[Induced tolerance to cardiac allografts with intrathymic injection of donor spleen cells].
OBJECTIVE
To study the methods and mechanisms of immune tolerance in cardiac transplantation.


METHODS
Male DA rat hearts were transplanted to male Lewis rats using Ono's model and randomly divided into four groups: untreated (group I), intrathymic injection of 2.5 x 10(7) DA splenocytes to Lewis rat (group II), intraperitoneal injection of 1 ml rabbit anti-rat lymphocyte serum (ALS) to Lewis recipient (group III), intrathymic injection of 2.5 x 10(7) DA splenocytes combined with intraperitoneal injection of 1 ml rabbit anti-rat lymphocyte serum (ALS) to Lewis recipient (group IV). 21 days later heart transplantation was performed. Mean survival time (MST), histological changes and mixed lymphocyte reaction (MLR) were measured after operation.


RESULTS
In the group of intrathymic injection of spleen cells combined with ALS treatment, the survival time of heart allografts [MST: (81.8 +/- 7.6)d] was significantly longer than in the groups I [MST: (7.3 +/- 1.0) d], group II [MST:(7.8+/- 1.0)d], and group III [MST(8.2 +/- 1.2) d, P < 0.01]. Only a few inflammatory cells infiltrated in cardiac allografts in group IV. MLR of group IV were significantly decreased compared with those of the normal control (P < 0.01).


CONCLUSIONS
The role of thymus as a special site for induction and maintenance of specific immunological unresponsiveness to organ allografts was confirmed. T cell clonal deletion may play an important role in this immune tolerance.
Guo
H
H
Department of Surgery, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China.
Wu
Q
Q
Xie
S
S
Zhang
Q
Q
Yang
X
X
Shao
M
M
D000818:Animals; D000961:Antilymphocyte Serum / Q000008:administration & dosage / Q000276:immunology*; D006082:Graft Enhancement, Immunologic / Q000379:methods*; D016027:Heart Transplantation / Q000276:immunology*; D007108:Immune Tolerance; D007274:Injections, Intraperitoneal; D007519:Isoantigens / Q000008:administration & dosage / Q000276:immunology*; D008297:Male; D011817:Rabbits; D051381:Rats; D011917:Rats, Inbred Lew; D017208:Rats, Wistar; D013154:Spleen / Q000166:cytology; D016042:Transplantation, Heterotopic / Q000276:immunology
D000961:Antilymphocyte Serum; D007519:Isoantigens