Immunogenicity and Antigenicity of Opisthorchis felineus Proteins

Three antigenic preparations of the human liver fluke Opisthorchis felineus were analyzed and characterized by immunochemical and serological reactions. The antigenic profiles of the excretory-secretory antigen (ES-Ag) contained 21 predominant protein bands in the range of 25-283 kDa, 20 protein bands in the range of 24-302 kDa of the somatic antigen (S-Ag), and 33 protein bands in the range of 23-313 kDa of the egg antigen. Stimulation of the immune system by these antigen preparations resulted in the production of specific mouse and hamster antibodies, which confirmed their immunogenicity. The antigenic characteristic of O. felineus antigens were measured by indirectELISA with specific sera. The average antibody titers when interacting with ES-Ag, S-Ag and E-Ag were in the range of 1:300, 1:3, 680 and 1:1,600, respectively. The 105-, 105- and 250-kDa protein bands of the ES-Ag, S-Ag and E-Ag preparations, respectively, were specific to positive serum from dogs infected with O. felineus. The activity and specificity of the antigen preparations in ELISA were positively correlated with dot immunoblot and Western blot assays.