CHAPTER LXXVII 

 ORIGIN OF ANTIBODIES 



KATHARINE M. HOWELL 



Nelson Morris Institute for Medical Research, Michael Reese Hospital, Chicago 



The origin of antibodies has been sought by investigators since Jenner, Pasteur, 

 Behring, and others first perceived that the body had a mechanism of defense against 

 introduced blood-foreign material. It has been proved many times over that when 

 such a foreign material, antigen, is injected into an animal, an antibody is elicited that 

 possesses the power of reacting specifically with the antigen introduced, destroying 

 or modifying its action or neutralizing its poison. 



Antibodies have not as yet been isolated in pure state; in fact, it has never been 

 proved that they exist as material objects. Their exact chemical nature, therefore, is 

 unknown; however, they are generally believed to be protein, or so closely attached to 

 one or another protein (euglobulin or pseudoglobulin) of the immune serum that sep- 

 aration has been impossible. A number of investigators have isolated almost pure 

 antibodies.' Wells^ has concisely summarized the chemistry of antibodies by stating 

 that like the enzymes they are recognized by what they do rather than by what they 

 are. In 1904 Ehrlich sought to explain the origin of antibodies on the basis of struc- 

 tural chemistry by his ingenious side-chain theory. The consequences of this theory, 

 the experimental evidences, and its present status are adequately discussed in other 

 chapters of this volume. 



Experimentally, the origin of antibodies has been approached from both the posi- 

 tive and the negative side. Proof of a positive nature has been offered by examining 

 organ extracts from immune animals, by immunizing various tissue cultures in vitro, 

 by causing the proliferation of special types of cells, or by stimulating the function of 

 particular organs. Negative methods of approach to the problem of antibody forma- 

 tion have been through damaging tissues which possibly produce antibodies with in- 

 jurious substances; through extirpation of organs; through blocking the reticulo- 

 endothelial system with colloids. 



ORGAN EXTRACTS 



Extracts of most of the organs and of the tissues of the body have been examined 

 for antibody content to determine whether or not the organ in question might either 

 produce or store antibodies. The titre of the extracts from normal animals has been 

 compared to that of the corresponding organ extracts from immunized animals, and 

 the latter in turn has been compared to the animal's serum. Dififerent criteria have 

 been employed for measuring the antibody content of organ extracts. 



Bacteriolysin was detected by Pfeiffer and Marx^ in extracts of spleen, bone 



' See chaps. Iv, Ixx, Ixxvii in this volum;. 



* Wells, H. G.: Chemical Aspects of ImmunUy, chap. iv. New York, 1925. ^-iCf^ \ Q A / 



3 FieiSer, R., and Ma.ix.; Ztschr.f. Hyg. u. Infektionskrankh., 27, 2^2. 1898. .s ^.■-. ,. 



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