The development of efficient
fungal vaccines is urgent for preventing life-threatening systemic
fungal infections. In this study, we prepared a synthetic, cell-based fungal
vaccine for preventing systemic
fungal infections using synthetic biology techniques. The synthetic cell EmEAP1 was constructed by transforming the Escherichia coli chassis using a de novo synthetic fragment encoding the
protein mChEap1 that was composed of the E. coli OmpA
peptide, the fluorescence
protein mCherry, the
Candida albicans adhesin Eap1, and the C-terminally transmembrane region. The EmEAP1 cells highly exposed the mChEap1 on the cell surface under
IPTG induction. The fungal
vaccine was then prepared by mixing the EmEAP1 cells with
aluminum hydroxide gel and CpG. Fluorescence quantification revealed that the fungal
vaccine was stable even after 112 days of storage. After immunization in mice, the
vaccine resided in the lymph nodes, inducing the recruitment of CD11c+ dendritic cells. Moreover, the
vaccine strongly activated the CD4+ T splenocytes and elicited high levels of anti-Eap1
IgG. By the prime-boost immunization, the
vaccine prolonged the survival time of the mice infected by the C. albicans cells and attenuated fungal colonization together with
inflammation in the kidneys. This study sheds light on the development of synthetic biology-based
fungal vaccines for the prevention of life-threatening
fungal infections.