IMMUNITY REACTIONS WITH AMCEB^, 



291 



Character of the immune bodies. — A few tests were made to determine 

 whether the destruction of the amoebte was accomplished by the combined 

 action of amboceptor and complement in a manner analogous to the 

 action of hsemolysins and bacteriolysins. The effect of heating is' shown 

 by the results in Table II. The serum of a rabbit immunized to amoebae 

 (race A) and B. prodigiosus was tested against the same mixture of 

 amcebffi and bacteria. One part of serum was diluted with 1.5 parts of 

 water for the purpose of heating at 70° and 78°. 



! Table II. — Showing effect of heat on immune serum. 



Lysis produced 



by heated immune 



serum. 



Dilution 



of 



immune 



serum. 



Temperature and duration oi heating. 



Unhealed 

 immune 

 serum. 



60°, one- 

 half hour. 



60°, 1 

 hour. 



60°, 3 

 hours. 



70°, one- 

 half hour. 



78°, one- 

 half hour. 



With complement 

 added: 

 Normal rabbit 

 serum— 



1 to 10 



lto5 



Without comple- 

 ment 



1 - 



( 1-10 



f ^"^ 



1 1-5 



1-10 



I 1-5 

 1 1-10 



Active. 



Active. 



None. 



Active. 



Active. 



None. 



Active. 



Active. 



None. 



Active. 



Active. 



None. 



Active. 



Active. 



None. 



Active. 



Active. 



None. 



Active. 



Active. 



None. 



Active. 



Active. 



Slight. 



Active. 



Active. 



Slight. 









Active. 

 None. 



Active. 

 Slight. 









Active. 

 None. 



Active. 

 Slight. 







Active. 

 Active. 

 Slight. 



Active. 

 Slight. 



Active. 

 Slight. 





This activity of the serum after exposure to relatively high degrees of tem- 

 perature seems at first a little unexpected. However, related phenomena have 

 been observed with other protozoa and even with bacteria. Thus Rossle (9) 

 found that an immune serum produced by the injection of paramoecia was not 

 inactivated after exposure for 30 minutes to a temperature of 70° C. However 

 Rossle does not describe this serum as a true cytolysin and, furthermore, it was 

 thermostable only when the injections were made with killed and not with living 

 paramoecia, Lareran and Mesnil (10) found that an immune serum for trypa- 

 nosomata was only partially inactivated after exposure to a temperature of 

 64° C for one-half to three-fourths of an hour. Later, Hamilton(ll) reported a 

 thermostabile bacteriolysin for an organism designated as the "Ruediger bacillus." 



However, these results with amoebae do not prove that the immune 

 body is thermostable, unless normal heated serum also shows no activity. 

 Accordingly, the effect of heat was tested both on normal serum and 

 on the serum of a rabbit which had been immunized. This rabbit 

 had formerly shown some immunity, its serum being active in 1 to 5 

 dilution. At the time of this test no injections of amcebse had been 

 given for 2 months and as seen in Table III, the unheated serum was 

 inactive. 



104912 3 



