162 IMMUNITY. THEORIES OF IMMUNITY 



bohydrates and fats. Recent developments in immunologic research 

 would indicate, therefore, that a complex toxic glucosid that can be 

 hydrolyzed by enzymes may act as an antigen. 



The intimate relationship of lipoids to complement fixation reactions, 

 especially in syphilis, has naturally led to investigations regarding the 

 possibility of lipoids acting as true antigens. In testing for the Wasser- 

 mann reaction the use of lipoids in the form of tissue extracts to serve 

 as an antigen does not mean that it is a true antigen; in fact, experi- 

 mental work indicates quite strongly that these lipoidal substances are 

 incapable of producing antibodies when injected into animals. 



Much and others have worked with lipoids secured from a strepto- 

 thrix, and which is called "nastin," and they assert that this substance 

 may be used in immunizing animals with the production of an antibody 

 yielding complement fixation, with nastin as the antigen. Similar 

 results have been described for the fatty substances from tubercle bacilli 

 ("tuberculonastin"). Kleinschmidt l accepts the antigenic 'nature of 

 nastin in reactions, but was unable to secure antibodies by immunizing 

 rabbits with this substance. 



Ritchie and Miller 2 could demonstrate no antigenic activity in the 

 lipoids of serum or corpuscles. Thiele 3 calls attention to the fact that 

 lipoids possess no specificity, and that they cannot act as antigens with 

 the production of antibodies. On the other hand, Meyer 4 has reported 

 the production of specific complement-fixation antibodies by immuniz- 

 ing rabbits with acetone-insoluble lipoidal substances obtained from 

 various teniae. He has also found the acetone-insoluble fraction of 

 tubercle bacilli to serve as antigens in complement-fixation reactions 

 with antibodies of the tubercle bacillus, and much more effectively than 

 with the protein residue of the bacilli. Beigel 5 has observed that after 

 injecting lecithin in rabbits an increase occurs in the lipase content of 

 the blood and tissues, with the presence of complement-fixing anti- 

 bodies, and Jobling and Bull 6 have found an increase in serum lipase 

 after immunizing with red corpuscles. 



It will be noticed, therefore, that the results of various investigations 

 regarding the true antigenic properties of lipoids are not in accord. 

 It should be emphasized that the complement-fixation reaction does not 

 constitute a reliable index to the study of this problem, as so little is 



1 Berl. klin. Wochschr., 1910, 47, 57. 2 Jour. Path, and Bact., 1913, 17, 427. 



3 Zeit. f. Immunitat., 1913, 16, 160. 



4 Zeit. f. Immunitat., 1910, 7, 732; 1911, 9, 530; 1912, 16, 355. 

 6 Deut. Arch, f . klin. Med., 1912, 106, 47. 



6 Jour. Exper. Med., 1912, 16, 483. 



