Identification of the resistance of a novel molecule heat shock protein 90α (HSP90α) in Microtus fortis to Schistosoma japonicum infection

Microtus fortis is a naturally resistant vertebrate host of Schistosoma japonicum by preventing completion of parasiteʹs life cycle. Sera of M. fortis were found to have anti-schistosome effect in vitro and in vivo. In order to identify genes associated with the anti-schistosome effect of M. fortis, we screened a M. fortis marrow cDNA expression library by expression cloning and identified a 331-bp clone gC14.75. It was the homologue of heat shock protein 90α (HSP90α). Full-length of M. fortis HSP90α gene, Mf-HSP90α, was amplified according to gC14.75 and Cricetulus griseus HSP90α. To test the potential anti-schistosome function of Mf-HSP90α, we prepared conditioned medium of Mf-HSP90α and added it to schistosomula cultured in vitro. It caused 27.0% schistosomula death rate in 96 h, which was considerably higher than that of negative control. We transferred Mf-HSP90α by retroviral expression vector pLXSN into mice to investigate its anti-schistosome effect in vivo. Compared with those of DMEM injection control, mice injected with Mf-HSP90α recombinant retrovirus had 40.8% worm burden reduction and 57.9% reduction in liver eggs per gram (LEPG) indicating its anti-schistosome effect in vivo. Taken together, our results suggested Mf-HSP90α as a novel anti-schistosome molecule in vitro and in vivo.