[Preliminary study of cercaria antigen of Schistosoma japonicum before and after ultraviolet irradiation].
OBJECTIVE
To study the changes in the constituents of the cercaria antigen of Schistosoma japonicum before and after ultraviolet irradiation.


METHODS
The cercaria of Schistosoma japonicum were exposed to ultraviolet light (UV) irradiation at a dose of 400 mgrW/cm2 for 1 min, and the UV-irradiated cercaria antigen (UVCA) and normal cercaria antigen (NCA) were simultaneously analyzed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting.


RESULTS
At least 2 antigens with relative molecular mass (Mr) of 212 000 and 82 000 were identified in UVCA but not in NCA by SDS-PAGE analysis, and the concentrations of the antigens with Mr of 116 000, 26 000 and 16 000 in UVCA were significant higher than those in NCA. On the other hand, the antigenic molecule with Mr of 67 000 in NCA was recognized by serum from pigs vaccinated with UV-attenuated cercariae, but not by serum from pigs with Schistosoma japonicum infection. Antigens with Mr of 79 000 and 94 000 were apparently more strongly reactive with the former porcine serum than with the latter.


CONCLUSIONS
The results suggest that all the novel antigens arising from or increased by UV exposure, or antigens specifically recognized by serum from pigs vaccinated by UV-attenuated carcariae may be the principal factors in the highly protective immunity provoked by irradiated cercariae.
Li
Hua
H
Department of Parasitology, First Military Medical University, Guangzhou 510515, China.
Chen
Xiao-Guang
XG
Yang
Pei-Liang
PL
Zhou
Xiao-Hong
XH
Shen
Shu-Man
SM
Peng
Hong-Juan
HJ
Wu
Kun
K
D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology*; D004195:Disease Models, Animal; D011817:Rabbits; D012549:Schistosoma japonicum / Q000276:immunology / Q000528:radiation effects*; D012554:Schistosomiasis japonica / Q000276:immunology*; D013552:Swine; D014466:Ultraviolet Rays; D014611:Vaccination
D000947:Antigens, Helminth