Engineering a yeast double-molecule carrier for drug screening.

With the advantages of unicellular eukaryotic structure and easy manipulation， yeast becomes a popular tool for biochemical， genetic and medicinal studies. In order to construct an efficient anti-inflammatory drug screening platform， we engineered yeast as a double-molecule carrier， of which an inserted domain (I domain) of lymphocyte function-associated antigen 1 was displayed on yeast surface and a green fluorescent protein (GFP) was expressed inside cytosol. The I domain specifically targeted a surface marker of mammalian cells， intercellular adhesion molecule 1， whose number is correlated with the level of cellular inflammation. Examination of GFP intensity enables swift quantification of the yeast-mammalian cell binding and thus it reflects inflammatory potency， herein the inflammatory index， of a chemical imposed to cells. The inflammatory potency of a total of 1340 chemicals was indexed. Among them， 1 inflammation-inducing and 1 inflammation-reducing compounds were verified both in vitro and in vivo. Our method demonstrated a swift， facile and high-throughput screening platform at the protein level for inflammation and related diseases drug discovery without using sophisticated instruments.