Use of carbohydrates and peptides in studies of adhesion of pathogenic bacteria and in efforts to generate carbohydrate-specific T cells

The recognition of cell surface carbohydrates by E. coli and S. suis has been investigated. Use of synthetic oligosaccharides and their deoxy- and deoxyfluoro derivatives as inhibitors of the bacterial adhesins revealed that E. coli and S. suis were hydrogen bonded to different epitopes on the disaccharide galabiose. In addition, synthetic peptides were identified that inhibit the chaperone PapD which is required for assembly of protein subunits into the E. coli P pilus. Both adhesin-receptor interactions and subunit-chaperone interactions constitute targets for design of novel antibiotics. The T cell response to derivatives of immunogenic peptides that carry carbohydrate haptens has also been studied and carbohydrate-specific helper T cells were obtained on immunization of mice. An enhanced immune response against carbohydrate antigens may be useful in treatment of infectious disease and cancer.