Current methods for in vivo thrombus detection either lack specificity or pose additional health risks. With the tools of molecular immunology and syntheitic peptide chemistry, we plan to prepare a clinically useful, diagnostic antibody that possesses specificity for human fibrin (the structural protein in thrombi) and provides sufficient sensitivity for in vivo thrombus detection by gamma scintigraphy. Our strategy will emphasize the differences between fibrin and its soluble precursor, fibrinogen, and will focus on ways to select fibrinspecific antibodies. Synthetic peptides will be designed to mimic fibrinunique epitopes and used to elicit antibodies that will bind human fibrin in the presence of fibrinogen. This approach was validated during the previous grant period when we used a synthetic peptide corresponding to the N terminus of the human fibrin beta-chain to elicit monoclonal antibodies that bound to fibrin monomer in the presence of fibrinogen. The in vivo specificity of one monoclonal antibody (64C5) was confirmed in experiments using chicken, rabbit and dog models. In the research proposed here, we focus on the design and testing of various fibrin-like peptides corresponding to thrombin cleavage sites and Factor XIIIa cross-link sites, and describe plans for an improved screening strategy that uses fibrin miniclots rather than fibrin monomers as antigens.
Our specific aims i nclude the in vivo testing of antibody 5D7 as a gamma scintigraphic agent for detecting experimental thrombi; the preparation of monoclonal antibodies that avidly bind to clotted fibrin; the synthesis and refinement of cross-link antigens related to gamma-chain cross-link sites; and the structural and immunochemical study of the alpha-chain cross-link site in order to identify a new fibrin-unique epitope. Three specific benefits will result from these experiments: First, they will provide a detailed immunochemical analysis of unique epitopes on the fibrin molecule. They will also suggest general methods for differentiating any protein from its precursor. Second, they will provide reagents that can tag thrombi in vivo. Third, they will lay the foundation upon which a sensitive and specific noninvasive test for life-threatening thromboembolism can be built.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
7R01HL028015-09
Application #
3339435
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1990-01-01
Project End
1992-12-31
Budget Start
1990-01-01
Budget End
1990-12-31
Support Year
9
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Princeton University
Department
Type
Schools of Arts and Sciences
DUNS #
002484665
City
Princeton
State
NJ
Country
United States
Zip Code
08544
Liu, Q; Matsueda, G; Brown, E et al. (1997) The AGDV residues on the gamma chain carboxyl terminus of platelet-bound fibrinogen are needed for platelet aggregation. Biochim Biophys Acta 1343:316-26
Taubenfeld, S M; Song, Y; Sheng, D et al. (1995) A monoclonal antibody against a peptide sequence of fibrinogen gamma chain acts as an inhibitor of factor XIII-mediated crosslinking of human fibrin. Thromb Haemost 74:923-7
Song, Y C; Sheng, D; Taubenfeld, S M et al. (1994) A microtiter assay for factor XIII using fibrinogen and biotinylcadaverine as substrates. Anal Biochem 223:88-92
Song, Y; Taubenfeld, S M; Sheng, D et al. (1994) Characterization of a monoclonal antibody directed against the carboxyl-terminus of human factor XIII. An epitope exposed upon denaturation and conserved across species lines. Thromb Haemost 71:62-7
Gartner, T K; Amrani, D L; Derrick, J M (1994) Characterization of adhesion of non-exogenously stimulated and resting platelets in normal plasma to fibrinogen and its fragments. Blood Coagul Fibrinolysis 5:747-54
Ju, S T; Nonogaki, T; Bernatowicz, M S et al. (1993) The B cell immune response to an idiotype-inducing peptide epitope can be inhibited by immunodominance of a neighboring epitope. J Immunol 150:2641-7
Gartner, T K; Amrani, D L; Derrick, J M et al. (1993) Characterization of adhesion of ""resting"" and stimulated platelets to fibrinogen and its fragments. Thromb Res 71:47-60
Blumenstein, M; Matsueda, G R; Timmons, S et al. (1992) A beta-turn is present in the 392-411 segment of the human fibrinogen gamma-chain. Effects of structural changes in this segment on affinity to antibody 4A5. Biochemistry 31:10692-8
Reed, G L; Matsueda, G R; Haber, E (1992) Platelet factor XIII increases the fibrinolytic resistance of platelet-rich clots by accelerating the crosslinking of alpha 2-antiplasmin to fibrin. Thromb Haemost 68:315-20
Chen, F; Haber, E; Matsueda, G R (1992) Availability of the B beta(15-21) epitope on cross-linked human fibrin and its plasmic degradation products. Thromb Haemost 67:335-40

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