IMMUNE RESPONSE IN COLD EXPOSURE 



mals in terms of (1) the degree of response, for example, the total 

 amount of antibody produced, (2) the rate of appearance of antibody, 

 (3) the "type" of antibody produced, and (4) the influence of the period 

 of immunization and/or cold exposure on the response of animals to 

 major and minor antigens when immunized with a multiple antigen 

 system. 



This information may serve toelucidatetheroleof the "specific" 

 factor of immunity, that is, circulating antibody during periods of 

 cold exposure, and at the same time serve to clarify the response of 

 the immune mechanism to immunization with multiple antigens both 

 during and prior to cold exposure. 



In all of these studies, the rabbit was the experimental animal of 

 choice. The animals were housed in a walk- in cold room maintained 

 at a temperature of 4^C. Prior to the beginning of the immunization 

 schedules, the rabbits were allowed to "adapt" for a period of one 

 week, after which they were clipped until fur remained only on the 

 head and the extremities. New fur was periodically clipped. The 

 animals were given food ad libitum, and water was changed fre- 

 quently. Open wire cages were used to allow free movement of air. 

 Only one rabbit was housed in each cage to prevent huddling. In most 

 of the studies, rabbits weighing approximately 2.5 to 3.0 kg were 

 immunized with three weekly intra- muscular injections of equal 

 parts of antigen and Freund's adjuvant (Freund, 1947). 



Blood samples were obtained via cardiac puncture, the serum 

 separated and merthiolate added in a 1:10,000 final concentration. 

 All of the rabbits used in these studies were carefully selected in 

 order to control genetic variations. Litters of six or more were 

 raised for this investigation, and each litter was divided into equal 

 study groups of experimental and control animals. The serum 

 samples were then subjected to a variety of immuno- chemical 

 analyses which were designed to detect any difference in the serum 

 proteins of the "cold exposed" versus the "non-cold exposed" 

 rabbits. 



The immune response of an animal to the administration of an 

 infective agent is best measured in terms of the antibody formed and 

 directed against the microorganism and its antigenic spectrum. 



Ill 



