CHAPTER 8 



LYMPHOCYTIC RESPONSE TO 

 TISSUE TRANSPLANTATION* 



T. N. HARRIS AND SUSANNA HARRIS 



It has long been recognized that tissues cannot be successfully transplanted 

 from animals of one species to another (heterologous transplant) or even 

 between individuals of the same species (homologous transplant), with the 

 exception of some special cases of homologous transplantation such as those 

 involving members of an inbred strain (isologous) or homozygous twins. In 

 recent years there has been a great deal of interest and activity in relation 

 to this remarkable phenomenon of tissue specificity. Although many prob- 

 lems are still unsolved, there has been a great increase in the extent of our 

 understanding of the mechanisms involved in the rejection of transplanted 

 tissue and even the development, by Billingham, Brent, and Medawar, of 

 experimental means of induction of prolonged acceptance of homologous 

 grafts (actively acquired tolerance). 1 The studies in this area in recent dec- 

 ades have led to the general recognition of immunologic mechanisms as 

 being involved in the rejection of transplanted tissue, and in many of the 

 studies to be reviewed below, the cellular responses to transplanted tissue 

 have been examined from the point of view of the immunologic reaction or 

 defense of the host. 



STUDIES OF CELLULAR RESPONSE 

 TO TISSUE TRANSPLANTATION 



Cellular Response at the Site of Transplantation 



In early studies the cellular reaction of the host tissues was studied as 

 essentially a local phenomenon. In 1912 DaFano observed lymphocytic in- 



* The preparation of this paper was aided by Grant H 869 of the National Heart Institute. 

 United States Public Health Service. 



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