Orally delivered single-domain antibodies against gastrointestinal pathogens.

Single-domain antibodies (sdAbs) are exceptionally stable proteins that are suitable for oral delivery. sdAbs have been used to control gastrointestinal (GI) infections caused by bacteria, viruses, and parasites. sdAbs can be delivered to the GI tract as native soluble protein or by using bacteria or transgenic plants as delivery vehicles. sdAbs can be further stabilized using protein engineering techniques or formulation technology. sdAbs may find utility in fighting infectious diseases, antimicrobial resistance, and microbiome engineering. Single-domain antibodies (sdAbs) are exceptionally stable fragments derived from the antigen-binding domains of immunoglobulins. They can withstand extreme pH, high temperature, and proteolysis, making them suitable for controlling gastrointestinal (GI) infections in humans and animals. sdAbs may function in their native soluble form, although different derived protein formats and the use of delivery vehicles can be useful for improved oral delivery. We discuss selected examples of the use of orally delivered sdAbs for protecting humans and animals against GI infections caused by pathogenic bacteria, viruses, and parasites. We finally provide perspectives on how sdAbs may be applied industrially and what challenges should be overcome for orally delivered sdAbs to reach the market. [ABSTRACT FROM AUTHOR]