Monoclonal antibody to human tissue plasminogen activator

Area of Science:

• Immunology
• Biochemistry
• Molecular Biology

Background:

• Tissue plasminogen activator (t-PA) is crucial for fibrinolysis.
• Monoclonal antibodies offer high specificity for therapeutic targets.
• Characterizing specific t-PA variants is important for understanding their roles.

Purpose of the Study:

• To produce and characterize a monoclonal antibody against one-chain tissue plasminogen activator (t-PA) from human melanoma cells.
• To evaluate the antibody's specificity, binding affinity, and functional inhibitory effects on t-PA activity.

Main Methods:

• Hybridoma technology was employed, fusing mouse myeloma cells (SP-1) with spleen cells from t-PA-immunized mice.
• Monoclonal antibody production was achieved using mouse ascites.
• Specificity was tested against t-PA from various sources (melanoma, porcine heart, human urine).
• Functional assays assessed inhibition of fibrinolytic and amidolytic activities, and fibrin-binding capability.

Main Results:

• A hybridoma producing a specific IgG1 monoclonal antibody to melanoma-derived t-PA was successfully generated.
• The antibody demonstrated high specificity, reacting only with melanoma t-PA and not with t-PA from other sources.
• Antibody activity from mouse ascites was 50-fold stronger than polyclonal antibodies from mouse serum.
• The monoclonal antibody firmly bound t-PA, significantly inhibited its fibrinolytic activity, but only partially inhibited amidolytic activity.
• Fibrin-binding ability and binding to reduced/non-reduced t-PA forms were unaffected.

Conclusions:

• A potent and specific monoclonal antibody targeting melanoma-derived one-chain t-PA was developed.
• This antibody effectively inhibits the fibrinolytic function of t-PA, suggesting potential therapeutic applications.
• The antibody's specificity and binding characteristics provide insights into t-PA structure-function relationships.