Fig. 3.

Expression and characterization of CsCatD2. (A) Productions of rCsCatD2 and anti-CsCatD2. The rCsCatD2 was produced as an insoluble protein in E. coli. Proteins were analyzed by SDS-PAGE and stained with Coomassie blue (left). Anti-CsCatD2 was produced by immunizing mice with purified rCsCatD2. The specificity of anti-CsCatD2 was confirmed by immunoblot (right). Lane 1, Escherichia coli lysate control; lane 2, IPTG-induced E. coli lysate; lane 3, affinity-purified rCsCatD2. (B) Localization of CsCatD2. IFA was performed with anti-CsCatD2 against sections of C. sinensis adult worms. The slide was observed with a confocal laser scanning microscope (×10 magnification). Scale bar indicated 100 mm. (C) Antigenic property of CsCatD2. The time course of antibodies targeting CsCatD2 in rats experimentally infected with C. sinensis was analyzed. Four rats were infected with 100 C. sinensis metacercariae and the sera from each rat were collected at 0 (0W), 2 (2W), 4 (4W), 6 (6W), 9 (9W), and 12 (12W) weeks post-infection. The purified rCsCatD2 was separated on 12% SDS–PAGE, transferred onto nitrocellulose membrane, cut into strips, and then probed with sera from four rats.