Successful allogeneic leg transplantation in rats in conjunction with intra-bone marrow injection of donor bone marrow cells.
BACKGROUND
We have recently established a new method for bone marrow transplantation (BMT) in mice: bone marrow cells are directly injected into the intra-bone marrow (IBM) cavity. IBM-BMT induces persistent donor-specific tolerance and enhances the rapid recovery or reconstitution of the hematolymphoid system of donor origin without any signs of graft-versus-host disease (GVHD) or graft failure. Furthermore, the prior injection of fludarabine can reduce the irradiation dose to the sublethal level (4.5 Gy x 2). Therefore, we hypothesize that IBM-BMT plus fludarabine is applicable to allogeneic leg transplantation in rats.


METHODS
Brown Norway (BN; RT1An) rats were injected intravenously with 50 mg/kg of fludarabine phosphate, followed by sublethal fractionated irradiation (4.5 Gy x 2) 1 day before IBM-BMT. The hind limbs from Fischer 344 (F344; RT1Al) rats were transplanted on day 0, and bone marrow cells (3 x 10(7) cells/50 microL) obtained from the donor F344 rats were injected into the bone marrow cavity of the left tibias of the recipient BN rats.


RESULTS
The hematolymphoid cells in the recipient BN rats were completely reconstituted by the cells of the donor F344 rats. The limbs transplanted from the donor F344 rats were accepted for >1 year without any clinical signs of rejection (10 of 10). The lymphocytes of the BN rats showed tolerance to both donor-type and recipient-type major histocompatibility complex determinants in mixed lymphocyte reaction, but showed a significant response to the third-party major histocompatibility complex determinants.


CONCLUSIONS
Using a combination of the injection of fludarabine, low-dose irradiation, and IBM-BMT, we have succeeded in allogeneic limb transplantation without using any immunosuppressants after the operation. This strategy would be applicable to the transplantation of other vascularized organs in humans.
Esumi
Takashi
T
First Department of Pathology, Kansai Medical University, Moriguchi City, Osaka, Japan.
Inaba
Muneo
M
Ichioka
Naoya
N
Kushida
Taketoshi
T
Iida
Hirokazu
H
Ikehara
Susumu
S
D000818:Animals; D016026:Bone Marrow Transplantation / Q000379:methods; D005260:Female; D006085:Graft Survival; D006086:Graft vs Host Disease / Q000517:prevention & control; D006614:Hindlimb / Q000637:transplantation*; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D051381:Rats; D011914:Rats, Inbred BN; D011916:Rats, Inbred F344; D019172:Transplantation Conditioning / Q000379:methods*; D014184:Transplantation, Homologous / Q000379:methods*; D001084:Vidarabine Phosphate / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D014916:Whole-Body Irradiation
D007166:Immunosuppressive Agents; D001084:Vidarabine Phosphate; C042382:fludarabine phosphate