A mannose-binding lectin displays Candida growth inhibition and adhesion reduction to host cells.

DEL RÍO, M.; DE LA CANAL, L; NAVARRO, M; PINEDO, M.; MORA, H; REGENTE, M.

Congreso; LI Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2015

Candida cell wall consists of a skeleton of glucans and chitin, with an outer layer enriched in mannoproteins. Lectins can show antimicrobial abilities through their interaction with glycoconjugates on pathogen surfaces. We have described a sunflower mannose-binding lectin (Helja), which inhibits the growth of C. parapsilosis. The aim of this work was to assess the Helja effect on C. guillermondii (Cg) growth and its adhesion to host cells, and to explore the interaction of the lectin with the outer N- and O-mannoproteins, using yeast mutants with specific mannosylation defects. Helja (100 μg/mL) was able to reduce by 75 % the growth of the wt strain. To determine the contribution of the fungal mannosylation on Helja effect, we used a Cg pmr1D null mutant, which displays both O- and N-mannan severely truncated. This strain showed similar growth inhibition in the presence of Helja than wt yeast. The lectin was also tested for its effect on Cg adhesion to buccal epithelial cells, detecting a significant binding reduction of wt strain to these cells. However, the pmr1D mutant showed similar levels of adhesion both in the presence and absence of Helja. Thus, the nature and extent of Cg mannosylation appear to be essential for Helja interference on fungal adhesion to host cells, but the mannan defect assessed is not sufficient to bypass the growth inhibition displayed by this lectin.