SULKIN AND ALLEN 



INFLUENCE OF TEMPERATURE ON 

 ANTIBODY PRODUCTION IN BATS 



In planning studies on the influence of hibernation on the progress 

 of these experimental viral infections inbats, it seemed desirable to 

 determine the pattern of antibody production in these animals fol- 

 lowing peripheral inoculation of various arthropod-borne viruses.As 

 pointed out earlier, the unique thermoregulatory mechanism of bats 

 sets them apart from other animals and suggests this animal as an 

 ideal experimental host whose temperature and metabolism maybe 

 altered at will, permitting the influence of temperature on infection 

 and antibody production to be studied over extended periods. The use 

 of bats also permits the achievement of hypothermia without the use 

 of drugs or surgery which might have an independent effect on the 

 physiochemical balance of the host. 



A bacterial antigen was selected for a pilot experiment on the 

 effect of temperature on antibody production because of the ease 

 with which one candemonstrate agglutinating antibodies. The typhoid- 

 H antigen- antibody system was chosen as representing a relatively 

 simple immunization procedure and antibody assay technique re- 

 quiring very small serum samples, and the big brown bat was used 

 because it can withstand repeated bleeding by cardiac puncture. 

 One group of bats was maintained at room temperature (26° C) and 

 another in simulated hibernation (10° C), Rectal temperatures were 

 taken periodically. All bats received 3 intraperitoneal doses of 0.25 

 ml each of an 8- hour formalized broth culture of Salmonella typhosa 

 on days 0, 15 and 24 of the experiment. Several animals were bled 

 periodically and all were bled on the 35th day following the initial 

 immunizing dose. The antibody level of each serum sample was de- 

 termined by means of the tube agglutination test. The results indi- 

 cate that the ability of the big brown bat to produce antibody in 

 response to injections of a bacterial antigen is dependent upon its 

 body temperature, which parallels that ofthe environment (Fletcher 

 et al., 1962). After 35 days and 3 doses of antigen, over 70 per cent 

 of the animals had agglutinin titers ranging from 1:8 to 1:672, In 

 striking contrast, the bats held at 10° C failed to produce any de- 

 tectable antibody during this period. Some animals which had been 



382 



