NATURAL AND IMMUNE ANTIBODIES 153 



sensitized cells alone but will unite with the latter only after they 

 have combined with complement. These authors ako found that 

 the substance resists heating to 56° C. and that it has biochemical 

 properties somewhat similar to the albumins. Manwarinj? (1906) 

 described a thermostable component of bovine serum whicli he 

 named ''auxilysin." It is probably the same as conglutinin. 



Heterophile Antibodies and Heterophile Antigens. — In 1911 

 Forssman discovered that a great variety of apparently otherwise 

 unrelated substances possessed in common an antigenic factor tliat 

 would stimulate rabbits to produce hemagglutinins and hemolysins 

 for sheep cells. These nonspecies specific antigenic substances have 

 been called heterophile antigens and the hemagglutinins and 

 hemolysins resulting from their injection are called heterophile 

 antibodies. The heterophile antigen present in sheep cells is dis- 

 tinct from the isophile or species specific antigen. This work was 

 extended by Forssman and Hintze (1912), Forssman and Fox 

 (1914), Pick (1913), Doerr and Pick (1913), and many others. 

 More recent reviews and investigations are those of Tanigiechi 

 (1921), Landsteiner and Simmons (1923), Powell (1926), Hooker 

 (1926), Bull (1928), Jungeblut (1929), Landsteiner and Levine 

 (1932) and Meyer and Morgan (1935). As a result of this work 

 the following conclusions relative to heterophile antigens have 

 been formulated and generally accepted. They have been reported 

 as present in the tissues (especially the kidney) of the guinea pig, 

 horse, cat, dog, camel, mouse, chicken, gills of carp and pike, in the 

 plasms and urine of the horse, in the red blood cells of the sheep, 

 goat and chicken and also in certain bacteria such as B. enteritidis 

 of Gaertner, B. paratyphosus B and B. dysenteriae (Shiga). As a 

 rule, with the exception of the chicken, when tlie heterophile 

 antigen occurs in the tissues of an animal, it is absent from tlie 

 red cells of that animal and conversely, when it is present in the 

 red cells, it is absent from the tissues. It is interesting to note that 

 while it is found in tlie chicken and in tlie mouse, it is not present 

 in either the pigeon or the rat. While it is present in B. para- 

 typhosus B, it is absent from E. typhosa. The Forssman antigen 

 found in many animal tissues seems to be made up of a protein 

 and perhaps a combination of lipoid and polysaccharide whereas 

 the active substance in bacteria seems to be polysaccharides alone. 

 Schiff and Adelsberger (1924) and others seem to have established 



