Molecular mimicry of carbohydrate receptors and its application for the control of infectious diseases

点击翻译按钮获取中文摘要

Many kinds of infectious agents, such as viruses and bacteria, invade target cells through their binding to carbohydrate receptors expressed on the target cell surfaces. Since their specificities to these carbohydrate receptors do not change even after these infectious agents undergo antigenic shift or mutations, it would be possible to use these carbohydrate receptors for the protection from these infectious diseases. However, the preparation of a large amount of carbohydrate receptors is technically difficult. Thus, in this study, using the New castle disease virus (NDV)-carbohydrate receptor (sialic acid) interaction as a model, a search for peptide surrogates which can mimic the carbohydrate structure of the receptor was performed, and their protective effcicacies were evaluated against NDV infection.Three individual peptide sequences, EVSHPKVG, WVTTSNQW and SGGSNRSP, which have potentials to bind to hemagglutinin-neuraminidase of NDV were identified by the biopanning method using phage display system. The binding specificities of these peptides presented on phages were confirmed by the ELISA competition assay using chicken antiserum to NDV. The synthetic peptides designed based on the results did not inhibit the hemagglutination by inactivated NDV, but partially neutralized the infection of NDV in vitro. In the future, it will be necessary to modify these peptides sequences, for example substitution of amino acids, to improve their abilities to bind to NDV and to inhibit NDV infection. It is also important to examine the protective efficacies of them against NDV in vivo for clinical application.