PT - JOURNAL ARTICLE AU - François Bonnardel AU - Stuart M. Haslam AU - Anne Dell AU - Ten Feizi AU - Yan Liu AU - Virginia Tajadura-Ortega AU - Yukie Akune AU - Lynne Sykes AU - Phillip R. Bennett AU - David A. MacIntyre AU - Frédérique Lisacek AU - Anne Imberty TI - Proteome-wide prediction of bacterial carbohydrate-binding proteins as a tool for understanding commensal and pathogen colonisation of the vaginal microbiome AID - 10.1101/2020.09.10.291781 DP - 2020 Jan 01 TA - bioRxiv PG - 2020.09.10.291781 4099 - http://biorxiv.org/content/early/2020/09/10/2020.09.10.291781.short 4100 - http://biorxiv.org/content/early/2020/09/10/2020.09.10.291781.full AB - Lectins, such as adhesins and toxins, are carbohydrate-binding proteins that recognise glycans of cells and their secretions. While mediation of microbe-microbe and microbe-host interactions by lectins has long been recognised in the lung and gut, little is known about those in the vagina, where such interactions are implicated in health and various disease states. These include sexually transmitted infections, cervical cancer and poor pregnancy outcomes such as preterm birth. In this study, the curated UniLectin3D database was used to establish a lectin classification based primarily on taxonomy and protein 3D structure. The resulting 109 lectin classes were characterised by specific Hidden Markov Model (HMM) profiles. Screening of microbial genomes in the UniProt and NCBI NR sequence databases resulted in identification of >100 000 predicted bacterial lectins available at unilectin.eu/bacteria. Screening of the complete genomes of 90 isolates from 21 vaginal bacterial species showed that the predicted lectomes (ensemble of predicted lectins) of Lactobacilli associated with vaginal health are substantially less diverse than those of pathogens and pathobionts. Both the number of predicted bacterial lectins, and their specificities for carbohydrates correlated with pathogenicity. This study provides new insights into potential mechanisms of commensal and pathogen colonisation of the reproductive tract that underpin health and disease states.Author Summary Microbes play an important role in human health and disease. Bacteria use protein receptors called lectins to anchor to specific sugars (i.e. glycans) decorating the surface of proteins and cells. While these have been extensively studied in the mouth and gut, much less is known about how bacteria attach and colonise the lower female reproductive tract. This limits our understanding of how they contribute to sexually transmitted infections, cervical cancer and preterm birth. To address this, we designed and implemented a bioinformatics workflow to identify and classify novel lectins in 21 vaginal bacterial species implicated in reproductive tract health and disease. Our results show that species associated with infection and inflammation produce a larger variety of lectins thus enabling them to potentially bind a wider array of glycans in the vagina. These findings provide new targets for the development of compounds designed to prevent pathogen colonisation or encourage growth of commensal species.Competing Interest StatementThe authors have declared no competing interest.