The long-term objective of this research project is to obtain experimental information that will lead to a thorough understanding of the role of antibody/dsDNA immune complexes in the pathogenesis of systemic lupus erythematous (SLE). Several lines of evidence indicate that the potential of immune complexes to be safely cleared from the circulation may depend upon their ability to fix complement and be recognized by the C3b/C4b receptors of human red blood cells. More recent evidence suggests that a similar mechanism may operate in non-primates, but in this case the relevant receptors are apparently on the animals' platelets, rather than red blood cells. In vivo studies on baboons, guinea pigs and rabbits will therefore focus on how the physical properties of the antibody/dsDNA immune complexes and the complement activity and C3b/C4b receptor activity of the animals affect the clearance of these immune complexes from the circulation. Specifically, we intend to do the following: (1) Investigate the rate of clearance of radiolabeled antibody/DNA immune complexes of different sizes from the circulation of these animals. (2) Determine the organ distribution of the complexes after they leave the circulation. (3) Examine how compromising the complement system of the animals influences the immune complex clearance rates and organ distribution. (4) Perform in vitro studies to quantitate C3 fragments and antibody/dsDNA stoichiometries on these complexes and correlate these results with the in vivo findings. These studies will be conducted on immune complexes prepared with both dsDNA and ss DNA molecules in a wide range of molecular weights. Principal techniques to be used include radioimmunoassays, centrifugation, and a variety of methods that focus on complement technology. Information gained from the successful completion of the proposed research will add to our knowledge of immune complex diseases and should help in the design of specific therapeutic modalities for such diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR024083-11
Application #
3155269
Study Section
General Medicine A Subcommittee 2 (GMA)
Project Start
1979-09-30
Project End
1992-03-31
Budget Start
1990-04-01
Budget End
1992-03-31
Support Year
11
Fiscal Year
1990
Total Cost
Indirect Cost
Name
University of Virginia
Department
Type
Schools of Medicine
DUNS #
001910777
City
Charlottesville
State
VA
Country
United States
Zip Code
22904
Taylor, R P; Pocanic, F; Reist, C et al. (1991) Complement-opsonized IgG antibody/dsDNA immune complexes bind to CR1 clusters on isolated human erythrocytes. Clin Immunol Immunopathol 61:143-60
Lutz, H U; Stammler, P; Kock, D et al. (1991) Opsonic potential of C3b-anti-band 3 complexes when generated on senescent and oxidatively stressed red cells or in fluid phase. Adv Exp Med Biol 307:367-76
Taylor, R P; Sutherland, W M; Reist, C J et al. (1991) Use of heteropolymeric monoclonal antibodies to attach antigens to the C3b receptor of human erythrocytes: a potential therapeutic treatment. Proc Natl Acad Sci U S A 88:3305-9
Taylor, R P (1990) [The biophysical chemistry of complement-fixing DNA-anti-DNA immune complexes] Ter Arkh 62:27-32
Edberg, J C; Tosic, L; Taylor, R P (1989) Immune adherence and the processing of soluble complement-fixing antibody/DNA immune complexes in mice. Clin Immunol Immunopathol 51:118-32
Taylor, R P; Wright, E L; Pocanic, F (1989) Quantitative analyses of C3b capture and immune adherence of IgM antibody/dsDNA immune complexes. J Immunol 143:3626-31
Kimberly, R P; Edberg, J C; Merriam, L T et al. (1989) In vivo handling of soluble complement fixing Ab/dsDNA immune complexes in chimpanzees. J Clin Invest 84:962-70
Tosic, L; Sutherland, W M; Kurek, J et al. (1989) Preparation of monoclonal antibodies to C3b by immunization with C3b(i)-sepharose. J Immunol Methods 120:241-9
Schifferli, J A; Taylor, R P (1989) Physiological and pathological aspects of circulating immune complexes. Kidney Int 35:993-1003
Edberg, J C; Tosic, L; Wright, E L et al. (1988) Quantitative analyses of the relationship between C3 consumption, C3b capture, and immune adherence of complement-fixing antibody/DNA immune complexes. J Immunol 141:4258-65