Microchimeric cells from the peripheral blood associated with cardiac grafts are bone marrow derived, long-lived and maintain acquired tolerance to minor histocompatibility antigen H-Y.
BACKGROUND
Although it has been well established that the microchimerism occurs in the peripheral blood of the recipients after various settings in both clinical and experimental organ transplantation, nevertheless, their roles in inducing and maintaining acquired transplantation tolerance are controversial. Furthermore, regarding the cell lineages, kinetics, and functions of the cells that constitute the microchimerism after organ transplantation, solid information is not available.


METHODS
Using rat heterotopic heart isografts from bone marrow chimeras between cross-sex and applying polymerase chain reaction with specific primers to rat sex determining region of Y chromosome, a relationship between a state of microchimerism and induction as well as maintenance of acquired tolerance to H-Y antigen were examined.


RESULTS
Microchimeric cells of the peripheral blood (MCPB) after cardiac grafting contain bone marrow-derived and radiation-sensitive cells. Furthermore, removal of the primary cardiac grafts revealed that microchimeric cells in the peripheral blood are long-lived cells, i.e., more than 6 months. When the female rats that had contained long-lasting MCPB, were innoculated with syngeneic male dendritic cells, failure to sensitize female toward male specific antigen H-Y was found to occur.


CONCLUSIONS
Thus it was suggested that radiation-sensitive, bone marrow derived, long-lived MCPB play a significant role in maintaining acquired transplantation tolerance to minor histocompatibility antigen H-Y.
Yano
Y
Y
Department of Research Surgery, National Children's Medical Research Center, 3-35-31 Taishido, Setagaya-ku, Tokyo, 154-8509 Japan.
Hara
M
M
Miyahara
T
T
Shibata
K
K
Onitsuka
T
T
Nawa
Y
Y
Li
X K
XK
Suzuki
S
S
Amemiya
H
H
Kimura
H
H
D000818:Animals; D001773:Blood Cells / Q000473:pathology* / Q000502:physiology; D001853:Bone Marrow / Q000473:pathology*; D016922:Cellular Senescence / Q000502:physiology; D002678:Chimera; D005260:Female; D006085:Graft Survival; D006182:H-Y Antigen / Q000276:immunology*; D016027:Heart Transplantation; D007108:Immune Tolerance; D008297:Male; D016133:Polymerase Chain Reaction; D051381:Rats; D011917:Rats, Inbred Lew
D006182:H-Y Antigen