The Hyr1 protein from the fungus Candida albicans is a cross kingdom immunotherapeutic target for Acinetobacter bacterial infection
A. baumannii (AB) and C. albicans (CA) cells were allowed to interact physically under hyphae permissive conditions. The cells were stained with ConA (Candida cell wall red) and Syto13 (nuclei green). Acinetobacter binds to (block arrows), and kill wild-type or hyr1/hyr1+HYR1 complemented C. albicans hyphae as observed by degraded fungal nuclei (thin arrows) (A). The bacteria cease to attach to and kill hyphae of C. albicans hyr1/hyr1 mutant strain (A). Anti-Hyr1p-N antibodies abolish attachment of the bacteria to the fungal filaments (B) and inhibit Acinetobacter viability (diminished nuclear staining = dead cells in presence of antibody) (C). Under flow mixed-species biofilm conditions, Acinetobacter binds to wild-type or hyr1/hyr1+HYR1 complemented C. albicans biofilm (black arrow) and forms a thick white layer (white arrow), whereas the bacterial binding is considerably reduced on the C. albicans hyr1/hyr1 mutant cells (D). The extent of A. baumannii binding to C. albicans wild-type, hyr1/hyr1, or hyr1/hyr1+HYR1 complemented strains is microscopically depicted, where the cells are stained with Syto13. Note the dead hyphae in the wild-type and hyr1/hyr1+HYR1 complemented strains but not in the hyr1/hyr1 mutant (white arrows) (E). Bars in A and E are 10 μm.