CONSTITUTION OF IMMUNE-BODY 17 



immune-body do nob become free but remain attached to the 

 receptors of the corpuscles ; a certain amount can, however, 

 be dissociated at the higher temperatures on the addition of 

 fresh corpuscles. And it follows as a corollary that in like 

 conditions when immune-body is obtained by adding red 

 corpuscles to a fluid or suspension of corpuscles at C., 

 the immune-body so obtained has been in the free condition. 



OK THE CONSTITUTION OF IMMUNE-BODY 



As is well known, there are two chief views on this subject, 

 namely, that of Ehrlich and that of Bordet. According to 

 the former, the immune-body has a specific affinity for the 

 receptor of the cell, and another special, though not specific, 

 affinity for the complement ; it acts as a link between the 

 complement and the cell receptor ; that is, is an amboceptor. 

 According to Bordet, the immune-body produces some 

 physical or chemical change in certain molecules (the recep- 

 tors) which brings about a combining affinity for comple- 

 ment, the molecules of the latter then combining directly 

 with the receptors of the cells. The immune-body is a 

 sensitizer, substance sensibilisatrice. It is a mistake, however, 

 to suppose that Bordet believes that immune-body inflicts 

 some damage on the cell which makes it susceptible to the 

 entrance of complement ; that is sufficiently evident from 

 his statements with regard to the fixation of complement 

 by albuminoids and their anti-substances. All that is 

 meant in speaking of immune-body as a sensitizer is that, 

 on its combining with the corresponding antigen, comple- 

 ment enters into union with the latter. Accordingly, unless 

 it can be proved that complement combines directly with 

 immune-body, the explanation of the mechanism appears 

 to involve theoretical questions of similar nature according 

 to both views either the immune-body sensitizes the 

 receptor, leading to the combination of complement, or 



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