Insight into the host-parasite interplay by proteomic study of host proteins copurified with the human parasite, Schistosoma japonicum.

The tegument proteins of schistosome have attracted the most attention in studies of host-parasite interplay, while the host proteins acting at the host-parasite interface remained largely elusive. Here, we undertook a high-throughput proteomic approach to characterize the schistosome-adsorbed host proteins. Fifty five distinct host proteins were confidently identified in S. japonicum samples, including cercaria, schistosomula, adults, eggs, and miracidia, together with tegument and eggshell preparations, of which 23 and 38 host proteins were identified in adult worms and eggs, respectively. Among the schistosome-adsorbed host proteins, host neutrophil elastases were found in the granuloma initiated by schistosome egg deposition, implying that the host innate immune molecules could participate in the granuloma formation for fighting against schistosome invasion, except for the adaptive immune system. In addition, some host proteins, such as proteinase inhibitor and superoxide dismutase, might be utilized by schistosome to counteract or attenuate the host attacks. These parasite-adsorbed host proteins will provide new insights into the host immune responses against schistosome infection, the evasive behavior of the adult worms, and the granuloma formation, which could render an in-depth understanding for the host-parasite interplay.