Fig 1.
The predicted molecular properties of Cs1 protein and expression of different fragments of Cs1.
(A) The predicted molecular properties of Cs1 protein. SP: signal peptide; N: N-terminus; TR: tandem repeat; C: C- terminus. (B) Expression and purification of rCs1 by 12% SDS-PAGE. Lane 1, BL21(DE3) cells containing the recombinant pET28α-Cs1 homolog without IPTG induction; lane 2, BL21(DE3) cells containing the recombinant pET28α-Cs1 homolog with IPTG induction; lane 3, supernatant of lysed BL21(DE3) cells containing the recombinant pET28α-Cs1 homolog with IPTG induction; lane 4, pellet of lysed BL21(DE3) cells containing the recombinant pET28α-Cs1 homolog with IPTG induction; lane 5, the recombinant protein purified by affinity purification. (C) Expression and purification of rCs1TR. Lanes 1–5, different fractions of purified rCs1TR protein. (D) Expression and purification of rCs1N. Lanes 1–7, different fractions of purified rCs1N. (E) Expression and purification of rCs1C+TR. Lanes 1–7, different fractions of purified rCs1C+TR. Lane M in (B)-(E) shows molecular mass standards.
Fig 2.
Comparison of the sensitivity and specificity of rCs1-ELISA and ESP-ELISA.
(A) rCs1-ELISA. (B) ESP-ELISA. The two methods were used to assay a total of 114 serum samples, including 35 samples infected with clonorchiasis (Cs) and 36 uninfected samples (Healthy), 15 samples infected with schistosomiasis japonica (Sj), 15 samples infected with paragonimiasis westermani (Pw) and 13 samples infected with cysticercosis (Ts). OD = optical density.
Fig 3.
Western blotting of recombinant and native Cs1.
Blots were probed with anti-rCs1 monoclonal antibody (Lanes 1, 3, and 5) or S/P20 (Lanes 2, 4, and 6). Lanes 1 and 2, rCs1; Lanes 3 and 4, C. sinensis ESPs; Lanes 5 and 6, crude antigens of adult C. sinensis. M, protein molecular weight marker.
Fig 4.
Immunolocalization of Cs1 in adult C. sinensis.
Fluorescence microscopy images (left) and corresponding optical images (right) of adult worms are shown. Cs1 localization is represented in (A) and (B) and the negative controls are shown in (C) and (D). (E) is 2.5 times the magnification of the boxed area in (A). Scale bar equals 500 μm in (A)-(D) and 250 μm in (E).
Fig 5.
Localization of Cs1 (green) in adult C. sinensis by confocal microscopy.
C. sinensis adults were incubated with (A) anti-rCs1 mAb (Cs1-2-6-3) or (B) negative control (S/P20). (C) is 2.5 times the magnification of the boxed area of (A). Scale bar equals 500 μm in (A) and (B), and 250 μm in (C).