IMMUNOLOGICAL COMPETENCE OF SMALL 



LYMPHOCYTES IN THE GRAFT-VERS US-HOST 



REACTION IN MICE* 



W. H. HiLDEMANN, W. D. LlNSCOTlf AND M. J. MORLINO 



Department of Infectious Diseases, School of Medicine, 

 University of California, Los Angeles 



Since tlie relatively recent demonstrations of the existence and 

 immunological nature of graft-versus-host reactions in mice 

 (Billingham and Brent, 1957) and chickens (Simonsen, 1957), this 

 subject has been explored so rapidly that a large hterature has 

 already accumulated. It is now weU known that when adult, 

 immunologically competent cells are injected into non-isologous 

 animals incapable of destroying these cells, a syndrome called 

 runt disease, homologous disease, secondary disease or more 

 generally transplantation disease, usually ensues. The basic 

 immunogenetic and pathological features of transplant-induced 

 disease have been recently reviewed (Billingham, 1959; Tyler, 

 i960; Oliner, Schwartz and Dameshek, 1961) and need not be 

 detailed here. From a clinical standpoint, reactions produced by 

 grafted cells against their hosts constitute a major barrier to the 

 induction of reciprocal tolerance and the repair of radiation injury. 

 Nevertheless, such reactions have provided a sensitive test system 

 for immunogenetic studies employing inbred lines of animals 

 (BiUingham and Brent, 1959; Simonsen and Jensen, 1959; Payne 

 andjaffe, 1961). 



* Aided by research grant C-4027 from the National Institutes of Health, 

 United States PubHc Health Service, Bethesda, Maryland. 



t Present address: Howard Hughes Medical Institute, Laboratories of Micro- 

 biology, Miami 36, Florida. 



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