Peptides that mimic Candida albicans-derived beta-1,2-linked mannosides

beta -1,2-linked mannosides from Candida albicans phosphopeptidomannan (PPM ) bind to macrophages through a receptor independent from the macrophage a- linked mannose receptor and stimulate these cells to secrete immune mediato rs. Anti-beta -1,2-linked mannoside but not anti-alpha -linked mannoside an tibodies produced after immunization with neoglycoproteins protect animals from disseminated candidiasis. In this study, peptides that mimic beta -1,2 -linked mannosides were isolated using phage display methodology. A phage l ibrary expressing random peptides was panned with an anti-beta -1,2-linked mannoside monoclonal antibody (mAb). After three rounds of biopanning, the isolated phages were able to inhibit recognition of C. albicans by the mAb. Sixty percent of the phages had an identical DNA insert corresponding to t he peptide sequence FHENWPS that was recognized specifically by the mAb. In jection of KLH-coupled peptide into mice generated high titers of polyclona l antibodies against C. albicans yeast cell walls. The anti-FHENWPS antibod ies bound to C. albicans PPM and were inhibited by soluble beta -1,2-mannot etraose. Together, these data provide evidence for mimotopic activity of th e peptide selected by biopanning with the anti-beta -1,2-oligomannoside mAb .