Peptide mimotopes of carbohydrate antigens.

Carbohydrate structures have been identified as significant antigens for bacterial, viral, and fungal pathogens as well as targets on human tumor cells. Many of these antigens are poorly immunogenic in humans, requiring extensive adjuvant sublimation. Although conjugate carbohydrate vaccines appear promising, there are limitations of using carbohydrate formulations. An alternative approach is to use surrogate antigens for some carbohydrates. We are developing peptides that mimic carbohydrates which might be further manipulated to induce responses that target biologically important carbohydrates expressed on pathogens and on tumor cells. We have shown that peptide mimotopes of carbohydrates induce immune responses to carbohydrate structures with in vivo and vitro functionality. Model systems include the Neisseria group C meningococcal polysaccharide; the histo-blood group-related antigens expressed on tumor cells; and mannose, sialyl, and histo-blood group-related carbohydrate epitopes expressed on human immunodeficiency virus.