BACTERIAL ANTIGENS AND ENDOTOXINS 



a modification suggested to me in early discussions with 

 Dr Joshua Lederberg, namely, that a formal equivalent to 

 a clonal selection theory could be elaborated at a subcellular 

 level. If in an activated cell antibody production is a function 

 of self-replicating units at a lower genetic level than the 

 chromosomes and if these units are subject to limited muta- 

 tion then a process of selective proliferation of those units 

 corresponding most closely to the antigenic determinant in 

 question must be considered as a possibility. If this were 

 combined with the possibility of movement of such units from 

 one activated cell to another, any of the results so far 

 described could be met, still within the framework of an 

 approach in which the action of antigen as a direct template 

 is excluded. If the acceptance of selective intracellular pro- 

 liferation of competing subcellular units becomes necessary, 

 it will be a complicating factor, particularly because it will 

 make experimental decision between template and selective 

 theories even more difficult. It will not, however, be in any 

 way incompatible with the clonal selection theory presented 

 here on a cellular basis since in each cell the dominant 

 subcellular entity would determine the immunological com- 

 petence of the clone. 



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 BiLLiNGHAM, R. E. (1958). Pediatric Research Conference, Dallas, 13-15 



March 1958. 

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