Characteristics and anti-adhesion activity of chicken scFv antibodies against Helicobacter pylori HpaA

Helicobacter pylori (H. pylori) adheres to gastric epithelial cells via adhesins like HpaA, causing persistent colonization and inflammation. In this study, we isolated chicken single-chain fragment variable (scFv) antibodies targeting HpaA from a chicken immune scFv antibody library. Four antibodies (H2-D1, H1-B11, H2-D9, and H2-A3) were analyzed, including evaluation of characteristics as well as anti-adhesion effects. They maintained binding activity under simulated gastrointestinal pH conditions and demonstrated high thermal stability. These antibodies exhibited specific binding and high affinity to the recombinant HpaA protein as well as HpaA proteins present in clinical H. pylori strains. Flow cytometry analysis revealed that these scFv antibodies significantly inhibited the adhesion of HpaA protein and various H. pylori strains to AGS cells. Our findings suggested that these antibodies hold potential for diagnostic and therapeutic use against H. pylori infection, providing a foundation for the development of anti-adhesion reagents and antibody drugs for H. pylori infection.