364 IMMUNOLOGICAL STUDIES 



in the field of cancer research, is toward the use of various sedi- 

 mentable particles obtained from cell homogenates as immunizing 

 antigens for the production of cytotoxic antisera. One would 

 expect, however, that the likelihood of obtaining tissue-specific 

 antisera would be greater if simpler antigenic preparations were 

 employed. In any case the present experiments warrant an ex- 

 ploration of the effectiveness of mild procedures, tending to 

 extract surface constituents, for the preparation of immunizing 

 antigens for use in the study of problems of malignant growth as 

 well as in problems of normal development. 



The Concept of Natural Auto-Antibodies 



During the earlier investigations by the author on the location 

 of fertilizin in the egg, an antifertilizin was extracted from below 

 the surface of the egg ( Tyler, 1940 ) , after the fertilizin had been 

 found to be the material of the gelatinous coat of the egg. This 

 antifertilizin behaved like antifertilizin derived from sperm, in 

 neutralizing fertilizin, agglutinating a suspension of eggs, form- 

 ing a precipitation membrane on the surface of the gelatinous 

 coat, etc. Since the interaction of fertilizin and antifertilizin is 

 considered analogous to that of antigen and antibody, this find- 

 ing indicated that two substances capable of interacting in that 

 manner could be extracted from a single cell. Various reports on 

 auto-antibodies in the immunological literature could be similarly 

 interpreted as indicating the existence of mutually complemen- 

 tary substances in the same cell or tissue. It was therefore pro- 

 posed that this situation is a general feature of living cells and 

 that it might provide a basis for interpretation and further inves- 

 tigation of specific immunological problems and of problems of 

 growth and differentiation (Tyler, 1942, 1947, 1955b). A some- 

 what similar concept of mutually interacting complementary sub- 

 stances being involved in processes of growth and differentiation 

 has been developed by Weiss (1947, 1949, 1950, 1955). 



The term auto-antibody concept was used to lend emphasis 

 to the idea that each of the various macromolecular substances of 

 which cells are constructed bears the same sort of relation to an- 

 other of these substances as do antigen and antibody, and they 



