Two areas of research both related to killing of human tumor cells by monoclonal antibody and complement are proposed in this grant application. One area concentrates on molecular mechanisms of complement-mediated killing initiated by either a complement-activating monoclonal antibody or antibody-cobra venom factor (CVF) conjugates. This project includes the analysis of cellular defense mechanisms against complement attack and their modulation by metabolic inhibitors. In particular, we want to investigate the role of membrane components in the slow degradation of C3b on complement-susceptible cells and of the rapid degradation on complement-resistant cells. Additional studies will elucidate the role of antigen expression and internalization of surface-bound complement components in determining complement susceptibility. The kinetics of binding of complement components C4, C5 and C9 will be studied. We will investigate the effect of adriamycin to enhance complement susceptibility. These studies are directed to identify the membrane targets of the adriamycin action and the mechanism by which adriamycin achieves the enhanced complement susceptibility. Based on the observation that immobilized adriamycin can enhance the complement susceptibility in vitro we wish to generate antibody conjugates with adriamycin, and to test them for their in vitro activity, their in vivo pharmacokinetic properties, and their therapeutic activity in tumor-bearing animals. We also wish to identify other complement-enhancing drugs and their mechanisms of action. The second area of research will focus on covalent conjugates of monoclonal antibodies with CVF as cytotoxic agents. Initially, we wish to find a structural basis for the recently discovered activity differences of CVF isolated from different Naja naja subspecies. The investigations on the effect of heterobifunctional cross-linking reagents on activity and pharmacokinetic properties of antibody-CVF conjugates will be continued with new cross-linking reagents. Another project is to analyze the localization of antibody-CVF conjugates into tumors. Subsequently, the immunotherapeutic effect of antibody-CVF treatment in tumor-bearing animals will be studied. Finally, monoclonal antibodies to CVF will be used as a tool to identify immunogenic epitopes and functional sites on CVF, cobra C3, and human C3 as an approach to study the structure/function relationships of these homologous proteins.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA035525-04
Application #
3173083
Study Section
Experimental Immunology Study Section (EI)
Project Start
1983-07-01
Project End
1991-06-30
Budget Start
1986-07-01
Budget End
1987-06-30
Support Year
4
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Georgetown University
Department
Type
School of Medicine & Dentistry
DUNS #
049515844
City
Washington
State
DC
Country
United States
Zip Code
20057
Vogel, Carl-Wilhelm (2004) Preparation of immunoconjugates using antibody oligosaccharide moieties. Methods Mol Biol 283:87-108
Juhl, H; Petrella, E C; Cheung, N K et al. (1997) Additive cytotoxicity of different monoclonal antibody-cobra venom factor conjugates for human neuroblastoma cells. Immunobiology 197:444-59
Zara, J; Pomato, N; McCabe, R P et al. (1995) Cobra venom factor immunoconjugates: effects of carbohydrate-directed versus amino group-directed conjugation. Bioconjug Chem 6:367-72
Ollert, M W; Kadlec, J V; David, K et al. (1994) Antibody-mediated complement activation on nucleated cells. A quantitative analysis of the individual reaction steps. J Immunol 153:2213-21
Ollert, M W; Kadlec, J V; Petrella, E C et al. (1993) Molecular basis of complement resistance of human melanoma cells expressing the C3-cleaving membrane protease p65. Cancer Res 53:592-9
Zara, J J; Wood, R D; Boon, P et al. (1991) A carbohydrate-directed heterobifunctional cross-linking reagent for the synthesis of immunoconjugates. Anal Biochem 194:156-62
Juhl, H; Petrella, E C; Cheung, N K et al. (1990) Complement killing of human neuroblastoma cells: a cytotoxic monoclonal antibody and its F(ab')2-cobra venom factor conjugate are equally cytotoxic. Mol Immunol 27:957-64
Ollert, M W; Frade, R; Fiandino, A et al. (1990) C3-cleaving membrane proteinase. A new complement regulatory protein of human melanoma cells. J Immunol 144:3862-7
Swartz, R P; Naai, D; Vogel, C W et al. (1988) Differences in uptake of mycobacteria by human monocytes: a role for complement. Infect Immun 56:2223-7
O'Keefe, M C; Caporale, L H; Vogel, C W (1988) A novel cleavage product of human complement component C3 with structural and functional properties of cobra venom factor. J Biol Chem 263:12690-7

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