Schistosoma Japonicum Lung-stage Schistosomula Comparative Analysis With Other Stages Of The Parasite Protein And Biochemical And Immunological Properties

Objectives: 1. To clarify the biochemical and immunological characters of the lung-stage schistosomula protein and the difference between the proteins of this stage and other development stages of Schistosoma japonicum; 2. to analyze and identify whether there were resistant persons against infection in hyper endemic area and the corresponding protective molecules.Methods: The proteins of different stages, SLAP, SHAP, SAWAand SPAP and their antiserum were prepared. The suspected resistantpersons and sensitive persons in schistosome infection were identified byinquiry the history of infested water contact, examination pathogens inthe stool, detection of specific antibodies in sera and B-ultrasonicexamination of liver and spleen. The proteins of various stages wereseparated by SDS-PAGE and stained by PAS for saccharides orCoomassie brilliant blue. Immunological features of antigens and themolecules suspected to be related to the resistance were analyzed byEITB and ELISA. The protective effect was observed with animalexperiment. Result: 1. Among four different developmental stages,there were significant differences in the electrophoresis bands of theirproteins. The specific 65-70 and 90 kDa glycoprotein were stage specificin SLAP. 2. By EITB, when lung-stage schistosomula protein immunizedmice serum (SLAPImMS) reacted with various proteins, the numberand intensity of reactive bands arranged from maximum to minimumwere SLAP, SHAP and SAWA. However, an inverse order wasobserved when these proteins reacted with both S.j infected rabbit serum(SjInRS), S.j adult worm proteins immunized rabbit serum (SAWAImRS)and S.j adult worm membrane immunized rabbit serum (SAWMImRS). The antigens of 70 and 50kDa in SLAP could be only recognized by the SLAPImRS. After SLAP immunization of mice, 22.4% reduction in egg burden was achieved. 3. hi hyper endemic area, some persons although frequently contacted with the infested water and had antibodies against S.j in their sera, but looked nice in appearance, no symptoms and signs and were negative in stool examination. They were included in the group of suspected resistants. Although, the expected resistant molecular were not ascertained in the examined five cases, it was found that protein weighted 38kDa in SAWA and SHAP could only be recognized by sera of the suspected resistants (3/5) by EITB. And besides, there were the antibodies against 97, 45-48kDa of SLAP, 97-127kD of SHAP, 97, 86, 45, 48and24kD of SAWA in sera of Microtus fortis (MF) .Conclusion: The biochemical and immunological features of SLAP and the difference among proteins of various stages were researched and demonstrated that the major change happened in the teguments composition of worms. The differences between the susceptible resistants and the non-resistant persons were distinct in the recognized protein bands, and the antibody against 38kDa in SAWA and SHAP only existed in sera of the suspected resistants. It was also found that some specific antibodies against schistosomulum were in sera of MF. This study offered some valuable evidences and materials for research the relationship between the parasite and host and in immunology of schistosomiasiso...