Comparison Of The Immunosuppressive Activity Between Cuticle Coat Proteins And Secrete Proteins From Steinernema Glaseri

Entomopathogenic nematodes are a kind of important bio-control factor which can suppress the host insects’ immunity. Both Surface coat proteins (SCPs) and secrete proteins (SPs) from Steinernema glaseri infective juveniles were proved to play important roles in promoting infection of entomopathogenic nematodes. In order to research the mechanism of these two prpteins, so that them could be used in the bio-control. In this study, the SCPs were extracted with ethanol and the SPs were induced by Galleria mellonella homogenates, then the similarity and difference between them were compared.1The collection and purify of secrete materials which produced by Steinernema glaseri. the SPs were induced by Galleria mellonella homogenates. induce the Steinernema glaseri secrete activity products, through the methods of washing by PBS, using ultrafiltratted concentration, etc. acquire the pure secrete proteins.Separate the proteins from the surface or secrete materials of Steinernema glaseri, using PAGE to separate the contents of these two kinds of proteins. The contents these proteins are very complex, there are more than15bands every proteins, and the molecular weight are generally less than66KD. The result of SDS-PAGE shows that also there are some similar with each other, the differents are very obvious. The surface coat proteins has more bands and the secrete proteins has two bands of high concentration. The2D of surface coat proteins and secrete proteins from Steinernema glaseri infective juveniles shows that, in the44KD position,there are obvious spots in the gel. That is identical with the proteins with have been reported.2We compared the bio-activity of these two proteins, and the analysis of insect hemocyte lytic activity of SCPs and SPs from Steinernema glaseri in vitro or in vivo shows that, both of them can lytic host insects’hemocyte, and the activity of SCPs is more powerful than that of SPs. The detection of enzymes’activity indicated that, no matter in vitro or in vivo, both of them can suppresse polyphenol oxidase activity. The experiments of immunity suppresses indicated that, no matter in the suppression of host insects’ phagocytic or encapsulate, the activity of SPs is more powerful than that of SCPs. That’s maybe there are some active factors contained in the SPs. And these factors are the chief source of the immune activity. The another reason maybe that the proteins contained in SCPs could suppressed with each other. This weaken of immune activity may relation with the Steinernema glaseri’s autoimmunity and interspecific competition.