Cell Mimic Microarrays for Multivalent Pathogen Characterization and Detection

DESCRIPTION (provided by applicant): This research project aims to develop cell mimic microarrays for the profiling, characterization, and detection of pathogens. The proposed approach exploits a common mechanism at the initial stage of pathogen attack, na mely the recognition of and attachment onto host cells via multivalent interaction between receptor proteins on pathogens and carbohydrate (glycan) molecules on cell surfaces. Unlike the highly specific protein-protein interaction, the low and varying affi nity between a protein receptor and a single glycan molecule is compensated for by the presence of multiple interactions. It has been argued that the display of a high density of glycan molecules on the surface of a microarray can facilitate such multivale nt interaction. Carbohydrate microarrays have been successfully demonstrated in multivalent binding, including the detection of pathogens. Despite the initial successes, a significant limitation remains: most carbohydrate microarrays demonstrated to date u se carbohydrate molecules covalently attached to solid surfaces. The lack of mobility does not mimic cell surface processes in vivo where glycan groups associated with glycolipids and glycoproteins are in a fluidic lipid bilayer environment. Indeed, mobili ty is believed to be a significant factor in mediating multivalent interactions, e.g., in the dynamic clustering of glycan ligands on the host cell surface. It is the purpose of this SBIR proposal to develop a platform for carbohydrate microarrays based on a proprietary air-stable supported lipid bilayer possessing a high level of fluidity. Compared to other carbohydrate microarrays, the proposed fluidic array more closely mimics the cell surface environment and can be applied more efficiently in the study of pathogen adsorption. The specific aims are to fabricate fluidic carbohydrate microarrays based on glycol lipids incorporated into the air-stable supported lipid bilayers and to use plant lectin ConA and cholera toxin B-subunits (CTB) in proof-of-concept experiments. A long-term outcome will be the development of effective tools for the understanding and detection of pathogens, as well as for the development of treatment and prevention. This research project aims to develop cell mimic microarrays f or the understanding and detection of pathogens, as well as for the development of prevention and treatment of pathogen attack.