Antibodies cross-reactive with E- and P-selectin block both E- and P-selectin functions

Area of Science:

• Immunology and Molecular Biology
• Inflammation Research

Background:

• E-selectin and P-selectin are key cell adhesion molecules induced during inflammation.
• These molecules mediate critical interactions between leukocytes and endothelial cells, as well as leukocytes and platelets.
• Existing monoclonal antibodies (MoAbs) targeting either E-selectin or P-selectin show therapeutic promise in animal models of inflammation.

Purpose of the Study:

• To generate novel MoAbs with broader therapeutic potential by targeting both E-selectin and P-selectin simultaneously.
• To evaluate the efficacy of these dual-target MoAbs in blocking selectin-mediated cellular functions.

Main Methods:

• Immunization of mice with cell lines engineered to express both human E-selectin and P-selectin.
• Selection of MoAbs based on their ability to bind to both E- and P-selectin.
• Functional assays to assess the inhibition of neutrophil and HL-60 cell adhesion to activated endothelial cells and platelet-cell rosetting.

Main Results:

• Three MoAbs (EP-5C7, EP-2C9, and EP-1D8) were generated that bind to both E- and P-selectin.
• All generated MoAbs effectively blocked E- and P-selectin-mediated functions, including cell adhesion and rosetting.
• These antibodies recognize a common or overlapping epitope within the lectin domains of both selectins.

Conclusions:

• Targeting functionally important epitopes shared by homologous proteins is achievable through selection for dual-reactivity antibodies.
• A potent blocking MoAb specific for both E- and P-selectin represents a promising therapeutic strategy.
• Such dual-target MoAbs may offer more effective and broader utility in treating acute and chronic inflammatory conditions.