Year
7
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Albany Medical College
Department
Type
Schools of Medicine
DUNS #
City
Albany
State
NY
Country
United States
Zip Code
12208
Schwacha, M G; Gudewicz, P W; Snyder, J A et al. (1993) Depression of macrophage respiratory burst capacity and arachidonic acid release after Fc receptor-mediated phagocytosis. J Immunol 150:236-45
Schwacha, M G; Loegering, D J (1992) Respiratory burst capacity of activated macrophages is resistant to depression by erythrocyte phagocytosis. Inflammation 16:285-94
Schwacha, M G; Loegering, D J (1992) Corynebacterium parvum can reverse the depression of macrophage hydrogen peroxide production caused by erythrocyte phagocytosis. Immunol Invest 21:231-9
Schwacha, M G; Loegering, D J; Commins, L M et al. (1991) Scavengers of reactive oxygen intermediates do not mediate the depression of macrophage hydrogen peroxide production caused by erythrocyte phagocytosis. Inflammation 15:447-56
Loegering, D J; Schwacha, M G (1991) Macrophage hydrogen peroxide production and phagocytic function are decreased following phagocytosis mediated by Fc receptors but not complement receptors. Biochem Biophys Res Commun 180:268-72
Commins, L M; Loegering, D J; Gudewicz, P W (1990) Effect of phagocytosis of erythrocytes and erythrocyte ghosts on macrophage phagocytic function and hydrogen peroxide production. Inflammation 14:705-16
Loegering, D J; Blumenstock, F A; Cuddy, B G (1989) Determination of Kupffer cell Fc receptor function in vivo following injury. Proc Soc Exp Biol Med 192:255-60
Commins, L M; Loegering, D J; Minnear, F L (1989) Effect of ibuprofen and dexamethasone on Kupffer cell complement receptor function after endotoxemia and the phagocytosis of erythrocytes. Circ Shock 27:237-44
Loegering, D J; Commins, L M (1988) Effect of beta-receptor stimulation on Kupffer cell complement receptor clearance function. Circ Shock 25:325-32
Loegering, D J; Kaplan, J E; Vincent, P A et al. (1988) Kupffer cell complement receptor clearance function after surgical injury and phagocytosis of immune complexes: effect of changes in plasma fibronectin. J Lab Clin Med 111:504-10

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