Organ-specific antigens of Clonorchis sinensis

Abstract

This study was carried out to find out specific proteins from different organs of Clonorchis sinensis. Crude extract, organ-specific and excretory-secretory (ES) proteins were analyzed by immunoblot with infected human sera. The bands of 7- and 17-kDa were main component of intestinal fluid and ES protein and commonly found in all organspecific proteins. The 17-kDa protein was observed from ES antigen, intestinal fluid, eggs and sperms, 26- and 28-kDa proteins were from the uterus, vitellaria, and ovary, and 34-, 37-, 43- and 50-kDa proteins were mainly from the testis and sperms. Serum of mice immunized with sperms reacted to the 50-kDa protein by immunoblotting and immunohistochemical staining showed a positive reaction at the seminal receptacle and seminiferous tubule. The present results show that the 7-kDa protein is a common antigen of every part or organ of C. sinensis, but different organs express their specific antigenic protein bands.

Fig. 1

SDS-PAGE analysis of soluble proteins extracted from several organs of Clonorchis sinensis. Lane 1, crude antigen; lane 2, vitellaria; lane 3, uterus; lane 4, ovary; lane 5, egg; lane 6, testis; lane 7, sperm; lane 8, excretory-secretory proteins; lane 9, intestinal fluid.

Fig. 2

Immunoblot patterns of anti-human IgG antibody to several antigens of Clonorchis sinensis. C, crude extract; V, vitellaria; U, uterus; ES, excretory-secretory protein; IF, intestinal fluid; E, eggs; O, ovary; H, head; T, testis; S, sperms.

Fig. 3

Immunoblot of immunized serum with the sperm protein of Clonorchis sinensis. A, normal mouse serum; B, immunized mouse serum (arrow, 50-kDa band).

Fig. 4

Immunohistochemical staining of adult Clonorchis sinensis. A. Normal control serum shows no positive reaction. B. Staining with the immune serum shows positive staining in the seminal receptacle (center arrow) and the seminiferous tubule (arrows).