Detection of host DNA sequences including the H-2 locus of the major histocompatibility complex in schistosomes

Abstract

SUMMARYThe mouse type 2Alu(B2) sequence was detected in both DNAs ofSchistosoma mansoniandS. japonicumexcept for the cercarial stage by the polymerase chain reaction (PCR). Using several kinds of mouse STMS (sequence tagged microsatellite site) primer sets, PCR products related to the host were found in the DNAs ofS. mansonias well as ofS. japonicum. Products could be detected only in the DNA ofS. japonicumusing certain STMS primer sets. The fact that no products could be amplified from the DNAs of both parasites when other kinds of STMS primer sets were used suggests unequal incorporation of the host DNA into the schistosomes. Furthermore, the sequence of the N-terminal domain of H-2, the mouse major histocompatibility complex (MHC), was detected in the DNAs fromS. mansonimiracidium, male adult andS. japonicumadults, whereas the sequence of the C2domain of H-2 was found only in the DNAs ofS. japonicumadults. This evidence that host DNA sequences, including the class I MHC, exist heterogeneously in the DNAs of schistosomes might provide an important insight for further understanding of host-parasite immune interactions.