Establishment of orthotopic liver transplantation model of inbred rats with spontaneous tolerance and study on role of CD8~+ CD28~- T cells

Objective To establish the orthotopic liver transplantation(OLT) model of inbred rats and explore the role of spleen CD8~+CD28~T cells in spontaneous tolerance of the model.Methods The OLT model of inbred rats was established according to double-sheeve technique.The proportional changes of spleen CD8~+CD28~-T cells were determined by flow cytometry.Spleen CD8~+CD28~-T cells were sorted by complement-dependent cytotoxicity and immunomagnetic beads.The suppressing activity of the spleen CD8~+CD28~-T cells was tested by mixed lymphocyte reaction in vitro.Results An OLT model of spontaneous tolerance was established between BN(donor) and LEW(recipient) inbred rats.After OLT,spleen CD8~+CD28~-T cells in the spontaneous tolerance model were elevated to 23.7% 7.2%,which was more than that in the normal control(5.4% 1.5%) and acute rejection model 6.0% 1.3%).The spleen CD8~+CD28~-T cells isolated from the spontaneous tolerance model but not acute rejection model could inhibit the proliferation of mixed lymphocyte reaction.Conclusions The spleen CD8~+CD28~-T cells isolated from the spontaneous tolerance model are an unique kind of suppressor T cells.Meanwhile,they might play an important role in induction of spontaneous tolerance.