Sap2and Hsp90Antigens And Antibodies In Rabbit Models Of Candida Albicans Infection

Candida albicans (C. albicans) is one of the most frequent opportunisticpathogens in fungal infection. In recent years, the incidence of invasive infection isincreasing, and its pathogenesis is very complex. In the absence of specific clinicalsigns and complex pathogenesis, the diagnosis of candidiasis is very difficult. So far,there is no a widely recognized, effective, simple and non-invasive method todiagnosis of candidiasis.Hsp90and Sap2are two virulent factors of C. albicans. They can induce thehosts to produce protective antibodies, and play important roles in the process of C.albicans infection. Sap2,as an proteinase, can degrade proteins of host to enhanceattachment by the removal of host barriers. Hsp90, as a molecular chaperone, is alsoinvolved in a variety of physiological processes. Studies have shown that Hsp90andSap2play an important role in the diagnosis, treatment and immune protection of C.albicans infection.Our lab has constructed pET28a-Sap2and pET28a-Hsp90prokaryoticexpression vectors, and stored the recombinant plasmids. In this study, we preparedHsp90and Sap2recombinant proteins with higher purity. Then, we successfullyobtained polyclonal antibodies of the two proteins from rabbits’ serum. Sixteen whiterabbits(eight male and eight female),very nearly in weight, were randomly devidedinto two unequal groups in quantity. After being immunocompromised, fourteenexperimental rabbits were injected with1ml inoculum containing5×107C.albicansthrough ear vein to establish C. albicans infection model, while the control wereinjected in the same way. We use indirect ELISA method to detect the change ofantibodies, and indirect competitive ELISA method to detect the change of antigens inthe course of infection. We found that the Hsp90and Sap2antigens and antibodies inthe experimental groups have their changeable tendency with the development ofinfection, and the control group had no obvious change. By analyzing the product ofthe two antigens and antibodies, we can infer the level of infection, and the data haveimportant implication in the early diagnosis for candidiasis.