An immunodiffusion analysis of some antigens of Schistosoma mansoni adults
Damian, R.T.
Exp Parasitol 18(2): 255-265
1966
DOI: 10.1016/0014-4894(66)90024-5
Accession: 030027856
Living adult schistosomes were washed, quick-frozen, and lyophilized. Saline extracts were prepared from these worms as antigen for immunodiffusion tests. Antisera were obtained from rabbits initially injected into the toe pads with whole worm homogenates in Freund incomplete adjuvant followed by intravenous booster injections. Fourteen sera from 7 rabbits were used to analyze the antigenic composition of the S. mansoni saline extract (SMSE), both by the double-diffusion tube technique of Preer and the double-diffusion plate technique of Ouchterlony. Total numbers of bands in the Preer tests were determined by plotting band position (P) against dilution of SMSE. All normal serum and saline controls were negative. From 3 to 10 bands appeared when different antisera were set against SMSE. Ouchterlony analysis of these same sera and SMSE revealed from 4 to 11 bands, with all controls being negative. No reactions of nonidentity or partial identity were observed. By making many 2-serum combinations against SMSE in 3-basin plates, a minimum of 11 bands could be identified. Of 14 sera tested, 3 gave equal band numbers by both the Preer and Ouchterlony techniques. Ten sera gave more bands by the plate method whereas the tube method revealed more bands with one serum. Two bands, designated 4 and 7, are considered to represent the major antigens since they developed with each serum and were usually dense and sharp in appearance. Besides variations among antisera produced by different rabbits, variations among successive bleedings from a single rabbit were encountered. The present analysis was compared by immunodiffusion plates to an independent analysis published earlier by Kagan and Norman (1963). Test antigens were SMSE and a Chaffee's extract of S. mansoni. The prior use of simple antisera (giving few bands with either antigen) permitted the proof of 2 relationships in the 2 systems identity of their no. 2 band and my no. 4; and nonidentity of their no. 5 and my no. 7. With these established relationships as reference points, the comparison of 2 other, more complex antisera was made. The results indicated a good deal of correspondence in the 2 analyses, thereby confirming a part of Kagan and Norman's analysis. The main differences seen were quantitative although several qualitative differences were noted.