| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2000: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1999: ¥2,200,000 (Direct Cost: ¥2,200,000)
|
|---|
| Research Abstract |
Background. We previously established a cyclophosphamide (CP)-induced tolerance system in rodent skin graft models. In this study, we applied this system to rat liver transplantation.
Methods. Lewis recipients were inoculated on day -2 with spleen and bone marrow cells (SC+BMC) from Dark Agouti (DA) donors, followed by 100 mg/kg CP on day 0. On day 25, DA livers were orthotopically grafted. We assessed the alloresponses to the donors of the long-term surviving recipients, using the second skin grafting and in vitro assay.
Results. The recipients that had been treated with SC+BMC and CP survived for more than 165 days. None of control group that received SC+BMC alone (mean survival times [MST]=13.8 days), CP alone (MST=40.0), SC+BMC from third-party PVG rats and CP (MST=45.0), or no treatment (MST=13.8) survived over 50 days. The donor-specific tolerance was confirmed by second skin grafts onto recipients with permanent DA liver grafts, which accepted DA skins (MST>75) but not PVG (MST=8.3). However, the lymphocytes from the tolerant recipients showed alloresponse to DA in vitro. To investigate whether the T helper type 2 deviation contributed to this "split tolerance, " we assessed the production of cytokines in mixed lymphocyte reaction. Interleukin 2 and interferon-[gamma] were detected but interleukin 4 was not.
Conclusions. These data showed that this protocol induced split tolerance in rat liver transplantation and, furthermore, the mechanism of split tolerance was not due to T helper 2 deviation.
|
