MODIFICATION OF RUNT DISEASE 



361 



cells were used from either normal adult C57BL/6 animals or 

 C57BL/6 adults previously sensitized by the skin grafting method 

 described above. Fig. 9 shows the weight-gain record of a 

 representative litter of 6 mice, three of the members of which were 

 treated with 27 million spleen cells in a single injection, half from 



2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 

 DAYS OF AGE 



Fig. 9. Weight-gain record of a litter of 6 newborn 

 C57BL/6 mice. Three received 27 milhon spleen 

 cells, half from DBA/i adult donors and half from 

 C57BL/6 adult donors which had previously rejected 

 DBA/i skin grafts (open circles). The three controls 

 (sohd dots) received only the DBA/i spleen ceUs. 

 Two of the three animals receiving the ceU mixture were 

 fully protected. One was only partially protected 

 from runt disease and died on the twenty-sixth day. 



an adult C57BL/6 which had previously rejected bilateral DBA/i 

 skin grafts and half from a normal DBA/ 1 donor. Two of the 

 three animals receiving the cell mixture were completely protected 

 from runt disease while the third showed only partial protection. 

 Three controls receiving only the DBA/i portion of the injection 

 promptly succumbed, as expected, to runt disease. This protective 

 effect, previously observed by Billingham and Brent (1959) and by 

 Siskind and Thomas (1959), is equally strong when the isologous 



