Use of protein microarray to identify gene expression changes of Yersinia pestis at different temperatures

Yersinia pestis is a bacterium that is transmitted between fleas, which have a body temperature of 26 degrees C, and mammalian hosts, which have a body temperature of 37 degrees C. To adapt to the temperature shift, phenotype variations, including virulence, occur. In this study, an antigen microarray including 218 proteins of Y. pestis was used to evaluate antibody responses in a pooled plague scrum that was unadsorbed, adsorbed by Y. pestis cultivated at 26 degrees C, or adsorbed by Y pestis cultivated at 26 and 37 degrees C to identify protein expression changes during the temperature shift. We identified 12 proteins as being expressed at 37 degrees C but not at 26 degrees C, or expressed at significantly higher levels at 37 degrees C than at 26 degrees C. The antibodies against 7 proteins in the serum adsorbed by Y. pestis cultivated at 26 and 37 degrees C remained positive, suggesting that they were not expressed on the surface of Y. pestis in LB broth in vitro or specifically expressed in vivo. This study proved that protein microarray and antibody profiling comprise a promising technique for monitoring gene expression at the protein level and for better understanding pathogenicity, to find new vaccine targets against plague.