DISCUSSION 179 



DISCUSSION 



Medawar: Do these transformed tumours provoke the formation of 

 humoral antibodies ? 



Feldman: These tumours have a pecuHar behaviour in relation to 

 humoral antibodies. Unlike other tumours with which we have been 

 working in C3H mice, these tumours of the SBLi and SBLx sublines 

 do not elicit isohaemagglutinins when grafted in foreign strains. How- 

 ever, isohaemagglutinins which are formed by homografts of normal 

 tissues of the same genetic constitution (C57BL) can be absorbed by the 

 SBLi tumour cells. We tested sera after four successive transplanta- 

 tions of these tumours and we failed to fnid any signs of agglutinin 

 response. 



E. Klein: Do you mean that you cannot get haemagglutinins by 

 injection of the *' original" tumour line? Or do you mean the 

 "changed'* line? 



Feldman: Neither of them elicit haemagglutinins in C3H mice, no 

 matter which procedure or which route of transplantation we use. 



E. Klein : Do you see any difference in the quantity of absorption if 

 you use both lines ? 



Feldman: We have published some data along these lines (Yaffe, D. 

 and Feldman, M. [1959]. J. nat. Cancer Inst., 23, 132). The story is 

 complicated because absorptions with the transformed line were done 

 with tumours which were taken from the foreign host, whereas 

 absorptions with the strain-specific lines were done with tumours which 

 were grown in the strain of origin. Therefore the results are not clear- 

 cut. 



E. Klein: You might get around this problem if you injected both 

 tumour lines in newborn animals of the same genotype. 



Feldman : That could be done. However, what we have found is that 

 the homo transplantable subline (SBLx), growing in hosts of foreign 

 strains, does not absorb anti-CsyBL isohaemagglutinins. Since these 

 tumours were taken from genetically foreign hosts it might be thought 

 that these tumours would be saturated with isohaemagglutinins. This 

 seems very improbable, because for saturation you will need at least a 

 degree of isohaemagglutinins which will be detected serologically. 



