Dogs And Mice Infection Wei Paragonimus Adcc Effect Of Schistosomula In Vitro Experimental Study

This article has discussed the probab reason why juvenile of Paragonimus westermani (P w) with invasiveness to new host could survive in paratanic host. The antibody-dependent cell mediated cytotoxcity of infected dogs or mice against juvenile of P w was investigated in vitro by observing the juveniles?ultrastructure and invasiveness to new host. The following points have been reported in this thesis: 1. During culturing in vitro the movement of juveniles and adhesion of effector cells to juvenilse were observed under microscopy. Under the presence of immune serum the effector cells including white blood cells of dog or mice and peritoneal phagocytes of mice could adhere to surface of j ttveniles after 12-hour incubation. The cell adherence kept increasing till the metacercarien-huellen reaction becoming more and more severely after 36-hour incubation. In contrast, the control groups with normal serum instead of immune serum didn抰 present these phenomena. The cotitrol groups without effector cells, which had immune serum, showed only increasing metacercarien- huellen reaction after 12-hour incubation. All juveniles in different groups kept activity during the experiment. 2.The ultrastructures of juveniles of Pw were observed under scanning electron microscopy. In experiment groups (dog抯 immune serum ?dog抯 WBC + juveniles, mice抯 immune serum ?mice抯 WBC + juveniles), after incubation, all surface of juveniles became eroded and swollen, spines disappeared, sensory pappilae disappeared or deformed. But in control groups (with normal serum instead of immune serum or without effector cells), ultrastructures of juveniles were similar to those 3 of normal juveniles. 3. The recovery rate of P w juveniles in mice was examined after re-infection. The recovery rates of juveniles in mice infected with juveniles from different experiment groups (mice?s immune serum + mice抯 WBC + juveniles, mice抯 immune serum + mice抯 peritoneal phagocytes + juveniles) and different control groups (mice抯 normal serum + mice抯 WBC + juveniles, mice抯 normal serum + mice抯 peritoneal phagocytes ?juveniles, mice抯 immune serum + juveniles)were 58 ?.71(%), 65 ?14.5(%), 57 ?.08(%), 63 ?.58(%) and 65 ?14.5(%)respectively, which had no significant difference compared with the recovery rate of juveniles in mice infected with metacercariae ( 58?1 O.06(%)). The juveniles were found mostly in muscles, body cavities and liver. Part of juvemiiles developed but still itnmatured. In this study, it was shown that the WBC from infected dog or mice and peritoneal phagocytes from infected mice could damage the teguments of Pw juveniles by ADCC, but the cytotoxicity had no affections on their vitalities and invasiveness. These results suggested that the host couldn抰 kill P w juveniles by only one kind of mechanism so that juveniles could survive in the host with strong vitalities for a long time.