RT Journal Article SR Electronic T1 Pseudomonas aeruginosa lectin LecB impairs keratinocyte fitness by abrogating growth factor signalling JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e201900422 DO 10.26508/lsa.201900422 VO 2 IS 6 A1 Landi, Alessia A1 Mari, Muriel A1 Kleiser, Svenja A1 Wolf, Tobias A1 Gretzmeier, Christine A1 Wilhelm, Isabel A1 Kiritsi, Dimitra A1 Thünauer, Roland A1 Geiger, Roger A1 Nyström, Alexander A1 Reggiori, Fulvio A1 Claudinon, Julie A1 Römer, Winfried YR 2019 UL http://www.life-science-alliance.org/content/2/6/e201900422.abstract AB Lectins are glycan-binding proteins with no catalytic activity and ubiquitously expressed in nature. Numerous bacteria use lectins to efficiently bind to epithelia, thus facilitating tissue colonisation. Wounded skin is one of the preferred niches for Pseudomonas aeruginosa, which has developed diverse strategies to impair tissue repair processes and promote infection. Here, we analyse the effect of the P. aeruginosa fucose-binding lectin LecB on human keratinocytes and demonstrate that it triggers events in the host, upon binding to fucosylated residues on cell membrane receptors, which extend beyond its role as an adhesion molecule. We found that LecB associates with insulin-like growth factor-1 receptor and dampens its signalling, leading to the arrest of cell cycle. In addition, we describe a novel LecB-triggered mechanism to down-regulate host cell receptors by showing that LecB leads to insulin-like growth factor-1 receptor internalisation and subsequent missorting towards intracellular endosomal compartments, without receptor activation. Overall, these data highlight that LecB is a multitask virulence factor that, through subversion of several host pathways, has a profound impact on keratinocyte proliferation and survival.