Glycosylation-dependent galectin-receptor interactions promote Chlamydia trachomatis infection

LUJAN, A; LOSINNO A; DAMIANI MT (CO-CORRESPONDING AUTHOR); CROCI D; CAGNONI, A; RABINOVICH G; GAMBARTE J; MARIÑO, K

Buenos Aires

Conferencia; 3rd argentinian symposium on glycobiology; 2019

glyco.ar

Chlamydia trachomatis (Ct) constitutes the most prevalent sexually-transmitted bacterium worldwide. Chlamydial infections can lead to severe clinical sequelae including pelvic inflammatory disease, ectopic pregnancy, and tubal infertility. As an obligate intracellular pathogen, Ct must enter into a human cell to accomplish its entire life cycle. Consequently, Ct has evolved multiple molecular strategies to promote adhesion and invasion of host cells, including those involving both bacterial and eukaryotic glycans. We show that galectin-1 (Gal1), an endogenous lectin widely expressed in female and male genital tracts, promotes chlamydial infection. Through glycosylation-dependent mechanisms involving recognition of bacterial glycoproteins and Nglycosylated host cell receptors, Gal1 enhances Ct attachment to cervical epithelial cells. Gal1, mainly in its dimeric form, facilitates bacterial entry and increases the number of infected cells by promoting Ct-Ct and Ct-host cell interaction. The Gal1 effect was substantiated in vivo in mice lacking Gal1 or complex branched N-glycans. Thus, disrupting Gal1-N-glycan interactions may limit the severity of chlamydial infection by inhibiting bacterial invasion of host cells.